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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/irqflags.h>
22 #include <linux/seccomp.h>
23 #include <linux/nodemask.h>
24 #include <linux/rcupdate.h>
25 #include <linux/refcount.h>
26 #include <linux/resource.h>
27 #include <linux/latencytop.h>
28 #include <linux/sched/prio.h>
29 #include <linux/sched/types.h>
30 #include <linux/signal_types.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 <linux/sched/rtg.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_run_ctx;
45 struct capture_control;
46 struct cfs_rq;
47 struct fs_struct;
48 struct futex_pi_state;
49 struct io_context;
50 struct mempolicy;
51 struct nameidata;
52 struct nsproxy;
53 struct perf_event_context;
54 struct pid_namespace;
55 struct pipe_inode_info;
56 struct rcu_node;
57 struct reclaim_state;
58 struct robust_list_head;
59 struct root_domain;
60 struct rq;
61 struct sched_attr;
62 struct sched_param;
63 struct seq_file;
64 struct sighand_struct;
65 struct signal_struct;
66 struct task_delay_info;
67 struct task_group;
68 struct io_uring_task;
69 
70 /*
71  * Task state bitmask. NOTE! These bits are also
72  * encoded in fs/proc/array.c: get_task_state().
73  *
74  * We have two separate sets of flags: task->state
75  * is about runnability, while task->exit_state are
76  * about the task exiting. Confusing, but this way
77  * modifying one set can't modify the other one by
78  * mistake.
79  */
80 
81 /* Used in tsk->state: */
82 #define TASK_RUNNING			0x0000
83 #define TASK_INTERRUPTIBLE		0x0001
84 #define TASK_UNINTERRUPTIBLE		0x0002
85 #define __TASK_STOPPED			0x0004
86 #define __TASK_TRACED			0x0008
87 /* Used in tsk->exit_state: */
88 #define EXIT_DEAD			0x0010
89 #define EXIT_ZOMBIE			0x0020
90 #define EXIT_TRACE			(EXIT_ZOMBIE | EXIT_DEAD)
91 /* Used in tsk->state again: */
92 #define TASK_PARKED			0x0040
93 #define TASK_DEAD			0x0080
94 #define TASK_WAKEKILL			0x0100
95 #define TASK_WAKING			0x0200
96 #define TASK_NOLOAD			0x0400
97 #define TASK_NEW			0x0800
98 #define TASK_STATE_MAX			0x1000
99 
100 /* Convenience macros for the sake of set_current_state: */
101 #define TASK_KILLABLE			(TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
102 #define TASK_STOPPED			(TASK_WAKEKILL | __TASK_STOPPED)
103 #define TASK_TRACED			(TASK_WAKEKILL | __TASK_TRACED)
104 
105 #define TASK_IDLE			(TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
106 
107 /* Convenience macros for the sake of wake_up(): */
108 #define TASK_NORMAL			(TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
109 
110 /* get_task_state(): */
111 #define TASK_REPORT			(TASK_RUNNING | TASK_INTERRUPTIBLE | \
112 					 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
113 					 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
114 					 TASK_PARKED)
115 
116 #define task_is_traced(task)		((task->state & __TASK_TRACED) != 0)
117 
118 #define task_is_stopped(task)		((task->state & __TASK_STOPPED) != 0)
119 
120 #define task_is_stopped_or_traced(task)	((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
121 
122 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
123 
124 /*
125  * Special states are those that do not use the normal wait-loop pattern. See
126  * the comment with set_special_state().
127  */
128 #define is_special_task_state(state)				\
129 	((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD))
130 
131 #define __set_current_state(state_value)			\
132 	do {							\
133 		WARN_ON_ONCE(is_special_task_state(state_value));\
134 		current->task_state_change = _THIS_IP_;		\
135 		current->state = (state_value);			\
136 	} while (0)
137 
138 #define set_current_state(state_value)				\
139 	do {							\
140 		WARN_ON_ONCE(is_special_task_state(state_value));\
141 		current->task_state_change = _THIS_IP_;		\
142 		smp_store_mb(current->state, (state_value));	\
143 	} while (0)
144 
145 #define set_special_state(state_value)					\
146 	do {								\
147 		unsigned long flags; /* may shadow */			\
148 		WARN_ON_ONCE(!is_special_task_state(state_value));	\
149 		raw_spin_lock_irqsave(&current->pi_lock, flags);	\
150 		current->task_state_change = _THIS_IP_;			\
151 		current->state = (state_value);				\
152 		raw_spin_unlock_irqrestore(&current->pi_lock, flags);	\
153 	} while (0)
154 #else
155 /*
156  * set_current_state() includes a barrier so that the write of current->state
157  * is correctly serialised wrt the caller's subsequent test of whether to
158  * actually sleep:
159  *
160  *   for (;;) {
161  *	set_current_state(TASK_UNINTERRUPTIBLE);
162  *	if (CONDITION)
163  *	   break;
164  *
165  *	schedule();
166  *   }
167  *   __set_current_state(TASK_RUNNING);
168  *
169  * If the caller does not need such serialisation (because, for instance, the
170  * CONDITION test and condition change and wakeup are under the same lock) then
171  * use __set_current_state().
172  *
173  * The above is typically ordered against the wakeup, which does:
174  *
175  *   CONDITION = 1;
176  *   wake_up_state(p, TASK_UNINTERRUPTIBLE);
177  *
178  * where wake_up_state()/try_to_wake_up() executes a full memory barrier before
179  * accessing p->state.
180  *
181  * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is,
182  * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
183  * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
184  *
185  * However, with slightly different timing the wakeup TASK_RUNNING store can
186  * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not
187  * a problem either because that will result in one extra go around the loop
188  * and our @cond test will save the day.
189  *
190  * Also see the comments of try_to_wake_up().
191  */
192 #define __set_current_state(state_value)				\
193 	current->state = (state_value)
194 
195 #define set_current_state(state_value)					\
196 	smp_store_mb(current->state, (state_value))
197 
198 /*
199  * set_special_state() should be used for those states when the blocking task
200  * can not use the regular condition based wait-loop. In that case we must
201  * serialize against wakeups such that any possible in-flight TASK_RUNNING stores
202  * will not collide with our state change.
203  */
204 #define set_special_state(state_value)					\
205 	do {								\
206 		unsigned long flags; /* may shadow */			\
207 		raw_spin_lock_irqsave(&current->pi_lock, flags);	\
208 		current->state = (state_value);				\
209 		raw_spin_unlock_irqrestore(&current->pi_lock, flags);	\
210 	} while (0)
211 
212 #endif
213 
214 /* Task command name length: */
215 #define TASK_COMM_LEN			16
216 
217 enum task_event {
218 	PUT_PREV_TASK   = 0,
219 	PICK_NEXT_TASK  = 1,
220 	TASK_WAKE       = 2,
221 	TASK_MIGRATE    = 3,
222 	TASK_UPDATE     = 4,
223 	IRQ_UPDATE      = 5,
224 };
225 
226 /* Note: this need to be in sync with migrate_type_names array */
227 enum migrate_types {
228 	GROUP_TO_RQ,
229 	RQ_TO_GROUP,
230 };
231 
232 #ifdef CONFIG_CPU_ISOLATION_OPT
233 extern int sched_isolate_count(const cpumask_t *mask, bool include_offline);
234 extern int sched_isolate_cpu(int cpu);
235 extern int sched_unisolate_cpu(int cpu);
236 extern int sched_unisolate_cpu_unlocked(int cpu);
237 #else
sched_isolate_count(const cpumask_t * mask,bool include_offline)238 static inline int sched_isolate_count(const cpumask_t *mask,
239 				      bool include_offline)
240 {
241 	cpumask_t count_mask;
242 
243 	if (include_offline)
244 		cpumask_andnot(&count_mask, mask, cpu_online_mask);
245 	else
246 		return 0;
247 
248 	return cpumask_weight(&count_mask);
249 }
250 
sched_isolate_cpu(int cpu)251 static inline int sched_isolate_cpu(int cpu)
252 {
253 	return 0;
254 }
255 
sched_unisolate_cpu(int cpu)256 static inline int sched_unisolate_cpu(int cpu)
257 {
258 	return 0;
259 }
260 
sched_unisolate_cpu_unlocked(int cpu)261 static inline int sched_unisolate_cpu_unlocked(int cpu)
262 {
263 	return 0;
264 }
265 #endif
266 
267 extern void scheduler_tick(void);
268 
269 #define	MAX_SCHEDULE_TIMEOUT		LONG_MAX
270 
271 extern long schedule_timeout(long timeout);
272 extern long schedule_timeout_interruptible(long timeout);
273 extern long schedule_timeout_killable(long timeout);
274 extern long schedule_timeout_uninterruptible(long timeout);
275 extern long schedule_timeout_idle(long timeout);
276 asmlinkage void schedule(void);
277 extern void schedule_preempt_disabled(void);
278 asmlinkage void preempt_schedule_irq(void);
279 
280 extern int __must_check io_schedule_prepare(void);
281 extern void io_schedule_finish(int token);
282 extern long io_schedule_timeout(long timeout);
283 extern void io_schedule(void);
284 
285 /**
286  * struct prev_cputime - snapshot of system and user cputime
287  * @utime: time spent in user mode
288  * @stime: time spent in system mode
289  * @lock: protects the above two fields
290  *
291  * Stores previous user/system time values such that we can guarantee
292  * monotonicity.
293  */
294 struct prev_cputime {
295 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
296 	u64				utime;
297 	u64				stime;
298 	raw_spinlock_t			lock;
299 #endif
300 };
301 
302 enum vtime_state {
303 	/* Task is sleeping or running in a CPU with VTIME inactive: */
304 	VTIME_INACTIVE = 0,
305 	/* Task is idle */
306 	VTIME_IDLE,
307 	/* Task runs in kernelspace in a CPU with VTIME active: */
308 	VTIME_SYS,
309 	/* Task runs in userspace in a CPU with VTIME active: */
310 	VTIME_USER,
311 	/* Task runs as guests in a CPU with VTIME active: */
312 	VTIME_GUEST,
313 };
314 
315 struct vtime {
316 	seqcount_t		seqcount;
317 	unsigned long long	starttime;
318 	enum vtime_state	state;
319 	unsigned int		cpu;
320 	u64			utime;
321 	u64			stime;
322 	u64			gtime;
323 };
324 
325 /*
326  * Utilization clamp constraints.
327  * @UCLAMP_MIN:	Minimum utilization
328  * @UCLAMP_MAX:	Maximum utilization
329  * @UCLAMP_CNT:	Utilization clamp constraints count
330  */
331 enum uclamp_id {
332 	UCLAMP_MIN = 0,
333 	UCLAMP_MAX,
334 	UCLAMP_CNT
335 };
336 
337 #ifdef CONFIG_SMP
338 extern struct root_domain def_root_domain;
339 extern struct mutex sched_domains_mutex;
340 #endif
341 
342 struct sched_info {
343 #ifdef CONFIG_SCHED_INFO
344 	/* Cumulative counters: */
345 
346 	/* # of times we have run on this CPU: */
347 	unsigned long			pcount;
348 
349 	/* Time spent waiting on a runqueue: */
350 	unsigned long long		run_delay;
351 
352 	/* Timestamps: */
353 
354 	/* When did we last run on a CPU? */
355 	unsigned long long		last_arrival;
356 
357 	/* When were we last queued to run? */
358 	unsigned long long		last_queued;
359 
360 #endif /* CONFIG_SCHED_INFO */
361 };
362 
363 /*
364  * Integer metrics need fixed point arithmetic, e.g., sched/fair
365  * has a few: load, load_avg, util_avg, freq, and capacity.
366  *
367  * We define a basic fixed point arithmetic range, and then formalize
368  * all these metrics based on that basic range.
369  */
370 # define SCHED_FIXEDPOINT_SHIFT		10
371 # define SCHED_FIXEDPOINT_SCALE		(1L << SCHED_FIXEDPOINT_SHIFT)
372 
373 /* Increase resolution of cpu_capacity calculations */
374 # define SCHED_CAPACITY_SHIFT		SCHED_FIXEDPOINT_SHIFT
375 # define SCHED_CAPACITY_SCALE		(1L << SCHED_CAPACITY_SHIFT)
376 
377 struct load_weight {
378 	unsigned long			weight;
379 	u32				inv_weight;
380 };
381 
382 /**
383  * struct util_est - Estimation utilization of FAIR tasks
384  * @enqueued: instantaneous estimated utilization of a task/cpu
385  * @ewma:     the Exponential Weighted Moving Average (EWMA)
386  *            utilization of a task
387  *
388  * Support data structure to track an Exponential Weighted Moving Average
389  * (EWMA) of a FAIR task's utilization. New samples are added to the moving
390  * average each time a task completes an activation. Sample's weight is chosen
391  * so that the EWMA will be relatively insensitive to transient changes to the
392  * task's workload.
393  *
394  * The enqueued attribute has a slightly different meaning for tasks and cpus:
395  * - task:   the task's util_avg at last task dequeue time
396  * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU
397  * Thus, the util_est.enqueued of a task represents the contribution on the
398  * estimated utilization of the CPU where that task is currently enqueued.
399  *
400  * Only for tasks we track a moving average of the past instantaneous
401  * estimated utilization. This allows to absorb sporadic drops in utilization
402  * of an otherwise almost periodic task.
403  *
404  * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg
405  * updates. When a task is dequeued, its util_est should not be updated if its
406  * util_avg has not been updated in the meantime.
407  * This information is mapped into the MSB bit of util_est.enqueued at dequeue
408  * time. Since max value of util_est.enqueued for a task is 1024 (PELT util_avg
409  * for a task) it is safe to use MSB.
410  */
411 struct util_est {
412 	unsigned int			enqueued;
413 	unsigned int			ewma;
414 #define UTIL_EST_WEIGHT_SHIFT		2
415 #define UTIL_AVG_UNCHANGED		0x80000000
416 } __attribute__((__aligned__(sizeof(u64))));
417 
418 /*
419  * The load/runnable/util_avg accumulates an infinite geometric series
420  * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c).
421  *
422  * [load_avg definition]
423  *
424  *   load_avg = runnable% * scale_load_down(load)
425  *
426  * [runnable_avg definition]
427  *
428  *   runnable_avg = runnable% * SCHED_CAPACITY_SCALE
429  *
430  * [util_avg definition]
431  *
432  *   util_avg = running% * SCHED_CAPACITY_SCALE
433  *
434  * where runnable% is the time ratio that a sched_entity is runnable and
435  * running% the time ratio that a sched_entity is running.
436  *
437  * For cfs_rq, they are the aggregated values of all runnable and blocked
438  * sched_entities.
439  *
440  * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU
441  * capacity scaling. The scaling is done through the rq_clock_pelt that is used
442  * for computing those signals (see update_rq_clock_pelt())
443  *
444  * N.B., the above ratios (runnable% and running%) themselves are in the
445  * range of [0, 1]. To do fixed point arithmetics, we therefore scale them
446  * to as large a range as necessary. This is for example reflected by
447  * util_avg's SCHED_CAPACITY_SCALE.
448  *
449  * [Overflow issue]
450  *
451  * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
452  * with the highest load (=88761), always runnable on a single cfs_rq,
453  * and should not overflow as the number already hits PID_MAX_LIMIT.
454  *
455  * For all other cases (including 32-bit kernels), struct load_weight's
456  * weight will overflow first before we do, because:
457  *
458  *    Max(load_avg) <= Max(load.weight)
459  *
460  * Then it is the load_weight's responsibility to consider overflow
461  * issues.
462  */
463 struct sched_avg {
464 	u64				last_update_time;
465 	u64				load_sum;
466 	u64				runnable_sum;
467 	u32				util_sum;
468 	u32				period_contrib;
469 	unsigned long			load_avg;
470 	unsigned long			runnable_avg;
471 	unsigned long			util_avg;
472 	struct util_est			util_est;
473 } ____cacheline_aligned;
474 
475 struct sched_statistics {
476 #ifdef CONFIG_SCHEDSTATS
477 	u64				wait_start;
478 	u64				wait_max;
479 	u64				wait_count;
480 	u64				wait_sum;
481 	u64				iowait_count;
482 	u64				iowait_sum;
483 
484 	u64				sleep_start;
485 	u64				sleep_max;
486 	s64				sum_sleep_runtime;
487 
488 	u64				block_start;
489 	u64				block_max;
490 	u64				exec_max;
491 	u64				slice_max;
492 
493 	u64				nr_migrations_cold;
494 	u64				nr_failed_migrations_affine;
495 	u64				nr_failed_migrations_running;
496 	u64				nr_failed_migrations_hot;
497 	u64				nr_forced_migrations;
498 
499 	u64				nr_wakeups;
500 	u64				nr_wakeups_sync;
501 	u64				nr_wakeups_migrate;
502 	u64				nr_wakeups_local;
503 	u64				nr_wakeups_remote;
504 	u64				nr_wakeups_affine;
505 	u64				nr_wakeups_affine_attempts;
506 	u64				nr_wakeups_passive;
507 	u64				nr_wakeups_idle;
508 #endif
509 };
510 
511 struct sched_entity {
512 	/* For load-balancing: */
513 	struct load_weight		load;
514 	struct rb_node			run_node;
515 	struct list_head		group_node;
516 	unsigned int			on_rq;
517 
518 	u64				exec_start;
519 	u64				sum_exec_runtime;
520 	u64				vruntime;
521 	u64				prev_sum_exec_runtime;
522 
523 	u64				nr_migrations;
524 
525 	struct sched_statistics		statistics;
526 
527 #ifdef CONFIG_FAIR_GROUP_SCHED
528 	int				depth;
529 	struct sched_entity		*parent;
530 	/* rq on which this entity is (to be) queued: */
531 	struct cfs_rq			*cfs_rq;
532 	/* rq "owned" by this entity/group: */
533 	struct cfs_rq			*my_q;
534 	/* cached value of my_q->h_nr_running */
535 	unsigned long			runnable_weight;
536 #endif
537 
538 #ifdef CONFIG_SMP
539 	/*
540 	 * Per entity load average tracking.
541 	 *
542 	 * Put into separate cache line so it does not
543 	 * collide with read-mostly values above.
544 	 */
545 	struct sched_avg		avg;
546 #endif
547 };
548 
549 #ifdef CONFIG_SCHED_WALT
550 extern void sched_exit(struct task_struct *p);
551 extern int sched_set_init_task_load(struct task_struct *p, int init_load_pct);
552 extern u32 sched_get_init_task_load(struct task_struct *p);
553 extern void free_task_load_ptrs(struct task_struct *p);
554 #define RAVG_HIST_SIZE_MAX  5
555 struct ravg {
556 	/*
557 	 * 'mark_start' marks the beginning of an event (task waking up, task
558 	 * starting to execute, task being preempted) within a window
559 	 *
560 	 * 'sum' represents how runnable a task has been within current
561 	 * window. It incorporates both running time and wait time and is
562 	 * frequency scaled.
563 	 *
564 	 * 'sum_history' keeps track of history of 'sum' seen over previous
565 	 * RAVG_HIST_SIZE windows. Windows where task was entirely sleeping are
566 	 * ignored.
567 	 *
568 	 * 'demand' represents maximum sum seen over previous
569 	 * sysctl_sched_ravg_hist_size windows. 'demand' could drive frequency
570 	 * demand for tasks.
571 	 *
572 	 * 'curr_window_cpu' represents task's contribution to cpu busy time on
573 	 * various CPUs in the current window
574 	 *
575 	 * 'prev_window_cpu' represents task's contribution to cpu busy time on
576 	 * various CPUs in the previous window
577 	 *
578 	 * 'curr_window' represents the sum of all entries in curr_window_cpu
579 	 *
580 	 * 'prev_window' represents the sum of all entries in prev_window_cpu
581 	 *
582 	 */
583 	u64 mark_start;
584 	u32 sum, demand;
585 	u32 sum_history[RAVG_HIST_SIZE_MAX];
586 	u32 *curr_window_cpu, *prev_window_cpu;
587 	u32 curr_window, prev_window;
588 	u16 active_windows;
589 	u16 demand_scaled;
590 };
591 #else
sched_exit(struct task_struct * p)592 static inline void sched_exit(struct task_struct *p) { }
free_task_load_ptrs(struct task_struct * p)593 static inline void free_task_load_ptrs(struct task_struct *p) { }
594 #endif /* CONFIG_SCHED_WALT */
595 
596 struct sched_rt_entity {
597 	struct list_head		run_list;
598 	unsigned long			timeout;
599 	unsigned long			watchdog_stamp;
600 	unsigned int			time_slice;
601 	unsigned short			on_rq;
602 	unsigned short			on_list;
603 
604 	struct sched_rt_entity		*back;
605 #ifdef CONFIG_RT_GROUP_SCHED
606 	struct sched_rt_entity		*parent;
607 	/* rq on which this entity is (to be) queued: */
608 	struct rt_rq			*rt_rq;
609 	/* rq "owned" by this entity/group: */
610 	struct rt_rq			*my_q;
611 #endif
612 } __randomize_layout;
613 
614 struct sched_dl_entity {
615 	struct rb_node			rb_node;
616 
617 	/*
618 	 * Original scheduling parameters. Copied here from sched_attr
619 	 * during sched_setattr(), they will remain the same until
620 	 * the next sched_setattr().
621 	 */
622 	u64				dl_runtime;	/* Maximum runtime for each instance	*/
623 	u64				dl_deadline;	/* Relative deadline of each instance	*/
624 	u64				dl_period;	/* Separation of two instances (period) */
625 	u64				dl_bw;		/* dl_runtime / dl_period		*/
626 	u64				dl_density;	/* dl_runtime / dl_deadline		*/
627 
628 	/*
629 	 * Actual scheduling parameters. Initialized with the values above,
630 	 * they are continuously updated during task execution. Note that
631 	 * the remaining runtime could be < 0 in case we are in overrun.
632 	 */
633 	s64				runtime;	/* Remaining runtime for this instance	*/
634 	u64				deadline;	/* Absolute deadline for this instance	*/
635 	unsigned int			flags;		/* Specifying the scheduler behaviour	*/
636 
637 	/*
638 	 * Some bool flags:
639 	 *
640 	 * @dl_throttled tells if we exhausted the runtime. If so, the
641 	 * task has to wait for a replenishment to be performed at the
642 	 * next firing of dl_timer.
643 	 *
644 	 * @dl_boosted tells if we are boosted due to DI. If so we are
645 	 * outside bandwidth enforcement mechanism (but only until we
646 	 * exit the critical section);
647 	 *
648 	 * @dl_yielded tells if task gave up the CPU before consuming
649 	 * all its available runtime during the last job.
650 	 *
651 	 * @dl_non_contending tells if the task is inactive while still
652 	 * contributing to the active utilization. In other words, it
653 	 * indicates if the inactive timer has been armed and its handler
654 	 * has not been executed yet. This flag is useful to avoid race
655 	 * conditions between the inactive timer handler and the wakeup
656 	 * code.
657 	 *
658 	 * @dl_overrun tells if the task asked to be informed about runtime
659 	 * overruns.
660 	 */
661 	unsigned int			dl_throttled      : 1;
662 	unsigned int			dl_yielded        : 1;
663 	unsigned int			dl_non_contending : 1;
664 	unsigned int			dl_overrun	  : 1;
665 
666 	/*
667 	 * Bandwidth enforcement timer. Each -deadline task has its
668 	 * own bandwidth to be enforced, thus we need one timer per task.
669 	 */
670 	struct hrtimer			dl_timer;
671 
672 	/*
673 	 * Inactive timer, responsible for decreasing the active utilization
674 	 * at the "0-lag time". When a -deadline task blocks, it contributes
675 	 * to GRUB's active utilization until the "0-lag time", hence a
676 	 * timer is needed to decrease the active utilization at the correct
677 	 * time.
678 	 */
679 	struct hrtimer inactive_timer;
680 
681 #ifdef CONFIG_RT_MUTEXES
682 	/*
683 	 * Priority Inheritance. When a DEADLINE scheduling entity is boosted
684 	 * pi_se points to the donor, otherwise points to the dl_se it belongs
685 	 * to (the original one/itself).
686 	 */
687 	struct sched_dl_entity *pi_se;
688 #endif
689 };
690 
691 #ifdef CONFIG_UCLAMP_TASK
692 /* Number of utilization clamp buckets (shorter alias) */
693 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT
694 
695 /*
696  * Utilization clamp for a scheduling entity
697  * @value:		clamp value "assigned" to a se
698  * @bucket_id:		bucket index corresponding to the "assigned" value
699  * @active:		the se is currently refcounted in a rq's bucket
700  * @user_defined:	the requested clamp value comes from user-space
701  *
702  * The bucket_id is the index of the clamp bucket matching the clamp value
703  * which is pre-computed and stored to avoid expensive integer divisions from
704  * the fast path.
705  *
706  * The active bit is set whenever a task has got an "effective" value assigned,
707  * which can be different from the clamp value "requested" from user-space.
708  * This allows to know a task is refcounted in the rq's bucket corresponding
709  * to the "effective" bucket_id.
710  *
711  * The user_defined bit is set whenever a task has got a task-specific clamp
712  * value requested from userspace, i.e. the system defaults apply to this task
713  * just as a restriction. This allows to relax default clamps when a less
714  * restrictive task-specific value has been requested, thus allowing to
715  * implement a "nice" semantic. For example, a task running with a 20%
716  * default boost can still drop its own boosting to 0%.
717  */
718 struct uclamp_se {
719 	unsigned int value		: bits_per(SCHED_CAPACITY_SCALE);
720 	unsigned int bucket_id		: bits_per(UCLAMP_BUCKETS);
721 	unsigned int active		: 1;
722 	unsigned int user_defined	: 1;
723 };
724 #endif /* CONFIG_UCLAMP_TASK */
725 
726 union rcu_special {
727 	struct {
728 		u8			blocked;
729 		u8			need_qs;
730 		u8			exp_hint; /* Hint for performance. */
731 		u8			need_mb; /* Readers need smp_mb(). */
732 	} b; /* Bits. */
733 	u32 s; /* Set of bits. */
734 };
735 
736 enum perf_event_task_context {
737 	perf_invalid_context = -1,
738 	perf_hw_context = 0,
739 	perf_sw_context,
740 	perf_nr_task_contexts,
741 };
742 
743 struct wake_q_node {
744 	struct wake_q_node *next;
745 };
746 
747 struct task_struct {
748 #ifdef CONFIG_THREAD_INFO_IN_TASK
749 	/*
750 	 * For reasons of header soup (see current_thread_info()), this
751 	 * must be the first element of task_struct.
752 	 */
753 	struct thread_info		thread_info;
754 #endif
755 	/* -1 unrunnable, 0 runnable, >0 stopped: */
756 	volatile long			state;
757 
758 	/*
759 	 * This begins the randomizable portion of task_struct. Only
760 	 * scheduling-critical items should be added above here.
761 	 */
762 	randomized_struct_fields_start
763 
764 	void				*stack;
765 	refcount_t			usage;
766 	/* Per task flags (PF_*), defined further below: */
767 	unsigned int			flags;
768 	unsigned int			ptrace;
769 
770 #ifdef CONFIG_SMP
771 	int				on_cpu;
772 	struct __call_single_node	wake_entry;
773 #ifdef CONFIG_THREAD_INFO_IN_TASK
774 	/* Current CPU: */
775 	unsigned int			cpu;
776 #endif
777 	unsigned int			wakee_flips;
778 	unsigned long			wakee_flip_decay_ts;
779 	struct task_struct		*last_wakee;
780 
781 	/*
782 	 * recent_used_cpu is initially set as the last CPU used by a task
783 	 * that wakes affine another task. Waker/wakee relationships can
784 	 * push tasks around a CPU where each wakeup moves to the next one.
785 	 * Tracking a recently used CPU allows a quick search for a recently
786 	 * used CPU that may be idle.
787 	 */
788 	int				recent_used_cpu;
789 	int				wake_cpu;
790 #endif
791 	int				on_rq;
792 
793 	int				prio;
794 	int				static_prio;
795 	int				normal_prio;
796 	unsigned int			rt_priority;
797 
798 	const struct sched_class	*sched_class;
799 	struct sched_entity		se;
800 	struct sched_rt_entity		rt;
801 #ifdef CONFIG_SCHED_WALT
802 	struct ravg ravg;
803 	/*
804 	 * 'init_load_pct' represents the initial task load assigned to children
805 	 * of this task
806 	 */
807 	u32 init_load_pct;
808 	u64 last_sleep_ts;
809 #endif
810 
811 #ifdef CONFIG_SCHED_RTG
812 	int rtg_depth;
813 	struct related_thread_group	*grp;
814 	struct list_head		grp_list;
815 #endif
816 
817 #ifdef CONFIG_CGROUP_SCHED
818 	struct task_group		*sched_task_group;
819 #endif
820 	struct sched_dl_entity		dl;
821 
822 #ifdef CONFIG_UCLAMP_TASK
823 	/*
824 	 * Clamp values requested for a scheduling entity.
825 	 * Must be updated with task_rq_lock() held.
826 	 */
827 	struct uclamp_se		uclamp_req[UCLAMP_CNT];
828 	/*
829 	 * Effective clamp values used for a scheduling entity.
830 	 * Must be updated with task_rq_lock() held.
831 	 */
832 	struct uclamp_se		uclamp[UCLAMP_CNT];
833 #endif
834 
835 #ifdef CONFIG_PREEMPT_NOTIFIERS
836 	/* List of struct preempt_notifier: */
837 	struct hlist_head		preempt_notifiers;
838 #endif
839 
840 #ifdef CONFIG_BLK_DEV_IO_TRACE
841 	unsigned int			btrace_seq;
842 #endif
843 
844 	unsigned int			policy;
845 	int				nr_cpus_allowed;
846 	const cpumask_t			*cpus_ptr;
847 	cpumask_t			cpus_mask;
848 
849 #ifdef CONFIG_PREEMPT_RCU
850 	int				rcu_read_lock_nesting;
851 	union rcu_special		rcu_read_unlock_special;
852 	struct list_head		rcu_node_entry;
853 	struct rcu_node			*rcu_blocked_node;
854 #endif /* #ifdef CONFIG_PREEMPT_RCU */
855 
856 #ifdef CONFIG_TASKS_RCU
857 	unsigned long			rcu_tasks_nvcsw;
858 	u8				rcu_tasks_holdout;
859 	u8				rcu_tasks_idx;
860 	int				rcu_tasks_idle_cpu;
861 	struct list_head		rcu_tasks_holdout_list;
862 #endif /* #ifdef CONFIG_TASKS_RCU */
863 
864 #ifdef CONFIG_TASKS_TRACE_RCU
865 	int				trc_reader_nesting;
866 	int				trc_ipi_to_cpu;
867 	union rcu_special		trc_reader_special;
868 	bool				trc_reader_checked;
869 	struct list_head		trc_holdout_list;
870 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
871 
872 	struct sched_info		sched_info;
873 
874 	struct list_head		tasks;
875 #ifdef CONFIG_SMP
876 	struct plist_node		pushable_tasks;
877 	struct rb_node			pushable_dl_tasks;
878 #endif
879 
880 	struct mm_struct		*mm;
881 	struct mm_struct		*active_mm;
882 
883 	/* Per-thread vma caching: */
884 	struct vmacache			vmacache;
885 
886 #ifdef SPLIT_RSS_COUNTING
887 	struct task_rss_stat		rss_stat;
888 #endif
889 	int				exit_state;
890 	int				exit_code;
891 	int				exit_signal;
892 	/* The signal sent when the parent dies: */
893 	int				pdeath_signal;
894 	/* JOBCTL_*, siglock protected: */
895 	unsigned long			jobctl;
896 
897 	/* Used for emulating ABI behavior of previous Linux versions: */
898 	unsigned int			personality;
899 
900 	/* Scheduler bits, serialized by scheduler locks: */
901 	unsigned			sched_reset_on_fork:1;
902 	unsigned			sched_contributes_to_load:1;
903 	unsigned			sched_migrated:1;
904 #ifdef CONFIG_PSI
905 	unsigned			sched_psi_wake_requeue:1;
906 #endif
907 
908 	/* Force alignment to the next boundary: */
909 	unsigned			:0;
910 
911 	/* Unserialized, strictly 'current' */
912 
913 	/*
914 	 * This field must not be in the scheduler word above due to wakelist
915 	 * queueing no longer being serialized by p->on_cpu. However:
916 	 *
917 	 * p->XXX = X;			ttwu()
918 	 * schedule()			  if (p->on_rq && ..) // false
919 	 *   smp_mb__after_spinlock();	  if (smp_load_acquire(&p->on_cpu) && //true
920 	 *   deactivate_task()		      ttwu_queue_wakelist())
921 	 *     p->on_rq = 0;			p->sched_remote_wakeup = Y;
922 	 *
923 	 * guarantees all stores of 'current' are visible before
924 	 * ->sched_remote_wakeup gets used, so it can be in this word.
925 	 */
926 	unsigned			sched_remote_wakeup:1;
927 
928 	/* Bit to tell LSMs we're in execve(): */
929 	unsigned			in_execve:1;
930 	unsigned			in_iowait:1;
931 #ifndef TIF_RESTORE_SIGMASK
932 	unsigned			restore_sigmask:1;
933 #endif
934 #ifdef CONFIG_MEMCG
935 	unsigned			in_user_fault:1;
936 #endif
937 #ifdef CONFIG_COMPAT_BRK
938 	unsigned			brk_randomized:1;
939 #endif
940 #ifdef CONFIG_CGROUPS
941 	/* disallow userland-initiated cgroup migration */
942 	unsigned			no_cgroup_migration:1;
943 	/* task is frozen/stopped (used by the cgroup freezer) */
944 	unsigned			frozen:1;
945 #endif
946 #ifdef CONFIG_BLK_CGROUP
947 	unsigned			use_memdelay:1;
948 #endif
949 #ifdef CONFIG_PSI
950 	/* Stalled due to lack of memory */
951 	unsigned			in_memstall:1;
952 #endif
953 
954 	unsigned long			atomic_flags; /* Flags requiring atomic access. */
955 
956 	struct restart_block		restart_block;
957 
958 	pid_t				pid;
959 	pid_t				tgid;
960 
961 #ifdef CONFIG_STACKPROTECTOR
962 	/* Canary value for the -fstack-protector GCC feature: */
963 	unsigned long			stack_canary;
964 #endif
965 	/*
966 	 * Pointers to the (original) parent process, youngest child, younger sibling,
967 	 * older sibling, respectively.  (p->father can be replaced with
968 	 * p->real_parent->pid)
969 	 */
970 
971 	/* Real parent process: */
972 	struct task_struct __rcu	*real_parent;
973 
974 	/* Recipient of SIGCHLD, wait4() reports: */
975 	struct task_struct __rcu	*parent;
976 
977 	/*
978 	 * Children/sibling form the list of natural children:
979 	 */
980 	struct list_head		children;
981 	struct list_head		sibling;
982 	struct task_struct		*group_leader;
983 
984 	/*
985 	 * 'ptraced' is the list of tasks this task is using ptrace() on.
986 	 *
987 	 * This includes both natural children and PTRACE_ATTACH targets.
988 	 * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
989 	 */
990 	struct list_head		ptraced;
991 	struct list_head		ptrace_entry;
992 
993 	/* PID/PID hash table linkage. */
994 	struct pid			*thread_pid;
995 	struct hlist_node		pid_links[PIDTYPE_MAX];
996 	struct list_head		thread_group;
997 	struct list_head		thread_node;
998 
999 	struct completion		*vfork_done;
1000 
1001 	/* CLONE_CHILD_SETTID: */
1002 	int __user			*set_child_tid;
1003 
1004 	/* CLONE_CHILD_CLEARTID: */
1005 	int __user			*clear_child_tid;
1006 
1007 	u64				utime;
1008 	u64				stime;
1009 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
1010 	u64				utimescaled;
1011 	u64				stimescaled;
1012 #endif
1013 	u64				gtime;
1014 	struct prev_cputime		prev_cputime;
1015 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1016 	struct vtime			vtime;
1017 #endif
1018 
1019 #ifdef CONFIG_NO_HZ_FULL
1020 	atomic_t			tick_dep_mask;
1021 #endif
1022 	/* Context switch counts: */
1023 	unsigned long			nvcsw;
1024 	unsigned long			nivcsw;
1025 
1026 	/* Monotonic time in nsecs: */
1027 	u64				start_time;
1028 
1029 	/* Boot based time in nsecs: */
1030 	u64				start_boottime;
1031 
1032 	/* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
1033 	unsigned long			min_flt;
1034 	unsigned long			maj_flt;
1035 
1036 	/* Empty if CONFIG_POSIX_CPUTIMERS=n */
1037 	struct posix_cputimers		posix_cputimers;
1038 
1039 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK
1040 	struct posix_cputimers_work	posix_cputimers_work;
1041 #endif
1042 
1043 	/* Process credentials: */
1044 
1045 	/* Tracer's credentials at attach: */
1046 	const struct cred __rcu		*ptracer_cred;
1047 
1048 	/* Objective and real subjective task credentials (COW): */
1049 	const struct cred __rcu		*real_cred;
1050 
1051 	/* Effective (overridable) subjective task credentials (COW): */
1052 	const struct cred __rcu		*cred;
1053 
1054 #ifdef CONFIG_KEYS
1055 	/* Cached requested key. */
1056 	struct key			*cached_requested_key;
1057 #endif
1058 
1059 	/*
1060 	 * executable name, excluding path.
1061 	 *
1062 	 * - normally initialized setup_new_exec()
1063 	 * - access it with [gs]et_task_comm()
1064 	 * - lock it with task_lock()
1065 	 */
1066 	char				comm[TASK_COMM_LEN];
1067 
1068 	struct nameidata		*nameidata;
1069 
1070 #ifdef CONFIG_SYSVIPC
1071 	struct sysv_sem			sysvsem;
1072 	struct sysv_shm			sysvshm;
1073 #endif
1074 #ifdef CONFIG_DETECT_HUNG_TASK
1075 	unsigned long			last_switch_count;
1076 	unsigned long			last_switch_time;
1077 #endif
1078 	/* Filesystem information: */
1079 	struct fs_struct		*fs;
1080 
1081 	/* Open file information: */
1082 	struct files_struct		*files;
1083 
1084 #ifdef CONFIG_IO_URING
1085 	struct io_uring_task		*io_uring;
1086 #endif
1087 
1088 	/* Namespaces: */
1089 	struct nsproxy			*nsproxy;
1090 
1091 	/* Signal handlers: */
1092 	struct signal_struct		*signal;
1093 	struct sighand_struct __rcu		*sighand;
1094 	sigset_t			blocked;
1095 	sigset_t			real_blocked;
1096 	/* Restored if set_restore_sigmask() was used: */
1097 	sigset_t			saved_sigmask;
1098 	struct sigpending		pending;
1099 	unsigned long			sas_ss_sp;
1100 	size_t				sas_ss_size;
1101 	unsigned int			sas_ss_flags;
1102 
1103 	struct callback_head		*task_works;
1104 
1105 #ifdef CONFIG_AUDIT
1106 #ifdef CONFIG_AUDITSYSCALL
1107 	struct audit_context		*audit_context;
1108 #endif
1109 	kuid_t				loginuid;
1110 	unsigned int			sessionid;
1111 #endif
1112 	struct seccomp			seccomp;
1113 
1114 	/* Thread group tracking: */
1115 	u64				parent_exec_id;
1116 	u64				self_exec_id;
1117 
1118 	/* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
1119 	spinlock_t			alloc_lock;
1120 
1121 	/* Protection of the PI data structures: */
1122 	raw_spinlock_t			pi_lock;
1123 
1124 	struct wake_q_node		wake_q;
1125 
1126 #ifdef CONFIG_RT_MUTEXES
1127 	/* PI waiters blocked on a rt_mutex held by this task: */
1128 	struct rb_root_cached		pi_waiters;
1129 	/* Updated under owner's pi_lock and rq lock */
1130 	struct task_struct		*pi_top_task;
1131 	/* Deadlock detection and priority inheritance handling: */
1132 	struct rt_mutex_waiter		*pi_blocked_on;
1133 #endif
1134 
1135 #ifdef CONFIG_DEBUG_MUTEXES
1136 	/* Mutex deadlock detection: */
1137 	struct mutex_waiter		*blocked_on;
1138 #endif
1139 
1140 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1141 	int				non_block_count;
1142 #endif
1143 
1144 #ifdef CONFIG_TRACE_IRQFLAGS
1145 	struct irqtrace_events		irqtrace;
1146 	unsigned int			hardirq_threaded;
1147 	u64				hardirq_chain_key;
1148 	int				softirqs_enabled;
1149 	int				softirq_context;
1150 	int				irq_config;
1151 #endif
1152 
1153 #ifdef CONFIG_LOCKDEP
1154 # define MAX_LOCK_DEPTH			48UL
1155 	u64				curr_chain_key;
1156 	int				lockdep_depth;
1157 	unsigned int			lockdep_recursion;
1158 	struct held_lock		held_locks[MAX_LOCK_DEPTH];
1159 #endif
1160 
1161 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP)
1162 	unsigned int			in_ubsan;
1163 #endif
1164 
1165 	/* Journalling filesystem info: */
1166 	void				*journal_info;
1167 
1168 	/* Stacked block device info: */
1169 	struct bio_list			*bio_list;
1170 
1171 #ifdef CONFIG_BLOCK
1172 	/* Stack plugging: */
1173 	struct blk_plug			*plug;
1174 #endif
1175 
1176 	/* VM state: */
1177 	struct reclaim_state		*reclaim_state;
1178 
1179 	struct backing_dev_info		*backing_dev_info;
1180 
1181 	struct io_context		*io_context;
1182 
1183 #ifdef CONFIG_COMPACTION
1184 	struct capture_control		*capture_control;
1185 #endif
1186 	/* Ptrace state: */
1187 	unsigned long			ptrace_message;
1188 	kernel_siginfo_t		*last_siginfo;
1189 
1190 	struct task_io_accounting	ioac;
1191 #ifdef CONFIG_PSI
1192 	/* Pressure stall state */
1193 	unsigned int			psi_flags;
1194 #endif
1195 #ifdef CONFIG_TASK_XACCT
1196 	/* Accumulated RSS usage: */
1197 	u64				acct_rss_mem1;
1198 	/* Accumulated virtual memory usage: */
1199 	u64				acct_vm_mem1;
1200 	/* stime + utime since last update: */
1201 	u64				acct_timexpd;
1202 #endif
1203 #ifdef CONFIG_CPUSETS
1204 	/* Protected by ->alloc_lock: */
1205 	nodemask_t			mems_allowed;
1206 	/* Seqence number to catch updates: */
1207 	seqcount_spinlock_t		mems_allowed_seq;
1208 	int				cpuset_mem_spread_rotor;
1209 	int				cpuset_slab_spread_rotor;
1210 #endif
1211 #ifdef CONFIG_CGROUPS
1212 	/* Control Group info protected by css_set_lock: */
1213 	struct css_set __rcu		*cgroups;
1214 	/* cg_list protected by css_set_lock and tsk->alloc_lock: */
1215 	struct list_head		cg_list;
1216 #endif
1217 #ifdef CONFIG_X86_CPU_RESCTRL
1218 	u32				closid;
1219 	u32				rmid;
1220 #endif
1221 #ifdef CONFIG_FUTEX
1222 	struct robust_list_head __user	*robust_list;
1223 #ifdef CONFIG_COMPAT
1224 	struct compat_robust_list_head __user *compat_robust_list;
1225 #endif
1226 	struct list_head		pi_state_list;
1227 	struct futex_pi_state		*pi_state_cache;
1228 	struct mutex			futex_exit_mutex;
1229 	unsigned int			futex_state;
1230 #endif
1231 #ifdef CONFIG_PERF_EVENTS
1232 	struct perf_event_context	*perf_event_ctxp[perf_nr_task_contexts];
1233 	struct mutex			perf_event_mutex;
1234 	struct list_head		perf_event_list;
1235 #endif
1236 #ifdef CONFIG_DEBUG_PREEMPT
1237 	unsigned long			preempt_disable_ip;
1238 #endif
1239 #ifdef CONFIG_NUMA
1240 	/* Protected by alloc_lock: */
1241 	struct mempolicy		*mempolicy;
1242 	short				il_prev;
1243 	short				pref_node_fork;
1244 #endif
1245 #ifdef CONFIG_NUMA_BALANCING
1246 	int				numa_scan_seq;
1247 	unsigned int			numa_scan_period;
1248 	unsigned int			numa_scan_period_max;
1249 	int				numa_preferred_nid;
1250 	unsigned long			numa_migrate_retry;
1251 	/* Migration stamp: */
1252 	u64				node_stamp;
1253 	u64				last_task_numa_placement;
1254 	u64				last_sum_exec_runtime;
1255 	struct callback_head		numa_work;
1256 
1257 	/*
1258 	 * This pointer is only modified for current in syscall and
1259 	 * pagefault context (and for tasks being destroyed), so it can be read
1260 	 * from any of the following contexts:
1261 	 *  - RCU read-side critical section
1262 	 *  - current->numa_group from everywhere
1263 	 *  - task's runqueue locked, task not running
1264 	 */
1265 	struct numa_group __rcu		*numa_group;
1266 
1267 	/*
1268 	 * numa_faults is an array split into four regions:
1269 	 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1270 	 * in this precise order.
1271 	 *
1272 	 * faults_memory: Exponential decaying average of faults on a per-node
1273 	 * basis. Scheduling placement decisions are made based on these
1274 	 * counts. The values remain static for the duration of a PTE scan.
1275 	 * faults_cpu: Track the nodes the process was running on when a NUMA
1276 	 * hinting fault was incurred.
1277 	 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1278 	 * during the current scan window. When the scan completes, the counts
1279 	 * in faults_memory and faults_cpu decay and these values are copied.
1280 	 */
1281 	unsigned long			*numa_faults;
1282 	unsigned long			total_numa_faults;
1283 
1284 	/*
1285 	 * numa_faults_locality tracks if faults recorded during the last
1286 	 * scan window were remote/local or failed to migrate. The task scan
1287 	 * period is adapted based on the locality of the faults with different
1288 	 * weights depending on whether they were shared or private faults
1289 	 */
1290 	unsigned long			numa_faults_locality[3];
1291 
1292 	unsigned long			numa_pages_migrated;
1293 #endif /* CONFIG_NUMA_BALANCING */
1294 
1295 #ifdef CONFIG_RSEQ
1296 	struct rseq __user *rseq;
1297 	u32 rseq_sig;
1298 	/*
1299 	 * RmW on rseq_event_mask must be performed atomically
1300 	 * with respect to preemption.
1301 	 */
1302 	unsigned long rseq_event_mask;
1303 #endif
1304 
1305 	struct tlbflush_unmap_batch	tlb_ubc;
1306 
1307 	union {
1308 		refcount_t		rcu_users;
1309 		struct rcu_head		rcu;
1310 	};
1311 
1312 	/* Cache last used pipe for splice(): */
1313 	struct pipe_inode_info		*splice_pipe;
1314 
1315 	struct page_frag		task_frag;
1316 
1317 #ifdef CONFIG_TASK_DELAY_ACCT
1318 	struct task_delay_info		*delays;
1319 #endif
1320 
1321 #ifdef CONFIG_FAULT_INJECTION
1322 	int				make_it_fail;
1323 	unsigned int			fail_nth;
1324 #endif
1325 	/*
1326 	 * When (nr_dirtied >= nr_dirtied_pause), it's time to call
1327 	 * balance_dirty_pages() for a dirty throttling pause:
1328 	 */
1329 	int				nr_dirtied;
1330 	int				nr_dirtied_pause;
1331 	/* Start of a write-and-pause period: */
1332 	unsigned long			dirty_paused_when;
1333 
1334 #ifdef CONFIG_LATENCYTOP
1335 	int				latency_record_count;
1336 	struct latency_record		latency_record[LT_SAVECOUNT];
1337 #endif
1338 	/*
1339 	 * Time slack values; these are used to round up poll() and
1340 	 * select() etc timeout values. These are in nanoseconds.
1341 	 */
1342 	u64				timer_slack_ns;
1343 	u64				default_timer_slack_ns;
1344 
1345 #ifdef CONFIG_KASAN
1346 	unsigned int			kasan_depth;
1347 #endif
1348 
1349 #ifdef CONFIG_KCSAN
1350 	struct kcsan_ctx		kcsan_ctx;
1351 #ifdef CONFIG_TRACE_IRQFLAGS
1352 	struct irqtrace_events		kcsan_save_irqtrace;
1353 #endif
1354 #endif
1355 
1356 #if IS_ENABLED(CONFIG_KUNIT)
1357 	struct kunit			*kunit_test;
1358 #endif
1359 
1360 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1361 	/* Index of current stored address in ret_stack: */
1362 	int				curr_ret_stack;
1363 	int				curr_ret_depth;
1364 
1365 	/* Stack of return addresses for return function tracing: */
1366 	struct ftrace_ret_stack		*ret_stack;
1367 
1368 	/* Timestamp for last schedule: */
1369 	unsigned long long		ftrace_timestamp;
1370 
1371 	/*
1372 	 * Number of functions that haven't been traced
1373 	 * because of depth overrun:
1374 	 */
1375 	atomic_t			trace_overrun;
1376 
1377 	/* Pause tracing: */
1378 	atomic_t			tracing_graph_pause;
1379 #endif
1380 
1381 #ifdef CONFIG_TRACING
1382 	/* State flags for use by tracers: */
1383 	unsigned long			trace;
1384 
1385 	/* Bitmask and counter of trace recursion: */
1386 	unsigned long			trace_recursion;
1387 #endif /* CONFIG_TRACING */
1388 
1389 #ifdef CONFIG_KCOV
1390 	/* See kernel/kcov.c for more details. */
1391 
1392 	/* Coverage collection mode enabled for this task (0 if disabled): */
1393 	unsigned int			kcov_mode;
1394 
1395 	/* Size of the kcov_area: */
1396 	unsigned int			kcov_size;
1397 
1398 	/* Buffer for coverage collection: */
1399 	void				*kcov_area;
1400 
1401 	/* KCOV descriptor wired with this task or NULL: */
1402 	struct kcov			*kcov;
1403 
1404 	/* KCOV common handle for remote coverage collection: */
1405 	u64				kcov_handle;
1406 
1407 	/* KCOV sequence number: */
1408 	int				kcov_sequence;
1409 
1410 	/* Collect coverage from softirq context: */
1411 	unsigned int			kcov_softirq;
1412 #endif
1413 
1414 #ifdef CONFIG_MEMCG
1415 	struct mem_cgroup		*memcg_in_oom;
1416 	gfp_t				memcg_oom_gfp_mask;
1417 	int				memcg_oom_order;
1418 
1419 	/* Number of pages to reclaim on returning to userland: */
1420 	unsigned int			memcg_nr_pages_over_high;
1421 
1422 	/* Used by memcontrol for targeted memcg charge: */
1423 	struct mem_cgroup		*active_memcg;
1424 #endif
1425 
1426 #ifdef CONFIG_BLK_CGROUP
1427 	struct request_queue		*throttle_queue;
1428 #endif
1429 
1430 #ifdef CONFIG_UPROBES
1431 	struct uprobe_task		*utask;
1432 #endif
1433 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1434 	unsigned int			sequential_io;
1435 	unsigned int			sequential_io_avg;
1436 #endif
1437 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1438 	unsigned long			task_state_change;
1439 #endif
1440 	int				pagefault_disabled;
1441 #ifdef CONFIG_MMU
1442 	struct task_struct		*oom_reaper_list;
1443 #endif
1444 #ifdef CONFIG_VMAP_STACK
1445 	struct vm_struct		*stack_vm_area;
1446 #endif
1447 #ifdef CONFIG_THREAD_INFO_IN_TASK
1448 	/* A live task holds one reference: */
1449 	refcount_t			stack_refcount;
1450 #endif
1451 #ifdef CONFIG_LIVEPATCH
1452 	int patch_state;
1453 #endif
1454 #ifdef CONFIG_SECURITY
1455 	/* Used by LSM modules for access restriction: */
1456 	void				*security;
1457 #endif
1458 #ifdef CONFIG_BPF_SYSCALL
1459 	/* Used for BPF run context */
1460 	struct bpf_run_ctx		*bpf_ctx;
1461 #endif
1462 
1463 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK
1464 	unsigned long			lowest_stack;
1465 	unsigned long			prev_lowest_stack;
1466 #endif
1467 
1468 #ifdef CONFIG_X86_MCE
1469 	void __user			*mce_vaddr;
1470 	__u64				mce_kflags;
1471 	u64				mce_addr;
1472 	__u64				mce_ripv : 1,
1473 					mce_whole_page : 1,
1474 					__mce_reserved : 62;
1475 	struct callback_head		mce_kill_me;
1476 	int				mce_count;
1477 #endif
1478 
1479 #ifdef CONFIG_ACCESS_TOKENID
1480 	u64				token;
1481 	u64				ftoken;
1482 #endif
1483 	/*
1484 	 * New fields for task_struct should be added above here, so that
1485 	 * they are included in the randomized portion of task_struct.
1486 	 */
1487 	randomized_struct_fields_end
1488 
1489 	/* CPU-specific state of this task: */
1490 	struct thread_struct		thread;
1491 
1492 	/*
1493 	 * WARNING: on x86, 'thread_struct' contains a variable-sized
1494 	 * structure.  It *MUST* be at the end of 'task_struct'.
1495 	 *
1496 	 * Do not put anything below here!
1497 	 */
1498 };
1499 
task_pid(struct task_struct * task)1500 static inline struct pid *task_pid(struct task_struct *task)
1501 {
1502 	return task->thread_pid;
1503 }
1504 
1505 /*
1506  * the helpers to get the task's different pids as they are seen
1507  * from various namespaces
1508  *
1509  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1510  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1511  *                     current.
1512  * task_xid_nr_ns()  : id seen from the ns specified;
1513  *
1514  * see also pid_nr() etc in include/linux/pid.h
1515  */
1516 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns);
1517 
task_pid_nr(struct task_struct * tsk)1518 static inline pid_t task_pid_nr(struct task_struct *tsk)
1519 {
1520 	return tsk->pid;
1521 }
1522 
task_pid_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1523 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1524 {
1525 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1526 }
1527 
task_pid_vnr(struct task_struct * tsk)1528 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1529 {
1530 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1531 }
1532 
1533 
task_tgid_nr(struct task_struct * tsk)1534 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1535 {
1536 	return tsk->tgid;
1537 }
1538 
1539 /**
1540  * pid_alive - check that a task structure is not stale
1541  * @p: Task structure to be checked.
1542  *
1543  * Test if a process is not yet dead (at most zombie state)
1544  * If pid_alive fails, then pointers within the task structure
1545  * can be stale and must not be dereferenced.
1546  *
1547  * Return: 1 if the process is alive. 0 otherwise.
1548  */
pid_alive(const struct task_struct * p)1549 static inline int pid_alive(const struct task_struct *p)
1550 {
1551 	return p->thread_pid != NULL;
1552 }
1553 
task_pgrp_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1554 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1555 {
1556 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1557 }
1558 
task_pgrp_vnr(struct task_struct * tsk)1559 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1560 {
1561 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1562 }
1563 
1564 
task_session_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1565 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1566 {
1567 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1568 }
1569 
task_session_vnr(struct task_struct * tsk)1570 static inline pid_t task_session_vnr(struct task_struct *tsk)
1571 {
1572 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1573 }
1574 
task_tgid_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1575 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1576 {
1577 	return __task_pid_nr_ns(tsk, PIDTYPE_TGID, ns);
1578 }
1579 
task_tgid_vnr(struct task_struct * tsk)1580 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1581 {
1582 	return __task_pid_nr_ns(tsk, PIDTYPE_TGID, NULL);
1583 }
1584 
task_ppid_nr_ns(const struct task_struct * tsk,struct pid_namespace * ns)1585 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1586 {
1587 	pid_t pid = 0;
1588 
1589 	rcu_read_lock();
1590 	if (pid_alive(tsk))
1591 		pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1592 	rcu_read_unlock();
1593 
1594 	return pid;
1595 }
1596 
task_ppid_nr(const struct task_struct * tsk)1597 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1598 {
1599 	return task_ppid_nr_ns(tsk, &init_pid_ns);
1600 }
1601 
1602 /* Obsolete, do not use: */
task_pgrp_nr(struct task_struct * tsk)1603 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1604 {
1605 	return task_pgrp_nr_ns(tsk, &init_pid_ns);
1606 }
1607 
1608 #define TASK_REPORT_IDLE	(TASK_REPORT + 1)
1609 #define TASK_REPORT_MAX		(TASK_REPORT_IDLE << 1)
1610 
task_state_index(struct task_struct * tsk)1611 static inline unsigned int task_state_index(struct task_struct *tsk)
1612 {
1613 	unsigned int tsk_state = READ_ONCE(tsk->state);
1614 	unsigned int state = (tsk_state | tsk->exit_state) & TASK_REPORT;
1615 
1616 	BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX);
1617 
1618 	if (tsk_state == TASK_IDLE)
1619 		state = TASK_REPORT_IDLE;
1620 
1621 	return fls(state);
1622 }
1623 
task_index_to_char(unsigned int state)1624 static inline char task_index_to_char(unsigned int state)
1625 {
1626 	static const char state_char[] = "RSDTtXZPI";
1627 
1628 	BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1);
1629 
1630 	return state_char[state];
1631 }
1632 
task_state_to_char(struct task_struct * tsk)1633 static inline char task_state_to_char(struct task_struct *tsk)
1634 {
1635 	return task_index_to_char(task_state_index(tsk));
1636 }
1637 
1638 /**
1639  * is_global_init - check if a task structure is init. Since init
1640  * is free to have sub-threads we need to check tgid.
1641  * @tsk: Task structure to be checked.
1642  *
1643  * Check if a task structure is the first user space task the kernel created.
1644  *
1645  * Return: 1 if the task structure is init. 0 otherwise.
1646  */
is_global_init(struct task_struct * tsk)1647 static inline int is_global_init(struct task_struct *tsk)
1648 {
1649 	return task_tgid_nr(tsk) == 1;
1650 }
1651 
1652 extern struct pid *cad_pid;
1653 
1654 /*
1655  * Per process flags
1656  */
1657 #define PF_VCPU			0x00000001	/* I'm a virtual CPU */
1658 #define PF_IDLE			0x00000002	/* I am an IDLE thread */
1659 #define PF_EXITING		0x00000004	/* Getting shut down */
1660 #define PF_IO_WORKER		0x00000010	/* Task is an IO worker */
1661 #define PF_WQ_WORKER		0x00000020	/* I'm a workqueue worker */
1662 #define PF_FORKNOEXEC		0x00000040	/* Forked but didn't exec */
1663 #define PF_MCE_PROCESS		0x00000080      /* Process policy on mce errors */
1664 #define PF_SUPERPRIV		0x00000100	/* Used super-user privileges */
1665 #define PF_DUMPCORE		0x00000200	/* Dumped core */
1666 #define PF_SIGNALED		0x00000400	/* Killed by a signal */
1667 #define PF_MEMALLOC		0x00000800	/* Allocating memory */
1668 #define PF_NPROC_EXCEEDED	0x00001000	/* set_user() noticed that RLIMIT_NPROC was exceeded */
1669 #define PF_USED_MATH		0x00002000	/* If unset the fpu must be initialized before use */
1670 #define PF_USED_ASYNC		0x00004000	/* Used async_schedule*(), used by module init */
1671 #define PF_NOFREEZE		0x00008000	/* This thread should not be frozen */
1672 #define PF_FROZEN		0x00010000	/* Frozen for system suspend */
1673 #define PF_KSWAPD		0x00020000	/* I am kswapd */
1674 #define PF_MEMALLOC_NOFS	0x00040000	/* All allocation requests will inherit GFP_NOFS */
1675 #define PF_MEMALLOC_NOIO	0x00080000	/* All allocation requests will inherit GFP_NOIO */
1676 #define PF_LOCAL_THROTTLE	0x00100000	/* Throttle writes only against the bdi I write to,
1677 						 * I am cleaning dirty pages from some other bdi. */
1678 #define PF_KTHREAD		0x00200000	/* I am a kernel thread */
1679 #define PF_RANDOMIZE		0x00400000	/* Randomize virtual address space */
1680 #define PF_SWAPWRITE		0x00800000	/* Allowed to write to swap */
1681 #define PF_NO_SETAFFINITY	0x04000000	/* Userland is not allowed to meddle with cpus_mask */
1682 #define PF_MCE_EARLY		0x08000000      /* Early kill for mce process policy */
1683 #define PF_MEMALLOC_NOCMA	0x10000000	/* All allocation request will have _GFP_MOVABLE cleared */
1684 #define PF_FREEZER_SKIP		0x40000000	/* Freezer should not count it as freezable */
1685 #define PF_SUSPEND_TASK		0x80000000      /* This thread called freeze_processes() and should not be frozen */
1686 
1687 /*
1688  * Only the _current_ task can read/write to tsk->flags, but other
1689  * tasks can access tsk->flags in readonly mode for example
1690  * with tsk_used_math (like during threaded core dumping).
1691  * There is however an exception to this rule during ptrace
1692  * or during fork: the ptracer task is allowed to write to the
1693  * child->flags of its traced child (same goes for fork, the parent
1694  * can write to the child->flags), because we're guaranteed the
1695  * child is not running and in turn not changing child->flags
1696  * at the same time the parent does it.
1697  */
1698 #define clear_stopped_child_used_math(child)	do { (child)->flags &= ~PF_USED_MATH; } while (0)
1699 #define set_stopped_child_used_math(child)	do { (child)->flags |= PF_USED_MATH; } while (0)
1700 #define clear_used_math()			clear_stopped_child_used_math(current)
1701 #define set_used_math()				set_stopped_child_used_math(current)
1702 
1703 #define conditional_stopped_child_used_math(condition, child) \
1704 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1705 
1706 #define conditional_used_math(condition)	conditional_stopped_child_used_math(condition, current)
1707 
1708 #define copy_to_stopped_child_used_math(child) \
1709 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1710 
1711 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1712 #define tsk_used_math(p)			((p)->flags & PF_USED_MATH)
1713 #define used_math()				tsk_used_math(current)
1714 
is_percpu_thread(void)1715 static __always_inline bool is_percpu_thread(void)
1716 {
1717 #ifdef CONFIG_SMP
1718 	return (current->flags & PF_NO_SETAFFINITY) &&
1719 		(current->nr_cpus_allowed  == 1);
1720 #else
1721 	return true;
1722 #endif
1723 }
1724 
1725 /* Per-process atomic flags. */
1726 #define PFA_NO_NEW_PRIVS		0	/* May not gain new privileges. */
1727 #define PFA_SPREAD_PAGE			1	/* Spread page cache over cpuset */
1728 #define PFA_SPREAD_SLAB			2	/* Spread some slab caches over cpuset */
1729 #define PFA_SPEC_SSB_DISABLE		3	/* Speculative Store Bypass disabled */
1730 #define PFA_SPEC_SSB_FORCE_DISABLE	4	/* Speculative Store Bypass force disabled*/
1731 #define PFA_SPEC_IB_DISABLE		5	/* Indirect branch speculation restricted */
1732 #define PFA_SPEC_IB_FORCE_DISABLE	6	/* Indirect branch speculation permanently restricted */
1733 #define PFA_SPEC_SSB_NOEXEC		7	/* Speculative Store Bypass clear on execve() */
1734 
1735 #define TASK_PFA_TEST(name, func)					\
1736 	static inline bool task_##func(struct task_struct *p)		\
1737 	{ return test_bit(PFA_##name, &p->atomic_flags); }
1738 
1739 #define TASK_PFA_SET(name, func)					\
1740 	static inline void task_set_##func(struct task_struct *p)	\
1741 	{ set_bit(PFA_##name, &p->atomic_flags); }
1742 
1743 #define TASK_PFA_CLEAR(name, func)					\
1744 	static inline void task_clear_##func(struct task_struct *p)	\
1745 	{ clear_bit(PFA_##name, &p->atomic_flags); }
1746 
TASK_PFA_TEST(NO_NEW_PRIVS,no_new_privs)1747 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
1748 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
1749 
1750 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
1751 TASK_PFA_SET(SPREAD_PAGE, spread_page)
1752 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
1753 
1754 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
1755 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
1756 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
1757 
1758 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable)
1759 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable)
1760 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable)
1761 
1762 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1763 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1764 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1765 
1766 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1767 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1768 
1769 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable)
1770 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable)
1771 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable)
1772 
1773 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1774 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1775 
1776 static inline void
1777 current_restore_flags(unsigned long orig_flags, unsigned long flags)
1778 {
1779 	current->flags &= ~flags;
1780 	current->flags |= orig_flags & flags;
1781 }
1782 
1783 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
1784 extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed);
1785 #ifdef CONFIG_SMP
1786 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
1787 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
1788 #else
do_set_cpus_allowed(struct task_struct * p,const struct cpumask * new_mask)1789 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
1790 {
1791 }
set_cpus_allowed_ptr(struct task_struct * p,const struct cpumask * new_mask)1792 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
1793 {
1794 	if (!cpumask_test_cpu(0, new_mask))
1795 		return -EINVAL;
1796 	return 0;
1797 }
1798 #endif
1799 
1800 extern int yield_to(struct task_struct *p, bool preempt);
1801 extern void set_user_nice(struct task_struct *p, long nice);
1802 extern int task_prio(const struct task_struct *p);
1803 
1804 /**
1805  * task_nice - return the nice value of a given task.
1806  * @p: the task in question.
1807  *
1808  * Return: The nice value [ -20 ... 0 ... 19 ].
1809  */
task_nice(const struct task_struct * p)1810 static inline int task_nice(const struct task_struct *p)
1811 {
1812 	return PRIO_TO_NICE((p)->static_prio);
1813 }
1814 
1815 extern int can_nice(const struct task_struct *p, const int nice);
1816 extern int task_curr(const struct task_struct *p);
1817 extern int idle_cpu(int cpu);
1818 extern int available_idle_cpu(int cpu);
1819 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *);
1820 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *);
1821 extern void sched_set_fifo(struct task_struct *p);
1822 extern void sched_set_fifo_low(struct task_struct *p);
1823 extern void sched_set_normal(struct task_struct *p, int nice);
1824 extern int sched_setattr(struct task_struct *, const struct sched_attr *);
1825 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *);
1826 extern struct task_struct *idle_task(int cpu);
1827 
1828 /**
1829  * is_idle_task - is the specified task an idle task?
1830  * @p: the task in question.
1831  *
1832  * Return: 1 if @p is an idle task. 0 otherwise.
1833  */
is_idle_task(const struct task_struct * p)1834 static __always_inline bool is_idle_task(const struct task_struct *p)
1835 {
1836 	return !!(p->flags & PF_IDLE);
1837 }
1838 
1839 extern struct task_struct *curr_task(int cpu);
1840 extern void ia64_set_curr_task(int cpu, struct task_struct *p);
1841 
1842 void yield(void);
1843 
1844 union thread_union {
1845 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK
1846 	struct task_struct task;
1847 #endif
1848 #ifndef CONFIG_THREAD_INFO_IN_TASK
1849 	struct thread_info thread_info;
1850 #endif
1851 	unsigned long stack[THREAD_SIZE/sizeof(long)];
1852 };
1853 
1854 #ifndef CONFIG_THREAD_INFO_IN_TASK
1855 extern struct thread_info init_thread_info;
1856 #endif
1857 
1858 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
1859 
1860 #ifdef CONFIG_THREAD_INFO_IN_TASK
task_thread_info(struct task_struct * task)1861 static inline struct thread_info *task_thread_info(struct task_struct *task)
1862 {
1863 	return &task->thread_info;
1864 }
1865 #elif !defined(__HAVE_THREAD_FUNCTIONS)
1866 # define task_thread_info(task)	((struct thread_info *)(task)->stack)
1867 #endif
1868 
1869 /*
1870  * find a task by one of its numerical ids
1871  *
1872  * find_task_by_pid_ns():
1873  *      finds a task by its pid in the specified namespace
1874  * find_task_by_vpid():
1875  *      finds a task by its virtual pid
1876  *
1877  * see also find_vpid() etc in include/linux/pid.h
1878  */
1879 
1880 extern struct task_struct *find_task_by_vpid(pid_t nr);
1881 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns);
1882 
1883 /*
1884  * find a task by its virtual pid and get the task struct
1885  */
1886 extern struct task_struct *find_get_task_by_vpid(pid_t nr);
1887 
1888 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
1889 extern int wake_up_process(struct task_struct *tsk);
1890 extern void wake_up_new_task(struct task_struct *tsk);
1891 
1892 #ifdef CONFIG_SMP
1893 extern void kick_process(struct task_struct *tsk);
1894 #else
kick_process(struct task_struct * tsk)1895 static inline void kick_process(struct task_struct *tsk) { }
1896 #endif
1897 
1898 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
1899 
set_task_comm(struct task_struct * tsk,const char * from)1900 static inline void set_task_comm(struct task_struct *tsk, const char *from)
1901 {
1902 	__set_task_comm(tsk, from, false);
1903 }
1904 
1905 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk);
1906 #define get_task_comm(buf, tsk) ({			\
1907 	BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN);	\
1908 	__get_task_comm(buf, sizeof(buf), tsk);		\
1909 })
1910 
1911 #ifdef CONFIG_SMP
scheduler_ipi(void)1912 static __always_inline void scheduler_ipi(void)
1913 {
1914 	/*
1915 	 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting
1916 	 * TIF_NEED_RESCHED remotely (for the first time) will also send
1917 	 * this IPI.
1918 	 */
1919 	preempt_fold_need_resched();
1920 }
1921 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
1922 #else
scheduler_ipi(void)1923 static inline void scheduler_ipi(void) { }
wait_task_inactive(struct task_struct * p,long match_state)1924 static inline unsigned long wait_task_inactive(struct task_struct *p, long match_state)
1925 {
1926 	return 1;
1927 }
1928 #endif
1929 
1930 /*
1931  * Set thread flags in other task's structures.
1932  * See asm/thread_info.h for TIF_xxxx flags available:
1933  */
set_tsk_thread_flag(struct task_struct * tsk,int flag)1934 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
1935 {
1936 	set_ti_thread_flag(task_thread_info(tsk), flag);
1937 }
1938 
clear_tsk_thread_flag(struct task_struct * tsk,int flag)1939 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1940 {
1941 	clear_ti_thread_flag(task_thread_info(tsk), flag);
1942 }
1943 
update_tsk_thread_flag(struct task_struct * tsk,int flag,bool value)1944 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag,
1945 					  bool value)
1946 {
1947 	update_ti_thread_flag(task_thread_info(tsk), flag, value);
1948 }
1949 
test_and_set_tsk_thread_flag(struct task_struct * tsk,int flag)1950 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
1951 {
1952 	return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
1953 }
1954 
test_and_clear_tsk_thread_flag(struct task_struct * tsk,int flag)1955 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1956 {
1957 	return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
1958 }
1959 
test_tsk_thread_flag(struct task_struct * tsk,int flag)1960 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
1961 {
1962 	return test_ti_thread_flag(task_thread_info(tsk), flag);
1963 }
1964 
set_tsk_need_resched(struct task_struct * tsk)1965 static inline void set_tsk_need_resched(struct task_struct *tsk)
1966 {
1967 	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1968 }
1969 
clear_tsk_need_resched(struct task_struct * tsk)1970 static inline void clear_tsk_need_resched(struct task_struct *tsk)
1971 {
1972 	clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1973 }
1974 
test_tsk_need_resched(struct task_struct * tsk)1975 static inline int test_tsk_need_resched(struct task_struct *tsk)
1976 {
1977 	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
1978 }
1979 
1980 /*
1981  * cond_resched() and cond_resched_lock(): latency reduction via
1982  * explicit rescheduling in places that are safe. The return
1983  * value indicates whether a reschedule was done in fact.
1984  * cond_resched_lock() will drop the spinlock before scheduling,
1985  */
1986 #ifndef CONFIG_PREEMPTION
1987 extern int _cond_resched(void);
1988 #else
_cond_resched(void)1989 static inline int _cond_resched(void) { return 0; }
1990 #endif
1991 
1992 #define cond_resched() ({			\
1993 	___might_sleep(__FILE__, __LINE__, 0);	\
1994 	_cond_resched();			\
1995 })
1996 
1997 extern int __cond_resched_lock(spinlock_t *lock);
1998 
1999 #define cond_resched_lock(lock) ({				\
2000 	___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
2001 	__cond_resched_lock(lock);				\
2002 })
2003 
cond_resched_rcu(void)2004 static inline void cond_resched_rcu(void)
2005 {
2006 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
2007 	rcu_read_unlock();
2008 	cond_resched();
2009 	rcu_read_lock();
2010 #endif
2011 }
2012 
2013 /*
2014  * Does a critical section need to be broken due to another
2015  * task waiting?: (technically does not depend on CONFIG_PREEMPTION,
2016  * but a general need for low latency)
2017  */
spin_needbreak(spinlock_t * lock)2018 static inline int spin_needbreak(spinlock_t *lock)
2019 {
2020 #ifdef CONFIG_PREEMPTION
2021 	return spin_is_contended(lock);
2022 #else
2023 	return 0;
2024 #endif
2025 }
2026 
need_resched(void)2027 static __always_inline bool need_resched(void)
2028 {
2029 	return unlikely(tif_need_resched());
2030 }
2031 
2032 /*
2033  * Wrappers for p->thread_info->cpu access. No-op on UP.
2034  */
2035 #ifdef CONFIG_SMP
2036 
task_cpu(const struct task_struct * p)2037 static inline unsigned int task_cpu(const struct task_struct *p)
2038 {
2039 #ifdef CONFIG_THREAD_INFO_IN_TASK
2040 	return READ_ONCE(p->cpu);
2041 #else
2042 	return READ_ONCE(task_thread_info(p)->cpu);
2043 #endif
2044 }
2045 
2046 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2047 
2048 #else
2049 
task_cpu(const struct task_struct * p)2050 static inline unsigned int task_cpu(const struct task_struct *p)
2051 {
2052 	return 0;
2053 }
2054 
set_task_cpu(struct task_struct * p,unsigned int cpu)2055 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2056 {
2057 }
2058 
2059 #endif /* CONFIG_SMP */
2060 
2061 /*
2062  * In order to reduce various lock holder preemption latencies provide an
2063  * interface to see if a vCPU is currently running or not.
2064  *
2065  * This allows us to terminate optimistic spin loops and block, analogous to
2066  * the native optimistic spin heuristic of testing if the lock owner task is
2067  * running or not.
2068  */
2069 #ifndef vcpu_is_preempted
vcpu_is_preempted(int cpu)2070 static inline bool vcpu_is_preempted(int cpu)
2071 {
2072 	return false;
2073 }
2074 #endif
2075 
2076 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2077 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2078 
2079 #ifndef TASK_SIZE_OF
2080 #define TASK_SIZE_OF(tsk)	TASK_SIZE
2081 #endif
2082 
2083 #ifdef CONFIG_RSEQ
2084 
2085 /*
2086  * Map the event mask on the user-space ABI enum rseq_cs_flags
2087  * for direct mask checks.
2088  */
2089 enum rseq_event_mask_bits {
2090 	RSEQ_EVENT_PREEMPT_BIT	= RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT,
2091 	RSEQ_EVENT_SIGNAL_BIT	= RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT,
2092 	RSEQ_EVENT_MIGRATE_BIT	= RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT,
2093 };
2094 
2095 enum rseq_event_mask {
2096 	RSEQ_EVENT_PREEMPT	= (1U << RSEQ_EVENT_PREEMPT_BIT),
2097 	RSEQ_EVENT_SIGNAL	= (1U << RSEQ_EVENT_SIGNAL_BIT),
2098 	RSEQ_EVENT_MIGRATE	= (1U << RSEQ_EVENT_MIGRATE_BIT),
2099 };
2100 
rseq_set_notify_resume(struct task_struct * t)2101 static inline void rseq_set_notify_resume(struct task_struct *t)
2102 {
2103 	if (t->rseq)
2104 		set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
2105 }
2106 
2107 void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs);
2108 
rseq_handle_notify_resume(struct ksignal * ksig,struct pt_regs * regs)2109 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
2110 					     struct pt_regs *regs)
2111 {
2112 	if (current->rseq)
2113 		__rseq_handle_notify_resume(ksig, regs);
2114 }
2115 
rseq_signal_deliver(struct ksignal * ksig,struct pt_regs * regs)2116 static inline void rseq_signal_deliver(struct ksignal *ksig,
2117 				       struct pt_regs *regs)
2118 {
2119 	preempt_disable();
2120 	__set_bit(RSEQ_EVENT_SIGNAL_BIT, &current->rseq_event_mask);
2121 	preempt_enable();
2122 	rseq_handle_notify_resume(ksig, regs);
2123 }
2124 
2125 /* rseq_preempt() requires preemption to be disabled. */
rseq_preempt(struct task_struct * t)2126 static inline void rseq_preempt(struct task_struct *t)
2127 {
2128 	__set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask);
2129 	rseq_set_notify_resume(t);
2130 }
2131 
2132 /* rseq_migrate() requires preemption to be disabled. */
rseq_migrate(struct task_struct * t)2133 static inline void rseq_migrate(struct task_struct *t)
2134 {
2135 	__set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask);
2136 	rseq_set_notify_resume(t);
2137 }
2138 
2139 /*
2140  * If parent process has a registered restartable sequences area, the
2141  * child inherits. Unregister rseq for a clone with CLONE_VM set.
2142  */
rseq_fork(struct task_struct * t,unsigned long clone_flags)2143 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
2144 {
2145 	if (clone_flags & CLONE_VM) {
2146 		t->rseq = NULL;
2147 		t->rseq_sig = 0;
2148 		t->rseq_event_mask = 0;
2149 	} else {
2150 		t->rseq = current->rseq;
2151 		t->rseq_sig = current->rseq_sig;
2152 		t->rseq_event_mask = current->rseq_event_mask;
2153 	}
2154 }
2155 
rseq_execve(struct task_struct * t)2156 static inline void rseq_execve(struct task_struct *t)
2157 {
2158 	t->rseq = NULL;
2159 	t->rseq_sig = 0;
2160 	t->rseq_event_mask = 0;
2161 }
2162 
2163 #else
2164 
rseq_set_notify_resume(struct task_struct * t)2165 static inline void rseq_set_notify_resume(struct task_struct *t)
2166 {
2167 }
rseq_handle_notify_resume(struct ksignal * ksig,struct pt_regs * regs)2168 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
2169 					     struct pt_regs *regs)
2170 {
2171 }
rseq_signal_deliver(struct ksignal * ksig,struct pt_regs * regs)2172 static inline void rseq_signal_deliver(struct ksignal *ksig,
2173 				       struct pt_regs *regs)
2174 {
2175 }
rseq_preempt(struct task_struct * t)2176 static inline void rseq_preempt(struct task_struct *t)
2177 {
2178 }
rseq_migrate(struct task_struct * t)2179 static inline void rseq_migrate(struct task_struct *t)
2180 {
2181 }
rseq_fork(struct task_struct * t,unsigned long clone_flags)2182 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
2183 {
2184 }
rseq_execve(struct task_struct * t)2185 static inline void rseq_execve(struct task_struct *t)
2186 {
2187 }
2188 
2189 #endif
2190 
2191 #ifdef CONFIG_DEBUG_RSEQ
2192 
2193 void rseq_syscall(struct pt_regs *regs);
2194 
2195 #else
2196 
rseq_syscall(struct pt_regs * regs)2197 static inline void rseq_syscall(struct pt_regs *regs)
2198 {
2199 }
2200 
2201 #endif
2202 
2203 const struct sched_avg *sched_trace_cfs_rq_avg(struct cfs_rq *cfs_rq);
2204 char *sched_trace_cfs_rq_path(struct cfs_rq *cfs_rq, char *str, int len);
2205 int sched_trace_cfs_rq_cpu(struct cfs_rq *cfs_rq);
2206 
2207 const struct sched_avg *sched_trace_rq_avg_rt(struct rq *rq);
2208 const struct sched_avg *sched_trace_rq_avg_dl(struct rq *rq);
2209 const struct sched_avg *sched_trace_rq_avg_irq(struct rq *rq);
2210 
2211 int sched_trace_rq_cpu(struct rq *rq);
2212 int sched_trace_rq_cpu_capacity(struct rq *rq);
2213 int sched_trace_rq_nr_running(struct rq *rq);
2214 
2215 const struct cpumask *sched_trace_rd_span(struct root_domain *rd);
2216 
2217 #endif
2218