xref: /linux-6.15/include/linux/sched.h (revision acc65769)
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/kmsan_types.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/syscall_user_dispatch.h>
32 #include <linux/mm_types_task.h>
33 #include <linux/task_io_accounting.h>
34 #include <linux/posix-timers.h>
35 #include <linux/rseq.h>
36 #include <linux/seqlock.h>
37 #include <linux/kcsan.h>
38 #include <linux/rv.h>
39 #include <linux/livepatch_sched.h>
40 #include <asm/kmap_size.h>
41 
42 /* task_struct member predeclarations (sorted alphabetically): */
43 struct audit_context;
44 struct bio_list;
45 struct blk_plug;
46 struct bpf_local_storage;
47 struct bpf_run_ctx;
48 struct capture_control;
49 struct cfs_rq;
50 struct fs_struct;
51 struct futex_pi_state;
52 struct io_context;
53 struct io_uring_task;
54 struct mempolicy;
55 struct nameidata;
56 struct nsproxy;
57 struct perf_event_context;
58 struct pid_namespace;
59 struct pipe_inode_info;
60 struct rcu_node;
61 struct reclaim_state;
62 struct robust_list_head;
63 struct root_domain;
64 struct rq;
65 struct sched_attr;
66 struct sched_dl_entity;
67 struct seq_file;
68 struct sighand_struct;
69 struct signal_struct;
70 struct task_delay_info;
71 struct task_group;
72 struct task_struct;
73 struct user_event_mm;
74 
75 /*
76  * Task state bitmask. NOTE! These bits are also
77  * encoded in fs/proc/array.c: get_task_state().
78  *
79  * We have two separate sets of flags: task->__state
80  * is about runnability, while task->exit_state are
81  * about the task exiting. Confusing, but this way
82  * modifying one set can't modify the other one by
83  * mistake.
84  */
85 
86 /* Used in tsk->__state: */
87 #define TASK_RUNNING			0x00000000
88 #define TASK_INTERRUPTIBLE		0x00000001
89 #define TASK_UNINTERRUPTIBLE		0x00000002
90 #define __TASK_STOPPED			0x00000004
91 #define __TASK_TRACED			0x00000008
92 /* Used in tsk->exit_state: */
93 #define EXIT_DEAD			0x00000010
94 #define EXIT_ZOMBIE			0x00000020
95 #define EXIT_TRACE			(EXIT_ZOMBIE | EXIT_DEAD)
96 /* Used in tsk->__state again: */
97 #define TASK_PARKED			0x00000040
98 #define TASK_DEAD			0x00000080
99 #define TASK_WAKEKILL			0x00000100
100 #define TASK_WAKING			0x00000200
101 #define TASK_NOLOAD			0x00000400
102 #define TASK_NEW			0x00000800
103 #define TASK_RTLOCK_WAIT		0x00001000
104 #define TASK_FREEZABLE			0x00002000
105 #define __TASK_FREEZABLE_UNSAFE	       (0x00004000 * IS_ENABLED(CONFIG_LOCKDEP))
106 #define TASK_FROZEN			0x00008000
107 #define TASK_STATE_MAX			0x00010000
108 
109 #define TASK_ANY			(TASK_STATE_MAX-1)
110 
111 /*
112  * DO NOT ADD ANY NEW USERS !
113  */
114 #define TASK_FREEZABLE_UNSAFE		(TASK_FREEZABLE | __TASK_FREEZABLE_UNSAFE)
115 
116 /* Convenience macros for the sake of set_current_state: */
117 #define TASK_KILLABLE			(TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
118 #define TASK_STOPPED			(TASK_WAKEKILL | __TASK_STOPPED)
119 #define TASK_TRACED			__TASK_TRACED
120 
121 #define TASK_IDLE			(TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
122 
123 /* Convenience macros for the sake of wake_up(): */
124 #define TASK_NORMAL			(TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
125 
126 /* get_task_state(): */
127 #define TASK_REPORT			(TASK_RUNNING | TASK_INTERRUPTIBLE | \
128 					 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
129 					 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
130 					 TASK_PARKED)
131 
132 #define task_is_running(task)		(READ_ONCE((task)->__state) == TASK_RUNNING)
133 
134 #define task_is_traced(task)		((READ_ONCE(task->jobctl) & JOBCTL_TRACED) != 0)
135 #define task_is_stopped(task)		((READ_ONCE(task->jobctl) & JOBCTL_STOPPED) != 0)
136 #define task_is_stopped_or_traced(task)	((READ_ONCE(task->jobctl) & (JOBCTL_STOPPED | JOBCTL_TRACED)) != 0)
137 
138 /*
139  * Special states are those that do not use the normal wait-loop pattern. See
140  * the comment with set_special_state().
141  */
142 #define is_special_task_state(state)				\
143 	((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD))
144 
145 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
146 # define debug_normal_state_change(state_value)				\
147 	do {								\
148 		WARN_ON_ONCE(is_special_task_state(state_value));	\
149 		current->task_state_change = _THIS_IP_;			\
150 	} while (0)
151 
152 # define debug_special_state_change(state_value)			\
153 	do {								\
154 		WARN_ON_ONCE(!is_special_task_state(state_value));	\
155 		current->task_state_change = _THIS_IP_;			\
156 	} while (0)
157 
158 # define debug_rtlock_wait_set_state()					\
159 	do {								 \
160 		current->saved_state_change = current->task_state_change;\
161 		current->task_state_change = _THIS_IP_;			 \
162 	} while (0)
163 
164 # define debug_rtlock_wait_restore_state()				\
165 	do {								 \
166 		current->task_state_change = current->saved_state_change;\
167 	} while (0)
168 
169 #else
170 # define debug_normal_state_change(cond)	do { } while (0)
171 # define debug_special_state_change(cond)	do { } while (0)
172 # define debug_rtlock_wait_set_state()		do { } while (0)
173 # define debug_rtlock_wait_restore_state()	do { } while (0)
174 #endif
175 
176 /*
177  * set_current_state() includes a barrier so that the write of current->__state
178  * is correctly serialised wrt the caller's subsequent test of whether to
179  * actually sleep:
180  *
181  *   for (;;) {
182  *	set_current_state(TASK_UNINTERRUPTIBLE);
183  *	if (CONDITION)
184  *	   break;
185  *
186  *	schedule();
187  *   }
188  *   __set_current_state(TASK_RUNNING);
189  *
190  * If the caller does not need such serialisation (because, for instance, the
191  * CONDITION test and condition change and wakeup are under the same lock) then
192  * use __set_current_state().
193  *
194  * The above is typically ordered against the wakeup, which does:
195  *
196  *   CONDITION = 1;
197  *   wake_up_state(p, TASK_UNINTERRUPTIBLE);
198  *
199  * where wake_up_state()/try_to_wake_up() executes a full memory barrier before
200  * accessing p->__state.
201  *
202  * Wakeup will do: if (@state & p->__state) p->__state = TASK_RUNNING, that is,
203  * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
204  * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
205  *
206  * However, with slightly different timing the wakeup TASK_RUNNING store can
207  * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not
208  * a problem either because that will result in one extra go around the loop
209  * and our @cond test will save the day.
210  *
211  * Also see the comments of try_to_wake_up().
212  */
213 #define __set_current_state(state_value)				\
214 	do {								\
215 		debug_normal_state_change((state_value));		\
216 		WRITE_ONCE(current->__state, (state_value));		\
217 	} while (0)
218 
219 #define set_current_state(state_value)					\
220 	do {								\
221 		debug_normal_state_change((state_value));		\
222 		smp_store_mb(current->__state, (state_value));		\
223 	} while (0)
224 
225 /*
226  * set_special_state() should be used for those states when the blocking task
227  * can not use the regular condition based wait-loop. In that case we must
228  * serialize against wakeups such that any possible in-flight TASK_RUNNING
229  * stores will not collide with our state change.
230  */
231 #define set_special_state(state_value)					\
232 	do {								\
233 		unsigned long flags; /* may shadow */			\
234 									\
235 		raw_spin_lock_irqsave(&current->pi_lock, flags);	\
236 		debug_special_state_change((state_value));		\
237 		WRITE_ONCE(current->__state, (state_value));		\
238 		raw_spin_unlock_irqrestore(&current->pi_lock, flags);	\
239 	} while (0)
240 
241 /*
242  * PREEMPT_RT specific variants for "sleeping" spin/rwlocks
243  *
244  * RT's spin/rwlock substitutions are state preserving. The state of the
245  * task when blocking on the lock is saved in task_struct::saved_state and
246  * restored after the lock has been acquired.  These operations are
247  * serialized by task_struct::pi_lock against try_to_wake_up(). Any non RT
248  * lock related wakeups while the task is blocked on the lock are
249  * redirected to operate on task_struct::saved_state to ensure that these
250  * are not dropped. On restore task_struct::saved_state is set to
251  * TASK_RUNNING so any wakeup attempt redirected to saved_state will fail.
252  *
253  * The lock operation looks like this:
254  *
255  *	current_save_and_set_rtlock_wait_state();
256  *	for (;;) {
257  *		if (try_lock())
258  *			break;
259  *		raw_spin_unlock_irq(&lock->wait_lock);
260  *		schedule_rtlock();
261  *		raw_spin_lock_irq(&lock->wait_lock);
262  *		set_current_state(TASK_RTLOCK_WAIT);
263  *	}
264  *	current_restore_rtlock_saved_state();
265  */
266 #define current_save_and_set_rtlock_wait_state()			\
267 	do {								\
268 		lockdep_assert_irqs_disabled();				\
269 		raw_spin_lock(&current->pi_lock);			\
270 		current->saved_state = current->__state;		\
271 		debug_rtlock_wait_set_state();				\
272 		WRITE_ONCE(current->__state, TASK_RTLOCK_WAIT);		\
273 		raw_spin_unlock(&current->pi_lock);			\
274 	} while (0);
275 
276 #define current_restore_rtlock_saved_state()				\
277 	do {								\
278 		lockdep_assert_irqs_disabled();				\
279 		raw_spin_lock(&current->pi_lock);			\
280 		debug_rtlock_wait_restore_state();			\
281 		WRITE_ONCE(current->__state, current->saved_state);	\
282 		current->saved_state = TASK_RUNNING;			\
283 		raw_spin_unlock(&current->pi_lock);			\
284 	} while (0);
285 
286 #define get_current_state()	READ_ONCE(current->__state)
287 
288 /*
289  * Define the task command name length as enum, then it can be visible to
290  * BPF programs.
291  */
292 enum {
293 	TASK_COMM_LEN = 16,
294 };
295 
296 extern void scheduler_tick(void);
297 
298 #define	MAX_SCHEDULE_TIMEOUT		LONG_MAX
299 
300 extern long schedule_timeout(long timeout);
301 extern long schedule_timeout_interruptible(long timeout);
302 extern long schedule_timeout_killable(long timeout);
303 extern long schedule_timeout_uninterruptible(long timeout);
304 extern long schedule_timeout_idle(long timeout);
305 asmlinkage void schedule(void);
306 extern void schedule_preempt_disabled(void);
307 asmlinkage void preempt_schedule_irq(void);
308 #ifdef CONFIG_PREEMPT_RT
309  extern void schedule_rtlock(void);
310 #endif
311 
312 extern int __must_check io_schedule_prepare(void);
313 extern void io_schedule_finish(int token);
314 extern long io_schedule_timeout(long timeout);
315 extern void io_schedule(void);
316 
317 /**
318  * struct prev_cputime - snapshot of system and user cputime
319  * @utime: time spent in user mode
320  * @stime: time spent in system mode
321  * @lock: protects the above two fields
322  *
323  * Stores previous user/system time values such that we can guarantee
324  * monotonicity.
325  */
326 struct prev_cputime {
327 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
328 	u64				utime;
329 	u64				stime;
330 	raw_spinlock_t			lock;
331 #endif
332 };
333 
334 enum vtime_state {
335 	/* Task is sleeping or running in a CPU with VTIME inactive: */
336 	VTIME_INACTIVE = 0,
337 	/* Task is idle */
338 	VTIME_IDLE,
339 	/* Task runs in kernelspace in a CPU with VTIME active: */
340 	VTIME_SYS,
341 	/* Task runs in userspace in a CPU with VTIME active: */
342 	VTIME_USER,
343 	/* Task runs as guests in a CPU with VTIME active: */
344 	VTIME_GUEST,
345 };
346 
347 struct vtime {
348 	seqcount_t		seqcount;
349 	unsigned long long	starttime;
350 	enum vtime_state	state;
351 	unsigned int		cpu;
352 	u64			utime;
353 	u64			stime;
354 	u64			gtime;
355 };
356 
357 /*
358  * Utilization clamp constraints.
359  * @UCLAMP_MIN:	Minimum utilization
360  * @UCLAMP_MAX:	Maximum utilization
361  * @UCLAMP_CNT:	Utilization clamp constraints count
362  */
363 enum uclamp_id {
364 	UCLAMP_MIN = 0,
365 	UCLAMP_MAX,
366 	UCLAMP_CNT
367 };
368 
369 #ifdef CONFIG_SMP
370 extern struct root_domain def_root_domain;
371 extern struct mutex sched_domains_mutex;
372 #endif
373 
374 struct sched_param {
375 	int sched_priority;
376 };
377 
378 struct sched_info {
379 #ifdef CONFIG_SCHED_INFO
380 	/* Cumulative counters: */
381 
382 	/* # of times we have run on this CPU: */
383 	unsigned long			pcount;
384 
385 	/* Time spent waiting on a runqueue: */
386 	unsigned long long		run_delay;
387 
388 	/* Timestamps: */
389 
390 	/* When did we last run on a CPU? */
391 	unsigned long long		last_arrival;
392 
393 	/* When were we last queued to run? */
394 	unsigned long long		last_queued;
395 
396 #endif /* CONFIG_SCHED_INFO */
397 };
398 
399 /*
400  * Integer metrics need fixed point arithmetic, e.g., sched/fair
401  * has a few: load, load_avg, util_avg, freq, and capacity.
402  *
403  * We define a basic fixed point arithmetic range, and then formalize
404  * all these metrics based on that basic range.
405  */
406 # define SCHED_FIXEDPOINT_SHIFT		10
407 # define SCHED_FIXEDPOINT_SCALE		(1L << SCHED_FIXEDPOINT_SHIFT)
408 
409 /* Increase resolution of cpu_capacity calculations */
410 # define SCHED_CAPACITY_SHIFT		SCHED_FIXEDPOINT_SHIFT
411 # define SCHED_CAPACITY_SCALE		(1L << SCHED_CAPACITY_SHIFT)
412 
413 struct load_weight {
414 	unsigned long			weight;
415 	u32				inv_weight;
416 };
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 	unsigned int			util_est;
473 } ____cacheline_aligned;
474 
475 /*
476  * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg
477  * updates. When a task is dequeued, its util_est should not be updated if its
478  * util_avg has not been updated in the meantime.
479  * This information is mapped into the MSB bit of util_est at dequeue time.
480  * Since max value of util_est for a task is 1024 (PELT util_avg for a task)
481  * it is safe to use MSB.
482  */
483 #define UTIL_EST_WEIGHT_SHIFT		2
484 #define UTIL_AVG_UNCHANGED		0x80000000
485 
486 struct sched_statistics {
487 #ifdef CONFIG_SCHEDSTATS
488 	u64				wait_start;
489 	u64				wait_max;
490 	u64				wait_count;
491 	u64				wait_sum;
492 	u64				iowait_count;
493 	u64				iowait_sum;
494 
495 	u64				sleep_start;
496 	u64				sleep_max;
497 	s64				sum_sleep_runtime;
498 
499 	u64				block_start;
500 	u64				block_max;
501 	s64				sum_block_runtime;
502 
503 	s64				exec_max;
504 	u64				slice_max;
505 
506 	u64				nr_migrations_cold;
507 	u64				nr_failed_migrations_affine;
508 	u64				nr_failed_migrations_running;
509 	u64				nr_failed_migrations_hot;
510 	u64				nr_forced_migrations;
511 
512 	u64				nr_wakeups;
513 	u64				nr_wakeups_sync;
514 	u64				nr_wakeups_migrate;
515 	u64				nr_wakeups_local;
516 	u64				nr_wakeups_remote;
517 	u64				nr_wakeups_affine;
518 	u64				nr_wakeups_affine_attempts;
519 	u64				nr_wakeups_passive;
520 	u64				nr_wakeups_idle;
521 
522 #ifdef CONFIG_SCHED_CORE
523 	u64				core_forceidle_sum;
524 #endif
525 #endif /* CONFIG_SCHEDSTATS */
526 } ____cacheline_aligned;
527 
528 struct sched_entity {
529 	/* For load-balancing: */
530 	struct load_weight		load;
531 	struct rb_node			run_node;
532 	u64				deadline;
533 	u64				min_vruntime;
534 
535 	struct list_head		group_node;
536 	unsigned int			on_rq;
537 
538 	u64				exec_start;
539 	u64				sum_exec_runtime;
540 	u64				prev_sum_exec_runtime;
541 	u64				vruntime;
542 	s64				vlag;
543 	u64				slice;
544 
545 	u64				nr_migrations;
546 
547 #ifdef CONFIG_FAIR_GROUP_SCHED
548 	int				depth;
549 	struct sched_entity		*parent;
550 	/* rq on which this entity is (to be) queued: */
551 	struct cfs_rq			*cfs_rq;
552 	/* rq "owned" by this entity/group: */
553 	struct cfs_rq			*my_q;
554 	/* cached value of my_q->h_nr_running */
555 	unsigned long			runnable_weight;
556 #endif
557 
558 #ifdef CONFIG_SMP
559 	/*
560 	 * Per entity load average tracking.
561 	 *
562 	 * Put into separate cache line so it does not
563 	 * collide with read-mostly values above.
564 	 */
565 	struct sched_avg		avg;
566 #endif
567 };
568 
569 struct sched_rt_entity {
570 	struct list_head		run_list;
571 	unsigned long			timeout;
572 	unsigned long			watchdog_stamp;
573 	unsigned int			time_slice;
574 	unsigned short			on_rq;
575 	unsigned short			on_list;
576 
577 	struct sched_rt_entity		*back;
578 #ifdef CONFIG_RT_GROUP_SCHED
579 	struct sched_rt_entity		*parent;
580 	/* rq on which this entity is (to be) queued: */
581 	struct rt_rq			*rt_rq;
582 	/* rq "owned" by this entity/group: */
583 	struct rt_rq			*my_q;
584 #endif
585 } __randomize_layout;
586 
587 typedef bool (*dl_server_has_tasks_f)(struct sched_dl_entity *);
588 typedef struct task_struct *(*dl_server_pick_f)(struct sched_dl_entity *);
589 
590 struct sched_dl_entity {
591 	struct rb_node			rb_node;
592 
593 	/*
594 	 * Original scheduling parameters. Copied here from sched_attr
595 	 * during sched_setattr(), they will remain the same until
596 	 * the next sched_setattr().
597 	 */
598 	u64				dl_runtime;	/* Maximum runtime for each instance	*/
599 	u64				dl_deadline;	/* Relative deadline of each instance	*/
600 	u64				dl_period;	/* Separation of two instances (period) */
601 	u64				dl_bw;		/* dl_runtime / dl_period		*/
602 	u64				dl_density;	/* dl_runtime / dl_deadline		*/
603 
604 	/*
605 	 * Actual scheduling parameters. Initialized with the values above,
606 	 * they are continuously updated during task execution. Note that
607 	 * the remaining runtime could be < 0 in case we are in overrun.
608 	 */
609 	s64				runtime;	/* Remaining runtime for this instance	*/
610 	u64				deadline;	/* Absolute deadline for this instance	*/
611 	unsigned int			flags;		/* Specifying the scheduler behaviour	*/
612 
613 	/*
614 	 * Some bool flags:
615 	 *
616 	 * @dl_throttled tells if we exhausted the runtime. If so, the
617 	 * task has to wait for a replenishment to be performed at the
618 	 * next firing of dl_timer.
619 	 *
620 	 * @dl_yielded tells if task gave up the CPU before consuming
621 	 * all its available runtime during the last job.
622 	 *
623 	 * @dl_non_contending tells if the task is inactive while still
624 	 * contributing to the active utilization. In other words, it
625 	 * indicates if the inactive timer has been armed and its handler
626 	 * has not been executed yet. This flag is useful to avoid race
627 	 * conditions between the inactive timer handler and the wakeup
628 	 * code.
629 	 *
630 	 * @dl_overrun tells if the task asked to be informed about runtime
631 	 * overruns.
632 	 */
633 	unsigned int			dl_throttled      : 1;
634 	unsigned int			dl_yielded        : 1;
635 	unsigned int			dl_non_contending : 1;
636 	unsigned int			dl_overrun	  : 1;
637 	unsigned int			dl_server         : 1;
638 
639 	/*
640 	 * Bandwidth enforcement timer. Each -deadline task has its
641 	 * own bandwidth to be enforced, thus we need one timer per task.
642 	 */
643 	struct hrtimer			dl_timer;
644 
645 	/*
646 	 * Inactive timer, responsible for decreasing the active utilization
647 	 * at the "0-lag time". When a -deadline task blocks, it contributes
648 	 * to GRUB's active utilization until the "0-lag time", hence a
649 	 * timer is needed to decrease the active utilization at the correct
650 	 * time.
651 	 */
652 	struct hrtimer			inactive_timer;
653 
654 	/*
655 	 * Bits for DL-server functionality. Also see the comment near
656 	 * dl_server_update().
657 	 *
658 	 * @rq the runqueue this server is for
659 	 *
660 	 * @server_has_tasks() returns true if @server_pick return a
661 	 * runnable task.
662 	 */
663 	struct rq			*rq;
664 	dl_server_has_tasks_f		server_has_tasks;
665 	dl_server_pick_f		server_pick;
666 
667 #ifdef CONFIG_RT_MUTEXES
668 	/*
669 	 * Priority Inheritance. When a DEADLINE scheduling entity is boosted
670 	 * pi_se points to the donor, otherwise points to the dl_se it belongs
671 	 * to (the original one/itself).
672 	 */
673 	struct sched_dl_entity *pi_se;
674 #endif
675 };
676 
677 #ifdef CONFIG_UCLAMP_TASK
678 /* Number of utilization clamp buckets (shorter alias) */
679 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT
680 
681 /*
682  * Utilization clamp for a scheduling entity
683  * @value:		clamp value "assigned" to a se
684  * @bucket_id:		bucket index corresponding to the "assigned" value
685  * @active:		the se is currently refcounted in a rq's bucket
686  * @user_defined:	the requested clamp value comes from user-space
687  *
688  * The bucket_id is the index of the clamp bucket matching the clamp value
689  * which is pre-computed and stored to avoid expensive integer divisions from
690  * the fast path.
691  *
692  * The active bit is set whenever a task has got an "effective" value assigned,
693  * which can be different from the clamp value "requested" from user-space.
694  * This allows to know a task is refcounted in the rq's bucket corresponding
695  * to the "effective" bucket_id.
696  *
697  * The user_defined bit is set whenever a task has got a task-specific clamp
698  * value requested from userspace, i.e. the system defaults apply to this task
699  * just as a restriction. This allows to relax default clamps when a less
700  * restrictive task-specific value has been requested, thus allowing to
701  * implement a "nice" semantic. For example, a task running with a 20%
702  * default boost can still drop its own boosting to 0%.
703  */
704 struct uclamp_se {
705 	unsigned int value		: bits_per(SCHED_CAPACITY_SCALE);
706 	unsigned int bucket_id		: bits_per(UCLAMP_BUCKETS);
707 	unsigned int active		: 1;
708 	unsigned int user_defined	: 1;
709 };
710 #endif /* CONFIG_UCLAMP_TASK */
711 
712 union rcu_special {
713 	struct {
714 		u8			blocked;
715 		u8			need_qs;
716 		u8			exp_hint; /* Hint for performance. */
717 		u8			need_mb; /* Readers need smp_mb(). */
718 	} b; /* Bits. */
719 	u32 s; /* Set of bits. */
720 };
721 
722 enum perf_event_task_context {
723 	perf_invalid_context = -1,
724 	perf_hw_context = 0,
725 	perf_sw_context,
726 	perf_nr_task_contexts,
727 };
728 
729 struct wake_q_node {
730 	struct wake_q_node *next;
731 };
732 
733 struct kmap_ctrl {
734 #ifdef CONFIG_KMAP_LOCAL
735 	int				idx;
736 	pte_t				pteval[KM_MAX_IDX];
737 #endif
738 };
739 
740 struct task_struct {
741 #ifdef CONFIG_THREAD_INFO_IN_TASK
742 	/*
743 	 * For reasons of header soup (see current_thread_info()), this
744 	 * must be the first element of task_struct.
745 	 */
746 	struct thread_info		thread_info;
747 #endif
748 	unsigned int			__state;
749 
750 	/* saved state for "spinlock sleepers" */
751 	unsigned int			saved_state;
752 
753 	/*
754 	 * This begins the randomizable portion of task_struct. Only
755 	 * scheduling-critical items should be added above here.
756 	 */
757 	randomized_struct_fields_start
758 
759 	void				*stack;
760 	refcount_t			usage;
761 	/* Per task flags (PF_*), defined further below: */
762 	unsigned int			flags;
763 	unsigned int			ptrace;
764 
765 #ifdef CONFIG_SMP
766 	int				on_cpu;
767 	struct __call_single_node	wake_entry;
768 	unsigned int			wakee_flips;
769 	unsigned long			wakee_flip_decay_ts;
770 	struct task_struct		*last_wakee;
771 
772 	/*
773 	 * recent_used_cpu is initially set as the last CPU used by a task
774 	 * that wakes affine another task. Waker/wakee relationships can
775 	 * push tasks around a CPU where each wakeup moves to the next one.
776 	 * Tracking a recently used CPU allows a quick search for a recently
777 	 * used CPU that may be idle.
778 	 */
779 	int				recent_used_cpu;
780 	int				wake_cpu;
781 #endif
782 	int				on_rq;
783 
784 	int				prio;
785 	int				static_prio;
786 	int				normal_prio;
787 	unsigned int			rt_priority;
788 
789 	struct sched_entity		se;
790 	struct sched_rt_entity		rt;
791 	struct sched_dl_entity		dl;
792 	struct sched_dl_entity		*dl_server;
793 	const struct sched_class	*sched_class;
794 
795 #ifdef CONFIG_SCHED_CORE
796 	struct rb_node			core_node;
797 	unsigned long			core_cookie;
798 	unsigned int			core_occupation;
799 #endif
800 
801 #ifdef CONFIG_CGROUP_SCHED
802 	struct task_group		*sched_task_group;
803 #endif
804 
805 #ifdef CONFIG_UCLAMP_TASK
806 	/*
807 	 * Clamp values requested for a scheduling entity.
808 	 * Must be updated with task_rq_lock() held.
809 	 */
810 	struct uclamp_se		uclamp_req[UCLAMP_CNT];
811 	/*
812 	 * Effective clamp values used for a scheduling entity.
813 	 * Must be updated with task_rq_lock() held.
814 	 */
815 	struct uclamp_se		uclamp[UCLAMP_CNT];
816 #endif
817 
818 	struct sched_statistics         stats;
819 
820 #ifdef CONFIG_PREEMPT_NOTIFIERS
821 	/* List of struct preempt_notifier: */
822 	struct hlist_head		preempt_notifiers;
823 #endif
824 
825 #ifdef CONFIG_BLK_DEV_IO_TRACE
826 	unsigned int			btrace_seq;
827 #endif
828 
829 	unsigned int			policy;
830 	int				nr_cpus_allowed;
831 	const cpumask_t			*cpus_ptr;
832 	cpumask_t			*user_cpus_ptr;
833 	cpumask_t			cpus_mask;
834 	void				*migration_pending;
835 #ifdef CONFIG_SMP
836 	unsigned short			migration_disabled;
837 #endif
838 	unsigned short			migration_flags;
839 
840 #ifdef CONFIG_PREEMPT_RCU
841 	int				rcu_read_lock_nesting;
842 	union rcu_special		rcu_read_unlock_special;
843 	struct list_head		rcu_node_entry;
844 	struct rcu_node			*rcu_blocked_node;
845 #endif /* #ifdef CONFIG_PREEMPT_RCU */
846 
847 #ifdef CONFIG_TASKS_RCU
848 	unsigned long			rcu_tasks_nvcsw;
849 	u8				rcu_tasks_holdout;
850 	u8				rcu_tasks_idx;
851 	int				rcu_tasks_idle_cpu;
852 	struct list_head		rcu_tasks_holdout_list;
853 #endif /* #ifdef CONFIG_TASKS_RCU */
854 
855 #ifdef CONFIG_TASKS_TRACE_RCU
856 	int				trc_reader_nesting;
857 	int				trc_ipi_to_cpu;
858 	union rcu_special		trc_reader_special;
859 	struct list_head		trc_holdout_list;
860 	struct list_head		trc_blkd_node;
861 	int				trc_blkd_cpu;
862 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
863 
864 	struct sched_info		sched_info;
865 
866 	struct list_head		tasks;
867 #ifdef CONFIG_SMP
868 	struct plist_node		pushable_tasks;
869 	struct rb_node			pushable_dl_tasks;
870 #endif
871 
872 	struct mm_struct		*mm;
873 	struct mm_struct		*active_mm;
874 	struct address_space		*faults_disabled_mapping;
875 
876 	int				exit_state;
877 	int				exit_code;
878 	int				exit_signal;
879 	/* The signal sent when the parent dies: */
880 	int				pdeath_signal;
881 	/* JOBCTL_*, siglock protected: */
882 	unsigned long			jobctl;
883 
884 	/* Used for emulating ABI behavior of previous Linux versions: */
885 	unsigned int			personality;
886 
887 	/* Scheduler bits, serialized by scheduler locks: */
888 	unsigned			sched_reset_on_fork:1;
889 	unsigned			sched_contributes_to_load:1;
890 	unsigned			sched_migrated:1;
891 
892 	/* Force alignment to the next boundary: */
893 	unsigned			:0;
894 
895 	/* Unserialized, strictly 'current' */
896 
897 	/*
898 	 * This field must not be in the scheduler word above due to wakelist
899 	 * queueing no longer being serialized by p->on_cpu. However:
900 	 *
901 	 * p->XXX = X;			ttwu()
902 	 * schedule()			  if (p->on_rq && ..) // false
903 	 *   smp_mb__after_spinlock();	  if (smp_load_acquire(&p->on_cpu) && //true
904 	 *   deactivate_task()		      ttwu_queue_wakelist())
905 	 *     p->on_rq = 0;			p->sched_remote_wakeup = Y;
906 	 *
907 	 * guarantees all stores of 'current' are visible before
908 	 * ->sched_remote_wakeup gets used, so it can be in this word.
909 	 */
910 	unsigned			sched_remote_wakeup:1;
911 #ifdef CONFIG_RT_MUTEXES
912 	unsigned			sched_rt_mutex:1;
913 #endif
914 
915 	/* Bit to tell LSMs we're in execve(): */
916 	unsigned			in_execve:1;
917 	unsigned			in_iowait:1;
918 #ifndef TIF_RESTORE_SIGMASK
919 	unsigned			restore_sigmask:1;
920 #endif
921 #ifdef CONFIG_MEMCG
922 	unsigned			in_user_fault:1;
923 #endif
924 #ifdef CONFIG_LRU_GEN
925 	/* whether the LRU algorithm may apply to this access */
926 	unsigned			in_lru_fault:1;
927 #endif
928 #ifdef CONFIG_COMPAT_BRK
929 	unsigned			brk_randomized:1;
930 #endif
931 #ifdef CONFIG_CGROUPS
932 	/* disallow userland-initiated cgroup migration */
933 	unsigned			no_cgroup_migration:1;
934 	/* task is frozen/stopped (used by the cgroup freezer) */
935 	unsigned			frozen:1;
936 #endif
937 #ifdef CONFIG_BLK_CGROUP
938 	unsigned			use_memdelay:1;
939 #endif
940 #ifdef CONFIG_PSI
941 	/* Stalled due to lack of memory */
942 	unsigned			in_memstall:1;
943 #endif
944 #ifdef CONFIG_PAGE_OWNER
945 	/* Used by page_owner=on to detect recursion in page tracking. */
946 	unsigned			in_page_owner:1;
947 #endif
948 #ifdef CONFIG_EVENTFD
949 	/* Recursion prevention for eventfd_signal() */
950 	unsigned			in_eventfd:1;
951 #endif
952 #ifdef CONFIG_IOMMU_SVA
953 	unsigned			pasid_activated:1;
954 #endif
955 #ifdef	CONFIG_CPU_SUP_INTEL
956 	unsigned			reported_split_lock:1;
957 #endif
958 #ifdef CONFIG_TASK_DELAY_ACCT
959 	/* delay due to memory thrashing */
960 	unsigned                        in_thrashing:1;
961 #endif
962 
963 	unsigned long			atomic_flags; /* Flags requiring atomic access. */
964 
965 	struct restart_block		restart_block;
966 
967 	pid_t				pid;
968 	pid_t				tgid;
969 
970 #ifdef CONFIG_STACKPROTECTOR
971 	/* Canary value for the -fstack-protector GCC feature: */
972 	unsigned long			stack_canary;
973 #endif
974 	/*
975 	 * Pointers to the (original) parent process, youngest child, younger sibling,
976 	 * older sibling, respectively.  (p->father can be replaced with
977 	 * p->real_parent->pid)
978 	 */
979 
980 	/* Real parent process: */
981 	struct task_struct __rcu	*real_parent;
982 
983 	/* Recipient of SIGCHLD, wait4() reports: */
984 	struct task_struct __rcu	*parent;
985 
986 	/*
987 	 * Children/sibling form the list of natural children:
988 	 */
989 	struct list_head		children;
990 	struct list_head		sibling;
991 	struct task_struct		*group_leader;
992 
993 	/*
994 	 * 'ptraced' is the list of tasks this task is using ptrace() on.
995 	 *
996 	 * This includes both natural children and PTRACE_ATTACH targets.
997 	 * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
998 	 */
999 	struct list_head		ptraced;
1000 	struct list_head		ptrace_entry;
1001 
1002 	/* PID/PID hash table linkage. */
1003 	struct pid			*thread_pid;
1004 	struct hlist_node		pid_links[PIDTYPE_MAX];
1005 	struct list_head		thread_node;
1006 
1007 	struct completion		*vfork_done;
1008 
1009 	/* CLONE_CHILD_SETTID: */
1010 	int __user			*set_child_tid;
1011 
1012 	/* CLONE_CHILD_CLEARTID: */
1013 	int __user			*clear_child_tid;
1014 
1015 	/* PF_KTHREAD | PF_IO_WORKER */
1016 	void				*worker_private;
1017 
1018 	u64				utime;
1019 	u64				stime;
1020 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
1021 	u64				utimescaled;
1022 	u64				stimescaled;
1023 #endif
1024 	u64				gtime;
1025 	struct prev_cputime		prev_cputime;
1026 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1027 	struct vtime			vtime;
1028 #endif
1029 
1030 #ifdef CONFIG_NO_HZ_FULL
1031 	atomic_t			tick_dep_mask;
1032 #endif
1033 	/* Context switch counts: */
1034 	unsigned long			nvcsw;
1035 	unsigned long			nivcsw;
1036 
1037 	/* Monotonic time in nsecs: */
1038 	u64				start_time;
1039 
1040 	/* Boot based time in nsecs: */
1041 	u64				start_boottime;
1042 
1043 	/* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
1044 	unsigned long			min_flt;
1045 	unsigned long			maj_flt;
1046 
1047 	/* Empty if CONFIG_POSIX_CPUTIMERS=n */
1048 	struct posix_cputimers		posix_cputimers;
1049 
1050 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK
1051 	struct posix_cputimers_work	posix_cputimers_work;
1052 #endif
1053 
1054 	/* Process credentials: */
1055 
1056 	/* Tracer's credentials at attach: */
1057 	const struct cred __rcu		*ptracer_cred;
1058 
1059 	/* Objective and real subjective task credentials (COW): */
1060 	const struct cred __rcu		*real_cred;
1061 
1062 	/* Effective (overridable) subjective task credentials (COW): */
1063 	const struct cred __rcu		*cred;
1064 
1065 #ifdef CONFIG_KEYS
1066 	/* Cached requested key. */
1067 	struct key			*cached_requested_key;
1068 #endif
1069 
1070 	/*
1071 	 * executable name, excluding path.
1072 	 *
1073 	 * - normally initialized setup_new_exec()
1074 	 * - access it with [gs]et_task_comm()
1075 	 * - lock it with task_lock()
1076 	 */
1077 	char				comm[TASK_COMM_LEN];
1078 
1079 	struct nameidata		*nameidata;
1080 
1081 #ifdef CONFIG_SYSVIPC
1082 	struct sysv_sem			sysvsem;
1083 	struct sysv_shm			sysvshm;
1084 #endif
1085 #ifdef CONFIG_DETECT_HUNG_TASK
1086 	unsigned long			last_switch_count;
1087 	unsigned long			last_switch_time;
1088 #endif
1089 	/* Filesystem information: */
1090 	struct fs_struct		*fs;
1091 
1092 	/* Open file information: */
1093 	struct files_struct		*files;
1094 
1095 #ifdef CONFIG_IO_URING
1096 	struct io_uring_task		*io_uring;
1097 #endif
1098 
1099 	/* Namespaces: */
1100 	struct nsproxy			*nsproxy;
1101 
1102 	/* Signal handlers: */
1103 	struct signal_struct		*signal;
1104 	struct sighand_struct __rcu		*sighand;
1105 	sigset_t			blocked;
1106 	sigset_t			real_blocked;
1107 	/* Restored if set_restore_sigmask() was used: */
1108 	sigset_t			saved_sigmask;
1109 	struct sigpending		pending;
1110 	unsigned long			sas_ss_sp;
1111 	size_t				sas_ss_size;
1112 	unsigned int			sas_ss_flags;
1113 
1114 	struct callback_head		*task_works;
1115 
1116 #ifdef CONFIG_AUDIT
1117 #ifdef CONFIG_AUDITSYSCALL
1118 	struct audit_context		*audit_context;
1119 #endif
1120 	kuid_t				loginuid;
1121 	unsigned int			sessionid;
1122 #endif
1123 	struct seccomp			seccomp;
1124 	struct syscall_user_dispatch	syscall_dispatch;
1125 
1126 	/* Thread group tracking: */
1127 	u64				parent_exec_id;
1128 	u64				self_exec_id;
1129 
1130 	/* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
1131 	spinlock_t			alloc_lock;
1132 
1133 	/* Protection of the PI data structures: */
1134 	raw_spinlock_t			pi_lock;
1135 
1136 	struct wake_q_node		wake_q;
1137 
1138 #ifdef CONFIG_RT_MUTEXES
1139 	/* PI waiters blocked on a rt_mutex held by this task: */
1140 	struct rb_root_cached		pi_waiters;
1141 	/* Updated under owner's pi_lock and rq lock */
1142 	struct task_struct		*pi_top_task;
1143 	/* Deadlock detection and priority inheritance handling: */
1144 	struct rt_mutex_waiter		*pi_blocked_on;
1145 #endif
1146 
1147 #ifdef CONFIG_DEBUG_MUTEXES
1148 	/* Mutex deadlock detection: */
1149 	struct mutex_waiter		*blocked_on;
1150 #endif
1151 
1152 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1153 	int				non_block_count;
1154 #endif
1155 
1156 #ifdef CONFIG_TRACE_IRQFLAGS
1157 	struct irqtrace_events		irqtrace;
1158 	unsigned int			hardirq_threaded;
1159 	u64				hardirq_chain_key;
1160 	int				softirqs_enabled;
1161 	int				softirq_context;
1162 	int				irq_config;
1163 #endif
1164 #ifdef CONFIG_PREEMPT_RT
1165 	int				softirq_disable_cnt;
1166 #endif
1167 
1168 #ifdef CONFIG_LOCKDEP
1169 # define MAX_LOCK_DEPTH			48UL
1170 	u64				curr_chain_key;
1171 	int				lockdep_depth;
1172 	unsigned int			lockdep_recursion;
1173 	struct held_lock		held_locks[MAX_LOCK_DEPTH];
1174 #endif
1175 
1176 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP)
1177 	unsigned int			in_ubsan;
1178 #endif
1179 
1180 	/* Journalling filesystem info: */
1181 	void				*journal_info;
1182 
1183 	/* Stacked block device info: */
1184 	struct bio_list			*bio_list;
1185 
1186 	/* Stack plugging: */
1187 	struct blk_plug			*plug;
1188 
1189 	/* VM state: */
1190 	struct reclaim_state		*reclaim_state;
1191 
1192 	struct io_context		*io_context;
1193 
1194 #ifdef CONFIG_COMPACTION
1195 	struct capture_control		*capture_control;
1196 #endif
1197 	/* Ptrace state: */
1198 	unsigned long			ptrace_message;
1199 	kernel_siginfo_t		*last_siginfo;
1200 
1201 	struct task_io_accounting	ioac;
1202 #ifdef CONFIG_PSI
1203 	/* Pressure stall state */
1204 	unsigned int			psi_flags;
1205 #endif
1206 #ifdef CONFIG_TASK_XACCT
1207 	/* Accumulated RSS usage: */
1208 	u64				acct_rss_mem1;
1209 	/* Accumulated virtual memory usage: */
1210 	u64				acct_vm_mem1;
1211 	/* stime + utime since last update: */
1212 	u64				acct_timexpd;
1213 #endif
1214 #ifdef CONFIG_CPUSETS
1215 	/* Protected by ->alloc_lock: */
1216 	nodemask_t			mems_allowed;
1217 	/* Sequence number to catch updates: */
1218 	seqcount_spinlock_t		mems_allowed_seq;
1219 	int				cpuset_mem_spread_rotor;
1220 	int				cpuset_slab_spread_rotor;
1221 #endif
1222 #ifdef CONFIG_CGROUPS
1223 	/* Control Group info protected by css_set_lock: */
1224 	struct css_set __rcu		*cgroups;
1225 	/* cg_list protected by css_set_lock and tsk->alloc_lock: */
1226 	struct list_head		cg_list;
1227 #endif
1228 #ifdef CONFIG_X86_CPU_RESCTRL
1229 	u32				closid;
1230 	u32				rmid;
1231 #endif
1232 #ifdef CONFIG_FUTEX
1233 	struct robust_list_head __user	*robust_list;
1234 #ifdef CONFIG_COMPAT
1235 	struct compat_robust_list_head __user *compat_robust_list;
1236 #endif
1237 	struct list_head		pi_state_list;
1238 	struct futex_pi_state		*pi_state_cache;
1239 	struct mutex			futex_exit_mutex;
1240 	unsigned int			futex_state;
1241 #endif
1242 #ifdef CONFIG_PERF_EVENTS
1243 	struct perf_event_context	*perf_event_ctxp;
1244 	struct mutex			perf_event_mutex;
1245 	struct list_head		perf_event_list;
1246 #endif
1247 #ifdef CONFIG_DEBUG_PREEMPT
1248 	unsigned long			preempt_disable_ip;
1249 #endif
1250 #ifdef CONFIG_NUMA
1251 	/* Protected by alloc_lock: */
1252 	struct mempolicy		*mempolicy;
1253 	short				il_prev;
1254 	short				pref_node_fork;
1255 #endif
1256 #ifdef CONFIG_NUMA_BALANCING
1257 	int				numa_scan_seq;
1258 	unsigned int			numa_scan_period;
1259 	unsigned int			numa_scan_period_max;
1260 	int				numa_preferred_nid;
1261 	unsigned long			numa_migrate_retry;
1262 	/* Migration stamp: */
1263 	u64				node_stamp;
1264 	u64				last_task_numa_placement;
1265 	u64				last_sum_exec_runtime;
1266 	struct callback_head		numa_work;
1267 
1268 	/*
1269 	 * This pointer is only modified for current in syscall and
1270 	 * pagefault context (and for tasks being destroyed), so it can be read
1271 	 * from any of the following contexts:
1272 	 *  - RCU read-side critical section
1273 	 *  - current->numa_group from everywhere
1274 	 *  - task's runqueue locked, task not running
1275 	 */
1276 	struct numa_group __rcu		*numa_group;
1277 
1278 	/*
1279 	 * numa_faults is an array split into four regions:
1280 	 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1281 	 * in this precise order.
1282 	 *
1283 	 * faults_memory: Exponential decaying average of faults on a per-node
1284 	 * basis. Scheduling placement decisions are made based on these
1285 	 * counts. The values remain static for the duration of a PTE scan.
1286 	 * faults_cpu: Track the nodes the process was running on when a NUMA
1287 	 * hinting fault was incurred.
1288 	 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1289 	 * during the current scan window. When the scan completes, the counts
1290 	 * in faults_memory and faults_cpu decay and these values are copied.
1291 	 */
1292 	unsigned long			*numa_faults;
1293 	unsigned long			total_numa_faults;
1294 
1295 	/*
1296 	 * numa_faults_locality tracks if faults recorded during the last
1297 	 * scan window were remote/local or failed to migrate. The task scan
1298 	 * period is adapted based on the locality of the faults with different
1299 	 * weights depending on whether they were shared or private faults
1300 	 */
1301 	unsigned long			numa_faults_locality[3];
1302 
1303 	unsigned long			numa_pages_migrated;
1304 #endif /* CONFIG_NUMA_BALANCING */
1305 
1306 #ifdef CONFIG_RSEQ
1307 	struct rseq __user *rseq;
1308 	u32 rseq_len;
1309 	u32 rseq_sig;
1310 	/*
1311 	 * RmW on rseq_event_mask must be performed atomically
1312 	 * with respect to preemption.
1313 	 */
1314 	unsigned long rseq_event_mask;
1315 #endif
1316 
1317 #ifdef CONFIG_SCHED_MM_CID
1318 	int				mm_cid;		/* Current cid in mm */
1319 	int				last_mm_cid;	/* Most recent cid in mm */
1320 	int				migrate_from_cpu;
1321 	int				mm_cid_active;	/* Whether cid bitmap is active */
1322 	struct callback_head		cid_work;
1323 #endif
1324 
1325 	struct tlbflush_unmap_batch	tlb_ubc;
1326 
1327 	/* Cache last used pipe for splice(): */
1328 	struct pipe_inode_info		*splice_pipe;
1329 
1330 	struct page_frag		task_frag;
1331 
1332 #ifdef CONFIG_TASK_DELAY_ACCT
1333 	struct task_delay_info		*delays;
1334 #endif
1335 
1336 #ifdef CONFIG_FAULT_INJECTION
1337 	int				make_it_fail;
1338 	unsigned int			fail_nth;
1339 #endif
1340 	/*
1341 	 * When (nr_dirtied >= nr_dirtied_pause), it's time to call
1342 	 * balance_dirty_pages() for a dirty throttling pause:
1343 	 */
1344 	int				nr_dirtied;
1345 	int				nr_dirtied_pause;
1346 	/* Start of a write-and-pause period: */
1347 	unsigned long			dirty_paused_when;
1348 
1349 #ifdef CONFIG_LATENCYTOP
1350 	int				latency_record_count;
1351 	struct latency_record		latency_record[LT_SAVECOUNT];
1352 #endif
1353 	/*
1354 	 * Time slack values; these are used to round up poll() and
1355 	 * select() etc timeout values. These are in nanoseconds.
1356 	 */
1357 	u64				timer_slack_ns;
1358 	u64				default_timer_slack_ns;
1359 
1360 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
1361 	unsigned int			kasan_depth;
1362 #endif
1363 
1364 #ifdef CONFIG_KCSAN
1365 	struct kcsan_ctx		kcsan_ctx;
1366 #ifdef CONFIG_TRACE_IRQFLAGS
1367 	struct irqtrace_events		kcsan_save_irqtrace;
1368 #endif
1369 #ifdef CONFIG_KCSAN_WEAK_MEMORY
1370 	int				kcsan_stack_depth;
1371 #endif
1372 #endif
1373 
1374 #ifdef CONFIG_KMSAN
1375 	struct kmsan_ctx		kmsan_ctx;
1376 #endif
1377 
1378 #if IS_ENABLED(CONFIG_KUNIT)
1379 	struct kunit			*kunit_test;
1380 #endif
1381 
1382 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1383 	/* Index of current stored address in ret_stack: */
1384 	int				curr_ret_stack;
1385 	int				curr_ret_depth;
1386 
1387 	/* Stack of return addresses for return function tracing: */
1388 	struct ftrace_ret_stack		*ret_stack;
1389 
1390 	/* Timestamp for last schedule: */
1391 	unsigned long long		ftrace_timestamp;
1392 
1393 	/*
1394 	 * Number of functions that haven't been traced
1395 	 * because of depth overrun:
1396 	 */
1397 	atomic_t			trace_overrun;
1398 
1399 	/* Pause tracing: */
1400 	atomic_t			tracing_graph_pause;
1401 #endif
1402 
1403 #ifdef CONFIG_TRACING
1404 	/* Bitmask and counter of trace recursion: */
1405 	unsigned long			trace_recursion;
1406 #endif /* CONFIG_TRACING */
1407 
1408 #ifdef CONFIG_KCOV
1409 	/* See kernel/kcov.c for more details. */
1410 
1411 	/* Coverage collection mode enabled for this task (0 if disabled): */
1412 	unsigned int			kcov_mode;
1413 
1414 	/* Size of the kcov_area: */
1415 	unsigned int			kcov_size;
1416 
1417 	/* Buffer for coverage collection: */
1418 	void				*kcov_area;
1419 
1420 	/* KCOV descriptor wired with this task or NULL: */
1421 	struct kcov			*kcov;
1422 
1423 	/* KCOV common handle for remote coverage collection: */
1424 	u64				kcov_handle;
1425 
1426 	/* KCOV sequence number: */
1427 	int				kcov_sequence;
1428 
1429 	/* Collect coverage from softirq context: */
1430 	unsigned int			kcov_softirq;
1431 #endif
1432 
1433 #ifdef CONFIG_MEMCG
1434 	struct mem_cgroup		*memcg_in_oom;
1435 	gfp_t				memcg_oom_gfp_mask;
1436 	int				memcg_oom_order;
1437 
1438 	/* Number of pages to reclaim on returning to userland: */
1439 	unsigned int			memcg_nr_pages_over_high;
1440 
1441 	/* Used by memcontrol for targeted memcg charge: */
1442 	struct mem_cgroup		*active_memcg;
1443 #endif
1444 
1445 #ifdef CONFIG_MEMCG_KMEM
1446 	struct obj_cgroup		*objcg;
1447 #endif
1448 
1449 #ifdef CONFIG_BLK_CGROUP
1450 	struct gendisk			*throttle_disk;
1451 #endif
1452 
1453 #ifdef CONFIG_UPROBES
1454 	struct uprobe_task		*utask;
1455 #endif
1456 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1457 	unsigned int			sequential_io;
1458 	unsigned int			sequential_io_avg;
1459 #endif
1460 	struct kmap_ctrl		kmap_ctrl;
1461 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1462 	unsigned long			task_state_change;
1463 # ifdef CONFIG_PREEMPT_RT
1464 	unsigned long			saved_state_change;
1465 # endif
1466 #endif
1467 	struct rcu_head			rcu;
1468 	refcount_t			rcu_users;
1469 	int				pagefault_disabled;
1470 #ifdef CONFIG_MMU
1471 	struct task_struct		*oom_reaper_list;
1472 	struct timer_list		oom_reaper_timer;
1473 #endif
1474 #ifdef CONFIG_VMAP_STACK
1475 	struct vm_struct		*stack_vm_area;
1476 #endif
1477 #ifdef CONFIG_THREAD_INFO_IN_TASK
1478 	/* A live task holds one reference: */
1479 	refcount_t			stack_refcount;
1480 #endif
1481 #ifdef CONFIG_LIVEPATCH
1482 	int patch_state;
1483 #endif
1484 #ifdef CONFIG_SECURITY
1485 	/* Used by LSM modules for access restriction: */
1486 	void				*security;
1487 #endif
1488 #ifdef CONFIG_BPF_SYSCALL
1489 	/* Used by BPF task local storage */
1490 	struct bpf_local_storage __rcu	*bpf_storage;
1491 	/* Used for BPF run context */
1492 	struct bpf_run_ctx		*bpf_ctx;
1493 #endif
1494 
1495 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK
1496 	unsigned long			lowest_stack;
1497 	unsigned long			prev_lowest_stack;
1498 #endif
1499 
1500 #ifdef CONFIG_X86_MCE
1501 	void __user			*mce_vaddr;
1502 	__u64				mce_kflags;
1503 	u64				mce_addr;
1504 	__u64				mce_ripv : 1,
1505 					mce_whole_page : 1,
1506 					__mce_reserved : 62;
1507 	struct callback_head		mce_kill_me;
1508 	int				mce_count;
1509 #endif
1510 
1511 #ifdef CONFIG_KRETPROBES
1512 	struct llist_head               kretprobe_instances;
1513 #endif
1514 #ifdef CONFIG_RETHOOK
1515 	struct llist_head               rethooks;
1516 #endif
1517 
1518 #ifdef CONFIG_ARCH_HAS_PARANOID_L1D_FLUSH
1519 	/*
1520 	 * If L1D flush is supported on mm context switch
1521 	 * then we use this callback head to queue kill work
1522 	 * to kill tasks that are not running on SMT disabled
1523 	 * cores
1524 	 */
1525 	struct callback_head		l1d_flush_kill;
1526 #endif
1527 
1528 #ifdef CONFIG_RV
1529 	/*
1530 	 * Per-task RV monitor. Nowadays fixed in RV_PER_TASK_MONITORS.
1531 	 * If we find justification for more monitors, we can think
1532 	 * about adding more or developing a dynamic method. So far,
1533 	 * none of these are justified.
1534 	 */
1535 	union rv_task_monitor		rv[RV_PER_TASK_MONITORS];
1536 #endif
1537 
1538 #ifdef CONFIG_USER_EVENTS
1539 	struct user_event_mm		*user_event_mm;
1540 #endif
1541 
1542 	/*
1543 	 * New fields for task_struct should be added above here, so that
1544 	 * they are included in the randomized portion of task_struct.
1545 	 */
1546 	randomized_struct_fields_end
1547 
1548 	/* CPU-specific state of this task: */
1549 	struct thread_struct		thread;
1550 
1551 	/*
1552 	 * WARNING: on x86, 'thread_struct' contains a variable-sized
1553 	 * structure.  It *MUST* be at the end of 'task_struct'.
1554 	 *
1555 	 * Do not put anything below here!
1556 	 */
1557 };
1558 
1559 static inline struct pid *task_pid(struct task_struct *task)
1560 {
1561 	return task->thread_pid;
1562 }
1563 
1564 /*
1565  * the helpers to get the task's different pids as they are seen
1566  * from various namespaces
1567  *
1568  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1569  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1570  *                     current.
1571  * task_xid_nr_ns()  : id seen from the ns specified;
1572  *
1573  * see also pid_nr() etc in include/linux/pid.h
1574  */
1575 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns);
1576 
1577 static inline pid_t task_pid_nr(struct task_struct *tsk)
1578 {
1579 	return tsk->pid;
1580 }
1581 
1582 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1583 {
1584 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1585 }
1586 
1587 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1588 {
1589 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1590 }
1591 
1592 
1593 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1594 {
1595 	return tsk->tgid;
1596 }
1597 
1598 /**
1599  * pid_alive - check that a task structure is not stale
1600  * @p: Task structure to be checked.
1601  *
1602  * Test if a process is not yet dead (at most zombie state)
1603  * If pid_alive fails, then pointers within the task structure
1604  * can be stale and must not be dereferenced.
1605  *
1606  * Return: 1 if the process is alive. 0 otherwise.
1607  */
1608 static inline int pid_alive(const struct task_struct *p)
1609 {
1610 	return p->thread_pid != NULL;
1611 }
1612 
1613 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1614 {
1615 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1616 }
1617 
1618 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1619 {
1620 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1621 }
1622 
1623 
1624 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1625 {
1626 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1627 }
1628 
1629 static inline pid_t task_session_vnr(struct task_struct *tsk)
1630 {
1631 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1632 }
1633 
1634 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1635 {
1636 	return __task_pid_nr_ns(tsk, PIDTYPE_TGID, ns);
1637 }
1638 
1639 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1640 {
1641 	return __task_pid_nr_ns(tsk, PIDTYPE_TGID, NULL);
1642 }
1643 
1644 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1645 {
1646 	pid_t pid = 0;
1647 
1648 	rcu_read_lock();
1649 	if (pid_alive(tsk))
1650 		pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1651 	rcu_read_unlock();
1652 
1653 	return pid;
1654 }
1655 
1656 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1657 {
1658 	return task_ppid_nr_ns(tsk, &init_pid_ns);
1659 }
1660 
1661 /* Obsolete, do not use: */
1662 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1663 {
1664 	return task_pgrp_nr_ns(tsk, &init_pid_ns);
1665 }
1666 
1667 #define TASK_REPORT_IDLE	(TASK_REPORT + 1)
1668 #define TASK_REPORT_MAX		(TASK_REPORT_IDLE << 1)
1669 
1670 static inline unsigned int __task_state_index(unsigned int tsk_state,
1671 					      unsigned int tsk_exit_state)
1672 {
1673 	unsigned int state = (tsk_state | tsk_exit_state) & TASK_REPORT;
1674 
1675 	BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX);
1676 
1677 	if ((tsk_state & TASK_IDLE) == TASK_IDLE)
1678 		state = TASK_REPORT_IDLE;
1679 
1680 	/*
1681 	 * We're lying here, but rather than expose a completely new task state
1682 	 * to userspace, we can make this appear as if the task has gone through
1683 	 * a regular rt_mutex_lock() call.
1684 	 */
1685 	if (tsk_state & TASK_RTLOCK_WAIT)
1686 		state = TASK_UNINTERRUPTIBLE;
1687 
1688 	return fls(state);
1689 }
1690 
1691 static inline unsigned int task_state_index(struct task_struct *tsk)
1692 {
1693 	return __task_state_index(READ_ONCE(tsk->__state), tsk->exit_state);
1694 }
1695 
1696 static inline char task_index_to_char(unsigned int state)
1697 {
1698 	static const char state_char[] = "RSDTtXZPI";
1699 
1700 	BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1);
1701 
1702 	return state_char[state];
1703 }
1704 
1705 static inline char task_state_to_char(struct task_struct *tsk)
1706 {
1707 	return task_index_to_char(task_state_index(tsk));
1708 }
1709 
1710 /**
1711  * is_global_init - check if a task structure is init. Since init
1712  * is free to have sub-threads we need to check tgid.
1713  * @tsk: Task structure to be checked.
1714  *
1715  * Check if a task structure is the first user space task the kernel created.
1716  *
1717  * Return: 1 if the task structure is init. 0 otherwise.
1718  */
1719 static inline int is_global_init(struct task_struct *tsk)
1720 {
1721 	return task_tgid_nr(tsk) == 1;
1722 }
1723 
1724 extern struct pid *cad_pid;
1725 
1726 /*
1727  * Per process flags
1728  */
1729 #define PF_VCPU			0x00000001	/* I'm a virtual CPU */
1730 #define PF_IDLE			0x00000002	/* I am an IDLE thread */
1731 #define PF_EXITING		0x00000004	/* Getting shut down */
1732 #define PF_POSTCOREDUMP		0x00000008	/* Coredumps should ignore this task */
1733 #define PF_IO_WORKER		0x00000010	/* Task is an IO worker */
1734 #define PF_WQ_WORKER		0x00000020	/* I'm a workqueue worker */
1735 #define PF_FORKNOEXEC		0x00000040	/* Forked but didn't exec */
1736 #define PF_MCE_PROCESS		0x00000080      /* Process policy on mce errors */
1737 #define PF_SUPERPRIV		0x00000100	/* Used super-user privileges */
1738 #define PF_DUMPCORE		0x00000200	/* Dumped core */
1739 #define PF_SIGNALED		0x00000400	/* Killed by a signal */
1740 #define PF_MEMALLOC		0x00000800	/* Allocating memory */
1741 #define PF_NPROC_EXCEEDED	0x00001000	/* set_user() noticed that RLIMIT_NPROC was exceeded */
1742 #define PF_USED_MATH		0x00002000	/* If unset the fpu must be initialized before use */
1743 #define PF_USER_WORKER		0x00004000	/* Kernel thread cloned from userspace thread */
1744 #define PF_NOFREEZE		0x00008000	/* This thread should not be frozen */
1745 #define PF__HOLE__00010000	0x00010000
1746 #define PF_KSWAPD		0x00020000	/* I am kswapd */
1747 #define PF_MEMALLOC_NOFS	0x00040000	/* All allocation requests will inherit GFP_NOFS */
1748 #define PF_MEMALLOC_NOIO	0x00080000	/* All allocation requests will inherit GFP_NOIO */
1749 #define PF_LOCAL_THROTTLE	0x00100000	/* Throttle writes only against the bdi I write to,
1750 						 * I am cleaning dirty pages from some other bdi. */
1751 #define PF_KTHREAD		0x00200000	/* I am a kernel thread */
1752 #define PF_RANDOMIZE		0x00400000	/* Randomize virtual address space */
1753 #define PF__HOLE__00800000	0x00800000
1754 #define PF__HOLE__01000000	0x01000000
1755 #define PF__HOLE__02000000	0x02000000
1756 #define PF_NO_SETAFFINITY	0x04000000	/* Userland is not allowed to meddle with cpus_mask */
1757 #define PF_MCE_EARLY		0x08000000      /* Early kill for mce process policy */
1758 #define PF_MEMALLOC_PIN		0x10000000	/* Allocation context constrained to zones which allow long term pinning. */
1759 #define PF__HOLE__20000000	0x20000000
1760 #define PF__HOLE__40000000	0x40000000
1761 #define PF_SUSPEND_TASK		0x80000000      /* This thread called freeze_processes() and should not be frozen */
1762 
1763 /*
1764  * Only the _current_ task can read/write to tsk->flags, but other
1765  * tasks can access tsk->flags in readonly mode for example
1766  * with tsk_used_math (like during threaded core dumping).
1767  * There is however an exception to this rule during ptrace
1768  * or during fork: the ptracer task is allowed to write to the
1769  * child->flags of its traced child (same goes for fork, the parent
1770  * can write to the child->flags), because we're guaranteed the
1771  * child is not running and in turn not changing child->flags
1772  * at the same time the parent does it.
1773  */
1774 #define clear_stopped_child_used_math(child)	do { (child)->flags &= ~PF_USED_MATH; } while (0)
1775 #define set_stopped_child_used_math(child)	do { (child)->flags |= PF_USED_MATH; } while (0)
1776 #define clear_used_math()			clear_stopped_child_used_math(current)
1777 #define set_used_math()				set_stopped_child_used_math(current)
1778 
1779 #define conditional_stopped_child_used_math(condition, child) \
1780 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1781 
1782 #define conditional_used_math(condition)	conditional_stopped_child_used_math(condition, current)
1783 
1784 #define copy_to_stopped_child_used_math(child) \
1785 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1786 
1787 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1788 #define tsk_used_math(p)			((p)->flags & PF_USED_MATH)
1789 #define used_math()				tsk_used_math(current)
1790 
1791 static __always_inline bool is_percpu_thread(void)
1792 {
1793 #ifdef CONFIG_SMP
1794 	return (current->flags & PF_NO_SETAFFINITY) &&
1795 		(current->nr_cpus_allowed  == 1);
1796 #else
1797 	return true;
1798 #endif
1799 }
1800 
1801 /* Per-process atomic flags. */
1802 #define PFA_NO_NEW_PRIVS		0	/* May not gain new privileges. */
1803 #define PFA_SPREAD_PAGE			1	/* Spread page cache over cpuset */
1804 #define PFA_SPREAD_SLAB			2	/* Spread some slab caches over cpuset */
1805 #define PFA_SPEC_SSB_DISABLE		3	/* Speculative Store Bypass disabled */
1806 #define PFA_SPEC_SSB_FORCE_DISABLE	4	/* Speculative Store Bypass force disabled*/
1807 #define PFA_SPEC_IB_DISABLE		5	/* Indirect branch speculation restricted */
1808 #define PFA_SPEC_IB_FORCE_DISABLE	6	/* Indirect branch speculation permanently restricted */
1809 #define PFA_SPEC_SSB_NOEXEC		7	/* Speculative Store Bypass clear on execve() */
1810 
1811 #define TASK_PFA_TEST(name, func)					\
1812 	static inline bool task_##func(struct task_struct *p)		\
1813 	{ return test_bit(PFA_##name, &p->atomic_flags); }
1814 
1815 #define TASK_PFA_SET(name, func)					\
1816 	static inline void task_set_##func(struct task_struct *p)	\
1817 	{ set_bit(PFA_##name, &p->atomic_flags); }
1818 
1819 #define TASK_PFA_CLEAR(name, func)					\
1820 	static inline void task_clear_##func(struct task_struct *p)	\
1821 	{ clear_bit(PFA_##name, &p->atomic_flags); }
1822 
1823 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
1824 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
1825 
1826 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
1827 TASK_PFA_SET(SPREAD_PAGE, spread_page)
1828 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
1829 
1830 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
1831 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
1832 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
1833 
1834 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable)
1835 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable)
1836 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable)
1837 
1838 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1839 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1840 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1841 
1842 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1843 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1844 
1845 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable)
1846 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable)
1847 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable)
1848 
1849 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1850 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1851 
1852 static inline void
1853 current_restore_flags(unsigned long orig_flags, unsigned long flags)
1854 {
1855 	current->flags &= ~flags;
1856 	current->flags |= orig_flags & flags;
1857 }
1858 
1859 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
1860 extern int task_can_attach(struct task_struct *p);
1861 extern int dl_bw_alloc(int cpu, u64 dl_bw);
1862 extern void dl_bw_free(int cpu, u64 dl_bw);
1863 #ifdef CONFIG_SMP
1864 
1865 /* do_set_cpus_allowed() - consider using set_cpus_allowed_ptr() instead */
1866 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
1867 
1868 /**
1869  * set_cpus_allowed_ptr - set CPU affinity mask of a task
1870  * @p: the task
1871  * @new_mask: CPU affinity mask
1872  *
1873  * Return: zero if successful, or a negative error code
1874  */
1875 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
1876 extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node);
1877 extern void release_user_cpus_ptr(struct task_struct *p);
1878 extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask);
1879 extern void force_compatible_cpus_allowed_ptr(struct task_struct *p);
1880 extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p);
1881 #else
1882 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
1883 {
1884 }
1885 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
1886 {
1887 	if (!cpumask_test_cpu(0, new_mask))
1888 		return -EINVAL;
1889 	return 0;
1890 }
1891 static inline int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node)
1892 {
1893 	if (src->user_cpus_ptr)
1894 		return -EINVAL;
1895 	return 0;
1896 }
1897 static inline void release_user_cpus_ptr(struct task_struct *p)
1898 {
1899 	WARN_ON(p->user_cpus_ptr);
1900 }
1901 
1902 static inline int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask)
1903 {
1904 	return 0;
1905 }
1906 #endif
1907 
1908 extern int yield_to(struct task_struct *p, bool preempt);
1909 extern void set_user_nice(struct task_struct *p, long nice);
1910 extern int task_prio(const struct task_struct *p);
1911 
1912 /**
1913  * task_nice - return the nice value of a given task.
1914  * @p: the task in question.
1915  *
1916  * Return: The nice value [ -20 ... 0 ... 19 ].
1917  */
1918 static inline int task_nice(const struct task_struct *p)
1919 {
1920 	return PRIO_TO_NICE((p)->static_prio);
1921 }
1922 
1923 extern int can_nice(const struct task_struct *p, const int nice);
1924 extern int task_curr(const struct task_struct *p);
1925 extern int idle_cpu(int cpu);
1926 extern int available_idle_cpu(int cpu);
1927 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *);
1928 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *);
1929 extern void sched_set_fifo(struct task_struct *p);
1930 extern void sched_set_fifo_low(struct task_struct *p);
1931 extern void sched_set_normal(struct task_struct *p, int nice);
1932 extern int sched_setattr(struct task_struct *, const struct sched_attr *);
1933 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *);
1934 extern struct task_struct *idle_task(int cpu);
1935 
1936 /**
1937  * is_idle_task - is the specified task an idle task?
1938  * @p: the task in question.
1939  *
1940  * Return: 1 if @p is an idle task. 0 otherwise.
1941  */
1942 static __always_inline bool is_idle_task(const struct task_struct *p)
1943 {
1944 	return !!(p->flags & PF_IDLE);
1945 }
1946 
1947 extern struct task_struct *curr_task(int cpu);
1948 extern void ia64_set_curr_task(int cpu, struct task_struct *p);
1949 
1950 void yield(void);
1951 
1952 union thread_union {
1953 	struct task_struct task;
1954 #ifndef CONFIG_THREAD_INFO_IN_TASK
1955 	struct thread_info thread_info;
1956 #endif
1957 	unsigned long stack[THREAD_SIZE/sizeof(long)];
1958 };
1959 
1960 #ifndef CONFIG_THREAD_INFO_IN_TASK
1961 extern struct thread_info init_thread_info;
1962 #endif
1963 
1964 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
1965 
1966 #ifdef CONFIG_THREAD_INFO_IN_TASK
1967 # define task_thread_info(task)	(&(task)->thread_info)
1968 #elif !defined(__HAVE_THREAD_FUNCTIONS)
1969 # define task_thread_info(task)	((struct thread_info *)(task)->stack)
1970 #endif
1971 
1972 /*
1973  * find a task by one of its numerical ids
1974  *
1975  * find_task_by_pid_ns():
1976  *      finds a task by its pid in the specified namespace
1977  * find_task_by_vpid():
1978  *      finds a task by its virtual pid
1979  *
1980  * see also find_vpid() etc in include/linux/pid.h
1981  */
1982 
1983 extern struct task_struct *find_task_by_vpid(pid_t nr);
1984 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns);
1985 
1986 /*
1987  * find a task by its virtual pid and get the task struct
1988  */
1989 extern struct task_struct *find_get_task_by_vpid(pid_t nr);
1990 
1991 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
1992 extern int wake_up_process(struct task_struct *tsk);
1993 extern void wake_up_new_task(struct task_struct *tsk);
1994 
1995 #ifdef CONFIG_SMP
1996 extern void kick_process(struct task_struct *tsk);
1997 #else
1998 static inline void kick_process(struct task_struct *tsk) { }
1999 #endif
2000 
2001 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
2002 
2003 static inline void set_task_comm(struct task_struct *tsk, const char *from)
2004 {
2005 	__set_task_comm(tsk, from, false);
2006 }
2007 
2008 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk);
2009 #define get_task_comm(buf, tsk) ({			\
2010 	BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN);	\
2011 	__get_task_comm(buf, sizeof(buf), tsk);		\
2012 })
2013 
2014 #ifdef CONFIG_SMP
2015 static __always_inline void scheduler_ipi(void)
2016 {
2017 	/*
2018 	 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting
2019 	 * TIF_NEED_RESCHED remotely (for the first time) will also send
2020 	 * this IPI.
2021 	 */
2022 	preempt_fold_need_resched();
2023 }
2024 #else
2025 static inline void scheduler_ipi(void) { }
2026 #endif
2027 
2028 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state);
2029 
2030 /*
2031  * Set thread flags in other task's structures.
2032  * See asm/thread_info.h for TIF_xxxx flags available:
2033  */
2034 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2035 {
2036 	set_ti_thread_flag(task_thread_info(tsk), flag);
2037 }
2038 
2039 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2040 {
2041 	clear_ti_thread_flag(task_thread_info(tsk), flag);
2042 }
2043 
2044 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag,
2045 					  bool value)
2046 {
2047 	update_ti_thread_flag(task_thread_info(tsk), flag, value);
2048 }
2049 
2050 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2051 {
2052 	return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2053 }
2054 
2055 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2056 {
2057 	return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2058 }
2059 
2060 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2061 {
2062 	return test_ti_thread_flag(task_thread_info(tsk), flag);
2063 }
2064 
2065 static inline void set_tsk_need_resched(struct task_struct *tsk)
2066 {
2067 	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2068 }
2069 
2070 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2071 {
2072 	clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2073 }
2074 
2075 static inline int test_tsk_need_resched(struct task_struct *tsk)
2076 {
2077 	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2078 }
2079 
2080 /*
2081  * cond_resched() and cond_resched_lock(): latency reduction via
2082  * explicit rescheduling in places that are safe. The return
2083  * value indicates whether a reschedule was done in fact.
2084  * cond_resched_lock() will drop the spinlock before scheduling,
2085  */
2086 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC)
2087 extern int __cond_resched(void);
2088 
2089 #if defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL)
2090 
2091 void sched_dynamic_klp_enable(void);
2092 void sched_dynamic_klp_disable(void);
2093 
2094 DECLARE_STATIC_CALL(cond_resched, __cond_resched);
2095 
2096 static __always_inline int _cond_resched(void)
2097 {
2098 	return static_call_mod(cond_resched)();
2099 }
2100 
2101 #elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY)
2102 
2103 extern int dynamic_cond_resched(void);
2104 
2105 static __always_inline int _cond_resched(void)
2106 {
2107 	return dynamic_cond_resched();
2108 }
2109 
2110 #else /* !CONFIG_PREEMPTION */
2111 
2112 static inline int _cond_resched(void)
2113 {
2114 	klp_sched_try_switch();
2115 	return __cond_resched();
2116 }
2117 
2118 #endif /* PREEMPT_DYNAMIC && CONFIG_HAVE_PREEMPT_DYNAMIC_CALL */
2119 
2120 #else /* CONFIG_PREEMPTION && !CONFIG_PREEMPT_DYNAMIC */
2121 
2122 static inline int _cond_resched(void)
2123 {
2124 	klp_sched_try_switch();
2125 	return 0;
2126 }
2127 
2128 #endif /* !CONFIG_PREEMPTION || CONFIG_PREEMPT_DYNAMIC */
2129 
2130 #define cond_resched() ({			\
2131 	__might_resched(__FILE__, __LINE__, 0);	\
2132 	_cond_resched();			\
2133 })
2134 
2135 extern int __cond_resched_lock(spinlock_t *lock);
2136 extern int __cond_resched_rwlock_read(rwlock_t *lock);
2137 extern int __cond_resched_rwlock_write(rwlock_t *lock);
2138 
2139 #define MIGHT_RESCHED_RCU_SHIFT		8
2140 #define MIGHT_RESCHED_PREEMPT_MASK	((1U << MIGHT_RESCHED_RCU_SHIFT) - 1)
2141 
2142 #ifndef CONFIG_PREEMPT_RT
2143 /*
2144  * Non RT kernels have an elevated preempt count due to the held lock,
2145  * but are not allowed to be inside a RCU read side critical section
2146  */
2147 # define PREEMPT_LOCK_RESCHED_OFFSETS	PREEMPT_LOCK_OFFSET
2148 #else
2149 /*
2150  * spin/rw_lock() on RT implies rcu_read_lock(). The might_sleep() check in
2151  * cond_resched*lock() has to take that into account because it checks for
2152  * preempt_count() and rcu_preempt_depth().
2153  */
2154 # define PREEMPT_LOCK_RESCHED_OFFSETS	\
2155 	(PREEMPT_LOCK_OFFSET + (1U << MIGHT_RESCHED_RCU_SHIFT))
2156 #endif
2157 
2158 #define cond_resched_lock(lock) ({						\
2159 	__might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS);	\
2160 	__cond_resched_lock(lock);						\
2161 })
2162 
2163 #define cond_resched_rwlock_read(lock) ({					\
2164 	__might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS);	\
2165 	__cond_resched_rwlock_read(lock);					\
2166 })
2167 
2168 #define cond_resched_rwlock_write(lock) ({					\
2169 	__might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS);	\
2170 	__cond_resched_rwlock_write(lock);					\
2171 })
2172 
2173 static inline void cond_resched_rcu(void)
2174 {
2175 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
2176 	rcu_read_unlock();
2177 	cond_resched();
2178 	rcu_read_lock();
2179 #endif
2180 }
2181 
2182 #ifdef CONFIG_PREEMPT_DYNAMIC
2183 
2184 extern bool preempt_model_none(void);
2185 extern bool preempt_model_voluntary(void);
2186 extern bool preempt_model_full(void);
2187 
2188 #else
2189 
2190 static inline bool preempt_model_none(void)
2191 {
2192 	return IS_ENABLED(CONFIG_PREEMPT_NONE);
2193 }
2194 static inline bool preempt_model_voluntary(void)
2195 {
2196 	return IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY);
2197 }
2198 static inline bool preempt_model_full(void)
2199 {
2200 	return IS_ENABLED(CONFIG_PREEMPT);
2201 }
2202 
2203 #endif
2204 
2205 static inline bool preempt_model_rt(void)
2206 {
2207 	return IS_ENABLED(CONFIG_PREEMPT_RT);
2208 }
2209 
2210 /*
2211  * Does the preemption model allow non-cooperative preemption?
2212  *
2213  * For !CONFIG_PREEMPT_DYNAMIC kernels this is an exact match with
2214  * CONFIG_PREEMPTION; for CONFIG_PREEMPT_DYNAMIC this doesn't work as the
2215  * kernel is *built* with CONFIG_PREEMPTION=y but may run with e.g. the
2216  * PREEMPT_NONE model.
2217  */
2218 static inline bool preempt_model_preemptible(void)
2219 {
2220 	return preempt_model_full() || preempt_model_rt();
2221 }
2222 
2223 /*
2224  * Does a critical section need to be broken due to another
2225  * task waiting?: (technically does not depend on CONFIG_PREEMPTION,
2226  * but a general need for low latency)
2227  */
2228 static inline int spin_needbreak(spinlock_t *lock)
2229 {
2230 #ifdef CONFIG_PREEMPTION
2231 	return spin_is_contended(lock);
2232 #else
2233 	return 0;
2234 #endif
2235 }
2236 
2237 /*
2238  * Check if a rwlock is contended.
2239  * Returns non-zero if there is another task waiting on the rwlock.
2240  * Returns zero if the lock is not contended or the system / underlying
2241  * rwlock implementation does not support contention detection.
2242  * Technically does not depend on CONFIG_PREEMPTION, but a general need
2243  * for low latency.
2244  */
2245 static inline int rwlock_needbreak(rwlock_t *lock)
2246 {
2247 #ifdef CONFIG_PREEMPTION
2248 	return rwlock_is_contended(lock);
2249 #else
2250 	return 0;
2251 #endif
2252 }
2253 
2254 static __always_inline bool need_resched(void)
2255 {
2256 	return unlikely(tif_need_resched());
2257 }
2258 
2259 /*
2260  * Wrappers for p->thread_info->cpu access. No-op on UP.
2261  */
2262 #ifdef CONFIG_SMP
2263 
2264 static inline unsigned int task_cpu(const struct task_struct *p)
2265 {
2266 	return READ_ONCE(task_thread_info(p)->cpu);
2267 }
2268 
2269 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2270 
2271 #else
2272 
2273 static inline unsigned int task_cpu(const struct task_struct *p)
2274 {
2275 	return 0;
2276 }
2277 
2278 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2279 {
2280 }
2281 
2282 #endif /* CONFIG_SMP */
2283 
2284 extern bool sched_task_on_rq(struct task_struct *p);
2285 extern unsigned long get_wchan(struct task_struct *p);
2286 extern struct task_struct *cpu_curr_snapshot(int cpu);
2287 
2288 /*
2289  * In order to reduce various lock holder preemption latencies provide an
2290  * interface to see if a vCPU is currently running or not.
2291  *
2292  * This allows us to terminate optimistic spin loops and block, analogous to
2293  * the native optimistic spin heuristic of testing if the lock owner task is
2294  * running or not.
2295  */
2296 #ifndef vcpu_is_preempted
2297 static inline bool vcpu_is_preempted(int cpu)
2298 {
2299 	return false;
2300 }
2301 #endif
2302 
2303 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2304 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2305 
2306 #ifndef TASK_SIZE_OF
2307 #define TASK_SIZE_OF(tsk)	TASK_SIZE
2308 #endif
2309 
2310 #ifdef CONFIG_SMP
2311 static inline bool owner_on_cpu(struct task_struct *owner)
2312 {
2313 	/*
2314 	 * As lock holder preemption issue, we both skip spinning if
2315 	 * task is not on cpu or its cpu is preempted
2316 	 */
2317 	return READ_ONCE(owner->on_cpu) && !vcpu_is_preempted(task_cpu(owner));
2318 }
2319 
2320 /* Returns effective CPU energy utilization, as seen by the scheduler */
2321 unsigned long sched_cpu_util(int cpu);
2322 #endif /* CONFIG_SMP */
2323 
2324 #ifdef CONFIG_RSEQ
2325 
2326 /*
2327  * Map the event mask on the user-space ABI enum rseq_cs_flags
2328  * for direct mask checks.
2329  */
2330 enum rseq_event_mask_bits {
2331 	RSEQ_EVENT_PREEMPT_BIT	= RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT,
2332 	RSEQ_EVENT_SIGNAL_BIT	= RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT,
2333 	RSEQ_EVENT_MIGRATE_BIT	= RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT,
2334 };
2335 
2336 enum rseq_event_mask {
2337 	RSEQ_EVENT_PREEMPT	= (1U << RSEQ_EVENT_PREEMPT_BIT),
2338 	RSEQ_EVENT_SIGNAL	= (1U << RSEQ_EVENT_SIGNAL_BIT),
2339 	RSEQ_EVENT_MIGRATE	= (1U << RSEQ_EVENT_MIGRATE_BIT),
2340 };
2341 
2342 static inline void rseq_set_notify_resume(struct task_struct *t)
2343 {
2344 	if (t->rseq)
2345 		set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
2346 }
2347 
2348 void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs);
2349 
2350 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
2351 					     struct pt_regs *regs)
2352 {
2353 	if (current->rseq)
2354 		__rseq_handle_notify_resume(ksig, regs);
2355 }
2356 
2357 static inline void rseq_signal_deliver(struct ksignal *ksig,
2358 				       struct pt_regs *regs)
2359 {
2360 	preempt_disable();
2361 	__set_bit(RSEQ_EVENT_SIGNAL_BIT, &current->rseq_event_mask);
2362 	preempt_enable();
2363 	rseq_handle_notify_resume(ksig, regs);
2364 }
2365 
2366 /* rseq_preempt() requires preemption to be disabled. */
2367 static inline void rseq_preempt(struct task_struct *t)
2368 {
2369 	__set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask);
2370 	rseq_set_notify_resume(t);
2371 }
2372 
2373 /* rseq_migrate() requires preemption to be disabled. */
2374 static inline void rseq_migrate(struct task_struct *t)
2375 {
2376 	__set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask);
2377 	rseq_set_notify_resume(t);
2378 }
2379 
2380 /*
2381  * If parent process has a registered restartable sequences area, the
2382  * child inherits. Unregister rseq for a clone with CLONE_VM set.
2383  */
2384 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
2385 {
2386 	if (clone_flags & CLONE_VM) {
2387 		t->rseq = NULL;
2388 		t->rseq_len = 0;
2389 		t->rseq_sig = 0;
2390 		t->rseq_event_mask = 0;
2391 	} else {
2392 		t->rseq = current->rseq;
2393 		t->rseq_len = current->rseq_len;
2394 		t->rseq_sig = current->rseq_sig;
2395 		t->rseq_event_mask = current->rseq_event_mask;
2396 	}
2397 }
2398 
2399 static inline void rseq_execve(struct task_struct *t)
2400 {
2401 	t->rseq = NULL;
2402 	t->rseq_len = 0;
2403 	t->rseq_sig = 0;
2404 	t->rseq_event_mask = 0;
2405 }
2406 
2407 #else
2408 
2409 static inline void rseq_set_notify_resume(struct task_struct *t)
2410 {
2411 }
2412 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
2413 					     struct pt_regs *regs)
2414 {
2415 }
2416 static inline void rseq_signal_deliver(struct ksignal *ksig,
2417 				       struct pt_regs *regs)
2418 {
2419 }
2420 static inline void rseq_preempt(struct task_struct *t)
2421 {
2422 }
2423 static inline void rseq_migrate(struct task_struct *t)
2424 {
2425 }
2426 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
2427 {
2428 }
2429 static inline void rseq_execve(struct task_struct *t)
2430 {
2431 }
2432 
2433 #endif
2434 
2435 #ifdef CONFIG_DEBUG_RSEQ
2436 
2437 void rseq_syscall(struct pt_regs *regs);
2438 
2439 #else
2440 
2441 static inline void rseq_syscall(struct pt_regs *regs)
2442 {
2443 }
2444 
2445 #endif
2446 
2447 #ifdef CONFIG_SCHED_CORE
2448 extern void sched_core_free(struct task_struct *tsk);
2449 extern void sched_core_fork(struct task_struct *p);
2450 extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type,
2451 				unsigned long uaddr);
2452 extern int sched_core_idle_cpu(int cpu);
2453 #else
2454 static inline void sched_core_free(struct task_struct *tsk) { }
2455 static inline void sched_core_fork(struct task_struct *p) { }
2456 static inline int sched_core_idle_cpu(int cpu) { return idle_cpu(cpu); }
2457 #endif
2458 
2459 extern void sched_set_stop_task(int cpu, struct task_struct *stop);
2460 
2461 #endif
2462