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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/mutex.h>
18 #include <linux/plist.h>
19 #include <linux/hrtimer.h>
20 #include <linux/irqflags.h>
21 #include <linux/seccomp.h>
22 #include <linux/nodemask.h>
23 #include <linux/rcupdate.h>
24 #include <linux/refcount.h>
25 #include <linux/resource.h>
26 #include <linux/latencytop.h>
27 #include <linux/sched/prio.h>
28 #include <linux/sched/types.h>
29 #include <linux/signal_types.h>
30 #include <linux/syscall_user_dispatch.h>
31 #include <linux/mm_types_task.h>
32 #include <linux/task_io_accounting.h>
33 #include <linux/posix-timers.h>
34 #include <linux/rseq.h>
35 #include <linux/seqlock.h>
36 #include <linux/kcsan.h>
37 #include <linux/android_vendor.h>
38 #include <asm/kmap_size.h>
39 #include <linux/android_kabi.h>
40 
41 /* task_struct member predeclarations (sorted alphabetically): */
42 struct audit_context;
43 struct backing_dev_info;
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_param;
67 struct seq_file;
68 struct sighand_struct;
69 struct signal_struct;
70 struct task_delay_info;
71 struct task_group;
72 
73 /*
74  * Task state bitmask. NOTE! These bits are also
75  * encoded in fs/proc/array.c: get_task_state().
76  *
77  * We have two separate sets of flags: task->state
78  * is about runnability, while task->exit_state are
79  * about the task exiting. Confusing, but this way
80  * modifying one set can't modify the other one by
81  * mistake.
82  */
83 
84 /* Used in tsk->state: */
85 #define TASK_RUNNING			0x0000
86 #define TASK_INTERRUPTIBLE		0x0001
87 #define TASK_UNINTERRUPTIBLE		0x0002
88 #define __TASK_STOPPED			0x0004
89 #define __TASK_TRACED			0x0008
90 /* Used in tsk->exit_state: */
91 #define EXIT_DEAD			0x0010
92 #define EXIT_ZOMBIE			0x0020
93 #define EXIT_TRACE			(EXIT_ZOMBIE | EXIT_DEAD)
94 /* Used in tsk->state again: */
95 #define TASK_PARKED			0x0040
96 #define TASK_DEAD			0x0080
97 #define TASK_WAKEKILL			0x0100
98 #define TASK_WAKING			0x0200
99 #define TASK_NOLOAD			0x0400
100 #define TASK_NEW			0x0800
101 /* RT specific auxilliary flag to mark RT lock waiters */
102 #define TASK_RTLOCK_WAIT		0x1000
103 #define TASK_STATE_MAX			0x2000
104 
105 /* Convenience macros for the sake of set_current_state: */
106 #define TASK_KILLABLE			(TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
107 #define TASK_STOPPED			(TASK_WAKEKILL | __TASK_STOPPED)
108 #define TASK_TRACED			(TASK_WAKEKILL | __TASK_TRACED)
109 
110 #define TASK_IDLE			(TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
111 
112 /* Convenience macros for the sake of wake_up(): */
113 #define TASK_NORMAL			(TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
114 
115 /* get_task_state(): */
116 #define TASK_REPORT			(TASK_RUNNING | TASK_INTERRUPTIBLE | \
117 					 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
118 					 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
119 					 TASK_PARKED)
120 
121 #define task_is_running(task)		(READ_ONCE((task)->__state) == TASK_RUNNING)
122 
123 #define task_is_traced(task)		((READ_ONCE(task->__state) & __TASK_TRACED) != 0)
124 
125 #define task_is_stopped(task)		((READ_ONCE(task->__state) & __TASK_STOPPED) != 0)
126 
127 #define task_is_stopped_or_traced(task)	((READ_ONCE(task->__state) & (__TASK_STOPPED | __TASK_TRACED)) != 0)
128 
129 /*
130  * Special states are those that do not use the normal wait-loop pattern. See
131  * the comment with set_special_state().
132  */
133 #define is_special_task_state(state)				\
134 	((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD))
135 
136 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
137 # define debug_normal_state_change(state_value)				\
138 	do {								\
139 		WARN_ON_ONCE(is_special_task_state(state_value));	\
140 		current->task_state_change = _THIS_IP_;			\
141 	} while (0)
142 
143 # define debug_special_state_change(state_value)			\
144 	do {								\
145 		WARN_ON_ONCE(!is_special_task_state(state_value));	\
146 		current->task_state_change = _THIS_IP_;			\
147 	} while (0)
148 
149 # define debug_rtlock_wait_set_state()					\
150 	do {								 \
151 		current->saved_state_change = current->task_state_change;\
152 		current->task_state_change = _THIS_IP_;			 \
153 	} while (0)
154 
155 # define debug_rtlock_wait_restore_state()				\
156 	do {								 \
157 		current->task_state_change = current->saved_state_change;\
158 	} while (0)
159 
160 #else
161 # define debug_normal_state_change(cond)	do { } while (0)
162 # define debug_special_state_change(cond)	do { } while (0)
163 # define debug_rtlock_wait_set_state()		do { } while (0)
164 # define debug_rtlock_wait_restore_state()	do { } while (0)
165 #endif
166 
167 /*
168  * set_current_state() includes a barrier so that the write of current->state
169  * is correctly serialised wrt the caller's subsequent test of whether to
170  * actually sleep:
171  *
172  *   for (;;) {
173  *	set_current_state(TASK_UNINTERRUPTIBLE);
174  *	if (CONDITION)
175  *	   break;
176  *
177  *	schedule();
178  *   }
179  *   __set_current_state(TASK_RUNNING);
180  *
181  * If the caller does not need such serialisation (because, for instance, the
182  * CONDITION test and condition change and wakeup are under the same lock) then
183  * use __set_current_state().
184  *
185  * The above is typically ordered against the wakeup, which does:
186  *
187  *   CONDITION = 1;
188  *   wake_up_state(p, TASK_UNINTERRUPTIBLE);
189  *
190  * where wake_up_state()/try_to_wake_up() executes a full memory barrier before
191  * accessing p->state.
192  *
193  * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is,
194  * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
195  * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
196  *
197  * However, with slightly different timing the wakeup TASK_RUNNING store can
198  * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not
199  * a problem either because that will result in one extra go around the loop
200  * and our @cond test will save the day.
201  *
202  * Also see the comments of try_to_wake_up().
203  */
204 #define __set_current_state(state_value)				\
205 	do {								\
206 		debug_normal_state_change((state_value));		\
207 		WRITE_ONCE(current->__state, (state_value));		\
208 	} while (0)
209 
210 #define set_current_state(state_value)					\
211 	do {								\
212 		debug_normal_state_change((state_value));		\
213 		smp_store_mb(current->__state, (state_value));		\
214 	} while (0)
215 
216 /*
217  * set_special_state() should be used for those states when the blocking task
218  * can not use the regular condition based wait-loop. In that case we must
219  * serialize against wakeups such that any possible in-flight TASK_RUNNING
220  * stores will not collide with our state change.
221  */
222 #define set_special_state(state_value)					\
223 	do {								\
224 		unsigned long flags; /* may shadow */			\
225 									\
226 		raw_spin_lock_irqsave(&current->pi_lock, flags);	\
227 		debug_special_state_change((state_value));		\
228 		WRITE_ONCE(current->__state, (state_value));		\
229 		raw_spin_unlock_irqrestore(&current->pi_lock, flags);	\
230 	} while (0)
231 
232 /*
233  * PREEMPT_RT specific variants for "sleeping" spin/rwlocks
234  *
235  * RT's spin/rwlock substitutions are state preserving. The state of the
236  * task when blocking on the lock is saved in task_struct::saved_state and
237  * restored after the lock has been acquired.  These operations are
238  * serialized by task_struct::pi_lock against try_to_wake_up(). Any non RT
239  * lock related wakeups while the task is blocked on the lock are
240  * redirected to operate on task_struct::saved_state to ensure that these
241  * are not dropped. On restore task_struct::saved_state is set to
242  * TASK_RUNNING so any wakeup attempt redirected to saved_state will fail.
243  *
244  * The lock operation looks like this:
245  *
246  *	current_save_and_set_rtlock_wait_state();
247  *	for (;;) {
248  *		if (try_lock())
249  *			break;
250  *		raw_spin_unlock_irq(&lock->wait_lock);
251  *		schedule_rtlock();
252  *		raw_spin_lock_irq(&lock->wait_lock);
253  *		set_current_state(TASK_RTLOCK_WAIT);
254  *	}
255  *	current_restore_rtlock_saved_state();
256  */
257 #define current_save_and_set_rtlock_wait_state()			\
258 	do {								\
259 		lockdep_assert_irqs_disabled();				\
260 		raw_spin_lock(&current->pi_lock);			\
261 		current->saved_state = current->__state;		\
262 		debug_rtlock_wait_set_state();				\
263 		WRITE_ONCE(current->__state, TASK_RTLOCK_WAIT);		\
264 		raw_spin_unlock(&current->pi_lock);			\
265 	} while (0);
266 
267 #define current_restore_rtlock_saved_state()				\
268 	do {								\
269 		lockdep_assert_irqs_disabled();				\
270 		raw_spin_lock(&current->pi_lock);			\
271 		debug_rtlock_wait_restore_state();			\
272 		WRITE_ONCE(current->__state, current->saved_state);	\
273 		current->saved_state = TASK_RUNNING;			\
274 		raw_spin_unlock(&current->pi_lock);			\
275 	} while (0);
276 
277 #define get_current_state()	READ_ONCE(current->__state)
278 
279 /* Task command name length: */
280 #define TASK_COMM_LEN			16
281 
282 extern void scheduler_tick(void);
283 
284 #define	MAX_SCHEDULE_TIMEOUT		LONG_MAX
285 
286 extern long schedule_timeout(long timeout);
287 extern long schedule_timeout_interruptible(long timeout);
288 extern long schedule_timeout_killable(long timeout);
289 extern long schedule_timeout_uninterruptible(long timeout);
290 extern long schedule_timeout_idle(long timeout);
291 asmlinkage void schedule(void);
292 extern void schedule_preempt_disabled(void);
293 asmlinkage void preempt_schedule_irq(void);
294 #ifdef CONFIG_PREEMPT_RT
295  extern void schedule_rtlock(void);
296 #endif
297 
298 extern int __must_check io_schedule_prepare(void);
299 extern void io_schedule_finish(int token);
300 extern long io_schedule_timeout(long timeout);
301 extern void io_schedule(void);
302 extern struct task_struct *pick_migrate_task(struct rq *rq);
303 extern int select_fallback_rq(int cpu, struct task_struct *p);
304 
305 /**
306  * struct prev_cputime - snapshot of system and user cputime
307  * @utime: time spent in user mode
308  * @stime: time spent in system mode
309  * @lock: protects the above two fields
310  *
311  * Stores previous user/system time values such that we can guarantee
312  * monotonicity.
313  */
314 struct prev_cputime {
315 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
316 	u64				utime;
317 	u64				stime;
318 	raw_spinlock_t			lock;
319 #endif
320 };
321 
322 enum vtime_state {
323 	/* Task is sleeping or running in a CPU with VTIME inactive: */
324 	VTIME_INACTIVE = 0,
325 	/* Task is idle */
326 	VTIME_IDLE,
327 	/* Task runs in kernelspace in a CPU with VTIME active: */
328 	VTIME_SYS,
329 	/* Task runs in userspace in a CPU with VTIME active: */
330 	VTIME_USER,
331 	/* Task runs as guests in a CPU with VTIME active: */
332 	VTIME_GUEST,
333 };
334 
335 struct vtime {
336 	seqcount_t		seqcount;
337 	unsigned long long	starttime;
338 	enum vtime_state	state;
339 	unsigned int		cpu;
340 	u64			utime;
341 	u64			stime;
342 	u64			gtime;
343 };
344 
345 /*
346  * Utilization clamp constraints.
347  * @UCLAMP_MIN:	Minimum utilization
348  * @UCLAMP_MAX:	Maximum utilization
349  * @UCLAMP_CNT:	Utilization clamp constraints count
350  */
351 enum uclamp_id {
352 	UCLAMP_MIN = 0,
353 	UCLAMP_MAX,
354 	UCLAMP_CNT
355 };
356 
357 #ifdef CONFIG_SMP
358 extern struct root_domain def_root_domain;
359 extern struct mutex sched_domains_mutex;
360 #endif
361 
362 struct sched_info {
363 #ifdef CONFIG_SCHED_INFO
364 	/* Cumulative counters: */
365 
366 	/* # of times we have run on this CPU: */
367 	unsigned long			pcount;
368 
369 	/* Time spent waiting on a runqueue: */
370 	unsigned long long		run_delay;
371 
372 	/* Timestamps: */
373 
374 	/* When did we last run on a CPU? */
375 	unsigned long long		last_arrival;
376 
377 	/* When were we last queued to run? */
378 	unsigned long long		last_queued;
379 
380 #endif /* CONFIG_SCHED_INFO */
381 };
382 
383 /*
384  * Integer metrics need fixed point arithmetic, e.g., sched/fair
385  * has a few: load, load_avg, util_avg, freq, and capacity.
386  *
387  * We define a basic fixed point arithmetic range, and then formalize
388  * all these metrics based on that basic range.
389  */
390 # define SCHED_FIXEDPOINT_SHIFT		10
391 # define SCHED_FIXEDPOINT_SCALE		(1L << SCHED_FIXEDPOINT_SHIFT)
392 
393 /* Increase resolution of cpu_capacity calculations */
394 # define SCHED_CAPACITY_SHIFT		SCHED_FIXEDPOINT_SHIFT
395 # define SCHED_CAPACITY_SCALE		(1L << SCHED_CAPACITY_SHIFT)
396 
397 struct load_weight {
398 	unsigned long			weight;
399 	u32				inv_weight;
400 };
401 
402 /**
403  * struct util_est - Estimation utilization of FAIR tasks
404  * @enqueued: instantaneous estimated utilization of a task/cpu
405  * @ewma:     the Exponential Weighted Moving Average (EWMA)
406  *            utilization of a task
407  *
408  * Support data structure to track an Exponential Weighted Moving Average
409  * (EWMA) of a FAIR task's utilization. New samples are added to the moving
410  * average each time a task completes an activation. Sample's weight is chosen
411  * so that the EWMA will be relatively insensitive to transient changes to the
412  * task's workload.
413  *
414  * The enqueued attribute has a slightly different meaning for tasks and cpus:
415  * - task:   the task's util_avg at last task dequeue time
416  * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU
417  * Thus, the util_est.enqueued of a task represents the contribution on the
418  * estimated utilization of the CPU where that task is currently enqueued.
419  *
420  * Only for tasks we track a moving average of the past instantaneous
421  * estimated utilization. This allows to absorb sporadic drops in utilization
422  * of an otherwise almost periodic task.
423  *
424  * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg
425  * updates. When a task is dequeued, its util_est should not be updated if its
426  * util_avg has not been updated in the meantime.
427  * This information is mapped into the MSB bit of util_est.enqueued at dequeue
428  * time. Since max value of util_est.enqueued for a task is 1024 (PELT util_avg
429  * for a task) it is safe to use MSB.
430  */
431 struct util_est {
432 	unsigned int			enqueued;
433 	unsigned int			ewma;
434 #define UTIL_EST_WEIGHT_SHIFT		2
435 #define UTIL_AVG_UNCHANGED		0x80000000
436 } __attribute__((__aligned__(sizeof(u64))));
437 
438 /*
439  * The load/runnable/util_avg accumulates an infinite geometric series
440  * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c).
441  *
442  * [load_avg definition]
443  *
444  *   load_avg = runnable% * scale_load_down(load)
445  *
446  * [runnable_avg definition]
447  *
448  *   runnable_avg = runnable% * SCHED_CAPACITY_SCALE
449  *
450  * [util_avg definition]
451  *
452  *   util_avg = running% * SCHED_CAPACITY_SCALE
453  *
454  * where runnable% is the time ratio that a sched_entity is runnable and
455  * running% the time ratio that a sched_entity is running.
456  *
457  * For cfs_rq, they are the aggregated values of all runnable and blocked
458  * sched_entities.
459  *
460  * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU
461  * capacity scaling. The scaling is done through the rq_clock_pelt that is used
462  * for computing those signals (see update_rq_clock_pelt())
463  *
464  * N.B., the above ratios (runnable% and running%) themselves are in the
465  * range of [0, 1]. To do fixed point arithmetics, we therefore scale them
466  * to as large a range as necessary. This is for example reflected by
467  * util_avg's SCHED_CAPACITY_SCALE.
468  *
469  * [Overflow issue]
470  *
471  * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
472  * with the highest load (=88761), always runnable on a single cfs_rq,
473  * and should not overflow as the number already hits PID_MAX_LIMIT.
474  *
475  * For all other cases (including 32-bit kernels), struct load_weight's
476  * weight will overflow first before we do, because:
477  *
478  *    Max(load_avg) <= Max(load.weight)
479  *
480  * Then it is the load_weight's responsibility to consider overflow
481  * issues.
482  */
483 struct sched_avg {
484 	u64				last_update_time;
485 	u64				load_sum;
486 	u64				runnable_sum;
487 	u32				util_sum;
488 	u32				period_contrib;
489 	unsigned long			load_avg;
490 	unsigned long			runnable_avg;
491 	unsigned long			util_avg;
492 	struct util_est			util_est;
493 } ____cacheline_aligned;
494 
495 struct sched_statistics {
496 #ifdef CONFIG_SCHEDSTATS
497 	u64				wait_start;
498 	u64				wait_max;
499 	u64				wait_count;
500 	u64				wait_sum;
501 	u64				iowait_count;
502 	u64				iowait_sum;
503 
504 	u64				sleep_start;
505 	u64				sleep_max;
506 	s64				sum_sleep_runtime;
507 
508 	u64				block_start;
509 	u64				block_max;
510 	u64				exec_max;
511 	u64				slice_max;
512 
513 	u64				nr_migrations_cold;
514 	u64				nr_failed_migrations_affine;
515 	u64				nr_failed_migrations_running;
516 	u64				nr_failed_migrations_hot;
517 	u64				nr_forced_migrations;
518 
519 	u64				nr_wakeups;
520 	u64				nr_wakeups_sync;
521 	u64				nr_wakeups_migrate;
522 	u64				nr_wakeups_local;
523 	u64				nr_wakeups_remote;
524 	u64				nr_wakeups_affine;
525 	u64				nr_wakeups_affine_attempts;
526 	u64				nr_wakeups_passive;
527 	u64				nr_wakeups_idle;
528 #endif
529 } ____cacheline_aligned;
530 
531 struct sched_entity {
532 	/* For load-balancing: */
533 	struct load_weight		load;
534 	struct rb_node			run_node;
535 	struct list_head		group_node;
536 	unsigned int			on_rq;
537 
538 	u64				exec_start;
539 	u64				sum_exec_runtime;
540 	u64				vruntime;
541 	u64				prev_sum_exec_runtime;
542 
543 	u64				nr_migrations;
544 
545 #ifdef CONFIG_FAIR_GROUP_SCHED
546 	int				depth;
547 	struct sched_entity		*parent;
548 	/* rq on which this entity is (to be) queued: */
549 	struct cfs_rq			*cfs_rq;
550 	/* rq "owned" by this entity/group: */
551 	struct cfs_rq			*my_q;
552 	/* cached value of my_q->h_nr_running */
553 	unsigned long			runnable_weight;
554 #endif
555 
556 #ifdef CONFIG_SMP
557 	/*
558 	 * Per entity load average tracking.
559 	 *
560 	 * Put into separate cache line so it does not
561 	 * collide with read-mostly values above.
562 	 */
563 	struct sched_avg		avg;
564 #endif
565 
566 	ANDROID_KABI_RESERVE(1);
567 	ANDROID_KABI_RESERVE(2);
568 	ANDROID_KABI_RESERVE(3);
569 	ANDROID_KABI_RESERVE(4);
570 };
571 
572 struct sched_rt_entity {
573 	struct list_head		run_list;
574 	unsigned long			timeout;
575 	unsigned long			watchdog_stamp;
576 	unsigned int			time_slice;
577 	unsigned short			on_rq;
578 	unsigned short			on_list;
579 
580 	struct sched_rt_entity		*back;
581 #ifdef CONFIG_RT_GROUP_SCHED
582 	struct sched_rt_entity		*parent;
583 	/* rq on which this entity is (to be) queued: */
584 	struct rt_rq			*rt_rq;
585 	/* rq "owned" by this entity/group: */
586 	struct rt_rq			*my_q;
587 #endif
588 
589 	ANDROID_KABI_RESERVE(1);
590 	ANDROID_KABI_RESERVE(2);
591 	ANDROID_KABI_RESERVE(3);
592 	ANDROID_KABI_RESERVE(4);
593 } __randomize_layout;
594 
595 struct sched_dl_entity {
596 	struct rb_node			rb_node;
597 
598 	/*
599 	 * Original scheduling parameters. Copied here from sched_attr
600 	 * during sched_setattr(), they will remain the same until
601 	 * the next sched_setattr().
602 	 */
603 	u64				dl_runtime;	/* Maximum runtime for each instance	*/
604 	u64				dl_deadline;	/* Relative deadline of each instance	*/
605 	u64				dl_period;	/* Separation of two instances (period) */
606 	u64				dl_bw;		/* dl_runtime / dl_period		*/
607 	u64				dl_density;	/* dl_runtime / dl_deadline		*/
608 
609 	/*
610 	 * Actual scheduling parameters. Initialized with the values above,
611 	 * they are continuously updated during task execution. Note that
612 	 * the remaining runtime could be < 0 in case we are in overrun.
613 	 */
614 	s64				runtime;	/* Remaining runtime for this instance	*/
615 	u64				deadline;	/* Absolute deadline for this instance	*/
616 	unsigned int			flags;		/* Specifying the scheduler behaviour	*/
617 
618 	/*
619 	 * Some bool flags:
620 	 *
621 	 * @dl_throttled tells if we exhausted the runtime. If so, the
622 	 * task has to wait for a replenishment to be performed at the
623 	 * next firing of dl_timer.
624 	 *
625 	 * @dl_yielded tells if task gave up the CPU before consuming
626 	 * all its available runtime during the last job.
627 	 *
628 	 * @dl_non_contending tells if the task is inactive while still
629 	 * contributing to the active utilization. In other words, it
630 	 * indicates if the inactive timer has been armed and its handler
631 	 * has not been executed yet. This flag is useful to avoid race
632 	 * conditions between the inactive timer handler and the wakeup
633 	 * code.
634 	 *
635 	 * @dl_overrun tells if the task asked to be informed about runtime
636 	 * overruns.
637 	 */
638 	unsigned int			dl_throttled      : 1;
639 	unsigned int			dl_yielded        : 1;
640 	unsigned int			dl_non_contending : 1;
641 	unsigned int			dl_overrun	  : 1;
642 
643 	/*
644 	 * Bandwidth enforcement timer. Each -deadline task has its
645 	 * own bandwidth to be enforced, thus we need one timer per task.
646 	 */
647 	struct hrtimer			dl_timer;
648 
649 	/*
650 	 * Inactive timer, responsible for decreasing the active utilization
651 	 * at the "0-lag time". When a -deadline task blocks, it contributes
652 	 * to GRUB's active utilization until the "0-lag time", hence a
653 	 * timer is needed to decrease the active utilization at the correct
654 	 * time.
655 	 */
656 	struct hrtimer inactive_timer;
657 
658 #ifdef CONFIG_RT_MUTEXES
659 	/*
660 	 * Priority Inheritance. When a DEADLINE scheduling entity is boosted
661 	 * pi_se points to the donor, otherwise points to the dl_se it belongs
662 	 * to (the original one/itself).
663 	 */
664 	struct sched_dl_entity *pi_se;
665 #endif
666 };
667 
668 #ifdef CONFIG_UCLAMP_TASK
669 /* Number of utilization clamp buckets (shorter alias) */
670 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT
671 
672 /*
673  * Utilization clamp for a scheduling entity
674  * @value:		clamp value "assigned" to a se
675  * @bucket_id:		bucket index corresponding to the "assigned" value
676  * @active:		the se is currently refcounted in a rq's bucket
677  * @user_defined:	the requested clamp value comes from user-space
678  *
679  * The bucket_id is the index of the clamp bucket matching the clamp value
680  * which is pre-computed and stored to avoid expensive integer divisions from
681  * the fast path.
682  *
683  * The active bit is set whenever a task has got an "effective" value assigned,
684  * which can be different from the clamp value "requested" from user-space.
685  * This allows to know a task is refcounted in the rq's bucket corresponding
686  * to the "effective" bucket_id.
687  *
688  * The user_defined bit is set whenever a task has got a task-specific clamp
689  * value requested from userspace, i.e. the system defaults apply to this task
690  * just as a restriction. This allows to relax default clamps when a less
691  * restrictive task-specific value has been requested, thus allowing to
692  * implement a "nice" semantic. For example, a task running with a 20%
693  * default boost can still drop its own boosting to 0%.
694  */
695 struct uclamp_se {
696 	unsigned int value		: bits_per(SCHED_CAPACITY_SCALE);
697 	unsigned int bucket_id		: bits_per(UCLAMP_BUCKETS);
698 	unsigned int active		: 1;
699 	unsigned int user_defined	: 1;
700 };
701 #endif /* CONFIG_UCLAMP_TASK */
702 
703 union rcu_special {
704 	struct {
705 		u8			blocked;
706 		u8			need_qs;
707 		u8			exp_hint; /* Hint for performance. */
708 		u8			need_mb; /* Readers need smp_mb(). */
709 	} b; /* Bits. */
710 	u32 s; /* Set of bits. */
711 };
712 
713 enum perf_event_task_context {
714 	perf_invalid_context = -1,
715 	perf_hw_context = 0,
716 	perf_sw_context,
717 	perf_nr_task_contexts,
718 };
719 
720 struct wake_q_node {
721 	struct wake_q_node *next;
722 };
723 
724 struct kmap_ctrl {
725 #ifdef CONFIG_KMAP_LOCAL
726 	int				idx;
727 	pte_t				pteval[KM_MAX_IDX];
728 #endif
729 };
730 
731 struct task_struct {
732 #ifdef CONFIG_THREAD_INFO_IN_TASK
733 	/*
734 	 * For reasons of header soup (see current_thread_info()), this
735 	 * must be the first element of task_struct.
736 	 */
737 	struct thread_info		thread_info;
738 #endif
739 	unsigned int			__state;
740 
741 #ifdef CONFIG_PREEMPT_RT
742 	/* saved state for "spinlock sleepers" */
743 	unsigned int			saved_state;
744 #endif
745 
746 	/*
747 	 * This begins the randomizable portion of task_struct. Only
748 	 * scheduling-critical items should be added above here.
749 	 */
750 	randomized_struct_fields_start
751 
752 	void				*stack;
753 	refcount_t			usage;
754 	/* Per task flags (PF_*), defined further below: */
755 	unsigned int			flags;
756 	unsigned int			ptrace;
757 
758 #ifdef CONFIG_SMP
759 	int				on_cpu;
760 	struct __call_single_node	wake_entry;
761 #ifdef CONFIG_THREAD_INFO_IN_TASK
762 	/* Current CPU: */
763 	unsigned int			cpu;
764 #endif
765 	unsigned int			wakee_flips;
766 	unsigned long			wakee_flip_decay_ts;
767 	struct task_struct		*last_wakee;
768 
769 	/*
770 	 * recent_used_cpu is initially set as the last CPU used by a task
771 	 * that wakes affine another task. Waker/wakee relationships can
772 	 * push tasks around a CPU where each wakeup moves to the next one.
773 	 * Tracking a recently used CPU allows a quick search for a recently
774 	 * used CPU that may be idle.
775 	 */
776 	int				recent_used_cpu;
777 	int				wake_cpu;
778 #endif
779 	int				on_rq;
780 
781 	int				prio;
782 	int				static_prio;
783 	int				normal_prio;
784 	unsigned int			rt_priority;
785 
786 	const struct sched_class	*sched_class;
787 	struct sched_entity		se;
788 	struct sched_rt_entity		rt;
789 	struct sched_dl_entity		dl;
790 
791 #ifdef CONFIG_SCHED_CORE
792 	struct rb_node			core_node;
793 	unsigned long			core_cookie;
794 	unsigned int			core_occupation;
795 #endif
796 
797 #ifdef CONFIG_CGROUP_SCHED
798 	struct task_group		*sched_task_group;
799 #endif
800 
801 #ifdef CONFIG_UCLAMP_TASK
802 	/*
803 	 * Clamp values requested for a scheduling entity.
804 	 * Must be updated with task_rq_lock() held.
805 	 */
806 	struct uclamp_se		uclamp_req[UCLAMP_CNT];
807 	/*
808 	 * Effective clamp values used for a scheduling entity.
809 	 * Must be updated with task_rq_lock() held.
810 	 */
811 	struct uclamp_se		uclamp[UCLAMP_CNT];
812 #endif
813 
814 	struct sched_statistics         stats;
815 
816 #ifdef CONFIG_PREEMPT_NOTIFIERS
817 	/* List of struct preempt_notifier: */
818 	struct hlist_head		preempt_notifiers;
819 #endif
820 
821 #ifdef CONFIG_BLK_DEV_IO_TRACE
822 	unsigned int			btrace_seq;
823 #endif
824 
825 	unsigned int			policy;
826 	int				nr_cpus_allowed;
827 	const cpumask_t			*cpus_ptr;
828 	cpumask_t			*user_cpus_ptr;
829 	cpumask_t			cpus_mask;
830 	void				*migration_pending;
831 #ifdef CONFIG_SMP
832 	unsigned short			migration_disabled;
833 #endif
834 	unsigned short			migration_flags;
835 
836 #ifdef CONFIG_PREEMPT_RCU
837 	int				rcu_read_lock_nesting;
838 	union rcu_special		rcu_read_unlock_special;
839 	struct list_head		rcu_node_entry;
840 	struct rcu_node			*rcu_blocked_node;
841 #endif /* #ifdef CONFIG_PREEMPT_RCU */
842 
843 #ifdef CONFIG_TASKS_RCU
844 	unsigned long			rcu_tasks_nvcsw;
845 	u8				rcu_tasks_holdout;
846 	u8				rcu_tasks_idx;
847 	int				rcu_tasks_idle_cpu;
848 	struct list_head		rcu_tasks_holdout_list;
849 #endif /* #ifdef CONFIG_TASKS_RCU */
850 
851 #ifdef CONFIG_TASKS_TRACE_RCU
852 	int				trc_reader_nesting;
853 	int				trc_ipi_to_cpu;
854 	union rcu_special		trc_reader_special;
855 	bool				trc_reader_checked;
856 	struct list_head		trc_holdout_list;
857 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
858 
859 	struct sched_info		sched_info;
860 
861 	struct list_head		tasks;
862 #ifdef CONFIG_SMP
863 	struct plist_node		pushable_tasks;
864 	struct rb_node			pushable_dl_tasks;
865 #endif
866 
867 	struct mm_struct		*mm;
868 	struct mm_struct		*active_mm;
869 
870 	/* Per-thread vma caching: */
871 	struct vmacache			vmacache;
872 
873 #ifdef SPLIT_RSS_COUNTING
874 	struct task_rss_stat		rss_stat;
875 #endif
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 #ifdef CONFIG_PSI
892 	unsigned			sched_psi_wake_requeue:1;
893 #endif
894 
895 	/* Force alignment to the next boundary: */
896 	unsigned			:0;
897 
898 	/* Unserialized, strictly 'current' */
899 
900 	/*
901 	 * This field must not be in the scheduler word above due to wakelist
902 	 * queueing no longer being serialized by p->on_cpu. However:
903 	 *
904 	 * p->XXX = X;			ttwu()
905 	 * schedule()			  if (p->on_rq && ..) // false
906 	 *   smp_mb__after_spinlock();	  if (smp_load_acquire(&p->on_cpu) && //true
907 	 *   deactivate_task()		      ttwu_queue_wakelist())
908 	 *     p->on_rq = 0;			p->sched_remote_wakeup = Y;
909 	 *
910 	 * guarantees all stores of 'current' are visible before
911 	 * ->sched_remote_wakeup gets used, so it can be in this word.
912 	 */
913 	unsigned			sched_remote_wakeup:1;
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 
953 	unsigned long			atomic_flags; /* Flags requiring atomic access. */
954 
955 	struct restart_block		restart_block;
956 
957 	pid_t				pid;
958 	pid_t				tgid;
959 
960 #ifdef CONFIG_STACKPROTECTOR
961 	/* Canary value for the -fstack-protector GCC feature: */
962 	unsigned long			stack_canary;
963 #endif
964 	/*
965 	 * Pointers to the (original) parent process, youngest child, younger sibling,
966 	 * older sibling, respectively.  (p->father can be replaced with
967 	 * p->real_parent->pid)
968 	 */
969 
970 	/* Real parent process: */
971 	struct task_struct __rcu	*real_parent;
972 
973 	/* Recipient of SIGCHLD, wait4() reports: */
974 	struct task_struct __rcu	*parent;
975 
976 	/*
977 	 * Children/sibling form the list of natural children:
978 	 */
979 	struct list_head		children;
980 	struct list_head		sibling;
981 	struct task_struct		*group_leader;
982 
983 	/*
984 	 * 'ptraced' is the list of tasks this task is using ptrace() on.
985 	 *
986 	 * This includes both natural children and PTRACE_ATTACH targets.
987 	 * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
988 	 */
989 	struct list_head		ptraced;
990 	struct list_head		ptrace_entry;
991 
992 	/* PID/PID hash table linkage. */
993 	struct pid			*thread_pid;
994 	struct hlist_node		pid_links[PIDTYPE_MAX];
995 	struct list_head		thread_group;
996 	struct list_head		thread_node;
997 
998 	struct completion		*vfork_done;
999 
1000 	/* CLONE_CHILD_SETTID: */
1001 	int __user			*set_child_tid;
1002 
1003 	/* CLONE_CHILD_CLEARTID: */
1004 	int __user			*clear_child_tid;
1005 
1006 	/* PF_IO_WORKER */
1007 	void				*pf_io_worker;
1008 
1009 	u64				utime;
1010 	u64				stime;
1011 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
1012 	u64				utimescaled;
1013 	u64				stimescaled;
1014 #endif
1015 	u64				gtime;
1016 #ifdef CONFIG_CPU_FREQ_TIMES
1017 	u64				*time_in_state;
1018 	unsigned int			max_state;
1019 #endif
1020 	struct prev_cputime		prev_cputime;
1021 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1022 	struct vtime			vtime;
1023 #endif
1024 
1025 #ifdef CONFIG_NO_HZ_FULL
1026 	atomic_t			tick_dep_mask;
1027 #endif
1028 	/* Context switch counts: */
1029 	unsigned long			nvcsw;
1030 	unsigned long			nivcsw;
1031 
1032 	/* Monotonic time in nsecs: */
1033 	u64				start_time;
1034 
1035 	/* Boot based time in nsecs: */
1036 	u64				start_boottime;
1037 
1038 	/* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
1039 	unsigned long			min_flt;
1040 	unsigned long			maj_flt;
1041 
1042 	/* Empty if CONFIG_POSIX_CPUTIMERS=n */
1043 	struct posix_cputimers		posix_cputimers;
1044 
1045 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK
1046 	struct posix_cputimers_work	posix_cputimers_work;
1047 #endif
1048 
1049 	/* Process credentials: */
1050 
1051 	/* Tracer's credentials at attach: */
1052 	const struct cred __rcu		*ptracer_cred;
1053 
1054 	/* Objective and real subjective task credentials (COW): */
1055 	const struct cred __rcu		*real_cred;
1056 
1057 	/* Effective (overridable) subjective task credentials (COW): */
1058 	const struct cred __rcu		*cred;
1059 
1060 #ifdef CONFIG_KEYS
1061 	/* Cached requested key. */
1062 	struct key			*cached_requested_key;
1063 #endif
1064 
1065 	/*
1066 	 * executable name, excluding path.
1067 	 *
1068 	 * - normally initialized setup_new_exec()
1069 	 * - access it with [gs]et_task_comm()
1070 	 * - lock it with task_lock()
1071 	 */
1072 	char				comm[TASK_COMM_LEN];
1073 
1074 	struct nameidata		*nameidata;
1075 
1076 #ifdef CONFIG_SYSVIPC
1077 	struct sysv_sem			sysvsem;
1078 	struct sysv_shm			sysvshm;
1079 #endif
1080 #ifdef CONFIG_DETECT_HUNG_TASK
1081 	unsigned long			last_switch_count;
1082 	unsigned long			last_switch_time;
1083 #endif
1084 	/* Filesystem information: */
1085 	struct fs_struct		*fs;
1086 
1087 	/* Open file information: */
1088 	struct files_struct		*files;
1089 
1090 #ifdef CONFIG_IO_URING
1091 	struct io_uring_task		*io_uring;
1092 #endif
1093 
1094 	/* Namespaces: */
1095 	struct nsproxy			*nsproxy;
1096 
1097 	/* Signal handlers: */
1098 	struct signal_struct		*signal;
1099 	struct sighand_struct __rcu		*sighand;
1100 	sigset_t			blocked;
1101 	sigset_t			real_blocked;
1102 	/* Restored if set_restore_sigmask() was used: */
1103 	sigset_t			saved_sigmask;
1104 	struct sigpending		pending;
1105 	unsigned long			sas_ss_sp;
1106 	size_t				sas_ss_size;
1107 	unsigned int			sas_ss_flags;
1108 
1109 	struct callback_head		*task_works;
1110 
1111 #ifdef CONFIG_AUDIT
1112 #ifdef CONFIG_AUDITSYSCALL
1113 	struct audit_context		*audit_context;
1114 #endif
1115 	kuid_t				loginuid;
1116 	unsigned int			sessionid;
1117 #endif
1118 	struct seccomp			seccomp;
1119 	struct syscall_user_dispatch	syscall_dispatch;
1120 
1121 	/* Thread group tracking: */
1122 	u64				parent_exec_id;
1123 	u64				self_exec_id;
1124 
1125 	/* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
1126 	spinlock_t			alloc_lock;
1127 
1128 	/* Protection of the PI data structures: */
1129 	raw_spinlock_t			pi_lock;
1130 
1131 	struct wake_q_node		wake_q;
1132 	int				wake_q_count;
1133 
1134 #ifdef CONFIG_RT_MUTEXES
1135 	/* PI waiters blocked on a rt_mutex held by this task: */
1136 	struct rb_root_cached		pi_waiters;
1137 	/* Updated under owner's pi_lock and rq lock */
1138 	struct task_struct		*pi_top_task;
1139 	/* Deadlock detection and priority inheritance handling: */
1140 	struct rt_mutex_waiter		*pi_blocked_on;
1141 #endif
1142 
1143 #ifdef CONFIG_DEBUG_MUTEXES
1144 	/* Mutex deadlock detection: */
1145 	struct mutex_waiter		*blocked_on;
1146 #endif
1147 
1148 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1149 	int				non_block_count;
1150 #endif
1151 
1152 #ifdef CONFIG_TRACE_IRQFLAGS
1153 	struct irqtrace_events		irqtrace;
1154 	unsigned int			hardirq_threaded;
1155 	u64				hardirq_chain_key;
1156 	int				softirqs_enabled;
1157 	int				softirq_context;
1158 	int				irq_config;
1159 #endif
1160 #ifdef CONFIG_PREEMPT_RT
1161 	int				softirq_disable_cnt;
1162 #endif
1163 
1164 #ifdef CONFIG_LOCKDEP
1165 # define MAX_LOCK_DEPTH			48UL
1166 	u64				curr_chain_key;
1167 	int				lockdep_depth;
1168 	unsigned int			lockdep_recursion;
1169 	struct held_lock		held_locks[MAX_LOCK_DEPTH];
1170 #endif
1171 
1172 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP)
1173 	unsigned int			in_ubsan;
1174 #endif
1175 
1176 	/* Journalling filesystem info: */
1177 	void				*journal_info;
1178 
1179 	/* Stacked block device info: */
1180 	struct bio_list			*bio_list;
1181 
1182 #ifdef CONFIG_BLOCK
1183 	/* Stack plugging: */
1184 	struct blk_plug			*plug;
1185 #endif
1186 
1187 	/* VM state: */
1188 	struct reclaim_state		*reclaim_state;
1189 
1190 	struct backing_dev_info		*backing_dev_info;
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[perf_nr_task_contexts];
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_sig;
1309 	/*
1310 	 * RmW on rseq_event_mask must be performed atomically
1311 	 * with respect to preemption.
1312 	 */
1313 	unsigned long rseq_event_mask;
1314 #endif
1315 
1316 	struct tlbflush_unmap_batch	tlb_ubc;
1317 
1318 	union {
1319 		refcount_t		rcu_users;
1320 		struct rcu_head		rcu;
1321 	};
1322 
1323 	/* Cache last used pipe for splice(): */
1324 	struct pipe_inode_info		*splice_pipe;
1325 
1326 	struct page_frag		task_frag;
1327 
1328 #ifdef CONFIG_TASK_DELAY_ACCT
1329 	struct task_delay_info		*delays;
1330 #endif
1331 
1332 #ifdef CONFIG_FAULT_INJECTION
1333 	int				make_it_fail;
1334 	unsigned int			fail_nth;
1335 #endif
1336 	/*
1337 	 * When (nr_dirtied >= nr_dirtied_pause), it's time to call
1338 	 * balance_dirty_pages() for a dirty throttling pause:
1339 	 */
1340 	int				nr_dirtied;
1341 	int				nr_dirtied_pause;
1342 	/* Start of a write-and-pause period: */
1343 	unsigned long			dirty_paused_when;
1344 
1345 #ifdef CONFIG_LATENCYTOP
1346 	int				latency_record_count;
1347 	struct latency_record		latency_record[LT_SAVECOUNT];
1348 #endif
1349 	/*
1350 	 * Time slack values; these are used to round up poll() and
1351 	 * select() etc timeout values. These are in nanoseconds.
1352 	 */
1353 	u64				timer_slack_ns;
1354 	u64				default_timer_slack_ns;
1355 
1356 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
1357 	unsigned int			kasan_depth;
1358 #endif
1359 
1360 #ifdef CONFIG_KCSAN
1361 	struct kcsan_ctx		kcsan_ctx;
1362 #ifdef CONFIG_TRACE_IRQFLAGS
1363 	struct irqtrace_events		kcsan_save_irqtrace;
1364 #endif
1365 #endif
1366 
1367 	struct kunit			*kunit_test;
1368 
1369 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1370 	/* Index of current stored address in ret_stack: */
1371 	int				curr_ret_stack;
1372 	int				curr_ret_depth;
1373 
1374 	/* Stack of return addresses for return function tracing: */
1375 	struct ftrace_ret_stack		*ret_stack;
1376 
1377 	/* Timestamp for last schedule: */
1378 	unsigned long long		ftrace_timestamp;
1379 
1380 	/*
1381 	 * Number of functions that haven't been traced
1382 	 * because of depth overrun:
1383 	 */
1384 	atomic_t			trace_overrun;
1385 
1386 	/* Pause tracing: */
1387 	atomic_t			tracing_graph_pause;
1388 #endif
1389 
1390 #ifdef CONFIG_TRACING
1391 	/* State flags for use by tracers: */
1392 	unsigned long			trace;
1393 
1394 	/* Bitmask and counter of trace recursion: */
1395 	unsigned long			trace_recursion;
1396 #endif /* CONFIG_TRACING */
1397 
1398 #ifdef CONFIG_KCOV
1399 	/* See kernel/kcov.c for more details. */
1400 
1401 	/* Coverage collection mode enabled for this task (0 if disabled): */
1402 	unsigned int			kcov_mode;
1403 
1404 	/* Size of the kcov_area: */
1405 	unsigned int			kcov_size;
1406 
1407 	/* Buffer for coverage collection: */
1408 	void				*kcov_area;
1409 
1410 	/* KCOV descriptor wired with this task or NULL: */
1411 	struct kcov			*kcov;
1412 
1413 	/* KCOV common handle for remote coverage collection: */
1414 	u64				kcov_handle;
1415 
1416 	/* KCOV sequence number: */
1417 	int				kcov_sequence;
1418 
1419 	/* Collect coverage from softirq context: */
1420 	unsigned int			kcov_softirq;
1421 #endif
1422 
1423 #ifdef CONFIG_MEMCG
1424 	struct mem_cgroup		*memcg_in_oom;
1425 	gfp_t				memcg_oom_gfp_mask;
1426 	int				memcg_oom_order;
1427 
1428 	/* Number of pages to reclaim on returning to userland: */
1429 	unsigned int			memcg_nr_pages_over_high;
1430 
1431 	/* Used by memcontrol for targeted memcg charge: */
1432 	struct mem_cgroup		*active_memcg;
1433 #endif
1434 
1435 #ifdef CONFIG_BLK_CGROUP
1436 	struct request_queue		*throttle_queue;
1437 #endif
1438 
1439 #ifdef CONFIG_UPROBES
1440 	struct uprobe_task		*utask;
1441 #endif
1442 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1443 	unsigned int			sequential_io;
1444 	unsigned int			sequential_io_avg;
1445 #endif
1446 	struct kmap_ctrl		kmap_ctrl;
1447 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1448 	unsigned long			task_state_change;
1449 # ifdef CONFIG_PREEMPT_RT
1450 	unsigned long			saved_state_change;
1451 # endif
1452 #endif
1453 	int				pagefault_disabled;
1454 #ifdef CONFIG_MMU
1455 	struct task_struct		*oom_reaper_list;
1456 	struct timer_list		oom_reaper_timer;
1457 #endif
1458 #ifdef CONFIG_VMAP_STACK
1459 	struct vm_struct		*stack_vm_area;
1460 #endif
1461 #ifdef CONFIG_THREAD_INFO_IN_TASK
1462 	/* A live task holds one reference: */
1463 	refcount_t			stack_refcount;
1464 #endif
1465 #ifdef CONFIG_LIVEPATCH
1466 	int patch_state;
1467 #endif
1468 #ifdef CONFIG_SECURITY
1469 	/* Used by LSM modules for access restriction: */
1470 	void				*security;
1471 #endif
1472 #ifdef CONFIG_BPF_SYSCALL
1473 	/* Used by BPF task local storage */
1474 	struct bpf_local_storage __rcu	*bpf_storage;
1475 	/* Used for BPF run context */
1476 	struct bpf_run_ctx		*bpf_ctx;
1477 #endif
1478 
1479 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK
1480 	unsigned long			lowest_stack;
1481 	unsigned long			prev_lowest_stack;
1482 #endif
1483 
1484 #ifdef CONFIG_X86_MCE
1485 	void __user			*mce_vaddr;
1486 	__u64				mce_kflags;
1487 	u64				mce_addr;
1488 	__u64				mce_ripv : 1,
1489 					mce_whole_page : 1,
1490 					__mce_reserved : 62;
1491 	struct callback_head		mce_kill_me;
1492 	int				mce_count;
1493 #endif
1494 	ANDROID_VENDOR_DATA_ARRAY(1, 64);
1495 	ANDROID_OEM_DATA_ARRAY(1, 6);
1496 
1497 #ifdef CONFIG_KRETPROBES
1498 	struct llist_head               kretprobe_instances;
1499 #endif
1500 
1501 #ifdef CONFIG_ARCH_HAS_PARANOID_L1D_FLUSH
1502 	/*
1503 	 * If L1D flush is supported on mm context switch
1504 	 * then we use this callback head to queue kill work
1505 	 * to kill tasks that are not running on SMT disabled
1506 	 * cores
1507 	 */
1508 	struct callback_head		l1d_flush_kill;
1509 #endif
1510 
1511 	ANDROID_KABI_RESERVE(1);
1512 	ANDROID_KABI_RESERVE(2);
1513 	ANDROID_KABI_RESERVE(3);
1514 	ANDROID_KABI_RESERVE(4);
1515 	ANDROID_KABI_RESERVE(5);
1516 	ANDROID_KABI_RESERVE(6);
1517 	ANDROID_KABI_RESERVE(7);
1518 	ANDROID_KABI_RESERVE(8);
1519 
1520 	/*
1521 	 * New fields for task_struct should be added above here, so that
1522 	 * they are included in the randomized portion of task_struct.
1523 	 */
1524 	randomized_struct_fields_end
1525 
1526 	/* CPU-specific state of this task: */
1527 	struct thread_struct		thread;
1528 
1529 	/*
1530 	 * WARNING: on x86, 'thread_struct' contains a variable-sized
1531 	 * structure.  It *MUST* be at the end of 'task_struct'.
1532 	 *
1533 	 * Do not put anything below here!
1534 	 */
1535 };
1536 
task_pid(struct task_struct * task)1537 static inline struct pid *task_pid(struct task_struct *task)
1538 {
1539 	return task->thread_pid;
1540 }
1541 
1542 /*
1543  * the helpers to get the task's different pids as they are seen
1544  * from various namespaces
1545  *
1546  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1547  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1548  *                     current.
1549  * task_xid_nr_ns()  : id seen from the ns specified;
1550  *
1551  * see also pid_nr() etc in include/linux/pid.h
1552  */
1553 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns);
1554 
task_pid_nr(struct task_struct * tsk)1555 static inline pid_t task_pid_nr(struct task_struct *tsk)
1556 {
1557 	return tsk->pid;
1558 }
1559 
task_pid_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1560 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1561 {
1562 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1563 }
1564 
task_pid_vnr(struct task_struct * tsk)1565 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1566 {
1567 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1568 }
1569 
1570 
task_tgid_nr(struct task_struct * tsk)1571 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1572 {
1573 	return tsk->tgid;
1574 }
1575 
1576 /**
1577  * pid_alive - check that a task structure is not stale
1578  * @p: Task structure to be checked.
1579  *
1580  * Test if a process is not yet dead (at most zombie state)
1581  * If pid_alive fails, then pointers within the task structure
1582  * can be stale and must not be dereferenced.
1583  *
1584  * Return: 1 if the process is alive. 0 otherwise.
1585  */
pid_alive(const struct task_struct * p)1586 static inline int pid_alive(const struct task_struct *p)
1587 {
1588 	return p->thread_pid != NULL;
1589 }
1590 
task_pgrp_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1591 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1592 {
1593 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1594 }
1595 
task_pgrp_vnr(struct task_struct * tsk)1596 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1597 {
1598 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1599 }
1600 
1601 
task_session_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1602 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1603 {
1604 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1605 }
1606 
task_session_vnr(struct task_struct * tsk)1607 static inline pid_t task_session_vnr(struct task_struct *tsk)
1608 {
1609 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1610 }
1611 
task_tgid_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1612 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1613 {
1614 	return __task_pid_nr_ns(tsk, PIDTYPE_TGID, ns);
1615 }
1616 
task_tgid_vnr(struct task_struct * tsk)1617 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1618 {
1619 	return __task_pid_nr_ns(tsk, PIDTYPE_TGID, NULL);
1620 }
1621 
task_ppid_nr_ns(const struct task_struct * tsk,struct pid_namespace * ns)1622 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1623 {
1624 	pid_t pid = 0;
1625 
1626 	rcu_read_lock();
1627 	if (pid_alive(tsk))
1628 		pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1629 	rcu_read_unlock();
1630 
1631 	return pid;
1632 }
1633 
task_ppid_nr(const struct task_struct * tsk)1634 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1635 {
1636 	return task_ppid_nr_ns(tsk, &init_pid_ns);
1637 }
1638 
1639 /* Obsolete, do not use: */
task_pgrp_nr(struct task_struct * tsk)1640 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1641 {
1642 	return task_pgrp_nr_ns(tsk, &init_pid_ns);
1643 }
1644 
1645 #define TASK_REPORT_IDLE	(TASK_REPORT + 1)
1646 #define TASK_REPORT_MAX		(TASK_REPORT_IDLE << 1)
1647 
task_state_index(struct task_struct * tsk)1648 static inline unsigned int task_state_index(struct task_struct *tsk)
1649 {
1650 	unsigned int tsk_state = READ_ONCE(tsk->__state);
1651 	unsigned int state = (tsk_state | tsk->exit_state) & TASK_REPORT;
1652 
1653 	BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX);
1654 
1655 	if (tsk_state == TASK_IDLE)
1656 		state = TASK_REPORT_IDLE;
1657 
1658 	/*
1659 	 * We're lying here, but rather than expose a completely new task state
1660 	 * to userspace, we can make this appear as if the task has gone through
1661 	 * a regular rt_mutex_lock() call.
1662 	 */
1663 	if (tsk_state == TASK_RTLOCK_WAIT)
1664 		state = TASK_UNINTERRUPTIBLE;
1665 
1666 	return fls(state);
1667 }
1668 
task_index_to_char(unsigned int state)1669 static inline char task_index_to_char(unsigned int state)
1670 {
1671 	static const char state_char[] = "RSDTtXZPI";
1672 
1673 	BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1);
1674 
1675 	return state_char[state];
1676 }
1677 
task_state_to_char(struct task_struct * tsk)1678 static inline char task_state_to_char(struct task_struct *tsk)
1679 {
1680 	return task_index_to_char(task_state_index(tsk));
1681 }
1682 
1683 /**
1684  * is_global_init - check if a task structure is init. Since init
1685  * is free to have sub-threads we need to check tgid.
1686  * @tsk: Task structure to be checked.
1687  *
1688  * Check if a task structure is the first user space task the kernel created.
1689  *
1690  * Return: 1 if the task structure is init. 0 otherwise.
1691  */
is_global_init(struct task_struct * tsk)1692 static inline int is_global_init(struct task_struct *tsk)
1693 {
1694 	return task_tgid_nr(tsk) == 1;
1695 }
1696 
1697 extern struct pid *cad_pid;
1698 
1699 /*
1700  * Per process flags
1701  */
1702 #define PF_VCPU			0x00000001	/* I'm a virtual CPU */
1703 #define PF_IDLE			0x00000002	/* I am an IDLE thread */
1704 #define PF_EXITING		0x00000004	/* Getting shut down */
1705 #define PF_IO_WORKER		0x00000010	/* Task is an IO worker */
1706 #define PF_WQ_WORKER		0x00000020	/* I'm a workqueue worker */
1707 #define PF_FORKNOEXEC		0x00000040	/* Forked but didn't exec */
1708 #define PF_MCE_PROCESS		0x00000080      /* Process policy on mce errors */
1709 #define PF_SUPERPRIV		0x00000100	/* Used super-user privileges */
1710 #define PF_DUMPCORE		0x00000200	/* Dumped core */
1711 #define PF_SIGNALED		0x00000400	/* Killed by a signal */
1712 #define PF_MEMALLOC		0x00000800	/* Allocating memory */
1713 #define PF_NPROC_EXCEEDED	0x00001000	/* set_user() noticed that RLIMIT_NPROC was exceeded */
1714 #define PF_USED_MATH		0x00002000	/* If unset the fpu must be initialized before use */
1715 #define PF_NOFREEZE		0x00008000	/* This thread should not be frozen */
1716 #define PF_FROZEN		0x00010000	/* Frozen for system suspend */
1717 #define PF_KSWAPD		0x00020000	/* I am kswapd */
1718 #define PF_MEMALLOC_NOFS	0x00040000	/* All allocation requests will inherit GFP_NOFS */
1719 #define PF_MEMALLOC_NOIO	0x00080000	/* All allocation requests will inherit GFP_NOIO */
1720 #define PF_LOCAL_THROTTLE	0x00100000	/* Throttle writes only against the bdi I write to,
1721 						 * I am cleaning dirty pages from some other bdi. */
1722 #define PF_KTHREAD		0x00200000	/* I am a kernel thread */
1723 #define PF_RANDOMIZE		0x00400000	/* Randomize virtual address space */
1724 #define PF_SWAPWRITE		0x00800000	/* Allowed to write to swap */
1725 #define PF_NO_SETAFFINITY	0x04000000	/* Userland is not allowed to meddle with cpus_mask */
1726 #define PF_MCE_EARLY		0x08000000      /* Early kill for mce process policy */
1727 #define PF_MEMALLOC_PIN		0x10000000	/* Allocation context constrained to zones which allow long term pinning. */
1728 #define PF_FREEZER_SKIP		0x40000000	/* Freezer should not count it as freezable */
1729 #define PF_SUSPEND_TASK		0x80000000      /* This thread called freeze_processes() and should not be frozen */
1730 
1731 /*
1732  * Only the _current_ task can read/write to tsk->flags, but other
1733  * tasks can access tsk->flags in readonly mode for example
1734  * with tsk_used_math (like during threaded core dumping).
1735  * There is however an exception to this rule during ptrace
1736  * or during fork: the ptracer task is allowed to write to the
1737  * child->flags of its traced child (same goes for fork, the parent
1738  * can write to the child->flags), because we're guaranteed the
1739  * child is not running and in turn not changing child->flags
1740  * at the same time the parent does it.
1741  */
1742 #define clear_stopped_child_used_math(child)	do { (child)->flags &= ~PF_USED_MATH; } while (0)
1743 #define set_stopped_child_used_math(child)	do { (child)->flags |= PF_USED_MATH; } while (0)
1744 #define clear_used_math()			clear_stopped_child_used_math(current)
1745 #define set_used_math()				set_stopped_child_used_math(current)
1746 
1747 #define conditional_stopped_child_used_math(condition, child) \
1748 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1749 
1750 #define conditional_used_math(condition)	conditional_stopped_child_used_math(condition, current)
1751 
1752 #define copy_to_stopped_child_used_math(child) \
1753 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1754 
1755 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1756 #define tsk_used_math(p)			((p)->flags & PF_USED_MATH)
1757 #define used_math()				tsk_used_math(current)
1758 
is_percpu_thread(void)1759 static __always_inline bool is_percpu_thread(void)
1760 {
1761 #ifdef CONFIG_SMP
1762 	return (current->flags & PF_NO_SETAFFINITY) &&
1763 		(current->nr_cpus_allowed  == 1);
1764 #else
1765 	return true;
1766 #endif
1767 }
1768 
1769 /* Per-process atomic flags. */
1770 #define PFA_NO_NEW_PRIVS		0	/* May not gain new privileges. */
1771 #define PFA_SPREAD_PAGE			1	/* Spread page cache over cpuset */
1772 #define PFA_SPREAD_SLAB			2	/* Spread some slab caches over cpuset */
1773 #define PFA_SPEC_SSB_DISABLE		3	/* Speculative Store Bypass disabled */
1774 #define PFA_SPEC_SSB_FORCE_DISABLE	4	/* Speculative Store Bypass force disabled*/
1775 #define PFA_SPEC_IB_DISABLE		5	/* Indirect branch speculation restricted */
1776 #define PFA_SPEC_IB_FORCE_DISABLE	6	/* Indirect branch speculation permanently restricted */
1777 #define PFA_SPEC_SSB_NOEXEC		7	/* Speculative Store Bypass clear on execve() */
1778 
1779 #define TASK_PFA_TEST(name, func)					\
1780 	static inline bool task_##func(struct task_struct *p)		\
1781 	{ return test_bit(PFA_##name, &p->atomic_flags); }
1782 
1783 #define TASK_PFA_SET(name, func)					\
1784 	static inline void task_set_##func(struct task_struct *p)	\
1785 	{ set_bit(PFA_##name, &p->atomic_flags); }
1786 
1787 #define TASK_PFA_CLEAR(name, func)					\
1788 	static inline void task_clear_##func(struct task_struct *p)	\
1789 	{ clear_bit(PFA_##name, &p->atomic_flags); }
1790 
TASK_PFA_TEST(NO_NEW_PRIVS,no_new_privs)1791 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
1792 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
1793 
1794 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
1795 TASK_PFA_SET(SPREAD_PAGE, spread_page)
1796 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
1797 
1798 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
1799 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
1800 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
1801 
1802 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable)
1803 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable)
1804 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable)
1805 
1806 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1807 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1808 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1809 
1810 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1811 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1812 
1813 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable)
1814 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable)
1815 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable)
1816 
1817 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1818 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1819 
1820 static inline void
1821 current_restore_flags(unsigned long orig_flags, unsigned long flags)
1822 {
1823 	current->flags &= ~flags;
1824 	current->flags |= orig_flags & flags;
1825 }
1826 
1827 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
1828 extern int task_can_attach(struct task_struct *p);
1829 extern int dl_bw_alloc(int cpu, u64 dl_bw);
1830 extern void dl_bw_free(int cpu, u64 dl_bw);
1831 
1832 #ifdef CONFIG_RT_SOFTINT_OPTIMIZATION
1833 extern bool cpupri_check_rt(void);
1834 #else
cpupri_check_rt(void)1835 static inline bool cpupri_check_rt(void)
1836 {
1837 	return false;
1838 }
1839 #endif
1840 
1841 #ifdef CONFIG_SMP
1842 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
1843 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
1844 extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node);
1845 extern void release_user_cpus_ptr(struct task_struct *p);
1846 extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask);
1847 extern void force_compatible_cpus_allowed_ptr(struct task_struct *p);
1848 extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p);
1849 #else
do_set_cpus_allowed(struct task_struct * p,const struct cpumask * new_mask)1850 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
1851 {
1852 }
set_cpus_allowed_ptr(struct task_struct * p,const struct cpumask * new_mask)1853 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
1854 {
1855 	if (!cpumask_test_cpu(0, new_mask))
1856 		return -EINVAL;
1857 	return 0;
1858 }
dup_user_cpus_ptr(struct task_struct * dst,struct task_struct * src,int node)1859 static inline int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node)
1860 {
1861 	if (src->user_cpus_ptr)
1862 		return -EINVAL;
1863 	return 0;
1864 }
release_user_cpus_ptr(struct task_struct * p)1865 static inline void release_user_cpus_ptr(struct task_struct *p)
1866 {
1867 	WARN_ON(p->user_cpus_ptr);
1868 }
1869 
dl_task_check_affinity(struct task_struct * p,const struct cpumask * mask)1870 static inline int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask)
1871 {
1872 	return 0;
1873 }
1874 #endif
1875 
1876 extern int yield_to(struct task_struct *p, bool preempt);
1877 extern void set_user_nice(struct task_struct *p, long nice);
1878 extern int task_prio(const struct task_struct *p);
1879 
1880 /**
1881  * task_nice - return the nice value of a given task.
1882  * @p: the task in question.
1883  *
1884  * Return: The nice value [ -20 ... 0 ... 19 ].
1885  */
task_nice(const struct task_struct * p)1886 static inline int task_nice(const struct task_struct *p)
1887 {
1888 	return PRIO_TO_NICE((p)->static_prio);
1889 }
1890 
1891 extern int can_nice(const struct task_struct *p, const int nice);
1892 extern int task_curr(const struct task_struct *p);
1893 extern int idle_cpu(int cpu);
1894 extern int available_idle_cpu(int cpu);
1895 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *);
1896 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *);
1897 extern void sched_set_fifo(struct task_struct *p);
1898 extern void sched_set_fifo_low(struct task_struct *p);
1899 extern void sched_set_normal(struct task_struct *p, int nice);
1900 extern int sched_setattr(struct task_struct *, const struct sched_attr *);
1901 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *);
1902 extern struct task_struct *idle_task(int cpu);
1903 
1904 /**
1905  * is_idle_task - is the specified task an idle task?
1906  * @p: the task in question.
1907  *
1908  * Return: 1 if @p is an idle task. 0 otherwise.
1909  */
is_idle_task(const struct task_struct * p)1910 static __always_inline bool is_idle_task(const struct task_struct *p)
1911 {
1912 	return !!(p->flags & PF_IDLE);
1913 }
1914 
1915 extern struct task_struct *curr_task(int cpu);
1916 extern void ia64_set_curr_task(int cpu, struct task_struct *p);
1917 
1918 void yield(void);
1919 
1920 union thread_union {
1921 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK
1922 	struct task_struct task;
1923 #endif
1924 #ifndef CONFIG_THREAD_INFO_IN_TASK
1925 	struct thread_info thread_info;
1926 #endif
1927 	unsigned long stack[THREAD_SIZE/sizeof(long)];
1928 };
1929 
1930 #ifndef CONFIG_THREAD_INFO_IN_TASK
1931 extern struct thread_info init_thread_info;
1932 #endif
1933 
1934 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
1935 
1936 #ifdef CONFIG_THREAD_INFO_IN_TASK
task_thread_info(struct task_struct * task)1937 static inline struct thread_info *task_thread_info(struct task_struct *task)
1938 {
1939 	return &task->thread_info;
1940 }
1941 #elif !defined(__HAVE_THREAD_FUNCTIONS)
1942 # define task_thread_info(task)	((struct thread_info *)(task)->stack)
1943 #endif
1944 
1945 /*
1946  * find a task by one of its numerical ids
1947  *
1948  * find_task_by_pid_ns():
1949  *      finds a task by its pid in the specified namespace
1950  * find_task_by_vpid():
1951  *      finds a task by its virtual pid
1952  *
1953  * see also find_vpid() etc in include/linux/pid.h
1954  */
1955 
1956 extern struct task_struct *find_task_by_vpid(pid_t nr);
1957 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns);
1958 
1959 /*
1960  * find a task by its virtual pid and get the task struct
1961  */
1962 extern struct task_struct *find_get_task_by_vpid(pid_t nr);
1963 
1964 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
1965 extern int wake_up_process(struct task_struct *tsk);
1966 extern void wake_up_new_task(struct task_struct *tsk);
1967 
1968 #ifdef CONFIG_SMP
1969 extern void kick_process(struct task_struct *tsk);
1970 #else
kick_process(struct task_struct * tsk)1971 static inline void kick_process(struct task_struct *tsk) { }
1972 #endif
1973 
1974 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
1975 
set_task_comm(struct task_struct * tsk,const char * from)1976 static inline void set_task_comm(struct task_struct *tsk, const char *from)
1977 {
1978 	__set_task_comm(tsk, from, false);
1979 }
1980 
1981 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk);
1982 #define get_task_comm(buf, tsk) ({			\
1983 	BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN);	\
1984 	__get_task_comm(buf, sizeof(buf), tsk);		\
1985 })
1986 
1987 #ifdef CONFIG_SMP
scheduler_ipi(void)1988 static __always_inline void scheduler_ipi(void)
1989 {
1990 	/*
1991 	 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting
1992 	 * TIF_NEED_RESCHED remotely (for the first time) will also send
1993 	 * this IPI.
1994 	 */
1995 	preempt_fold_need_resched();
1996 }
1997 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state);
1998 #else
scheduler_ipi(void)1999 static inline void scheduler_ipi(void) { }
wait_task_inactive(struct task_struct * p,unsigned int match_state)2000 static inline unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state)
2001 {
2002 	return 1;
2003 }
2004 #endif
2005 
2006 /*
2007  * Set thread flags in other task's structures.
2008  * See asm/thread_info.h for TIF_xxxx flags available:
2009  */
set_tsk_thread_flag(struct task_struct * tsk,int flag)2010 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2011 {
2012 	set_ti_thread_flag(task_thread_info(tsk), flag);
2013 }
2014 
clear_tsk_thread_flag(struct task_struct * tsk,int flag)2015 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2016 {
2017 	clear_ti_thread_flag(task_thread_info(tsk), flag);
2018 }
2019 
update_tsk_thread_flag(struct task_struct * tsk,int flag,bool value)2020 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag,
2021 					  bool value)
2022 {
2023 	update_ti_thread_flag(task_thread_info(tsk), flag, value);
2024 }
2025 
test_and_set_tsk_thread_flag(struct task_struct * tsk,int flag)2026 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2027 {
2028 	return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2029 }
2030 
test_and_clear_tsk_thread_flag(struct task_struct * tsk,int flag)2031 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2032 {
2033 	return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2034 }
2035 
test_tsk_thread_flag(struct task_struct * tsk,int flag)2036 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2037 {
2038 	return test_ti_thread_flag(task_thread_info(tsk), flag);
2039 }
2040 
set_tsk_need_resched(struct task_struct * tsk)2041 static inline void set_tsk_need_resched(struct task_struct *tsk)
2042 {
2043 	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2044 }
2045 
clear_tsk_need_resched(struct task_struct * tsk)2046 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2047 {
2048 	clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2049 }
2050 
test_tsk_need_resched(struct task_struct * tsk)2051 static inline int test_tsk_need_resched(struct task_struct *tsk)
2052 {
2053 	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2054 }
2055 
2056 /*
2057  * cond_resched() and cond_resched_lock(): latency reduction via
2058  * explicit rescheduling in places that are safe. The return
2059  * value indicates whether a reschedule was done in fact.
2060  * cond_resched_lock() will drop the spinlock before scheduling,
2061  */
2062 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC)
2063 extern int __cond_resched(void);
2064 
2065 #ifdef CONFIG_PREEMPT_DYNAMIC
2066 
2067 DECLARE_STATIC_CALL(cond_resched, __cond_resched);
2068 
_cond_resched(void)2069 static __always_inline int _cond_resched(void)
2070 {
2071 	return static_call_mod(cond_resched)();
2072 }
2073 
2074 #else
2075 
_cond_resched(void)2076 static inline int _cond_resched(void)
2077 {
2078 	return __cond_resched();
2079 }
2080 
2081 #endif /* CONFIG_PREEMPT_DYNAMIC */
2082 
2083 #else
2084 
_cond_resched(void)2085 static inline int _cond_resched(void) { return 0; }
2086 
2087 #endif /* !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) */
2088 
2089 #define cond_resched() ({			\
2090 	___might_sleep(__FILE__, __LINE__, 0);	\
2091 	_cond_resched();			\
2092 })
2093 
2094 extern int __cond_resched_lock(spinlock_t *lock);
2095 extern int __cond_resched_rwlock_read(rwlock_t *lock);
2096 extern int __cond_resched_rwlock_write(rwlock_t *lock);
2097 
2098 #define cond_resched_lock(lock) ({				\
2099 	___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
2100 	__cond_resched_lock(lock);				\
2101 })
2102 
2103 #define cond_resched_rwlock_read(lock) ({			\
2104 	__might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);	\
2105 	__cond_resched_rwlock_read(lock);			\
2106 })
2107 
2108 #define cond_resched_rwlock_write(lock) ({			\
2109 	__might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);	\
2110 	__cond_resched_rwlock_write(lock);			\
2111 })
2112 
cond_resched_rcu(void)2113 static inline void cond_resched_rcu(void)
2114 {
2115 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
2116 	rcu_read_unlock();
2117 	cond_resched();
2118 	rcu_read_lock();
2119 #endif
2120 }
2121 
2122 /*
2123  * Does a critical section need to be broken due to another
2124  * task waiting?: (technically does not depend on CONFIG_PREEMPTION,
2125  * but a general need for low latency)
2126  */
spin_needbreak(spinlock_t * lock)2127 static inline int spin_needbreak(spinlock_t *lock)
2128 {
2129 #ifdef CONFIG_PREEMPTION
2130 	return spin_is_contended(lock);
2131 #else
2132 	return 0;
2133 #endif
2134 }
2135 
2136 /*
2137  * Check if a rwlock is contended.
2138  * Returns non-zero if there is another task waiting on the rwlock.
2139  * Returns zero if the lock is not contended or the system / underlying
2140  * rwlock implementation does not support contention detection.
2141  * Technically does not depend on CONFIG_PREEMPTION, but a general need
2142  * for low latency.
2143  */
rwlock_needbreak(rwlock_t * lock)2144 static inline int rwlock_needbreak(rwlock_t *lock)
2145 {
2146 #ifdef CONFIG_PREEMPTION
2147 	return rwlock_is_contended(lock);
2148 #else
2149 	return 0;
2150 #endif
2151 }
2152 
need_resched(void)2153 static __always_inline bool need_resched(void)
2154 {
2155 	return unlikely(tif_need_resched());
2156 }
2157 
2158 /*
2159  * Wrappers for p->thread_info->cpu access. No-op on UP.
2160  */
2161 #ifdef CONFIG_SMP
2162 
task_cpu(const struct task_struct * p)2163 static inline unsigned int task_cpu(const struct task_struct *p)
2164 {
2165 #ifdef CONFIG_THREAD_INFO_IN_TASK
2166 	return READ_ONCE(p->cpu);
2167 #else
2168 	return READ_ONCE(task_thread_info(p)->cpu);
2169 #endif
2170 }
2171 
2172 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2173 
2174 #else
2175 
task_cpu(const struct task_struct * p)2176 static inline unsigned int task_cpu(const struct task_struct *p)
2177 {
2178 	return 0;
2179 }
2180 
set_task_cpu(struct task_struct * p,unsigned int cpu)2181 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2182 {
2183 }
2184 
2185 #endif /* CONFIG_SMP */
2186 
2187 extern bool sched_task_on_rq(struct task_struct *p);
2188 
2189 /*
2190  * In order to reduce various lock holder preemption latencies provide an
2191  * interface to see if a vCPU is currently running or not.
2192  *
2193  * This allows us to terminate optimistic spin loops and block, analogous to
2194  * the native optimistic spin heuristic of testing if the lock owner task is
2195  * running or not.
2196  */
2197 #ifndef vcpu_is_preempted
vcpu_is_preempted(int cpu)2198 static inline bool vcpu_is_preempted(int cpu)
2199 {
2200 	return false;
2201 }
2202 #endif
2203 
2204 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2205 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2206 
2207 #ifndef TASK_SIZE_OF
2208 #define TASK_SIZE_OF(tsk)	TASK_SIZE
2209 #endif
2210 
2211 #ifdef CONFIG_SMP
2212 /* Returns effective CPU energy utilization, as seen by the scheduler */
2213 unsigned long sched_cpu_util(int cpu, unsigned long max);
2214 #endif /* CONFIG_SMP */
2215 
2216 #ifdef CONFIG_RSEQ
2217 
2218 /*
2219  * Map the event mask on the user-space ABI enum rseq_cs_flags
2220  * for direct mask checks.
2221  */
2222 enum rseq_event_mask_bits {
2223 	RSEQ_EVENT_PREEMPT_BIT	= RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT,
2224 	RSEQ_EVENT_SIGNAL_BIT	= RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT,
2225 	RSEQ_EVENT_MIGRATE_BIT	= RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT,
2226 };
2227 
2228 enum rseq_event_mask {
2229 	RSEQ_EVENT_PREEMPT	= (1U << RSEQ_EVENT_PREEMPT_BIT),
2230 	RSEQ_EVENT_SIGNAL	= (1U << RSEQ_EVENT_SIGNAL_BIT),
2231 	RSEQ_EVENT_MIGRATE	= (1U << RSEQ_EVENT_MIGRATE_BIT),
2232 };
2233 
rseq_set_notify_resume(struct task_struct * t)2234 static inline void rseq_set_notify_resume(struct task_struct *t)
2235 {
2236 	if (t->rseq)
2237 		set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
2238 }
2239 
2240 void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs);
2241 
rseq_handle_notify_resume(struct ksignal * ksig,struct pt_regs * regs)2242 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
2243 					     struct pt_regs *regs)
2244 {
2245 	if (current->rseq)
2246 		__rseq_handle_notify_resume(ksig, regs);
2247 }
2248 
rseq_signal_deliver(struct ksignal * ksig,struct pt_regs * regs)2249 static inline void rseq_signal_deliver(struct ksignal *ksig,
2250 				       struct pt_regs *regs)
2251 {
2252 	preempt_disable();
2253 	__set_bit(RSEQ_EVENT_SIGNAL_BIT, &current->rseq_event_mask);
2254 	preempt_enable();
2255 	rseq_handle_notify_resume(ksig, regs);
2256 }
2257 
2258 /* rseq_preempt() requires preemption to be disabled. */
rseq_preempt(struct task_struct * t)2259 static inline void rseq_preempt(struct task_struct *t)
2260 {
2261 	__set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask);
2262 	rseq_set_notify_resume(t);
2263 }
2264 
2265 /* rseq_migrate() requires preemption to be disabled. */
rseq_migrate(struct task_struct * t)2266 static inline void rseq_migrate(struct task_struct *t)
2267 {
2268 	__set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask);
2269 	rseq_set_notify_resume(t);
2270 }
2271 
2272 /*
2273  * If parent process has a registered restartable sequences area, the
2274  * child inherits. Unregister rseq for a clone with CLONE_VM set.
2275  */
rseq_fork(struct task_struct * t,unsigned long clone_flags)2276 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
2277 {
2278 	if (clone_flags & CLONE_VM) {
2279 		t->rseq = NULL;
2280 		t->rseq_sig = 0;
2281 		t->rseq_event_mask = 0;
2282 	} else {
2283 		t->rseq = current->rseq;
2284 		t->rseq_sig = current->rseq_sig;
2285 		t->rseq_event_mask = current->rseq_event_mask;
2286 	}
2287 }
2288 
rseq_execve(struct task_struct * t)2289 static inline void rseq_execve(struct task_struct *t)
2290 {
2291 	t->rseq = NULL;
2292 	t->rseq_sig = 0;
2293 	t->rseq_event_mask = 0;
2294 }
2295 
2296 #else
2297 
rseq_set_notify_resume(struct task_struct * t)2298 static inline void rseq_set_notify_resume(struct task_struct *t)
2299 {
2300 }
rseq_handle_notify_resume(struct ksignal * ksig,struct pt_regs * regs)2301 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
2302 					     struct pt_regs *regs)
2303 {
2304 }
rseq_signal_deliver(struct ksignal * ksig,struct pt_regs * regs)2305 static inline void rseq_signal_deliver(struct ksignal *ksig,
2306 				       struct pt_regs *regs)
2307 {
2308 }
rseq_preempt(struct task_struct * t)2309 static inline void rseq_preempt(struct task_struct *t)
2310 {
2311 }
rseq_migrate(struct task_struct * t)2312 static inline void rseq_migrate(struct task_struct *t)
2313 {
2314 }
rseq_fork(struct task_struct * t,unsigned long clone_flags)2315 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
2316 {
2317 }
rseq_execve(struct task_struct * t)2318 static inline void rseq_execve(struct task_struct *t)
2319 {
2320 }
2321 
2322 #endif
2323 
2324 #ifdef CONFIG_DEBUG_RSEQ
2325 
2326 void rseq_syscall(struct pt_regs *regs);
2327 
2328 #else
2329 
rseq_syscall(struct pt_regs * regs)2330 static inline void rseq_syscall(struct pt_regs *regs)
2331 {
2332 }
2333 
2334 #endif
2335 
2336 const struct sched_avg *sched_trace_cfs_rq_avg(struct cfs_rq *cfs_rq);
2337 char *sched_trace_cfs_rq_path(struct cfs_rq *cfs_rq, char *str, int len);
2338 int sched_trace_cfs_rq_cpu(struct cfs_rq *cfs_rq);
2339 
2340 const struct sched_avg *sched_trace_rq_avg_rt(struct rq *rq);
2341 const struct sched_avg *sched_trace_rq_avg_dl(struct rq *rq);
2342 const struct sched_avg *sched_trace_rq_avg_irq(struct rq *rq);
2343 
2344 int sched_trace_rq_cpu(struct rq *rq);
2345 int sched_trace_rq_cpu_capacity(struct rq *rq);
2346 int sched_trace_rq_nr_running(struct rq *rq);
2347 
2348 const struct cpumask *sched_trace_rd_span(struct root_domain *rd);
2349 
2350 #ifdef CONFIG_SCHED_CORE
2351 extern void sched_core_free(struct task_struct *tsk);
2352 extern void sched_core_fork(struct task_struct *p);
2353 extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type,
2354 				unsigned long uaddr);
2355 #else
sched_core_free(struct task_struct * tsk)2356 static inline void sched_core_free(struct task_struct *tsk) { }
sched_core_fork(struct task_struct * p)2357 static inline void sched_core_fork(struct task_struct *p) { }
2358 #endif
2359 
2360 #endif
2361