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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/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 seq_file;
67 struct sighand_struct;
68 struct signal_struct;
69 struct task_delay_info;
70 struct task_group;
71 struct user_event_mm;
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			0x00000000
86 #define TASK_INTERRUPTIBLE		0x00000001
87 #define TASK_UNINTERRUPTIBLE		0x00000002
88 #define __TASK_STOPPED			0x00000004
89 #define __TASK_TRACED			0x00000008
90 /* Used in tsk->exit_state: */
91 #define EXIT_DEAD			0x00000010
92 #define EXIT_ZOMBIE			0x00000020
93 #define EXIT_TRACE			(EXIT_ZOMBIE | EXIT_DEAD)
94 /* Used in tsk->__state again: */
95 #define TASK_PARKED			0x00000040
96 #define TASK_DEAD			0x00000080
97 #define TASK_WAKEKILL			0x00000100
98 #define TASK_WAKING			0x00000200
99 #define TASK_NOLOAD			0x00000400
100 #define TASK_NEW			0x00000800
101 #define TASK_RTLOCK_WAIT		0x00001000
102 #define TASK_FREEZABLE			0x00002000
103 #define __TASK_FREEZABLE_UNSAFE	       (0x00004000 * IS_ENABLED(CONFIG_LOCKDEP))
104 #define TASK_FROZEN			0x00008000
105 #define TASK_STATE_MAX			0x00010000
106 
107 #define TASK_ANY			(TASK_STATE_MAX-1)
108 
109 /*
110  * DO NOT ADD ANY NEW USERS !
111  */
112 #define TASK_FREEZABLE_UNSAFE		(TASK_FREEZABLE | __TASK_FREEZABLE_UNSAFE)
113 
114 /* Convenience macros for the sake of set_current_state: */
115 #define TASK_KILLABLE			(TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
116 #define TASK_STOPPED			(TASK_WAKEKILL | __TASK_STOPPED)
117 #define TASK_TRACED			__TASK_TRACED
118 
119 #define TASK_IDLE			(TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
120 
121 /* Convenience macros for the sake of wake_up(): */
122 #define TASK_NORMAL			(TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
123 
124 /* get_task_state(): */
125 #define TASK_REPORT			(TASK_RUNNING | TASK_INTERRUPTIBLE | \
126 					 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
127 					 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
128 					 TASK_PARKED)
129 
130 #define task_is_running(task)		(READ_ONCE((task)->__state) == TASK_RUNNING)
131 
132 #define task_is_traced(task)		((READ_ONCE(task->jobctl) & JOBCTL_TRACED) != 0)
133 #define task_is_stopped(task)		((READ_ONCE(task->jobctl) & JOBCTL_STOPPED) != 0)
134 #define task_is_stopped_or_traced(task)	((READ_ONCE(task->jobctl) & (JOBCTL_STOPPED | JOBCTL_TRACED)) != 0)
135 
136 /*
137  * Special states are those that do not use the normal wait-loop pattern. See
138  * the comment with set_special_state().
139  */
140 #define is_special_task_state(state)				\
141 	((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD))
142 
143 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
144 # define debug_normal_state_change(state_value)				\
145 	do {								\
146 		WARN_ON_ONCE(is_special_task_state(state_value));	\
147 		current->task_state_change = _THIS_IP_;			\
148 	} while (0)
149 
150 # define debug_special_state_change(state_value)			\
151 	do {								\
152 		WARN_ON_ONCE(!is_special_task_state(state_value));	\
153 		current->task_state_change = _THIS_IP_;			\
154 	} while (0)
155 
156 # define debug_rtlock_wait_set_state()					\
157 	do {								 \
158 		current->saved_state_change = current->task_state_change;\
159 		current->task_state_change = _THIS_IP_;			 \
160 	} while (0)
161 
162 # define debug_rtlock_wait_restore_state()				\
163 	do {								 \
164 		current->task_state_change = current->saved_state_change;\
165 	} while (0)
166 
167 #else
168 # define debug_normal_state_change(cond)	do { } while (0)
169 # define debug_special_state_change(cond)	do { } while (0)
170 # define debug_rtlock_wait_set_state()		do { } while (0)
171 # define debug_rtlock_wait_restore_state()	do { } while (0)
172 #endif
173 
174 /*
175  * set_current_state() includes a barrier so that the write of current->__state
176  * is correctly serialised wrt the caller's subsequent test of whether to
177  * actually sleep:
178  *
179  *   for (;;) {
180  *	set_current_state(TASK_UNINTERRUPTIBLE);
181  *	if (CONDITION)
182  *	   break;
183  *
184  *	schedule();
185  *   }
186  *   __set_current_state(TASK_RUNNING);
187  *
188  * If the caller does not need such serialisation (because, for instance, the
189  * CONDITION test and condition change and wakeup are under the same lock) then
190  * use __set_current_state().
191  *
192  * The above is typically ordered against the wakeup, which does:
193  *
194  *   CONDITION = 1;
195  *   wake_up_state(p, TASK_UNINTERRUPTIBLE);
196  *
197  * where wake_up_state()/try_to_wake_up() executes a full memory barrier before
198  * accessing p->__state.
199  *
200  * Wakeup will do: if (@state & p->__state) p->__state = TASK_RUNNING, that is,
201  * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
202  * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
203  *
204  * However, with slightly different timing the wakeup TASK_RUNNING store can
205  * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not
206  * a problem either because that will result in one extra go around the loop
207  * and our @cond test will save the day.
208  *
209  * Also see the comments of try_to_wake_up().
210  */
211 #define __set_current_state(state_value)				\
212 	do {								\
213 		debug_normal_state_change((state_value));		\
214 		WRITE_ONCE(current->__state, (state_value));		\
215 	} while (0)
216 
217 #define set_current_state(state_value)					\
218 	do {								\
219 		debug_normal_state_change((state_value));		\
220 		smp_store_mb(current->__state, (state_value));		\
221 	} while (0)
222 
223 /*
224  * set_special_state() should be used for those states when the blocking task
225  * can not use the regular condition based wait-loop. In that case we must
226  * serialize against wakeups such that any possible in-flight TASK_RUNNING
227  * stores will not collide with our state change.
228  */
229 #define set_special_state(state_value)					\
230 	do {								\
231 		unsigned long flags; /* may shadow */			\
232 									\
233 		raw_spin_lock_irqsave(&current->pi_lock, flags);	\
234 		debug_special_state_change((state_value));		\
235 		WRITE_ONCE(current->__state, (state_value));		\
236 		raw_spin_unlock_irqrestore(&current->pi_lock, flags);	\
237 	} while (0)
238 
239 /*
240  * PREEMPT_RT specific variants for "sleeping" spin/rwlocks
241  *
242  * RT's spin/rwlock substitutions are state preserving. The state of the
243  * task when blocking on the lock is saved in task_struct::saved_state and
244  * restored after the lock has been acquired.  These operations are
245  * serialized by task_struct::pi_lock against try_to_wake_up(). Any non RT
246  * lock related wakeups while the task is blocked on the lock are
247  * redirected to operate on task_struct::saved_state to ensure that these
248  * are not dropped. On restore task_struct::saved_state is set to
249  * TASK_RUNNING so any wakeup attempt redirected to saved_state will fail.
250  *
251  * The lock operation looks like this:
252  *
253  *	current_save_and_set_rtlock_wait_state();
254  *	for (;;) {
255  *		if (try_lock())
256  *			break;
257  *		raw_spin_unlock_irq(&lock->wait_lock);
258  *		schedule_rtlock();
259  *		raw_spin_lock_irq(&lock->wait_lock);
260  *		set_current_state(TASK_RTLOCK_WAIT);
261  *	}
262  *	current_restore_rtlock_saved_state();
263  */
264 #define current_save_and_set_rtlock_wait_state()			\
265 	do {								\
266 		lockdep_assert_irqs_disabled();				\
267 		raw_spin_lock(&current->pi_lock);			\
268 		current->saved_state = current->__state;		\
269 		debug_rtlock_wait_set_state();				\
270 		WRITE_ONCE(current->__state, TASK_RTLOCK_WAIT);		\
271 		raw_spin_unlock(&current->pi_lock);			\
272 	} while (0);
273 
274 #define current_restore_rtlock_saved_state()				\
275 	do {								\
276 		lockdep_assert_irqs_disabled();				\
277 		raw_spin_lock(&current->pi_lock);			\
278 		debug_rtlock_wait_restore_state();			\
279 		WRITE_ONCE(current->__state, current->saved_state);	\
280 		current->saved_state = TASK_RUNNING;			\
281 		raw_spin_unlock(&current->pi_lock);			\
282 	} while (0);
283 
284 #define get_current_state()	READ_ONCE(current->__state)
285 
286 /*
287  * Define the task command name length as enum, then it can be visible to
288  * BPF programs.
289  */
290 enum {
291 	TASK_COMM_LEN = 16,
292 };
293 enum task_event {
294 	PUT_PREV_TASK   = 0,
295 	PICK_NEXT_TASK  = 1,
296 	TASK_WAKE       = 2,
297 	TASK_MIGRATE    = 3,
298 	TASK_UPDATE     = 4,
299 	IRQ_UPDATE      = 5,
300 };
301 
302 /* Note: this need to be in sync with migrate_type_names array */
303 enum migrate_types {
304 	GROUP_TO_RQ,
305 	RQ_TO_GROUP,
306 };
307 
308 #ifdef CONFIG_CPU_ISOLATION_OPT
309 extern int sched_isolate_count(const cpumask_t *mask, bool include_offline);
310 extern int sched_isolate_cpu(int cpu);
311 extern int sched_unisolate_cpu(int cpu);
312 extern int sched_unisolate_cpu_unlocked(int cpu);
313 #else
sched_isolate_count(const cpumask_t * mask,bool include_offline)314 static inline int sched_isolate_count(const cpumask_t *mask,
315 				      bool include_offline)
316 {
317 	cpumask_t count_mask;
318 
319 	if (include_offline)
320 		cpumask_andnot(&count_mask, mask, cpu_online_mask);
321 	else
322 		return 0;
323 
324 	return cpumask_weight(&count_mask);
325 }
326 
sched_isolate_cpu(int cpu)327 static inline int sched_isolate_cpu(int cpu)
328 {
329 	return 0;
330 }
331 
sched_unisolate_cpu(int cpu)332 static inline int sched_unisolate_cpu(int cpu)
333 {
334 	return 0;
335 }
336 
sched_unisolate_cpu_unlocked(int cpu)337 static inline int sched_unisolate_cpu_unlocked(int cpu)
338 {
339 	return 0;
340 }
341 #endif
342 
343 extern void scheduler_tick(void);
344 
345 #define	MAX_SCHEDULE_TIMEOUT		LONG_MAX
346 
347 extern long schedule_timeout(long timeout);
348 extern long schedule_timeout_interruptible(long timeout);
349 extern long schedule_timeout_killable(long timeout);
350 extern long schedule_timeout_uninterruptible(long timeout);
351 extern long schedule_timeout_idle(long timeout);
352 asmlinkage void schedule(void);
353 extern void schedule_preempt_disabled(void);
354 asmlinkage void preempt_schedule_irq(void);
355 #ifdef CONFIG_PREEMPT_RT
356  extern void schedule_rtlock(void);
357 #endif
358 
359 extern int __must_check io_schedule_prepare(void);
360 extern void io_schedule_finish(int token);
361 extern long io_schedule_timeout(long timeout);
362 extern void io_schedule(void);
363 
364 /**
365  * struct prev_cputime - snapshot of system and user cputime
366  * @utime: time spent in user mode
367  * @stime: time spent in system mode
368  * @lock: protects the above two fields
369  *
370  * Stores previous user/system time values such that we can guarantee
371  * monotonicity.
372  */
373 struct prev_cputime {
374 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
375 	u64				utime;
376 	u64				stime;
377 	raw_spinlock_t			lock;
378 #endif
379 };
380 
381 enum vtime_state {
382 	/* Task is sleeping or running in a CPU with VTIME inactive: */
383 	VTIME_INACTIVE = 0,
384 	/* Task is idle */
385 	VTIME_IDLE,
386 	/* Task runs in kernelspace in a CPU with VTIME active: */
387 	VTIME_SYS,
388 	/* Task runs in userspace in a CPU with VTIME active: */
389 	VTIME_USER,
390 	/* Task runs as guests in a CPU with VTIME active: */
391 	VTIME_GUEST,
392 };
393 
394 struct vtime {
395 	seqcount_t		seqcount;
396 	unsigned long long	starttime;
397 	enum vtime_state	state;
398 	unsigned int		cpu;
399 	u64			utime;
400 	u64			stime;
401 	u64			gtime;
402 };
403 
404 /*
405  * Utilization clamp constraints.
406  * @UCLAMP_MIN:	Minimum utilization
407  * @UCLAMP_MAX:	Maximum utilization
408  * @UCLAMP_CNT:	Utilization clamp constraints count
409  */
410 enum uclamp_id {
411 	UCLAMP_MIN = 0,
412 	UCLAMP_MAX,
413 	UCLAMP_CNT
414 };
415 
416 #ifdef CONFIG_SMP
417 extern struct root_domain def_root_domain;
418 extern struct mutex sched_domains_mutex;
419 #endif
420 
421 struct sched_param {
422 	int sched_priority;
423 };
424 
425 struct sched_info {
426 #ifdef CONFIG_SCHED_INFO
427 	/* Cumulative counters: */
428 
429 	/* # of times we have run on this CPU: */
430 	unsigned long			pcount;
431 
432 	/* Time spent waiting on a runqueue: */
433 	unsigned long long		run_delay;
434 
435 	/* Timestamps: */
436 
437 	/* When did we last run on a CPU? */
438 	unsigned long long		last_arrival;
439 
440 	/* When were we last queued to run? */
441 	unsigned long long		last_queued;
442 
443 #endif /* CONFIG_SCHED_INFO */
444 };
445 
446 /*
447  * Integer metrics need fixed point arithmetic, e.g., sched/fair
448  * has a few: load, load_avg, util_avg, freq, and capacity.
449  *
450  * We define a basic fixed point arithmetic range, and then formalize
451  * all these metrics based on that basic range.
452  */
453 # define SCHED_FIXEDPOINT_SHIFT		10
454 # define SCHED_FIXEDPOINT_SCALE		(1L << SCHED_FIXEDPOINT_SHIFT)
455 
456 /* Increase resolution of cpu_capacity calculations */
457 # define SCHED_CAPACITY_SHIFT		SCHED_FIXEDPOINT_SHIFT
458 # define SCHED_CAPACITY_SCALE		(1L << SCHED_CAPACITY_SHIFT)
459 
460 struct load_weight {
461 	unsigned long			weight;
462 	u32				inv_weight;
463 };
464 
465 /**
466  * struct util_est - Estimation utilization of FAIR tasks
467  * @enqueued: instantaneous estimated utilization of a task/cpu
468  * @ewma:     the Exponential Weighted Moving Average (EWMA)
469  *            utilization of a task
470  *
471  * Support data structure to track an Exponential Weighted Moving Average
472  * (EWMA) of a FAIR task's utilization. New samples are added to the moving
473  * average each time a task completes an activation. Sample's weight is chosen
474  * so that the EWMA will be relatively insensitive to transient changes to the
475  * task's workload.
476  *
477  * The enqueued attribute has a slightly different meaning for tasks and cpus:
478  * - task:   the task's util_avg at last task dequeue time
479  * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU
480  * Thus, the util_est.enqueued of a task represents the contribution on the
481  * estimated utilization of the CPU where that task is currently enqueued.
482  *
483  * Only for tasks we track a moving average of the past instantaneous
484  * estimated utilization. This allows to absorb sporadic drops in utilization
485  * of an otherwise almost periodic task.
486  *
487  * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg
488  * updates. When a task is dequeued, its util_est should not be updated if its
489  * util_avg has not been updated in the meantime.
490  * This information is mapped into the MSB bit of util_est.enqueued at dequeue
491  * time. Since max value of util_est.enqueued for a task is 1024 (PELT util_avg
492  * for a task) it is safe to use MSB.
493  */
494 struct util_est {
495 	unsigned int			enqueued;
496 	unsigned int			ewma;
497 #define UTIL_EST_WEIGHT_SHIFT		2
498 #define UTIL_AVG_UNCHANGED		0x80000000
499 } __attribute__((__aligned__(sizeof(u64))));
500 
501 /*
502  * The load/runnable/util_avg accumulates an infinite geometric series
503  * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c).
504  *
505  * [load_avg definition]
506  *
507  *   load_avg = runnable% * scale_load_down(load)
508  *
509  * [runnable_avg definition]
510  *
511  *   runnable_avg = runnable% * SCHED_CAPACITY_SCALE
512  *
513  * [util_avg definition]
514  *
515  *   util_avg = running% * SCHED_CAPACITY_SCALE
516  *
517  * where runnable% is the time ratio that a sched_entity is runnable and
518  * running% the time ratio that a sched_entity is running.
519  *
520  * For cfs_rq, they are the aggregated values of all runnable and blocked
521  * sched_entities.
522  *
523  * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU
524  * capacity scaling. The scaling is done through the rq_clock_pelt that is used
525  * for computing those signals (see update_rq_clock_pelt())
526  *
527  * N.B., the above ratios (runnable% and running%) themselves are in the
528  * range of [0, 1]. To do fixed point arithmetics, we therefore scale them
529  * to as large a range as necessary. This is for example reflected by
530  * util_avg's SCHED_CAPACITY_SCALE.
531  *
532  * [Overflow issue]
533  *
534  * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
535  * with the highest load (=88761), always runnable on a single cfs_rq,
536  * and should not overflow as the number already hits PID_MAX_LIMIT.
537  *
538  * For all other cases (including 32-bit kernels), struct load_weight's
539  * weight will overflow first before we do, because:
540  *
541  *    Max(load_avg) <= Max(load.weight)
542  *
543  * Then it is the load_weight's responsibility to consider overflow
544  * issues.
545  */
546 struct sched_avg {
547 	u64				last_update_time;
548 	u64				load_sum;
549 	u64				runnable_sum;
550 	u32				util_sum;
551 	u32				period_contrib;
552 	unsigned long			load_avg;
553 	unsigned long			runnable_avg;
554 	unsigned long			util_avg;
555 	struct util_est			util_est;
556 } ____cacheline_aligned;
557 
558 struct sched_statistics {
559 #ifdef CONFIG_SCHEDSTATS
560 	u64				wait_start;
561 	u64				wait_max;
562 	u64				wait_count;
563 	u64				wait_sum;
564 	u64				iowait_count;
565 	u64				iowait_sum;
566 
567 	u64				sleep_start;
568 	u64				sleep_max;
569 	s64				sum_sleep_runtime;
570 
571 	u64				block_start;
572 	u64				block_max;
573 	s64				sum_block_runtime;
574 
575 	s64				exec_max;
576 	u64				slice_max;
577 
578 	u64				nr_migrations_cold;
579 	u64				nr_failed_migrations_affine;
580 	u64				nr_failed_migrations_running;
581 	u64				nr_failed_migrations_hot;
582 	u64				nr_forced_migrations;
583 
584 	u64				nr_wakeups;
585 	u64				nr_wakeups_sync;
586 	u64				nr_wakeups_migrate;
587 	u64				nr_wakeups_local;
588 	u64				nr_wakeups_remote;
589 	u64				nr_wakeups_affine;
590 	u64				nr_wakeups_affine_attempts;
591 	u64				nr_wakeups_passive;
592 	u64				nr_wakeups_idle;
593 
594 #ifdef CONFIG_SCHED_CORE
595 	u64				core_forceidle_sum;
596 #endif
597 #endif /* CONFIG_SCHEDSTATS */
598 } ____cacheline_aligned;
599 
600 struct sched_entity {
601 	/* For load-balancing: */
602 	struct load_weight		load;
603 	struct rb_node			run_node;
604 	u64				deadline;
605 	u64				min_deadline;
606 
607 	struct list_head		group_node;
608 	unsigned int			on_rq;
609 
610 	u64				exec_start;
611 	u64				sum_exec_runtime;
612 	u64				prev_sum_exec_runtime;
613 	u64				vruntime;
614 	s64				vlag;
615 	u64				slice;
616 
617 	u64				nr_migrations;
618 
619 #ifdef CONFIG_FAIR_GROUP_SCHED
620 	int				depth;
621 	struct sched_entity		*parent;
622 	/* rq on which this entity is (to be) queued: */
623 	struct cfs_rq			*cfs_rq;
624 	/* rq "owned" by this entity/group: */
625 	struct cfs_rq			*my_q;
626 	/* cached value of my_q->h_nr_running */
627 	unsigned long			runnable_weight;
628 #endif
629 
630 #ifdef CONFIG_SCHED_LATENCY_NICE
631 	int				latency_weight;
632 #endif
633 
634 #ifdef CONFIG_SMP
635 	/*
636 	 * Per entity load average tracking.
637 	 *
638 	 * Put into separate cache line so it does not
639 	 * collide with read-mostly values above.
640 	 */
641 	struct sched_avg		avg;
642 #endif
643 };
644 
645 #ifdef CONFIG_SCHED_WALT
646 extern void sched_exit(struct task_struct *p);
647 extern int sched_set_init_task_load(struct task_struct *p, int init_load_pct);
648 extern u32 sched_get_init_task_load(struct task_struct *p);
649 extern void free_task_load_ptrs(struct task_struct *p);
650 #define RAVG_HIST_SIZE_MAX  5
651 struct ravg {
652 	/*
653 	 * 'mark_start' marks the beginning of an event (task waking up, task
654 	 * starting to execute, task being preempted) within a window
655 	 *
656 	 * 'sum' represents how runnable a task has been within current
657 	 * window. It incorporates both running time and wait time and is
658 	 * frequency scaled.
659 	 *
660 	 * 'sum_history' keeps track of history of 'sum' seen over previous
661 	 * RAVG_HIST_SIZE windows. Windows where task was entirely sleeping are
662 	 * ignored.
663 	 *
664 	 * 'demand' represents maximum sum seen over previous
665 	 * sysctl_sched_ravg_hist_size windows. 'demand' could drive frequency
666 	 * demand for tasks.
667 	 *
668 	 * 'curr_window_cpu' represents task's contribution to cpu busy time on
669 	 * various CPUs in the current window
670 	 *
671 	 * 'prev_window_cpu' represents task's contribution to cpu busy time on
672 	 * various CPUs in the previous window
673 	 *
674 	 * 'curr_window' represents the sum of all entries in curr_window_cpu
675 	 *
676 	 * 'prev_window' represents the sum of all entries in prev_window_cpu
677 	 *
678 	 */
679 	u64 mark_start;
680 	u32 sum, demand;
681 	u32 sum_history[RAVG_HIST_SIZE_MAX];
682 	u32 *curr_window_cpu, *prev_window_cpu;
683 	u32 curr_window, prev_window;
684 	u16 active_windows;
685 	u16 demand_scaled;
686 };
687 #else
sched_exit(struct task_struct * p)688 static inline void sched_exit(struct task_struct *p) { }
free_task_load_ptrs(struct task_struct * p)689 static inline void free_task_load_ptrs(struct task_struct *p) { }
690 #endif /* CONFIG_SCHED_WALT */
691 
692 struct sched_rt_entity {
693 	struct list_head		run_list;
694 	unsigned long			timeout;
695 	unsigned long			watchdog_stamp;
696 	unsigned int			time_slice;
697 	unsigned short			on_rq;
698 	unsigned short			on_list;
699 
700 	struct sched_rt_entity		*back;
701 #ifdef CONFIG_RT_GROUP_SCHED
702 	struct sched_rt_entity		*parent;
703 	/* rq on which this entity is (to be) queued: */
704 	struct rt_rq			*rt_rq;
705 	/* rq "owned" by this entity/group: */
706 	struct rt_rq			*my_q;
707 #endif
708 } __randomize_layout;
709 
710 struct sched_dl_entity {
711 	struct rb_node			rb_node;
712 
713 	/*
714 	 * Original scheduling parameters. Copied here from sched_attr
715 	 * during sched_setattr(), they will remain the same until
716 	 * the next sched_setattr().
717 	 */
718 	u64				dl_runtime;	/* Maximum runtime for each instance	*/
719 	u64				dl_deadline;	/* Relative deadline of each instance	*/
720 	u64				dl_period;	/* Separation of two instances (period) */
721 	u64				dl_bw;		/* dl_runtime / dl_period		*/
722 	u64				dl_density;	/* dl_runtime / dl_deadline		*/
723 
724 	/*
725 	 * Actual scheduling parameters. Initialized with the values above,
726 	 * they are continuously updated during task execution. Note that
727 	 * the remaining runtime could be < 0 in case we are in overrun.
728 	 */
729 	s64				runtime;	/* Remaining runtime for this instance	*/
730 	u64				deadline;	/* Absolute deadline for this instance	*/
731 	unsigned int			flags;		/* Specifying the scheduler behaviour	*/
732 
733 	/*
734 	 * Some bool flags:
735 	 *
736 	 * @dl_throttled tells if we exhausted the runtime. If so, the
737 	 * task has to wait for a replenishment to be performed at the
738 	 * next firing of dl_timer.
739 	 *
740 	 * @dl_yielded tells if task gave up the CPU before consuming
741 	 * all its available runtime during the last job.
742 	 *
743 	 * @dl_non_contending tells if the task is inactive while still
744 	 * contributing to the active utilization. In other words, it
745 	 * indicates if the inactive timer has been armed and its handler
746 	 * has not been executed yet. This flag is useful to avoid race
747 	 * conditions between the inactive timer handler and the wakeup
748 	 * code.
749 	 *
750 	 * @dl_overrun tells if the task asked to be informed about runtime
751 	 * overruns.
752 	 */
753 	unsigned int			dl_throttled      : 1;
754 	unsigned int			dl_yielded        : 1;
755 	unsigned int			dl_non_contending : 1;
756 	unsigned int			dl_overrun	  : 1;
757 
758 	/*
759 	 * Bandwidth enforcement timer. Each -deadline task has its
760 	 * own bandwidth to be enforced, thus we need one timer per task.
761 	 */
762 	struct hrtimer			dl_timer;
763 
764 	/*
765 	 * Inactive timer, responsible for decreasing the active utilization
766 	 * at the "0-lag time". When a -deadline task blocks, it contributes
767 	 * to GRUB's active utilization until the "0-lag time", hence a
768 	 * timer is needed to decrease the active utilization at the correct
769 	 * time.
770 	 */
771 	struct hrtimer inactive_timer;
772 
773 #ifdef CONFIG_RT_MUTEXES
774 	/*
775 	 * Priority Inheritance. When a DEADLINE scheduling entity is boosted
776 	 * pi_se points to the donor, otherwise points to the dl_se it belongs
777 	 * to (the original one/itself).
778 	 */
779 	struct sched_dl_entity *pi_se;
780 #endif
781 };
782 
783 #ifdef CONFIG_UCLAMP_TASK
784 /* Number of utilization clamp buckets (shorter alias) */
785 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT
786 
787 /*
788  * Utilization clamp for a scheduling entity
789  * @value:		clamp value "assigned" to a se
790  * @bucket_id:		bucket index corresponding to the "assigned" value
791  * @active:		the se is currently refcounted in a rq's bucket
792  * @user_defined:	the requested clamp value comes from user-space
793  *
794  * The bucket_id is the index of the clamp bucket matching the clamp value
795  * which is pre-computed and stored to avoid expensive integer divisions from
796  * the fast path.
797  *
798  * The active bit is set whenever a task has got an "effective" value assigned,
799  * which can be different from the clamp value "requested" from user-space.
800  * This allows to know a task is refcounted in the rq's bucket corresponding
801  * to the "effective" bucket_id.
802  *
803  * The user_defined bit is set whenever a task has got a task-specific clamp
804  * value requested from userspace, i.e. the system defaults apply to this task
805  * just as a restriction. This allows to relax default clamps when a less
806  * restrictive task-specific value has been requested, thus allowing to
807  * implement a "nice" semantic. For example, a task running with a 20%
808  * default boost can still drop its own boosting to 0%.
809  */
810 struct uclamp_se {
811 	unsigned int value		: bits_per(SCHED_CAPACITY_SCALE);
812 	unsigned int bucket_id		: bits_per(UCLAMP_BUCKETS);
813 	unsigned int active		: 1;
814 	unsigned int user_defined	: 1;
815 };
816 #endif /* CONFIG_UCLAMP_TASK */
817 
818 union rcu_special {
819 	struct {
820 		u8			blocked;
821 		u8			need_qs;
822 		u8			exp_hint; /* Hint for performance. */
823 		u8			need_mb; /* Readers need smp_mb(). */
824 	} b; /* Bits. */
825 	u32 s; /* Set of bits. */
826 };
827 
828 enum perf_event_task_context {
829 	perf_invalid_context = -1,
830 	perf_hw_context = 0,
831 	perf_sw_context,
832 	perf_nr_task_contexts,
833 };
834 
835 struct wake_q_node {
836 	struct wake_q_node *next;
837 };
838 
839 struct kmap_ctrl {
840 #ifdef CONFIG_KMAP_LOCAL
841 	int				idx;
842 	pte_t				pteval[KM_MAX_IDX];
843 #endif
844 };
845 
846 struct task_struct {
847 #ifdef CONFIG_THREAD_INFO_IN_TASK
848 	/*
849 	 * For reasons of header soup (see current_thread_info()), this
850 	 * must be the first element of task_struct.
851 	 */
852 	struct thread_info		thread_info;
853 #endif
854 	unsigned int			__state;
855 
856 #ifdef CONFIG_PREEMPT_RT
857 	/* saved state for "spinlock sleepers" */
858 	unsigned int			saved_state;
859 #endif
860 
861 	/*
862 	 * This begins the randomizable portion of task_struct. Only
863 	 * scheduling-critical items should be added above here.
864 	 */
865 	randomized_struct_fields_start
866 
867 	void				*stack;
868 	refcount_t			usage;
869 	/* Per task flags (PF_*), defined further below: */
870 	unsigned int			flags;
871 	unsigned int			ptrace;
872 
873 #ifdef CONFIG_SMP
874 	int				on_cpu;
875 	struct __call_single_node	wake_entry;
876 	unsigned int			wakee_flips;
877 	unsigned long			wakee_flip_decay_ts;
878 	struct task_struct		*last_wakee;
879 
880 	/*
881 	 * recent_used_cpu is initially set as the last CPU used by a task
882 	 * that wakes affine another task. Waker/wakee relationships can
883 	 * push tasks around a CPU where each wakeup moves to the next one.
884 	 * Tracking a recently used CPU allows a quick search for a recently
885 	 * used CPU that may be idle.
886 	 */
887 	int				recent_used_cpu;
888 	int				wake_cpu;
889 #endif
890 	int				on_rq;
891 
892 	int				prio;
893 	int				static_prio;
894 	int				normal_prio;
895 	unsigned int			rt_priority;
896 #ifdef CONFIG_SCHED_LATENCY_NICE
897 	int				latency_prio;
898 #endif
899 
900 	struct sched_entity		se;
901 	struct sched_rt_entity		rt;
902 #ifdef CONFIG_SCHED_WALT
903 	struct ravg ravg;
904 	/*
905 	 * 'init_load_pct' represents the initial task load assigned to children
906 	 * of this task
907 	 */
908 	u32 init_load_pct;
909 	u64 last_sleep_ts;
910 #endif
911 	struct sched_dl_entity		dl;
912 	const struct sched_class	*sched_class;
913 
914 #ifdef CONFIG_SCHED_CORE
915 	struct rb_node			core_node;
916 	unsigned long			core_cookie;
917 	unsigned int			core_occupation;
918 #endif
919 
920 #ifdef CONFIG_SCHED_RTG
921 	int rtg_depth;
922 	struct related_thread_group	*grp;
923 	struct list_head		grp_list;
924 #endif
925 
926 #ifdef CONFIG_CGROUP_SCHED
927 	struct task_group		*sched_task_group;
928 #endif
929 
930 #ifdef CONFIG_UCLAMP_TASK
931 	/*
932 	 * Clamp values requested for a scheduling entity.
933 	 * Must be updated with task_rq_lock() held.
934 	 */
935 	struct uclamp_se		uclamp_req[UCLAMP_CNT];
936 	/*
937 	 * Effective clamp values used for a scheduling entity.
938 	 * Must be updated with task_rq_lock() held.
939 	 */
940 	struct uclamp_se		uclamp[UCLAMP_CNT];
941 #endif
942 
943 	struct sched_statistics         stats;
944 
945 #ifdef CONFIG_PREEMPT_NOTIFIERS
946 	/* List of struct preempt_notifier: */
947 	struct hlist_head		preempt_notifiers;
948 #endif
949 
950 #ifdef CONFIG_BLK_DEV_IO_TRACE
951 	unsigned int			btrace_seq;
952 #endif
953 
954 	unsigned int			policy;
955 	int				nr_cpus_allowed;
956 	const cpumask_t			*cpus_ptr;
957 	cpumask_t			*user_cpus_ptr;
958 	cpumask_t			cpus_mask;
959 	void				*migration_pending;
960 #ifdef CONFIG_SMP
961 	unsigned short			migration_disabled;
962 #endif
963 	unsigned short			migration_flags;
964 
965 #ifdef CONFIG_PREEMPT_RCU
966 	int				rcu_read_lock_nesting;
967 	union rcu_special		rcu_read_unlock_special;
968 	struct list_head		rcu_node_entry;
969 	struct rcu_node			*rcu_blocked_node;
970 #endif /* #ifdef CONFIG_PREEMPT_RCU */
971 
972 #ifdef CONFIG_TASKS_RCU
973 	unsigned long			rcu_tasks_nvcsw;
974 	u8				rcu_tasks_holdout;
975 	u8				rcu_tasks_idx;
976 	int				rcu_tasks_idle_cpu;
977 	struct list_head		rcu_tasks_holdout_list;
978 	int				rcu_tasks_exit_cpu;
979 	struct list_head		rcu_tasks_exit_list;
980 #endif /* #ifdef CONFIG_TASKS_RCU */
981 
982 #ifdef CONFIG_TASKS_TRACE_RCU
983 	int				trc_reader_nesting;
984 	int				trc_ipi_to_cpu;
985 	union rcu_special		trc_reader_special;
986 	struct list_head		trc_holdout_list;
987 	struct list_head		trc_blkd_node;
988 	int				trc_blkd_cpu;
989 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
990 
991 	struct sched_info		sched_info;
992 
993 	struct list_head		tasks;
994 #ifdef CONFIG_SMP
995 	struct plist_node		pushable_tasks;
996 	struct rb_node			pushable_dl_tasks;
997 #endif
998 
999 	struct mm_struct		*mm;
1000 	struct mm_struct		*active_mm;
1001 
1002 	int				exit_state;
1003 	int				exit_code;
1004 	int				exit_signal;
1005 	/* The signal sent when the parent dies: */
1006 	int				pdeath_signal;
1007 	/* JOBCTL_*, siglock protected: */
1008 	unsigned long			jobctl;
1009 
1010 	/* Used for emulating ABI behavior of previous Linux versions: */
1011 	unsigned int			personality;
1012 
1013 	/* Scheduler bits, serialized by scheduler locks: */
1014 	unsigned			sched_reset_on_fork:1;
1015 	unsigned			sched_contributes_to_load:1;
1016 	unsigned			sched_migrated:1;
1017 	unsigned			sched_task_hot:1;
1018 
1019 	/* Force alignment to the next boundary: */
1020 	unsigned			:0;
1021 
1022 	/* Unserialized, strictly 'current' */
1023 
1024 	/*
1025 	 * This field must not be in the scheduler word above due to wakelist
1026 	 * queueing no longer being serialized by p->on_cpu. However:
1027 	 *
1028 	 * p->XXX = X;			ttwu()
1029 	 * schedule()			  if (p->on_rq && ..) // false
1030 	 *   smp_mb__after_spinlock();	  if (smp_load_acquire(&p->on_cpu) && //true
1031 	 *   deactivate_task()		      ttwu_queue_wakelist())
1032 	 *     p->on_rq = 0;			p->sched_remote_wakeup = Y;
1033 	 *
1034 	 * guarantees all stores of 'current' are visible before
1035 	 * ->sched_remote_wakeup gets used, so it can be in this word.
1036 	 */
1037 	unsigned			sched_remote_wakeup:1;
1038 
1039 	/* Bit to tell LSMs we're in execve(): */
1040 	unsigned			in_execve:1;
1041 	unsigned			in_iowait:1;
1042 #ifndef TIF_RESTORE_SIGMASK
1043 	unsigned			restore_sigmask:1;
1044 #endif
1045 #ifdef CONFIG_MEMCG
1046 	unsigned			in_user_fault:1;
1047 #endif
1048 #ifdef CONFIG_LRU_GEN
1049 	/* whether the LRU algorithm may apply to this access */
1050 	unsigned			in_lru_fault:1;
1051 #endif
1052 #ifdef CONFIG_COMPAT_BRK
1053 	unsigned			brk_randomized:1;
1054 #endif
1055 #ifdef CONFIG_CGROUPS
1056 	/* disallow userland-initiated cgroup migration */
1057 	unsigned			no_cgroup_migration:1;
1058 	/* task is frozen/stopped (used by the cgroup freezer) */
1059 	unsigned			frozen:1;
1060 #endif
1061 #ifdef CONFIG_BLK_CGROUP
1062 	unsigned			use_memdelay:1;
1063 #endif
1064 #ifdef CONFIG_PSI
1065 	/* Stalled due to lack of memory */
1066 	unsigned			in_memstall:1;
1067 #endif
1068 #ifdef CONFIG_PAGE_OWNER
1069 	/* Used by page_owner=on to detect recursion in page tracking. */
1070 	unsigned			in_page_owner:1;
1071 #endif
1072 #ifdef CONFIG_EVENTFD
1073 	/* Recursion prevention for eventfd_signal() */
1074 	unsigned			in_eventfd:1;
1075 #endif
1076 #ifdef CONFIG_IOMMU_SVA
1077 	unsigned			pasid_activated:1;
1078 #endif
1079 #ifdef	CONFIG_CPU_SUP_INTEL
1080 	unsigned			reported_split_lock:1;
1081 #endif
1082 #ifdef CONFIG_TASK_DELAY_ACCT
1083 	/* delay due to memory thrashing */
1084 	unsigned                        in_thrashing:1;
1085 #endif
1086 
1087 	unsigned long			atomic_flags; /* Flags requiring atomic access. */
1088 
1089 	struct restart_block		restart_block;
1090 
1091 	pid_t				pid;
1092 	pid_t				tgid;
1093 
1094 #ifdef CONFIG_STACKPROTECTOR
1095 	/* Canary value for the -fstack-protector GCC feature: */
1096 	unsigned long			stack_canary;
1097 #endif
1098 	/*
1099 	 * Pointers to the (original) parent process, youngest child, younger sibling,
1100 	 * older sibling, respectively.  (p->father can be replaced with
1101 	 * p->real_parent->pid)
1102 	 */
1103 
1104 	/* Real parent process: */
1105 	struct task_struct __rcu	*real_parent;
1106 
1107 	/* Recipient of SIGCHLD, wait4() reports: */
1108 	struct task_struct __rcu	*parent;
1109 
1110 	/*
1111 	 * Children/sibling form the list of natural children:
1112 	 */
1113 	struct list_head		children;
1114 	struct list_head		sibling;
1115 	struct task_struct		*group_leader;
1116 
1117 	/*
1118 	 * 'ptraced' is the list of tasks this task is using ptrace() on.
1119 	 *
1120 	 * This includes both natural children and PTRACE_ATTACH targets.
1121 	 * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
1122 	 */
1123 	struct list_head		ptraced;
1124 	struct list_head		ptrace_entry;
1125 
1126 	/* PID/PID hash table linkage. */
1127 	struct pid			*thread_pid;
1128 	struct hlist_node		pid_links[PIDTYPE_MAX];
1129 	struct list_head		thread_group;
1130 	struct list_head		thread_node;
1131 
1132 	struct completion		*vfork_done;
1133 
1134 	/* CLONE_CHILD_SETTID: */
1135 	int __user			*set_child_tid;
1136 
1137 	/* CLONE_CHILD_CLEARTID: */
1138 	int __user			*clear_child_tid;
1139 
1140 	/* PF_KTHREAD | PF_IO_WORKER */
1141 	void				*worker_private;
1142 
1143 	u64				utime;
1144 	u64				stime;
1145 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
1146 	u64				utimescaled;
1147 	u64				stimescaled;
1148 #endif
1149 	u64				gtime;
1150 	struct prev_cputime		prev_cputime;
1151 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1152 	struct vtime			vtime;
1153 #endif
1154 
1155 #ifdef CONFIG_NO_HZ_FULL
1156 	atomic_t			tick_dep_mask;
1157 #endif
1158 	/* Context switch counts: */
1159 	unsigned long			nvcsw;
1160 	unsigned long			nivcsw;
1161 
1162 	/* Monotonic time in nsecs: */
1163 	u64				start_time;
1164 
1165 	/* Boot based time in nsecs: */
1166 	u64				start_boottime;
1167 
1168 	/* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
1169 	unsigned long			min_flt;
1170 	unsigned long			maj_flt;
1171 
1172 	/* Empty if CONFIG_POSIX_CPUTIMERS=n */
1173 	struct posix_cputimers		posix_cputimers;
1174 
1175 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK
1176 	struct posix_cputimers_work	posix_cputimers_work;
1177 #endif
1178 
1179 	/* Process credentials: */
1180 
1181 	/* Tracer's credentials at attach: */
1182 	const struct cred __rcu		*ptracer_cred;
1183 
1184 	/* Objective and real subjective task credentials (COW): */
1185 	const struct cred __rcu		*real_cred;
1186 
1187 	/* Effective (overridable) subjective task credentials (COW): */
1188 	const struct cred __rcu		*cred;
1189 
1190 #ifdef CONFIG_KEYS
1191 	/* Cached requested key. */
1192 	struct key			*cached_requested_key;
1193 #endif
1194 
1195 	/*
1196 	 * executable name, excluding path.
1197 	 *
1198 	 * - normally initialized setup_new_exec()
1199 	 * - access it with [gs]et_task_comm()
1200 	 * - lock it with task_lock()
1201 	 */
1202 	char				comm[TASK_COMM_LEN];
1203 
1204 	struct nameidata		*nameidata;
1205 
1206 #ifdef CONFIG_SYSVIPC
1207 	struct sysv_sem			sysvsem;
1208 	struct sysv_shm			sysvshm;
1209 #endif
1210 #ifdef CONFIG_DETECT_HUNG_TASK
1211 	unsigned long			last_switch_count;
1212 	unsigned long			last_switch_time;
1213 #endif
1214 	/* Filesystem information: */
1215 	struct fs_struct		*fs;
1216 
1217 	/* Open file information: */
1218 	struct files_struct		*files;
1219 
1220 #ifdef CONFIG_IO_URING
1221 	struct io_uring_task		*io_uring;
1222 #endif
1223 
1224 	/* Namespaces: */
1225 	struct nsproxy			*nsproxy;
1226 
1227 	/* Signal handlers: */
1228 	struct signal_struct		*signal;
1229 	struct sighand_struct __rcu		*sighand;
1230 	sigset_t			blocked;
1231 	sigset_t			real_blocked;
1232 	/* Restored if set_restore_sigmask() was used: */
1233 	sigset_t			saved_sigmask;
1234 	struct sigpending		pending;
1235 	unsigned long			sas_ss_sp;
1236 	size_t				sas_ss_size;
1237 	unsigned int			sas_ss_flags;
1238 
1239 	struct callback_head		*task_works;
1240 
1241 #ifdef CONFIG_AUDIT
1242 #ifdef CONFIG_AUDITSYSCALL
1243 	struct audit_context		*audit_context;
1244 #endif
1245 	kuid_t				loginuid;
1246 	unsigned int			sessionid;
1247 #endif
1248 	struct seccomp			seccomp;
1249 	struct syscall_user_dispatch	syscall_dispatch;
1250 
1251 	/* Thread group tracking: */
1252 	u64				parent_exec_id;
1253 	u64				self_exec_id;
1254 
1255 	/* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
1256 	spinlock_t			alloc_lock;
1257 
1258 	/* Protection of the PI data structures: */
1259 	raw_spinlock_t			pi_lock;
1260 
1261 	struct wake_q_node		wake_q;
1262 
1263 #ifdef CONFIG_RT_MUTEXES
1264 	/* PI waiters blocked on a rt_mutex held by this task: */
1265 	struct rb_root_cached		pi_waiters;
1266 	/* Updated under owner's pi_lock and rq lock */
1267 	struct task_struct		*pi_top_task;
1268 	/* Deadlock detection and priority inheritance handling: */
1269 	struct rt_mutex_waiter		*pi_blocked_on;
1270 #endif
1271 
1272 #ifdef CONFIG_DEBUG_MUTEXES
1273 	/* Mutex deadlock detection: */
1274 	struct mutex_waiter		*blocked_on;
1275 #endif
1276 
1277 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1278 	int				non_block_count;
1279 #endif
1280 
1281 #ifdef CONFIG_TRACE_IRQFLAGS
1282 	struct irqtrace_events		irqtrace;
1283 	unsigned int			hardirq_threaded;
1284 	u64				hardirq_chain_key;
1285 	int				softirqs_enabled;
1286 	int				softirq_context;
1287 	int				irq_config;
1288 #endif
1289 #ifdef CONFIG_PREEMPT_RT
1290 	int				softirq_disable_cnt;
1291 #endif
1292 
1293 #ifdef CONFIG_LOCKDEP
1294 # define MAX_LOCK_DEPTH			48UL
1295 	u64				curr_chain_key;
1296 	int				lockdep_depth;
1297 	unsigned int			lockdep_recursion;
1298 	struct held_lock		held_locks[MAX_LOCK_DEPTH];
1299 #endif
1300 
1301 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP)
1302 	unsigned int			in_ubsan;
1303 #endif
1304 
1305 	/* Journalling filesystem info: */
1306 	void				*journal_info;
1307 
1308 	/* Stacked block device info: */
1309 	struct bio_list			*bio_list;
1310 
1311 	/* Stack plugging: */
1312 	struct blk_plug			*plug;
1313 
1314 	/* VM state: */
1315 	struct reclaim_state		*reclaim_state;
1316 
1317 	struct io_context		*io_context;
1318 
1319 #ifdef CONFIG_COMPACTION
1320 	struct capture_control		*capture_control;
1321 #endif
1322 	/* Ptrace state: */
1323 	unsigned long			ptrace_message;
1324 	kernel_siginfo_t		*last_siginfo;
1325 
1326 	struct task_io_accounting	ioac;
1327 #ifdef CONFIG_PSI
1328 	/* Pressure stall state */
1329 	unsigned int			psi_flags;
1330 #endif
1331 #ifdef CONFIG_TASK_XACCT
1332 	/* Accumulated RSS usage: */
1333 	u64				acct_rss_mem1;
1334 	/* Accumulated virtual memory usage: */
1335 	u64				acct_vm_mem1;
1336 	/* stime + utime since last update: */
1337 	u64				acct_timexpd;
1338 #endif
1339 #ifdef CONFIG_CPUSETS
1340 	/* Protected by ->alloc_lock: */
1341 	nodemask_t			mems_allowed;
1342 	/* Sequence number to catch updates: */
1343 	seqcount_spinlock_t		mems_allowed_seq;
1344 	int				cpuset_mem_spread_rotor;
1345 	int				cpuset_slab_spread_rotor;
1346 #endif
1347 #ifdef CONFIG_CGROUPS
1348 	/* Control Group info protected by css_set_lock: */
1349 	struct css_set __rcu		*cgroups;
1350 	/* cg_list protected by css_set_lock and tsk->alloc_lock: */
1351 	struct list_head		cg_list;
1352 #endif
1353 #ifdef CONFIG_X86_CPU_RESCTRL
1354 	u32				closid;
1355 	u32				rmid;
1356 #endif
1357 #ifdef CONFIG_FUTEX
1358 	struct robust_list_head __user	*robust_list;
1359 #ifdef CONFIG_COMPAT
1360 	struct compat_robust_list_head __user *compat_robust_list;
1361 #endif
1362 	struct list_head		pi_state_list;
1363 	struct futex_pi_state		*pi_state_cache;
1364 	struct mutex			futex_exit_mutex;
1365 	unsigned int			futex_state;
1366 #endif
1367 #ifdef CONFIG_PERF_EVENTS
1368 	struct perf_event_context	*perf_event_ctxp;
1369 	struct mutex			perf_event_mutex;
1370 	struct list_head		perf_event_list;
1371 #endif
1372 #ifdef CONFIG_DEBUG_PREEMPT
1373 	unsigned long			preempt_disable_ip;
1374 #endif
1375 #ifdef CONFIG_NUMA
1376 	/* Protected by alloc_lock: */
1377 	struct mempolicy		*mempolicy;
1378 	short				il_prev;
1379 	short				pref_node_fork;
1380 #endif
1381 #ifdef CONFIG_NUMA_BALANCING
1382 	int				numa_scan_seq;
1383 	unsigned int			numa_scan_period;
1384 	unsigned int			numa_scan_period_max;
1385 	int				numa_preferred_nid;
1386 	unsigned long			numa_migrate_retry;
1387 	/* Migration stamp: */
1388 	u64				node_stamp;
1389 	u64				last_task_numa_placement;
1390 	u64				last_sum_exec_runtime;
1391 	struct callback_head		numa_work;
1392 
1393 	/*
1394 	 * This pointer is only modified for current in syscall and
1395 	 * pagefault context (and for tasks being destroyed), so it can be read
1396 	 * from any of the following contexts:
1397 	 *  - RCU read-side critical section
1398 	 *  - current->numa_group from everywhere
1399 	 *  - task's runqueue locked, task not running
1400 	 */
1401 	struct numa_group __rcu		*numa_group;
1402 
1403 	/*
1404 	 * numa_faults is an array split into four regions:
1405 	 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1406 	 * in this precise order.
1407 	 *
1408 	 * faults_memory: Exponential decaying average of faults on a per-node
1409 	 * basis. Scheduling placement decisions are made based on these
1410 	 * counts. The values remain static for the duration of a PTE scan.
1411 	 * faults_cpu: Track the nodes the process was running on when a NUMA
1412 	 * hinting fault was incurred.
1413 	 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1414 	 * during the current scan window. When the scan completes, the counts
1415 	 * in faults_memory and faults_cpu decay and these values are copied.
1416 	 */
1417 	unsigned long			*numa_faults;
1418 	unsigned long			total_numa_faults;
1419 
1420 	/*
1421 	 * numa_faults_locality tracks if faults recorded during the last
1422 	 * scan window were remote/local or failed to migrate. The task scan
1423 	 * period is adapted based on the locality of the faults with different
1424 	 * weights depending on whether they were shared or private faults
1425 	 */
1426 	unsigned long			numa_faults_locality[3];
1427 
1428 	unsigned long			numa_pages_migrated;
1429 #endif /* CONFIG_NUMA_BALANCING */
1430 
1431 #ifdef CONFIG_RSEQ
1432 	struct rseq __user *rseq;
1433 	u32 rseq_len;
1434 	u32 rseq_sig;
1435 	/*
1436 	 * RmW on rseq_event_mask must be performed atomically
1437 	 * with respect to preemption.
1438 	 */
1439 	unsigned long rseq_event_mask;
1440 #endif
1441 
1442 #ifdef CONFIG_SCHED_MM_CID
1443 	int				mm_cid;		/* Current cid in mm */
1444 	int				last_mm_cid;	/* Most recent cid in mm */
1445 	int				migrate_from_cpu;
1446 	int				mm_cid_active;	/* Whether cid bitmap is active */
1447 	struct callback_head		cid_work;
1448 #endif
1449 
1450 	struct tlbflush_unmap_batch	tlb_ubc;
1451 
1452 	/* Cache last used pipe for splice(): */
1453 	struct pipe_inode_info		*splice_pipe;
1454 
1455 	struct page_frag		task_frag;
1456 
1457 #ifdef CONFIG_TASK_DELAY_ACCT
1458 	struct task_delay_info		*delays;
1459 #endif
1460 
1461 #ifdef CONFIG_FAULT_INJECTION
1462 	int				make_it_fail;
1463 	unsigned int			fail_nth;
1464 #endif
1465 	/*
1466 	 * When (nr_dirtied >= nr_dirtied_pause), it's time to call
1467 	 * balance_dirty_pages() for a dirty throttling pause:
1468 	 */
1469 	int				nr_dirtied;
1470 	int				nr_dirtied_pause;
1471 	/* Start of a write-and-pause period: */
1472 	unsigned long			dirty_paused_when;
1473 
1474 #ifdef CONFIG_LATENCYTOP
1475 	int				latency_record_count;
1476 	struct latency_record		latency_record[LT_SAVECOUNT];
1477 #endif
1478 	/*
1479 	 * Time slack values; these are used to round up poll() and
1480 	 * select() etc timeout values. These are in nanoseconds.
1481 	 */
1482 	u64				timer_slack_ns;
1483 	u64				default_timer_slack_ns;
1484 
1485 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
1486 	unsigned int			kasan_depth;
1487 #endif
1488 
1489 #ifdef CONFIG_KCSAN
1490 	struct kcsan_ctx		kcsan_ctx;
1491 #ifdef CONFIG_TRACE_IRQFLAGS
1492 	struct irqtrace_events		kcsan_save_irqtrace;
1493 #endif
1494 #ifdef CONFIG_KCSAN_WEAK_MEMORY
1495 	int				kcsan_stack_depth;
1496 #endif
1497 #endif
1498 
1499 #ifdef CONFIG_KMSAN
1500 	struct kmsan_ctx		kmsan_ctx;
1501 #endif
1502 
1503 #if IS_ENABLED(CONFIG_KUNIT)
1504 	struct kunit			*kunit_test;
1505 #endif
1506 
1507 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1508 	/* Index of current stored address in ret_stack: */
1509 	int				curr_ret_stack;
1510 	int				curr_ret_depth;
1511 
1512 	/* Stack of return addresses for return function tracing: */
1513 	struct ftrace_ret_stack		*ret_stack;
1514 
1515 	/* Timestamp for last schedule: */
1516 	unsigned long long		ftrace_timestamp;
1517 
1518 	/*
1519 	 * Number of functions that haven't been traced
1520 	 * because of depth overrun:
1521 	 */
1522 	atomic_t			trace_overrun;
1523 
1524 	/* Pause tracing: */
1525 	atomic_t			tracing_graph_pause;
1526 #endif
1527 
1528 #ifdef CONFIG_TRACING
1529 	/* Bitmask and counter of trace recursion: */
1530 	unsigned long			trace_recursion;
1531 #endif /* CONFIG_TRACING */
1532 
1533 #ifdef CONFIG_KCOV
1534 	/* See kernel/kcov.c for more details. */
1535 
1536 	/* Coverage collection mode enabled for this task (0 if disabled): */
1537 	unsigned int			kcov_mode;
1538 
1539 	/* Size of the kcov_area: */
1540 	unsigned int			kcov_size;
1541 
1542 	/* Buffer for coverage collection: */
1543 	void				*kcov_area;
1544 
1545 	/* KCOV descriptor wired with this task or NULL: */
1546 	struct kcov			*kcov;
1547 
1548 	/* KCOV common handle for remote coverage collection: */
1549 	u64				kcov_handle;
1550 
1551 	/* KCOV sequence number: */
1552 	int				kcov_sequence;
1553 
1554 	/* Collect coverage from softirq context: */
1555 	unsigned int			kcov_softirq;
1556 #endif
1557 
1558 #ifdef CONFIG_MEMCG
1559 	struct mem_cgroup		*memcg_in_oom;
1560 	gfp_t				memcg_oom_gfp_mask;
1561 	int				memcg_oom_order;
1562 
1563 	/* Number of pages to reclaim on returning to userland: */
1564 	unsigned int			memcg_nr_pages_over_high;
1565 
1566 	/* Used by memcontrol for targeted memcg charge: */
1567 	struct mem_cgroup		*active_memcg;
1568 #endif
1569 
1570 #ifdef CONFIG_BLK_CGROUP
1571 	struct gendisk			*throttle_disk;
1572 #endif
1573 
1574 #ifdef CONFIG_UPROBES
1575 	struct uprobe_task		*utask;
1576 #endif
1577 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1578 	unsigned int			sequential_io;
1579 	unsigned int			sequential_io_avg;
1580 #endif
1581 	struct kmap_ctrl		kmap_ctrl;
1582 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1583 	unsigned long			task_state_change;
1584 # ifdef CONFIG_PREEMPT_RT
1585 	unsigned long			saved_state_change;
1586 # endif
1587 #endif
1588 	struct rcu_head			rcu;
1589 	refcount_t			rcu_users;
1590 	int				pagefault_disabled;
1591 #ifdef CONFIG_MMU
1592 	struct task_struct		*oom_reaper_list;
1593 	struct timer_list		oom_reaper_timer;
1594 #endif
1595 #ifdef CONFIG_VMAP_STACK
1596 	struct vm_struct		*stack_vm_area;
1597 #endif
1598 #ifdef CONFIG_THREAD_INFO_IN_TASK
1599 	/* A live task holds one reference: */
1600 	refcount_t			stack_refcount;
1601 #endif
1602 #ifdef CONFIG_LIVEPATCH
1603 	int patch_state;
1604 #endif
1605 #ifdef CONFIG_SECURITY
1606 	/* Used by LSM modules for access restriction: */
1607 	void				*security;
1608 #endif
1609 #ifdef CONFIG_BPF_SYSCALL
1610 	/* Used by BPF task local storage */
1611 	struct bpf_local_storage __rcu	*bpf_storage;
1612 	/* Used for BPF run context */
1613 	struct bpf_run_ctx		*bpf_ctx;
1614 #endif
1615 
1616 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK
1617 	unsigned long			lowest_stack;
1618 	unsigned long			prev_lowest_stack;
1619 #endif
1620 
1621 #ifdef CONFIG_X86_MCE
1622 	void __user			*mce_vaddr;
1623 	__u64				mce_kflags;
1624 	u64				mce_addr;
1625 	__u64				mce_ripv : 1,
1626 					mce_whole_page : 1,
1627 					__mce_reserved : 62;
1628 	struct callback_head		mce_kill_me;
1629 	int				mce_count;
1630 #endif
1631 
1632 #ifdef CONFIG_KRETPROBES
1633 	struct llist_head               kretprobe_instances;
1634 #endif
1635 #ifdef CONFIG_RETHOOK
1636 	struct llist_head               rethooks;
1637 #endif
1638 
1639 #ifdef CONFIG_ARCH_HAS_PARANOID_L1D_FLUSH
1640 	/*
1641 	 * If L1D flush is supported on mm context switch
1642 	 * then we use this callback head to queue kill work
1643 	 * to kill tasks that are not running on SMT disabled
1644 	 * cores
1645 	 */
1646 	struct callback_head		l1d_flush_kill;
1647 #endif
1648 
1649 #ifdef CONFIG_RV
1650 	/*
1651 	 * Per-task RV monitor. Nowadays fixed in RV_PER_TASK_MONITORS.
1652 	 * If we find justification for more monitors, we can think
1653 	 * about adding more or developing a dynamic method. So far,
1654 	 * none of these are justified.
1655 	 */
1656 	union rv_task_monitor		rv[RV_PER_TASK_MONITORS];
1657 #endif
1658 
1659 #ifdef CONFIG_USER_EVENTS
1660 	struct user_event_mm		*user_event_mm;
1661 #endif
1662 
1663 #ifdef CONFIG_ACCESS_TOKENID
1664 	u64				token;
1665 	u64				ftoken;
1666 #endif
1667 
1668 	/*
1669 	 * New fields for task_struct should be added above here, so that
1670 	 * they are included in the randomized portion of task_struct.
1671 	 */
1672 	randomized_struct_fields_end
1673 
1674 	/* CPU-specific state of this task: */
1675 	struct thread_struct		thread;
1676 
1677 	/*
1678 	 * WARNING: on x86, 'thread_struct' contains a variable-sized
1679 	 * structure.  It *MUST* be at the end of 'task_struct'.
1680 	 *
1681 	 * Do not put anything below here!
1682 	 */
1683 };
1684 
task_pid(struct task_struct * task)1685 static inline struct pid *task_pid(struct task_struct *task)
1686 {
1687 	return task->thread_pid;
1688 }
1689 
1690 /*
1691  * the helpers to get the task's different pids as they are seen
1692  * from various namespaces
1693  *
1694  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1695  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1696  *                     current.
1697  * task_xid_nr_ns()  : id seen from the ns specified;
1698  *
1699  * see also pid_nr() etc in include/linux/pid.h
1700  */
1701 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns);
1702 
task_pid_nr(struct task_struct * tsk)1703 static inline pid_t task_pid_nr(struct task_struct *tsk)
1704 {
1705 	return tsk->pid;
1706 }
1707 
task_pid_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1708 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1709 {
1710 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1711 }
1712 
task_pid_vnr(struct task_struct * tsk)1713 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1714 {
1715 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1716 }
1717 
1718 
task_tgid_nr(struct task_struct * tsk)1719 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1720 {
1721 	return tsk->tgid;
1722 }
1723 
1724 /**
1725  * pid_alive - check that a task structure is not stale
1726  * @p: Task structure to be checked.
1727  *
1728  * Test if a process is not yet dead (at most zombie state)
1729  * If pid_alive fails, then pointers within the task structure
1730  * can be stale and must not be dereferenced.
1731  *
1732  * Return: 1 if the process is alive. 0 otherwise.
1733  */
pid_alive(const struct task_struct * p)1734 static inline int pid_alive(const struct task_struct *p)
1735 {
1736 	return p->thread_pid != NULL;
1737 }
1738 
task_pgrp_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1739 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1740 {
1741 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1742 }
1743 
task_pgrp_vnr(struct task_struct * tsk)1744 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1745 {
1746 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1747 }
1748 
1749 
task_session_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1750 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1751 {
1752 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1753 }
1754 
task_session_vnr(struct task_struct * tsk)1755 static inline pid_t task_session_vnr(struct task_struct *tsk)
1756 {
1757 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1758 }
1759 
task_tgid_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1760 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1761 {
1762 	return __task_pid_nr_ns(tsk, PIDTYPE_TGID, ns);
1763 }
1764 
task_tgid_vnr(struct task_struct * tsk)1765 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1766 {
1767 	return __task_pid_nr_ns(tsk, PIDTYPE_TGID, NULL);
1768 }
1769 
task_ppid_nr_ns(const struct task_struct * tsk,struct pid_namespace * ns)1770 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1771 {
1772 	pid_t pid = 0;
1773 
1774 	rcu_read_lock();
1775 	if (pid_alive(tsk))
1776 		pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1777 	rcu_read_unlock();
1778 
1779 	return pid;
1780 }
1781 
task_ppid_nr(const struct task_struct * tsk)1782 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1783 {
1784 	return task_ppid_nr_ns(tsk, &init_pid_ns);
1785 }
1786 
1787 /* Obsolete, do not use: */
task_pgrp_nr(struct task_struct * tsk)1788 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1789 {
1790 	return task_pgrp_nr_ns(tsk, &init_pid_ns);
1791 }
1792 
1793 #define TASK_REPORT_IDLE	(TASK_REPORT + 1)
1794 #define TASK_REPORT_MAX		(TASK_REPORT_IDLE << 1)
1795 
__task_state_index(unsigned int tsk_state,unsigned int tsk_exit_state)1796 static inline unsigned int __task_state_index(unsigned int tsk_state,
1797 					      unsigned int tsk_exit_state)
1798 {
1799 	unsigned int state = (tsk_state | tsk_exit_state) & TASK_REPORT;
1800 
1801 	BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX);
1802 
1803 	if ((tsk_state & TASK_IDLE) == TASK_IDLE)
1804 		state = TASK_REPORT_IDLE;
1805 
1806 	/*
1807 	 * We're lying here, but rather than expose a completely new task state
1808 	 * to userspace, we can make this appear as if the task has gone through
1809 	 * a regular rt_mutex_lock() call.
1810 	 * Report frozen tasks as uninterruptible.
1811 	 */
1812 	if ((tsk_state & TASK_RTLOCK_WAIT) || (tsk_state & TASK_FROZEN))
1813 		state = TASK_UNINTERRUPTIBLE;
1814 
1815 	return fls(state);
1816 }
1817 
task_state_index(struct task_struct * tsk)1818 static inline unsigned int task_state_index(struct task_struct *tsk)
1819 {
1820 	return __task_state_index(READ_ONCE(tsk->__state), tsk->exit_state);
1821 }
1822 
task_index_to_char(unsigned int state)1823 static inline char task_index_to_char(unsigned int state)
1824 {
1825 	static const char state_char[] = "RSDTtXZPI";
1826 
1827 	BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1);
1828 
1829 	return state_char[state];
1830 }
1831 
task_state_to_char(struct task_struct * tsk)1832 static inline char task_state_to_char(struct task_struct *tsk)
1833 {
1834 	return task_index_to_char(task_state_index(tsk));
1835 }
1836 
1837 /**
1838  * is_global_init - check if a task structure is init. Since init
1839  * is free to have sub-threads we need to check tgid.
1840  * @tsk: Task structure to be checked.
1841  *
1842  * Check if a task structure is the first user space task the kernel created.
1843  *
1844  * Return: 1 if the task structure is init. 0 otherwise.
1845  */
is_global_init(struct task_struct * tsk)1846 static inline int is_global_init(struct task_struct *tsk)
1847 {
1848 	return task_tgid_nr(tsk) == 1;
1849 }
1850 
1851 extern struct pid *cad_pid;
1852 
1853 /*
1854  * Per process flags
1855  */
1856 #define PF_VCPU			0x00000001	/* I'm a virtual CPU */
1857 #define PF_IDLE			0x00000002	/* I am an IDLE thread */
1858 #define PF_EXITING		0x00000004	/* Getting shut down */
1859 #define PF_POSTCOREDUMP		0x00000008	/* Coredumps should ignore this task */
1860 #define PF_IO_WORKER		0x00000010	/* Task is an IO worker */
1861 #define PF_WQ_WORKER		0x00000020	/* I'm a workqueue worker */
1862 #define PF_FORKNOEXEC		0x00000040	/* Forked but didn't exec */
1863 #define PF_MCE_PROCESS		0x00000080      /* Process policy on mce errors */
1864 #define PF_SUPERPRIV		0x00000100	/* Used super-user privileges */
1865 #define PF_DUMPCORE		0x00000200	/* Dumped core */
1866 #define PF_SIGNALED		0x00000400	/* Killed by a signal */
1867 #define PF_MEMALLOC		0x00000800	/* Allocating memory */
1868 #define PF_NPROC_EXCEEDED	0x00001000	/* set_user() noticed that RLIMIT_NPROC was exceeded */
1869 #define PF_USED_MATH		0x00002000	/* If unset the fpu must be initialized before use */
1870 #define PF_USER_WORKER		0x00004000	/* Kernel thread cloned from userspace thread */
1871 #define PF_NOFREEZE		0x00008000	/* This thread should not be frozen */
1872 #define PF_KCOMPACTD		0x00010000	/* I am kcompactd */
1873 #define PF_KSWAPD		0x00020000	/* I am kswapd */
1874 #define PF_MEMALLOC_NOFS	0x00040000	/* All allocation requests will inherit GFP_NOFS */
1875 #define PF_MEMALLOC_NOIO	0x00080000	/* All allocation requests will inherit GFP_NOIO */
1876 #define PF_LOCAL_THROTTLE	0x00100000	/* Throttle writes only against the bdi I write to,
1877 						 * I am cleaning dirty pages from some other bdi. */
1878 #define PF_KTHREAD		0x00200000	/* I am a kernel thread */
1879 #define PF_RANDOMIZE		0x00400000	/* Randomize virtual address space */
1880 #define PF__HOLE__00800000	0x00800000
1881 #define PF_FROZEN		PF__HOLE__00800000	/* Frozen for system suspend */
1882 #define PF__HOLE__01000000	0x01000000
1883 #define PF__HOLE__02000000	0x02000000
1884 #define PF_NO_SETAFFINITY	0x04000000	/* Userland is not allowed to meddle with cpus_mask */
1885 #define PF_MCE_EARLY		0x08000000      /* Early kill for mce process policy */
1886 #define PF_MEMALLOC_PIN		0x10000000	/* Allocation context constrained to zones which allow long term pinning. */
1887 #define PF__HOLE__20000000	0x20000000
1888 #define PF__HOLE__40000000	0x40000000
1889 #define PF_SUSPEND_TASK		0x80000000      /* This thread called freeze_processes() and should not be frozen */
1890 
1891 /*
1892  * Only the _current_ task can read/write to tsk->flags, but other
1893  * tasks can access tsk->flags in readonly mode for example
1894  * with tsk_used_math (like during threaded core dumping).
1895  * There is however an exception to this rule during ptrace
1896  * or during fork: the ptracer task is allowed to write to the
1897  * child->flags of its traced child (same goes for fork, the parent
1898  * can write to the child->flags), because we're guaranteed the
1899  * child is not running and in turn not changing child->flags
1900  * at the same time the parent does it.
1901  */
1902 #define clear_stopped_child_used_math(child)	do { (child)->flags &= ~PF_USED_MATH; } while (0)
1903 #define set_stopped_child_used_math(child)	do { (child)->flags |= PF_USED_MATH; } while (0)
1904 #define clear_used_math()			clear_stopped_child_used_math(current)
1905 #define set_used_math()				set_stopped_child_used_math(current)
1906 
1907 #define conditional_stopped_child_used_math(condition, child) \
1908 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1909 
1910 #define conditional_used_math(condition)	conditional_stopped_child_used_math(condition, current)
1911 
1912 #define copy_to_stopped_child_used_math(child) \
1913 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1914 
1915 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1916 #define tsk_used_math(p)			((p)->flags & PF_USED_MATH)
1917 #define used_math()				tsk_used_math(current)
1918 
is_percpu_thread(void)1919 static __always_inline bool is_percpu_thread(void)
1920 {
1921 #ifdef CONFIG_SMP
1922 	return (current->flags & PF_NO_SETAFFINITY) &&
1923 		(current->nr_cpus_allowed  == 1);
1924 #else
1925 	return true;
1926 #endif
1927 }
1928 
1929 /* Per-process atomic flags. */
1930 #define PFA_NO_NEW_PRIVS		0	/* May not gain new privileges. */
1931 #define PFA_SPREAD_PAGE			1	/* Spread page cache over cpuset */
1932 #define PFA_SPREAD_SLAB			2	/* Spread some slab caches over cpuset */
1933 #define PFA_SPEC_SSB_DISABLE		3	/* Speculative Store Bypass disabled */
1934 #define PFA_SPEC_SSB_FORCE_DISABLE	4	/* Speculative Store Bypass force disabled*/
1935 #define PFA_SPEC_IB_DISABLE		5	/* Indirect branch speculation restricted */
1936 #define PFA_SPEC_IB_FORCE_DISABLE	6	/* Indirect branch speculation permanently restricted */
1937 #define PFA_SPEC_SSB_NOEXEC		7	/* Speculative Store Bypass clear on execve() */
1938 
1939 #define TASK_PFA_TEST(name, func)					\
1940 	static inline bool task_##func(struct task_struct *p)		\
1941 	{ return test_bit(PFA_##name, &p->atomic_flags); }
1942 
1943 #define TASK_PFA_SET(name, func)					\
1944 	static inline void task_set_##func(struct task_struct *p)	\
1945 	{ set_bit(PFA_##name, &p->atomic_flags); }
1946 
1947 #define TASK_PFA_CLEAR(name, func)					\
1948 	static inline void task_clear_##func(struct task_struct *p)	\
1949 	{ clear_bit(PFA_##name, &p->atomic_flags); }
1950 
TASK_PFA_TEST(NO_NEW_PRIVS,no_new_privs)1951 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
1952 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
1953 
1954 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
1955 TASK_PFA_SET(SPREAD_PAGE, spread_page)
1956 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
1957 
1958 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
1959 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
1960 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
1961 
1962 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable)
1963 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable)
1964 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable)
1965 
1966 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1967 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1968 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1969 
1970 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1971 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1972 
1973 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable)
1974 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable)
1975 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable)
1976 
1977 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1978 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1979 
1980 static inline void
1981 current_restore_flags(unsigned long orig_flags, unsigned long flags)
1982 {
1983 	current->flags &= ~flags;
1984 	current->flags |= orig_flags & flags;
1985 }
1986 
1987 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
1988 extern int task_can_attach(struct task_struct *p);
1989 extern int dl_bw_alloc(int cpu, u64 dl_bw);
1990 extern void dl_bw_free(int cpu, u64 dl_bw);
1991 #ifdef CONFIG_SMP
1992 
1993 /* do_set_cpus_allowed() - consider using set_cpus_allowed_ptr() instead */
1994 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
1995 
1996 /**
1997  * set_cpus_allowed_ptr - set CPU affinity mask of a task
1998  * @p: the task
1999  * @new_mask: CPU affinity mask
2000  *
2001  * Return: zero if successful, or a negative error code
2002  */
2003 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
2004 extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node);
2005 extern void release_user_cpus_ptr(struct task_struct *p);
2006 extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask);
2007 extern void force_compatible_cpus_allowed_ptr(struct task_struct *p);
2008 extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p);
2009 #else
do_set_cpus_allowed(struct task_struct * p,const struct cpumask * new_mask)2010 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
2011 {
2012 }
set_cpus_allowed_ptr(struct task_struct * p,const struct cpumask * new_mask)2013 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
2014 {
2015 	if (!cpumask_test_cpu(0, new_mask))
2016 		return -EINVAL;
2017 	return 0;
2018 }
dup_user_cpus_ptr(struct task_struct * dst,struct task_struct * src,int node)2019 static inline int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node)
2020 {
2021 	if (src->user_cpus_ptr)
2022 		return -EINVAL;
2023 	return 0;
2024 }
release_user_cpus_ptr(struct task_struct * p)2025 static inline void release_user_cpus_ptr(struct task_struct *p)
2026 {
2027 	WARN_ON(p->user_cpus_ptr);
2028 }
2029 
dl_task_check_affinity(struct task_struct * p,const struct cpumask * mask)2030 static inline int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask)
2031 {
2032 	return 0;
2033 }
2034 #endif
2035 
2036 extern int yield_to(struct task_struct *p, bool preempt);
2037 extern void set_user_nice(struct task_struct *p, long nice);
2038 extern int task_prio(const struct task_struct *p);
2039 
2040 /**
2041  * task_nice - return the nice value of a given task.
2042  * @p: the task in question.
2043  *
2044  * Return: The nice value [ -20 ... 0 ... 19 ].
2045  */
task_nice(const struct task_struct * p)2046 static inline int task_nice(const struct task_struct *p)
2047 {
2048 	return PRIO_TO_NICE((p)->static_prio);
2049 }
2050 
2051 extern int can_nice(const struct task_struct *p, const int nice);
2052 extern int task_curr(const struct task_struct *p);
2053 extern int idle_cpu(int cpu);
2054 extern int available_idle_cpu(int cpu);
2055 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *);
2056 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *);
2057 extern void sched_set_fifo(struct task_struct *p);
2058 extern void sched_set_fifo_low(struct task_struct *p);
2059 extern void sched_set_normal(struct task_struct *p, int nice);
2060 extern int sched_setattr(struct task_struct *, const struct sched_attr *);
2061 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *);
2062 extern struct task_struct *idle_task(int cpu);
2063 
2064 /**
2065  * is_idle_task - is the specified task an idle task?
2066  * @p: the task in question.
2067  *
2068  * Return: 1 if @p is an idle task. 0 otherwise.
2069  */
is_idle_task(const struct task_struct * p)2070 static __always_inline bool is_idle_task(const struct task_struct *p)
2071 {
2072 	return !!(p->flags & PF_IDLE);
2073 }
2074 
2075 extern struct task_struct *curr_task(int cpu);
2076 extern void ia64_set_curr_task(int cpu, struct task_struct *p);
2077 
2078 void yield(void);
2079 
2080 union thread_union {
2081 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK
2082 	struct task_struct task;
2083 #endif
2084 #ifndef CONFIG_THREAD_INFO_IN_TASK
2085 	struct thread_info thread_info;
2086 #endif
2087 	unsigned long stack[THREAD_SIZE/sizeof(long)];
2088 };
2089 
2090 #ifndef CONFIG_THREAD_INFO_IN_TASK
2091 extern struct thread_info init_thread_info;
2092 #endif
2093 
2094 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
2095 
2096 #ifdef CONFIG_THREAD_INFO_IN_TASK
2097 # define task_thread_info(task)	(&(task)->thread_info)
2098 #elif !defined(__HAVE_THREAD_FUNCTIONS)
2099 # define task_thread_info(task)	((struct thread_info *)(task)->stack)
2100 #endif
2101 
2102 /*
2103  * find a task by one of its numerical ids
2104  *
2105  * find_task_by_pid_ns():
2106  *      finds a task by its pid in the specified namespace
2107  * find_task_by_vpid():
2108  *      finds a task by its virtual pid
2109  *
2110  * see also find_vpid() etc in include/linux/pid.h
2111  */
2112 
2113 extern struct task_struct *find_task_by_vpid(pid_t nr);
2114 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns);
2115 
2116 /*
2117  * find a task by its virtual pid and get the task struct
2118  */
2119 extern struct task_struct *find_get_task_by_vpid(pid_t nr);
2120 
2121 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2122 extern int wake_up_process(struct task_struct *tsk);
2123 extern void wake_up_new_task(struct task_struct *tsk);
2124 
2125 #ifdef CONFIG_SMP
2126 extern void kick_process(struct task_struct *tsk);
2127 #else
kick_process(struct task_struct * tsk)2128 static inline void kick_process(struct task_struct *tsk) { }
2129 #endif
2130 
2131 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
2132 
set_task_comm(struct task_struct * tsk,const char * from)2133 static inline void set_task_comm(struct task_struct *tsk, const char *from)
2134 {
2135 	__set_task_comm(tsk, from, false);
2136 }
2137 
2138 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk);
2139 #define get_task_comm(buf, tsk) ({			\
2140 	BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN);	\
2141 	__get_task_comm(buf, sizeof(buf), tsk);		\
2142 })
2143 
2144 #ifdef CONFIG_SMP
scheduler_ipi(void)2145 static __always_inline void scheduler_ipi(void)
2146 {
2147 	/*
2148 	 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting
2149 	 * TIF_NEED_RESCHED remotely (for the first time) will also send
2150 	 * this IPI.
2151 	 */
2152 	preempt_fold_need_resched();
2153 }
2154 #else
scheduler_ipi(void)2155 static inline void scheduler_ipi(void) { }
2156 #endif
2157 
2158 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state);
2159 
2160 /*
2161  * Set thread flags in other task's structures.
2162  * See asm/thread_info.h for TIF_xxxx flags available:
2163  */
set_tsk_thread_flag(struct task_struct * tsk,int flag)2164 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2165 {
2166 	set_ti_thread_flag(task_thread_info(tsk), flag);
2167 }
2168 
clear_tsk_thread_flag(struct task_struct * tsk,int flag)2169 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2170 {
2171 	clear_ti_thread_flag(task_thread_info(tsk), flag);
2172 }
2173 
update_tsk_thread_flag(struct task_struct * tsk,int flag,bool value)2174 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag,
2175 					  bool value)
2176 {
2177 	update_ti_thread_flag(task_thread_info(tsk), flag, value);
2178 }
2179 
test_and_set_tsk_thread_flag(struct task_struct * tsk,int flag)2180 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2181 {
2182 	return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2183 }
2184 
test_and_clear_tsk_thread_flag(struct task_struct * tsk,int flag)2185 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2186 {
2187 	return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2188 }
2189 
test_tsk_thread_flag(struct task_struct * tsk,int flag)2190 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2191 {
2192 	return test_ti_thread_flag(task_thread_info(tsk), flag);
2193 }
2194 
set_tsk_need_resched(struct task_struct * tsk)2195 static inline void set_tsk_need_resched(struct task_struct *tsk)
2196 {
2197 	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2198 }
2199 
clear_tsk_need_resched(struct task_struct * tsk)2200 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2201 {
2202 	clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2203 }
2204 
test_tsk_need_resched(struct task_struct * tsk)2205 static inline int test_tsk_need_resched(struct task_struct *tsk)
2206 {
2207 	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2208 }
2209 
2210 /*
2211  * cond_resched() and cond_resched_lock(): latency reduction via
2212  * explicit rescheduling in places that are safe. The return
2213  * value indicates whether a reschedule was done in fact.
2214  * cond_resched_lock() will drop the spinlock before scheduling,
2215  */
2216 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC)
2217 extern int __cond_resched(void);
2218 
2219 #if defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL)
2220 
2221 void sched_dynamic_klp_enable(void);
2222 void sched_dynamic_klp_disable(void);
2223 
2224 DECLARE_STATIC_CALL(cond_resched, __cond_resched);
2225 
_cond_resched(void)2226 static __always_inline int _cond_resched(void)
2227 {
2228 	return static_call_mod(cond_resched)();
2229 }
2230 
2231 #elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY)
2232 
2233 extern int dynamic_cond_resched(void);
2234 
_cond_resched(void)2235 static __always_inline int _cond_resched(void)
2236 {
2237 	return dynamic_cond_resched();
2238 }
2239 
2240 #else /* !CONFIG_PREEMPTION */
2241 
_cond_resched(void)2242 static inline int _cond_resched(void)
2243 {
2244 	klp_sched_try_switch();
2245 	return __cond_resched();
2246 }
2247 
2248 #endif /* PREEMPT_DYNAMIC && CONFIG_HAVE_PREEMPT_DYNAMIC_CALL */
2249 
2250 #else /* CONFIG_PREEMPTION && !CONFIG_PREEMPT_DYNAMIC */
2251 
_cond_resched(void)2252 static inline int _cond_resched(void)
2253 {
2254 	klp_sched_try_switch();
2255 	return 0;
2256 }
2257 
2258 #endif /* !CONFIG_PREEMPTION || CONFIG_PREEMPT_DYNAMIC */
2259 
2260 #define cond_resched() ({			\
2261 	__might_resched(__FILE__, __LINE__, 0);	\
2262 	_cond_resched();			\
2263 })
2264 
2265 extern int __cond_resched_lock(spinlock_t *lock);
2266 extern int __cond_resched_rwlock_read(rwlock_t *lock);
2267 extern int __cond_resched_rwlock_write(rwlock_t *lock);
2268 
2269 #define MIGHT_RESCHED_RCU_SHIFT		8
2270 #define MIGHT_RESCHED_PREEMPT_MASK	((1U << MIGHT_RESCHED_RCU_SHIFT) - 1)
2271 
2272 #ifndef CONFIG_PREEMPT_RT
2273 /*
2274  * Non RT kernels have an elevated preempt count due to the held lock,
2275  * but are not allowed to be inside a RCU read side critical section
2276  */
2277 # define PREEMPT_LOCK_RESCHED_OFFSETS	PREEMPT_LOCK_OFFSET
2278 #else
2279 /*
2280  * spin/rw_lock() on RT implies rcu_read_lock(). The might_sleep() check in
2281  * cond_resched*lock() has to take that into account because it checks for
2282  * preempt_count() and rcu_preempt_depth().
2283  */
2284 # define PREEMPT_LOCK_RESCHED_OFFSETS	\
2285 	(PREEMPT_LOCK_OFFSET + (1U << MIGHT_RESCHED_RCU_SHIFT))
2286 #endif
2287 
2288 #define cond_resched_lock(lock) ({						\
2289 	__might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS);	\
2290 	__cond_resched_lock(lock);						\
2291 })
2292 
2293 #define cond_resched_rwlock_read(lock) ({					\
2294 	__might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS);	\
2295 	__cond_resched_rwlock_read(lock);					\
2296 })
2297 
2298 #define cond_resched_rwlock_write(lock) ({					\
2299 	__might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS);	\
2300 	__cond_resched_rwlock_write(lock);					\
2301 })
2302 
cond_resched_rcu(void)2303 static inline void cond_resched_rcu(void)
2304 {
2305 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
2306 	rcu_read_unlock();
2307 	cond_resched();
2308 	rcu_read_lock();
2309 #endif
2310 }
2311 
2312 #ifdef CONFIG_PREEMPT_DYNAMIC
2313 
2314 extern bool preempt_model_none(void);
2315 extern bool preempt_model_voluntary(void);
2316 extern bool preempt_model_full(void);
2317 
2318 #else
2319 
preempt_model_none(void)2320 static inline bool preempt_model_none(void)
2321 {
2322 	return IS_ENABLED(CONFIG_PREEMPT_NONE);
2323 }
preempt_model_voluntary(void)2324 static inline bool preempt_model_voluntary(void)
2325 {
2326 	return IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY);
2327 }
preempt_model_full(void)2328 static inline bool preempt_model_full(void)
2329 {
2330 	return IS_ENABLED(CONFIG_PREEMPT);
2331 }
2332 
2333 #endif
2334 
preempt_model_rt(void)2335 static inline bool preempt_model_rt(void)
2336 {
2337 	return IS_ENABLED(CONFIG_PREEMPT_RT);
2338 }
2339 
2340 /*
2341  * Does the preemption model allow non-cooperative preemption?
2342  *
2343  * For !CONFIG_PREEMPT_DYNAMIC kernels this is an exact match with
2344  * CONFIG_PREEMPTION; for CONFIG_PREEMPT_DYNAMIC this doesn't work as the
2345  * kernel is *built* with CONFIG_PREEMPTION=y but may run with e.g. the
2346  * PREEMPT_NONE model.
2347  */
preempt_model_preemptible(void)2348 static inline bool preempt_model_preemptible(void)
2349 {
2350 	return preempt_model_full() || preempt_model_rt();
2351 }
2352 
2353 /*
2354  * Does a critical section need to be broken due to another
2355  * task waiting?: (technically does not depend on CONFIG_PREEMPTION,
2356  * but a general need for low latency)
2357  */
spin_needbreak(spinlock_t * lock)2358 static inline int spin_needbreak(spinlock_t *lock)
2359 {
2360 #ifdef CONFIG_PREEMPTION
2361 	return spin_is_contended(lock);
2362 #else
2363 	return 0;
2364 #endif
2365 }
2366 
2367 /*
2368  * Check if a rwlock is contended.
2369  * Returns non-zero if there is another task waiting on the rwlock.
2370  * Returns zero if the lock is not contended or the system / underlying
2371  * rwlock implementation does not support contention detection.
2372  * Technically does not depend on CONFIG_PREEMPTION, but a general need
2373  * for low latency.
2374  */
rwlock_needbreak(rwlock_t * lock)2375 static inline int rwlock_needbreak(rwlock_t *lock)
2376 {
2377 #ifdef CONFIG_PREEMPTION
2378 	return rwlock_is_contended(lock);
2379 #else
2380 	return 0;
2381 #endif
2382 }
2383 
need_resched(void)2384 static __always_inline bool need_resched(void)
2385 {
2386 	return unlikely(tif_need_resched());
2387 }
2388 
2389 /*
2390  * Wrappers for p->thread_info->cpu access. No-op on UP.
2391  */
2392 #ifdef CONFIG_SMP
2393 
task_cpu(const struct task_struct * p)2394 static inline unsigned int task_cpu(const struct task_struct *p)
2395 {
2396 	return READ_ONCE(task_thread_info(p)->cpu);
2397 }
2398 
2399 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2400 
2401 #else
2402 
task_cpu(const struct task_struct * p)2403 static inline unsigned int task_cpu(const struct task_struct *p)
2404 {
2405 	return 0;
2406 }
2407 
set_task_cpu(struct task_struct * p,unsigned int cpu)2408 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2409 {
2410 }
2411 
2412 #endif /* CONFIG_SMP */
2413 
2414 extern bool sched_task_on_rq(struct task_struct *p);
2415 extern unsigned long get_wchan(struct task_struct *p);
2416 extern struct task_struct *cpu_curr_snapshot(int cpu);
2417 
2418 /*
2419  * In order to reduce various lock holder preemption latencies provide an
2420  * interface to see if a vCPU is currently running or not.
2421  *
2422  * This allows us to terminate optimistic spin loops and block, analogous to
2423  * the native optimistic spin heuristic of testing if the lock owner task is
2424  * running or not.
2425  */
2426 #ifndef vcpu_is_preempted
vcpu_is_preempted(int cpu)2427 static inline bool vcpu_is_preempted(int cpu)
2428 {
2429 	return false;
2430 }
2431 #endif
2432 
2433 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2434 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2435 
2436 #ifndef TASK_SIZE_OF
2437 #define TASK_SIZE_OF(tsk)	TASK_SIZE
2438 #endif
2439 
2440 #ifdef CONFIG_SMP
owner_on_cpu(struct task_struct * owner)2441 static inline bool owner_on_cpu(struct task_struct *owner)
2442 {
2443 	/*
2444 	 * As lock holder preemption issue, we both skip spinning if
2445 	 * task is not on cpu or its cpu is preempted
2446 	 */
2447 	return READ_ONCE(owner->on_cpu) && !vcpu_is_preempted(task_cpu(owner));
2448 }
2449 
2450 /* Returns effective CPU energy utilization, as seen by the scheduler */
2451 unsigned long sched_cpu_util(int cpu);
2452 #endif /* CONFIG_SMP */
2453 
2454 #ifdef CONFIG_RSEQ
2455 
2456 /*
2457  * Map the event mask on the user-space ABI enum rseq_cs_flags
2458  * for direct mask checks.
2459  */
2460 enum rseq_event_mask_bits {
2461 	RSEQ_EVENT_PREEMPT_BIT	= RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT,
2462 	RSEQ_EVENT_SIGNAL_BIT	= RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT,
2463 	RSEQ_EVENT_MIGRATE_BIT	= RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT,
2464 };
2465 
2466 enum rseq_event_mask {
2467 	RSEQ_EVENT_PREEMPT	= (1U << RSEQ_EVENT_PREEMPT_BIT),
2468 	RSEQ_EVENT_SIGNAL	= (1U << RSEQ_EVENT_SIGNAL_BIT),
2469 	RSEQ_EVENT_MIGRATE	= (1U << RSEQ_EVENT_MIGRATE_BIT),
2470 };
2471 
rseq_set_notify_resume(struct task_struct * t)2472 static inline void rseq_set_notify_resume(struct task_struct *t)
2473 {
2474 	if (t->rseq)
2475 		set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
2476 }
2477 
2478 void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs);
2479 
rseq_handle_notify_resume(struct ksignal * ksig,struct pt_regs * regs)2480 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
2481 					     struct pt_regs *regs)
2482 {
2483 	if (current->rseq)
2484 		__rseq_handle_notify_resume(ksig, regs);
2485 }
2486 
rseq_signal_deliver(struct ksignal * ksig,struct pt_regs * regs)2487 static inline void rseq_signal_deliver(struct ksignal *ksig,
2488 				       struct pt_regs *regs)
2489 {
2490 	preempt_disable();
2491 	__set_bit(RSEQ_EVENT_SIGNAL_BIT, &current->rseq_event_mask);
2492 	preempt_enable();
2493 	rseq_handle_notify_resume(ksig, regs);
2494 }
2495 
2496 /* rseq_preempt() requires preemption to be disabled. */
rseq_preempt(struct task_struct * t)2497 static inline void rseq_preempt(struct task_struct *t)
2498 {
2499 	__set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask);
2500 	rseq_set_notify_resume(t);
2501 }
2502 
2503 /* rseq_migrate() requires preemption to be disabled. */
rseq_migrate(struct task_struct * t)2504 static inline void rseq_migrate(struct task_struct *t)
2505 {
2506 	__set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask);
2507 	rseq_set_notify_resume(t);
2508 }
2509 
2510 /*
2511  * If parent process has a registered restartable sequences area, the
2512  * child inherits. Unregister rseq for a clone with CLONE_VM set.
2513  */
rseq_fork(struct task_struct * t,unsigned long clone_flags)2514 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
2515 {
2516 	if (clone_flags & CLONE_VM) {
2517 		t->rseq = NULL;
2518 		t->rseq_len = 0;
2519 		t->rseq_sig = 0;
2520 		t->rseq_event_mask = 0;
2521 	} else {
2522 		t->rseq = current->rseq;
2523 		t->rseq_len = current->rseq_len;
2524 		t->rseq_sig = current->rseq_sig;
2525 		t->rseq_event_mask = current->rseq_event_mask;
2526 	}
2527 }
2528 
rseq_execve(struct task_struct * t)2529 static inline void rseq_execve(struct task_struct *t)
2530 {
2531 	t->rseq = NULL;
2532 	t->rseq_len = 0;
2533 	t->rseq_sig = 0;
2534 	t->rseq_event_mask = 0;
2535 }
2536 
2537 #else
2538 
rseq_set_notify_resume(struct task_struct * t)2539 static inline void rseq_set_notify_resume(struct task_struct *t)
2540 {
2541 }
rseq_handle_notify_resume(struct ksignal * ksig,struct pt_regs * regs)2542 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
2543 					     struct pt_regs *regs)
2544 {
2545 }
rseq_signal_deliver(struct ksignal * ksig,struct pt_regs * regs)2546 static inline void rseq_signal_deliver(struct ksignal *ksig,
2547 				       struct pt_regs *regs)
2548 {
2549 }
rseq_preempt(struct task_struct * t)2550 static inline void rseq_preempt(struct task_struct *t)
2551 {
2552 }
rseq_migrate(struct task_struct * t)2553 static inline void rseq_migrate(struct task_struct *t)
2554 {
2555 }
rseq_fork(struct task_struct * t,unsigned long clone_flags)2556 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
2557 {
2558 }
rseq_execve(struct task_struct * t)2559 static inline void rseq_execve(struct task_struct *t)
2560 {
2561 }
2562 
2563 #endif
2564 
2565 #ifdef CONFIG_DEBUG_RSEQ
2566 
2567 void rseq_syscall(struct pt_regs *regs);
2568 
2569 #else
2570 
rseq_syscall(struct pt_regs * regs)2571 static inline void rseq_syscall(struct pt_regs *regs)
2572 {
2573 }
2574 
2575 #endif
2576 
2577 #ifdef CONFIG_SCHED_CORE
2578 extern void sched_core_free(struct task_struct *tsk);
2579 extern void sched_core_fork(struct task_struct *p);
2580 extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type,
2581 				unsigned long uaddr);
2582 extern int sched_core_idle_cpu(int cpu);
2583 #else
sched_core_free(struct task_struct * tsk)2584 static inline void sched_core_free(struct task_struct *tsk) { }
sched_core_fork(struct task_struct * p)2585 static inline void sched_core_fork(struct task_struct *p) { }
sched_core_idle_cpu(int cpu)2586 static inline int sched_core_idle_cpu(int cpu) { return idle_cpu(cpu); }
2587 #endif
2588 
2589 extern void sched_set_stop_task(int cpu, struct task_struct *stop);
2590 
2591 #endif
2592