xref: /openbmc/linux/include/linux/sched.h (revision 0d6b3528)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_SCHED_H
3 #define _LINUX_SCHED_H
4 
5 /*
6  * Define 'struct task_struct' and provide the main scheduler
7  * APIs (schedule(), wakeup variants, etc.)
8  */
9 
10 #include <uapi/linux/sched.h>
11 
12 #include <asm/current.h>
13 
14 #include <linux/pid.h>
15 #include <linux/sem.h>
16 #include <linux/shm.h>
17 #include <linux/kmsan_types.h>
18 #include <linux/mutex.h>
19 #include <linux/plist.h>
20 #include <linux/hrtimer.h>
21 #include <linux/irqflags.h>
22 #include <linux/seccomp.h>
23 #include <linux/nodemask.h>
24 #include <linux/rcupdate.h>
25 #include <linux/refcount.h>
26 #include <linux/resource.h>
27 #include <linux/latencytop.h>
28 #include <linux/sched/prio.h>
29 #include <linux/sched/types.h>
30 #include <linux/signal_types.h>
31 #include <linux/syscall_user_dispatch.h>
32 #include <linux/mm_types_task.h>
33 #include <linux/task_io_accounting.h>
34 #include <linux/posix-timers.h>
35 #include <linux/rseq.h>
36 #include <linux/seqlock.h>
37 #include <linux/kcsan.h>
38 #include <linux/rv.h>
39 #include <linux/livepatch_sched.h>
40 #include <asm/kmap_size.h>
41 
42 /* task_struct member predeclarations (sorted alphabetically): */
43 struct audit_context;
44 struct bio_list;
45 struct blk_plug;
46 struct bpf_local_storage;
47 struct bpf_run_ctx;
48 struct capture_control;
49 struct cfs_rq;
50 struct fs_struct;
51 struct futex_pi_state;
52 struct io_context;
53 struct io_uring_task;
54 struct mempolicy;
55 struct nameidata;
56 struct nsproxy;
57 struct perf_event_context;
58 struct pid_namespace;
59 struct pipe_inode_info;
60 struct rcu_node;
61 struct reclaim_state;
62 struct robust_list_head;
63 struct root_domain;
64 struct rq;
65 struct sched_attr;
66 struct sched_param;
67 struct seq_file;
68 struct sighand_struct;
69 struct signal_struct;
70 struct task_delay_info;
71 struct task_group;
72 struct user_event_mm;
73 
74 /*
75  * Task state bitmask. NOTE! These bits are also
76  * encoded in fs/proc/array.c: get_task_state().
77  *
78  * We have two separate sets of flags: task->__state
79  * is about runnability, while task->exit_state are
80  * about the task exiting. Confusing, but this way
81  * modifying one set can't modify the other one by
82  * mistake.
83  */
84 
85 /* Used in tsk->__state: */
86 #define TASK_RUNNING			0x00000000
87 #define TASK_INTERRUPTIBLE		0x00000001
88 #define TASK_UNINTERRUPTIBLE		0x00000002
89 #define __TASK_STOPPED			0x00000004
90 #define __TASK_TRACED			0x00000008
91 /* Used in tsk->exit_state: */
92 #define EXIT_DEAD			0x00000010
93 #define EXIT_ZOMBIE			0x00000020
94 #define EXIT_TRACE			(EXIT_ZOMBIE | EXIT_DEAD)
95 /* Used in tsk->__state again: */
96 #define TASK_PARKED			0x00000040
97 #define TASK_DEAD			0x00000080
98 #define TASK_WAKEKILL			0x00000100
99 #define TASK_WAKING			0x00000200
100 #define TASK_NOLOAD			0x00000400
101 #define TASK_NEW			0x00000800
102 #define TASK_RTLOCK_WAIT		0x00001000
103 #define TASK_FREEZABLE			0x00002000
104 #define __TASK_FREEZABLE_UNSAFE	       (0x00004000 * IS_ENABLED(CONFIG_LOCKDEP))
105 #define TASK_FROZEN			0x00008000
106 #define TASK_STATE_MAX			0x00010000
107 
108 #define TASK_ANY			(TASK_STATE_MAX-1)
109 
110 /*
111  * DO NOT ADD ANY NEW USERS !
112  */
113 #define TASK_FREEZABLE_UNSAFE		(TASK_FREEZABLE | __TASK_FREEZABLE_UNSAFE)
114 
115 /* Convenience macros for the sake of set_current_state: */
116 #define TASK_KILLABLE			(TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
117 #define TASK_STOPPED			(TASK_WAKEKILL | __TASK_STOPPED)
118 #define TASK_TRACED			__TASK_TRACED
119 
120 #define TASK_IDLE			(TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
121 
122 /* Convenience macros for the sake of wake_up(): */
123 #define TASK_NORMAL			(TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
124 
125 /* get_task_state(): */
126 #define TASK_REPORT			(TASK_RUNNING | TASK_INTERRUPTIBLE | \
127 					 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
128 					 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
129 					 TASK_PARKED)
130 
131 #define task_is_running(task)		(READ_ONCE((task)->__state) == TASK_RUNNING)
132 
133 #define task_is_traced(task)		((READ_ONCE(task->jobctl) & JOBCTL_TRACED) != 0)
134 #define task_is_stopped(task)		((READ_ONCE(task->jobctl) & JOBCTL_STOPPED) != 0)
135 #define task_is_stopped_or_traced(task)	((READ_ONCE(task->jobctl) & (JOBCTL_STOPPED | JOBCTL_TRACED)) != 0)
136 
137 /*
138  * Special states are those that do not use the normal wait-loop pattern. See
139  * the comment with set_special_state().
140  */
141 #define is_special_task_state(state)				\
142 	((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD))
143 
144 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
145 # define debug_normal_state_change(state_value)				\
146 	do {								\
147 		WARN_ON_ONCE(is_special_task_state(state_value));	\
148 		current->task_state_change = _THIS_IP_;			\
149 	} while (0)
150 
151 # define debug_special_state_change(state_value)			\
152 	do {								\
153 		WARN_ON_ONCE(!is_special_task_state(state_value));	\
154 		current->task_state_change = _THIS_IP_;			\
155 	} while (0)
156 
157 # define debug_rtlock_wait_set_state()					\
158 	do {								 \
159 		current->saved_state_change = current->task_state_change;\
160 		current->task_state_change = _THIS_IP_;			 \
161 	} while (0)
162 
163 # define debug_rtlock_wait_restore_state()				\
164 	do {								 \
165 		current->task_state_change = current->saved_state_change;\
166 	} while (0)
167 
168 #else
169 # define debug_normal_state_change(cond)	do { } while (0)
170 # define debug_special_state_change(cond)	do { } while (0)
171 # define debug_rtlock_wait_set_state()		do { } while (0)
172 # define debug_rtlock_wait_restore_state()	do { } while (0)
173 #endif
174 
175 /*
176  * set_current_state() includes a barrier so that the write of current->__state
177  * is correctly serialised wrt the caller's subsequent test of whether to
178  * actually sleep:
179  *
180  *   for (;;) {
181  *	set_current_state(TASK_UNINTERRUPTIBLE);
182  *	if (CONDITION)
183  *	   break;
184  *
185  *	schedule();
186  *   }
187  *   __set_current_state(TASK_RUNNING);
188  *
189  * If the caller does not need such serialisation (because, for instance, the
190  * CONDITION test and condition change and wakeup are under the same lock) then
191  * use __set_current_state().
192  *
193  * The above is typically ordered against the wakeup, which does:
194  *
195  *   CONDITION = 1;
196  *   wake_up_state(p, TASK_UNINTERRUPTIBLE);
197  *
198  * where wake_up_state()/try_to_wake_up() executes a full memory barrier before
199  * accessing p->__state.
200  *
201  * Wakeup will do: if (@state & p->__state) p->__state = TASK_RUNNING, that is,
202  * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
203  * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
204  *
205  * However, with slightly different timing the wakeup TASK_RUNNING store can
206  * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not
207  * a problem either because that will result in one extra go around the loop
208  * and our @cond test will save the day.
209  *
210  * Also see the comments of try_to_wake_up().
211  */
212 #define __set_current_state(state_value)				\
213 	do {								\
214 		debug_normal_state_change((state_value));		\
215 		WRITE_ONCE(current->__state, (state_value));		\
216 	} while (0)
217 
218 #define set_current_state(state_value)					\
219 	do {								\
220 		debug_normal_state_change((state_value));		\
221 		smp_store_mb(current->__state, (state_value));		\
222 	} while (0)
223 
224 /*
225  * set_special_state() should be used for those states when the blocking task
226  * can not use the regular condition based wait-loop. In that case we must
227  * serialize against wakeups such that any possible in-flight TASK_RUNNING
228  * stores will not collide with our state change.
229  */
230 #define set_special_state(state_value)					\
231 	do {								\
232 		unsigned long flags; /* may shadow */			\
233 									\
234 		raw_spin_lock_irqsave(&current->pi_lock, flags);	\
235 		debug_special_state_change((state_value));		\
236 		WRITE_ONCE(current->__state, (state_value));		\
237 		raw_spin_unlock_irqrestore(&current->pi_lock, flags);	\
238 	} while (0)
239 
240 /*
241  * PREEMPT_RT specific variants for "sleeping" spin/rwlocks
242  *
243  * RT's spin/rwlock substitutions are state preserving. The state of the
244  * task when blocking on the lock is saved in task_struct::saved_state and
245  * restored after the lock has been acquired.  These operations are
246  * serialized by task_struct::pi_lock against try_to_wake_up(). Any non RT
247  * lock related wakeups while the task is blocked on the lock are
248  * redirected to operate on task_struct::saved_state to ensure that these
249  * are not dropped. On restore task_struct::saved_state is set to
250  * TASK_RUNNING so any wakeup attempt redirected to saved_state will fail.
251  *
252  * The lock operation looks like this:
253  *
254  *	current_save_and_set_rtlock_wait_state();
255  *	for (;;) {
256  *		if (try_lock())
257  *			break;
258  *		raw_spin_unlock_irq(&lock->wait_lock);
259  *		schedule_rtlock();
260  *		raw_spin_lock_irq(&lock->wait_lock);
261  *		set_current_state(TASK_RTLOCK_WAIT);
262  *	}
263  *	current_restore_rtlock_saved_state();
264  */
265 #define current_save_and_set_rtlock_wait_state()			\
266 	do {								\
267 		lockdep_assert_irqs_disabled();				\
268 		raw_spin_lock(&current->pi_lock);			\
269 		current->saved_state = current->__state;		\
270 		debug_rtlock_wait_set_state();				\
271 		WRITE_ONCE(current->__state, TASK_RTLOCK_WAIT);		\
272 		raw_spin_unlock(&current->pi_lock);			\
273 	} while (0);
274 
275 #define current_restore_rtlock_saved_state()				\
276 	do {								\
277 		lockdep_assert_irqs_disabled();				\
278 		raw_spin_lock(&current->pi_lock);			\
279 		debug_rtlock_wait_restore_state();			\
280 		WRITE_ONCE(current->__state, current->saved_state);	\
281 		current->saved_state = TASK_RUNNING;			\
282 		raw_spin_unlock(&current->pi_lock);			\
283 	} while (0);
284 
285 #define get_current_state()	READ_ONCE(current->__state)
286 
287 /*
288  * Define the task command name length as enum, then it can be visible to
289  * BPF programs.
290  */
291 enum {
292 	TASK_COMM_LEN = 16,
293 };
294 
295 extern void scheduler_tick(void);
296 
297 #define	MAX_SCHEDULE_TIMEOUT		LONG_MAX
298 
299 extern long schedule_timeout(long timeout);
300 extern long schedule_timeout_interruptible(long timeout);
301 extern long schedule_timeout_killable(long timeout);
302 extern long schedule_timeout_uninterruptible(long timeout);
303 extern long schedule_timeout_idle(long timeout);
304 asmlinkage void schedule(void);
305 extern void schedule_preempt_disabled(void);
306 asmlinkage void preempt_schedule_irq(void);
307 #ifdef CONFIG_PREEMPT_RT
308  extern void schedule_rtlock(void);
309 #endif
310 
311 extern int __must_check io_schedule_prepare(void);
312 extern void io_schedule_finish(int token);
313 extern long io_schedule_timeout(long timeout);
314 extern void io_schedule(void);
315 
316 /**
317  * struct prev_cputime - snapshot of system and user cputime
318  * @utime: time spent in user mode
319  * @stime: time spent in system mode
320  * @lock: protects the above two fields
321  *
322  * Stores previous user/system time values such that we can guarantee
323  * monotonicity.
324  */
325 struct prev_cputime {
326 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
327 	u64				utime;
328 	u64				stime;
329 	raw_spinlock_t			lock;
330 #endif
331 };
332 
333 enum vtime_state {
334 	/* Task is sleeping or running in a CPU with VTIME inactive: */
335 	VTIME_INACTIVE = 0,
336 	/* Task is idle */
337 	VTIME_IDLE,
338 	/* Task runs in kernelspace in a CPU with VTIME active: */
339 	VTIME_SYS,
340 	/* Task runs in userspace in a CPU with VTIME active: */
341 	VTIME_USER,
342 	/* Task runs as guests in a CPU with VTIME active: */
343 	VTIME_GUEST,
344 };
345 
346 struct vtime {
347 	seqcount_t		seqcount;
348 	unsigned long long	starttime;
349 	enum vtime_state	state;
350 	unsigned int		cpu;
351 	u64			utime;
352 	u64			stime;
353 	u64			gtime;
354 };
355 
356 /*
357  * Utilization clamp constraints.
358  * @UCLAMP_MIN:	Minimum utilization
359  * @UCLAMP_MAX:	Maximum utilization
360  * @UCLAMP_CNT:	Utilization clamp constraints count
361  */
362 enum uclamp_id {
363 	UCLAMP_MIN = 0,
364 	UCLAMP_MAX,
365 	UCLAMP_CNT
366 };
367 
368 #ifdef CONFIG_SMP
369 extern struct root_domain def_root_domain;
370 extern struct mutex sched_domains_mutex;
371 #endif
372 
373 struct sched_info {
374 #ifdef CONFIG_SCHED_INFO
375 	/* Cumulative counters: */
376 
377 	/* # of times we have run on this CPU: */
378 	unsigned long			pcount;
379 
380 	/* Time spent waiting on a runqueue: */
381 	unsigned long long		run_delay;
382 
383 	/* Timestamps: */
384 
385 	/* When did we last run on a CPU? */
386 	unsigned long long		last_arrival;
387 
388 	/* When were we last queued to run? */
389 	unsigned long long		last_queued;
390 
391 #endif /* CONFIG_SCHED_INFO */
392 };
393 
394 /*
395  * Integer metrics need fixed point arithmetic, e.g., sched/fair
396  * has a few: load, load_avg, util_avg, freq, and capacity.
397  *
398  * We define a basic fixed point arithmetic range, and then formalize
399  * all these metrics based on that basic range.
400  */
401 # define SCHED_FIXEDPOINT_SHIFT		10
402 # define SCHED_FIXEDPOINT_SCALE		(1L << SCHED_FIXEDPOINT_SHIFT)
403 
404 /* Increase resolution of cpu_capacity calculations */
405 # define SCHED_CAPACITY_SHIFT		SCHED_FIXEDPOINT_SHIFT
406 # define SCHED_CAPACITY_SCALE		(1L << SCHED_CAPACITY_SHIFT)
407 
408 struct load_weight {
409 	unsigned long			weight;
410 	u32				inv_weight;
411 };
412 
413 /**
414  * struct util_est - Estimation utilization of FAIR tasks
415  * @enqueued: instantaneous estimated utilization of a task/cpu
416  * @ewma:     the Exponential Weighted Moving Average (EWMA)
417  *            utilization of a task
418  *
419  * Support data structure to track an Exponential Weighted Moving Average
420  * (EWMA) of a FAIR task's utilization. New samples are added to the moving
421  * average each time a task completes an activation. Sample's weight is chosen
422  * so that the EWMA will be relatively insensitive to transient changes to the
423  * task's workload.
424  *
425  * The enqueued attribute has a slightly different meaning for tasks and cpus:
426  * - task:   the task's util_avg at last task dequeue time
427  * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU
428  * Thus, the util_est.enqueued of a task represents the contribution on the
429  * estimated utilization of the CPU where that task is currently enqueued.
430  *
431  * Only for tasks we track a moving average of the past instantaneous
432  * estimated utilization. This allows to absorb sporadic drops in utilization
433  * of an otherwise almost periodic task.
434  *
435  * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg
436  * updates. When a task is dequeued, its util_est should not be updated if its
437  * util_avg has not been updated in the meantime.
438  * This information is mapped into the MSB bit of util_est.enqueued at dequeue
439  * time. Since max value of util_est.enqueued for a task is 1024 (PELT util_avg
440  * for a task) it is safe to use MSB.
441  */
442 struct util_est {
443 	unsigned int			enqueued;
444 	unsigned int			ewma;
445 #define UTIL_EST_WEIGHT_SHIFT		2
446 #define UTIL_AVG_UNCHANGED		0x80000000
447 } __attribute__((__aligned__(sizeof(u64))));
448 
449 /*
450  * The load/runnable/util_avg accumulates an infinite geometric series
451  * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c).
452  *
453  * [load_avg definition]
454  *
455  *   load_avg = runnable% * scale_load_down(load)
456  *
457  * [runnable_avg definition]
458  *
459  *   runnable_avg = runnable% * SCHED_CAPACITY_SCALE
460  *
461  * [util_avg definition]
462  *
463  *   util_avg = running% * SCHED_CAPACITY_SCALE
464  *
465  * where runnable% is the time ratio that a sched_entity is runnable and
466  * running% the time ratio that a sched_entity is running.
467  *
468  * For cfs_rq, they are the aggregated values of all runnable and blocked
469  * sched_entities.
470  *
471  * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU
472  * capacity scaling. The scaling is done through the rq_clock_pelt that is used
473  * for computing those signals (see update_rq_clock_pelt())
474  *
475  * N.B., the above ratios (runnable% and running%) themselves are in the
476  * range of [0, 1]. To do fixed point arithmetics, we therefore scale them
477  * to as large a range as necessary. This is for example reflected by
478  * util_avg's SCHED_CAPACITY_SCALE.
479  *
480  * [Overflow issue]
481  *
482  * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
483  * with the highest load (=88761), always runnable on a single cfs_rq,
484  * and should not overflow as the number already hits PID_MAX_LIMIT.
485  *
486  * For all other cases (including 32-bit kernels), struct load_weight's
487  * weight will overflow first before we do, because:
488  *
489  *    Max(load_avg) <= Max(load.weight)
490  *
491  * Then it is the load_weight's responsibility to consider overflow
492  * issues.
493  */
494 struct sched_avg {
495 	u64				last_update_time;
496 	u64				load_sum;
497 	u64				runnable_sum;
498 	u32				util_sum;
499 	u32				period_contrib;
500 	unsigned long			load_avg;
501 	unsigned long			runnable_avg;
502 	unsigned long			util_avg;
503 	struct util_est			util_est;
504 } ____cacheline_aligned;
505 
506 struct sched_statistics {
507 #ifdef CONFIG_SCHEDSTATS
508 	u64				wait_start;
509 	u64				wait_max;
510 	u64				wait_count;
511 	u64				wait_sum;
512 	u64				iowait_count;
513 	u64				iowait_sum;
514 
515 	u64				sleep_start;
516 	u64				sleep_max;
517 	s64				sum_sleep_runtime;
518 
519 	u64				block_start;
520 	u64				block_max;
521 	s64				sum_block_runtime;
522 
523 	u64				exec_max;
524 	u64				slice_max;
525 
526 	u64				nr_migrations_cold;
527 	u64				nr_failed_migrations_affine;
528 	u64				nr_failed_migrations_running;
529 	u64				nr_failed_migrations_hot;
530 	u64				nr_forced_migrations;
531 
532 	u64				nr_wakeups;
533 	u64				nr_wakeups_sync;
534 	u64				nr_wakeups_migrate;
535 	u64				nr_wakeups_local;
536 	u64				nr_wakeups_remote;
537 	u64				nr_wakeups_affine;
538 	u64				nr_wakeups_affine_attempts;
539 	u64				nr_wakeups_passive;
540 	u64				nr_wakeups_idle;
541 
542 #ifdef CONFIG_SCHED_CORE
543 	u64				core_forceidle_sum;
544 #endif
545 #endif /* CONFIG_SCHEDSTATS */
546 } ____cacheline_aligned;
547 
548 struct sched_entity {
549 	/* For load-balancing: */
550 	struct load_weight		load;
551 	struct rb_node			run_node;
552 	u64				deadline;
553 	u64				min_deadline;
554 
555 	struct list_head		group_node;
556 	unsigned int			on_rq;
557 
558 	u64				exec_start;
559 	u64				sum_exec_runtime;
560 	u64				prev_sum_exec_runtime;
561 	u64				vruntime;
562 	s64				vlag;
563 	u64				slice;
564 
565 	u64				nr_migrations;
566 
567 #ifdef CONFIG_FAIR_GROUP_SCHED
568 	int				depth;
569 	struct sched_entity		*parent;
570 	/* rq on which this entity is (to be) queued: */
571 	struct cfs_rq			*cfs_rq;
572 	/* rq "owned" by this entity/group: */
573 	struct cfs_rq			*my_q;
574 	/* cached value of my_q->h_nr_running */
575 	unsigned long			runnable_weight;
576 #endif
577 
578 #ifdef CONFIG_SMP
579 	/*
580 	 * Per entity load average tracking.
581 	 *
582 	 * Put into separate cache line so it does not
583 	 * collide with read-mostly values above.
584 	 */
585 	struct sched_avg		avg;
586 #endif
587 };
588 
589 struct sched_rt_entity {
590 	struct list_head		run_list;
591 	unsigned long			timeout;
592 	unsigned long			watchdog_stamp;
593 	unsigned int			time_slice;
594 	unsigned short			on_rq;
595 	unsigned short			on_list;
596 
597 	struct sched_rt_entity		*back;
598 #ifdef CONFIG_RT_GROUP_SCHED
599 	struct sched_rt_entity		*parent;
600 	/* rq on which this entity is (to be) queued: */
601 	struct rt_rq			*rt_rq;
602 	/* rq "owned" by this entity/group: */
603 	struct rt_rq			*my_q;
604 #endif
605 } __randomize_layout;
606 
607 struct sched_dl_entity {
608 	struct rb_node			rb_node;
609 
610 	/*
611 	 * Original scheduling parameters. Copied here from sched_attr
612 	 * during sched_setattr(), they will remain the same until
613 	 * the next sched_setattr().
614 	 */
615 	u64				dl_runtime;	/* Maximum runtime for each instance	*/
616 	u64				dl_deadline;	/* Relative deadline of each instance	*/
617 	u64				dl_period;	/* Separation of two instances (period) */
618 	u64				dl_bw;		/* dl_runtime / dl_period		*/
619 	u64				dl_density;	/* dl_runtime / dl_deadline		*/
620 
621 	/*
622 	 * Actual scheduling parameters. Initialized with the values above,
623 	 * they are continuously updated during task execution. Note that
624 	 * the remaining runtime could be < 0 in case we are in overrun.
625 	 */
626 	s64				runtime;	/* Remaining runtime for this instance	*/
627 	u64				deadline;	/* Absolute deadline for this instance	*/
628 	unsigned int			flags;		/* Specifying the scheduler behaviour	*/
629 
630 	/*
631 	 * Some bool flags:
632 	 *
633 	 * @dl_throttled tells if we exhausted the runtime. If so, the
634 	 * task has to wait for a replenishment to be performed at the
635 	 * next firing of dl_timer.
636 	 *
637 	 * @dl_yielded tells if task gave up the CPU before consuming
638 	 * all its available runtime during the last job.
639 	 *
640 	 * @dl_non_contending tells if the task is inactive while still
641 	 * contributing to the active utilization. In other words, it
642 	 * indicates if the inactive timer has been armed and its handler
643 	 * has not been executed yet. This flag is useful to avoid race
644 	 * conditions between the inactive timer handler and the wakeup
645 	 * code.
646 	 *
647 	 * @dl_overrun tells if the task asked to be informed about runtime
648 	 * overruns.
649 	 */
650 	unsigned int			dl_throttled      : 1;
651 	unsigned int			dl_yielded        : 1;
652 	unsigned int			dl_non_contending : 1;
653 	unsigned int			dl_overrun	  : 1;
654 
655 	/*
656 	 * Bandwidth enforcement timer. Each -deadline task has its
657 	 * own bandwidth to be enforced, thus we need one timer per task.
658 	 */
659 	struct hrtimer			dl_timer;
660 
661 	/*
662 	 * Inactive timer, responsible for decreasing the active utilization
663 	 * at the "0-lag time". When a -deadline task blocks, it contributes
664 	 * to GRUB's active utilization until the "0-lag time", hence a
665 	 * timer is needed to decrease the active utilization at the correct
666 	 * time.
667 	 */
668 	struct hrtimer inactive_timer;
669 
670 #ifdef CONFIG_RT_MUTEXES
671 	/*
672 	 * Priority Inheritance. When a DEADLINE scheduling entity is boosted
673 	 * pi_se points to the donor, otherwise points to the dl_se it belongs
674 	 * to (the original one/itself).
675 	 */
676 	struct sched_dl_entity *pi_se;
677 #endif
678 };
679 
680 #ifdef CONFIG_UCLAMP_TASK
681 /* Number of utilization clamp buckets (shorter alias) */
682 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT
683 
684 /*
685  * Utilization clamp for a scheduling entity
686  * @value:		clamp value "assigned" to a se
687  * @bucket_id:		bucket index corresponding to the "assigned" value
688  * @active:		the se is currently refcounted in a rq's bucket
689  * @user_defined:	the requested clamp value comes from user-space
690  *
691  * The bucket_id is the index of the clamp bucket matching the clamp value
692  * which is pre-computed and stored to avoid expensive integer divisions from
693  * the fast path.
694  *
695  * The active bit is set whenever a task has got an "effective" value assigned,
696  * which can be different from the clamp value "requested" from user-space.
697  * This allows to know a task is refcounted in the rq's bucket corresponding
698  * to the "effective" bucket_id.
699  *
700  * The user_defined bit is set whenever a task has got a task-specific clamp
701  * value requested from userspace, i.e. the system defaults apply to this task
702  * just as a restriction. This allows to relax default clamps when a less
703  * restrictive task-specific value has been requested, thus allowing to
704  * implement a "nice" semantic. For example, a task running with a 20%
705  * default boost can still drop its own boosting to 0%.
706  */
707 struct uclamp_se {
708 	unsigned int value		: bits_per(SCHED_CAPACITY_SCALE);
709 	unsigned int bucket_id		: bits_per(UCLAMP_BUCKETS);
710 	unsigned int active		: 1;
711 	unsigned int user_defined	: 1;
712 };
713 #endif /* CONFIG_UCLAMP_TASK */
714 
715 union rcu_special {
716 	struct {
717 		u8			blocked;
718 		u8			need_qs;
719 		u8			exp_hint; /* Hint for performance. */
720 		u8			need_mb; /* Readers need smp_mb(). */
721 	} b; /* Bits. */
722 	u32 s; /* Set of bits. */
723 };
724 
725 enum perf_event_task_context {
726 	perf_invalid_context = -1,
727 	perf_hw_context = 0,
728 	perf_sw_context,
729 	perf_nr_task_contexts,
730 };
731 
732 struct wake_q_node {
733 	struct wake_q_node *next;
734 };
735 
736 struct kmap_ctrl {
737 #ifdef CONFIG_KMAP_LOCAL
738 	int				idx;
739 	pte_t				pteval[KM_MAX_IDX];
740 #endif
741 };
742 
743 struct task_struct {
744 #ifdef CONFIG_THREAD_INFO_IN_TASK
745 	/*
746 	 * For reasons of header soup (see current_thread_info()), this
747 	 * must be the first element of task_struct.
748 	 */
749 	struct thread_info		thread_info;
750 #endif
751 	unsigned int			__state;
752 
753 #ifdef CONFIG_PREEMPT_RT
754 	/* saved state for "spinlock sleepers" */
755 	unsigned int			saved_state;
756 #endif
757 
758 	/*
759 	 * This begins the randomizable portion of task_struct. Only
760 	 * scheduling-critical items should be added above here.
761 	 */
762 	randomized_struct_fields_start
763 
764 	void				*stack;
765 	refcount_t			usage;
766 	/* Per task flags (PF_*), defined further below: */
767 	unsigned int			flags;
768 	unsigned int			ptrace;
769 
770 #ifdef CONFIG_SMP
771 	int				on_cpu;
772 	struct __call_single_node	wake_entry;
773 	unsigned int			wakee_flips;
774 	unsigned long			wakee_flip_decay_ts;
775 	struct task_struct		*last_wakee;
776 
777 	/*
778 	 * recent_used_cpu is initially set as the last CPU used by a task
779 	 * that wakes affine another task. Waker/wakee relationships can
780 	 * push tasks around a CPU where each wakeup moves to the next one.
781 	 * Tracking a recently used CPU allows a quick search for a recently
782 	 * used CPU that may be idle.
783 	 */
784 	int				recent_used_cpu;
785 	int				wake_cpu;
786 #endif
787 	int				on_rq;
788 
789 	int				prio;
790 	int				static_prio;
791 	int				normal_prio;
792 	unsigned int			rt_priority;
793 
794 	struct sched_entity		se;
795 	struct sched_rt_entity		rt;
796 	struct sched_dl_entity		dl;
797 	const struct sched_class	*sched_class;
798 
799 #ifdef CONFIG_SCHED_CORE
800 	struct rb_node			core_node;
801 	unsigned long			core_cookie;
802 	unsigned int			core_occupation;
803 #endif
804 
805 #ifdef CONFIG_CGROUP_SCHED
806 	struct task_group		*sched_task_group;
807 #endif
808 
809 #ifdef CONFIG_UCLAMP_TASK
810 	/*
811 	 * Clamp values requested for a scheduling entity.
812 	 * Must be updated with task_rq_lock() held.
813 	 */
814 	struct uclamp_se		uclamp_req[UCLAMP_CNT];
815 	/*
816 	 * Effective clamp values used for a scheduling entity.
817 	 * Must be updated with task_rq_lock() held.
818 	 */
819 	struct uclamp_se		uclamp[UCLAMP_CNT];
820 #endif
821 
822 	struct sched_statistics         stats;
823 
824 #ifdef CONFIG_PREEMPT_NOTIFIERS
825 	/* List of struct preempt_notifier: */
826 	struct hlist_head		preempt_notifiers;
827 #endif
828 
829 #ifdef CONFIG_BLK_DEV_IO_TRACE
830 	unsigned int			btrace_seq;
831 #endif
832 
833 	unsigned int			policy;
834 	int				nr_cpus_allowed;
835 	const cpumask_t			*cpus_ptr;
836 	cpumask_t			*user_cpus_ptr;
837 	cpumask_t			cpus_mask;
838 	void				*migration_pending;
839 #ifdef CONFIG_SMP
840 	unsigned short			migration_disabled;
841 #endif
842 	unsigned short			migration_flags;
843 
844 #ifdef CONFIG_PREEMPT_RCU
845 	int				rcu_read_lock_nesting;
846 	union rcu_special		rcu_read_unlock_special;
847 	struct list_head		rcu_node_entry;
848 	struct rcu_node			*rcu_blocked_node;
849 #endif /* #ifdef CONFIG_PREEMPT_RCU */
850 
851 #ifdef CONFIG_TASKS_RCU
852 	unsigned long			rcu_tasks_nvcsw;
853 	u8				rcu_tasks_holdout;
854 	u8				rcu_tasks_idx;
855 	int				rcu_tasks_idle_cpu;
856 	struct list_head		rcu_tasks_holdout_list;
857 #endif /* #ifdef CONFIG_TASKS_RCU */
858 
859 #ifdef CONFIG_TASKS_TRACE_RCU
860 	int				trc_reader_nesting;
861 	int				trc_ipi_to_cpu;
862 	union rcu_special		trc_reader_special;
863 	struct list_head		trc_holdout_list;
864 	struct list_head		trc_blkd_node;
865 	int				trc_blkd_cpu;
866 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
867 
868 	struct sched_info		sched_info;
869 
870 	struct list_head		tasks;
871 #ifdef CONFIG_SMP
872 	struct plist_node		pushable_tasks;
873 	struct rb_node			pushable_dl_tasks;
874 #endif
875 
876 	struct mm_struct		*mm;
877 	struct mm_struct		*active_mm;
878 
879 	int				exit_state;
880 	int				exit_code;
881 	int				exit_signal;
882 	/* The signal sent when the parent dies: */
883 	int				pdeath_signal;
884 	/* JOBCTL_*, siglock protected: */
885 	unsigned long			jobctl;
886 
887 	/* Used for emulating ABI behavior of previous Linux versions: */
888 	unsigned int			personality;
889 
890 	/* Scheduler bits, serialized by scheduler locks: */
891 	unsigned			sched_reset_on_fork:1;
892 	unsigned			sched_contributes_to_load:1;
893 	unsigned			sched_migrated:1;
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 #ifdef CONFIG_IOMMU_SVA
953 	unsigned			pasid_activated:1;
954 #endif
955 #ifdef	CONFIG_CPU_SUP_INTEL
956 	unsigned			reported_split_lock:1;
957 #endif
958 #ifdef CONFIG_TASK_DELAY_ACCT
959 	/* delay due to memory thrashing */
960 	unsigned                        in_thrashing:1;
961 #endif
962 
963 	unsigned long			atomic_flags; /* Flags requiring atomic access. */
964 
965 	struct restart_block		restart_block;
966 
967 	pid_t				pid;
968 	pid_t				tgid;
969 
970 #ifdef CONFIG_STACKPROTECTOR
971 	/* Canary value for the -fstack-protector GCC feature: */
972 	unsigned long			stack_canary;
973 #endif
974 	/*
975 	 * Pointers to the (original) parent process, youngest child, younger sibling,
976 	 * older sibling, respectively.  (p->father can be replaced with
977 	 * p->real_parent->pid)
978 	 */
979 
980 	/* Real parent process: */
981 	struct task_struct __rcu	*real_parent;
982 
983 	/* Recipient of SIGCHLD, wait4() reports: */
984 	struct task_struct __rcu	*parent;
985 
986 	/*
987 	 * Children/sibling form the list of natural children:
988 	 */
989 	struct list_head		children;
990 	struct list_head		sibling;
991 	struct task_struct		*group_leader;
992 
993 	/*
994 	 * 'ptraced' is the list of tasks this task is using ptrace() on.
995 	 *
996 	 * This includes both natural children and PTRACE_ATTACH targets.
997 	 * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
998 	 */
999 	struct list_head		ptraced;
1000 	struct list_head		ptrace_entry;
1001 
1002 	/* PID/PID hash table linkage. */
1003 	struct pid			*thread_pid;
1004 	struct hlist_node		pid_links[PIDTYPE_MAX];
1005 	struct list_head		thread_group;
1006 	struct list_head		thread_node;
1007 
1008 	struct completion		*vfork_done;
1009 
1010 	/* CLONE_CHILD_SETTID: */
1011 	int __user			*set_child_tid;
1012 
1013 	/* CLONE_CHILD_CLEARTID: */
1014 	int __user			*clear_child_tid;
1015 
1016 	/* PF_KTHREAD | PF_IO_WORKER */
1017 	void				*worker_private;
1018 
1019 	u64				utime;
1020 	u64				stime;
1021 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
1022 	u64				utimescaled;
1023 	u64				stimescaled;
1024 #endif
1025 	u64				gtime;
1026 	struct prev_cputime		prev_cputime;
1027 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1028 	struct vtime			vtime;
1029 #endif
1030 
1031 #ifdef CONFIG_NO_HZ_FULL
1032 	atomic_t			tick_dep_mask;
1033 #endif
1034 	/* Context switch counts: */
1035 	unsigned long			nvcsw;
1036 	unsigned long			nivcsw;
1037 
1038 	/* Monotonic time in nsecs: */
1039 	u64				start_time;
1040 
1041 	/* Boot based time in nsecs: */
1042 	u64				start_boottime;
1043 
1044 	/* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
1045 	unsigned long			min_flt;
1046 	unsigned long			maj_flt;
1047 
1048 	/* Empty if CONFIG_POSIX_CPUTIMERS=n */
1049 	struct posix_cputimers		posix_cputimers;
1050 
1051 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK
1052 	struct posix_cputimers_work	posix_cputimers_work;
1053 #endif
1054 
1055 	/* Process credentials: */
1056 
1057 	/* Tracer's credentials at attach: */
1058 	const struct cred __rcu		*ptracer_cred;
1059 
1060 	/* Objective and real subjective task credentials (COW): */
1061 	const struct cred __rcu		*real_cred;
1062 
1063 	/* Effective (overridable) subjective task credentials (COW): */
1064 	const struct cred __rcu		*cred;
1065 
1066 #ifdef CONFIG_KEYS
1067 	/* Cached requested key. */
1068 	struct key			*cached_requested_key;
1069 #endif
1070 
1071 	/*
1072 	 * executable name, excluding path.
1073 	 *
1074 	 * - normally initialized setup_new_exec()
1075 	 * - access it with [gs]et_task_comm()
1076 	 * - lock it with task_lock()
1077 	 */
1078 	char				comm[TASK_COMM_LEN];
1079 
1080 	struct nameidata		*nameidata;
1081 
1082 #ifdef CONFIG_SYSVIPC
1083 	struct sysv_sem			sysvsem;
1084 	struct sysv_shm			sysvshm;
1085 #endif
1086 #ifdef CONFIG_DETECT_HUNG_TASK
1087 	unsigned long			last_switch_count;
1088 	unsigned long			last_switch_time;
1089 #endif
1090 	/* Filesystem information: */
1091 	struct fs_struct		*fs;
1092 
1093 	/* Open file information: */
1094 	struct files_struct		*files;
1095 
1096 #ifdef CONFIG_IO_URING
1097 	struct io_uring_task		*io_uring;
1098 #endif
1099 
1100 	/* Namespaces: */
1101 	struct nsproxy			*nsproxy;
1102 
1103 	/* Signal handlers: */
1104 	struct signal_struct		*signal;
1105 	struct sighand_struct __rcu		*sighand;
1106 	sigset_t			blocked;
1107 	sigset_t			real_blocked;
1108 	/* Restored if set_restore_sigmask() was used: */
1109 	sigset_t			saved_sigmask;
1110 	struct sigpending		pending;
1111 	unsigned long			sas_ss_sp;
1112 	size_t				sas_ss_size;
1113 	unsigned int			sas_ss_flags;
1114 
1115 	struct callback_head		*task_works;
1116 
1117 #ifdef CONFIG_AUDIT
1118 #ifdef CONFIG_AUDITSYSCALL
1119 	struct audit_context		*audit_context;
1120 #endif
1121 	kuid_t				loginuid;
1122 	unsigned int			sessionid;
1123 #endif
1124 	struct seccomp			seccomp;
1125 	struct syscall_user_dispatch	syscall_dispatch;
1126 
1127 	/* Thread group tracking: */
1128 	u64				parent_exec_id;
1129 	u64				self_exec_id;
1130 
1131 	/* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
1132 	spinlock_t			alloc_lock;
1133 
1134 	/* Protection of the PI data structures: */
1135 	raw_spinlock_t			pi_lock;
1136 
1137 	struct wake_q_node		wake_q;
1138 
1139 #ifdef CONFIG_RT_MUTEXES
1140 	/* PI waiters blocked on a rt_mutex held by this task: */
1141 	struct rb_root_cached		pi_waiters;
1142 	/* Updated under owner's pi_lock and rq lock */
1143 	struct task_struct		*pi_top_task;
1144 	/* Deadlock detection and priority inheritance handling: */
1145 	struct rt_mutex_waiter		*pi_blocked_on;
1146 #endif
1147 
1148 #ifdef CONFIG_DEBUG_MUTEXES
1149 	/* Mutex deadlock detection: */
1150 	struct mutex_waiter		*blocked_on;
1151 #endif
1152 
1153 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1154 	int				non_block_count;
1155 #endif
1156 
1157 #ifdef CONFIG_TRACE_IRQFLAGS
1158 	struct irqtrace_events		irqtrace;
1159 	unsigned int			hardirq_threaded;
1160 	u64				hardirq_chain_key;
1161 	int				softirqs_enabled;
1162 	int				softirq_context;
1163 	int				irq_config;
1164 #endif
1165 #ifdef CONFIG_PREEMPT_RT
1166 	int				softirq_disable_cnt;
1167 #endif
1168 
1169 #ifdef CONFIG_LOCKDEP
1170 # define MAX_LOCK_DEPTH			48UL
1171 	u64				curr_chain_key;
1172 	int				lockdep_depth;
1173 	unsigned int			lockdep_recursion;
1174 	struct held_lock		held_locks[MAX_LOCK_DEPTH];
1175 #endif
1176 
1177 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP)
1178 	unsigned int			in_ubsan;
1179 #endif
1180 
1181 	/* Journalling filesystem info: */
1182 	void				*journal_info;
1183 
1184 	/* Stacked block device info: */
1185 	struct bio_list			*bio_list;
1186 
1187 	/* Stack plugging: */
1188 	struct blk_plug			*plug;
1189 
1190 	/* VM state: */
1191 	struct reclaim_state		*reclaim_state;
1192 
1193 	struct io_context		*io_context;
1194 
1195 #ifdef CONFIG_COMPACTION
1196 	struct capture_control		*capture_control;
1197 #endif
1198 	/* Ptrace state: */
1199 	unsigned long			ptrace_message;
1200 	kernel_siginfo_t		*last_siginfo;
1201 
1202 	struct task_io_accounting	ioac;
1203 #ifdef CONFIG_PSI
1204 	/* Pressure stall state */
1205 	unsigned int			psi_flags;
1206 #endif
1207 #ifdef CONFIG_TASK_XACCT
1208 	/* Accumulated RSS usage: */
1209 	u64				acct_rss_mem1;
1210 	/* Accumulated virtual memory usage: */
1211 	u64				acct_vm_mem1;
1212 	/* stime + utime since last update: */
1213 	u64				acct_timexpd;
1214 #endif
1215 #ifdef CONFIG_CPUSETS
1216 	/* Protected by ->alloc_lock: */
1217 	nodemask_t			mems_allowed;
1218 	/* Sequence number to catch updates: */
1219 	seqcount_spinlock_t		mems_allowed_seq;
1220 	int				cpuset_mem_spread_rotor;
1221 	int				cpuset_slab_spread_rotor;
1222 #endif
1223 #ifdef CONFIG_CGROUPS
1224 	/* Control Group info protected by css_set_lock: */
1225 	struct css_set __rcu		*cgroups;
1226 	/* cg_list protected by css_set_lock and tsk->alloc_lock: */
1227 	struct list_head		cg_list;
1228 #endif
1229 #ifdef CONFIG_X86_CPU_RESCTRL
1230 	u32				closid;
1231 	u32				rmid;
1232 #endif
1233 #ifdef CONFIG_FUTEX
1234 	struct robust_list_head __user	*robust_list;
1235 #ifdef CONFIG_COMPAT
1236 	struct compat_robust_list_head __user *compat_robust_list;
1237 #endif
1238 	struct list_head		pi_state_list;
1239 	struct futex_pi_state		*pi_state_cache;
1240 	struct mutex			futex_exit_mutex;
1241 	unsigned int			futex_state;
1242 #endif
1243 #ifdef CONFIG_PERF_EVENTS
1244 	struct perf_event_context	*perf_event_ctxp;
1245 	struct mutex			perf_event_mutex;
1246 	struct list_head		perf_event_list;
1247 #endif
1248 #ifdef CONFIG_DEBUG_PREEMPT
1249 	unsigned long			preempt_disable_ip;
1250 #endif
1251 #ifdef CONFIG_NUMA
1252 	/* Protected by alloc_lock: */
1253 	struct mempolicy		*mempolicy;
1254 	short				il_prev;
1255 	short				pref_node_fork;
1256 #endif
1257 #ifdef CONFIG_NUMA_BALANCING
1258 	int				numa_scan_seq;
1259 	unsigned int			numa_scan_period;
1260 	unsigned int			numa_scan_period_max;
1261 	int				numa_preferred_nid;
1262 	unsigned long			numa_migrate_retry;
1263 	/* Migration stamp: */
1264 	u64				node_stamp;
1265 	u64				last_task_numa_placement;
1266 	u64				last_sum_exec_runtime;
1267 	struct callback_head		numa_work;
1268 
1269 	/*
1270 	 * This pointer is only modified for current in syscall and
1271 	 * pagefault context (and for tasks being destroyed), so it can be read
1272 	 * from any of the following contexts:
1273 	 *  - RCU read-side critical section
1274 	 *  - current->numa_group from everywhere
1275 	 *  - task's runqueue locked, task not running
1276 	 */
1277 	struct numa_group __rcu		*numa_group;
1278 
1279 	/*
1280 	 * numa_faults is an array split into four regions:
1281 	 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1282 	 * in this precise order.
1283 	 *
1284 	 * faults_memory: Exponential decaying average of faults on a per-node
1285 	 * basis. Scheduling placement decisions are made based on these
1286 	 * counts. The values remain static for the duration of a PTE scan.
1287 	 * faults_cpu: Track the nodes the process was running on when a NUMA
1288 	 * hinting fault was incurred.
1289 	 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1290 	 * during the current scan window. When the scan completes, the counts
1291 	 * in faults_memory and faults_cpu decay and these values are copied.
1292 	 */
1293 	unsigned long			*numa_faults;
1294 	unsigned long			total_numa_faults;
1295 
1296 	/*
1297 	 * numa_faults_locality tracks if faults recorded during the last
1298 	 * scan window were remote/local or failed to migrate. The task scan
1299 	 * period is adapted based on the locality of the faults with different
1300 	 * weights depending on whether they were shared or private faults
1301 	 */
1302 	unsigned long			numa_faults_locality[3];
1303 
1304 	unsigned long			numa_pages_migrated;
1305 #endif /* CONFIG_NUMA_BALANCING */
1306 
1307 #ifdef CONFIG_RSEQ
1308 	struct rseq __user *rseq;
1309 	u32 rseq_len;
1310 	u32 rseq_sig;
1311 	/*
1312 	 * RmW on rseq_event_mask must be performed atomically
1313 	 * with respect to preemption.
1314 	 */
1315 	unsigned long rseq_event_mask;
1316 #endif
1317 
1318 #ifdef CONFIG_SCHED_MM_CID
1319 	int				mm_cid;		/* Current cid in mm */
1320 	int				last_mm_cid;	/* Most recent cid in mm */
1321 	int				migrate_from_cpu;
1322 	int				mm_cid_active;	/* Whether cid bitmap is active */
1323 	struct callback_head		cid_work;
1324 #endif
1325 
1326 	struct tlbflush_unmap_batch	tlb_ubc;
1327 
1328 	/* Cache last used pipe for splice(): */
1329 	struct pipe_inode_info		*splice_pipe;
1330 
1331 	struct page_frag		task_frag;
1332 
1333 #ifdef CONFIG_TASK_DELAY_ACCT
1334 	struct task_delay_info		*delays;
1335 #endif
1336 
1337 #ifdef CONFIG_FAULT_INJECTION
1338 	int				make_it_fail;
1339 	unsigned int			fail_nth;
1340 #endif
1341 	/*
1342 	 * When (nr_dirtied >= nr_dirtied_pause), it's time to call
1343 	 * balance_dirty_pages() for a dirty throttling pause:
1344 	 */
1345 	int				nr_dirtied;
1346 	int				nr_dirtied_pause;
1347 	/* Start of a write-and-pause period: */
1348 	unsigned long			dirty_paused_when;
1349 
1350 #ifdef CONFIG_LATENCYTOP
1351 	int				latency_record_count;
1352 	struct latency_record		latency_record[LT_SAVECOUNT];
1353 #endif
1354 	/*
1355 	 * Time slack values; these are used to round up poll() and
1356 	 * select() etc timeout values. These are in nanoseconds.
1357 	 */
1358 	u64				timer_slack_ns;
1359 	u64				default_timer_slack_ns;
1360 
1361 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
1362 	unsigned int			kasan_depth;
1363 #endif
1364 
1365 #ifdef CONFIG_KCSAN
1366 	struct kcsan_ctx		kcsan_ctx;
1367 #ifdef CONFIG_TRACE_IRQFLAGS
1368 	struct irqtrace_events		kcsan_save_irqtrace;
1369 #endif
1370 #ifdef CONFIG_KCSAN_WEAK_MEMORY
1371 	int				kcsan_stack_depth;
1372 #endif
1373 #endif
1374 
1375 #ifdef CONFIG_KMSAN
1376 	struct kmsan_ctx		kmsan_ctx;
1377 #endif
1378 
1379 #if IS_ENABLED(CONFIG_KUNIT)
1380 	struct kunit			*kunit_test;
1381 #endif
1382 
1383 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1384 	/* Index of current stored address in ret_stack: */
1385 	int				curr_ret_stack;
1386 	int				curr_ret_depth;
1387 
1388 	/* Stack of return addresses for return function tracing: */
1389 	struct ftrace_ret_stack		*ret_stack;
1390 
1391 	/* Timestamp for last schedule: */
1392 	unsigned long long		ftrace_timestamp;
1393 
1394 	/*
1395 	 * Number of functions that haven't been traced
1396 	 * because of depth overrun:
1397 	 */
1398 	atomic_t			trace_overrun;
1399 
1400 	/* Pause tracing: */
1401 	atomic_t			tracing_graph_pause;
1402 #endif
1403 
1404 #ifdef CONFIG_TRACING
1405 	/* Bitmask and counter of trace recursion: */
1406 	unsigned long			trace_recursion;
1407 #endif /* CONFIG_TRACING */
1408 
1409 #ifdef CONFIG_KCOV
1410 	/* See kernel/kcov.c for more details. */
1411 
1412 	/* Coverage collection mode enabled for this task (0 if disabled): */
1413 	unsigned int			kcov_mode;
1414 
1415 	/* Size of the kcov_area: */
1416 	unsigned int			kcov_size;
1417 
1418 	/* Buffer for coverage collection: */
1419 	void				*kcov_area;
1420 
1421 	/* KCOV descriptor wired with this task or NULL: */
1422 	struct kcov			*kcov;
1423 
1424 	/* KCOV common handle for remote coverage collection: */
1425 	u64				kcov_handle;
1426 
1427 	/* KCOV sequence number: */
1428 	int				kcov_sequence;
1429 
1430 	/* Collect coverage from softirq context: */
1431 	unsigned int			kcov_softirq;
1432 #endif
1433 
1434 #ifdef CONFIG_MEMCG
1435 	struct mem_cgroup		*memcg_in_oom;
1436 	gfp_t				memcg_oom_gfp_mask;
1437 	int				memcg_oom_order;
1438 
1439 	/* Number of pages to reclaim on returning to userland: */
1440 	unsigned int			memcg_nr_pages_over_high;
1441 
1442 	/* Used by memcontrol for targeted memcg charge: */
1443 	struct mem_cgroup		*active_memcg;
1444 #endif
1445 
1446 #ifdef CONFIG_BLK_CGROUP
1447 	struct gendisk			*throttle_disk;
1448 #endif
1449 
1450 #ifdef CONFIG_UPROBES
1451 	struct uprobe_task		*utask;
1452 #endif
1453 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1454 	unsigned int			sequential_io;
1455 	unsigned int			sequential_io_avg;
1456 #endif
1457 	struct kmap_ctrl		kmap_ctrl;
1458 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1459 	unsigned long			task_state_change;
1460 # ifdef CONFIG_PREEMPT_RT
1461 	unsigned long			saved_state_change;
1462 # endif
1463 #endif
1464 	struct rcu_head			rcu;
1465 	refcount_t			rcu_users;
1466 	int				pagefault_disabled;
1467 #ifdef CONFIG_MMU
1468 	struct task_struct		*oom_reaper_list;
1469 	struct timer_list		oom_reaper_timer;
1470 #endif
1471 #ifdef CONFIG_VMAP_STACK
1472 	struct vm_struct		*stack_vm_area;
1473 #endif
1474 #ifdef CONFIG_THREAD_INFO_IN_TASK
1475 	/* A live task holds one reference: */
1476 	refcount_t			stack_refcount;
1477 #endif
1478 #ifdef CONFIG_LIVEPATCH
1479 	int patch_state;
1480 #endif
1481 #ifdef CONFIG_SECURITY
1482 	/* Used by LSM modules for access restriction: */
1483 	void				*security;
1484 #endif
1485 #ifdef CONFIG_BPF_SYSCALL
1486 	/* Used by BPF task local storage */
1487 	struct bpf_local_storage __rcu	*bpf_storage;
1488 	/* Used for BPF run context */
1489 	struct bpf_run_ctx		*bpf_ctx;
1490 #endif
1491 
1492 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK
1493 	unsigned long			lowest_stack;
1494 	unsigned long			prev_lowest_stack;
1495 #endif
1496 
1497 #ifdef CONFIG_X86_MCE
1498 	void __user			*mce_vaddr;
1499 	__u64				mce_kflags;
1500 	u64				mce_addr;
1501 	__u64				mce_ripv : 1,
1502 					mce_whole_page : 1,
1503 					__mce_reserved : 62;
1504 	struct callback_head		mce_kill_me;
1505 	int				mce_count;
1506 #endif
1507 
1508 #ifdef CONFIG_KRETPROBES
1509 	struct llist_head               kretprobe_instances;
1510 #endif
1511 #ifdef CONFIG_RETHOOK
1512 	struct llist_head               rethooks;
1513 #endif
1514 
1515 #ifdef CONFIG_ARCH_HAS_PARANOID_L1D_FLUSH
1516 	/*
1517 	 * If L1D flush is supported on mm context switch
1518 	 * then we use this callback head to queue kill work
1519 	 * to kill tasks that are not running on SMT disabled
1520 	 * cores
1521 	 */
1522 	struct callback_head		l1d_flush_kill;
1523 #endif
1524 
1525 #ifdef CONFIG_RV
1526 	/*
1527 	 * Per-task RV monitor. Nowadays fixed in RV_PER_TASK_MONITORS.
1528 	 * If we find justification for more monitors, we can think
1529 	 * about adding more or developing a dynamic method. So far,
1530 	 * none of these are justified.
1531 	 */
1532 	union rv_task_monitor		rv[RV_PER_TASK_MONITORS];
1533 #endif
1534 
1535 #ifdef CONFIG_USER_EVENTS
1536 	struct user_event_mm		*user_event_mm;
1537 #endif
1538 
1539 	/*
1540 	 * New fields for task_struct should be added above here, so that
1541 	 * they are included in the randomized portion of task_struct.
1542 	 */
1543 	randomized_struct_fields_end
1544 
1545 	/* CPU-specific state of this task: */
1546 	struct thread_struct		thread;
1547 
1548 	/*
1549 	 * WARNING: on x86, 'thread_struct' contains a variable-sized
1550 	 * structure.  It *MUST* be at the end of 'task_struct'.
1551 	 *
1552 	 * Do not put anything below here!
1553 	 */
1554 };
1555 
task_pid(struct task_struct * task)1556 static inline struct pid *task_pid(struct task_struct *task)
1557 {
1558 	return task->thread_pid;
1559 }
1560 
1561 /*
1562  * the helpers to get the task's different pids as they are seen
1563  * from various namespaces
1564  *
1565  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1566  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1567  *                     current.
1568  * task_xid_nr_ns()  : id seen from the ns specified;
1569  *
1570  * see also pid_nr() etc in include/linux/pid.h
1571  */
1572 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns);
1573 
task_pid_nr(struct task_struct * tsk)1574 static inline pid_t task_pid_nr(struct task_struct *tsk)
1575 {
1576 	return tsk->pid;
1577 }
1578 
task_pid_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1579 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1580 {
1581 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1582 }
1583 
task_pid_vnr(struct task_struct * tsk)1584 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1585 {
1586 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1587 }
1588 
1589 
task_tgid_nr(struct task_struct * tsk)1590 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1591 {
1592 	return tsk->tgid;
1593 }
1594 
1595 /**
1596  * pid_alive - check that a task structure is not stale
1597  * @p: Task structure to be checked.
1598  *
1599  * Test if a process is not yet dead (at most zombie state)
1600  * If pid_alive fails, then pointers within the task structure
1601  * can be stale and must not be dereferenced.
1602  *
1603  * Return: 1 if the process is alive. 0 otherwise.
1604  */
pid_alive(const struct task_struct * p)1605 static inline int pid_alive(const struct task_struct *p)
1606 {
1607 	return p->thread_pid != NULL;
1608 }
1609 
task_pgrp_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1610 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1611 {
1612 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1613 }
1614 
task_pgrp_vnr(struct task_struct * tsk)1615 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1616 {
1617 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1618 }
1619 
1620 
task_session_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1621 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1622 {
1623 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1624 }
1625 
task_session_vnr(struct task_struct * tsk)1626 static inline pid_t task_session_vnr(struct task_struct *tsk)
1627 {
1628 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1629 }
1630 
task_tgid_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1631 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1632 {
1633 	return __task_pid_nr_ns(tsk, PIDTYPE_TGID, ns);
1634 }
1635 
task_tgid_vnr(struct task_struct * tsk)1636 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1637 {
1638 	return __task_pid_nr_ns(tsk, PIDTYPE_TGID, NULL);
1639 }
1640 
task_ppid_nr_ns(const struct task_struct * tsk,struct pid_namespace * ns)1641 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1642 {
1643 	pid_t pid = 0;
1644 
1645 	rcu_read_lock();
1646 	if (pid_alive(tsk))
1647 		pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1648 	rcu_read_unlock();
1649 
1650 	return pid;
1651 }
1652 
task_ppid_nr(const struct task_struct * tsk)1653 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1654 {
1655 	return task_ppid_nr_ns(tsk, &init_pid_ns);
1656 }
1657 
1658 /* Obsolete, do not use: */
task_pgrp_nr(struct task_struct * tsk)1659 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1660 {
1661 	return task_pgrp_nr_ns(tsk, &init_pid_ns);
1662 }
1663 
1664 #define TASK_REPORT_IDLE	(TASK_REPORT + 1)
1665 #define TASK_REPORT_MAX		(TASK_REPORT_IDLE << 1)
1666 
__task_state_index(unsigned int tsk_state,unsigned int tsk_exit_state)1667 static inline unsigned int __task_state_index(unsigned int tsk_state,
1668 					      unsigned int tsk_exit_state)
1669 {
1670 	unsigned int state = (tsk_state | tsk_exit_state) & TASK_REPORT;
1671 
1672 	BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX);
1673 
1674 	if ((tsk_state & TASK_IDLE) == TASK_IDLE)
1675 		state = TASK_REPORT_IDLE;
1676 
1677 	/*
1678 	 * We're lying here, but rather than expose a completely new task state
1679 	 * to userspace, we can make this appear as if the task has gone through
1680 	 * a regular rt_mutex_lock() call.
1681 	 */
1682 	if (tsk_state & TASK_RTLOCK_WAIT)
1683 		state = TASK_UNINTERRUPTIBLE;
1684 
1685 	return fls(state);
1686 }
1687 
task_state_index(struct task_struct * tsk)1688 static inline unsigned int task_state_index(struct task_struct *tsk)
1689 {
1690 	return __task_state_index(READ_ONCE(tsk->__state), tsk->exit_state);
1691 }
1692 
task_index_to_char(unsigned int state)1693 static inline char task_index_to_char(unsigned int state)
1694 {
1695 	static const char state_char[] = "RSDTtXZPI";
1696 
1697 	BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1);
1698 
1699 	return state_char[state];
1700 }
1701 
task_state_to_char(struct task_struct * tsk)1702 static inline char task_state_to_char(struct task_struct *tsk)
1703 {
1704 	return task_index_to_char(task_state_index(tsk));
1705 }
1706 
1707 /**
1708  * is_global_init - check if a task structure is init. Since init
1709  * is free to have sub-threads we need to check tgid.
1710  * @tsk: Task structure to be checked.
1711  *
1712  * Check if a task structure is the first user space task the kernel created.
1713  *
1714  * Return: 1 if the task structure is init. 0 otherwise.
1715  */
is_global_init(struct task_struct * tsk)1716 static inline int is_global_init(struct task_struct *tsk)
1717 {
1718 	return task_tgid_nr(tsk) == 1;
1719 }
1720 
1721 extern struct pid *cad_pid;
1722 
1723 /*
1724  * Per process flags
1725  */
1726 #define PF_VCPU			0x00000001	/* I'm a virtual CPU */
1727 #define PF_IDLE			0x00000002	/* I am an IDLE thread */
1728 #define PF_EXITING		0x00000004	/* Getting shut down */
1729 #define PF_POSTCOREDUMP		0x00000008	/* Coredumps should ignore this task */
1730 #define PF_IO_WORKER		0x00000010	/* Task is an IO worker */
1731 #define PF_WQ_WORKER		0x00000020	/* I'm a workqueue worker */
1732 #define PF_FORKNOEXEC		0x00000040	/* Forked but didn't exec */
1733 #define PF_MCE_PROCESS		0x00000080      /* Process policy on mce errors */
1734 #define PF_SUPERPRIV		0x00000100	/* Used super-user privileges */
1735 #define PF_DUMPCORE		0x00000200	/* Dumped core */
1736 #define PF_SIGNALED		0x00000400	/* Killed by a signal */
1737 #define PF_MEMALLOC		0x00000800	/* Allocating memory */
1738 #define PF_NPROC_EXCEEDED	0x00001000	/* set_user() noticed that RLIMIT_NPROC was exceeded */
1739 #define PF_USED_MATH		0x00002000	/* If unset the fpu must be initialized before use */
1740 #define PF_USER_WORKER		0x00004000	/* Kernel thread cloned from userspace thread */
1741 #define PF_NOFREEZE		0x00008000	/* This thread should not be frozen */
1742 #define PF__HOLE__00010000	0x00010000
1743 #define PF_KSWAPD		0x00020000	/* I am kswapd */
1744 #define PF_MEMALLOC_NOFS	0x00040000	/* All allocation requests will inherit GFP_NOFS */
1745 #define PF_MEMALLOC_NOIO	0x00080000	/* All allocation requests will inherit GFP_NOIO */
1746 #define PF_LOCAL_THROTTLE	0x00100000	/* Throttle writes only against the bdi I write to,
1747 						 * I am cleaning dirty pages from some other bdi. */
1748 #define PF_KTHREAD		0x00200000	/* I am a kernel thread */
1749 #define PF_RANDOMIZE		0x00400000	/* Randomize virtual address space */
1750 #define PF__HOLE__00800000	0x00800000
1751 #define PF__HOLE__01000000	0x01000000
1752 #define PF__HOLE__02000000	0x02000000
1753 #define PF_NO_SETAFFINITY	0x04000000	/* Userland is not allowed to meddle with cpus_mask */
1754 #define PF_MCE_EARLY		0x08000000      /* Early kill for mce process policy */
1755 #define PF_MEMALLOC_PIN		0x10000000	/* Allocation context constrained to zones which allow long term pinning. */
1756 #define PF__HOLE__20000000	0x20000000
1757 #define PF__HOLE__40000000	0x40000000
1758 #define PF_SUSPEND_TASK		0x80000000      /* This thread called freeze_processes() and should not be frozen */
1759 
1760 /*
1761  * Only the _current_ task can read/write to tsk->flags, but other
1762  * tasks can access tsk->flags in readonly mode for example
1763  * with tsk_used_math (like during threaded core dumping).
1764  * There is however an exception to this rule during ptrace
1765  * or during fork: the ptracer task is allowed to write to the
1766  * child->flags of its traced child (same goes for fork, the parent
1767  * can write to the child->flags), because we're guaranteed the
1768  * child is not running and in turn not changing child->flags
1769  * at the same time the parent does it.
1770  */
1771 #define clear_stopped_child_used_math(child)	do { (child)->flags &= ~PF_USED_MATH; } while (0)
1772 #define set_stopped_child_used_math(child)	do { (child)->flags |= PF_USED_MATH; } while (0)
1773 #define clear_used_math()			clear_stopped_child_used_math(current)
1774 #define set_used_math()				set_stopped_child_used_math(current)
1775 
1776 #define conditional_stopped_child_used_math(condition, child) \
1777 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1778 
1779 #define conditional_used_math(condition)	conditional_stopped_child_used_math(condition, current)
1780 
1781 #define copy_to_stopped_child_used_math(child) \
1782 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1783 
1784 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1785 #define tsk_used_math(p)			((p)->flags & PF_USED_MATH)
1786 #define used_math()				tsk_used_math(current)
1787 
is_percpu_thread(void)1788 static __always_inline bool is_percpu_thread(void)
1789 {
1790 #ifdef CONFIG_SMP
1791 	return (current->flags & PF_NO_SETAFFINITY) &&
1792 		(current->nr_cpus_allowed  == 1);
1793 #else
1794 	return true;
1795 #endif
1796 }
1797 
1798 /* Per-process atomic flags. */
1799 #define PFA_NO_NEW_PRIVS		0	/* May not gain new privileges. */
1800 #define PFA_SPREAD_PAGE			1	/* Spread page cache over cpuset */
1801 #define PFA_SPREAD_SLAB			2	/* Spread some slab caches over cpuset */
1802 #define PFA_SPEC_SSB_DISABLE		3	/* Speculative Store Bypass disabled */
1803 #define PFA_SPEC_SSB_FORCE_DISABLE	4	/* Speculative Store Bypass force disabled*/
1804 #define PFA_SPEC_IB_DISABLE		5	/* Indirect branch speculation restricted */
1805 #define PFA_SPEC_IB_FORCE_DISABLE	6	/* Indirect branch speculation permanently restricted */
1806 #define PFA_SPEC_SSB_NOEXEC		7	/* Speculative Store Bypass clear on execve() */
1807 
1808 #define TASK_PFA_TEST(name, func)					\
1809 	static inline bool task_##func(struct task_struct *p)		\
1810 	{ return test_bit(PFA_##name, &p->atomic_flags); }
1811 
1812 #define TASK_PFA_SET(name, func)					\
1813 	static inline void task_set_##func(struct task_struct *p)	\
1814 	{ set_bit(PFA_##name, &p->atomic_flags); }
1815 
1816 #define TASK_PFA_CLEAR(name, func)					\
1817 	static inline void task_clear_##func(struct task_struct *p)	\
1818 	{ clear_bit(PFA_##name, &p->atomic_flags); }
1819 
TASK_PFA_TEST(NO_NEW_PRIVS,no_new_privs)1820 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
1821 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
1822 
1823 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
1824 TASK_PFA_SET(SPREAD_PAGE, spread_page)
1825 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
1826 
1827 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
1828 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
1829 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
1830 
1831 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable)
1832 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable)
1833 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable)
1834 
1835 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1836 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1837 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1838 
1839 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1840 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1841 
1842 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable)
1843 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable)
1844 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable)
1845 
1846 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1847 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1848 
1849 static inline void
1850 current_restore_flags(unsigned long orig_flags, unsigned long flags)
1851 {
1852 	current->flags &= ~flags;
1853 	current->flags |= orig_flags & flags;
1854 }
1855 
1856 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
1857 extern int task_can_attach(struct task_struct *p);
1858 extern int dl_bw_alloc(int cpu, u64 dl_bw);
1859 extern void dl_bw_free(int cpu, u64 dl_bw);
1860 #ifdef CONFIG_SMP
1861 
1862 /* do_set_cpus_allowed() - consider using set_cpus_allowed_ptr() instead */
1863 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
1864 
1865 /**
1866  * set_cpus_allowed_ptr - set CPU affinity mask of a task
1867  * @p: the task
1868  * @new_mask: CPU affinity mask
1869  *
1870  * Return: zero if successful, or a negative error code
1871  */
1872 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
1873 extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node);
1874 extern void release_user_cpus_ptr(struct task_struct *p);
1875 extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask);
1876 extern void force_compatible_cpus_allowed_ptr(struct task_struct *p);
1877 extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p);
1878 #else
do_set_cpus_allowed(struct task_struct * p,const struct cpumask * new_mask)1879 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
1880 {
1881 }
set_cpus_allowed_ptr(struct task_struct * p,const struct cpumask * new_mask)1882 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
1883 {
1884 	if (!cpumask_test_cpu(0, new_mask))
1885 		return -EINVAL;
1886 	return 0;
1887 }
dup_user_cpus_ptr(struct task_struct * dst,struct task_struct * src,int node)1888 static inline int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node)
1889 {
1890 	if (src->user_cpus_ptr)
1891 		return -EINVAL;
1892 	return 0;
1893 }
release_user_cpus_ptr(struct task_struct * p)1894 static inline void release_user_cpus_ptr(struct task_struct *p)
1895 {
1896 	WARN_ON(p->user_cpus_ptr);
1897 }
1898 
dl_task_check_affinity(struct task_struct * p,const struct cpumask * mask)1899 static inline int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask)
1900 {
1901 	return 0;
1902 }
1903 #endif
1904 
1905 extern int yield_to(struct task_struct *p, bool preempt);
1906 extern void set_user_nice(struct task_struct *p, long nice);
1907 extern int task_prio(const struct task_struct *p);
1908 
1909 /**
1910  * task_nice - return the nice value of a given task.
1911  * @p: the task in question.
1912  *
1913  * Return: The nice value [ -20 ... 0 ... 19 ].
1914  */
task_nice(const struct task_struct * p)1915 static inline int task_nice(const struct task_struct *p)
1916 {
1917 	return PRIO_TO_NICE((p)->static_prio);
1918 }
1919 
1920 extern int can_nice(const struct task_struct *p, const int nice);
1921 extern int task_curr(const struct task_struct *p);
1922 extern int idle_cpu(int cpu);
1923 extern int available_idle_cpu(int cpu);
1924 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *);
1925 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *);
1926 extern void sched_set_fifo(struct task_struct *p);
1927 extern void sched_set_fifo_low(struct task_struct *p);
1928 extern void sched_set_normal(struct task_struct *p, int nice);
1929 extern int sched_setattr(struct task_struct *, const struct sched_attr *);
1930 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *);
1931 extern struct task_struct *idle_task(int cpu);
1932 
1933 /**
1934  * is_idle_task - is the specified task an idle task?
1935  * @p: the task in question.
1936  *
1937  * Return: 1 if @p is an idle task. 0 otherwise.
1938  */
is_idle_task(const struct task_struct * p)1939 static __always_inline bool is_idle_task(const struct task_struct *p)
1940 {
1941 	return !!(p->flags & PF_IDLE);
1942 }
1943 
1944 extern struct task_struct *curr_task(int cpu);
1945 extern void ia64_set_curr_task(int cpu, struct task_struct *p);
1946 
1947 void yield(void);
1948 
1949 union thread_union {
1950 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK
1951 	struct task_struct task;
1952 #endif
1953 #ifndef CONFIG_THREAD_INFO_IN_TASK
1954 	struct thread_info thread_info;
1955 #endif
1956 	unsigned long stack[THREAD_SIZE/sizeof(long)];
1957 };
1958 
1959 #ifndef CONFIG_THREAD_INFO_IN_TASK
1960 extern struct thread_info init_thread_info;
1961 #endif
1962 
1963 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
1964 
1965 #ifdef CONFIG_THREAD_INFO_IN_TASK
1966 # define task_thread_info(task)	(&(task)->thread_info)
1967 #elif !defined(__HAVE_THREAD_FUNCTIONS)
1968 # define task_thread_info(task)	((struct thread_info *)(task)->stack)
1969 #endif
1970 
1971 /*
1972  * find a task by one of its numerical ids
1973  *
1974  * find_task_by_pid_ns():
1975  *      finds a task by its pid in the specified namespace
1976  * find_task_by_vpid():
1977  *      finds a task by its virtual pid
1978  *
1979  * see also find_vpid() etc in include/linux/pid.h
1980  */
1981 
1982 extern struct task_struct *find_task_by_vpid(pid_t nr);
1983 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns);
1984 
1985 /*
1986  * find a task by its virtual pid and get the task struct
1987  */
1988 extern struct task_struct *find_get_task_by_vpid(pid_t nr);
1989 
1990 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
1991 extern int wake_up_process(struct task_struct *tsk);
1992 extern void wake_up_new_task(struct task_struct *tsk);
1993 
1994 #ifdef CONFIG_SMP
1995 extern void kick_process(struct task_struct *tsk);
1996 #else
kick_process(struct task_struct * tsk)1997 static inline void kick_process(struct task_struct *tsk) { }
1998 #endif
1999 
2000 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
2001 
set_task_comm(struct task_struct * tsk,const char * from)2002 static inline void set_task_comm(struct task_struct *tsk, const char *from)
2003 {
2004 	__set_task_comm(tsk, from, false);
2005 }
2006 
2007 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk);
2008 #define get_task_comm(buf, tsk) ({			\
2009 	BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN);	\
2010 	__get_task_comm(buf, sizeof(buf), tsk);		\
2011 })
2012 
2013 #ifdef CONFIG_SMP
scheduler_ipi(void)2014 static __always_inline void scheduler_ipi(void)
2015 {
2016 	/*
2017 	 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting
2018 	 * TIF_NEED_RESCHED remotely (for the first time) will also send
2019 	 * this IPI.
2020 	 */
2021 	preempt_fold_need_resched();
2022 }
2023 #else
scheduler_ipi(void)2024 static inline void scheduler_ipi(void) { }
2025 #endif
2026 
2027 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state);
2028 
2029 /*
2030  * Set thread flags in other task's structures.
2031  * See asm/thread_info.h for TIF_xxxx flags available:
2032  */
set_tsk_thread_flag(struct task_struct * tsk,int flag)2033 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2034 {
2035 	set_ti_thread_flag(task_thread_info(tsk), flag);
2036 }
2037 
clear_tsk_thread_flag(struct task_struct * tsk,int flag)2038 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2039 {
2040 	clear_ti_thread_flag(task_thread_info(tsk), flag);
2041 }
2042 
update_tsk_thread_flag(struct task_struct * tsk,int flag,bool value)2043 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag,
2044 					  bool value)
2045 {
2046 	update_ti_thread_flag(task_thread_info(tsk), flag, value);
2047 }
2048 
test_and_set_tsk_thread_flag(struct task_struct * tsk,int flag)2049 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2050 {
2051 	return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2052 }
2053 
test_and_clear_tsk_thread_flag(struct task_struct * tsk,int flag)2054 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2055 {
2056 	return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2057 }
2058 
test_tsk_thread_flag(struct task_struct * tsk,int flag)2059 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2060 {
2061 	return test_ti_thread_flag(task_thread_info(tsk), flag);
2062 }
2063 
set_tsk_need_resched(struct task_struct * tsk)2064 static inline void set_tsk_need_resched(struct task_struct *tsk)
2065 {
2066 	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2067 }
2068 
clear_tsk_need_resched(struct task_struct * tsk)2069 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2070 {
2071 	clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2072 }
2073 
test_tsk_need_resched(struct task_struct * tsk)2074 static inline int test_tsk_need_resched(struct task_struct *tsk)
2075 {
2076 	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2077 }
2078 
2079 /*
2080  * cond_resched() and cond_resched_lock(): latency reduction via
2081  * explicit rescheduling in places that are safe. The return
2082  * value indicates whether a reschedule was done in fact.
2083  * cond_resched_lock() will drop the spinlock before scheduling,
2084  */
2085 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC)
2086 extern int __cond_resched(void);
2087 
2088 #if defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL)
2089 
2090 void sched_dynamic_klp_enable(void);
2091 void sched_dynamic_klp_disable(void);
2092 
2093 DECLARE_STATIC_CALL(cond_resched, __cond_resched);
2094 
_cond_resched(void)2095 static __always_inline int _cond_resched(void)
2096 {
2097 	return static_call_mod(cond_resched)();
2098 }
2099 
2100 #elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY)
2101 
2102 extern int dynamic_cond_resched(void);
2103 
_cond_resched(void)2104 static __always_inline int _cond_resched(void)
2105 {
2106 	return dynamic_cond_resched();
2107 }
2108 
2109 #else /* !CONFIG_PREEMPTION */
2110 
_cond_resched(void)2111 static inline int _cond_resched(void)
2112 {
2113 	klp_sched_try_switch();
2114 	return __cond_resched();
2115 }
2116 
2117 #endif /* PREEMPT_DYNAMIC && CONFIG_HAVE_PREEMPT_DYNAMIC_CALL */
2118 
2119 #else /* CONFIG_PREEMPTION && !CONFIG_PREEMPT_DYNAMIC */
2120 
_cond_resched(void)2121 static inline int _cond_resched(void)
2122 {
2123 	klp_sched_try_switch();
2124 	return 0;
2125 }
2126 
2127 #endif /* !CONFIG_PREEMPTION || CONFIG_PREEMPT_DYNAMIC */
2128 
2129 #define cond_resched() ({			\
2130 	__might_resched(__FILE__, __LINE__, 0);	\
2131 	_cond_resched();			\
2132 })
2133 
2134 extern int __cond_resched_lock(spinlock_t *lock);
2135 extern int __cond_resched_rwlock_read(rwlock_t *lock);
2136 extern int __cond_resched_rwlock_write(rwlock_t *lock);
2137 
2138 #define MIGHT_RESCHED_RCU_SHIFT		8
2139 #define MIGHT_RESCHED_PREEMPT_MASK	((1U << MIGHT_RESCHED_RCU_SHIFT) - 1)
2140 
2141 #ifndef CONFIG_PREEMPT_RT
2142 /*
2143  * Non RT kernels have an elevated preempt count due to the held lock,
2144  * but are not allowed to be inside a RCU read side critical section
2145  */
2146 # define PREEMPT_LOCK_RESCHED_OFFSETS	PREEMPT_LOCK_OFFSET
2147 #else
2148 /*
2149  * spin/rw_lock() on RT implies rcu_read_lock(). The might_sleep() check in
2150  * cond_resched*lock() has to take that into account because it checks for
2151  * preempt_count() and rcu_preempt_depth().
2152  */
2153 # define PREEMPT_LOCK_RESCHED_OFFSETS	\
2154 	(PREEMPT_LOCK_OFFSET + (1U << MIGHT_RESCHED_RCU_SHIFT))
2155 #endif
2156 
2157 #define cond_resched_lock(lock) ({						\
2158 	__might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS);	\
2159 	__cond_resched_lock(lock);						\
2160 })
2161 
2162 #define cond_resched_rwlock_read(lock) ({					\
2163 	__might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS);	\
2164 	__cond_resched_rwlock_read(lock);					\
2165 })
2166 
2167 #define cond_resched_rwlock_write(lock) ({					\
2168 	__might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS);	\
2169 	__cond_resched_rwlock_write(lock);					\
2170 })
2171 
cond_resched_rcu(void)2172 static inline void cond_resched_rcu(void)
2173 {
2174 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
2175 	rcu_read_unlock();
2176 	cond_resched();
2177 	rcu_read_lock();
2178 #endif
2179 }
2180 
2181 #ifdef CONFIG_PREEMPT_DYNAMIC
2182 
2183 extern bool preempt_model_none(void);
2184 extern bool preempt_model_voluntary(void);
2185 extern bool preempt_model_full(void);
2186 
2187 #else
2188 
preempt_model_none(void)2189 static inline bool preempt_model_none(void)
2190 {
2191 	return IS_ENABLED(CONFIG_PREEMPT_NONE);
2192 }
preempt_model_voluntary(void)2193 static inline bool preempt_model_voluntary(void)
2194 {
2195 	return IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY);
2196 }
preempt_model_full(void)2197 static inline bool preempt_model_full(void)
2198 {
2199 	return IS_ENABLED(CONFIG_PREEMPT);
2200 }
2201 
2202 #endif
2203 
preempt_model_rt(void)2204 static inline bool preempt_model_rt(void)
2205 {
2206 	return IS_ENABLED(CONFIG_PREEMPT_RT);
2207 }
2208 
2209 /*
2210  * Does the preemption model allow non-cooperative preemption?
2211  *
2212  * For !CONFIG_PREEMPT_DYNAMIC kernels this is an exact match with
2213  * CONFIG_PREEMPTION; for CONFIG_PREEMPT_DYNAMIC this doesn't work as the
2214  * kernel is *built* with CONFIG_PREEMPTION=y but may run with e.g. the
2215  * PREEMPT_NONE model.
2216  */
preempt_model_preemptible(void)2217 static inline bool preempt_model_preemptible(void)
2218 {
2219 	return preempt_model_full() || preempt_model_rt();
2220 }
2221 
2222 /*
2223  * Does a critical section need to be broken due to another
2224  * task waiting?: (technically does not depend on CONFIG_PREEMPTION,
2225  * but a general need for low latency)
2226  */
spin_needbreak(spinlock_t * lock)2227 static inline int spin_needbreak(spinlock_t *lock)
2228 {
2229 #ifdef CONFIG_PREEMPTION
2230 	return spin_is_contended(lock);
2231 #else
2232 	return 0;
2233 #endif
2234 }
2235 
2236 /*
2237  * Check if a rwlock is contended.
2238  * Returns non-zero if there is another task waiting on the rwlock.
2239  * Returns zero if the lock is not contended or the system / underlying
2240  * rwlock implementation does not support contention detection.
2241  * Technically does not depend on CONFIG_PREEMPTION, but a general need
2242  * for low latency.
2243  */
rwlock_needbreak(rwlock_t * lock)2244 static inline int rwlock_needbreak(rwlock_t *lock)
2245 {
2246 #ifdef CONFIG_PREEMPTION
2247 	return rwlock_is_contended(lock);
2248 #else
2249 	return 0;
2250 #endif
2251 }
2252 
need_resched(void)2253 static __always_inline bool need_resched(void)
2254 {
2255 	return unlikely(tif_need_resched());
2256 }
2257 
2258 /*
2259  * Wrappers for p->thread_info->cpu access. No-op on UP.
2260  */
2261 #ifdef CONFIG_SMP
2262 
task_cpu(const struct task_struct * p)2263 static inline unsigned int task_cpu(const struct task_struct *p)
2264 {
2265 	return READ_ONCE(task_thread_info(p)->cpu);
2266 }
2267 
2268 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2269 
2270 #else
2271 
task_cpu(const struct task_struct * p)2272 static inline unsigned int task_cpu(const struct task_struct *p)
2273 {
2274 	return 0;
2275 }
2276 
set_task_cpu(struct task_struct * p,unsigned int cpu)2277 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2278 {
2279 }
2280 
2281 #endif /* CONFIG_SMP */
2282 
2283 extern bool sched_task_on_rq(struct task_struct *p);
2284 extern unsigned long get_wchan(struct task_struct *p);
2285 extern struct task_struct *cpu_curr_snapshot(int cpu);
2286 
2287 /*
2288  * In order to reduce various lock holder preemption latencies provide an
2289  * interface to see if a vCPU is currently running or not.
2290  *
2291  * This allows us to terminate optimistic spin loops and block, analogous to
2292  * the native optimistic spin heuristic of testing if the lock owner task is
2293  * running or not.
2294  */
2295 #ifndef vcpu_is_preempted
vcpu_is_preempted(int cpu)2296 static inline bool vcpu_is_preempted(int cpu)
2297 {
2298 	return false;
2299 }
2300 #endif
2301 
2302 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2303 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2304 
2305 #ifndef TASK_SIZE_OF
2306 #define TASK_SIZE_OF(tsk)	TASK_SIZE
2307 #endif
2308 
2309 #ifdef CONFIG_SMP
owner_on_cpu(struct task_struct * owner)2310 static inline bool owner_on_cpu(struct task_struct *owner)
2311 {
2312 	/*
2313 	 * As lock holder preemption issue, we both skip spinning if
2314 	 * task is not on cpu or its cpu is preempted
2315 	 */
2316 	return READ_ONCE(owner->on_cpu) && !vcpu_is_preempted(task_cpu(owner));
2317 }
2318 
2319 /* Returns effective CPU energy utilization, as seen by the scheduler */
2320 unsigned long sched_cpu_util(int cpu);
2321 #endif /* CONFIG_SMP */
2322 
2323 #ifdef CONFIG_RSEQ
2324 
2325 /*
2326  * Map the event mask on the user-space ABI enum rseq_cs_flags
2327  * for direct mask checks.
2328  */
2329 enum rseq_event_mask_bits {
2330 	RSEQ_EVENT_PREEMPT_BIT	= RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT,
2331 	RSEQ_EVENT_SIGNAL_BIT	= RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT,
2332 	RSEQ_EVENT_MIGRATE_BIT	= RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT,
2333 };
2334 
2335 enum rseq_event_mask {
2336 	RSEQ_EVENT_PREEMPT	= (1U << RSEQ_EVENT_PREEMPT_BIT),
2337 	RSEQ_EVENT_SIGNAL	= (1U << RSEQ_EVENT_SIGNAL_BIT),
2338 	RSEQ_EVENT_MIGRATE	= (1U << RSEQ_EVENT_MIGRATE_BIT),
2339 };
2340 
rseq_set_notify_resume(struct task_struct * t)2341 static inline void rseq_set_notify_resume(struct task_struct *t)
2342 {
2343 	if (t->rseq)
2344 		set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
2345 }
2346 
2347 void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs);
2348 
rseq_handle_notify_resume(struct ksignal * ksig,struct pt_regs * regs)2349 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
2350 					     struct pt_regs *regs)
2351 {
2352 	if (current->rseq)
2353 		__rseq_handle_notify_resume(ksig, regs);
2354 }
2355 
rseq_signal_deliver(struct ksignal * ksig,struct pt_regs * regs)2356 static inline void rseq_signal_deliver(struct ksignal *ksig,
2357 				       struct pt_regs *regs)
2358 {
2359 	preempt_disable();
2360 	__set_bit(RSEQ_EVENT_SIGNAL_BIT, &current->rseq_event_mask);
2361 	preempt_enable();
2362 	rseq_handle_notify_resume(ksig, regs);
2363 }
2364 
2365 /* rseq_preempt() requires preemption to be disabled. */
rseq_preempt(struct task_struct * t)2366 static inline void rseq_preempt(struct task_struct *t)
2367 {
2368 	__set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask);
2369 	rseq_set_notify_resume(t);
2370 }
2371 
2372 /* rseq_migrate() requires preemption to be disabled. */
rseq_migrate(struct task_struct * t)2373 static inline void rseq_migrate(struct task_struct *t)
2374 {
2375 	__set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask);
2376 	rseq_set_notify_resume(t);
2377 }
2378 
2379 /*
2380  * If parent process has a registered restartable sequences area, the
2381  * child inherits. Unregister rseq for a clone with CLONE_VM set.
2382  */
rseq_fork(struct task_struct * t,unsigned long clone_flags)2383 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
2384 {
2385 	if (clone_flags & CLONE_VM) {
2386 		t->rseq = NULL;
2387 		t->rseq_len = 0;
2388 		t->rseq_sig = 0;
2389 		t->rseq_event_mask = 0;
2390 	} else {
2391 		t->rseq = current->rseq;
2392 		t->rseq_len = current->rseq_len;
2393 		t->rseq_sig = current->rseq_sig;
2394 		t->rseq_event_mask = current->rseq_event_mask;
2395 	}
2396 }
2397 
rseq_execve(struct task_struct * t)2398 static inline void rseq_execve(struct task_struct *t)
2399 {
2400 	t->rseq = NULL;
2401 	t->rseq_len = 0;
2402 	t->rseq_sig = 0;
2403 	t->rseq_event_mask = 0;
2404 }
2405 
2406 #else
2407 
rseq_set_notify_resume(struct task_struct * t)2408 static inline void rseq_set_notify_resume(struct task_struct *t)
2409 {
2410 }
rseq_handle_notify_resume(struct ksignal * ksig,struct pt_regs * regs)2411 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
2412 					     struct pt_regs *regs)
2413 {
2414 }
rseq_signal_deliver(struct ksignal * ksig,struct pt_regs * regs)2415 static inline void rseq_signal_deliver(struct ksignal *ksig,
2416 				       struct pt_regs *regs)
2417 {
2418 }
rseq_preempt(struct task_struct * t)2419 static inline void rseq_preempt(struct task_struct *t)
2420 {
2421 }
rseq_migrate(struct task_struct * t)2422 static inline void rseq_migrate(struct task_struct *t)
2423 {
2424 }
rseq_fork(struct task_struct * t,unsigned long clone_flags)2425 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
2426 {
2427 }
rseq_execve(struct task_struct * t)2428 static inline void rseq_execve(struct task_struct *t)
2429 {
2430 }
2431 
2432 #endif
2433 
2434 #ifdef CONFIG_DEBUG_RSEQ
2435 
2436 void rseq_syscall(struct pt_regs *regs);
2437 
2438 #else
2439 
rseq_syscall(struct pt_regs * regs)2440 static inline void rseq_syscall(struct pt_regs *regs)
2441 {
2442 }
2443 
2444 #endif
2445 
2446 #ifdef CONFIG_SCHED_CORE
2447 extern void sched_core_free(struct task_struct *tsk);
2448 extern void sched_core_fork(struct task_struct *p);
2449 extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type,
2450 				unsigned long uaddr);
2451 extern int sched_core_idle_cpu(int cpu);
2452 #else
sched_core_free(struct task_struct * tsk)2453 static inline void sched_core_free(struct task_struct *tsk) { }
sched_core_fork(struct task_struct * p)2454 static inline void sched_core_fork(struct task_struct *p) { }
sched_core_idle_cpu(int cpu)2455 static inline int sched_core_idle_cpu(int cpu) { return idle_cpu(cpu); }
2456 #endif
2457 
2458 extern void sched_set_stop_task(int cpu, struct task_struct *stop);
2459 
2460 #endif
2461