xref: /linux/include/linux/sched.h (revision 6c7340a7a8d2b6ecad1ad108f6daa73ba1dc082f)
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 #include <asm/processor.h>
14 #include <linux/thread_info.h>
15 #include <linux/preempt.h>
16 #include <linux/cpumask_types.h>
17 
18 #include <linux/cache.h>
19 #include <linux/irqflags_types.h>
20 #include <linux/smp_types.h>
21 #include <linux/pid_types.h>
22 #include <linux/sem_types.h>
23 #include <linux/shm.h>
24 #include <linux/kmsan_types.h>
25 #include <linux/mutex_types.h>
26 #include <linux/plist_types.h>
27 #include <linux/hrtimer_types.h>
28 #include <linux/timer_types.h>
29 #include <linux/seccomp_types.h>
30 #include <linux/nodemask_types.h>
31 #include <linux/refcount_types.h>
32 #include <linux/resource.h>
33 #include <linux/latencytop.h>
34 #include <linux/sched/prio.h>
35 #include <linux/sched/types.h>
36 #include <linux/signal_types.h>
37 #include <linux/spinlock.h>
38 #include <linux/syscall_user_dispatch_types.h>
39 #include <linux/mm_types_task.h>
40 #include <linux/netdevice_xmit.h>
41 #include <linux/task_io_accounting.h>
42 #include <linux/posix-timers_types.h>
43 #include <linux/restart_block.h>
44 #include <uapi/linux/rseq.h>
45 #include <linux/seqlock_types.h>
46 #include <linux/kcsan.h>
47 #include <linux/rv.h>
48 #include <linux/uidgid_types.h>
49 #include <linux/tracepoint-defs.h>
50 #include <linux/unwind_deferred_types.h>
51 #include <asm/kmap_size.h>
52 #ifndef COMPILE_OFFSETS
53 #include <generated/rq-offsets.h>
54 #endif
55 
56 /* task_struct member predeclarations (sorted alphabetically): */
57 struct audit_context;
58 struct bio_list;
59 struct blk_plug;
60 struct bpf_local_storage;
61 struct bpf_run_ctx;
62 struct bpf_net_context;
63 struct capture_control;
64 struct cfs_rq;
65 struct fs_struct;
66 struct futex_pi_state;
67 struct io_context;
68 struct io_uring_task;
69 struct mempolicy;
70 struct nameidata;
71 struct nsproxy;
72 struct perf_event_context;
73 struct perf_ctx_data;
74 struct pid_namespace;
75 struct pipe_inode_info;
76 struct rcu_node;
77 struct reclaim_state;
78 struct robust_list_head;
79 struct root_domain;
80 struct rq;
81 struct sched_attr;
82 struct sched_dl_entity;
83 struct seq_file;
84 struct sighand_struct;
85 struct signal_struct;
86 struct task_delay_info;
87 struct task_group;
88 struct task_struct;
89 struct user_event_mm;
90 
91 #include <linux/sched/ext.h>
92 
93 /*
94  * Task state bitmask. NOTE! These bits are also
95  * encoded in fs/proc/array.c: get_task_state().
96  *
97  * We have two separate sets of flags: task->__state
98  * is about runnability, while task->exit_state are
99  * about the task exiting. Confusing, but this way
100  * modifying one set can't modify the other one by
101  * mistake.
102  */
103 
104 /* Used in tsk->__state: */
105 #define TASK_RUNNING			0x00000000
106 #define TASK_INTERRUPTIBLE		0x00000001
107 #define TASK_UNINTERRUPTIBLE		0x00000002
108 #define __TASK_STOPPED			0x00000004
109 #define __TASK_TRACED			0x00000008
110 /* Used in tsk->exit_state: */
111 #define EXIT_DEAD			0x00000010
112 #define EXIT_ZOMBIE			0x00000020
113 #define EXIT_TRACE			(EXIT_ZOMBIE | EXIT_DEAD)
114 /* Used in tsk->__state again: */
115 #define TASK_PARKED			0x00000040
116 #define TASK_DEAD			0x00000080
117 #define TASK_WAKEKILL			0x00000100
118 #define TASK_WAKING			0x00000200
119 #define TASK_NOLOAD			0x00000400
120 #define TASK_NEW			0x00000800
121 #define TASK_RTLOCK_WAIT		0x00001000
122 #define TASK_FREEZABLE			0x00002000
123 #define __TASK_FREEZABLE_UNSAFE	       (0x00004000 * IS_ENABLED(CONFIG_LOCKDEP))
124 #define TASK_FROZEN			0x00008000
125 #define TASK_STATE_MAX			0x00010000
126 
127 #define TASK_ANY			(TASK_STATE_MAX-1)
128 
129 /*
130  * DO NOT ADD ANY NEW USERS !
131  */
132 #define TASK_FREEZABLE_UNSAFE		(TASK_FREEZABLE | __TASK_FREEZABLE_UNSAFE)
133 
134 /* Convenience macros for the sake of set_current_state: */
135 #define TASK_KILLABLE			(TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
136 #define TASK_STOPPED			(TASK_WAKEKILL | __TASK_STOPPED)
137 #define TASK_TRACED			__TASK_TRACED
138 
139 #define TASK_IDLE			(TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
140 
141 /* Convenience macros for the sake of wake_up(): */
142 #define TASK_NORMAL			(TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
143 
144 /* get_task_state(): */
145 #define TASK_REPORT			(TASK_RUNNING | TASK_INTERRUPTIBLE | \
146 					 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
147 					 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
148 					 TASK_PARKED)
149 
150 #define task_is_running(task)		(READ_ONCE((task)->__state) == TASK_RUNNING)
151 
152 #define task_is_traced(task)		((READ_ONCE(task->jobctl) & JOBCTL_TRACED) != 0)
153 #define task_is_stopped(task)		((READ_ONCE(task->jobctl) & JOBCTL_STOPPED) != 0)
154 #define task_is_stopped_or_traced(task)	((READ_ONCE(task->jobctl) & (JOBCTL_STOPPED | JOBCTL_TRACED)) != 0)
155 
156 /*
157  * Special states are those that do not use the normal wait-loop pattern. See
158  * the comment with set_special_state().
159  */
160 #define is_special_task_state(state)					\
161 	((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED |	\
162 		    TASK_DEAD | TASK_FROZEN))
163 
164 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
165 # define debug_normal_state_change(state_value)				\
166 	do {								\
167 		WARN_ON_ONCE(is_special_task_state(state_value));	\
168 		current->task_state_change = _THIS_IP_;			\
169 	} while (0)
170 
171 # define debug_special_state_change(state_value)			\
172 	do {								\
173 		WARN_ON_ONCE(!is_special_task_state(state_value));	\
174 		current->task_state_change = _THIS_IP_;			\
175 	} while (0)
176 
177 # define debug_rtlock_wait_set_state()					\
178 	do {								 \
179 		current->saved_state_change = current->task_state_change;\
180 		current->task_state_change = _THIS_IP_;			 \
181 	} while (0)
182 
183 # define debug_rtlock_wait_restore_state()				\
184 	do {								 \
185 		current->task_state_change = current->saved_state_change;\
186 	} while (0)
187 
188 #else
189 # define debug_normal_state_change(cond)	do { } while (0)
190 # define debug_special_state_change(cond)	do { } while (0)
191 # define debug_rtlock_wait_set_state()		do { } while (0)
192 # define debug_rtlock_wait_restore_state()	do { } while (0)
193 #endif
194 
195 #define trace_set_current_state(state_value)                     \
196 	do {                                                     \
197 		if (tracepoint_enabled(sched_set_state_tp))      \
198 			__trace_set_current_state(state_value); \
199 	} while (0)
200 
201 /*
202  * set_current_state() includes a barrier so that the write of current->__state
203  * is correctly serialised wrt the caller's subsequent test of whether to
204  * actually sleep:
205  *
206  *   for (;;) {
207  *	set_current_state(TASK_UNINTERRUPTIBLE);
208  *	if (CONDITION)
209  *	   break;
210  *
211  *	schedule();
212  *   }
213  *   __set_current_state(TASK_RUNNING);
214  *
215  * If the caller does not need such serialisation (because, for instance, the
216  * CONDITION test and condition change and wakeup are under the same lock) then
217  * use __set_current_state().
218  *
219  * The above is typically ordered against the wakeup, which does:
220  *
221  *   CONDITION = 1;
222  *   wake_up_state(p, TASK_UNINTERRUPTIBLE);
223  *
224  * where wake_up_state()/try_to_wake_up() executes a full memory barrier before
225  * accessing p->__state.
226  *
227  * Wakeup will do: if (@state & p->__state) p->__state = TASK_RUNNING, that is,
228  * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
229  * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
230  *
231  * However, with slightly different timing the wakeup TASK_RUNNING store can
232  * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not
233  * a problem either because that will result in one extra go around the loop
234  * and our @cond test will save the day.
235  *
236  * Also see the comments of try_to_wake_up().
237  */
238 #define __set_current_state(state_value)				\
239 	do {								\
240 		debug_normal_state_change((state_value));		\
241 		trace_set_current_state(state_value);			\
242 		WRITE_ONCE(current->__state, (state_value));		\
243 	} while (0)
244 
245 #define set_current_state(state_value)					\
246 	do {								\
247 		debug_normal_state_change((state_value));		\
248 		trace_set_current_state(state_value);			\
249 		smp_store_mb(current->__state, (state_value));		\
250 	} while (0)
251 
252 /*
253  * set_special_state() should be used for those states when the blocking task
254  * can not use the regular condition based wait-loop. In that case we must
255  * serialize against wakeups such that any possible in-flight TASK_RUNNING
256  * stores will not collide with our state change.
257  */
258 #define set_special_state(state_value)					\
259 	do {								\
260 		unsigned long flags; /* may shadow */			\
261 									\
262 		raw_spin_lock_irqsave(&current->pi_lock, flags);	\
263 		debug_special_state_change((state_value));		\
264 		trace_set_current_state(state_value);			\
265 		WRITE_ONCE(current->__state, (state_value));		\
266 		raw_spin_unlock_irqrestore(&current->pi_lock, flags);	\
267 	} while (0)
268 
269 /*
270  * PREEMPT_RT specific variants for "sleeping" spin/rwlocks
271  *
272  * RT's spin/rwlock substitutions are state preserving. The state of the
273  * task when blocking on the lock is saved in task_struct::saved_state and
274  * restored after the lock has been acquired.  These operations are
275  * serialized by task_struct::pi_lock against try_to_wake_up(). Any non RT
276  * lock related wakeups while the task is blocked on the lock are
277  * redirected to operate on task_struct::saved_state to ensure that these
278  * are not dropped. On restore task_struct::saved_state is set to
279  * TASK_RUNNING so any wakeup attempt redirected to saved_state will fail.
280  *
281  * The lock operation looks like this:
282  *
283  *	current_save_and_set_rtlock_wait_state();
284  *	for (;;) {
285  *		if (try_lock())
286  *			break;
287  *		raw_spin_unlock_irq(&lock->wait_lock);
288  *		schedule_rtlock();
289  *		raw_spin_lock_irq(&lock->wait_lock);
290  *		set_current_state(TASK_RTLOCK_WAIT);
291  *	}
292  *	current_restore_rtlock_saved_state();
293  */
294 #define current_save_and_set_rtlock_wait_state()			\
295 	do {								\
296 		lockdep_assert_irqs_disabled();				\
297 		raw_spin_lock(&current->pi_lock);			\
298 		current->saved_state = current->__state;		\
299 		debug_rtlock_wait_set_state();				\
300 		trace_set_current_state(TASK_RTLOCK_WAIT);		\
301 		WRITE_ONCE(current->__state, TASK_RTLOCK_WAIT);		\
302 		raw_spin_unlock(&current->pi_lock);			\
303 	} while (0);
304 
305 #define current_restore_rtlock_saved_state()				\
306 	do {								\
307 		lockdep_assert_irqs_disabled();				\
308 		raw_spin_lock(&current->pi_lock);			\
309 		debug_rtlock_wait_restore_state();			\
310 		trace_set_current_state(current->saved_state);		\
311 		WRITE_ONCE(current->__state, current->saved_state);	\
312 		current->saved_state = TASK_RUNNING;			\
313 		raw_spin_unlock(&current->pi_lock);			\
314 	} while (0);
315 
316 #define get_current_state()	READ_ONCE(current->__state)
317 
318 /*
319  * Define the task command name length as enum, then it can be visible to
320  * BPF programs.
321  */
322 enum {
323 	TASK_COMM_LEN = 16,
324 };
325 
326 extern void sched_tick(void);
327 
328 #define	MAX_SCHEDULE_TIMEOUT		LONG_MAX
329 
330 extern long schedule_timeout(long timeout);
331 extern long schedule_timeout_interruptible(long timeout);
332 extern long schedule_timeout_killable(long timeout);
333 extern long schedule_timeout_uninterruptible(long timeout);
334 extern long schedule_timeout_idle(long timeout);
335 asmlinkage void schedule(void);
336 extern void schedule_preempt_disabled(void);
337 asmlinkage void preempt_schedule_irq(void);
338 #ifdef CONFIG_PREEMPT_RT
339  extern void schedule_rtlock(void);
340 #endif
341 
342 extern int __must_check io_schedule_prepare(void);
343 extern void io_schedule_finish(int token);
344 extern long io_schedule_timeout(long timeout);
345 extern void io_schedule(void);
346 
347 /* wrapper functions to trace from this header file */
348 DECLARE_TRACEPOINT(sched_set_state_tp);
349 extern void __trace_set_current_state(int state_value);
350 DECLARE_TRACEPOINT(sched_set_need_resched_tp);
351 extern void __trace_set_need_resched(struct task_struct *curr, int tif);
352 
353 /**
354  * struct prev_cputime - snapshot of system and user cputime
355  * @utime: time spent in user mode
356  * @stime: time spent in system mode
357  * @lock: protects the above two fields
358  *
359  * Stores previous user/system time values such that we can guarantee
360  * monotonicity.
361  */
362 struct prev_cputime {
363 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
364 	u64				utime;
365 	u64				stime;
366 	raw_spinlock_t			lock;
367 #endif
368 };
369 
370 enum vtime_state {
371 	/* Task is sleeping or running in a CPU with VTIME inactive: */
372 	VTIME_INACTIVE = 0,
373 	/* Task is idle */
374 	VTIME_IDLE,
375 	/* Task runs in kernelspace in a CPU with VTIME active: */
376 	VTIME_SYS,
377 	/* Task runs in userspace in a CPU with VTIME active: */
378 	VTIME_USER,
379 	/* Task runs as guests in a CPU with VTIME active: */
380 	VTIME_GUEST,
381 };
382 
383 struct vtime {
384 	seqcount_t		seqcount;
385 	unsigned long long	starttime;
386 	enum vtime_state	state;
387 	unsigned int		cpu;
388 	u64			utime;
389 	u64			stime;
390 	u64			gtime;
391 };
392 
393 /*
394  * Utilization clamp constraints.
395  * @UCLAMP_MIN:	Minimum utilization
396  * @UCLAMP_MAX:	Maximum utilization
397  * @UCLAMP_CNT:	Utilization clamp constraints count
398  */
399 enum uclamp_id {
400 	UCLAMP_MIN = 0,
401 	UCLAMP_MAX,
402 	UCLAMP_CNT
403 };
404 
405 extern struct root_domain def_root_domain;
406 extern struct mutex sched_domains_mutex;
407 extern void sched_domains_mutex_lock(void);
408 extern void sched_domains_mutex_unlock(void);
409 
410 struct sched_param {
411 	int sched_priority;
412 };
413 
414 struct sched_info {
415 #ifdef CONFIG_SCHED_INFO
416 	/* Cumulative counters: */
417 
418 	/* # of times we have run on this CPU: */
419 	unsigned long			pcount;
420 
421 	/* Time spent waiting on a runqueue: */
422 	unsigned long long		run_delay;
423 
424 	/* Max time spent waiting on a runqueue: */
425 	unsigned long long		max_run_delay;
426 
427 	/* Min time spent waiting on a runqueue: */
428 	unsigned long long		min_run_delay;
429 
430 	/* Timestamps: */
431 
432 	/* When did we last run on a CPU? */
433 	unsigned long long		last_arrival;
434 
435 	/* When were we last queued to run? */
436 	unsigned long long		last_queued;
437 
438 #endif /* CONFIG_SCHED_INFO */
439 };
440 
441 /*
442  * Integer metrics need fixed point arithmetic, e.g., sched/fair
443  * has a few: load, load_avg, util_avg, freq, and capacity.
444  *
445  * We define a basic fixed point arithmetic range, and then formalize
446  * all these metrics based on that basic range.
447  */
448 # define SCHED_FIXEDPOINT_SHIFT		10
449 # define SCHED_FIXEDPOINT_SCALE		(1L << SCHED_FIXEDPOINT_SHIFT)
450 
451 /* Increase resolution of cpu_capacity calculations */
452 # define SCHED_CAPACITY_SHIFT		SCHED_FIXEDPOINT_SHIFT
453 # define SCHED_CAPACITY_SCALE		(1L << SCHED_CAPACITY_SHIFT)
454 
455 struct load_weight {
456 	unsigned long			weight;
457 	u32				inv_weight;
458 };
459 
460 /*
461  * The load/runnable/util_avg accumulates an infinite geometric series
462  * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c).
463  *
464  * [load_avg definition]
465  *
466  *   load_avg = runnable% * scale_load_down(load)
467  *
468  * [runnable_avg definition]
469  *
470  *   runnable_avg = runnable% * SCHED_CAPACITY_SCALE
471  *
472  * [util_avg definition]
473  *
474  *   util_avg = running% * SCHED_CAPACITY_SCALE
475  *
476  * where runnable% is the time ratio that a sched_entity is runnable and
477  * running% the time ratio that a sched_entity is running.
478  *
479  * For cfs_rq, they are the aggregated values of all runnable and blocked
480  * sched_entities.
481  *
482  * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU
483  * capacity scaling. The scaling is done through the rq_clock_pelt that is used
484  * for computing those signals (see update_rq_clock_pelt())
485  *
486  * N.B., the above ratios (runnable% and running%) themselves are in the
487  * range of [0, 1]. To do fixed point arithmetics, we therefore scale them
488  * to as large a range as necessary. This is for example reflected by
489  * util_avg's SCHED_CAPACITY_SCALE.
490  *
491  * [Overflow issue]
492  *
493  * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
494  * with the highest load (=88761), always runnable on a single cfs_rq,
495  * and should not overflow as the number already hits PID_MAX_LIMIT.
496  *
497  * For all other cases (including 32-bit kernels), struct load_weight's
498  * weight will overflow first before we do, because:
499  *
500  *    Max(load_avg) <= Max(load.weight)
501  *
502  * Then it is the load_weight's responsibility to consider overflow
503  * issues.
504  */
505 struct sched_avg {
506 	u64				last_update_time;
507 	u64				load_sum;
508 	u64				runnable_sum;
509 	u32				util_sum;
510 	u32				period_contrib;
511 	unsigned long			load_avg;
512 	unsigned long			runnable_avg;
513 	unsigned long			util_avg;
514 	unsigned int			util_est;
515 } ____cacheline_aligned;
516 
517 /*
518  * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg
519  * updates. When a task is dequeued, its util_est should not be updated if its
520  * util_avg has not been updated in the meantime.
521  * This information is mapped into the MSB bit of util_est at dequeue time.
522  * Since max value of util_est for a task is 1024 (PELT util_avg for a task)
523  * it is safe to use MSB.
524  */
525 #define UTIL_EST_WEIGHT_SHIFT		2
526 #define UTIL_AVG_UNCHANGED		0x80000000
527 
528 struct sched_statistics {
529 #ifdef CONFIG_SCHEDSTATS
530 	u64				wait_start;
531 	u64				wait_max;
532 	u64				wait_count;
533 	u64				wait_sum;
534 	u64				iowait_count;
535 	u64				iowait_sum;
536 
537 	u64				sleep_start;
538 	u64				sleep_max;
539 	s64				sum_sleep_runtime;
540 
541 	u64				block_start;
542 	u64				block_max;
543 	s64				sum_block_runtime;
544 
545 	s64				exec_max;
546 	u64				slice_max;
547 
548 	u64				nr_migrations_cold;
549 	u64				nr_failed_migrations_affine;
550 	u64				nr_failed_migrations_running;
551 	u64				nr_failed_migrations_hot;
552 	u64				nr_forced_migrations;
553 
554 	u64				nr_wakeups;
555 	u64				nr_wakeups_sync;
556 	u64				nr_wakeups_migrate;
557 	u64				nr_wakeups_local;
558 	u64				nr_wakeups_remote;
559 	u64				nr_wakeups_affine;
560 	u64				nr_wakeups_affine_attempts;
561 	u64				nr_wakeups_passive;
562 	u64				nr_wakeups_idle;
563 
564 #ifdef CONFIG_SCHED_CORE
565 	u64				core_forceidle_sum;
566 #endif
567 #endif /* CONFIG_SCHEDSTATS */
568 } ____cacheline_aligned;
569 
570 struct sched_entity {
571 	/* For load-balancing: */
572 	struct load_weight		load;
573 	struct rb_node			run_node;
574 	u64				deadline;
575 	u64				min_vruntime;
576 	u64				min_slice;
577 
578 	struct list_head		group_node;
579 	unsigned char			on_rq;
580 	unsigned char			sched_delayed;
581 	unsigned char			rel_deadline;
582 	unsigned char			custom_slice;
583 					/* hole */
584 
585 	u64				exec_start;
586 	u64				sum_exec_runtime;
587 	u64				prev_sum_exec_runtime;
588 	u64				vruntime;
589 	union {
590 		/*
591 		 * When !@on_rq this field is vlag.
592 		 * When cfs_rq->curr == se (which implies @on_rq)
593 		 * this field is vprot. See protect_slice().
594 		 */
595 		s64                     vlag;
596 		u64                     vprot;
597 	};
598 	u64				slice;
599 
600 	u64				nr_migrations;
601 
602 #ifdef CONFIG_FAIR_GROUP_SCHED
603 	int				depth;
604 	struct sched_entity		*parent;
605 	/* rq on which this entity is (to be) queued: */
606 	struct cfs_rq			*cfs_rq;
607 	/* rq "owned" by this entity/group: */
608 	struct cfs_rq			*my_q;
609 	/* cached value of my_q->h_nr_running */
610 	unsigned long			runnable_weight;
611 #endif
612 
613 	/*
614 	 * Per entity load average tracking.
615 	 *
616 	 * Put into separate cache line so it does not
617 	 * collide with read-mostly values above.
618 	 */
619 	struct sched_avg		avg;
620 };
621 
622 struct sched_rt_entity {
623 	struct list_head		run_list;
624 	unsigned long			timeout;
625 	unsigned long			watchdog_stamp;
626 	unsigned int			time_slice;
627 	unsigned short			on_rq;
628 	unsigned short			on_list;
629 
630 	struct sched_rt_entity		*back;
631 #ifdef CONFIG_RT_GROUP_SCHED
632 	struct sched_rt_entity		*parent;
633 	/* rq on which this entity is (to be) queued: */
634 	struct rt_rq			*rt_rq;
635 	/* rq "owned" by this entity/group: */
636 	struct rt_rq			*my_q;
637 #endif
638 } __randomize_layout;
639 
640 typedef bool (*dl_server_has_tasks_f)(struct sched_dl_entity *);
641 typedef struct task_struct *(*dl_server_pick_f)(struct sched_dl_entity *);
642 
643 struct sched_dl_entity {
644 	struct rb_node			rb_node;
645 
646 	/*
647 	 * Original scheduling parameters. Copied here from sched_attr
648 	 * during sched_setattr(), they will remain the same until
649 	 * the next sched_setattr().
650 	 */
651 	u64				dl_runtime;	/* Maximum runtime for each instance	*/
652 	u64				dl_deadline;	/* Relative deadline of each instance	*/
653 	u64				dl_period;	/* Separation of two instances (period) */
654 	u64				dl_bw;		/* dl_runtime / dl_period		*/
655 	u64				dl_density;	/* dl_runtime / dl_deadline		*/
656 
657 	/*
658 	 * Actual scheduling parameters. Initialized with the values above,
659 	 * they are continuously updated during task execution. Note that
660 	 * the remaining runtime could be < 0 in case we are in overrun.
661 	 */
662 	s64				runtime;	/* Remaining runtime for this instance	*/
663 	u64				deadline;	/* Absolute deadline for this instance	*/
664 	unsigned int			flags;		/* Specifying the scheduler behaviour	*/
665 
666 	/*
667 	 * Some bool flags:
668 	 *
669 	 * @dl_throttled tells if we exhausted the runtime. If so, the
670 	 * task has to wait for a replenishment to be performed at the
671 	 * next firing of dl_timer.
672 	 *
673 	 * @dl_yielded tells if task gave up the CPU before consuming
674 	 * all its available runtime during the last job.
675 	 *
676 	 * @dl_non_contending tells if the task is inactive while still
677 	 * contributing to the active utilization. In other words, it
678 	 * indicates if the inactive timer has been armed and its handler
679 	 * has not been executed yet. This flag is useful to avoid race
680 	 * conditions between the inactive timer handler and the wakeup
681 	 * code.
682 	 *
683 	 * @dl_overrun tells if the task asked to be informed about runtime
684 	 * overruns.
685 	 *
686 	 * @dl_server tells if this is a server entity.
687 	 *
688 	 * @dl_defer tells if this is a deferred or regular server. For
689 	 * now only defer server exists.
690 	 *
691 	 * @dl_defer_armed tells if the deferrable server is waiting
692 	 * for the replenishment timer to activate it.
693 	 *
694 	 * @dl_server_active tells if the dlserver is active(started).
695 	 * dlserver is started on first cfs enqueue on an idle runqueue
696 	 * and is stopped when a dequeue results in 0 cfs tasks on the
697 	 * runqueue. In other words, dlserver is active only when cpu's
698 	 * runqueue has atleast one cfs task.
699 	 *
700 	 * @dl_defer_running tells if the deferrable server is actually
701 	 * running, skipping the defer phase.
702 	 */
703 	unsigned int			dl_throttled      : 1;
704 	unsigned int			dl_yielded        : 1;
705 	unsigned int			dl_non_contending : 1;
706 	unsigned int			dl_overrun	  : 1;
707 	unsigned int			dl_server         : 1;
708 	unsigned int			dl_server_active  : 1;
709 	unsigned int			dl_defer	  : 1;
710 	unsigned int			dl_defer_armed	  : 1;
711 	unsigned int			dl_defer_running  : 1;
712 
713 	/*
714 	 * Bandwidth enforcement timer. Each -deadline task has its
715 	 * own bandwidth to be enforced, thus we need one timer per task.
716 	 */
717 	struct hrtimer			dl_timer;
718 
719 	/*
720 	 * Inactive timer, responsible for decreasing the active utilization
721 	 * at the "0-lag time". When a -deadline task blocks, it contributes
722 	 * to GRUB's active utilization until the "0-lag time", hence a
723 	 * timer is needed to decrease the active utilization at the correct
724 	 * time.
725 	 */
726 	struct hrtimer			inactive_timer;
727 
728 	/*
729 	 * Bits for DL-server functionality. Also see the comment near
730 	 * dl_server_update().
731 	 *
732 	 * @rq the runqueue this server is for
733 	 *
734 	 * @server_has_tasks() returns true if @server_pick return a
735 	 * runnable task.
736 	 */
737 	struct rq			*rq;
738 	dl_server_pick_f		server_pick_task;
739 
740 #ifdef CONFIG_RT_MUTEXES
741 	/*
742 	 * Priority Inheritance. When a DEADLINE scheduling entity is boosted
743 	 * pi_se points to the donor, otherwise points to the dl_se it belongs
744 	 * to (the original one/itself).
745 	 */
746 	struct sched_dl_entity *pi_se;
747 #endif
748 };
749 
750 #ifdef CONFIG_UCLAMP_TASK
751 /* Number of utilization clamp buckets (shorter alias) */
752 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT
753 
754 /*
755  * Utilization clamp for a scheduling entity
756  * @value:		clamp value "assigned" to a se
757  * @bucket_id:		bucket index corresponding to the "assigned" value
758  * @active:		the se is currently refcounted in a rq's bucket
759  * @user_defined:	the requested clamp value comes from user-space
760  *
761  * The bucket_id is the index of the clamp bucket matching the clamp value
762  * which is pre-computed and stored to avoid expensive integer divisions from
763  * the fast path.
764  *
765  * The active bit is set whenever a task has got an "effective" value assigned,
766  * which can be different from the clamp value "requested" from user-space.
767  * This allows to know a task is refcounted in the rq's bucket corresponding
768  * to the "effective" bucket_id.
769  *
770  * The user_defined bit is set whenever a task has got a task-specific clamp
771  * value requested from userspace, i.e. the system defaults apply to this task
772  * just as a restriction. This allows to relax default clamps when a less
773  * restrictive task-specific value has been requested, thus allowing to
774  * implement a "nice" semantic. For example, a task running with a 20%
775  * default boost can still drop its own boosting to 0%.
776  */
777 struct uclamp_se {
778 	unsigned int value		: bits_per(SCHED_CAPACITY_SCALE);
779 	unsigned int bucket_id		: bits_per(UCLAMP_BUCKETS);
780 	unsigned int active		: 1;
781 	unsigned int user_defined	: 1;
782 };
783 #endif /* CONFIG_UCLAMP_TASK */
784 
785 union rcu_special {
786 	struct {
787 		u8			blocked;
788 		u8			need_qs;
789 		u8			exp_hint; /* Hint for performance. */
790 		u8			need_mb; /* Readers need smp_mb(). */
791 	} b; /* Bits. */
792 	u32 s; /* Set of bits. */
793 };
794 
795 enum perf_event_task_context {
796 	perf_invalid_context = -1,
797 	perf_hw_context = 0,
798 	perf_sw_context,
799 	perf_nr_task_contexts,
800 };
801 
802 /*
803  * Number of contexts where an event can trigger:
804  *      task, softirq, hardirq, nmi.
805  */
806 #define PERF_NR_CONTEXTS	4
807 
808 struct wake_q_node {
809 	struct wake_q_node *next;
810 };
811 
812 struct kmap_ctrl {
813 #ifdef CONFIG_KMAP_LOCAL
814 	int				idx;
815 	pte_t				pteval[KM_MAX_IDX];
816 #endif
817 };
818 
819 struct task_struct {
820 #ifdef CONFIG_THREAD_INFO_IN_TASK
821 	/*
822 	 * For reasons of header soup (see current_thread_info()), this
823 	 * must be the first element of task_struct.
824 	 */
825 	struct thread_info		thread_info;
826 #endif
827 	unsigned int			__state;
828 
829 	/* saved state for "spinlock sleepers" */
830 	unsigned int			saved_state;
831 
832 	/*
833 	 * This begins the randomizable portion of task_struct. Only
834 	 * scheduling-critical items should be added above here.
835 	 */
836 	randomized_struct_fields_start
837 
838 	void				*stack;
839 	refcount_t			usage;
840 	/* Per task flags (PF_*), defined further below: */
841 	unsigned int			flags;
842 	unsigned int			ptrace;
843 
844 #ifdef CONFIG_MEM_ALLOC_PROFILING
845 	struct alloc_tag		*alloc_tag;
846 #endif
847 
848 	int				on_cpu;
849 	struct __call_single_node	wake_entry;
850 	unsigned int			wakee_flips;
851 	unsigned long			wakee_flip_decay_ts;
852 	struct task_struct		*last_wakee;
853 
854 	/*
855 	 * recent_used_cpu is initially set as the last CPU used by a task
856 	 * that wakes affine another task. Waker/wakee relationships can
857 	 * push tasks around a CPU where each wakeup moves to the next one.
858 	 * Tracking a recently used CPU allows a quick search for a recently
859 	 * used CPU that may be idle.
860 	 */
861 	int				recent_used_cpu;
862 	int				wake_cpu;
863 	int				on_rq;
864 
865 	int				prio;
866 	int				static_prio;
867 	int				normal_prio;
868 	unsigned int			rt_priority;
869 
870 	struct sched_entity		se;
871 	struct sched_rt_entity		rt;
872 	struct sched_dl_entity		dl;
873 	struct sched_dl_entity		*dl_server;
874 #ifdef CONFIG_SCHED_CLASS_EXT
875 	struct sched_ext_entity		scx;
876 #endif
877 	const struct sched_class	*sched_class;
878 
879 #ifdef CONFIG_SCHED_CORE
880 	struct rb_node			core_node;
881 	unsigned long			core_cookie;
882 	unsigned int			core_occupation;
883 #endif
884 
885 #ifdef CONFIG_CGROUP_SCHED
886 	struct task_group		*sched_task_group;
887 #ifdef CONFIG_CFS_BANDWIDTH
888 	struct callback_head		sched_throttle_work;
889 	struct list_head		throttle_node;
890 	bool				throttled;
891 #endif
892 #endif
893 
894 
895 #ifdef CONFIG_UCLAMP_TASK
896 	/*
897 	 * Clamp values requested for a scheduling entity.
898 	 * Must be updated with task_rq_lock() held.
899 	 */
900 	struct uclamp_se		uclamp_req[UCLAMP_CNT];
901 	/*
902 	 * Effective clamp values used for a scheduling entity.
903 	 * Must be updated with task_rq_lock() held.
904 	 */
905 	struct uclamp_se		uclamp[UCLAMP_CNT];
906 #endif
907 
908 	struct sched_statistics         stats;
909 
910 #ifdef CONFIG_PREEMPT_NOTIFIERS
911 	/* List of struct preempt_notifier: */
912 	struct hlist_head		preempt_notifiers;
913 #endif
914 
915 #ifdef CONFIG_BLK_DEV_IO_TRACE
916 	unsigned int			btrace_seq;
917 #endif
918 
919 	unsigned int			policy;
920 	unsigned long			max_allowed_capacity;
921 	int				nr_cpus_allowed;
922 	const cpumask_t			*cpus_ptr;
923 	cpumask_t			*user_cpus_ptr;
924 	cpumask_t			cpus_mask;
925 	void				*migration_pending;
926 	unsigned short			migration_disabled;
927 	unsigned short			migration_flags;
928 
929 #ifdef CONFIG_PREEMPT_RCU
930 	int				rcu_read_lock_nesting;
931 	union rcu_special		rcu_read_unlock_special;
932 	struct list_head		rcu_node_entry;
933 	struct rcu_node			*rcu_blocked_node;
934 #endif /* #ifdef CONFIG_PREEMPT_RCU */
935 
936 #ifdef CONFIG_TASKS_RCU
937 	unsigned long			rcu_tasks_nvcsw;
938 	u8				rcu_tasks_holdout;
939 	u8				rcu_tasks_idx;
940 	int				rcu_tasks_idle_cpu;
941 	struct list_head		rcu_tasks_holdout_list;
942 	int				rcu_tasks_exit_cpu;
943 	struct list_head		rcu_tasks_exit_list;
944 #endif /* #ifdef CONFIG_TASKS_RCU */
945 
946 #ifdef CONFIG_TASKS_TRACE_RCU
947 	int				trc_reader_nesting;
948 	int				trc_ipi_to_cpu;
949 	union rcu_special		trc_reader_special;
950 	struct list_head		trc_holdout_list;
951 	struct list_head		trc_blkd_node;
952 	int				trc_blkd_cpu;
953 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
954 
955 	struct sched_info		sched_info;
956 
957 	struct list_head		tasks;
958 	struct plist_node		pushable_tasks;
959 	struct rb_node			pushable_dl_tasks;
960 
961 	struct mm_struct		*mm;
962 	struct mm_struct		*active_mm;
963 	struct address_space		*faults_disabled_mapping;
964 
965 	int				exit_state;
966 	int				exit_code;
967 	int				exit_signal;
968 	/* The signal sent when the parent dies: */
969 	int				pdeath_signal;
970 	/* JOBCTL_*, siglock protected: */
971 	unsigned long			jobctl;
972 
973 	/* Used for emulating ABI behavior of previous Linux versions: */
974 	unsigned int			personality;
975 
976 	/* Scheduler bits, serialized by scheduler locks: */
977 	unsigned			sched_reset_on_fork:1;
978 	unsigned			sched_contributes_to_load:1;
979 	unsigned			sched_migrated:1;
980 	unsigned			sched_task_hot:1;
981 
982 	/* Force alignment to the next boundary: */
983 	unsigned			:0;
984 
985 	/* Unserialized, strictly 'current' */
986 
987 	/*
988 	 * This field must not be in the scheduler word above due to wakelist
989 	 * queueing no longer being serialized by p->on_cpu. However:
990 	 *
991 	 * p->XXX = X;			ttwu()
992 	 * schedule()			  if (p->on_rq && ..) // false
993 	 *   smp_mb__after_spinlock();	  if (smp_load_acquire(&p->on_cpu) && //true
994 	 *   deactivate_task()		      ttwu_queue_wakelist())
995 	 *     p->on_rq = 0;			p->sched_remote_wakeup = Y;
996 	 *
997 	 * guarantees all stores of 'current' are visible before
998 	 * ->sched_remote_wakeup gets used, so it can be in this word.
999 	 */
1000 	unsigned			sched_remote_wakeup:1;
1001 #ifdef CONFIG_RT_MUTEXES
1002 	unsigned			sched_rt_mutex:1;
1003 #endif
1004 
1005 	/* Bit to tell TOMOYO we're in execve(): */
1006 	unsigned			in_execve:1;
1007 	unsigned			in_iowait:1;
1008 #ifndef TIF_RESTORE_SIGMASK
1009 	unsigned			restore_sigmask:1;
1010 #endif
1011 #ifdef CONFIG_MEMCG_V1
1012 	unsigned			in_user_fault:1;
1013 #endif
1014 #ifdef CONFIG_LRU_GEN
1015 	/* whether the LRU algorithm may apply to this access */
1016 	unsigned			in_lru_fault:1;
1017 #endif
1018 #ifdef CONFIG_COMPAT_BRK
1019 	unsigned			brk_randomized:1;
1020 #endif
1021 #ifdef CONFIG_CGROUPS
1022 	/* disallow userland-initiated cgroup migration */
1023 	unsigned			no_cgroup_migration:1;
1024 	/* task is frozen/stopped (used by the cgroup freezer) */
1025 	unsigned			frozen:1;
1026 #endif
1027 #ifdef CONFIG_BLK_CGROUP
1028 	unsigned			use_memdelay:1;
1029 #endif
1030 #ifdef CONFIG_PSI
1031 	/* Stalled due to lack of memory */
1032 	unsigned			in_memstall:1;
1033 #endif
1034 #ifdef CONFIG_PAGE_OWNER
1035 	/* Used by page_owner=on to detect recursion in page tracking. */
1036 	unsigned			in_page_owner:1;
1037 #endif
1038 #ifdef CONFIG_EVENTFD
1039 	/* Recursion prevention for eventfd_signal() */
1040 	unsigned			in_eventfd:1;
1041 #endif
1042 #ifdef CONFIG_ARCH_HAS_CPU_PASID
1043 	unsigned			pasid_activated:1;
1044 #endif
1045 #ifdef CONFIG_X86_BUS_LOCK_DETECT
1046 	unsigned			reported_split_lock:1;
1047 #endif
1048 #ifdef CONFIG_TASK_DELAY_ACCT
1049 	/* delay due to memory thrashing */
1050 	unsigned                        in_thrashing:1;
1051 #endif
1052 	unsigned			in_nf_duplicate:1;
1053 #ifdef CONFIG_PREEMPT_RT
1054 	struct netdev_xmit		net_xmit;
1055 #endif
1056 	unsigned long			atomic_flags; /* Flags requiring atomic access. */
1057 
1058 	struct restart_block		restart_block;
1059 
1060 	pid_t				pid;
1061 	pid_t				tgid;
1062 
1063 #ifdef CONFIG_STACKPROTECTOR
1064 	/* Canary value for the -fstack-protector GCC feature: */
1065 	unsigned long			stack_canary;
1066 #endif
1067 	/*
1068 	 * Pointers to the (original) parent process, youngest child, younger sibling,
1069 	 * older sibling, respectively.  (p->father can be replaced with
1070 	 * p->real_parent->pid)
1071 	 */
1072 
1073 	/* Real parent process: */
1074 	struct task_struct __rcu	*real_parent;
1075 
1076 	/* Recipient of SIGCHLD, wait4() reports: */
1077 	struct task_struct __rcu	*parent;
1078 
1079 	/*
1080 	 * Children/sibling form the list of natural children:
1081 	 */
1082 	struct list_head		children;
1083 	struct list_head		sibling;
1084 	struct task_struct		*group_leader;
1085 
1086 	/*
1087 	 * 'ptraced' is the list of tasks this task is using ptrace() on.
1088 	 *
1089 	 * This includes both natural children and PTRACE_ATTACH targets.
1090 	 * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
1091 	 */
1092 	struct list_head		ptraced;
1093 	struct list_head		ptrace_entry;
1094 
1095 	/* PID/PID hash table linkage. */
1096 	struct pid			*thread_pid;
1097 	struct hlist_node		pid_links[PIDTYPE_MAX];
1098 	struct list_head		thread_node;
1099 
1100 	struct completion		*vfork_done;
1101 
1102 	/* CLONE_CHILD_SETTID: */
1103 	int __user			*set_child_tid;
1104 
1105 	/* CLONE_CHILD_CLEARTID: */
1106 	int __user			*clear_child_tid;
1107 
1108 	/* PF_KTHREAD | PF_IO_WORKER */
1109 	void				*worker_private;
1110 
1111 	u64				utime;
1112 	u64				stime;
1113 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
1114 	u64				utimescaled;
1115 	u64				stimescaled;
1116 #endif
1117 	u64				gtime;
1118 	struct prev_cputime		prev_cputime;
1119 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1120 	struct vtime			vtime;
1121 #endif
1122 
1123 #ifdef CONFIG_NO_HZ_FULL
1124 	atomic_t			tick_dep_mask;
1125 #endif
1126 	/* Context switch counts: */
1127 	unsigned long			nvcsw;
1128 	unsigned long			nivcsw;
1129 
1130 	/* Monotonic time in nsecs: */
1131 	u64				start_time;
1132 
1133 	/* Boot based time in nsecs: */
1134 	u64				start_boottime;
1135 
1136 	/* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
1137 	unsigned long			min_flt;
1138 	unsigned long			maj_flt;
1139 
1140 	/* Empty if CONFIG_POSIX_CPUTIMERS=n */
1141 	struct posix_cputimers		posix_cputimers;
1142 
1143 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK
1144 	struct posix_cputimers_work	posix_cputimers_work;
1145 #endif
1146 
1147 	/* Process credentials: */
1148 
1149 	/* Tracer's credentials at attach: */
1150 	const struct cred __rcu		*ptracer_cred;
1151 
1152 	/* Objective and real subjective task credentials (COW): */
1153 	const struct cred __rcu		*real_cred;
1154 
1155 	/* Effective (overridable) subjective task credentials (COW): */
1156 	const struct cred __rcu		*cred;
1157 
1158 #ifdef CONFIG_KEYS
1159 	/* Cached requested key. */
1160 	struct key			*cached_requested_key;
1161 #endif
1162 
1163 	/*
1164 	 * executable name, excluding path.
1165 	 *
1166 	 * - normally initialized begin_new_exec()
1167 	 * - set it with set_task_comm()
1168 	 *   - strscpy_pad() to ensure it is always NUL-terminated and
1169 	 *     zero-padded
1170 	 *   - task_lock() to ensure the operation is atomic and the name is
1171 	 *     fully updated.
1172 	 */
1173 	char				comm[TASK_COMM_LEN];
1174 
1175 	struct nameidata		*nameidata;
1176 
1177 #ifdef CONFIG_SYSVIPC
1178 	struct sysv_sem			sysvsem;
1179 	struct sysv_shm			sysvshm;
1180 #endif
1181 #ifdef CONFIG_DETECT_HUNG_TASK
1182 	unsigned long			last_switch_count;
1183 	unsigned long			last_switch_time;
1184 #endif
1185 	/* Filesystem information: */
1186 	struct fs_struct		*fs;
1187 
1188 	/* Open file information: */
1189 	struct files_struct		*files;
1190 
1191 #ifdef CONFIG_IO_URING
1192 	struct io_uring_task		*io_uring;
1193 #endif
1194 
1195 	/* Namespaces: */
1196 	struct nsproxy			*nsproxy;
1197 
1198 	/* Signal handlers: */
1199 	struct signal_struct		*signal;
1200 	struct sighand_struct __rcu		*sighand;
1201 	sigset_t			blocked;
1202 	sigset_t			real_blocked;
1203 	/* Restored if set_restore_sigmask() was used: */
1204 	sigset_t			saved_sigmask;
1205 	struct sigpending		pending;
1206 	unsigned long			sas_ss_sp;
1207 	size_t				sas_ss_size;
1208 	unsigned int			sas_ss_flags;
1209 
1210 	struct callback_head		*task_works;
1211 
1212 #ifdef CONFIG_AUDIT
1213 #ifdef CONFIG_AUDITSYSCALL
1214 	struct audit_context		*audit_context;
1215 #endif
1216 	kuid_t				loginuid;
1217 	unsigned int			sessionid;
1218 #endif
1219 	struct seccomp			seccomp;
1220 	struct syscall_user_dispatch	syscall_dispatch;
1221 
1222 	/* Thread group tracking: */
1223 	u64				parent_exec_id;
1224 	u64				self_exec_id;
1225 
1226 	/* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
1227 	spinlock_t			alloc_lock;
1228 
1229 	/* Protection of the PI data structures: */
1230 	raw_spinlock_t			pi_lock;
1231 
1232 	struct wake_q_node		wake_q;
1233 
1234 #ifdef CONFIG_RT_MUTEXES
1235 	/* PI waiters blocked on a rt_mutex held by this task: */
1236 	struct rb_root_cached		pi_waiters;
1237 	/* Updated under owner's pi_lock and rq lock */
1238 	struct task_struct		*pi_top_task;
1239 	/* Deadlock detection and priority inheritance handling: */
1240 	struct rt_mutex_waiter		*pi_blocked_on;
1241 #endif
1242 
1243 	struct mutex			*blocked_on;	/* lock we're blocked on */
1244 
1245 #ifdef CONFIG_DETECT_HUNG_TASK_BLOCKER
1246 	/*
1247 	 * Encoded lock address causing task block (lower 2 bits = type from
1248 	 * <linux/hung_task.h>). Accessed via hung_task_*() helpers.
1249 	 */
1250 	unsigned long			blocker;
1251 #endif
1252 
1253 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1254 	int				non_block_count;
1255 #endif
1256 
1257 #ifdef CONFIG_TRACE_IRQFLAGS
1258 	struct irqtrace_events		irqtrace;
1259 	unsigned int			hardirq_threaded;
1260 	u64				hardirq_chain_key;
1261 	int				softirqs_enabled;
1262 	int				softirq_context;
1263 	int				irq_config;
1264 #endif
1265 #ifdef CONFIG_PREEMPT_RT
1266 	int				softirq_disable_cnt;
1267 #endif
1268 
1269 #ifdef CONFIG_LOCKDEP
1270 # define MAX_LOCK_DEPTH			48UL
1271 	u64				curr_chain_key;
1272 	int				lockdep_depth;
1273 	unsigned int			lockdep_recursion;
1274 	struct held_lock		held_locks[MAX_LOCK_DEPTH];
1275 #endif
1276 
1277 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP)
1278 	unsigned int			in_ubsan;
1279 #endif
1280 
1281 	/* Journalling filesystem info: */
1282 	void				*journal_info;
1283 
1284 	/* Stacked block device info: */
1285 	struct bio_list			*bio_list;
1286 
1287 	/* Stack plugging: */
1288 	struct blk_plug			*plug;
1289 
1290 	/* VM state: */
1291 	struct reclaim_state		*reclaim_state;
1292 
1293 	struct io_context		*io_context;
1294 
1295 #ifdef CONFIG_COMPACTION
1296 	struct capture_control		*capture_control;
1297 #endif
1298 	/* Ptrace state: */
1299 	unsigned long			ptrace_message;
1300 	kernel_siginfo_t		*last_siginfo;
1301 
1302 	struct task_io_accounting	ioac;
1303 #ifdef CONFIG_PSI
1304 	/* Pressure stall state */
1305 	unsigned int			psi_flags;
1306 #endif
1307 #ifdef CONFIG_TASK_XACCT
1308 	/* Accumulated RSS usage: */
1309 	u64				acct_rss_mem1;
1310 	/* Accumulated virtual memory usage: */
1311 	u64				acct_vm_mem1;
1312 	/* stime + utime since last update: */
1313 	u64				acct_timexpd;
1314 #endif
1315 #ifdef CONFIG_CPUSETS
1316 	/* Protected by ->alloc_lock: */
1317 	nodemask_t			mems_allowed;
1318 	/* Sequence number to catch updates: */
1319 	seqcount_spinlock_t		mems_allowed_seq;
1320 	int				cpuset_mem_spread_rotor;
1321 #endif
1322 #ifdef CONFIG_CGROUPS
1323 	/* Control Group info protected by css_set_lock: */
1324 	struct css_set __rcu		*cgroups;
1325 	/* cg_list protected by css_set_lock and tsk->alloc_lock: */
1326 	struct list_head		cg_list;
1327 #endif
1328 #ifdef CONFIG_X86_CPU_RESCTRL
1329 	u32				closid;
1330 	u32				rmid;
1331 #endif
1332 #ifdef CONFIG_FUTEX
1333 	struct robust_list_head __user	*robust_list;
1334 #ifdef CONFIG_COMPAT
1335 	struct compat_robust_list_head __user *compat_robust_list;
1336 #endif
1337 	struct list_head		pi_state_list;
1338 	struct futex_pi_state		*pi_state_cache;
1339 	struct mutex			futex_exit_mutex;
1340 	unsigned int			futex_state;
1341 #endif
1342 #ifdef CONFIG_PERF_EVENTS
1343 	u8				perf_recursion[PERF_NR_CONTEXTS];
1344 	struct perf_event_context	*perf_event_ctxp;
1345 	struct mutex			perf_event_mutex;
1346 	struct list_head		perf_event_list;
1347 	struct perf_ctx_data __rcu	*perf_ctx_data;
1348 #endif
1349 #ifdef CONFIG_DEBUG_PREEMPT
1350 	unsigned long			preempt_disable_ip;
1351 #endif
1352 #ifdef CONFIG_NUMA
1353 	/* Protected by alloc_lock: */
1354 	struct mempolicy		*mempolicy;
1355 	short				il_prev;
1356 	u8				il_weight;
1357 	short				pref_node_fork;
1358 #endif
1359 #ifdef CONFIG_NUMA_BALANCING
1360 	int				numa_scan_seq;
1361 	unsigned int			numa_scan_period;
1362 	unsigned int			numa_scan_period_max;
1363 	int				numa_preferred_nid;
1364 	unsigned long			numa_migrate_retry;
1365 	/* Migration stamp: */
1366 	u64				node_stamp;
1367 	u64				last_task_numa_placement;
1368 	u64				last_sum_exec_runtime;
1369 	struct callback_head		numa_work;
1370 
1371 	/*
1372 	 * This pointer is only modified for current in syscall and
1373 	 * pagefault context (and for tasks being destroyed), so it can be read
1374 	 * from any of the following contexts:
1375 	 *  - RCU read-side critical section
1376 	 *  - current->numa_group from everywhere
1377 	 *  - task's runqueue locked, task not running
1378 	 */
1379 	struct numa_group __rcu		*numa_group;
1380 
1381 	/*
1382 	 * numa_faults is an array split into four regions:
1383 	 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1384 	 * in this precise order.
1385 	 *
1386 	 * faults_memory: Exponential decaying average of faults on a per-node
1387 	 * basis. Scheduling placement decisions are made based on these
1388 	 * counts. The values remain static for the duration of a PTE scan.
1389 	 * faults_cpu: Track the nodes the process was running on when a NUMA
1390 	 * hinting fault was incurred.
1391 	 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1392 	 * during the current scan window. When the scan completes, the counts
1393 	 * in faults_memory and faults_cpu decay and these values are copied.
1394 	 */
1395 	unsigned long			*numa_faults;
1396 	unsigned long			total_numa_faults;
1397 
1398 	/*
1399 	 * numa_faults_locality tracks if faults recorded during the last
1400 	 * scan window were remote/local or failed to migrate. The task scan
1401 	 * period is adapted based on the locality of the faults with different
1402 	 * weights depending on whether they were shared or private faults
1403 	 */
1404 	unsigned long			numa_faults_locality[3];
1405 
1406 	unsigned long			numa_pages_migrated;
1407 #endif /* CONFIG_NUMA_BALANCING */
1408 
1409 #ifdef CONFIG_RSEQ
1410 	struct rseq __user *rseq;
1411 	u32 rseq_len;
1412 	u32 rseq_sig;
1413 	/*
1414 	 * RmW on rseq_event_mask must be performed atomically
1415 	 * with respect to preemption.
1416 	 */
1417 	unsigned long rseq_event_mask;
1418 # ifdef CONFIG_DEBUG_RSEQ
1419 	/*
1420 	 * This is a place holder to save a copy of the rseq fields for
1421 	 * validation of read-only fields. The struct rseq has a
1422 	 * variable-length array at the end, so it cannot be used
1423 	 * directly. Reserve a size large enough for the known fields.
1424 	 */
1425 	char				rseq_fields[sizeof(struct rseq)];
1426 # endif
1427 #endif
1428 
1429 #ifdef CONFIG_SCHED_MM_CID
1430 	int				mm_cid;		/* Current cid in mm */
1431 	int				last_mm_cid;	/* Most recent cid in mm */
1432 	int				migrate_from_cpu;
1433 	int				mm_cid_active;	/* Whether cid bitmap is active */
1434 	struct callback_head		cid_work;
1435 #endif
1436 
1437 	struct tlbflush_unmap_batch	tlb_ubc;
1438 
1439 	/* Cache last used pipe for splice(): */
1440 	struct pipe_inode_info		*splice_pipe;
1441 
1442 	struct page_frag		task_frag;
1443 
1444 #ifdef CONFIG_TASK_DELAY_ACCT
1445 	struct task_delay_info		*delays;
1446 #endif
1447 
1448 #ifdef CONFIG_FAULT_INJECTION
1449 	int				make_it_fail;
1450 	unsigned int			fail_nth;
1451 #endif
1452 	/*
1453 	 * When (nr_dirtied >= nr_dirtied_pause), it's time to call
1454 	 * balance_dirty_pages() for a dirty throttling pause:
1455 	 */
1456 	int				nr_dirtied;
1457 	int				nr_dirtied_pause;
1458 	/* Start of a write-and-pause period: */
1459 	unsigned long			dirty_paused_when;
1460 
1461 #ifdef CONFIG_LATENCYTOP
1462 	int				latency_record_count;
1463 	struct latency_record		latency_record[LT_SAVECOUNT];
1464 #endif
1465 	/*
1466 	 * Time slack values; these are used to round up poll() and
1467 	 * select() etc timeout values. These are in nanoseconds.
1468 	 */
1469 	u64				timer_slack_ns;
1470 	u64				default_timer_slack_ns;
1471 
1472 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
1473 	unsigned int			kasan_depth;
1474 #endif
1475 
1476 #ifdef CONFIG_KCSAN
1477 	struct kcsan_ctx		kcsan_ctx;
1478 #ifdef CONFIG_TRACE_IRQFLAGS
1479 	struct irqtrace_events		kcsan_save_irqtrace;
1480 #endif
1481 #ifdef CONFIG_KCSAN_WEAK_MEMORY
1482 	int				kcsan_stack_depth;
1483 #endif
1484 #endif
1485 
1486 #ifdef CONFIG_KMSAN
1487 	struct kmsan_ctx		kmsan_ctx;
1488 #endif
1489 
1490 #if IS_ENABLED(CONFIG_KUNIT)
1491 	struct kunit			*kunit_test;
1492 #endif
1493 
1494 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1495 	/* Index of current stored address in ret_stack: */
1496 	int				curr_ret_stack;
1497 	int				curr_ret_depth;
1498 
1499 	/* Stack of return addresses for return function tracing: */
1500 	unsigned long			*ret_stack;
1501 
1502 	/* Timestamp for last schedule: */
1503 	unsigned long long		ftrace_timestamp;
1504 	unsigned long long		ftrace_sleeptime;
1505 
1506 	/*
1507 	 * Number of functions that haven't been traced
1508 	 * because of depth overrun:
1509 	 */
1510 	atomic_t			trace_overrun;
1511 
1512 	/* Pause tracing: */
1513 	atomic_t			tracing_graph_pause;
1514 #endif
1515 
1516 #ifdef CONFIG_TRACING
1517 	/* Bitmask and counter of trace recursion: */
1518 	unsigned long			trace_recursion;
1519 #endif /* CONFIG_TRACING */
1520 
1521 #ifdef CONFIG_KCOV
1522 	/* See kernel/kcov.c for more details. */
1523 
1524 	/* Coverage collection mode enabled for this task (0 if disabled): */
1525 	unsigned int			kcov_mode;
1526 
1527 	/* Size of the kcov_area: */
1528 	unsigned int			kcov_size;
1529 
1530 	/* Buffer for coverage collection: */
1531 	void				*kcov_area;
1532 
1533 	/* KCOV descriptor wired with this task or NULL: */
1534 	struct kcov			*kcov;
1535 
1536 	/* KCOV common handle for remote coverage collection: */
1537 	u64				kcov_handle;
1538 
1539 	/* KCOV sequence number: */
1540 	int				kcov_sequence;
1541 
1542 	/* Collect coverage from softirq context: */
1543 	unsigned int			kcov_softirq;
1544 #endif
1545 
1546 #ifdef CONFIG_MEMCG_V1
1547 	struct mem_cgroup		*memcg_in_oom;
1548 #endif
1549 
1550 #ifdef CONFIG_MEMCG
1551 	/* Number of pages to reclaim on returning to userland: */
1552 	unsigned int			memcg_nr_pages_over_high;
1553 
1554 	/* Used by memcontrol for targeted memcg charge: */
1555 	struct mem_cgroup		*active_memcg;
1556 
1557 	/* Cache for current->cgroups->memcg->objcg lookups: */
1558 	struct obj_cgroup		*objcg;
1559 #endif
1560 
1561 #ifdef CONFIG_BLK_CGROUP
1562 	struct gendisk			*throttle_disk;
1563 #endif
1564 
1565 #ifdef CONFIG_UPROBES
1566 	struct uprobe_task		*utask;
1567 #endif
1568 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1569 	unsigned int			sequential_io;
1570 	unsigned int			sequential_io_avg;
1571 #endif
1572 	struct kmap_ctrl		kmap_ctrl;
1573 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1574 	unsigned long			task_state_change;
1575 # ifdef CONFIG_PREEMPT_RT
1576 	unsigned long			saved_state_change;
1577 # endif
1578 #endif
1579 	struct rcu_head			rcu;
1580 	refcount_t			rcu_users;
1581 	int				pagefault_disabled;
1582 #ifdef CONFIG_MMU
1583 	struct task_struct		*oom_reaper_list;
1584 	struct timer_list		oom_reaper_timer;
1585 #endif
1586 #ifdef CONFIG_VMAP_STACK
1587 	struct vm_struct		*stack_vm_area;
1588 #endif
1589 #ifdef CONFIG_THREAD_INFO_IN_TASK
1590 	/* A live task holds one reference: */
1591 	refcount_t			stack_refcount;
1592 #endif
1593 #ifdef CONFIG_LIVEPATCH
1594 	int patch_state;
1595 #endif
1596 #ifdef CONFIG_SECURITY
1597 	/* Used by LSM modules for access restriction: */
1598 	void				*security;
1599 #endif
1600 #ifdef CONFIG_BPF_SYSCALL
1601 	/* Used by BPF task local storage */
1602 	struct bpf_local_storage __rcu	*bpf_storage;
1603 	/* Used for BPF run context */
1604 	struct bpf_run_ctx		*bpf_ctx;
1605 #endif
1606 	/* Used by BPF for per-TASK xdp storage */
1607 	struct bpf_net_context		*bpf_net_context;
1608 
1609 #ifdef CONFIG_KSTACK_ERASE
1610 	unsigned long			lowest_stack;
1611 #endif
1612 #ifdef CONFIG_KSTACK_ERASE_METRICS
1613 	unsigned long			prev_lowest_stack;
1614 #endif
1615 
1616 #ifdef CONFIG_X86_MCE
1617 	void __user			*mce_vaddr;
1618 	__u64				mce_kflags;
1619 	u64				mce_addr;
1620 	__u64				mce_ripv : 1,
1621 					mce_whole_page : 1,
1622 					__mce_reserved : 62;
1623 	struct callback_head		mce_kill_me;
1624 	int				mce_count;
1625 #endif
1626 
1627 #ifdef CONFIG_KRETPROBES
1628 	struct llist_head               kretprobe_instances;
1629 #endif
1630 #ifdef CONFIG_RETHOOK
1631 	struct llist_head               rethooks;
1632 #endif
1633 
1634 #ifdef CONFIG_ARCH_HAS_PARANOID_L1D_FLUSH
1635 	/*
1636 	 * If L1D flush is supported on mm context switch
1637 	 * then we use this callback head to queue kill work
1638 	 * to kill tasks that are not running on SMT disabled
1639 	 * cores
1640 	 */
1641 	struct callback_head		l1d_flush_kill;
1642 #endif
1643 
1644 #ifdef CONFIG_RV
1645 	/*
1646 	 * Per-task RV monitor, fixed in CONFIG_RV_PER_TASK_MONITORS.
1647 	 * If memory becomes a concern, we can think about a dynamic method.
1648 	 */
1649 	union rv_task_monitor		rv[CONFIG_RV_PER_TASK_MONITORS];
1650 #endif
1651 
1652 #ifdef CONFIG_USER_EVENTS
1653 	struct user_event_mm		*user_event_mm;
1654 #endif
1655 
1656 #ifdef CONFIG_UNWIND_USER
1657 	struct unwind_task_info		unwind_info;
1658 #endif
1659 
1660 	/* CPU-specific state of this task: */
1661 	struct thread_struct		thread;
1662 
1663 	/*
1664 	 * New fields for task_struct should be added above here, so that
1665 	 * they are included in the randomized portion of task_struct.
1666 	 */
1667 	randomized_struct_fields_end
1668 } __attribute__ ((aligned (64)));
1669 
1670 #ifdef CONFIG_SCHED_PROXY_EXEC
1671 DECLARE_STATIC_KEY_TRUE(__sched_proxy_exec);
sched_proxy_exec(void)1672 static inline bool sched_proxy_exec(void)
1673 {
1674 	return static_branch_likely(&__sched_proxy_exec);
1675 }
1676 #else
sched_proxy_exec(void)1677 static inline bool sched_proxy_exec(void)
1678 {
1679 	return false;
1680 }
1681 #endif
1682 
1683 #define TASK_REPORT_IDLE	(TASK_REPORT + 1)
1684 #define TASK_REPORT_MAX		(TASK_REPORT_IDLE << 1)
1685 
__task_state_index(unsigned int tsk_state,unsigned int tsk_exit_state)1686 static inline unsigned int __task_state_index(unsigned int tsk_state,
1687 					      unsigned int tsk_exit_state)
1688 {
1689 	unsigned int state = (tsk_state | tsk_exit_state) & TASK_REPORT;
1690 
1691 	BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX);
1692 
1693 	if ((tsk_state & TASK_IDLE) == TASK_IDLE)
1694 		state = TASK_REPORT_IDLE;
1695 
1696 	/*
1697 	 * We're lying here, but rather than expose a completely new task state
1698 	 * to userspace, we can make this appear as if the task has gone through
1699 	 * a regular rt_mutex_lock() call.
1700 	 * Report frozen tasks as uninterruptible.
1701 	 */
1702 	if ((tsk_state & TASK_RTLOCK_WAIT) || (tsk_state & TASK_FROZEN))
1703 		state = TASK_UNINTERRUPTIBLE;
1704 
1705 	return fls(state);
1706 }
1707 
task_state_index(struct task_struct * tsk)1708 static inline unsigned int task_state_index(struct task_struct *tsk)
1709 {
1710 	return __task_state_index(READ_ONCE(tsk->__state), tsk->exit_state);
1711 }
1712 
task_index_to_char(unsigned int state)1713 static inline char task_index_to_char(unsigned int state)
1714 {
1715 	static const char state_char[] = "RSDTtXZPI";
1716 
1717 	BUILD_BUG_ON(TASK_REPORT_MAX * 2 != 1 << (sizeof(state_char) - 1));
1718 
1719 	return state_char[state];
1720 }
1721 
task_state_to_char(struct task_struct * tsk)1722 static inline char task_state_to_char(struct task_struct *tsk)
1723 {
1724 	return task_index_to_char(task_state_index(tsk));
1725 }
1726 
1727 extern struct pid *cad_pid;
1728 
1729 /*
1730  * Per process flags
1731  */
1732 #define PF_VCPU			0x00000001	/* I'm a virtual CPU */
1733 #define PF_IDLE			0x00000002	/* I am an IDLE thread */
1734 #define PF_EXITING		0x00000004	/* Getting shut down */
1735 #define PF_POSTCOREDUMP		0x00000008	/* Coredumps should ignore this task */
1736 #define PF_IO_WORKER		0x00000010	/* Task is an IO worker */
1737 #define PF_WQ_WORKER		0x00000020	/* I'm a workqueue worker */
1738 #define PF_FORKNOEXEC		0x00000040	/* Forked but didn't exec */
1739 #define PF_MCE_PROCESS		0x00000080      /* Process policy on mce errors */
1740 #define PF_SUPERPRIV		0x00000100	/* Used super-user privileges */
1741 #define PF_DUMPCORE		0x00000200	/* Dumped core */
1742 #define PF_SIGNALED		0x00000400	/* Killed by a signal */
1743 #define PF_MEMALLOC		0x00000800	/* Allocating memory to free memory. See memalloc_noreclaim_save() */
1744 #define PF_NPROC_EXCEEDED	0x00001000	/* set_user() noticed that RLIMIT_NPROC was exceeded */
1745 #define PF_USED_MATH		0x00002000	/* If unset the fpu must be initialized before use */
1746 #define PF_USER_WORKER		0x00004000	/* Kernel thread cloned from userspace thread */
1747 #define PF_NOFREEZE		0x00008000	/* This thread should not be frozen */
1748 #define PF_KCOMPACTD		0x00010000	/* I am kcompactd */
1749 #define PF_KSWAPD		0x00020000	/* I am kswapd */
1750 #define PF_MEMALLOC_NOFS	0x00040000	/* All allocations inherit GFP_NOFS. See memalloc_nfs_save() */
1751 #define PF_MEMALLOC_NOIO	0x00080000	/* All allocations inherit GFP_NOIO. See memalloc_noio_save() */
1752 #define PF_LOCAL_THROTTLE	0x00100000	/* Throttle writes only against the bdi I write to,
1753 						 * I am cleaning dirty pages from some other bdi. */
1754 #define PF_KTHREAD		0x00200000	/* I am a kernel thread */
1755 #define PF_RANDOMIZE		0x00400000	/* Randomize virtual address space */
1756 #define PF__HOLE__00800000	0x00800000
1757 #define PF__HOLE__01000000	0x01000000
1758 #define PF__HOLE__02000000	0x02000000
1759 #define PF_NO_SETAFFINITY	0x04000000	/* Userland is not allowed to meddle with cpus_mask */
1760 #define PF_MCE_EARLY		0x08000000      /* Early kill for mce process policy */
1761 #define PF_MEMALLOC_PIN		0x10000000	/* Allocations constrained to zones which allow long term pinning.
1762 						 * See memalloc_pin_save() */
1763 #define PF_BLOCK_TS		0x20000000	/* plug has ts that needs updating */
1764 #define PF__HOLE__40000000	0x40000000
1765 #define PF_SUSPEND_TASK		0x80000000      /* This thread called freeze_processes() and should not be frozen */
1766 
1767 /*
1768  * Only the _current_ task can read/write to tsk->flags, but other
1769  * tasks can access tsk->flags in readonly mode for example
1770  * with tsk_used_math (like during threaded core dumping).
1771  * There is however an exception to this rule during ptrace
1772  * or during fork: the ptracer task is allowed to write to the
1773  * child->flags of its traced child (same goes for fork, the parent
1774  * can write to the child->flags), because we're guaranteed the
1775  * child is not running and in turn not changing child->flags
1776  * at the same time the parent does it.
1777  */
1778 #define clear_stopped_child_used_math(child)	do { (child)->flags &= ~PF_USED_MATH; } while (0)
1779 #define set_stopped_child_used_math(child)	do { (child)->flags |= PF_USED_MATH; } while (0)
1780 #define clear_used_math()			clear_stopped_child_used_math(current)
1781 #define set_used_math()				set_stopped_child_used_math(current)
1782 
1783 #define conditional_stopped_child_used_math(condition, child) \
1784 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1785 
1786 #define conditional_used_math(condition)	conditional_stopped_child_used_math(condition, current)
1787 
1788 #define copy_to_stopped_child_used_math(child) \
1789 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1790 
1791 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1792 #define tsk_used_math(p)			((p)->flags & PF_USED_MATH)
1793 #define used_math()				tsk_used_math(current)
1794 
is_percpu_thread(void)1795 static __always_inline bool is_percpu_thread(void)
1796 {
1797 	return (current->flags & PF_NO_SETAFFINITY) &&
1798 		(current->nr_cpus_allowed  == 1);
1799 }
1800 
1801 /* Per-process atomic flags. */
1802 #define PFA_NO_NEW_PRIVS		0	/* May not gain new privileges. */
1803 #define PFA_SPREAD_PAGE			1	/* Spread page cache over cpuset */
1804 #define PFA_SPREAD_SLAB			2	/* Spread some slab caches over cpuset */
1805 #define PFA_SPEC_SSB_DISABLE		3	/* Speculative Store Bypass disabled */
1806 #define PFA_SPEC_SSB_FORCE_DISABLE	4	/* Speculative Store Bypass force disabled*/
1807 #define PFA_SPEC_IB_DISABLE		5	/* Indirect branch speculation restricted */
1808 #define PFA_SPEC_IB_FORCE_DISABLE	6	/* Indirect branch speculation permanently restricted */
1809 #define PFA_SPEC_SSB_NOEXEC		7	/* Speculative Store Bypass clear on execve() */
1810 
1811 #define TASK_PFA_TEST(name, func)					\
1812 	static inline bool task_##func(struct task_struct *p)		\
1813 	{ return test_bit(PFA_##name, &p->atomic_flags); }
1814 
1815 #define TASK_PFA_SET(name, func)					\
1816 	static inline void task_set_##func(struct task_struct *p)	\
1817 	{ set_bit(PFA_##name, &p->atomic_flags); }
1818 
1819 #define TASK_PFA_CLEAR(name, func)					\
1820 	static inline void task_clear_##func(struct task_struct *p)	\
1821 	{ clear_bit(PFA_##name, &p->atomic_flags); }
1822 
TASK_PFA_TEST(NO_NEW_PRIVS,no_new_privs)1823 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
1824 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
1825 
1826 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
1827 TASK_PFA_SET(SPREAD_PAGE, spread_page)
1828 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
1829 
1830 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
1831 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
1832 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
1833 
1834 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable)
1835 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable)
1836 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable)
1837 
1838 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1839 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1840 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1841 
1842 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1843 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1844 
1845 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable)
1846 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable)
1847 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable)
1848 
1849 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1850 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1851 
1852 static inline void
1853 current_restore_flags(unsigned long orig_flags, unsigned long flags)
1854 {
1855 	current->flags &= ~flags;
1856 	current->flags |= orig_flags & flags;
1857 }
1858 
1859 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
1860 extern int task_can_attach(struct task_struct *p);
1861 extern int dl_bw_alloc(int cpu, u64 dl_bw);
1862 extern void dl_bw_free(int cpu, u64 dl_bw);
1863 
1864 /* do_set_cpus_allowed() - consider using set_cpus_allowed_ptr() instead */
1865 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
1866 
1867 /**
1868  * set_cpus_allowed_ptr - set CPU affinity mask of a task
1869  * @p: the task
1870  * @new_mask: CPU affinity mask
1871  *
1872  * Return: zero if successful, or a negative error code
1873  */
1874 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
1875 extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node);
1876 extern void release_user_cpus_ptr(struct task_struct *p);
1877 extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask);
1878 extern void force_compatible_cpus_allowed_ptr(struct task_struct *p);
1879 extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p);
1880 
1881 extern int yield_to(struct task_struct *p, bool preempt);
1882 extern void set_user_nice(struct task_struct *p, long nice);
1883 extern int task_prio(const struct task_struct *p);
1884 
1885 /**
1886  * task_nice - return the nice value of a given task.
1887  * @p: the task in question.
1888  *
1889  * Return: The nice value [ -20 ... 0 ... 19 ].
1890  */
task_nice(const struct task_struct * p)1891 static inline int task_nice(const struct task_struct *p)
1892 {
1893 	return PRIO_TO_NICE((p)->static_prio);
1894 }
1895 
1896 extern int can_nice(const struct task_struct *p, const int nice);
1897 extern int task_curr(const struct task_struct *p);
1898 extern int idle_cpu(int cpu);
1899 extern int available_idle_cpu(int cpu);
1900 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *);
1901 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *);
1902 extern void sched_set_fifo(struct task_struct *p);
1903 extern void sched_set_fifo_low(struct task_struct *p);
1904 extern void sched_set_normal(struct task_struct *p, int nice);
1905 extern int sched_setattr(struct task_struct *, const struct sched_attr *);
1906 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *);
1907 extern struct task_struct *idle_task(int cpu);
1908 
1909 /**
1910  * is_idle_task - is the specified task an idle task?
1911  * @p: the task in question.
1912  *
1913  * Return: 1 if @p is an idle task. 0 otherwise.
1914  */
is_idle_task(const struct task_struct * p)1915 static __always_inline bool is_idle_task(const struct task_struct *p)
1916 {
1917 	return !!(p->flags & PF_IDLE);
1918 }
1919 
1920 extern struct task_struct *curr_task(int cpu);
1921 extern void ia64_set_curr_task(int cpu, struct task_struct *p);
1922 
1923 void yield(void);
1924 
1925 union thread_union {
1926 	struct task_struct task;
1927 #ifndef CONFIG_THREAD_INFO_IN_TASK
1928 	struct thread_info thread_info;
1929 #endif
1930 	unsigned long stack[THREAD_SIZE/sizeof(long)];
1931 };
1932 
1933 #ifndef CONFIG_THREAD_INFO_IN_TASK
1934 extern struct thread_info init_thread_info;
1935 #endif
1936 
1937 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
1938 
1939 #ifdef CONFIG_THREAD_INFO_IN_TASK
1940 # define task_thread_info(task)	(&(task)->thread_info)
1941 #else
1942 # define task_thread_info(task)	((struct thread_info *)(task)->stack)
1943 #endif
1944 
1945 /*
1946  * find a task by one of its numerical ids
1947  *
1948  * find_task_by_pid_ns():
1949  *      finds a task by its pid in the specified namespace
1950  * find_task_by_vpid():
1951  *      finds a task by its virtual pid
1952  *
1953  * see also find_vpid() etc in include/linux/pid.h
1954  */
1955 
1956 extern struct task_struct *find_task_by_vpid(pid_t nr);
1957 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns);
1958 
1959 /*
1960  * find a task by its virtual pid and get the task struct
1961  */
1962 extern struct task_struct *find_get_task_by_vpid(pid_t nr);
1963 
1964 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
1965 extern int wake_up_process(struct task_struct *tsk);
1966 extern void wake_up_new_task(struct task_struct *tsk);
1967 
1968 extern void kick_process(struct task_struct *tsk);
1969 
1970 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
1971 #define set_task_comm(tsk, from) ({			\
1972 	BUILD_BUG_ON(sizeof(from) != TASK_COMM_LEN);	\
1973 	__set_task_comm(tsk, from, false);		\
1974 })
1975 
1976 /*
1977  * - Why not use task_lock()?
1978  *   User space can randomly change their names anyway, so locking for readers
1979  *   doesn't make sense. For writers, locking is probably necessary, as a race
1980  *   condition could lead to long-term mixed results.
1981  *   The strscpy_pad() in __set_task_comm() can ensure that the task comm is
1982  *   always NUL-terminated and zero-padded. Therefore the race condition between
1983  *   reader and writer is not an issue.
1984  *
1985  * - BUILD_BUG_ON() can help prevent the buf from being truncated.
1986  *   Since the callers don't perform any return value checks, this safeguard is
1987  *   necessary.
1988  */
1989 #define get_task_comm(buf, tsk) ({			\
1990 	BUILD_BUG_ON(sizeof(buf) < TASK_COMM_LEN);	\
1991 	strscpy_pad(buf, (tsk)->comm);			\
1992 	buf;						\
1993 })
1994 
scheduler_ipi(void)1995 static __always_inline void scheduler_ipi(void)
1996 {
1997 	/*
1998 	 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting
1999 	 * TIF_NEED_RESCHED remotely (for the first time) will also send
2000 	 * this IPI.
2001 	 */
2002 	preempt_fold_need_resched();
2003 }
2004 
2005 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state);
2006 
2007 /*
2008  * Set thread flags in other task's structures.
2009  * See asm/thread_info.h for TIF_xxxx flags available:
2010  */
set_tsk_thread_flag(struct task_struct * tsk,int flag)2011 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2012 {
2013 	set_ti_thread_flag(task_thread_info(tsk), flag);
2014 }
2015 
clear_tsk_thread_flag(struct task_struct * tsk,int flag)2016 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2017 {
2018 	clear_ti_thread_flag(task_thread_info(tsk), flag);
2019 }
2020 
update_tsk_thread_flag(struct task_struct * tsk,int flag,bool value)2021 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag,
2022 					  bool value)
2023 {
2024 	update_ti_thread_flag(task_thread_info(tsk), flag, value);
2025 }
2026 
test_and_set_tsk_thread_flag(struct task_struct * tsk,int flag)2027 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2028 {
2029 	return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2030 }
2031 
test_and_clear_tsk_thread_flag(struct task_struct * tsk,int flag)2032 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2033 {
2034 	return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2035 }
2036 
test_tsk_thread_flag(struct task_struct * tsk,int flag)2037 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2038 {
2039 	return test_ti_thread_flag(task_thread_info(tsk), flag);
2040 }
2041 
set_tsk_need_resched(struct task_struct * tsk)2042 static inline void set_tsk_need_resched(struct task_struct *tsk)
2043 {
2044 	if (tracepoint_enabled(sched_set_need_resched_tp) &&
2045 	    !test_tsk_thread_flag(tsk, TIF_NEED_RESCHED))
2046 		__trace_set_need_resched(tsk, TIF_NEED_RESCHED);
2047 	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2048 }
2049 
clear_tsk_need_resched(struct task_struct * tsk)2050 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2051 {
2052 	atomic_long_andnot(_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY,
2053 			   (atomic_long_t *)&task_thread_info(tsk)->flags);
2054 }
2055 
test_tsk_need_resched(struct task_struct * tsk)2056 static inline int test_tsk_need_resched(struct task_struct *tsk)
2057 {
2058 	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2059 }
2060 
2061 /*
2062  * cond_resched() and cond_resched_lock(): latency reduction via
2063  * explicit rescheduling in places that are safe. The return
2064  * value indicates whether a reschedule was done in fact.
2065  * cond_resched_lock() will drop the spinlock before scheduling,
2066  */
2067 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC)
2068 extern int __cond_resched(void);
2069 
2070 #if defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL)
2071 
2072 DECLARE_STATIC_CALL(cond_resched, __cond_resched);
2073 
_cond_resched(void)2074 static __always_inline int _cond_resched(void)
2075 {
2076 	return static_call_mod(cond_resched)();
2077 }
2078 
2079 #elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY)
2080 
2081 extern int dynamic_cond_resched(void);
2082 
_cond_resched(void)2083 static __always_inline int _cond_resched(void)
2084 {
2085 	return dynamic_cond_resched();
2086 }
2087 
2088 #else /* !CONFIG_PREEMPTION */
2089 
_cond_resched(void)2090 static inline int _cond_resched(void)
2091 {
2092 	return __cond_resched();
2093 }
2094 
2095 #endif /* PREEMPT_DYNAMIC && CONFIG_HAVE_PREEMPT_DYNAMIC_CALL */
2096 
2097 #else /* CONFIG_PREEMPTION && !CONFIG_PREEMPT_DYNAMIC */
2098 
_cond_resched(void)2099 static inline int _cond_resched(void)
2100 {
2101 	return 0;
2102 }
2103 
2104 #endif /* !CONFIG_PREEMPTION || CONFIG_PREEMPT_DYNAMIC */
2105 
2106 #define cond_resched() ({			\
2107 	__might_resched(__FILE__, __LINE__, 0);	\
2108 	_cond_resched();			\
2109 })
2110 
2111 extern int __cond_resched_lock(spinlock_t *lock);
2112 extern int __cond_resched_rwlock_read(rwlock_t *lock);
2113 extern int __cond_resched_rwlock_write(rwlock_t *lock);
2114 
2115 #define MIGHT_RESCHED_RCU_SHIFT		8
2116 #define MIGHT_RESCHED_PREEMPT_MASK	((1U << MIGHT_RESCHED_RCU_SHIFT) - 1)
2117 
2118 #ifndef CONFIG_PREEMPT_RT
2119 /*
2120  * Non RT kernels have an elevated preempt count due to the held lock,
2121  * but are not allowed to be inside a RCU read side critical section
2122  */
2123 # define PREEMPT_LOCK_RESCHED_OFFSETS	PREEMPT_LOCK_OFFSET
2124 #else
2125 /*
2126  * spin/rw_lock() on RT implies rcu_read_lock(). The might_sleep() check in
2127  * cond_resched*lock() has to take that into account because it checks for
2128  * preempt_count() and rcu_preempt_depth().
2129  */
2130 # define PREEMPT_LOCK_RESCHED_OFFSETS	\
2131 	(PREEMPT_LOCK_OFFSET + (1U << MIGHT_RESCHED_RCU_SHIFT))
2132 #endif
2133 
2134 #define cond_resched_lock(lock) ({						\
2135 	__might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS);	\
2136 	__cond_resched_lock(lock);						\
2137 })
2138 
2139 #define cond_resched_rwlock_read(lock) ({					\
2140 	__might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS);	\
2141 	__cond_resched_rwlock_read(lock);					\
2142 })
2143 
2144 #define cond_resched_rwlock_write(lock) ({					\
2145 	__might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS);	\
2146 	__cond_resched_rwlock_write(lock);					\
2147 })
2148 
2149 #ifndef CONFIG_PREEMPT_RT
__get_task_blocked_on(struct task_struct * p)2150 static inline struct mutex *__get_task_blocked_on(struct task_struct *p)
2151 {
2152 	struct mutex *m = p->blocked_on;
2153 
2154 	if (m)
2155 		lockdep_assert_held_once(&m->wait_lock);
2156 	return m;
2157 }
2158 
__set_task_blocked_on(struct task_struct * p,struct mutex * m)2159 static inline void __set_task_blocked_on(struct task_struct *p, struct mutex *m)
2160 {
2161 	struct mutex *blocked_on = READ_ONCE(p->blocked_on);
2162 
2163 	WARN_ON_ONCE(!m);
2164 	/* The task should only be setting itself as blocked */
2165 	WARN_ON_ONCE(p != current);
2166 	/* Currently we serialize blocked_on under the mutex::wait_lock */
2167 	lockdep_assert_held_once(&m->wait_lock);
2168 	/*
2169 	 * Check ensure we don't overwrite existing mutex value
2170 	 * with a different mutex. Note, setting it to the same
2171 	 * lock repeatedly is ok.
2172 	 */
2173 	WARN_ON_ONCE(blocked_on && blocked_on != m);
2174 	WRITE_ONCE(p->blocked_on, m);
2175 }
2176 
set_task_blocked_on(struct task_struct * p,struct mutex * m)2177 static inline void set_task_blocked_on(struct task_struct *p, struct mutex *m)
2178 {
2179 	guard(raw_spinlock_irqsave)(&m->wait_lock);
2180 	__set_task_blocked_on(p, m);
2181 }
2182 
__clear_task_blocked_on(struct task_struct * p,struct mutex * m)2183 static inline void __clear_task_blocked_on(struct task_struct *p, struct mutex *m)
2184 {
2185 	if (m) {
2186 		struct mutex *blocked_on = READ_ONCE(p->blocked_on);
2187 
2188 		/* Currently we serialize blocked_on under the mutex::wait_lock */
2189 		lockdep_assert_held_once(&m->wait_lock);
2190 		/*
2191 		 * There may be cases where we re-clear already cleared
2192 		 * blocked_on relationships, but make sure we are not
2193 		 * clearing the relationship with a different lock.
2194 		 */
2195 		WARN_ON_ONCE(blocked_on && blocked_on != m);
2196 	}
2197 	WRITE_ONCE(p->blocked_on, NULL);
2198 }
2199 
clear_task_blocked_on(struct task_struct * p,struct mutex * m)2200 static inline void clear_task_blocked_on(struct task_struct *p, struct mutex *m)
2201 {
2202 	guard(raw_spinlock_irqsave)(&m->wait_lock);
2203 	__clear_task_blocked_on(p, m);
2204 }
2205 #else
__clear_task_blocked_on(struct task_struct * p,struct rt_mutex * m)2206 static inline void __clear_task_blocked_on(struct task_struct *p, struct rt_mutex *m)
2207 {
2208 }
2209 
clear_task_blocked_on(struct task_struct * p,struct rt_mutex * m)2210 static inline void clear_task_blocked_on(struct task_struct *p, struct rt_mutex *m)
2211 {
2212 }
2213 #endif /* !CONFIG_PREEMPT_RT */
2214 
need_resched(void)2215 static __always_inline bool need_resched(void)
2216 {
2217 	return unlikely(tif_need_resched());
2218 }
2219 
2220 /*
2221  * Wrappers for p->thread_info->cpu access. No-op on UP.
2222  */
2223 #ifdef CONFIG_SMP
2224 
task_cpu(const struct task_struct * p)2225 static inline unsigned int task_cpu(const struct task_struct *p)
2226 {
2227 	return READ_ONCE(task_thread_info(p)->cpu);
2228 }
2229 
2230 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2231 
2232 #else
2233 
task_cpu(const struct task_struct * p)2234 static inline unsigned int task_cpu(const struct task_struct *p)
2235 {
2236 	return 0;
2237 }
2238 
set_task_cpu(struct task_struct * p,unsigned int cpu)2239 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2240 {
2241 }
2242 
2243 #endif /* CONFIG_SMP */
2244 
task_is_runnable(struct task_struct * p)2245 static inline bool task_is_runnable(struct task_struct *p)
2246 {
2247 	return p->on_rq && !p->se.sched_delayed;
2248 }
2249 
2250 extern bool sched_task_on_rq(struct task_struct *p);
2251 extern unsigned long get_wchan(struct task_struct *p);
2252 extern struct task_struct *cpu_curr_snapshot(int cpu);
2253 
2254 /*
2255  * In order to reduce various lock holder preemption latencies provide an
2256  * interface to see if a vCPU is currently running or not.
2257  *
2258  * This allows us to terminate optimistic spin loops and block, analogous to
2259  * the native optimistic spin heuristic of testing if the lock owner task is
2260  * running or not.
2261  */
2262 #ifndef vcpu_is_preempted
vcpu_is_preempted(int cpu)2263 static inline bool vcpu_is_preempted(int cpu)
2264 {
2265 	return false;
2266 }
2267 #endif
2268 
2269 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2270 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2271 
2272 #ifndef TASK_SIZE_OF
2273 #define TASK_SIZE_OF(tsk)	TASK_SIZE
2274 #endif
2275 
owner_on_cpu(struct task_struct * owner)2276 static inline bool owner_on_cpu(struct task_struct *owner)
2277 {
2278 	/*
2279 	 * As lock holder preemption issue, we both skip spinning if
2280 	 * task is not on cpu or its cpu is preempted
2281 	 */
2282 	return READ_ONCE(owner->on_cpu) && !vcpu_is_preempted(task_cpu(owner));
2283 }
2284 
2285 /* Returns effective CPU energy utilization, as seen by the scheduler */
2286 unsigned long sched_cpu_util(int cpu);
2287 
2288 #ifdef CONFIG_SCHED_CORE
2289 extern void sched_core_free(struct task_struct *tsk);
2290 extern void sched_core_fork(struct task_struct *p);
2291 extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type,
2292 				unsigned long uaddr);
2293 extern int sched_core_idle_cpu(int cpu);
2294 #else
sched_core_free(struct task_struct * tsk)2295 static inline void sched_core_free(struct task_struct *tsk) { }
sched_core_fork(struct task_struct * p)2296 static inline void sched_core_fork(struct task_struct *p) { }
sched_core_idle_cpu(int cpu)2297 static inline int sched_core_idle_cpu(int cpu) { return idle_cpu(cpu); }
2298 #endif
2299 
2300 extern void sched_set_stop_task(int cpu, struct task_struct *stop);
2301 
2302 #ifdef CONFIG_MEM_ALLOC_PROFILING
alloc_tag_save(struct alloc_tag * tag)2303 static __always_inline struct alloc_tag *alloc_tag_save(struct alloc_tag *tag)
2304 {
2305 	swap(current->alloc_tag, tag);
2306 	return tag;
2307 }
2308 
alloc_tag_restore(struct alloc_tag * tag,struct alloc_tag * old)2309 static __always_inline void alloc_tag_restore(struct alloc_tag *tag, struct alloc_tag *old)
2310 {
2311 #ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG
2312 	WARN(current->alloc_tag != tag, "current->alloc_tag was changed:\n");
2313 #endif
2314 	current->alloc_tag = old;
2315 }
2316 #else
2317 #define alloc_tag_save(_tag)			NULL
2318 #define alloc_tag_restore(_tag, _old)		do {} while (0)
2319 #endif
2320 
2321 #ifndef MODULE
2322 #ifndef COMPILE_OFFSETS
2323 
2324 extern void ___migrate_enable(void);
2325 
2326 struct rq;
2327 DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
2328 
2329 /*
2330  * The "struct rq" is not available here, so we can't access the
2331  * "runqueues" with this_cpu_ptr(), as the compilation will fail in
2332  * this_cpu_ptr() -> raw_cpu_ptr() -> __verify_pcpu_ptr():
2333  *   typeof((ptr) + 0)
2334  *
2335  * So use arch_raw_cpu_ptr()/PERCPU_PTR() directly here.
2336  */
2337 #ifdef CONFIG_SMP
2338 #define this_rq_raw() arch_raw_cpu_ptr(&runqueues)
2339 #else
2340 #define this_rq_raw() PERCPU_PTR(&runqueues)
2341 #endif
2342 #define this_rq_pinned() (*(unsigned int *)((void *)this_rq_raw() + RQ_nr_pinned))
2343 
__migrate_enable(void)2344 static inline void __migrate_enable(void)
2345 {
2346 	struct task_struct *p = current;
2347 
2348 #ifdef CONFIG_DEBUG_PREEMPT
2349 	/*
2350 	 * Check both overflow from migrate_disable() and superfluous
2351 	 * migrate_enable().
2352 	 */
2353 	if (WARN_ON_ONCE((s16)p->migration_disabled <= 0))
2354 		return;
2355 #endif
2356 
2357 	if (p->migration_disabled > 1) {
2358 		p->migration_disabled--;
2359 		return;
2360 	}
2361 
2362 	/*
2363 	 * Ensure stop_task runs either before or after this, and that
2364 	 * __set_cpus_allowed_ptr(SCA_MIGRATE_ENABLE) doesn't schedule().
2365 	 */
2366 	guard(preempt)();
2367 	if (unlikely(p->cpus_ptr != &p->cpus_mask))
2368 		___migrate_enable();
2369 	/*
2370 	 * Mustn't clear migration_disabled() until cpus_ptr points back at the
2371 	 * regular cpus_mask, otherwise things that race (eg.
2372 	 * select_fallback_rq) get confused.
2373 	 */
2374 	barrier();
2375 	p->migration_disabled = 0;
2376 	this_rq_pinned()--;
2377 }
2378 
__migrate_disable(void)2379 static inline void __migrate_disable(void)
2380 {
2381 	struct task_struct *p = current;
2382 
2383 	if (p->migration_disabled) {
2384 #ifdef CONFIG_DEBUG_PREEMPT
2385 		/*
2386 		 *Warn about overflow half-way through the range.
2387 		 */
2388 		WARN_ON_ONCE((s16)p->migration_disabled < 0);
2389 #endif
2390 		p->migration_disabled++;
2391 		return;
2392 	}
2393 
2394 	guard(preempt)();
2395 	this_rq_pinned()++;
2396 	p->migration_disabled = 1;
2397 }
2398 #else /* !COMPILE_OFFSETS */
__migrate_disable(void)2399 static inline void __migrate_disable(void) { }
__migrate_enable(void)2400 static inline void __migrate_enable(void) { }
2401 #endif /* !COMPILE_OFFSETS */
2402 
2403 /*
2404  * So that it is possible to not export the runqueues variable, define and
2405  * export migrate_enable/migrate_disable in kernel/sched/core.c too, and use
2406  * them for the modules. The macro "INSTANTIATE_EXPORTED_MIGRATE_DISABLE" will
2407  * be defined in kernel/sched/core.c.
2408  */
2409 #ifndef INSTANTIATE_EXPORTED_MIGRATE_DISABLE
migrate_disable(void)2410 static inline void migrate_disable(void)
2411 {
2412 	__migrate_disable();
2413 }
2414 
migrate_enable(void)2415 static inline void migrate_enable(void)
2416 {
2417 	__migrate_enable();
2418 }
2419 #else /* INSTANTIATE_EXPORTED_MIGRATE_DISABLE */
2420 extern void migrate_disable(void);
2421 extern void migrate_enable(void);
2422 #endif /* INSTANTIATE_EXPORTED_MIGRATE_DISABLE */
2423 
2424 #else /* MODULE */
2425 extern void migrate_disable(void);
2426 extern void migrate_enable(void);
2427 #endif /* MODULE */
2428 
2429 DEFINE_LOCK_GUARD_0(migrate, migrate_disable(), migrate_enable())
2430 
2431 #endif
2432