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.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/syscall_user_dispatch_types.h>
38 #include <linux/mm_types_task.h>
39 #include <linux/task_io_accounting.h>
40 #include <linux/posix-timers_types.h>
41 #include <linux/restart_block.h>
42 #include <uapi/linux/rseq.h>
43 #include <linux/seqlock_types.h>
44 #include <linux/kcsan.h>
45 #include <linux/rv.h>
46 #include <linux/livepatch_sched.h>
47 #include <linux/uidgid_types.h>
48 #include <asm/kmap_size.h>
49
50 /* task_struct member predeclarations (sorted alphabetically): */
51 struct audit_context;
52 struct bio_list;
53 struct blk_plug;
54 struct bpf_local_storage;
55 struct bpf_run_ctx;
56 struct capture_control;
57 struct cfs_rq;
58 struct fs_struct;
59 struct futex_pi_state;
60 struct io_context;
61 struct io_uring_task;
62 struct mempolicy;
63 struct nameidata;
64 struct nsproxy;
65 struct perf_event_context;
66 struct pid_namespace;
67 struct pipe_inode_info;
68 struct rcu_node;
69 struct reclaim_state;
70 struct robust_list_head;
71 struct root_domain;
72 struct rq;
73 struct sched_attr;
74 struct sched_dl_entity;
75 struct seq_file;
76 struct sighand_struct;
77 struct signal_struct;
78 struct task_delay_info;
79 struct task_group;
80 struct task_struct;
81 struct user_event_mm;
82
83 /*
84 * Task state bitmask. NOTE! These bits are also
85 * encoded in fs/proc/array.c: get_task_state().
86 *
87 * We have two separate sets of flags: task->__state
88 * is about runnability, while task->exit_state are
89 * about the task exiting. Confusing, but this way
90 * modifying one set can't modify the other one by
91 * mistake.
92 */
93
94 /* Used in tsk->__state: */
95 #define TASK_RUNNING 0x00000000
96 #define TASK_INTERRUPTIBLE 0x00000001
97 #define TASK_UNINTERRUPTIBLE 0x00000002
98 #define __TASK_STOPPED 0x00000004
99 #define __TASK_TRACED 0x00000008
100 /* Used in tsk->exit_state: */
101 #define EXIT_DEAD 0x00000010
102 #define EXIT_ZOMBIE 0x00000020
103 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD)
104 /* Used in tsk->__state again: */
105 #define TASK_PARKED 0x00000040
106 #define TASK_DEAD 0x00000080
107 #define TASK_WAKEKILL 0x00000100
108 #define TASK_WAKING 0x00000200
109 #define TASK_NOLOAD 0x00000400
110 #define TASK_NEW 0x00000800
111 #define TASK_RTLOCK_WAIT 0x00001000
112 #define TASK_FREEZABLE 0x00002000
113 #define __TASK_FREEZABLE_UNSAFE (0x00004000 * IS_ENABLED(CONFIG_LOCKDEP))
114 #define TASK_FROZEN 0x00008000
115 #define TASK_STATE_MAX 0x00010000
116
117 #define TASK_ANY (TASK_STATE_MAX-1)
118
119 /*
120 * DO NOT ADD ANY NEW USERS !
121 */
122 #define TASK_FREEZABLE_UNSAFE (TASK_FREEZABLE | __TASK_FREEZABLE_UNSAFE)
123
124 /* Convenience macros for the sake of set_current_state: */
125 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
126 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED)
127 #define TASK_TRACED __TASK_TRACED
128
129 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
130
131 /* Convenience macros for the sake of wake_up(): */
132 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
133
134 /* get_task_state(): */
135 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \
136 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
137 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
138 TASK_PARKED)
139
140 #define task_is_running(task) (READ_ONCE((task)->__state) == TASK_RUNNING)
141
142 #define task_is_traced(task) ((READ_ONCE(task->jobctl) & JOBCTL_TRACED) != 0)
143 #define task_is_stopped(task) ((READ_ONCE(task->jobctl) & JOBCTL_STOPPED) != 0)
144 #define task_is_stopped_or_traced(task) ((READ_ONCE(task->jobctl) & (JOBCTL_STOPPED | JOBCTL_TRACED)) != 0)
145
146 /*
147 * Special states are those that do not use the normal wait-loop pattern. See
148 * the comment with set_special_state().
149 */
150 #define is_special_task_state(state) \
151 ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD))
152
153 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
154 # define debug_normal_state_change(state_value) \
155 do { \
156 WARN_ON_ONCE(is_special_task_state(state_value)); \
157 current->task_state_change = _THIS_IP_; \
158 } while (0)
159
160 # define debug_special_state_change(state_value) \
161 do { \
162 WARN_ON_ONCE(!is_special_task_state(state_value)); \
163 current->task_state_change = _THIS_IP_; \
164 } while (0)
165
166 # define debug_rtlock_wait_set_state() \
167 do { \
168 current->saved_state_change = current->task_state_change;\
169 current->task_state_change = _THIS_IP_; \
170 } while (0)
171
172 # define debug_rtlock_wait_restore_state() \
173 do { \
174 current->task_state_change = current->saved_state_change;\
175 } while (0)
176
177 #else
178 # define debug_normal_state_change(cond) do { } while (0)
179 # define debug_special_state_change(cond) do { } while (0)
180 # define debug_rtlock_wait_set_state() do { } while (0)
181 # define debug_rtlock_wait_restore_state() do { } while (0)
182 #endif
183
184 /*
185 * set_current_state() includes a barrier so that the write of current->__state
186 * is correctly serialised wrt the caller's subsequent test of whether to
187 * actually sleep:
188 *
189 * for (;;) {
190 * set_current_state(TASK_UNINTERRUPTIBLE);
191 * if (CONDITION)
192 * break;
193 *
194 * schedule();
195 * }
196 * __set_current_state(TASK_RUNNING);
197 *
198 * If the caller does not need such serialisation (because, for instance, the
199 * CONDITION test and condition change and wakeup are under the same lock) then
200 * use __set_current_state().
201 *
202 * The above is typically ordered against the wakeup, which does:
203 *
204 * CONDITION = 1;
205 * wake_up_state(p, TASK_UNINTERRUPTIBLE);
206 *
207 * where wake_up_state()/try_to_wake_up() executes a full memory barrier before
208 * accessing p->__state.
209 *
210 * Wakeup will do: if (@state & p->__state) p->__state = TASK_RUNNING, that is,
211 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
212 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
213 *
214 * However, with slightly different timing the wakeup TASK_RUNNING store can
215 * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not
216 * a problem either because that will result in one extra go around the loop
217 * and our @cond test will save the day.
218 *
219 * Also see the comments of try_to_wake_up().
220 */
221 #define __set_current_state(state_value) \
222 do { \
223 debug_normal_state_change((state_value)); \
224 WRITE_ONCE(current->__state, (state_value)); \
225 } while (0)
226
227 #define set_current_state(state_value) \
228 do { \
229 debug_normal_state_change((state_value)); \
230 smp_store_mb(current->__state, (state_value)); \
231 } while (0)
232
233 /*
234 * set_special_state() should be used for those states when the blocking task
235 * can not use the regular condition based wait-loop. In that case we must
236 * serialize against wakeups such that any possible in-flight TASK_RUNNING
237 * stores will not collide with our state change.
238 */
239 #define set_special_state(state_value) \
240 do { \
241 unsigned long flags; /* may shadow */ \
242 \
243 raw_spin_lock_irqsave(¤t->pi_lock, flags); \
244 debug_special_state_change((state_value)); \
245 WRITE_ONCE(current->__state, (state_value)); \
246 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \
247 } while (0)
248
249 /*
250 * PREEMPT_RT specific variants for "sleeping" spin/rwlocks
251 *
252 * RT's spin/rwlock substitutions are state preserving. The state of the
253 * task when blocking on the lock is saved in task_struct::saved_state and
254 * restored after the lock has been acquired. These operations are
255 * serialized by task_struct::pi_lock against try_to_wake_up(). Any non RT
256 * lock related wakeups while the task is blocked on the lock are
257 * redirected to operate on task_struct::saved_state to ensure that these
258 * are not dropped. On restore task_struct::saved_state is set to
259 * TASK_RUNNING so any wakeup attempt redirected to saved_state will fail.
260 *
261 * The lock operation looks like this:
262 *
263 * current_save_and_set_rtlock_wait_state();
264 * for (;;) {
265 * if (try_lock())
266 * break;
267 * raw_spin_unlock_irq(&lock->wait_lock);
268 * schedule_rtlock();
269 * raw_spin_lock_irq(&lock->wait_lock);
270 * set_current_state(TASK_RTLOCK_WAIT);
271 * }
272 * current_restore_rtlock_saved_state();
273 */
274 #define current_save_and_set_rtlock_wait_state() \
275 do { \
276 lockdep_assert_irqs_disabled(); \
277 raw_spin_lock(¤t->pi_lock); \
278 current->saved_state = current->__state; \
279 debug_rtlock_wait_set_state(); \
280 WRITE_ONCE(current->__state, TASK_RTLOCK_WAIT); \
281 raw_spin_unlock(¤t->pi_lock); \
282 } while (0);
283
284 #define current_restore_rtlock_saved_state() \
285 do { \
286 lockdep_assert_irqs_disabled(); \
287 raw_spin_lock(¤t->pi_lock); \
288 debug_rtlock_wait_restore_state(); \
289 WRITE_ONCE(current->__state, current->saved_state); \
290 current->saved_state = TASK_RUNNING; \
291 raw_spin_unlock(¤t->pi_lock); \
292 } while (0);
293
294 #define get_current_state() READ_ONCE(current->__state)
295
296 /*
297 * Define the task command name length as enum, then it can be visible to
298 * BPF programs.
299 */
300 enum {
301 TASK_COMM_LEN = 16,
302 };
303
304 extern void scheduler_tick(void);
305
306 #define MAX_SCHEDULE_TIMEOUT LONG_MAX
307
308 extern long schedule_timeout(long timeout);
309 extern long schedule_timeout_interruptible(long timeout);
310 extern long schedule_timeout_killable(long timeout);
311 extern long schedule_timeout_uninterruptible(long timeout);
312 extern long schedule_timeout_idle(long timeout);
313 asmlinkage void schedule(void);
314 extern void schedule_preempt_disabled(void);
315 asmlinkage void preempt_schedule_irq(void);
316 #ifdef CONFIG_PREEMPT_RT
317 extern void schedule_rtlock(void);
318 #endif
319
320 extern int __must_check io_schedule_prepare(void);
321 extern void io_schedule_finish(int token);
322 extern long io_schedule_timeout(long timeout);
323 extern void io_schedule(void);
324
325 /**
326 * struct prev_cputime - snapshot of system and user cputime
327 * @utime: time spent in user mode
328 * @stime: time spent in system mode
329 * @lock: protects the above two fields
330 *
331 * Stores previous user/system time values such that we can guarantee
332 * monotonicity.
333 */
334 struct prev_cputime {
335 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
336 u64 utime;
337 u64 stime;
338 raw_spinlock_t lock;
339 #endif
340 };
341
342 enum vtime_state {
343 /* Task is sleeping or running in a CPU with VTIME inactive: */
344 VTIME_INACTIVE = 0,
345 /* Task is idle */
346 VTIME_IDLE,
347 /* Task runs in kernelspace in a CPU with VTIME active: */
348 VTIME_SYS,
349 /* Task runs in userspace in a CPU with VTIME active: */
350 VTIME_USER,
351 /* Task runs as guests in a CPU with VTIME active: */
352 VTIME_GUEST,
353 };
354
355 struct vtime {
356 seqcount_t seqcount;
357 unsigned long long starttime;
358 enum vtime_state state;
359 unsigned int cpu;
360 u64 utime;
361 u64 stime;
362 u64 gtime;
363 };
364
365 /*
366 * Utilization clamp constraints.
367 * @UCLAMP_MIN: Minimum utilization
368 * @UCLAMP_MAX: Maximum utilization
369 * @UCLAMP_CNT: Utilization clamp constraints count
370 */
371 enum uclamp_id {
372 UCLAMP_MIN = 0,
373 UCLAMP_MAX,
374 UCLAMP_CNT
375 };
376
377 #ifdef CONFIG_SMP
378 extern struct root_domain def_root_domain;
379 extern struct mutex sched_domains_mutex;
380 #endif
381
382 struct sched_param {
383 int sched_priority;
384 };
385
386 struct sched_info {
387 #ifdef CONFIG_SCHED_INFO
388 /* Cumulative counters: */
389
390 /* # of times we have run on this CPU: */
391 unsigned long pcount;
392
393 /* Time spent waiting on a runqueue: */
394 unsigned long long run_delay;
395
396 /* Timestamps: */
397
398 /* When did we last run on a CPU? */
399 unsigned long long last_arrival;
400
401 /* When were we last queued to run? */
402 unsigned long long last_queued;
403
404 #endif /* CONFIG_SCHED_INFO */
405 };
406
407 /*
408 * Integer metrics need fixed point arithmetic, e.g., sched/fair
409 * has a few: load, load_avg, util_avg, freq, and capacity.
410 *
411 * We define a basic fixed point arithmetic range, and then formalize
412 * all these metrics based on that basic range.
413 */
414 # define SCHED_FIXEDPOINT_SHIFT 10
415 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT)
416
417 /* Increase resolution of cpu_capacity calculations */
418 # define SCHED_CAPACITY_SHIFT SCHED_FIXEDPOINT_SHIFT
419 # define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT)
420
421 struct load_weight {
422 unsigned long weight;
423 u32 inv_weight;
424 };
425
426 /*
427 * The load/runnable/util_avg accumulates an infinite geometric series
428 * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c).
429 *
430 * [load_avg definition]
431 *
432 * load_avg = runnable% * scale_load_down(load)
433 *
434 * [runnable_avg definition]
435 *
436 * runnable_avg = runnable% * SCHED_CAPACITY_SCALE
437 *
438 * [util_avg definition]
439 *
440 * util_avg = running% * SCHED_CAPACITY_SCALE
441 *
442 * where runnable% is the time ratio that a sched_entity is runnable and
443 * running% the time ratio that a sched_entity is running.
444 *
445 * For cfs_rq, they are the aggregated values of all runnable and blocked
446 * sched_entities.
447 *
448 * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU
449 * capacity scaling. The scaling is done through the rq_clock_pelt that is used
450 * for computing those signals (see update_rq_clock_pelt())
451 *
452 * N.B., the above ratios (runnable% and running%) themselves are in the
453 * range of [0, 1]. To do fixed point arithmetics, we therefore scale them
454 * to as large a range as necessary. This is for example reflected by
455 * util_avg's SCHED_CAPACITY_SCALE.
456 *
457 * [Overflow issue]
458 *
459 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
460 * with the highest load (=88761), always runnable on a single cfs_rq,
461 * and should not overflow as the number already hits PID_MAX_LIMIT.
462 *
463 * For all other cases (including 32-bit kernels), struct load_weight's
464 * weight will overflow first before we do, because:
465 *
466 * Max(load_avg) <= Max(load.weight)
467 *
468 * Then it is the load_weight's responsibility to consider overflow
469 * issues.
470 */
471 struct sched_avg {
472 u64 last_update_time;
473 u64 load_sum;
474 u64 runnable_sum;
475 u32 util_sum;
476 u32 period_contrib;
477 unsigned long load_avg;
478 unsigned long runnable_avg;
479 unsigned long util_avg;
480 unsigned int util_est;
481 } ____cacheline_aligned;
482
483 /*
484 * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg
485 * updates. When a task is dequeued, its util_est should not be updated if its
486 * util_avg has not been updated in the meantime.
487 * This information is mapped into the MSB bit of util_est at dequeue time.
488 * Since max value of util_est for a task is 1024 (PELT util_avg for a task)
489 * it is safe to use MSB.
490 */
491 #define UTIL_EST_WEIGHT_SHIFT 2
492 #define UTIL_AVG_UNCHANGED 0x80000000
493
494 struct sched_statistics {
495 #ifdef CONFIG_SCHEDSTATS
496 u64 wait_start;
497 u64 wait_max;
498 u64 wait_count;
499 u64 wait_sum;
500 u64 iowait_count;
501 u64 iowait_sum;
502
503 u64 sleep_start;
504 u64 sleep_max;
505 s64 sum_sleep_runtime;
506
507 u64 block_start;
508 u64 block_max;
509 s64 sum_block_runtime;
510
511 s64 exec_max;
512 u64 slice_max;
513
514 u64 nr_migrations_cold;
515 u64 nr_failed_migrations_affine;
516 u64 nr_failed_migrations_running;
517 u64 nr_failed_migrations_hot;
518 u64 nr_forced_migrations;
519
520 u64 nr_wakeups;
521 u64 nr_wakeups_sync;
522 u64 nr_wakeups_migrate;
523 u64 nr_wakeups_local;
524 u64 nr_wakeups_remote;
525 u64 nr_wakeups_affine;
526 u64 nr_wakeups_affine_attempts;
527 u64 nr_wakeups_passive;
528 u64 nr_wakeups_idle;
529
530 #ifdef CONFIG_SCHED_CORE
531 u64 core_forceidle_sum;
532 #endif
533 #endif /* CONFIG_SCHEDSTATS */
534 } ____cacheline_aligned;
535
536 struct sched_entity {
537 /* For load-balancing: */
538 struct load_weight load;
539 struct rb_node run_node;
540 u64 deadline;
541 u64 min_vruntime;
542
543 struct list_head group_node;
544 unsigned int on_rq;
545
546 u64 exec_start;
547 u64 sum_exec_runtime;
548 u64 prev_sum_exec_runtime;
549 u64 vruntime;
550 s64 vlag;
551 u64 slice;
552
553 u64 nr_migrations;
554
555 #ifdef CONFIG_FAIR_GROUP_SCHED
556 int depth;
557 struct sched_entity *parent;
558 /* rq on which this entity is (to be) queued: */
559 struct cfs_rq *cfs_rq;
560 /* rq "owned" by this entity/group: */
561 struct cfs_rq *my_q;
562 /* cached value of my_q->h_nr_running */
563 unsigned long runnable_weight;
564 #endif
565
566 #ifdef CONFIG_SMP
567 /*
568 * Per entity load average tracking.
569 *
570 * Put into separate cache line so it does not
571 * collide with read-mostly values above.
572 */
573 struct sched_avg avg;
574 #endif
575 };
576
577 struct sched_rt_entity {
578 struct list_head run_list;
579 unsigned long timeout;
580 unsigned long watchdog_stamp;
581 unsigned int time_slice;
582 unsigned short on_rq;
583 unsigned short on_list;
584
585 struct sched_rt_entity *back;
586 #ifdef CONFIG_RT_GROUP_SCHED
587 struct sched_rt_entity *parent;
588 /* rq on which this entity is (to be) queued: */
589 struct rt_rq *rt_rq;
590 /* rq "owned" by this entity/group: */
591 struct rt_rq *my_q;
592 #endif
593 } __randomize_layout;
594
595 typedef bool (*dl_server_has_tasks_f)(struct sched_dl_entity *);
596 typedef struct task_struct *(*dl_server_pick_f)(struct sched_dl_entity *);
597
598 struct sched_dl_entity {
599 struct rb_node rb_node;
600
601 /*
602 * Original scheduling parameters. Copied here from sched_attr
603 * during sched_setattr(), they will remain the same until
604 * the next sched_setattr().
605 */
606 u64 dl_runtime; /* Maximum runtime for each instance */
607 u64 dl_deadline; /* Relative deadline of each instance */
608 u64 dl_period; /* Separation of two instances (period) */
609 u64 dl_bw; /* dl_runtime / dl_period */
610 u64 dl_density; /* dl_runtime / dl_deadline */
611
612 /*
613 * Actual scheduling parameters. Initialized with the values above,
614 * they are continuously updated during task execution. Note that
615 * the remaining runtime could be < 0 in case we are in overrun.
616 */
617 s64 runtime; /* Remaining runtime for this instance */
618 u64 deadline; /* Absolute deadline for this instance */
619 unsigned int flags; /* Specifying the scheduler behaviour */
620
621 /*
622 * Some bool flags:
623 *
624 * @dl_throttled tells if we exhausted the runtime. If so, the
625 * task has to wait for a replenishment to be performed at the
626 * next firing of dl_timer.
627 *
628 * @dl_yielded tells if task gave up the CPU before consuming
629 * all its available runtime during the last job.
630 *
631 * @dl_non_contending tells if the task is inactive while still
632 * contributing to the active utilization. In other words, it
633 * indicates if the inactive timer has been armed and its handler
634 * has not been executed yet. This flag is useful to avoid race
635 * conditions between the inactive timer handler and the wakeup
636 * code.
637 *
638 * @dl_overrun tells if the task asked to be informed about runtime
639 * overruns.
640 */
641 unsigned int dl_throttled : 1;
642 unsigned int dl_yielded : 1;
643 unsigned int dl_non_contending : 1;
644 unsigned int dl_overrun : 1;
645 unsigned int dl_server : 1;
646
647 /*
648 * Bandwidth enforcement timer. Each -deadline task has its
649 * own bandwidth to be enforced, thus we need one timer per task.
650 */
651 struct hrtimer dl_timer;
652
653 /*
654 * Inactive timer, responsible for decreasing the active utilization
655 * at the "0-lag time". When a -deadline task blocks, it contributes
656 * to GRUB's active utilization until the "0-lag time", hence a
657 * timer is needed to decrease the active utilization at the correct
658 * time.
659 */
660 struct hrtimer inactive_timer;
661
662 /*
663 * Bits for DL-server functionality. Also see the comment near
664 * dl_server_update().
665 *
666 * @rq the runqueue this server is for
667 *
668 * @server_has_tasks() returns true if @server_pick return a
669 * runnable task.
670 */
671 struct rq *rq;
672 dl_server_has_tasks_f server_has_tasks;
673 dl_server_pick_f server_pick;
674
675 #ifdef CONFIG_RT_MUTEXES
676 /*
677 * Priority Inheritance. When a DEADLINE scheduling entity is boosted
678 * pi_se points to the donor, otherwise points to the dl_se it belongs
679 * to (the original one/itself).
680 */
681 struct sched_dl_entity *pi_se;
682 #endif
683 };
684
685 #ifdef CONFIG_UCLAMP_TASK
686 /* Number of utilization clamp buckets (shorter alias) */
687 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT
688
689 /*
690 * Utilization clamp for a scheduling entity
691 * @value: clamp value "assigned" to a se
692 * @bucket_id: bucket index corresponding to the "assigned" value
693 * @active: the se is currently refcounted in a rq's bucket
694 * @user_defined: the requested clamp value comes from user-space
695 *
696 * The bucket_id is the index of the clamp bucket matching the clamp value
697 * which is pre-computed and stored to avoid expensive integer divisions from
698 * the fast path.
699 *
700 * The active bit is set whenever a task has got an "effective" value assigned,
701 * which can be different from the clamp value "requested" from user-space.
702 * This allows to know a task is refcounted in the rq's bucket corresponding
703 * to the "effective" bucket_id.
704 *
705 * The user_defined bit is set whenever a task has got a task-specific clamp
706 * value requested from userspace, i.e. the system defaults apply to this task
707 * just as a restriction. This allows to relax default clamps when a less
708 * restrictive task-specific value has been requested, thus allowing to
709 * implement a "nice" semantic. For example, a task running with a 20%
710 * default boost can still drop its own boosting to 0%.
711 */
712 struct uclamp_se {
713 unsigned int value : bits_per(SCHED_CAPACITY_SCALE);
714 unsigned int bucket_id : bits_per(UCLAMP_BUCKETS);
715 unsigned int active : 1;
716 unsigned int user_defined : 1;
717 };
718 #endif /* CONFIG_UCLAMP_TASK */
719
720 union rcu_special {
721 struct {
722 u8 blocked;
723 u8 need_qs;
724 u8 exp_hint; /* Hint for performance. */
725 u8 need_mb; /* Readers need smp_mb(). */
726 } b; /* Bits. */
727 u32 s; /* Set of bits. */
728 };
729
730 enum perf_event_task_context {
731 perf_invalid_context = -1,
732 perf_hw_context = 0,
733 perf_sw_context,
734 perf_nr_task_contexts,
735 };
736
737 struct wake_q_node {
738 struct wake_q_node *next;
739 };
740
741 struct kmap_ctrl {
742 #ifdef CONFIG_KMAP_LOCAL
743 int idx;
744 pte_t pteval[KM_MAX_IDX];
745 #endif
746 };
747
748 struct task_struct {
749 #ifdef CONFIG_THREAD_INFO_IN_TASK
750 /*
751 * For reasons of header soup (see current_thread_info()), this
752 * must be the first element of task_struct.
753 */
754 struct thread_info thread_info;
755 #endif
756 unsigned int __state;
757
758 /* saved state for "spinlock sleepers" */
759 unsigned int saved_state;
760
761 /*
762 * This begins the randomizable portion of task_struct. Only
763 * scheduling-critical items should be added above here.
764 */
765 randomized_struct_fields_start
766
767 void *stack;
768 refcount_t usage;
769 /* Per task flags (PF_*), defined further below: */
770 unsigned int flags;
771 unsigned int ptrace;
772
773 #ifdef CONFIG_SMP
774 int on_cpu;
775 struct __call_single_node wake_entry;
776 unsigned int wakee_flips;
777 unsigned long wakee_flip_decay_ts;
778 struct task_struct *last_wakee;
779
780 /*
781 * recent_used_cpu is initially set as the last CPU used by a task
782 * that wakes affine another task. Waker/wakee relationships can
783 * push tasks around a CPU where each wakeup moves to the next one.
784 * Tracking a recently used CPU allows a quick search for a recently
785 * used CPU that may be idle.
786 */
787 int recent_used_cpu;
788 int wake_cpu;
789 #endif
790 int on_rq;
791
792 int prio;
793 int static_prio;
794 int normal_prio;
795 unsigned int rt_priority;
796
797 struct sched_entity se;
798 struct sched_rt_entity rt;
799 struct sched_dl_entity dl;
800 struct sched_dl_entity *dl_server;
801 const struct sched_class *sched_class;
802
803 #ifdef CONFIG_SCHED_CORE
804 struct rb_node core_node;
805 unsigned long core_cookie;
806 unsigned int core_occupation;
807 #endif
808
809 #ifdef CONFIG_CGROUP_SCHED
810 struct task_group *sched_task_group;
811 #endif
812
813 #ifdef CONFIG_UCLAMP_TASK
814 /*
815 * Clamp values requested for a scheduling entity.
816 * Must be updated with task_rq_lock() held.
817 */
818 struct uclamp_se uclamp_req[UCLAMP_CNT];
819 /*
820 * Effective clamp values used for a scheduling entity.
821 * Must be updated with task_rq_lock() held.
822 */
823 struct uclamp_se uclamp[UCLAMP_CNT];
824 #endif
825
826 struct sched_statistics stats;
827
828 #ifdef CONFIG_PREEMPT_NOTIFIERS
829 /* List of struct preempt_notifier: */
830 struct hlist_head preempt_notifiers;
831 #endif
832
833 #ifdef CONFIG_BLK_DEV_IO_TRACE
834 unsigned int btrace_seq;
835 #endif
836
837 unsigned int policy;
838 int nr_cpus_allowed;
839 const cpumask_t *cpus_ptr;
840 cpumask_t *user_cpus_ptr;
841 cpumask_t cpus_mask;
842 void *migration_pending;
843 #ifdef CONFIG_SMP
844 unsigned short migration_disabled;
845 #endif
846 unsigned short migration_flags;
847
848 #ifdef CONFIG_PREEMPT_RCU
849 int rcu_read_lock_nesting;
850 union rcu_special rcu_read_unlock_special;
851 struct list_head rcu_node_entry;
852 struct rcu_node *rcu_blocked_node;
853 #endif /* #ifdef CONFIG_PREEMPT_RCU */
854
855 #ifdef CONFIG_TASKS_RCU
856 unsigned long rcu_tasks_nvcsw;
857 u8 rcu_tasks_holdout;
858 u8 rcu_tasks_idx;
859 int rcu_tasks_idle_cpu;
860 struct list_head rcu_tasks_holdout_list;
861 #endif /* #ifdef CONFIG_TASKS_RCU */
862
863 #ifdef CONFIG_TASKS_TRACE_RCU
864 int trc_reader_nesting;
865 int trc_ipi_to_cpu;
866 union rcu_special trc_reader_special;
867 struct list_head trc_holdout_list;
868 struct list_head trc_blkd_node;
869 int trc_blkd_cpu;
870 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
871
872 struct sched_info sched_info;
873
874 struct list_head tasks;
875 #ifdef CONFIG_SMP
876 struct plist_node pushable_tasks;
877 struct rb_node pushable_dl_tasks;
878 #endif
879
880 struct mm_struct *mm;
881 struct mm_struct *active_mm;
882 struct address_space *faults_disabled_mapping;
883
884 int exit_state;
885 int exit_code;
886 int exit_signal;
887 /* The signal sent when the parent dies: */
888 int pdeath_signal;
889 /* JOBCTL_*, siglock protected: */
890 unsigned long jobctl;
891
892 /* Used for emulating ABI behavior of previous Linux versions: */
893 unsigned int personality;
894
895 /* Scheduler bits, serialized by scheduler locks: */
896 unsigned sched_reset_on_fork:1;
897 unsigned sched_contributes_to_load:1;
898 unsigned sched_migrated:1;
899
900 /* Force alignment to the next boundary: */
901 unsigned :0;
902
903 /* Unserialized, strictly 'current' */
904
905 /*
906 * This field must not be in the scheduler word above due to wakelist
907 * queueing no longer being serialized by p->on_cpu. However:
908 *
909 * p->XXX = X; ttwu()
910 * schedule() if (p->on_rq && ..) // false
911 * smp_mb__after_spinlock(); if (smp_load_acquire(&p->on_cpu) && //true
912 * deactivate_task() ttwu_queue_wakelist())
913 * p->on_rq = 0; p->sched_remote_wakeup = Y;
914 *
915 * guarantees all stores of 'current' are visible before
916 * ->sched_remote_wakeup gets used, so it can be in this word.
917 */
918 unsigned sched_remote_wakeup:1;
919 #ifdef CONFIG_RT_MUTEXES
920 unsigned sched_rt_mutex:1;
921 #endif
922
923 /* Bit to tell TOMOYO we're in execve(): */
924 unsigned in_execve:1;
925 unsigned in_iowait:1;
926 #ifndef TIF_RESTORE_SIGMASK
927 unsigned restore_sigmask:1;
928 #endif
929 #ifdef CONFIG_MEMCG
930 unsigned in_user_fault:1;
931 #endif
932 #ifdef CONFIG_LRU_GEN
933 /* whether the LRU algorithm may apply to this access */
934 unsigned in_lru_fault:1;
935 #endif
936 #ifdef CONFIG_COMPAT_BRK
937 unsigned brk_randomized:1;
938 #endif
939 #ifdef CONFIG_CGROUPS
940 /* disallow userland-initiated cgroup migration */
941 unsigned no_cgroup_migration:1;
942 /* task is frozen/stopped (used by the cgroup freezer) */
943 unsigned frozen:1;
944 #endif
945 #ifdef CONFIG_BLK_CGROUP
946 unsigned use_memdelay:1;
947 #endif
948 #ifdef CONFIG_PSI
949 /* Stalled due to lack of memory */
950 unsigned in_memstall:1;
951 #endif
952 #ifdef CONFIG_PAGE_OWNER
953 /* Used by page_owner=on to detect recursion in page tracking. */
954 unsigned in_page_owner:1;
955 #endif
956 #ifdef CONFIG_EVENTFD
957 /* Recursion prevention for eventfd_signal() */
958 unsigned in_eventfd:1;
959 #endif
960 #ifdef CONFIG_ARCH_HAS_CPU_PASID
961 unsigned pasid_activated:1;
962 #endif
963 #ifdef CONFIG_CPU_SUP_INTEL
964 unsigned reported_split_lock:1;
965 #endif
966 #ifdef CONFIG_TASK_DELAY_ACCT
967 /* delay due to memory thrashing */
968 unsigned in_thrashing:1;
969 #endif
970
971 unsigned long atomic_flags; /* Flags requiring atomic access. */
972
973 struct restart_block restart_block;
974
975 pid_t pid;
976 pid_t tgid;
977
978 #ifdef CONFIG_STACKPROTECTOR
979 /* Canary value for the -fstack-protector GCC feature: */
980 unsigned long stack_canary;
981 #endif
982 /*
983 * Pointers to the (original) parent process, youngest child, younger sibling,
984 * older sibling, respectively. (p->father can be replaced with
985 * p->real_parent->pid)
986 */
987
988 /* Real parent process: */
989 struct task_struct __rcu *real_parent;
990
991 /* Recipient of SIGCHLD, wait4() reports: */
992 struct task_struct __rcu *parent;
993
994 /*
995 * Children/sibling form the list of natural children:
996 */
997 struct list_head children;
998 struct list_head sibling;
999 struct task_struct *group_leader;
1000
1001 /*
1002 * 'ptraced' is the list of tasks this task is using ptrace() on.
1003 *
1004 * This includes both natural children and PTRACE_ATTACH targets.
1005 * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
1006 */
1007 struct list_head ptraced;
1008 struct list_head ptrace_entry;
1009
1010 /* PID/PID hash table linkage. */
1011 struct pid *thread_pid;
1012 struct hlist_node pid_links[PIDTYPE_MAX];
1013 struct list_head thread_node;
1014
1015 struct completion *vfork_done;
1016
1017 /* CLONE_CHILD_SETTID: */
1018 int __user *set_child_tid;
1019
1020 /* CLONE_CHILD_CLEARTID: */
1021 int __user *clear_child_tid;
1022
1023 /* PF_KTHREAD | PF_IO_WORKER */
1024 void *worker_private;
1025
1026 u64 utime;
1027 u64 stime;
1028 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
1029 u64 utimescaled;
1030 u64 stimescaled;
1031 #endif
1032 u64 gtime;
1033 struct prev_cputime prev_cputime;
1034 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1035 struct vtime vtime;
1036 #endif
1037
1038 #ifdef CONFIG_NO_HZ_FULL
1039 atomic_t tick_dep_mask;
1040 #endif
1041 /* Context switch counts: */
1042 unsigned long nvcsw;
1043 unsigned long nivcsw;
1044
1045 /* Monotonic time in nsecs: */
1046 u64 start_time;
1047
1048 /* Boot based time in nsecs: */
1049 u64 start_boottime;
1050
1051 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
1052 unsigned long min_flt;
1053 unsigned long maj_flt;
1054
1055 /* Empty if CONFIG_POSIX_CPUTIMERS=n */
1056 struct posix_cputimers posix_cputimers;
1057
1058 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK
1059 struct posix_cputimers_work posix_cputimers_work;
1060 #endif
1061
1062 /* Process credentials: */
1063
1064 /* Tracer's credentials at attach: */
1065 const struct cred __rcu *ptracer_cred;
1066
1067 /* Objective and real subjective task credentials (COW): */
1068 const struct cred __rcu *real_cred;
1069
1070 /* Effective (overridable) subjective task credentials (COW): */
1071 const struct cred __rcu *cred;
1072
1073 #ifdef CONFIG_KEYS
1074 /* Cached requested key. */
1075 struct key *cached_requested_key;
1076 #endif
1077
1078 /*
1079 * executable name, excluding path.
1080 *
1081 * - normally initialized setup_new_exec()
1082 * - access it with [gs]et_task_comm()
1083 * - lock it with task_lock()
1084 */
1085 char comm[TASK_COMM_LEN];
1086
1087 struct nameidata *nameidata;
1088
1089 #ifdef CONFIG_SYSVIPC
1090 struct sysv_sem sysvsem;
1091 struct sysv_shm sysvshm;
1092 #endif
1093 #ifdef CONFIG_DETECT_HUNG_TASK
1094 unsigned long last_switch_count;
1095 unsigned long last_switch_time;
1096 #endif
1097 /* Filesystem information: */
1098 struct fs_struct *fs;
1099
1100 /* Open file information: */
1101 struct files_struct *files;
1102
1103 #ifdef CONFIG_IO_URING
1104 struct io_uring_task *io_uring;
1105 #endif
1106
1107 /* Namespaces: */
1108 struct nsproxy *nsproxy;
1109
1110 /* Signal handlers: */
1111 struct signal_struct *signal;
1112 struct sighand_struct __rcu *sighand;
1113 sigset_t blocked;
1114 sigset_t real_blocked;
1115 /* Restored if set_restore_sigmask() was used: */
1116 sigset_t saved_sigmask;
1117 struct sigpending pending;
1118 unsigned long sas_ss_sp;
1119 size_t sas_ss_size;
1120 unsigned int sas_ss_flags;
1121
1122 struct callback_head *task_works;
1123
1124 #ifdef CONFIG_AUDIT
1125 #ifdef CONFIG_AUDITSYSCALL
1126 struct audit_context *audit_context;
1127 #endif
1128 kuid_t loginuid;
1129 unsigned int sessionid;
1130 #endif
1131 struct seccomp seccomp;
1132 struct syscall_user_dispatch syscall_dispatch;
1133
1134 /* Thread group tracking: */
1135 u64 parent_exec_id;
1136 u64 self_exec_id;
1137
1138 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
1139 spinlock_t alloc_lock;
1140
1141 /* Protection of the PI data structures: */
1142 raw_spinlock_t pi_lock;
1143
1144 struct wake_q_node wake_q;
1145
1146 #ifdef CONFIG_RT_MUTEXES
1147 /* PI waiters blocked on a rt_mutex held by this task: */
1148 struct rb_root_cached pi_waiters;
1149 /* Updated under owner's pi_lock and rq lock */
1150 struct task_struct *pi_top_task;
1151 /* Deadlock detection and priority inheritance handling: */
1152 struct rt_mutex_waiter *pi_blocked_on;
1153 #endif
1154
1155 #ifdef CONFIG_DEBUG_MUTEXES
1156 /* Mutex deadlock detection: */
1157 struct mutex_waiter *blocked_on;
1158 #endif
1159
1160 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1161 int non_block_count;
1162 #endif
1163
1164 #ifdef CONFIG_TRACE_IRQFLAGS
1165 struct irqtrace_events irqtrace;
1166 unsigned int hardirq_threaded;
1167 u64 hardirq_chain_key;
1168 int softirqs_enabled;
1169 int softirq_context;
1170 int irq_config;
1171 #endif
1172 #ifdef CONFIG_PREEMPT_RT
1173 int softirq_disable_cnt;
1174 #endif
1175
1176 #ifdef CONFIG_LOCKDEP
1177 # define MAX_LOCK_DEPTH 48UL
1178 u64 curr_chain_key;
1179 int lockdep_depth;
1180 unsigned int lockdep_recursion;
1181 struct held_lock held_locks[MAX_LOCK_DEPTH];
1182 #endif
1183
1184 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP)
1185 unsigned int in_ubsan;
1186 #endif
1187
1188 /* Journalling filesystem info: */
1189 void *journal_info;
1190
1191 /* Stacked block device info: */
1192 struct bio_list *bio_list;
1193
1194 /* Stack plugging: */
1195 struct blk_plug *plug;
1196
1197 /* VM state: */
1198 struct reclaim_state *reclaim_state;
1199
1200 struct io_context *io_context;
1201
1202 #ifdef CONFIG_COMPACTION
1203 struct capture_control *capture_control;
1204 #endif
1205 /* Ptrace state: */
1206 unsigned long ptrace_message;
1207 kernel_siginfo_t *last_siginfo;
1208
1209 struct task_io_accounting ioac;
1210 #ifdef CONFIG_PSI
1211 /* Pressure stall state */
1212 unsigned int psi_flags;
1213 #endif
1214 #ifdef CONFIG_TASK_XACCT
1215 /* Accumulated RSS usage: */
1216 u64 acct_rss_mem1;
1217 /* Accumulated virtual memory usage: */
1218 u64 acct_vm_mem1;
1219 /* stime + utime since last update: */
1220 u64 acct_timexpd;
1221 #endif
1222 #ifdef CONFIG_CPUSETS
1223 /* Protected by ->alloc_lock: */
1224 nodemask_t mems_allowed;
1225 /* Sequence number to catch updates: */
1226 seqcount_spinlock_t mems_allowed_seq;
1227 int cpuset_mem_spread_rotor;
1228 int cpuset_slab_spread_rotor;
1229 #endif
1230 #ifdef CONFIG_CGROUPS
1231 /* Control Group info protected by css_set_lock: */
1232 struct css_set __rcu *cgroups;
1233 /* cg_list protected by css_set_lock and tsk->alloc_lock: */
1234 struct list_head cg_list;
1235 #endif
1236 #ifdef CONFIG_X86_CPU_RESCTRL
1237 u32 closid;
1238 u32 rmid;
1239 #endif
1240 #ifdef CONFIG_FUTEX
1241 struct robust_list_head __user *robust_list;
1242 #ifdef CONFIG_COMPAT
1243 struct compat_robust_list_head __user *compat_robust_list;
1244 #endif
1245 struct list_head pi_state_list;
1246 struct futex_pi_state *pi_state_cache;
1247 struct mutex futex_exit_mutex;
1248 unsigned int futex_state;
1249 #endif
1250 #ifdef CONFIG_PERF_EVENTS
1251 struct perf_event_context *perf_event_ctxp;
1252 struct mutex perf_event_mutex;
1253 struct list_head perf_event_list;
1254 #endif
1255 #ifdef CONFIG_DEBUG_PREEMPT
1256 unsigned long preempt_disable_ip;
1257 #endif
1258 #ifdef CONFIG_NUMA
1259 /* Protected by alloc_lock: */
1260 struct mempolicy *mempolicy;
1261 short il_prev;
1262 short pref_node_fork;
1263 #endif
1264 #ifdef CONFIG_NUMA_BALANCING
1265 int numa_scan_seq;
1266 unsigned int numa_scan_period;
1267 unsigned int numa_scan_period_max;
1268 int numa_preferred_nid;
1269 unsigned long numa_migrate_retry;
1270 /* Migration stamp: */
1271 u64 node_stamp;
1272 u64 last_task_numa_placement;
1273 u64 last_sum_exec_runtime;
1274 struct callback_head numa_work;
1275
1276 /*
1277 * This pointer is only modified for current in syscall and
1278 * pagefault context (and for tasks being destroyed), so it can be read
1279 * from any of the following contexts:
1280 * - RCU read-side critical section
1281 * - current->numa_group from everywhere
1282 * - task's runqueue locked, task not running
1283 */
1284 struct numa_group __rcu *numa_group;
1285
1286 /*
1287 * numa_faults is an array split into four regions:
1288 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1289 * in this precise order.
1290 *
1291 * faults_memory: Exponential decaying average of faults on a per-node
1292 * basis. Scheduling placement decisions are made based on these
1293 * counts. The values remain static for the duration of a PTE scan.
1294 * faults_cpu: Track the nodes the process was running on when a NUMA
1295 * hinting fault was incurred.
1296 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1297 * during the current scan window. When the scan completes, the counts
1298 * in faults_memory and faults_cpu decay and these values are copied.
1299 */
1300 unsigned long *numa_faults;
1301 unsigned long total_numa_faults;
1302
1303 /*
1304 * numa_faults_locality tracks if faults recorded during the last
1305 * scan window were remote/local or failed to migrate. The task scan
1306 * period is adapted based on the locality of the faults with different
1307 * weights depending on whether they were shared or private faults
1308 */
1309 unsigned long numa_faults_locality[3];
1310
1311 unsigned long numa_pages_migrated;
1312 #endif /* CONFIG_NUMA_BALANCING */
1313
1314 #ifdef CONFIG_RSEQ
1315 struct rseq __user *rseq;
1316 u32 rseq_len;
1317 u32 rseq_sig;
1318 /*
1319 * RmW on rseq_event_mask must be performed atomically
1320 * with respect to preemption.
1321 */
1322 unsigned long rseq_event_mask;
1323 #endif
1324
1325 #ifdef CONFIG_SCHED_MM_CID
1326 int mm_cid; /* Current cid in mm */
1327 int last_mm_cid; /* Most recent cid in mm */
1328 int migrate_from_cpu;
1329 int mm_cid_active; /* Whether cid bitmap is active */
1330 struct callback_head cid_work;
1331 #endif
1332
1333 struct tlbflush_unmap_batch tlb_ubc;
1334
1335 /* Cache last used pipe for splice(): */
1336 struct pipe_inode_info *splice_pipe;
1337
1338 struct page_frag task_frag;
1339
1340 #ifdef CONFIG_TASK_DELAY_ACCT
1341 struct task_delay_info *delays;
1342 #endif
1343
1344 #ifdef CONFIG_FAULT_INJECTION
1345 int make_it_fail;
1346 unsigned int fail_nth;
1347 #endif
1348 /*
1349 * When (nr_dirtied >= nr_dirtied_pause), it's time to call
1350 * balance_dirty_pages() for a dirty throttling pause:
1351 */
1352 int nr_dirtied;
1353 int nr_dirtied_pause;
1354 /* Start of a write-and-pause period: */
1355 unsigned long dirty_paused_when;
1356
1357 #ifdef CONFIG_LATENCYTOP
1358 int latency_record_count;
1359 struct latency_record latency_record[LT_SAVECOUNT];
1360 #endif
1361 /*
1362 * Time slack values; these are used to round up poll() and
1363 * select() etc timeout values. These are in nanoseconds.
1364 */
1365 u64 timer_slack_ns;
1366 u64 default_timer_slack_ns;
1367
1368 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
1369 unsigned int kasan_depth;
1370 #endif
1371
1372 #ifdef CONFIG_KCSAN
1373 struct kcsan_ctx kcsan_ctx;
1374 #ifdef CONFIG_TRACE_IRQFLAGS
1375 struct irqtrace_events kcsan_save_irqtrace;
1376 #endif
1377 #ifdef CONFIG_KCSAN_WEAK_MEMORY
1378 int kcsan_stack_depth;
1379 #endif
1380 #endif
1381
1382 #ifdef CONFIG_KMSAN
1383 struct kmsan_ctx kmsan_ctx;
1384 #endif
1385
1386 #if IS_ENABLED(CONFIG_KUNIT)
1387 struct kunit *kunit_test;
1388 #endif
1389
1390 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1391 /* Index of current stored address in ret_stack: */
1392 int curr_ret_stack;
1393 int curr_ret_depth;
1394
1395 /* Stack of return addresses for return function tracing: */
1396 struct ftrace_ret_stack *ret_stack;
1397
1398 /* Timestamp for last schedule: */
1399 unsigned long long ftrace_timestamp;
1400
1401 /*
1402 * Number of functions that haven't been traced
1403 * because of depth overrun:
1404 */
1405 atomic_t trace_overrun;
1406
1407 /* Pause tracing: */
1408 atomic_t tracing_graph_pause;
1409 #endif
1410
1411 #ifdef CONFIG_TRACING
1412 /* Bitmask and counter of trace recursion: */
1413 unsigned long trace_recursion;
1414 #endif /* CONFIG_TRACING */
1415
1416 #ifdef CONFIG_KCOV
1417 /* See kernel/kcov.c for more details. */
1418
1419 /* Coverage collection mode enabled for this task (0 if disabled): */
1420 unsigned int kcov_mode;
1421
1422 /* Size of the kcov_area: */
1423 unsigned int kcov_size;
1424
1425 /* Buffer for coverage collection: */
1426 void *kcov_area;
1427
1428 /* KCOV descriptor wired with this task or NULL: */
1429 struct kcov *kcov;
1430
1431 /* KCOV common handle for remote coverage collection: */
1432 u64 kcov_handle;
1433
1434 /* KCOV sequence number: */
1435 int kcov_sequence;
1436
1437 /* Collect coverage from softirq context: */
1438 unsigned int kcov_softirq;
1439 #endif
1440
1441 #ifdef CONFIG_MEMCG
1442 struct mem_cgroup *memcg_in_oom;
1443 gfp_t memcg_oom_gfp_mask;
1444 int memcg_oom_order;
1445
1446 /* Number of pages to reclaim on returning to userland: */
1447 unsigned int memcg_nr_pages_over_high;
1448
1449 /* Used by memcontrol for targeted memcg charge: */
1450 struct mem_cgroup *active_memcg;
1451 #endif
1452
1453 #ifdef CONFIG_MEMCG_KMEM
1454 struct obj_cgroup *objcg;
1455 #endif
1456
1457 #ifdef CONFIG_BLK_CGROUP
1458 struct gendisk *throttle_disk;
1459 #endif
1460
1461 #ifdef CONFIG_UPROBES
1462 struct uprobe_task *utask;
1463 #endif
1464 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1465 unsigned int sequential_io;
1466 unsigned int sequential_io_avg;
1467 #endif
1468 struct kmap_ctrl kmap_ctrl;
1469 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1470 unsigned long task_state_change;
1471 # ifdef CONFIG_PREEMPT_RT
1472 unsigned long saved_state_change;
1473 # endif
1474 #endif
1475 struct rcu_head rcu;
1476 refcount_t rcu_users;
1477 int pagefault_disabled;
1478 #ifdef CONFIG_MMU
1479 struct task_struct *oom_reaper_list;
1480 struct timer_list oom_reaper_timer;
1481 #endif
1482 #ifdef CONFIG_VMAP_STACK
1483 struct vm_struct *stack_vm_area;
1484 #endif
1485 #ifdef CONFIG_THREAD_INFO_IN_TASK
1486 /* A live task holds one reference: */
1487 refcount_t stack_refcount;
1488 #endif
1489 #ifdef CONFIG_LIVEPATCH
1490 int patch_state;
1491 #endif
1492 #ifdef CONFIG_SECURITY
1493 /* Used by LSM modules for access restriction: */
1494 void *security;
1495 #endif
1496 #ifdef CONFIG_BPF_SYSCALL
1497 /* Used by BPF task local storage */
1498 struct bpf_local_storage __rcu *bpf_storage;
1499 /* Used for BPF run context */
1500 struct bpf_run_ctx *bpf_ctx;
1501 #endif
1502
1503 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK
1504 unsigned long lowest_stack;
1505 unsigned long prev_lowest_stack;
1506 #endif
1507
1508 #ifdef CONFIG_X86_MCE
1509 void __user *mce_vaddr;
1510 __u64 mce_kflags;
1511 u64 mce_addr;
1512 __u64 mce_ripv : 1,
1513 mce_whole_page : 1,
1514 __mce_reserved : 62;
1515 struct callback_head mce_kill_me;
1516 int mce_count;
1517 #endif
1518
1519 #ifdef CONFIG_KRETPROBES
1520 struct llist_head kretprobe_instances;
1521 #endif
1522 #ifdef CONFIG_RETHOOK
1523 struct llist_head rethooks;
1524 #endif
1525
1526 #ifdef CONFIG_ARCH_HAS_PARANOID_L1D_FLUSH
1527 /*
1528 * If L1D flush is supported on mm context switch
1529 * then we use this callback head to queue kill work
1530 * to kill tasks that are not running on SMT disabled
1531 * cores
1532 */
1533 struct callback_head l1d_flush_kill;
1534 #endif
1535
1536 #ifdef CONFIG_RV
1537 /*
1538 * Per-task RV monitor. Nowadays fixed in RV_PER_TASK_MONITORS.
1539 * If we find justification for more monitors, we can think
1540 * about adding more or developing a dynamic method. So far,
1541 * none of these are justified.
1542 */
1543 union rv_task_monitor rv[RV_PER_TASK_MONITORS];
1544 #endif
1545
1546 #ifdef CONFIG_USER_EVENTS
1547 struct user_event_mm *user_event_mm;
1548 #endif
1549
1550 /*
1551 * New fields for task_struct should be added above here, so that
1552 * they are included in the randomized portion of task_struct.
1553 */
1554 randomized_struct_fields_end
1555
1556 /* CPU-specific state of this task: */
1557 struct thread_struct thread;
1558
1559 /*
1560 * WARNING: on x86, 'thread_struct' contains a variable-sized
1561 * structure. It *MUST* be at the end of 'task_struct'.
1562 *
1563 * Do not put anything below here!
1564 */
1565 };
1566
1567 #define TASK_REPORT_IDLE (TASK_REPORT + 1)
1568 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1)
1569
__task_state_index(unsigned int tsk_state,unsigned int tsk_exit_state)1570 static inline unsigned int __task_state_index(unsigned int tsk_state,
1571 unsigned int tsk_exit_state)
1572 {
1573 unsigned int state = (tsk_state | tsk_exit_state) & TASK_REPORT;
1574
1575 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX);
1576
1577 if ((tsk_state & TASK_IDLE) == TASK_IDLE)
1578 state = TASK_REPORT_IDLE;
1579
1580 /*
1581 * We're lying here, but rather than expose a completely new task state
1582 * to userspace, we can make this appear as if the task has gone through
1583 * a regular rt_mutex_lock() call.
1584 */
1585 if (tsk_state & TASK_RTLOCK_WAIT)
1586 state = TASK_UNINTERRUPTIBLE;
1587
1588 return fls(state);
1589 }
1590
task_state_index(struct task_struct * tsk)1591 static inline unsigned int task_state_index(struct task_struct *tsk)
1592 {
1593 return __task_state_index(READ_ONCE(tsk->__state), tsk->exit_state);
1594 }
1595
task_index_to_char(unsigned int state)1596 static inline char task_index_to_char(unsigned int state)
1597 {
1598 static const char state_char[] = "RSDTtXZPI";
1599
1600 BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1);
1601
1602 return state_char[state];
1603 }
1604
task_state_to_char(struct task_struct * tsk)1605 static inline char task_state_to_char(struct task_struct *tsk)
1606 {
1607 return task_index_to_char(task_state_index(tsk));
1608 }
1609
1610 extern struct pid *cad_pid;
1611
1612 /*
1613 * Per process flags
1614 */
1615 #define PF_VCPU 0x00000001 /* I'm a virtual CPU */
1616 #define PF_IDLE 0x00000002 /* I am an IDLE thread */
1617 #define PF_EXITING 0x00000004 /* Getting shut down */
1618 #define PF_POSTCOREDUMP 0x00000008 /* Coredumps should ignore this task */
1619 #define PF_IO_WORKER 0x00000010 /* Task is an IO worker */
1620 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */
1621 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */
1622 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */
1623 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */
1624 #define PF_DUMPCORE 0x00000200 /* Dumped core */
1625 #define PF_SIGNALED 0x00000400 /* Killed by a signal */
1626 #define PF_MEMALLOC 0x00000800 /* Allocating memory */
1627 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */
1628 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */
1629 #define PF_USER_WORKER 0x00004000 /* Kernel thread cloned from userspace thread */
1630 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */
1631 #define PF__HOLE__00010000 0x00010000
1632 #define PF_KSWAPD 0x00020000 /* I am kswapd */
1633 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocation requests will inherit GFP_NOFS */
1634 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocation requests will inherit GFP_NOIO */
1635 #define PF_LOCAL_THROTTLE 0x00100000 /* Throttle writes only against the bdi I write to,
1636 * I am cleaning dirty pages from some other bdi. */
1637 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */
1638 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */
1639 #define PF__HOLE__00800000 0x00800000
1640 #define PF__HOLE__01000000 0x01000000
1641 #define PF__HOLE__02000000 0x02000000
1642 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */
1643 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */
1644 #define PF_MEMALLOC_PIN 0x10000000 /* Allocation context constrained to zones which allow long term pinning. */
1645 #define PF__HOLE__20000000 0x20000000
1646 #define PF__HOLE__40000000 0x40000000
1647 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */
1648
1649 /*
1650 * Only the _current_ task can read/write to tsk->flags, but other
1651 * tasks can access tsk->flags in readonly mode for example
1652 * with tsk_used_math (like during threaded core dumping).
1653 * There is however an exception to this rule during ptrace
1654 * or during fork: the ptracer task is allowed to write to the
1655 * child->flags of its traced child (same goes for fork, the parent
1656 * can write to the child->flags), because we're guaranteed the
1657 * child is not running and in turn not changing child->flags
1658 * at the same time the parent does it.
1659 */
1660 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1661 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1662 #define clear_used_math() clear_stopped_child_used_math(current)
1663 #define set_used_math() set_stopped_child_used_math(current)
1664
1665 #define conditional_stopped_child_used_math(condition, child) \
1666 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1667
1668 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current)
1669
1670 #define copy_to_stopped_child_used_math(child) \
1671 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1672
1673 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1674 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1675 #define used_math() tsk_used_math(current)
1676
is_percpu_thread(void)1677 static __always_inline bool is_percpu_thread(void)
1678 {
1679 #ifdef CONFIG_SMP
1680 return (current->flags & PF_NO_SETAFFINITY) &&
1681 (current->nr_cpus_allowed == 1);
1682 #else
1683 return true;
1684 #endif
1685 }
1686
1687 /* Per-process atomic flags. */
1688 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */
1689 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */
1690 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */
1691 #define PFA_SPEC_SSB_DISABLE 3 /* Speculative Store Bypass disabled */
1692 #define PFA_SPEC_SSB_FORCE_DISABLE 4 /* Speculative Store Bypass force disabled*/
1693 #define PFA_SPEC_IB_DISABLE 5 /* Indirect branch speculation restricted */
1694 #define PFA_SPEC_IB_FORCE_DISABLE 6 /* Indirect branch speculation permanently restricted */
1695 #define PFA_SPEC_SSB_NOEXEC 7 /* Speculative Store Bypass clear on execve() */
1696
1697 #define TASK_PFA_TEST(name, func) \
1698 static inline bool task_##func(struct task_struct *p) \
1699 { return test_bit(PFA_##name, &p->atomic_flags); }
1700
1701 #define TASK_PFA_SET(name, func) \
1702 static inline void task_set_##func(struct task_struct *p) \
1703 { set_bit(PFA_##name, &p->atomic_flags); }
1704
1705 #define TASK_PFA_CLEAR(name, func) \
1706 static inline void task_clear_##func(struct task_struct *p) \
1707 { clear_bit(PFA_##name, &p->atomic_flags); }
1708
TASK_PFA_TEST(NO_NEW_PRIVS,no_new_privs)1709 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
1710 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
1711
1712 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
1713 TASK_PFA_SET(SPREAD_PAGE, spread_page)
1714 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
1715
1716 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
1717 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
1718 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
1719
1720 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable)
1721 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable)
1722 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable)
1723
1724 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1725 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1726 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1727
1728 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1729 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1730
1731 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable)
1732 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable)
1733 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable)
1734
1735 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1736 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1737
1738 static inline void
1739 current_restore_flags(unsigned long orig_flags, unsigned long flags)
1740 {
1741 current->flags &= ~flags;
1742 current->flags |= orig_flags & flags;
1743 }
1744
1745 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
1746 extern int task_can_attach(struct task_struct *p);
1747 extern int dl_bw_alloc(int cpu, u64 dl_bw);
1748 extern void dl_bw_free(int cpu, u64 dl_bw);
1749 #ifdef CONFIG_SMP
1750
1751 /* do_set_cpus_allowed() - consider using set_cpus_allowed_ptr() instead */
1752 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
1753
1754 /**
1755 * set_cpus_allowed_ptr - set CPU affinity mask of a task
1756 * @p: the task
1757 * @new_mask: CPU affinity mask
1758 *
1759 * Return: zero if successful, or a negative error code
1760 */
1761 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
1762 extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node);
1763 extern void release_user_cpus_ptr(struct task_struct *p);
1764 extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask);
1765 extern void force_compatible_cpus_allowed_ptr(struct task_struct *p);
1766 extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p);
1767 #else
do_set_cpus_allowed(struct task_struct * p,const struct cpumask * new_mask)1768 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
1769 {
1770 }
set_cpus_allowed_ptr(struct task_struct * p,const struct cpumask * new_mask)1771 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
1772 {
1773 if (!cpumask_test_cpu(0, new_mask))
1774 return -EINVAL;
1775 return 0;
1776 }
dup_user_cpus_ptr(struct task_struct * dst,struct task_struct * src,int node)1777 static inline int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node)
1778 {
1779 if (src->user_cpus_ptr)
1780 return -EINVAL;
1781 return 0;
1782 }
release_user_cpus_ptr(struct task_struct * p)1783 static inline void release_user_cpus_ptr(struct task_struct *p)
1784 {
1785 WARN_ON(p->user_cpus_ptr);
1786 }
1787
dl_task_check_affinity(struct task_struct * p,const struct cpumask * mask)1788 static inline int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask)
1789 {
1790 return 0;
1791 }
1792 #endif
1793
1794 extern int yield_to(struct task_struct *p, bool preempt);
1795 extern void set_user_nice(struct task_struct *p, long nice);
1796 extern int task_prio(const struct task_struct *p);
1797
1798 /**
1799 * task_nice - return the nice value of a given task.
1800 * @p: the task in question.
1801 *
1802 * Return: The nice value [ -20 ... 0 ... 19 ].
1803 */
task_nice(const struct task_struct * p)1804 static inline int task_nice(const struct task_struct *p)
1805 {
1806 return PRIO_TO_NICE((p)->static_prio);
1807 }
1808
1809 extern int can_nice(const struct task_struct *p, const int nice);
1810 extern int task_curr(const struct task_struct *p);
1811 extern int idle_cpu(int cpu);
1812 extern int available_idle_cpu(int cpu);
1813 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *);
1814 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *);
1815 extern void sched_set_fifo(struct task_struct *p);
1816 extern void sched_set_fifo_low(struct task_struct *p);
1817 extern void sched_set_normal(struct task_struct *p, int nice);
1818 extern int sched_setattr(struct task_struct *, const struct sched_attr *);
1819 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *);
1820 extern struct task_struct *idle_task(int cpu);
1821
1822 /**
1823 * is_idle_task - is the specified task an idle task?
1824 * @p: the task in question.
1825 *
1826 * Return: 1 if @p is an idle task. 0 otherwise.
1827 */
is_idle_task(const struct task_struct * p)1828 static __always_inline bool is_idle_task(const struct task_struct *p)
1829 {
1830 return !!(p->flags & PF_IDLE);
1831 }
1832
1833 extern struct task_struct *curr_task(int cpu);
1834 extern void ia64_set_curr_task(int cpu, struct task_struct *p);
1835
1836 void yield(void);
1837
1838 union thread_union {
1839 struct task_struct task;
1840 #ifndef CONFIG_THREAD_INFO_IN_TASK
1841 struct thread_info thread_info;
1842 #endif
1843 unsigned long stack[THREAD_SIZE/sizeof(long)];
1844 };
1845
1846 #ifndef CONFIG_THREAD_INFO_IN_TASK
1847 extern struct thread_info init_thread_info;
1848 #endif
1849
1850 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
1851
1852 #ifdef CONFIG_THREAD_INFO_IN_TASK
1853 # define task_thread_info(task) (&(task)->thread_info)
1854 #elif !defined(__HAVE_THREAD_FUNCTIONS)
1855 # define task_thread_info(task) ((struct thread_info *)(task)->stack)
1856 #endif
1857
1858 /*
1859 * find a task by one of its numerical ids
1860 *
1861 * find_task_by_pid_ns():
1862 * finds a task by its pid in the specified namespace
1863 * find_task_by_vpid():
1864 * finds a task by its virtual pid
1865 *
1866 * see also find_vpid() etc in include/linux/pid.h
1867 */
1868
1869 extern struct task_struct *find_task_by_vpid(pid_t nr);
1870 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns);
1871
1872 /*
1873 * find a task by its virtual pid and get the task struct
1874 */
1875 extern struct task_struct *find_get_task_by_vpid(pid_t nr);
1876
1877 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
1878 extern int wake_up_process(struct task_struct *tsk);
1879 extern void wake_up_new_task(struct task_struct *tsk);
1880
1881 #ifdef CONFIG_SMP
1882 extern void kick_process(struct task_struct *tsk);
1883 #else
kick_process(struct task_struct * tsk)1884 static inline void kick_process(struct task_struct *tsk) { }
1885 #endif
1886
1887 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
1888
set_task_comm(struct task_struct * tsk,const char * from)1889 static inline void set_task_comm(struct task_struct *tsk, const char *from)
1890 {
1891 __set_task_comm(tsk, from, false);
1892 }
1893
1894 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk);
1895 #define get_task_comm(buf, tsk) ({ \
1896 BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN); \
1897 __get_task_comm(buf, sizeof(buf), tsk); \
1898 })
1899
1900 #ifdef CONFIG_SMP
scheduler_ipi(void)1901 static __always_inline void scheduler_ipi(void)
1902 {
1903 /*
1904 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting
1905 * TIF_NEED_RESCHED remotely (for the first time) will also send
1906 * this IPI.
1907 */
1908 preempt_fold_need_resched();
1909 }
1910 #else
scheduler_ipi(void)1911 static inline void scheduler_ipi(void) { }
1912 #endif
1913
1914 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state);
1915
1916 /*
1917 * Set thread flags in other task's structures.
1918 * See asm/thread_info.h for TIF_xxxx flags available:
1919 */
set_tsk_thread_flag(struct task_struct * tsk,int flag)1920 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
1921 {
1922 set_ti_thread_flag(task_thread_info(tsk), flag);
1923 }
1924
clear_tsk_thread_flag(struct task_struct * tsk,int flag)1925 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1926 {
1927 clear_ti_thread_flag(task_thread_info(tsk), flag);
1928 }
1929
update_tsk_thread_flag(struct task_struct * tsk,int flag,bool value)1930 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag,
1931 bool value)
1932 {
1933 update_ti_thread_flag(task_thread_info(tsk), flag, value);
1934 }
1935
test_and_set_tsk_thread_flag(struct task_struct * tsk,int flag)1936 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
1937 {
1938 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
1939 }
1940
test_and_clear_tsk_thread_flag(struct task_struct * tsk,int flag)1941 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1942 {
1943 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
1944 }
1945
test_tsk_thread_flag(struct task_struct * tsk,int flag)1946 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
1947 {
1948 return test_ti_thread_flag(task_thread_info(tsk), flag);
1949 }
1950
set_tsk_need_resched(struct task_struct * tsk)1951 static inline void set_tsk_need_resched(struct task_struct *tsk)
1952 {
1953 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1954 }
1955
clear_tsk_need_resched(struct task_struct * tsk)1956 static inline void clear_tsk_need_resched(struct task_struct *tsk)
1957 {
1958 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1959 }
1960
test_tsk_need_resched(struct task_struct * tsk)1961 static inline int test_tsk_need_resched(struct task_struct *tsk)
1962 {
1963 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
1964 }
1965
1966 /*
1967 * cond_resched() and cond_resched_lock(): latency reduction via
1968 * explicit rescheduling in places that are safe. The return
1969 * value indicates whether a reschedule was done in fact.
1970 * cond_resched_lock() will drop the spinlock before scheduling,
1971 */
1972 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC)
1973 extern int __cond_resched(void);
1974
1975 #if defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL)
1976
1977 void sched_dynamic_klp_enable(void);
1978 void sched_dynamic_klp_disable(void);
1979
1980 DECLARE_STATIC_CALL(cond_resched, __cond_resched);
1981
_cond_resched(void)1982 static __always_inline int _cond_resched(void)
1983 {
1984 return static_call_mod(cond_resched)();
1985 }
1986
1987 #elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY)
1988
1989 extern int dynamic_cond_resched(void);
1990
_cond_resched(void)1991 static __always_inline int _cond_resched(void)
1992 {
1993 return dynamic_cond_resched();
1994 }
1995
1996 #else /* !CONFIG_PREEMPTION */
1997
_cond_resched(void)1998 static inline int _cond_resched(void)
1999 {
2000 klp_sched_try_switch();
2001 return __cond_resched();
2002 }
2003
2004 #endif /* PREEMPT_DYNAMIC && CONFIG_HAVE_PREEMPT_DYNAMIC_CALL */
2005
2006 #else /* CONFIG_PREEMPTION && !CONFIG_PREEMPT_DYNAMIC */
2007
_cond_resched(void)2008 static inline int _cond_resched(void)
2009 {
2010 klp_sched_try_switch();
2011 return 0;
2012 }
2013
2014 #endif /* !CONFIG_PREEMPTION || CONFIG_PREEMPT_DYNAMIC */
2015
2016 #define cond_resched() ({ \
2017 __might_resched(__FILE__, __LINE__, 0); \
2018 _cond_resched(); \
2019 })
2020
2021 extern int __cond_resched_lock(spinlock_t *lock);
2022 extern int __cond_resched_rwlock_read(rwlock_t *lock);
2023 extern int __cond_resched_rwlock_write(rwlock_t *lock);
2024
2025 #define MIGHT_RESCHED_RCU_SHIFT 8
2026 #define MIGHT_RESCHED_PREEMPT_MASK ((1U << MIGHT_RESCHED_RCU_SHIFT) - 1)
2027
2028 #ifndef CONFIG_PREEMPT_RT
2029 /*
2030 * Non RT kernels have an elevated preempt count due to the held lock,
2031 * but are not allowed to be inside a RCU read side critical section
2032 */
2033 # define PREEMPT_LOCK_RESCHED_OFFSETS PREEMPT_LOCK_OFFSET
2034 #else
2035 /*
2036 * spin/rw_lock() on RT implies rcu_read_lock(). The might_sleep() check in
2037 * cond_resched*lock() has to take that into account because it checks for
2038 * preempt_count() and rcu_preempt_depth().
2039 */
2040 # define PREEMPT_LOCK_RESCHED_OFFSETS \
2041 (PREEMPT_LOCK_OFFSET + (1U << MIGHT_RESCHED_RCU_SHIFT))
2042 #endif
2043
2044 #define cond_resched_lock(lock) ({ \
2045 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \
2046 __cond_resched_lock(lock); \
2047 })
2048
2049 #define cond_resched_rwlock_read(lock) ({ \
2050 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \
2051 __cond_resched_rwlock_read(lock); \
2052 })
2053
2054 #define cond_resched_rwlock_write(lock) ({ \
2055 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \
2056 __cond_resched_rwlock_write(lock); \
2057 })
2058
2059 #ifdef CONFIG_PREEMPT_DYNAMIC
2060
2061 extern bool preempt_model_none(void);
2062 extern bool preempt_model_voluntary(void);
2063 extern bool preempt_model_full(void);
2064
2065 #else
2066
preempt_model_none(void)2067 static inline bool preempt_model_none(void)
2068 {
2069 return IS_ENABLED(CONFIG_PREEMPT_NONE);
2070 }
preempt_model_voluntary(void)2071 static inline bool preempt_model_voluntary(void)
2072 {
2073 return IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY);
2074 }
preempt_model_full(void)2075 static inline bool preempt_model_full(void)
2076 {
2077 return IS_ENABLED(CONFIG_PREEMPT);
2078 }
2079
2080 #endif
2081
preempt_model_rt(void)2082 static inline bool preempt_model_rt(void)
2083 {
2084 return IS_ENABLED(CONFIG_PREEMPT_RT);
2085 }
2086
2087 /*
2088 * Does the preemption model allow non-cooperative preemption?
2089 *
2090 * For !CONFIG_PREEMPT_DYNAMIC kernels this is an exact match with
2091 * CONFIG_PREEMPTION; for CONFIG_PREEMPT_DYNAMIC this doesn't work as the
2092 * kernel is *built* with CONFIG_PREEMPTION=y but may run with e.g. the
2093 * PREEMPT_NONE model.
2094 */
preempt_model_preemptible(void)2095 static inline bool preempt_model_preemptible(void)
2096 {
2097 return preempt_model_full() || preempt_model_rt();
2098 }
2099
need_resched(void)2100 static __always_inline bool need_resched(void)
2101 {
2102 return unlikely(tif_need_resched());
2103 }
2104
2105 /*
2106 * Wrappers for p->thread_info->cpu access. No-op on UP.
2107 */
2108 #ifdef CONFIG_SMP
2109
task_cpu(const struct task_struct * p)2110 static inline unsigned int task_cpu(const struct task_struct *p)
2111 {
2112 return READ_ONCE(task_thread_info(p)->cpu);
2113 }
2114
2115 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2116
2117 #else
2118
task_cpu(const struct task_struct * p)2119 static inline unsigned int task_cpu(const struct task_struct *p)
2120 {
2121 return 0;
2122 }
2123
set_task_cpu(struct task_struct * p,unsigned int cpu)2124 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2125 {
2126 }
2127
2128 #endif /* CONFIG_SMP */
2129
2130 extern bool sched_task_on_rq(struct task_struct *p);
2131 extern unsigned long get_wchan(struct task_struct *p);
2132 extern struct task_struct *cpu_curr_snapshot(int cpu);
2133
2134 #include <linux/spinlock.h>
2135
2136 /*
2137 * In order to reduce various lock holder preemption latencies provide an
2138 * interface to see if a vCPU is currently running or not.
2139 *
2140 * This allows us to terminate optimistic spin loops and block, analogous to
2141 * the native optimistic spin heuristic of testing if the lock owner task is
2142 * running or not.
2143 */
2144 #ifndef vcpu_is_preempted
vcpu_is_preempted(int cpu)2145 static inline bool vcpu_is_preempted(int cpu)
2146 {
2147 return false;
2148 }
2149 #endif
2150
2151 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2152 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2153
2154 #ifndef TASK_SIZE_OF
2155 #define TASK_SIZE_OF(tsk) TASK_SIZE
2156 #endif
2157
2158 #ifdef CONFIG_SMP
owner_on_cpu(struct task_struct * owner)2159 static inline bool owner_on_cpu(struct task_struct *owner)
2160 {
2161 /*
2162 * As lock holder preemption issue, we both skip spinning if
2163 * task is not on cpu or its cpu is preempted
2164 */
2165 return READ_ONCE(owner->on_cpu) && !vcpu_is_preempted(task_cpu(owner));
2166 }
2167
2168 /* Returns effective CPU energy utilization, as seen by the scheduler */
2169 unsigned long sched_cpu_util(int cpu);
2170 #endif /* CONFIG_SMP */
2171
2172 #ifdef CONFIG_SCHED_CORE
2173 extern void sched_core_free(struct task_struct *tsk);
2174 extern void sched_core_fork(struct task_struct *p);
2175 extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type,
2176 unsigned long uaddr);
2177 extern int sched_core_idle_cpu(int cpu);
2178 #else
sched_core_free(struct task_struct * tsk)2179 static inline void sched_core_free(struct task_struct *tsk) { }
sched_core_fork(struct task_struct * p)2180 static inline void sched_core_fork(struct task_struct *p) { }
sched_core_idle_cpu(int cpu)2181 static inline int sched_core_idle_cpu(int cpu) { return idle_cpu(cpu); }
2182 #endif
2183
2184 extern void sched_set_stop_task(int cpu, struct task_struct *stop);
2185
2186 #endif
2187