1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_SCHED_H
3 #define _LINUX_SCHED_H
4
5 /*
6 * Define 'struct task_struct' and provide the main scheduler
7 * APIs (schedule(), wakeup variants, etc.)
8 */
9
10 #include <uapi/linux/sched.h>
11
12 #include <asm/current.h>
13
14 #include <linux/pid.h>
15 #include <linux/sem.h>
16 #include <linux/shm.h>
17 #include <linux/kmsan_types.h>
18 #include <linux/mutex.h>
19 #include <linux/plist.h>
20 #include <linux/hrtimer.h>
21 #include <linux/irqflags.h>
22 #include <linux/seccomp.h>
23 #include <linux/nodemask.h>
24 #include <linux/rcupdate.h>
25 #include <linux/refcount.h>
26 #include <linux/resource.h>
27 #include <linux/latencytop.h>
28 #include <linux/sched/prio.h>
29 #include <linux/sched/types.h>
30 #include <linux/signal_types.h>
31 #include <linux/syscall_user_dispatch.h>
32 #include <linux/mm_types_task.h>
33 #include <linux/task_io_accounting.h>
34 #include <linux/posix-timers.h>
35 #include <linux/rseq.h>
36 #include <linux/seqlock.h>
37 #include <linux/kcsan.h>
38 #include <linux/rv.h>
39 #include <asm/kmap_size.h>
40
41 /* task_struct member predeclarations (sorted alphabetically): */
42 struct audit_context;
43 struct backing_dev_info;
44 struct bio_list;
45 struct blk_plug;
46 struct bpf_local_storage;
47 struct bpf_run_ctx;
48 struct capture_control;
49 struct cfs_rq;
50 struct fs_struct;
51 struct futex_pi_state;
52 struct io_context;
53 struct io_uring_task;
54 struct mempolicy;
55 struct nameidata;
56 struct nsproxy;
57 struct perf_event_context;
58 struct pid_namespace;
59 struct pipe_inode_info;
60 struct rcu_node;
61 struct reclaim_state;
62 struct robust_list_head;
63 struct root_domain;
64 struct rq;
65 struct sched_attr;
66 struct sched_param;
67 struct seq_file;
68 struct sighand_struct;
69 struct signal_struct;
70 struct task_delay_info;
71 struct task_group;
72
73 /*
74 * Task state bitmask. NOTE! These bits are also
75 * encoded in fs/proc/array.c: get_task_state().
76 *
77 * We have two separate sets of flags: task->state
78 * is about runnability, while task->exit_state are
79 * about the task exiting. Confusing, but this way
80 * modifying one set can't modify the other one by
81 * mistake.
82 */
83
84 /* Used in tsk->state: */
85 #define TASK_RUNNING 0x00000000
86 #define TASK_INTERRUPTIBLE 0x00000001
87 #define TASK_UNINTERRUPTIBLE 0x00000002
88 #define __TASK_STOPPED 0x00000004
89 #define __TASK_TRACED 0x00000008
90 /* Used in tsk->exit_state: */
91 #define EXIT_DEAD 0x00000010
92 #define EXIT_ZOMBIE 0x00000020
93 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD)
94 /* Used in tsk->state again: */
95 #define TASK_PARKED 0x00000040
96 #define TASK_DEAD 0x00000080
97 #define TASK_WAKEKILL 0x00000100
98 #define TASK_WAKING 0x00000200
99 #define TASK_NOLOAD 0x00000400
100 #define TASK_NEW 0x00000800
101 #define TASK_RTLOCK_WAIT 0x00001000
102 #define TASK_FREEZABLE 0x00002000
103 #define __TASK_FREEZABLE_UNSAFE (0x00004000 * IS_ENABLED(CONFIG_LOCKDEP))
104 #define TASK_FROZEN 0x00008000
105 #define TASK_STATE_MAX 0x00010000
106
107 #define TASK_ANY (TASK_STATE_MAX-1)
108
109 /*
110 * DO NOT ADD ANY NEW USERS !
111 */
112 #define TASK_FREEZABLE_UNSAFE (TASK_FREEZABLE | __TASK_FREEZABLE_UNSAFE)
113
114 /* Convenience macros for the sake of set_current_state: */
115 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
116 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED)
117 #define TASK_TRACED __TASK_TRACED
118
119 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
120
121 /* Convenience macros for the sake of wake_up(): */
122 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
123
124 /* get_task_state(): */
125 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \
126 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
127 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
128 TASK_PARKED)
129
130 #define task_is_running(task) (READ_ONCE((task)->__state) == TASK_RUNNING)
131
132 #define task_is_traced(task) ((READ_ONCE(task->jobctl) & JOBCTL_TRACED) != 0)
133 #define task_is_stopped(task) ((READ_ONCE(task->jobctl) & JOBCTL_STOPPED) != 0)
134 #define task_is_stopped_or_traced(task) ((READ_ONCE(task->jobctl) & (JOBCTL_STOPPED | JOBCTL_TRACED)) != 0)
135
136 /*
137 * Special states are those that do not use the normal wait-loop pattern. See
138 * the comment with set_special_state().
139 */
140 #define is_special_task_state(state) \
141 ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD))
142
143 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
144 # define debug_normal_state_change(state_value) \
145 do { \
146 WARN_ON_ONCE(is_special_task_state(state_value)); \
147 current->task_state_change = _THIS_IP_; \
148 } while (0)
149
150 # define debug_special_state_change(state_value) \
151 do { \
152 WARN_ON_ONCE(!is_special_task_state(state_value)); \
153 current->task_state_change = _THIS_IP_; \
154 } while (0)
155
156 # define debug_rtlock_wait_set_state() \
157 do { \
158 current->saved_state_change = current->task_state_change;\
159 current->task_state_change = _THIS_IP_; \
160 } while (0)
161
162 # define debug_rtlock_wait_restore_state() \
163 do { \
164 current->task_state_change = current->saved_state_change;\
165 } while (0)
166
167 #else
168 # define debug_normal_state_change(cond) do { } while (0)
169 # define debug_special_state_change(cond) do { } while (0)
170 # define debug_rtlock_wait_set_state() do { } while (0)
171 # define debug_rtlock_wait_restore_state() do { } while (0)
172 #endif
173
174 /*
175 * set_current_state() includes a barrier so that the write of current->state
176 * is correctly serialised wrt the caller's subsequent test of whether to
177 * actually sleep:
178 *
179 * for (;;) {
180 * set_current_state(TASK_UNINTERRUPTIBLE);
181 * if (CONDITION)
182 * break;
183 *
184 * schedule();
185 * }
186 * __set_current_state(TASK_RUNNING);
187 *
188 * If the caller does not need such serialisation (because, for instance, the
189 * CONDITION test and condition change and wakeup are under the same lock) then
190 * use __set_current_state().
191 *
192 * The above is typically ordered against the wakeup, which does:
193 *
194 * CONDITION = 1;
195 * wake_up_state(p, TASK_UNINTERRUPTIBLE);
196 *
197 * where wake_up_state()/try_to_wake_up() executes a full memory barrier before
198 * accessing p->state.
199 *
200 * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is,
201 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
202 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
203 *
204 * However, with slightly different timing the wakeup TASK_RUNNING store can
205 * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not
206 * a problem either because that will result in one extra go around the loop
207 * and our @cond test will save the day.
208 *
209 * Also see the comments of try_to_wake_up().
210 */
211 #define __set_current_state(state_value) \
212 do { \
213 debug_normal_state_change((state_value)); \
214 WRITE_ONCE(current->__state, (state_value)); \
215 } while (0)
216
217 #define set_current_state(state_value) \
218 do { \
219 debug_normal_state_change((state_value)); \
220 smp_store_mb(current->__state, (state_value)); \
221 } while (0)
222
223 /*
224 * set_special_state() should be used for those states when the blocking task
225 * can not use the regular condition based wait-loop. In that case we must
226 * serialize against wakeups such that any possible in-flight TASK_RUNNING
227 * stores will not collide with our state change.
228 */
229 #define set_special_state(state_value) \
230 do { \
231 unsigned long flags; /* may shadow */ \
232 \
233 raw_spin_lock_irqsave(¤t->pi_lock, flags); \
234 debug_special_state_change((state_value)); \
235 WRITE_ONCE(current->__state, (state_value)); \
236 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \
237 } while (0)
238
239 /*
240 * PREEMPT_RT specific variants for "sleeping" spin/rwlocks
241 *
242 * RT's spin/rwlock substitutions are state preserving. The state of the
243 * task when blocking on the lock is saved in task_struct::saved_state and
244 * restored after the lock has been acquired. These operations are
245 * serialized by task_struct::pi_lock against try_to_wake_up(). Any non RT
246 * lock related wakeups while the task is blocked on the lock are
247 * redirected to operate on task_struct::saved_state to ensure that these
248 * are not dropped. On restore task_struct::saved_state is set to
249 * TASK_RUNNING so any wakeup attempt redirected to saved_state will fail.
250 *
251 * The lock operation looks like this:
252 *
253 * current_save_and_set_rtlock_wait_state();
254 * for (;;) {
255 * if (try_lock())
256 * break;
257 * raw_spin_unlock_irq(&lock->wait_lock);
258 * schedule_rtlock();
259 * raw_spin_lock_irq(&lock->wait_lock);
260 * set_current_state(TASK_RTLOCK_WAIT);
261 * }
262 * current_restore_rtlock_saved_state();
263 */
264 #define current_save_and_set_rtlock_wait_state() \
265 do { \
266 lockdep_assert_irqs_disabled(); \
267 raw_spin_lock(¤t->pi_lock); \
268 current->saved_state = current->__state; \
269 debug_rtlock_wait_set_state(); \
270 WRITE_ONCE(current->__state, TASK_RTLOCK_WAIT); \
271 raw_spin_unlock(¤t->pi_lock); \
272 } while (0);
273
274 #define current_restore_rtlock_saved_state() \
275 do { \
276 lockdep_assert_irqs_disabled(); \
277 raw_spin_lock(¤t->pi_lock); \
278 debug_rtlock_wait_restore_state(); \
279 WRITE_ONCE(current->__state, current->saved_state); \
280 current->saved_state = TASK_RUNNING; \
281 raw_spin_unlock(¤t->pi_lock); \
282 } while (0);
283
284 #define get_current_state() READ_ONCE(current->__state)
285
286 /*
287 * Define the task command name length as enum, then it can be visible to
288 * BPF programs.
289 */
290 enum {
291 TASK_COMM_LEN = 16,
292 };
293
294 extern void scheduler_tick(void);
295
296 #define MAX_SCHEDULE_TIMEOUT LONG_MAX
297
298 extern long schedule_timeout(long timeout);
299 extern long schedule_timeout_interruptible(long timeout);
300 extern long schedule_timeout_killable(long timeout);
301 extern long schedule_timeout_uninterruptible(long timeout);
302 extern long schedule_timeout_idle(long timeout);
303 asmlinkage void schedule(void);
304 extern void schedule_preempt_disabled(void);
305 asmlinkage void preempt_schedule_irq(void);
306 #ifdef CONFIG_PREEMPT_RT
307 extern void schedule_rtlock(void);
308 #endif
309
310 extern int __must_check io_schedule_prepare(void);
311 extern void io_schedule_finish(int token);
312 extern long io_schedule_timeout(long timeout);
313 extern void io_schedule(void);
314
315 /**
316 * struct prev_cputime - snapshot of system and user cputime
317 * @utime: time spent in user mode
318 * @stime: time spent in system mode
319 * @lock: protects the above two fields
320 *
321 * Stores previous user/system time values such that we can guarantee
322 * monotonicity.
323 */
324 struct prev_cputime {
325 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
326 u64 utime;
327 u64 stime;
328 raw_spinlock_t lock;
329 #endif
330 };
331
332 enum vtime_state {
333 /* Task is sleeping or running in a CPU with VTIME inactive: */
334 VTIME_INACTIVE = 0,
335 /* Task is idle */
336 VTIME_IDLE,
337 /* Task runs in kernelspace in a CPU with VTIME active: */
338 VTIME_SYS,
339 /* Task runs in userspace in a CPU with VTIME active: */
340 VTIME_USER,
341 /* Task runs as guests in a CPU with VTIME active: */
342 VTIME_GUEST,
343 };
344
345 struct vtime {
346 seqcount_t seqcount;
347 unsigned long long starttime;
348 enum vtime_state state;
349 unsigned int cpu;
350 u64 utime;
351 u64 stime;
352 u64 gtime;
353 };
354
355 /*
356 * Utilization clamp constraints.
357 * @UCLAMP_MIN: Minimum utilization
358 * @UCLAMP_MAX: Maximum utilization
359 * @UCLAMP_CNT: Utilization clamp constraints count
360 */
361 enum uclamp_id {
362 UCLAMP_MIN = 0,
363 UCLAMP_MAX,
364 UCLAMP_CNT
365 };
366
367 #ifdef CONFIG_SMP
368 extern struct root_domain def_root_domain;
369 extern struct mutex sched_domains_mutex;
370 #endif
371
372 struct sched_info {
373 #ifdef CONFIG_SCHED_INFO
374 /* Cumulative counters: */
375
376 /* # of times we have run on this CPU: */
377 unsigned long pcount;
378
379 /* Time spent waiting on a runqueue: */
380 unsigned long long run_delay;
381
382 /* Timestamps: */
383
384 /* When did we last run on a CPU? */
385 unsigned long long last_arrival;
386
387 /* When were we last queued to run? */
388 unsigned long long last_queued;
389
390 #endif /* CONFIG_SCHED_INFO */
391 };
392
393 /*
394 * Integer metrics need fixed point arithmetic, e.g., sched/fair
395 * has a few: load, load_avg, util_avg, freq, and capacity.
396 *
397 * We define a basic fixed point arithmetic range, and then formalize
398 * all these metrics based on that basic range.
399 */
400 # define SCHED_FIXEDPOINT_SHIFT 10
401 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT)
402
403 /* Increase resolution of cpu_capacity calculations */
404 # define SCHED_CAPACITY_SHIFT SCHED_FIXEDPOINT_SHIFT
405 # define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT)
406
407 struct load_weight {
408 unsigned long weight;
409 u32 inv_weight;
410 };
411
412 /**
413 * struct util_est - Estimation utilization of FAIR tasks
414 * @enqueued: instantaneous estimated utilization of a task/cpu
415 * @ewma: the Exponential Weighted Moving Average (EWMA)
416 * utilization of a task
417 *
418 * Support data structure to track an Exponential Weighted Moving Average
419 * (EWMA) of a FAIR task's utilization. New samples are added to the moving
420 * average each time a task completes an activation. Sample's weight is chosen
421 * so that the EWMA will be relatively insensitive to transient changes to the
422 * task's workload.
423 *
424 * The enqueued attribute has a slightly different meaning for tasks and cpus:
425 * - task: the task's util_avg at last task dequeue time
426 * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU
427 * Thus, the util_est.enqueued of a task represents the contribution on the
428 * estimated utilization of the CPU where that task is currently enqueued.
429 *
430 * Only for tasks we track a moving average of the past instantaneous
431 * estimated utilization. This allows to absorb sporadic drops in utilization
432 * of an otherwise almost periodic task.
433 *
434 * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg
435 * updates. When a task is dequeued, its util_est should not be updated if its
436 * util_avg has not been updated in the meantime.
437 * This information is mapped into the MSB bit of util_est.enqueued at dequeue
438 * time. Since max value of util_est.enqueued for a task is 1024 (PELT util_avg
439 * for a task) it is safe to use MSB.
440 */
441 struct util_est {
442 unsigned int enqueued;
443 unsigned int ewma;
444 #define UTIL_EST_WEIGHT_SHIFT 2
445 #define UTIL_AVG_UNCHANGED 0x80000000
446 } __attribute__((__aligned__(sizeof(u64))));
447
448 /*
449 * The load/runnable/util_avg accumulates an infinite geometric series
450 * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c).
451 *
452 * [load_avg definition]
453 *
454 * load_avg = runnable% * scale_load_down(load)
455 *
456 * [runnable_avg definition]
457 *
458 * runnable_avg = runnable% * SCHED_CAPACITY_SCALE
459 *
460 * [util_avg definition]
461 *
462 * util_avg = running% * SCHED_CAPACITY_SCALE
463 *
464 * where runnable% is the time ratio that a sched_entity is runnable and
465 * running% the time ratio that a sched_entity is running.
466 *
467 * For cfs_rq, they are the aggregated values of all runnable and blocked
468 * sched_entities.
469 *
470 * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU
471 * capacity scaling. The scaling is done through the rq_clock_pelt that is used
472 * for computing those signals (see update_rq_clock_pelt())
473 *
474 * N.B., the above ratios (runnable% and running%) themselves are in the
475 * range of [0, 1]. To do fixed point arithmetics, we therefore scale them
476 * to as large a range as necessary. This is for example reflected by
477 * util_avg's SCHED_CAPACITY_SCALE.
478 *
479 * [Overflow issue]
480 *
481 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
482 * with the highest load (=88761), always runnable on a single cfs_rq,
483 * and should not overflow as the number already hits PID_MAX_LIMIT.
484 *
485 * For all other cases (including 32-bit kernels), struct load_weight's
486 * weight will overflow first before we do, because:
487 *
488 * Max(load_avg) <= Max(load.weight)
489 *
490 * Then it is the load_weight's responsibility to consider overflow
491 * issues.
492 */
493 struct sched_avg {
494 u64 last_update_time;
495 u64 load_sum;
496 u64 runnable_sum;
497 u32 util_sum;
498 u32 period_contrib;
499 unsigned long load_avg;
500 unsigned long runnable_avg;
501 unsigned long util_avg;
502 struct util_est util_est;
503 } ____cacheline_aligned;
504
505 struct sched_statistics {
506 #ifdef CONFIG_SCHEDSTATS
507 u64 wait_start;
508 u64 wait_max;
509 u64 wait_count;
510 u64 wait_sum;
511 u64 iowait_count;
512 u64 iowait_sum;
513
514 u64 sleep_start;
515 u64 sleep_max;
516 s64 sum_sleep_runtime;
517
518 u64 block_start;
519 u64 block_max;
520 s64 sum_block_runtime;
521
522 u64 exec_max;
523 u64 slice_max;
524
525 u64 nr_migrations_cold;
526 u64 nr_failed_migrations_affine;
527 u64 nr_failed_migrations_running;
528 u64 nr_failed_migrations_hot;
529 u64 nr_forced_migrations;
530
531 u64 nr_wakeups;
532 u64 nr_wakeups_sync;
533 u64 nr_wakeups_migrate;
534 u64 nr_wakeups_local;
535 u64 nr_wakeups_remote;
536 u64 nr_wakeups_affine;
537 u64 nr_wakeups_affine_attempts;
538 u64 nr_wakeups_passive;
539 u64 nr_wakeups_idle;
540
541 #ifdef CONFIG_SCHED_CORE
542 u64 core_forceidle_sum;
543 #endif
544 #endif /* CONFIG_SCHEDSTATS */
545 } ____cacheline_aligned;
546
547 struct sched_entity {
548 /* For load-balancing: */
549 struct load_weight load;
550 struct rb_node run_node;
551 struct list_head group_node;
552 unsigned int on_rq;
553
554 u64 exec_start;
555 u64 sum_exec_runtime;
556 u64 vruntime;
557 u64 prev_sum_exec_runtime;
558
559 u64 nr_migrations;
560
561 #ifdef CONFIG_FAIR_GROUP_SCHED
562 int depth;
563 struct sched_entity *parent;
564 /* rq on which this entity is (to be) queued: */
565 struct cfs_rq *cfs_rq;
566 /* rq "owned" by this entity/group: */
567 struct cfs_rq *my_q;
568 /* cached value of my_q->h_nr_running */
569 unsigned long runnable_weight;
570 #endif
571
572 #ifdef CONFIG_SMP
573 /*
574 * Per entity load average tracking.
575 *
576 * Put into separate cache line so it does not
577 * collide with read-mostly values above.
578 */
579 struct sched_avg avg;
580 #endif
581 };
582
583 struct sched_rt_entity {
584 struct list_head run_list;
585 unsigned long timeout;
586 unsigned long watchdog_stamp;
587 unsigned int time_slice;
588 unsigned short on_rq;
589 unsigned short on_list;
590
591 struct sched_rt_entity *back;
592 #ifdef CONFIG_RT_GROUP_SCHED
593 struct sched_rt_entity *parent;
594 /* rq on which this entity is (to be) queued: */
595 struct rt_rq *rt_rq;
596 /* rq "owned" by this entity/group: */
597 struct rt_rq *my_q;
598 #endif
599 } __randomize_layout;
600
601 struct sched_dl_entity {
602 struct rb_node rb_node;
603
604 /*
605 * Original scheduling parameters. Copied here from sched_attr
606 * during sched_setattr(), they will remain the same until
607 * the next sched_setattr().
608 */
609 u64 dl_runtime; /* Maximum runtime for each instance */
610 u64 dl_deadline; /* Relative deadline of each instance */
611 u64 dl_period; /* Separation of two instances (period) */
612 u64 dl_bw; /* dl_runtime / dl_period */
613 u64 dl_density; /* dl_runtime / dl_deadline */
614
615 /*
616 * Actual scheduling parameters. Initialized with the values above,
617 * they are continuously updated during task execution. Note that
618 * the remaining runtime could be < 0 in case we are in overrun.
619 */
620 s64 runtime; /* Remaining runtime for this instance */
621 u64 deadline; /* Absolute deadline for this instance */
622 unsigned int flags; /* Specifying the scheduler behaviour */
623
624 /*
625 * Some bool flags:
626 *
627 * @dl_throttled tells if we exhausted the runtime. If so, the
628 * task has to wait for a replenishment to be performed at the
629 * next firing of dl_timer.
630 *
631 * @dl_yielded tells if task gave up the CPU before consuming
632 * all its available runtime during the last job.
633 *
634 * @dl_non_contending tells if the task is inactive while still
635 * contributing to the active utilization. In other words, it
636 * indicates if the inactive timer has been armed and its handler
637 * has not been executed yet. This flag is useful to avoid race
638 * conditions between the inactive timer handler and the wakeup
639 * code.
640 *
641 * @dl_overrun tells if the task asked to be informed about runtime
642 * overruns.
643 */
644 unsigned int dl_throttled : 1;
645 unsigned int dl_yielded : 1;
646 unsigned int dl_non_contending : 1;
647 unsigned int dl_overrun : 1;
648
649 /*
650 * Bandwidth enforcement timer. Each -deadline task has its
651 * own bandwidth to be enforced, thus we need one timer per task.
652 */
653 struct hrtimer dl_timer;
654
655 /*
656 * Inactive timer, responsible for decreasing the active utilization
657 * at the "0-lag time". When a -deadline task blocks, it contributes
658 * to GRUB's active utilization until the "0-lag time", hence a
659 * timer is needed to decrease the active utilization at the correct
660 * time.
661 */
662 struct hrtimer inactive_timer;
663
664 #ifdef CONFIG_RT_MUTEXES
665 /*
666 * Priority Inheritance. When a DEADLINE scheduling entity is boosted
667 * pi_se points to the donor, otherwise points to the dl_se it belongs
668 * to (the original one/itself).
669 */
670 struct sched_dl_entity *pi_se;
671 #endif
672 };
673
674 #ifdef CONFIG_UCLAMP_TASK
675 /* Number of utilization clamp buckets (shorter alias) */
676 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT
677
678 /*
679 * Utilization clamp for a scheduling entity
680 * @value: clamp value "assigned" to a se
681 * @bucket_id: bucket index corresponding to the "assigned" value
682 * @active: the se is currently refcounted in a rq's bucket
683 * @user_defined: the requested clamp value comes from user-space
684 *
685 * The bucket_id is the index of the clamp bucket matching the clamp value
686 * which is pre-computed and stored to avoid expensive integer divisions from
687 * the fast path.
688 *
689 * The active bit is set whenever a task has got an "effective" value assigned,
690 * which can be different from the clamp value "requested" from user-space.
691 * This allows to know a task is refcounted in the rq's bucket corresponding
692 * to the "effective" bucket_id.
693 *
694 * The user_defined bit is set whenever a task has got a task-specific clamp
695 * value requested from userspace, i.e. the system defaults apply to this task
696 * just as a restriction. This allows to relax default clamps when a less
697 * restrictive task-specific value has been requested, thus allowing to
698 * implement a "nice" semantic. For example, a task running with a 20%
699 * default boost can still drop its own boosting to 0%.
700 */
701 struct uclamp_se {
702 unsigned int value : bits_per(SCHED_CAPACITY_SCALE);
703 unsigned int bucket_id : bits_per(UCLAMP_BUCKETS);
704 unsigned int active : 1;
705 unsigned int user_defined : 1;
706 };
707 #endif /* CONFIG_UCLAMP_TASK */
708
709 union rcu_special {
710 struct {
711 u8 blocked;
712 u8 need_qs;
713 u8 exp_hint; /* Hint for performance. */
714 u8 need_mb; /* Readers need smp_mb(). */
715 } b; /* Bits. */
716 u32 s; /* Set of bits. */
717 };
718
719 enum perf_event_task_context {
720 perf_invalid_context = -1,
721 perf_hw_context = 0,
722 perf_sw_context,
723 perf_nr_task_contexts,
724 };
725
726 struct wake_q_node {
727 struct wake_q_node *next;
728 };
729
730 struct kmap_ctrl {
731 #ifdef CONFIG_KMAP_LOCAL
732 int idx;
733 pte_t pteval[KM_MAX_IDX];
734 #endif
735 };
736
737 struct task_struct {
738 #ifdef CONFIG_THREAD_INFO_IN_TASK
739 /*
740 * For reasons of header soup (see current_thread_info()), this
741 * must be the first element of task_struct.
742 */
743 struct thread_info thread_info;
744 #endif
745 unsigned int __state;
746
747 #ifdef CONFIG_PREEMPT_RT
748 /* saved state for "spinlock sleepers" */
749 unsigned int saved_state;
750 #endif
751
752 /*
753 * This begins the randomizable portion of task_struct. Only
754 * scheduling-critical items should be added above here.
755 */
756 randomized_struct_fields_start
757
758 void *stack;
759 refcount_t usage;
760 /* Per task flags (PF_*), defined further below: */
761 unsigned int flags;
762 unsigned int ptrace;
763
764 #ifdef CONFIG_SMP
765 int on_cpu;
766 struct __call_single_node wake_entry;
767 unsigned int wakee_flips;
768 unsigned long wakee_flip_decay_ts;
769 struct task_struct *last_wakee;
770
771 /*
772 * recent_used_cpu is initially set as the last CPU used by a task
773 * that wakes affine another task. Waker/wakee relationships can
774 * push tasks around a CPU where each wakeup moves to the next one.
775 * Tracking a recently used CPU allows a quick search for a recently
776 * used CPU that may be idle.
777 */
778 int recent_used_cpu;
779 int wake_cpu;
780 #endif
781 int on_rq;
782
783 int prio;
784 int static_prio;
785 int normal_prio;
786 unsigned int rt_priority;
787
788 struct sched_entity se;
789 struct sched_rt_entity rt;
790 struct sched_dl_entity dl;
791 const struct sched_class *sched_class;
792
793 #ifdef CONFIG_SCHED_CORE
794 struct rb_node core_node;
795 unsigned long core_cookie;
796 unsigned int core_occupation;
797 #endif
798
799 #ifdef CONFIG_CGROUP_SCHED
800 struct task_group *sched_task_group;
801 #endif
802
803 #ifdef CONFIG_UCLAMP_TASK
804 /*
805 * Clamp values requested for a scheduling entity.
806 * Must be updated with task_rq_lock() held.
807 */
808 struct uclamp_se uclamp_req[UCLAMP_CNT];
809 /*
810 * Effective clamp values used for a scheduling entity.
811 * Must be updated with task_rq_lock() held.
812 */
813 struct uclamp_se uclamp[UCLAMP_CNT];
814 #endif
815
816 struct sched_statistics stats;
817
818 #ifdef CONFIG_PREEMPT_NOTIFIERS
819 /* List of struct preempt_notifier: */
820 struct hlist_head preempt_notifiers;
821 #endif
822
823 #ifdef CONFIG_BLK_DEV_IO_TRACE
824 unsigned int btrace_seq;
825 #endif
826
827 unsigned int policy;
828 int nr_cpus_allowed;
829 const cpumask_t *cpus_ptr;
830 cpumask_t *user_cpus_ptr;
831 cpumask_t cpus_mask;
832 void *migration_pending;
833 #ifdef CONFIG_SMP
834 unsigned short migration_disabled;
835 #endif
836 unsigned short migration_flags;
837
838 #ifdef CONFIG_PREEMPT_RCU
839 int rcu_read_lock_nesting;
840 union rcu_special rcu_read_unlock_special;
841 struct list_head rcu_node_entry;
842 struct rcu_node *rcu_blocked_node;
843 #endif /* #ifdef CONFIG_PREEMPT_RCU */
844
845 #ifdef CONFIG_TASKS_RCU
846 unsigned long rcu_tasks_nvcsw;
847 u8 rcu_tasks_holdout;
848 u8 rcu_tasks_idx;
849 int rcu_tasks_idle_cpu;
850 struct list_head rcu_tasks_holdout_list;
851 #endif /* #ifdef CONFIG_TASKS_RCU */
852
853 #ifdef CONFIG_TASKS_TRACE_RCU
854 int trc_reader_nesting;
855 int trc_ipi_to_cpu;
856 union rcu_special trc_reader_special;
857 struct list_head trc_holdout_list;
858 struct list_head trc_blkd_node;
859 int trc_blkd_cpu;
860 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
861
862 struct sched_info sched_info;
863
864 struct list_head tasks;
865 #ifdef CONFIG_SMP
866 struct plist_node pushable_tasks;
867 struct rb_node pushable_dl_tasks;
868 #endif
869
870 struct mm_struct *mm;
871 struct mm_struct *active_mm;
872
873 #ifdef SPLIT_RSS_COUNTING
874 struct task_rss_stat rss_stat;
875 #endif
876 int exit_state;
877 int exit_code;
878 int exit_signal;
879 /* The signal sent when the parent dies: */
880 int pdeath_signal;
881 /* JOBCTL_*, siglock protected: */
882 unsigned long jobctl;
883
884 /* Used for emulating ABI behavior of previous Linux versions: */
885 unsigned int personality;
886
887 /* Scheduler bits, serialized by scheduler locks: */
888 unsigned sched_reset_on_fork:1;
889 unsigned sched_contributes_to_load:1;
890 unsigned sched_migrated:1;
891 #ifdef CONFIG_PSI
892 unsigned sched_psi_wake_requeue:1;
893 #endif
894
895 /* Force alignment to the next boundary: */
896 unsigned :0;
897
898 /* Unserialized, strictly 'current' */
899
900 /*
901 * This field must not be in the scheduler word above due to wakelist
902 * queueing no longer being serialized by p->on_cpu. However:
903 *
904 * p->XXX = X; ttwu()
905 * schedule() if (p->on_rq && ..) // false
906 * smp_mb__after_spinlock(); if (smp_load_acquire(&p->on_cpu) && //true
907 * deactivate_task() ttwu_queue_wakelist())
908 * p->on_rq = 0; p->sched_remote_wakeup = Y;
909 *
910 * guarantees all stores of 'current' are visible before
911 * ->sched_remote_wakeup gets used, so it can be in this word.
912 */
913 unsigned sched_remote_wakeup:1;
914
915 /* Bit to tell LSMs we're in execve(): */
916 unsigned in_execve:1;
917 unsigned in_iowait:1;
918 #ifndef TIF_RESTORE_SIGMASK
919 unsigned restore_sigmask:1;
920 #endif
921 #ifdef CONFIG_MEMCG
922 unsigned in_user_fault:1;
923 #endif
924 #ifdef CONFIG_LRU_GEN
925 /* whether the LRU algorithm may apply to this access */
926 unsigned in_lru_fault:1;
927 #endif
928 #ifdef CONFIG_COMPAT_BRK
929 unsigned brk_randomized:1;
930 #endif
931 #ifdef CONFIG_CGROUPS
932 /* disallow userland-initiated cgroup migration */
933 unsigned no_cgroup_migration:1;
934 /* task is frozen/stopped (used by the cgroup freezer) */
935 unsigned frozen:1;
936 #endif
937 #ifdef CONFIG_BLK_CGROUP
938 unsigned use_memdelay:1;
939 #endif
940 #ifdef CONFIG_PSI
941 /* Stalled due to lack of memory */
942 unsigned in_memstall:1;
943 #endif
944 #ifdef CONFIG_PAGE_OWNER
945 /* Used by page_owner=on to detect recursion in page tracking. */
946 unsigned in_page_owner:1;
947 #endif
948 #ifdef CONFIG_EVENTFD
949 /* Recursion prevention for eventfd_signal() */
950 unsigned in_eventfd:1;
951 #endif
952 #ifdef CONFIG_IOMMU_SVA
953 unsigned pasid_activated:1;
954 #endif
955 #ifdef CONFIG_CPU_SUP_INTEL
956 unsigned reported_split_lock:1;
957 #endif
958 #ifdef CONFIG_TASK_DELAY_ACCT
959 /* delay due to memory thrashing */
960 unsigned in_thrashing:1;
961 #endif
962
963 unsigned long atomic_flags; /* Flags requiring atomic access. */
964
965 struct restart_block restart_block;
966
967 pid_t pid;
968 pid_t tgid;
969
970 #ifdef CONFIG_STACKPROTECTOR
971 /* Canary value for the -fstack-protector GCC feature: */
972 unsigned long stack_canary;
973 #endif
974 /*
975 * Pointers to the (original) parent process, youngest child, younger sibling,
976 * older sibling, respectively. (p->father can be replaced with
977 * p->real_parent->pid)
978 */
979
980 /* Real parent process: */
981 struct task_struct __rcu *real_parent;
982
983 /* Recipient of SIGCHLD, wait4() reports: */
984 struct task_struct __rcu *parent;
985
986 /*
987 * Children/sibling form the list of natural children:
988 */
989 struct list_head children;
990 struct list_head sibling;
991 struct task_struct *group_leader;
992
993 /*
994 * 'ptraced' is the list of tasks this task is using ptrace() on.
995 *
996 * This includes both natural children and PTRACE_ATTACH targets.
997 * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
998 */
999 struct list_head ptraced;
1000 struct list_head ptrace_entry;
1001
1002 /* PID/PID hash table linkage. */
1003 struct pid *thread_pid;
1004 struct hlist_node pid_links[PIDTYPE_MAX];
1005 struct list_head thread_group;
1006 struct list_head thread_node;
1007
1008 struct completion *vfork_done;
1009
1010 /* CLONE_CHILD_SETTID: */
1011 int __user *set_child_tid;
1012
1013 /* CLONE_CHILD_CLEARTID: */
1014 int __user *clear_child_tid;
1015
1016 /* PF_KTHREAD | PF_IO_WORKER */
1017 void *worker_private;
1018
1019 u64 utime;
1020 u64 stime;
1021 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
1022 u64 utimescaled;
1023 u64 stimescaled;
1024 #endif
1025 u64 gtime;
1026 struct prev_cputime prev_cputime;
1027 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1028 struct vtime vtime;
1029 #endif
1030
1031 #ifdef CONFIG_NO_HZ_FULL
1032 atomic_t tick_dep_mask;
1033 #endif
1034 /* Context switch counts: */
1035 unsigned long nvcsw;
1036 unsigned long nivcsw;
1037
1038 /* Monotonic time in nsecs: */
1039 u64 start_time;
1040
1041 /* Boot based time in nsecs: */
1042 u64 start_boottime;
1043
1044 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
1045 unsigned long min_flt;
1046 unsigned long maj_flt;
1047
1048 /* Empty if CONFIG_POSIX_CPUTIMERS=n */
1049 struct posix_cputimers posix_cputimers;
1050
1051 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK
1052 struct posix_cputimers_work posix_cputimers_work;
1053 #endif
1054
1055 /* Process credentials: */
1056
1057 /* Tracer's credentials at attach: */
1058 const struct cred __rcu *ptracer_cred;
1059
1060 /* Objective and real subjective task credentials (COW): */
1061 const struct cred __rcu *real_cred;
1062
1063 /* Effective (overridable) subjective task credentials (COW): */
1064 const struct cred __rcu *cred;
1065
1066 #ifdef CONFIG_KEYS
1067 /* Cached requested key. */
1068 struct key *cached_requested_key;
1069 #endif
1070
1071 /*
1072 * executable name, excluding path.
1073 *
1074 * - normally initialized setup_new_exec()
1075 * - access it with [gs]et_task_comm()
1076 * - lock it with task_lock()
1077 */
1078 char comm[TASK_COMM_LEN];
1079
1080 struct nameidata *nameidata;
1081
1082 #ifdef CONFIG_SYSVIPC
1083 struct sysv_sem sysvsem;
1084 struct sysv_shm sysvshm;
1085 #endif
1086 #ifdef CONFIG_DETECT_HUNG_TASK
1087 unsigned long last_switch_count;
1088 unsigned long last_switch_time;
1089 #endif
1090 /* Filesystem information: */
1091 struct fs_struct *fs;
1092
1093 /* Open file information: */
1094 struct files_struct *files;
1095
1096 #ifdef CONFIG_IO_URING
1097 struct io_uring_task *io_uring;
1098 #endif
1099
1100 /* Namespaces: */
1101 struct nsproxy *nsproxy;
1102
1103 /* Signal handlers: */
1104 struct signal_struct *signal;
1105 struct sighand_struct __rcu *sighand;
1106 sigset_t blocked;
1107 sigset_t real_blocked;
1108 /* Restored if set_restore_sigmask() was used: */
1109 sigset_t saved_sigmask;
1110 struct sigpending pending;
1111 unsigned long sas_ss_sp;
1112 size_t sas_ss_size;
1113 unsigned int sas_ss_flags;
1114
1115 struct callback_head *task_works;
1116
1117 #ifdef CONFIG_AUDIT
1118 #ifdef CONFIG_AUDITSYSCALL
1119 struct audit_context *audit_context;
1120 #endif
1121 kuid_t loginuid;
1122 unsigned int sessionid;
1123 #endif
1124 struct seccomp seccomp;
1125 struct syscall_user_dispatch syscall_dispatch;
1126
1127 /* Thread group tracking: */
1128 u64 parent_exec_id;
1129 u64 self_exec_id;
1130
1131 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
1132 spinlock_t alloc_lock;
1133
1134 /* Protection of the PI data structures: */
1135 raw_spinlock_t pi_lock;
1136
1137 struct wake_q_node wake_q;
1138
1139 #ifdef CONFIG_RT_MUTEXES
1140 /* PI waiters blocked on a rt_mutex held by this task: */
1141 struct rb_root_cached pi_waiters;
1142 /* Updated under owner's pi_lock and rq lock */
1143 struct task_struct *pi_top_task;
1144 /* Deadlock detection and priority inheritance handling: */
1145 struct rt_mutex_waiter *pi_blocked_on;
1146 #endif
1147
1148 #ifdef CONFIG_DEBUG_MUTEXES
1149 /* Mutex deadlock detection: */
1150 struct mutex_waiter *blocked_on;
1151 #endif
1152
1153 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1154 int non_block_count;
1155 #endif
1156
1157 #ifdef CONFIG_TRACE_IRQFLAGS
1158 struct irqtrace_events irqtrace;
1159 unsigned int hardirq_threaded;
1160 u64 hardirq_chain_key;
1161 int softirqs_enabled;
1162 int softirq_context;
1163 int irq_config;
1164 #endif
1165 #ifdef CONFIG_PREEMPT_RT
1166 int softirq_disable_cnt;
1167 #endif
1168
1169 #ifdef CONFIG_LOCKDEP
1170 # define MAX_LOCK_DEPTH 48UL
1171 u64 curr_chain_key;
1172 int lockdep_depth;
1173 unsigned int lockdep_recursion;
1174 struct held_lock held_locks[MAX_LOCK_DEPTH];
1175 #endif
1176
1177 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP)
1178 unsigned int in_ubsan;
1179 #endif
1180
1181 /* Journalling filesystem info: */
1182 void *journal_info;
1183
1184 /* Stacked block device info: */
1185 struct bio_list *bio_list;
1186
1187 /* Stack plugging: */
1188 struct blk_plug *plug;
1189
1190 /* VM state: */
1191 struct reclaim_state *reclaim_state;
1192
1193 struct backing_dev_info *backing_dev_info;
1194
1195 struct io_context *io_context;
1196
1197 #ifdef CONFIG_COMPACTION
1198 struct capture_control *capture_control;
1199 #endif
1200 /* Ptrace state: */
1201 unsigned long ptrace_message;
1202 kernel_siginfo_t *last_siginfo;
1203
1204 struct task_io_accounting ioac;
1205 #ifdef CONFIG_PSI
1206 /* Pressure stall state */
1207 unsigned int psi_flags;
1208 #endif
1209 #ifdef CONFIG_TASK_XACCT
1210 /* Accumulated RSS usage: */
1211 u64 acct_rss_mem1;
1212 /* Accumulated virtual memory usage: */
1213 u64 acct_vm_mem1;
1214 /* stime + utime since last update: */
1215 u64 acct_timexpd;
1216 #endif
1217 #ifdef CONFIG_CPUSETS
1218 /* Protected by ->alloc_lock: */
1219 nodemask_t mems_allowed;
1220 /* Sequence number to catch updates: */
1221 seqcount_spinlock_t mems_allowed_seq;
1222 int cpuset_mem_spread_rotor;
1223 int cpuset_slab_spread_rotor;
1224 #endif
1225 #ifdef CONFIG_CGROUPS
1226 /* Control Group info protected by css_set_lock: */
1227 struct css_set __rcu *cgroups;
1228 /* cg_list protected by css_set_lock and tsk->alloc_lock: */
1229 struct list_head cg_list;
1230 #endif
1231 #ifdef CONFIG_X86_CPU_RESCTRL
1232 u32 closid;
1233 u32 rmid;
1234 #endif
1235 #ifdef CONFIG_FUTEX
1236 struct robust_list_head __user *robust_list;
1237 #ifdef CONFIG_COMPAT
1238 struct compat_robust_list_head __user *compat_robust_list;
1239 #endif
1240 struct list_head pi_state_list;
1241 struct futex_pi_state *pi_state_cache;
1242 struct mutex futex_exit_mutex;
1243 unsigned int futex_state;
1244 #endif
1245 #ifdef CONFIG_PERF_EVENTS
1246 struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1247 struct mutex perf_event_mutex;
1248 struct list_head perf_event_list;
1249 #endif
1250 #ifdef CONFIG_DEBUG_PREEMPT
1251 unsigned long preempt_disable_ip;
1252 #endif
1253 #ifdef CONFIG_NUMA
1254 /* Protected by alloc_lock: */
1255 struct mempolicy *mempolicy;
1256 short il_prev;
1257 short pref_node_fork;
1258 #endif
1259 #ifdef CONFIG_NUMA_BALANCING
1260 int numa_scan_seq;
1261 unsigned int numa_scan_period;
1262 unsigned int numa_scan_period_max;
1263 int numa_preferred_nid;
1264 unsigned long numa_migrate_retry;
1265 /* Migration stamp: */
1266 u64 node_stamp;
1267 u64 last_task_numa_placement;
1268 u64 last_sum_exec_runtime;
1269 struct callback_head numa_work;
1270
1271 /*
1272 * This pointer is only modified for current in syscall and
1273 * pagefault context (and for tasks being destroyed), so it can be read
1274 * from any of the following contexts:
1275 * - RCU read-side critical section
1276 * - current->numa_group from everywhere
1277 * - task's runqueue locked, task not running
1278 */
1279 struct numa_group __rcu *numa_group;
1280
1281 /*
1282 * numa_faults is an array split into four regions:
1283 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1284 * in this precise order.
1285 *
1286 * faults_memory: Exponential decaying average of faults on a per-node
1287 * basis. Scheduling placement decisions are made based on these
1288 * counts. The values remain static for the duration of a PTE scan.
1289 * faults_cpu: Track the nodes the process was running on when a NUMA
1290 * hinting fault was incurred.
1291 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1292 * during the current scan window. When the scan completes, the counts
1293 * in faults_memory and faults_cpu decay and these values are copied.
1294 */
1295 unsigned long *numa_faults;
1296 unsigned long total_numa_faults;
1297
1298 /*
1299 * numa_faults_locality tracks if faults recorded during the last
1300 * scan window were remote/local or failed to migrate. The task scan
1301 * period is adapted based on the locality of the faults with different
1302 * weights depending on whether they were shared or private faults
1303 */
1304 unsigned long numa_faults_locality[3];
1305
1306 unsigned long numa_pages_migrated;
1307 #endif /* CONFIG_NUMA_BALANCING */
1308
1309 #ifdef CONFIG_RSEQ
1310 struct rseq __user *rseq;
1311 u32 rseq_sig;
1312 /*
1313 * RmW on rseq_event_mask must be performed atomically
1314 * with respect to preemption.
1315 */
1316 unsigned long rseq_event_mask;
1317 #endif
1318
1319 struct tlbflush_unmap_batch tlb_ubc;
1320
1321 union {
1322 refcount_t rcu_users;
1323 struct rcu_head rcu;
1324 };
1325
1326 /* Cache last used pipe for splice(): */
1327 struct pipe_inode_info *splice_pipe;
1328
1329 struct page_frag task_frag;
1330
1331 #ifdef CONFIG_TASK_DELAY_ACCT
1332 struct task_delay_info *delays;
1333 #endif
1334
1335 #ifdef CONFIG_FAULT_INJECTION
1336 int make_it_fail;
1337 unsigned int fail_nth;
1338 #endif
1339 /*
1340 * When (nr_dirtied >= nr_dirtied_pause), it's time to call
1341 * balance_dirty_pages() for a dirty throttling pause:
1342 */
1343 int nr_dirtied;
1344 int nr_dirtied_pause;
1345 /* Start of a write-and-pause period: */
1346 unsigned long dirty_paused_when;
1347
1348 #ifdef CONFIG_LATENCYTOP
1349 int latency_record_count;
1350 struct latency_record latency_record[LT_SAVECOUNT];
1351 #endif
1352 /*
1353 * Time slack values; these are used to round up poll() and
1354 * select() etc timeout values. These are in nanoseconds.
1355 */
1356 u64 timer_slack_ns;
1357 u64 default_timer_slack_ns;
1358
1359 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
1360 unsigned int kasan_depth;
1361 #endif
1362
1363 #ifdef CONFIG_KCSAN
1364 struct kcsan_ctx kcsan_ctx;
1365 #ifdef CONFIG_TRACE_IRQFLAGS
1366 struct irqtrace_events kcsan_save_irqtrace;
1367 #endif
1368 #ifdef CONFIG_KCSAN_WEAK_MEMORY
1369 int kcsan_stack_depth;
1370 #endif
1371 #endif
1372
1373 #ifdef CONFIG_KMSAN
1374 struct kmsan_ctx kmsan_ctx;
1375 #endif
1376
1377 #if IS_ENABLED(CONFIG_KUNIT)
1378 struct kunit *kunit_test;
1379 #endif
1380
1381 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1382 /* Index of current stored address in ret_stack: */
1383 int curr_ret_stack;
1384 int curr_ret_depth;
1385
1386 /* Stack of return addresses for return function tracing: */
1387 struct ftrace_ret_stack *ret_stack;
1388
1389 /* Timestamp for last schedule: */
1390 unsigned long long ftrace_timestamp;
1391
1392 /*
1393 * Number of functions that haven't been traced
1394 * because of depth overrun:
1395 */
1396 atomic_t trace_overrun;
1397
1398 /* Pause tracing: */
1399 atomic_t tracing_graph_pause;
1400 #endif
1401
1402 #ifdef CONFIG_TRACING
1403 /* Bitmask and counter of trace recursion: */
1404 unsigned long trace_recursion;
1405 #endif /* CONFIG_TRACING */
1406
1407 #ifdef CONFIG_KCOV
1408 /* See kernel/kcov.c for more details. */
1409
1410 /* Coverage collection mode enabled for this task (0 if disabled): */
1411 unsigned int kcov_mode;
1412
1413 /* Size of the kcov_area: */
1414 unsigned int kcov_size;
1415
1416 /* Buffer for coverage collection: */
1417 void *kcov_area;
1418
1419 /* KCOV descriptor wired with this task or NULL: */
1420 struct kcov *kcov;
1421
1422 /* KCOV common handle for remote coverage collection: */
1423 u64 kcov_handle;
1424
1425 /* KCOV sequence number: */
1426 int kcov_sequence;
1427
1428 /* Collect coverage from softirq context: */
1429 unsigned int kcov_softirq;
1430 #endif
1431
1432 #ifdef CONFIG_MEMCG
1433 struct mem_cgroup *memcg_in_oom;
1434 gfp_t memcg_oom_gfp_mask;
1435 int memcg_oom_order;
1436
1437 /* Number of pages to reclaim on returning to userland: */
1438 unsigned int memcg_nr_pages_over_high;
1439
1440 /* Used by memcontrol for targeted memcg charge: */
1441 struct mem_cgroup *active_memcg;
1442 #endif
1443
1444 #ifdef CONFIG_BLK_CGROUP
1445 struct request_queue *throttle_queue;
1446 #endif
1447
1448 #ifdef CONFIG_UPROBES
1449 struct uprobe_task *utask;
1450 #endif
1451 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1452 unsigned int sequential_io;
1453 unsigned int sequential_io_avg;
1454 #endif
1455 struct kmap_ctrl kmap_ctrl;
1456 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1457 unsigned long task_state_change;
1458 # ifdef CONFIG_PREEMPT_RT
1459 unsigned long saved_state_change;
1460 # endif
1461 #endif
1462 int pagefault_disabled;
1463 #ifdef CONFIG_MMU
1464 struct task_struct *oom_reaper_list;
1465 struct timer_list oom_reaper_timer;
1466 #endif
1467 #ifdef CONFIG_VMAP_STACK
1468 struct vm_struct *stack_vm_area;
1469 #endif
1470 #ifdef CONFIG_THREAD_INFO_IN_TASK
1471 /* A live task holds one reference: */
1472 refcount_t stack_refcount;
1473 #endif
1474 #ifdef CONFIG_LIVEPATCH
1475 int patch_state;
1476 #endif
1477 #ifdef CONFIG_SECURITY
1478 /* Used by LSM modules for access restriction: */
1479 void *security;
1480 #endif
1481 #ifdef CONFIG_BPF_SYSCALL
1482 /* Used by BPF task local storage */
1483 struct bpf_local_storage __rcu *bpf_storage;
1484 /* Used for BPF run context */
1485 struct bpf_run_ctx *bpf_ctx;
1486 #endif
1487
1488 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK
1489 unsigned long lowest_stack;
1490 unsigned long prev_lowest_stack;
1491 #endif
1492
1493 #ifdef CONFIG_X86_MCE
1494 void __user *mce_vaddr;
1495 __u64 mce_kflags;
1496 u64 mce_addr;
1497 __u64 mce_ripv : 1,
1498 mce_whole_page : 1,
1499 __mce_reserved : 62;
1500 struct callback_head mce_kill_me;
1501 int mce_count;
1502 #endif
1503
1504 #ifdef CONFIG_KRETPROBES
1505 struct llist_head kretprobe_instances;
1506 #endif
1507 #ifdef CONFIG_RETHOOK
1508 struct llist_head rethooks;
1509 #endif
1510
1511 #ifdef CONFIG_ARCH_HAS_PARANOID_L1D_FLUSH
1512 /*
1513 * If L1D flush is supported on mm context switch
1514 * then we use this callback head to queue kill work
1515 * to kill tasks that are not running on SMT disabled
1516 * cores
1517 */
1518 struct callback_head l1d_flush_kill;
1519 #endif
1520
1521 #ifdef CONFIG_RV
1522 /*
1523 * Per-task RV monitor. Nowadays fixed in RV_PER_TASK_MONITORS.
1524 * If we find justification for more monitors, we can think
1525 * about adding more or developing a dynamic method. So far,
1526 * none of these are justified.
1527 */
1528 union rv_task_monitor rv[RV_PER_TASK_MONITORS];
1529 #endif
1530
1531 /*
1532 * New fields for task_struct should be added above here, so that
1533 * they are included in the randomized portion of task_struct.
1534 */
1535 randomized_struct_fields_end
1536
1537 /* CPU-specific state of this task: */
1538 struct thread_struct thread;
1539
1540 /*
1541 * WARNING: on x86, 'thread_struct' contains a variable-sized
1542 * structure. It *MUST* be at the end of 'task_struct'.
1543 *
1544 * Do not put anything below here!
1545 */
1546 };
1547
task_pid(struct task_struct * task)1548 static inline struct pid *task_pid(struct task_struct *task)
1549 {
1550 return task->thread_pid;
1551 }
1552
1553 /*
1554 * the helpers to get the task's different pids as they are seen
1555 * from various namespaces
1556 *
1557 * task_xid_nr() : global id, i.e. the id seen from the init namespace;
1558 * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of
1559 * current.
1560 * task_xid_nr_ns() : id seen from the ns specified;
1561 *
1562 * see also pid_nr() etc in include/linux/pid.h
1563 */
1564 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns);
1565
task_pid_nr(struct task_struct * tsk)1566 static inline pid_t task_pid_nr(struct task_struct *tsk)
1567 {
1568 return tsk->pid;
1569 }
1570
task_pid_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1571 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1572 {
1573 return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1574 }
1575
task_pid_vnr(struct task_struct * tsk)1576 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1577 {
1578 return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1579 }
1580
1581
task_tgid_nr(struct task_struct * tsk)1582 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1583 {
1584 return tsk->tgid;
1585 }
1586
1587 /**
1588 * pid_alive - check that a task structure is not stale
1589 * @p: Task structure to be checked.
1590 *
1591 * Test if a process is not yet dead (at most zombie state)
1592 * If pid_alive fails, then pointers within the task structure
1593 * can be stale and must not be dereferenced.
1594 *
1595 * Return: 1 if the process is alive. 0 otherwise.
1596 */
pid_alive(const struct task_struct * p)1597 static inline int pid_alive(const struct task_struct *p)
1598 {
1599 return p->thread_pid != NULL;
1600 }
1601
task_pgrp_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1602 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1603 {
1604 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1605 }
1606
task_pgrp_vnr(struct task_struct * tsk)1607 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1608 {
1609 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1610 }
1611
1612
task_session_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1613 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1614 {
1615 return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1616 }
1617
task_session_vnr(struct task_struct * tsk)1618 static inline pid_t task_session_vnr(struct task_struct *tsk)
1619 {
1620 return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1621 }
1622
task_tgid_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1623 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1624 {
1625 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, ns);
1626 }
1627
task_tgid_vnr(struct task_struct * tsk)1628 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1629 {
1630 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, NULL);
1631 }
1632
task_ppid_nr_ns(const struct task_struct * tsk,struct pid_namespace * ns)1633 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1634 {
1635 pid_t pid = 0;
1636
1637 rcu_read_lock();
1638 if (pid_alive(tsk))
1639 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1640 rcu_read_unlock();
1641
1642 return pid;
1643 }
1644
task_ppid_nr(const struct task_struct * tsk)1645 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1646 {
1647 return task_ppid_nr_ns(tsk, &init_pid_ns);
1648 }
1649
1650 /* Obsolete, do not use: */
task_pgrp_nr(struct task_struct * tsk)1651 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1652 {
1653 return task_pgrp_nr_ns(tsk, &init_pid_ns);
1654 }
1655
1656 #define TASK_REPORT_IDLE (TASK_REPORT + 1)
1657 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1)
1658
__task_state_index(unsigned int tsk_state,unsigned int tsk_exit_state)1659 static inline unsigned int __task_state_index(unsigned int tsk_state,
1660 unsigned int tsk_exit_state)
1661 {
1662 unsigned int state = (tsk_state | tsk_exit_state) & TASK_REPORT;
1663
1664 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX);
1665
1666 if (tsk_state == TASK_IDLE)
1667 state = TASK_REPORT_IDLE;
1668
1669 /*
1670 * We're lying here, but rather than expose a completely new task state
1671 * to userspace, we can make this appear as if the task has gone through
1672 * a regular rt_mutex_lock() call.
1673 */
1674 if (tsk_state == TASK_RTLOCK_WAIT)
1675 state = TASK_UNINTERRUPTIBLE;
1676
1677 return fls(state);
1678 }
1679
task_state_index(struct task_struct * tsk)1680 static inline unsigned int task_state_index(struct task_struct *tsk)
1681 {
1682 return __task_state_index(READ_ONCE(tsk->__state), tsk->exit_state);
1683 }
1684
task_index_to_char(unsigned int state)1685 static inline char task_index_to_char(unsigned int state)
1686 {
1687 static const char state_char[] = "RSDTtXZPI";
1688
1689 BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1);
1690
1691 return state_char[state];
1692 }
1693
task_state_to_char(struct task_struct * tsk)1694 static inline char task_state_to_char(struct task_struct *tsk)
1695 {
1696 return task_index_to_char(task_state_index(tsk));
1697 }
1698
1699 /**
1700 * is_global_init - check if a task structure is init. Since init
1701 * is free to have sub-threads we need to check tgid.
1702 * @tsk: Task structure to be checked.
1703 *
1704 * Check if a task structure is the first user space task the kernel created.
1705 *
1706 * Return: 1 if the task structure is init. 0 otherwise.
1707 */
is_global_init(struct task_struct * tsk)1708 static inline int is_global_init(struct task_struct *tsk)
1709 {
1710 return task_tgid_nr(tsk) == 1;
1711 }
1712
1713 extern struct pid *cad_pid;
1714
1715 /*
1716 * Per process flags
1717 */
1718 #define PF_VCPU 0x00000001 /* I'm a virtual CPU */
1719 #define PF_IDLE 0x00000002 /* I am an IDLE thread */
1720 #define PF_EXITING 0x00000004 /* Getting shut down */
1721 #define PF_POSTCOREDUMP 0x00000008 /* Coredumps should ignore this task */
1722 #define PF_IO_WORKER 0x00000010 /* Task is an IO worker */
1723 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */
1724 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */
1725 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */
1726 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */
1727 #define PF_DUMPCORE 0x00000200 /* Dumped core */
1728 #define PF_SIGNALED 0x00000400 /* Killed by a signal */
1729 #define PF_MEMALLOC 0x00000800 /* Allocating memory */
1730 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */
1731 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */
1732 #define PF__HOLE__00004000 0x00004000
1733 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */
1734 #define PF__HOLE__00010000 0x00010000
1735 #define PF_KSWAPD 0x00020000 /* I am kswapd */
1736 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocation requests will inherit GFP_NOFS */
1737 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocation requests will inherit GFP_NOIO */
1738 #define PF_LOCAL_THROTTLE 0x00100000 /* Throttle writes only against the bdi I write to,
1739 * I am cleaning dirty pages from some other bdi. */
1740 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */
1741 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */
1742 #define PF__HOLE__00800000 0x00800000
1743 #define PF__HOLE__01000000 0x01000000
1744 #define PF__HOLE__02000000 0x02000000
1745 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */
1746 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */
1747 #define PF_MEMALLOC_PIN 0x10000000 /* Allocation context constrained to zones which allow long term pinning. */
1748 #define PF__HOLE__20000000 0x20000000
1749 #define PF__HOLE__40000000 0x40000000
1750 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */
1751
1752 /*
1753 * Only the _current_ task can read/write to tsk->flags, but other
1754 * tasks can access tsk->flags in readonly mode for example
1755 * with tsk_used_math (like during threaded core dumping).
1756 * There is however an exception to this rule during ptrace
1757 * or during fork: the ptracer task is allowed to write to the
1758 * child->flags of its traced child (same goes for fork, the parent
1759 * can write to the child->flags), because we're guaranteed the
1760 * child is not running and in turn not changing child->flags
1761 * at the same time the parent does it.
1762 */
1763 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1764 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1765 #define clear_used_math() clear_stopped_child_used_math(current)
1766 #define set_used_math() set_stopped_child_used_math(current)
1767
1768 #define conditional_stopped_child_used_math(condition, child) \
1769 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1770
1771 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current)
1772
1773 #define copy_to_stopped_child_used_math(child) \
1774 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1775
1776 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1777 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1778 #define used_math() tsk_used_math(current)
1779
is_percpu_thread(void)1780 static __always_inline bool is_percpu_thread(void)
1781 {
1782 #ifdef CONFIG_SMP
1783 return (current->flags & PF_NO_SETAFFINITY) &&
1784 (current->nr_cpus_allowed == 1);
1785 #else
1786 return true;
1787 #endif
1788 }
1789
1790 /* Per-process atomic flags. */
1791 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */
1792 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */
1793 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */
1794 #define PFA_SPEC_SSB_DISABLE 3 /* Speculative Store Bypass disabled */
1795 #define PFA_SPEC_SSB_FORCE_DISABLE 4 /* Speculative Store Bypass force disabled*/
1796 #define PFA_SPEC_IB_DISABLE 5 /* Indirect branch speculation restricted */
1797 #define PFA_SPEC_IB_FORCE_DISABLE 6 /* Indirect branch speculation permanently restricted */
1798 #define PFA_SPEC_SSB_NOEXEC 7 /* Speculative Store Bypass clear on execve() */
1799
1800 #define TASK_PFA_TEST(name, func) \
1801 static inline bool task_##func(struct task_struct *p) \
1802 { return test_bit(PFA_##name, &p->atomic_flags); }
1803
1804 #define TASK_PFA_SET(name, func) \
1805 static inline void task_set_##func(struct task_struct *p) \
1806 { set_bit(PFA_##name, &p->atomic_flags); }
1807
1808 #define TASK_PFA_CLEAR(name, func) \
1809 static inline void task_clear_##func(struct task_struct *p) \
1810 { clear_bit(PFA_##name, &p->atomic_flags); }
1811
TASK_PFA_TEST(NO_NEW_PRIVS,no_new_privs)1812 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
1813 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
1814
1815 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
1816 TASK_PFA_SET(SPREAD_PAGE, spread_page)
1817 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
1818
1819 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
1820 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
1821 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
1822
1823 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable)
1824 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable)
1825 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable)
1826
1827 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1828 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1829 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1830
1831 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1832 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1833
1834 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable)
1835 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable)
1836 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable)
1837
1838 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1839 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1840
1841 static inline void
1842 current_restore_flags(unsigned long orig_flags, unsigned long flags)
1843 {
1844 current->flags &= ~flags;
1845 current->flags |= orig_flags & flags;
1846 }
1847
1848 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
1849 extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_effective_cpus);
1850 #ifdef CONFIG_SMP
1851 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
1852 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
1853 extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node);
1854 extern void release_user_cpus_ptr(struct task_struct *p);
1855 extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask);
1856 extern void force_compatible_cpus_allowed_ptr(struct task_struct *p);
1857 extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p);
1858 #else
do_set_cpus_allowed(struct task_struct * p,const struct cpumask * new_mask)1859 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
1860 {
1861 }
set_cpus_allowed_ptr(struct task_struct * p,const struct cpumask * new_mask)1862 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
1863 {
1864 if (!cpumask_test_cpu(0, new_mask))
1865 return -EINVAL;
1866 return 0;
1867 }
dup_user_cpus_ptr(struct task_struct * dst,struct task_struct * src,int node)1868 static inline int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node)
1869 {
1870 if (src->user_cpus_ptr)
1871 return -EINVAL;
1872 return 0;
1873 }
release_user_cpus_ptr(struct task_struct * p)1874 static inline void release_user_cpus_ptr(struct task_struct *p)
1875 {
1876 WARN_ON(p->user_cpus_ptr);
1877 }
1878
dl_task_check_affinity(struct task_struct * p,const struct cpumask * mask)1879 static inline int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask)
1880 {
1881 return 0;
1882 }
1883 #endif
1884
1885 extern int yield_to(struct task_struct *p, bool preempt);
1886 extern void set_user_nice(struct task_struct *p, long nice);
1887 extern int task_prio(const struct task_struct *p);
1888
1889 /**
1890 * task_nice - return the nice value of a given task.
1891 * @p: the task in question.
1892 *
1893 * Return: The nice value [ -20 ... 0 ... 19 ].
1894 */
task_nice(const struct task_struct * p)1895 static inline int task_nice(const struct task_struct *p)
1896 {
1897 return PRIO_TO_NICE((p)->static_prio);
1898 }
1899
1900 extern int can_nice(const struct task_struct *p, const int nice);
1901 extern int task_curr(const struct task_struct *p);
1902 extern int idle_cpu(int cpu);
1903 extern int available_idle_cpu(int cpu);
1904 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *);
1905 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *);
1906 extern void sched_set_fifo(struct task_struct *p);
1907 extern void sched_set_fifo_low(struct task_struct *p);
1908 extern void sched_set_normal(struct task_struct *p, int nice);
1909 extern int sched_setattr(struct task_struct *, const struct sched_attr *);
1910 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *);
1911 extern struct task_struct *idle_task(int cpu);
1912
1913 /**
1914 * is_idle_task - is the specified task an idle task?
1915 * @p: the task in question.
1916 *
1917 * Return: 1 if @p is an idle task. 0 otherwise.
1918 */
is_idle_task(const struct task_struct * p)1919 static __always_inline bool is_idle_task(const struct task_struct *p)
1920 {
1921 return !!(p->flags & PF_IDLE);
1922 }
1923
1924 extern struct task_struct *curr_task(int cpu);
1925 extern void ia64_set_curr_task(int cpu, struct task_struct *p);
1926
1927 void yield(void);
1928
1929 union thread_union {
1930 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK
1931 struct task_struct task;
1932 #endif
1933 #ifndef CONFIG_THREAD_INFO_IN_TASK
1934 struct thread_info thread_info;
1935 #endif
1936 unsigned long stack[THREAD_SIZE/sizeof(long)];
1937 };
1938
1939 #ifndef CONFIG_THREAD_INFO_IN_TASK
1940 extern struct thread_info init_thread_info;
1941 #endif
1942
1943 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
1944
1945 #ifdef CONFIG_THREAD_INFO_IN_TASK
1946 # define task_thread_info(task) (&(task)->thread_info)
1947 #elif !defined(__HAVE_THREAD_FUNCTIONS)
1948 # define task_thread_info(task) ((struct thread_info *)(task)->stack)
1949 #endif
1950
1951 /*
1952 * find a task by one of its numerical ids
1953 *
1954 * find_task_by_pid_ns():
1955 * finds a task by its pid in the specified namespace
1956 * find_task_by_vpid():
1957 * finds a task by its virtual pid
1958 *
1959 * see also find_vpid() etc in include/linux/pid.h
1960 */
1961
1962 extern struct task_struct *find_task_by_vpid(pid_t nr);
1963 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns);
1964
1965 /*
1966 * find a task by its virtual pid and get the task struct
1967 */
1968 extern struct task_struct *find_get_task_by_vpid(pid_t nr);
1969
1970 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
1971 extern int wake_up_process(struct task_struct *tsk);
1972 extern void wake_up_new_task(struct task_struct *tsk);
1973
1974 #ifdef CONFIG_SMP
1975 extern void kick_process(struct task_struct *tsk);
1976 #else
kick_process(struct task_struct * tsk)1977 static inline void kick_process(struct task_struct *tsk) { }
1978 #endif
1979
1980 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
1981
set_task_comm(struct task_struct * tsk,const char * from)1982 static inline void set_task_comm(struct task_struct *tsk, const char *from)
1983 {
1984 __set_task_comm(tsk, from, false);
1985 }
1986
1987 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk);
1988 #define get_task_comm(buf, tsk) ({ \
1989 BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN); \
1990 __get_task_comm(buf, sizeof(buf), tsk); \
1991 })
1992
1993 #ifdef CONFIG_SMP
scheduler_ipi(void)1994 static __always_inline void scheduler_ipi(void)
1995 {
1996 /*
1997 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting
1998 * TIF_NEED_RESCHED remotely (for the first time) will also send
1999 * this IPI.
2000 */
2001 preempt_fold_need_resched();
2002 }
2003 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state);
2004 #else
scheduler_ipi(void)2005 static inline void scheduler_ipi(void) { }
wait_task_inactive(struct task_struct * p,unsigned int match_state)2006 static inline unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state)
2007 {
2008 return 1;
2009 }
2010 #endif
2011
2012 /*
2013 * Set thread flags in other task's structures.
2014 * See asm/thread_info.h for TIF_xxxx flags available:
2015 */
set_tsk_thread_flag(struct task_struct * tsk,int flag)2016 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2017 {
2018 set_ti_thread_flag(task_thread_info(tsk), flag);
2019 }
2020
clear_tsk_thread_flag(struct task_struct * tsk,int flag)2021 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2022 {
2023 clear_ti_thread_flag(task_thread_info(tsk), flag);
2024 }
2025
update_tsk_thread_flag(struct task_struct * tsk,int flag,bool value)2026 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag,
2027 bool value)
2028 {
2029 update_ti_thread_flag(task_thread_info(tsk), flag, value);
2030 }
2031
test_and_set_tsk_thread_flag(struct task_struct * tsk,int flag)2032 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2033 {
2034 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2035 }
2036
test_and_clear_tsk_thread_flag(struct task_struct * tsk,int flag)2037 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2038 {
2039 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2040 }
2041
test_tsk_thread_flag(struct task_struct * tsk,int flag)2042 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2043 {
2044 return test_ti_thread_flag(task_thread_info(tsk), flag);
2045 }
2046
set_tsk_need_resched(struct task_struct * tsk)2047 static inline void set_tsk_need_resched(struct task_struct *tsk)
2048 {
2049 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2050 }
2051
clear_tsk_need_resched(struct task_struct * tsk)2052 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2053 {
2054 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2055 }
2056
test_tsk_need_resched(struct task_struct * tsk)2057 static inline int test_tsk_need_resched(struct task_struct *tsk)
2058 {
2059 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2060 }
2061
2062 /*
2063 * cond_resched() and cond_resched_lock(): latency reduction via
2064 * explicit rescheduling in places that are safe. The return
2065 * value indicates whether a reschedule was done in fact.
2066 * cond_resched_lock() will drop the spinlock before scheduling,
2067 */
2068 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC)
2069 extern int __cond_resched(void);
2070
2071 #if defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL)
2072
2073 DECLARE_STATIC_CALL(cond_resched, __cond_resched);
2074
_cond_resched(void)2075 static __always_inline int _cond_resched(void)
2076 {
2077 return static_call_mod(cond_resched)();
2078 }
2079
2080 #elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY)
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
2089
_cond_resched(void)2090 static inline int _cond_resched(void)
2091 {
2092 return __cond_resched();
2093 }
2094
2095 #endif /* CONFIG_PREEMPT_DYNAMIC */
2096
2097 #else
2098
_cond_resched(void)2099 static inline int _cond_resched(void) { return 0; }
2100
2101 #endif /* !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) */
2102
2103 #define cond_resched() ({ \
2104 __might_resched(__FILE__, __LINE__, 0); \
2105 _cond_resched(); \
2106 })
2107
2108 extern int __cond_resched_lock(spinlock_t *lock);
2109 extern int __cond_resched_rwlock_read(rwlock_t *lock);
2110 extern int __cond_resched_rwlock_write(rwlock_t *lock);
2111
2112 #define MIGHT_RESCHED_RCU_SHIFT 8
2113 #define MIGHT_RESCHED_PREEMPT_MASK ((1U << MIGHT_RESCHED_RCU_SHIFT) - 1)
2114
2115 #ifndef CONFIG_PREEMPT_RT
2116 /*
2117 * Non RT kernels have an elevated preempt count due to the held lock,
2118 * but are not allowed to be inside a RCU read side critical section
2119 */
2120 # define PREEMPT_LOCK_RESCHED_OFFSETS PREEMPT_LOCK_OFFSET
2121 #else
2122 /*
2123 * spin/rw_lock() on RT implies rcu_read_lock(). The might_sleep() check in
2124 * cond_resched*lock() has to take that into account because it checks for
2125 * preempt_count() and rcu_preempt_depth().
2126 */
2127 # define PREEMPT_LOCK_RESCHED_OFFSETS \
2128 (PREEMPT_LOCK_OFFSET + (1U << MIGHT_RESCHED_RCU_SHIFT))
2129 #endif
2130
2131 #define cond_resched_lock(lock) ({ \
2132 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \
2133 __cond_resched_lock(lock); \
2134 })
2135
2136 #define cond_resched_rwlock_read(lock) ({ \
2137 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \
2138 __cond_resched_rwlock_read(lock); \
2139 })
2140
2141 #define cond_resched_rwlock_write(lock) ({ \
2142 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \
2143 __cond_resched_rwlock_write(lock); \
2144 })
2145
cond_resched_rcu(void)2146 static inline void cond_resched_rcu(void)
2147 {
2148 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
2149 rcu_read_unlock();
2150 cond_resched();
2151 rcu_read_lock();
2152 #endif
2153 }
2154
2155 #ifdef CONFIG_PREEMPT_DYNAMIC
2156
2157 extern bool preempt_model_none(void);
2158 extern bool preempt_model_voluntary(void);
2159 extern bool preempt_model_full(void);
2160
2161 #else
2162
preempt_model_none(void)2163 static inline bool preempt_model_none(void)
2164 {
2165 return IS_ENABLED(CONFIG_PREEMPT_NONE);
2166 }
preempt_model_voluntary(void)2167 static inline bool preempt_model_voluntary(void)
2168 {
2169 return IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY);
2170 }
preempt_model_full(void)2171 static inline bool preempt_model_full(void)
2172 {
2173 return IS_ENABLED(CONFIG_PREEMPT);
2174 }
2175
2176 #endif
2177
preempt_model_rt(void)2178 static inline bool preempt_model_rt(void)
2179 {
2180 return IS_ENABLED(CONFIG_PREEMPT_RT);
2181 }
2182
2183 /*
2184 * Does the preemption model allow non-cooperative preemption?
2185 *
2186 * For !CONFIG_PREEMPT_DYNAMIC kernels this is an exact match with
2187 * CONFIG_PREEMPTION; for CONFIG_PREEMPT_DYNAMIC this doesn't work as the
2188 * kernel is *built* with CONFIG_PREEMPTION=y but may run with e.g. the
2189 * PREEMPT_NONE model.
2190 */
preempt_model_preemptible(void)2191 static inline bool preempt_model_preemptible(void)
2192 {
2193 return preempt_model_full() || preempt_model_rt();
2194 }
2195
2196 /*
2197 * Does a critical section need to be broken due to another
2198 * task waiting?: (technically does not depend on CONFIG_PREEMPTION,
2199 * but a general need for low latency)
2200 */
spin_needbreak(spinlock_t * lock)2201 static inline int spin_needbreak(spinlock_t *lock)
2202 {
2203 #ifdef CONFIG_PREEMPTION
2204 return spin_is_contended(lock);
2205 #else
2206 return 0;
2207 #endif
2208 }
2209
2210 /*
2211 * Check if a rwlock is contended.
2212 * Returns non-zero if there is another task waiting on the rwlock.
2213 * Returns zero if the lock is not contended or the system / underlying
2214 * rwlock implementation does not support contention detection.
2215 * Technically does not depend on CONFIG_PREEMPTION, but a general need
2216 * for low latency.
2217 */
rwlock_needbreak(rwlock_t * lock)2218 static inline int rwlock_needbreak(rwlock_t *lock)
2219 {
2220 #ifdef CONFIG_PREEMPTION
2221 return rwlock_is_contended(lock);
2222 #else
2223 return 0;
2224 #endif
2225 }
2226
need_resched(void)2227 static __always_inline bool need_resched(void)
2228 {
2229 return unlikely(tif_need_resched());
2230 }
2231
2232 /*
2233 * Wrappers for p->thread_info->cpu access. No-op on UP.
2234 */
2235 #ifdef CONFIG_SMP
2236
task_cpu(const struct task_struct * p)2237 static inline unsigned int task_cpu(const struct task_struct *p)
2238 {
2239 return READ_ONCE(task_thread_info(p)->cpu);
2240 }
2241
2242 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2243
2244 #else
2245
task_cpu(const struct task_struct * p)2246 static inline unsigned int task_cpu(const struct task_struct *p)
2247 {
2248 return 0;
2249 }
2250
set_task_cpu(struct task_struct * p,unsigned int cpu)2251 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2252 {
2253 }
2254
2255 #endif /* CONFIG_SMP */
2256
2257 extern bool sched_task_on_rq(struct task_struct *p);
2258 extern unsigned long get_wchan(struct task_struct *p);
2259 extern struct task_struct *cpu_curr_snapshot(int cpu);
2260
2261 /*
2262 * In order to reduce various lock holder preemption latencies provide an
2263 * interface to see if a vCPU is currently running or not.
2264 *
2265 * This allows us to terminate optimistic spin loops and block, analogous to
2266 * the native optimistic spin heuristic of testing if the lock owner task is
2267 * running or not.
2268 */
2269 #ifndef vcpu_is_preempted
vcpu_is_preempted(int cpu)2270 static inline bool vcpu_is_preempted(int cpu)
2271 {
2272 return false;
2273 }
2274 #endif
2275
2276 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2277 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2278
2279 #ifndef TASK_SIZE_OF
2280 #define TASK_SIZE_OF(tsk) TASK_SIZE
2281 #endif
2282
2283 #ifdef CONFIG_SMP
owner_on_cpu(struct task_struct * owner)2284 static inline bool owner_on_cpu(struct task_struct *owner)
2285 {
2286 /*
2287 * As lock holder preemption issue, we both skip spinning if
2288 * task is not on cpu or its cpu is preempted
2289 */
2290 return READ_ONCE(owner->on_cpu) && !vcpu_is_preempted(task_cpu(owner));
2291 }
2292
2293 /* Returns effective CPU energy utilization, as seen by the scheduler */
2294 unsigned long sched_cpu_util(int cpu);
2295 #endif /* CONFIG_SMP */
2296
2297 #ifdef CONFIG_RSEQ
2298
2299 /*
2300 * Map the event mask on the user-space ABI enum rseq_cs_flags
2301 * for direct mask checks.
2302 */
2303 enum rseq_event_mask_bits {
2304 RSEQ_EVENT_PREEMPT_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT,
2305 RSEQ_EVENT_SIGNAL_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT,
2306 RSEQ_EVENT_MIGRATE_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT,
2307 };
2308
2309 enum rseq_event_mask {
2310 RSEQ_EVENT_PREEMPT = (1U << RSEQ_EVENT_PREEMPT_BIT),
2311 RSEQ_EVENT_SIGNAL = (1U << RSEQ_EVENT_SIGNAL_BIT),
2312 RSEQ_EVENT_MIGRATE = (1U << RSEQ_EVENT_MIGRATE_BIT),
2313 };
2314
rseq_set_notify_resume(struct task_struct * t)2315 static inline void rseq_set_notify_resume(struct task_struct *t)
2316 {
2317 if (t->rseq)
2318 set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
2319 }
2320
2321 void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs);
2322
rseq_handle_notify_resume(struct ksignal * ksig,struct pt_regs * regs)2323 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
2324 struct pt_regs *regs)
2325 {
2326 if (current->rseq)
2327 __rseq_handle_notify_resume(ksig, regs);
2328 }
2329
rseq_signal_deliver(struct ksignal * ksig,struct pt_regs * regs)2330 static inline void rseq_signal_deliver(struct ksignal *ksig,
2331 struct pt_regs *regs)
2332 {
2333 preempt_disable();
2334 __set_bit(RSEQ_EVENT_SIGNAL_BIT, ¤t->rseq_event_mask);
2335 preempt_enable();
2336 rseq_handle_notify_resume(ksig, regs);
2337 }
2338
2339 /* rseq_preempt() requires preemption to be disabled. */
rseq_preempt(struct task_struct * t)2340 static inline void rseq_preempt(struct task_struct *t)
2341 {
2342 __set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask);
2343 rseq_set_notify_resume(t);
2344 }
2345
2346 /* rseq_migrate() requires preemption to be disabled. */
rseq_migrate(struct task_struct * t)2347 static inline void rseq_migrate(struct task_struct *t)
2348 {
2349 __set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask);
2350 rseq_set_notify_resume(t);
2351 }
2352
2353 /*
2354 * If parent process has a registered restartable sequences area, the
2355 * child inherits. Unregister rseq for a clone with CLONE_VM set.
2356 */
rseq_fork(struct task_struct * t,unsigned long clone_flags)2357 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
2358 {
2359 if (clone_flags & CLONE_VM) {
2360 t->rseq = NULL;
2361 t->rseq_sig = 0;
2362 t->rseq_event_mask = 0;
2363 } else {
2364 t->rseq = current->rseq;
2365 t->rseq_sig = current->rseq_sig;
2366 t->rseq_event_mask = current->rseq_event_mask;
2367 }
2368 }
2369
rseq_execve(struct task_struct * t)2370 static inline void rseq_execve(struct task_struct *t)
2371 {
2372 t->rseq = NULL;
2373 t->rseq_sig = 0;
2374 t->rseq_event_mask = 0;
2375 }
2376
2377 #else
2378
rseq_set_notify_resume(struct task_struct * t)2379 static inline void rseq_set_notify_resume(struct task_struct *t)
2380 {
2381 }
rseq_handle_notify_resume(struct ksignal * ksig,struct pt_regs * regs)2382 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
2383 struct pt_regs *regs)
2384 {
2385 }
rseq_signal_deliver(struct ksignal * ksig,struct pt_regs * regs)2386 static inline void rseq_signal_deliver(struct ksignal *ksig,
2387 struct pt_regs *regs)
2388 {
2389 }
rseq_preempt(struct task_struct * t)2390 static inline void rseq_preempt(struct task_struct *t)
2391 {
2392 }
rseq_migrate(struct task_struct * t)2393 static inline void rseq_migrate(struct task_struct *t)
2394 {
2395 }
rseq_fork(struct task_struct * t,unsigned long clone_flags)2396 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
2397 {
2398 }
rseq_execve(struct task_struct * t)2399 static inline void rseq_execve(struct task_struct *t)
2400 {
2401 }
2402
2403 #endif
2404
2405 #ifdef CONFIG_DEBUG_RSEQ
2406
2407 void rseq_syscall(struct pt_regs *regs);
2408
2409 #else
2410
rseq_syscall(struct pt_regs * regs)2411 static inline void rseq_syscall(struct pt_regs *regs)
2412 {
2413 }
2414
2415 #endif
2416
2417 #ifdef CONFIG_SCHED_CORE
2418 extern void sched_core_free(struct task_struct *tsk);
2419 extern void sched_core_fork(struct task_struct *p);
2420 extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type,
2421 unsigned long uaddr);
2422 #else
sched_core_free(struct task_struct * tsk)2423 static inline void sched_core_free(struct task_struct *tsk) { }
sched_core_fork(struct task_struct * p)2424 static inline void sched_core_fork(struct task_struct *p) { }
2425 #endif
2426
2427 extern void sched_set_stop_task(int cpu, struct task_struct *stop);
2428
2429 #endif
2430