1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_SCHED_H
3 #define _LINUX_SCHED_H
4
5 /*
6 * Define 'struct task_struct' and provide the main scheduler
7 * APIs (schedule(), wakeup variants, etc.)
8 */
9
10 #include <uapi/linux/sched.h>
11
12 #include <asm/current.h>
13
14 #include <linux/pid.h>
15 #include <linux/sem.h>
16 #include <linux/shm.h>
17 #include <linux/kmsan_types.h>
18 #include <linux/mutex.h>
19 #include <linux/plist.h>
20 #include <linux/hrtimer.h>
21 #include <linux/irqflags.h>
22 #include <linux/seccomp.h>
23 #include <linux/nodemask.h>
24 #include <linux/rcupdate.h>
25 #include <linux/refcount.h>
26 #include <linux/resource.h>
27 #include <linux/latencytop.h>
28 #include <linux/sched/prio.h>
29 #include <linux/sched/types.h>
30 #include <linux/signal_types.h>
31 #include <linux/syscall_user_dispatch.h>
32 #include <linux/mm_types_task.h>
33 #include <linux/task_io_accounting.h>
34 #include <linux/posix-timers.h>
35 #include <linux/rseq.h>
36 #include <linux/seqlock.h>
37 #include <linux/kcsan.h>
38 #include <linux/rv.h>
39 #include <linux/livepatch_sched.h>
40 #include <asm/kmap_size.h>
41
42 /* task_struct member predeclarations (sorted alphabetically): */
43 struct audit_context;
44 struct bio_list;
45 struct blk_plug;
46 struct bpf_local_storage;
47 struct bpf_run_ctx;
48 struct capture_control;
49 struct cfs_rq;
50 struct fs_struct;
51 struct futex_pi_state;
52 struct io_context;
53 struct io_uring_task;
54 struct mempolicy;
55 struct nameidata;
56 struct nsproxy;
57 struct perf_event_context;
58 struct pid_namespace;
59 struct pipe_inode_info;
60 struct rcu_node;
61 struct reclaim_state;
62 struct robust_list_head;
63 struct root_domain;
64 struct rq;
65 struct sched_attr;
66 struct seq_file;
67 struct sighand_struct;
68 struct signal_struct;
69 struct task_delay_info;
70 struct task_group;
71 struct user_event_mm;
72
73 /*
74 * Task state bitmask. NOTE! These bits are also
75 * encoded in fs/proc/array.c: get_task_state().
76 *
77 * We have two separate sets of flags: task->__state
78 * is about runnability, while task->exit_state are
79 * about the task exiting. Confusing, but this way
80 * modifying one set can't modify the other one by
81 * mistake.
82 */
83
84 /* Used in tsk->__state: */
85 #define TASK_RUNNING 0x00000000
86 #define TASK_INTERRUPTIBLE 0x00000001
87 #define TASK_UNINTERRUPTIBLE 0x00000002
88 #define __TASK_STOPPED 0x00000004
89 #define __TASK_TRACED 0x00000008
90 /* Used in tsk->exit_state: */
91 #define EXIT_DEAD 0x00000010
92 #define EXIT_ZOMBIE 0x00000020
93 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD)
94 /* Used in tsk->__state again: */
95 #define TASK_PARKED 0x00000040
96 #define TASK_DEAD 0x00000080
97 #define TASK_WAKEKILL 0x00000100
98 #define TASK_WAKING 0x00000200
99 #define TASK_NOLOAD 0x00000400
100 #define TASK_NEW 0x00000800
101 #define TASK_RTLOCK_WAIT 0x00001000
102 #define TASK_FREEZABLE 0x00002000
103 #define __TASK_FREEZABLE_UNSAFE (0x00004000 * IS_ENABLED(CONFIG_LOCKDEP))
104 #define TASK_FROZEN 0x00008000
105 #define TASK_STATE_MAX 0x00010000
106
107 #define TASK_ANY (TASK_STATE_MAX-1)
108
109 /*
110 * DO NOT ADD ANY NEW USERS !
111 */
112 #define TASK_FREEZABLE_UNSAFE (TASK_FREEZABLE | __TASK_FREEZABLE_UNSAFE)
113
114 /* Convenience macros for the sake of set_current_state: */
115 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
116 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED)
117 #define TASK_TRACED __TASK_TRACED
118
119 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
120
121 /* Convenience macros for the sake of wake_up(): */
122 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
123
124 /* get_task_state(): */
125 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \
126 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
127 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
128 TASK_PARKED)
129
130 #define task_is_running(task) (READ_ONCE((task)->__state) == TASK_RUNNING)
131
132 #define task_is_traced(task) ((READ_ONCE(task->jobctl) & JOBCTL_TRACED) != 0)
133 #define task_is_stopped(task) ((READ_ONCE(task->jobctl) & JOBCTL_STOPPED) != 0)
134 #define task_is_stopped_or_traced(task) ((READ_ONCE(task->jobctl) & (JOBCTL_STOPPED | JOBCTL_TRACED)) != 0)
135
136 /*
137 * Special states are those that do not use the normal wait-loop pattern. See
138 * the comment with set_special_state().
139 */
140 #define is_special_task_state(state) \
141 ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD))
142
143 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
144 # define debug_normal_state_change(state_value) \
145 do { \
146 WARN_ON_ONCE(is_special_task_state(state_value)); \
147 current->task_state_change = _THIS_IP_; \
148 } while (0)
149
150 # define debug_special_state_change(state_value) \
151 do { \
152 WARN_ON_ONCE(!is_special_task_state(state_value)); \
153 current->task_state_change = _THIS_IP_; \
154 } while (0)
155
156 # define debug_rtlock_wait_set_state() \
157 do { \
158 current->saved_state_change = current->task_state_change;\
159 current->task_state_change = _THIS_IP_; \
160 } while (0)
161
162 # define debug_rtlock_wait_restore_state() \
163 do { \
164 current->task_state_change = current->saved_state_change;\
165 } while (0)
166
167 #else
168 # define debug_normal_state_change(cond) do { } while (0)
169 # define debug_special_state_change(cond) do { } while (0)
170 # define debug_rtlock_wait_set_state() do { } while (0)
171 # define debug_rtlock_wait_restore_state() do { } while (0)
172 #endif
173
174 /*
175 * set_current_state() includes a barrier so that the write of current->__state
176 * is correctly serialised wrt the caller's subsequent test of whether to
177 * actually sleep:
178 *
179 * for (;;) {
180 * set_current_state(TASK_UNINTERRUPTIBLE);
181 * if (CONDITION)
182 * break;
183 *
184 * schedule();
185 * }
186 * __set_current_state(TASK_RUNNING);
187 *
188 * If the caller does not need such serialisation (because, for instance, the
189 * CONDITION test and condition change and wakeup are under the same lock) then
190 * use __set_current_state().
191 *
192 * The above is typically ordered against the wakeup, which does:
193 *
194 * CONDITION = 1;
195 * wake_up_state(p, TASK_UNINTERRUPTIBLE);
196 *
197 * where wake_up_state()/try_to_wake_up() executes a full memory barrier before
198 * accessing p->__state.
199 *
200 * Wakeup will do: if (@state & p->__state) p->__state = TASK_RUNNING, that is,
201 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
202 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
203 *
204 * However, with slightly different timing the wakeup TASK_RUNNING store can
205 * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not
206 * a problem either because that will result in one extra go around the loop
207 * and our @cond test will save the day.
208 *
209 * Also see the comments of try_to_wake_up().
210 */
211 #define __set_current_state(state_value) \
212 do { \
213 debug_normal_state_change((state_value)); \
214 WRITE_ONCE(current->__state, (state_value)); \
215 } while (0)
216
217 #define set_current_state(state_value) \
218 do { \
219 debug_normal_state_change((state_value)); \
220 smp_store_mb(current->__state, (state_value)); \
221 } while (0)
222
223 /*
224 * set_special_state() should be used for those states when the blocking task
225 * can not use the regular condition based wait-loop. In that case we must
226 * serialize against wakeups such that any possible in-flight TASK_RUNNING
227 * stores will not collide with our state change.
228 */
229 #define set_special_state(state_value) \
230 do { \
231 unsigned long flags; /* may shadow */ \
232 \
233 raw_spin_lock_irqsave(¤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_param {
373 int sched_priority;
374 };
375
376 struct sched_info {
377 #ifdef CONFIG_SCHED_INFO
378 /* Cumulative counters: */
379
380 /* # of times we have run on this CPU: */
381 unsigned long pcount;
382
383 /* Time spent waiting on a runqueue: */
384 unsigned long long run_delay;
385
386 /* Timestamps: */
387
388 /* When did we last run on a CPU? */
389 unsigned long long last_arrival;
390
391 /* When were we last queued to run? */
392 unsigned long long last_queued;
393
394 #endif /* CONFIG_SCHED_INFO */
395 };
396
397 /*
398 * Integer metrics need fixed point arithmetic, e.g., sched/fair
399 * has a few: load, load_avg, util_avg, freq, and capacity.
400 *
401 * We define a basic fixed point arithmetic range, and then formalize
402 * all these metrics based on that basic range.
403 */
404 # define SCHED_FIXEDPOINT_SHIFT 10
405 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT)
406
407 /* Increase resolution of cpu_capacity calculations */
408 # define SCHED_CAPACITY_SHIFT SCHED_FIXEDPOINT_SHIFT
409 # define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT)
410
411 struct load_weight {
412 unsigned long weight;
413 u32 inv_weight;
414 };
415
416 /**
417 * struct util_est - Estimation utilization of FAIR tasks
418 * @enqueued: instantaneous estimated utilization of a task/cpu
419 * @ewma: the Exponential Weighted Moving Average (EWMA)
420 * utilization of a task
421 *
422 * Support data structure to track an Exponential Weighted Moving Average
423 * (EWMA) of a FAIR task's utilization. New samples are added to the moving
424 * average each time a task completes an activation. Sample's weight is chosen
425 * so that the EWMA will be relatively insensitive to transient changes to the
426 * task's workload.
427 *
428 * The enqueued attribute has a slightly different meaning for tasks and cpus:
429 * - task: the task's util_avg at last task dequeue time
430 * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU
431 * Thus, the util_est.enqueued of a task represents the contribution on the
432 * estimated utilization of the CPU where that task is currently enqueued.
433 *
434 * Only for tasks we track a moving average of the past instantaneous
435 * estimated utilization. This allows to absorb sporadic drops in utilization
436 * of an otherwise almost periodic task.
437 *
438 * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg
439 * updates. When a task is dequeued, its util_est should not be updated if its
440 * util_avg has not been updated in the meantime.
441 * This information is mapped into the MSB bit of util_est.enqueued at dequeue
442 * time. Since max value of util_est.enqueued for a task is 1024 (PELT util_avg
443 * for a task) it is safe to use MSB.
444 */
445 struct util_est {
446 unsigned int enqueued;
447 unsigned int ewma;
448 #define UTIL_EST_WEIGHT_SHIFT 2
449 #define UTIL_AVG_UNCHANGED 0x80000000
450 } __attribute__((__aligned__(sizeof(u64))));
451
452 /*
453 * The load/runnable/util_avg accumulates an infinite geometric series
454 * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c).
455 *
456 * [load_avg definition]
457 *
458 * load_avg = runnable% * scale_load_down(load)
459 *
460 * [runnable_avg definition]
461 *
462 * runnable_avg = runnable% * SCHED_CAPACITY_SCALE
463 *
464 * [util_avg definition]
465 *
466 * util_avg = running% * SCHED_CAPACITY_SCALE
467 *
468 * where runnable% is the time ratio that a sched_entity is runnable and
469 * running% the time ratio that a sched_entity is running.
470 *
471 * For cfs_rq, they are the aggregated values of all runnable and blocked
472 * sched_entities.
473 *
474 * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU
475 * capacity scaling. The scaling is done through the rq_clock_pelt that is used
476 * for computing those signals (see update_rq_clock_pelt())
477 *
478 * N.B., the above ratios (runnable% and running%) themselves are in the
479 * range of [0, 1]. To do fixed point arithmetics, we therefore scale them
480 * to as large a range as necessary. This is for example reflected by
481 * util_avg's SCHED_CAPACITY_SCALE.
482 *
483 * [Overflow issue]
484 *
485 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
486 * with the highest load (=88761), always runnable on a single cfs_rq,
487 * and should not overflow as the number already hits PID_MAX_LIMIT.
488 *
489 * For all other cases (including 32-bit kernels), struct load_weight's
490 * weight will overflow first before we do, because:
491 *
492 * Max(load_avg) <= Max(load.weight)
493 *
494 * Then it is the load_weight's responsibility to consider overflow
495 * issues.
496 */
497 struct sched_avg {
498 u64 last_update_time;
499 u64 load_sum;
500 u64 runnable_sum;
501 u32 util_sum;
502 u32 period_contrib;
503 unsigned long load_avg;
504 unsigned long runnable_avg;
505 unsigned long util_avg;
506 struct util_est util_est;
507 } ____cacheline_aligned;
508
509 struct sched_statistics {
510 #ifdef CONFIG_SCHEDSTATS
511 u64 wait_start;
512 u64 wait_max;
513 u64 wait_count;
514 u64 wait_sum;
515 u64 iowait_count;
516 u64 iowait_sum;
517
518 u64 sleep_start;
519 u64 sleep_max;
520 s64 sum_sleep_runtime;
521
522 u64 block_start;
523 u64 block_max;
524 s64 sum_block_runtime;
525
526 s64 exec_max;
527 u64 slice_max;
528
529 u64 nr_migrations_cold;
530 u64 nr_failed_migrations_affine;
531 u64 nr_failed_migrations_running;
532 u64 nr_failed_migrations_hot;
533 u64 nr_forced_migrations;
534
535 u64 nr_wakeups;
536 u64 nr_wakeups_sync;
537 u64 nr_wakeups_migrate;
538 u64 nr_wakeups_local;
539 u64 nr_wakeups_remote;
540 u64 nr_wakeups_affine;
541 u64 nr_wakeups_affine_attempts;
542 u64 nr_wakeups_passive;
543 u64 nr_wakeups_idle;
544
545 #ifdef CONFIG_SCHED_CORE
546 u64 core_forceidle_sum;
547 #endif
548 #endif /* CONFIG_SCHEDSTATS */
549 } ____cacheline_aligned;
550
551 struct sched_entity {
552 /* For load-balancing: */
553 struct load_weight load;
554 struct rb_node run_node;
555 u64 deadline;
556 u64 min_deadline;
557
558 struct list_head group_node;
559 unsigned int on_rq;
560
561 u64 exec_start;
562 u64 sum_exec_runtime;
563 u64 prev_sum_exec_runtime;
564 u64 vruntime;
565 s64 vlag;
566 u64 slice;
567
568 u64 nr_migrations;
569
570 #ifdef CONFIG_FAIR_GROUP_SCHED
571 int depth;
572 struct sched_entity *parent;
573 /* rq on which this entity is (to be) queued: */
574 struct cfs_rq *cfs_rq;
575 /* rq "owned" by this entity/group: */
576 struct cfs_rq *my_q;
577 /* cached value of my_q->h_nr_running */
578 unsigned long runnable_weight;
579 #endif
580
581 #ifdef CONFIG_SMP
582 /*
583 * Per entity load average tracking.
584 *
585 * Put into separate cache line so it does not
586 * collide with read-mostly values above.
587 */
588 struct sched_avg avg;
589 #endif
590 };
591
592 struct sched_rt_entity {
593 struct list_head run_list;
594 unsigned long timeout;
595 unsigned long watchdog_stamp;
596 unsigned int time_slice;
597 unsigned short on_rq;
598 unsigned short on_list;
599
600 struct sched_rt_entity *back;
601 #ifdef CONFIG_RT_GROUP_SCHED
602 struct sched_rt_entity *parent;
603 /* rq on which this entity is (to be) queued: */
604 struct rt_rq *rt_rq;
605 /* rq "owned" by this entity/group: */
606 struct rt_rq *my_q;
607 #endif
608 } __randomize_layout;
609
610 struct sched_dl_entity {
611 struct rb_node rb_node;
612
613 /*
614 * Original scheduling parameters. Copied here from sched_attr
615 * during sched_setattr(), they will remain the same until
616 * the next sched_setattr().
617 */
618 u64 dl_runtime; /* Maximum runtime for each instance */
619 u64 dl_deadline; /* Relative deadline of each instance */
620 u64 dl_period; /* Separation of two instances (period) */
621 u64 dl_bw; /* dl_runtime / dl_period */
622 u64 dl_density; /* dl_runtime / dl_deadline */
623
624 /*
625 * Actual scheduling parameters. Initialized with the values above,
626 * they are continuously updated during task execution. Note that
627 * the remaining runtime could be < 0 in case we are in overrun.
628 */
629 s64 runtime; /* Remaining runtime for this instance */
630 u64 deadline; /* Absolute deadline for this instance */
631 unsigned int flags; /* Specifying the scheduler behaviour */
632
633 /*
634 * Some bool flags:
635 *
636 * @dl_throttled tells if we exhausted the runtime. If so, the
637 * task has to wait for a replenishment to be performed at the
638 * next firing of dl_timer.
639 *
640 * @dl_yielded tells if task gave up the CPU before consuming
641 * all its available runtime during the last job.
642 *
643 * @dl_non_contending tells if the task is inactive while still
644 * contributing to the active utilization. In other words, it
645 * indicates if the inactive timer has been armed and its handler
646 * has not been executed yet. This flag is useful to avoid race
647 * conditions between the inactive timer handler and the wakeup
648 * code.
649 *
650 * @dl_overrun tells if the task asked to be informed about runtime
651 * overruns.
652 */
653 unsigned int dl_throttled : 1;
654 unsigned int dl_yielded : 1;
655 unsigned int dl_non_contending : 1;
656 unsigned int dl_overrun : 1;
657
658 /*
659 * Bandwidth enforcement timer. Each -deadline task has its
660 * own bandwidth to be enforced, thus we need one timer per task.
661 */
662 struct hrtimer dl_timer;
663
664 /*
665 * Inactive timer, responsible for decreasing the active utilization
666 * at the "0-lag time". When a -deadline task blocks, it contributes
667 * to GRUB's active utilization until the "0-lag time", hence a
668 * timer is needed to decrease the active utilization at the correct
669 * time.
670 */
671 struct hrtimer inactive_timer;
672
673 #ifdef CONFIG_RT_MUTEXES
674 /*
675 * Priority Inheritance. When a DEADLINE scheduling entity is boosted
676 * pi_se points to the donor, otherwise points to the dl_se it belongs
677 * to (the original one/itself).
678 */
679 struct sched_dl_entity *pi_se;
680 #endif
681 };
682
683 #ifdef CONFIG_UCLAMP_TASK
684 /* Number of utilization clamp buckets (shorter alias) */
685 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT
686
687 /*
688 * Utilization clamp for a scheduling entity
689 * @value: clamp value "assigned" to a se
690 * @bucket_id: bucket index corresponding to the "assigned" value
691 * @active: the se is currently refcounted in a rq's bucket
692 * @user_defined: the requested clamp value comes from user-space
693 *
694 * The bucket_id is the index of the clamp bucket matching the clamp value
695 * which is pre-computed and stored to avoid expensive integer divisions from
696 * the fast path.
697 *
698 * The active bit is set whenever a task has got an "effective" value assigned,
699 * which can be different from the clamp value "requested" from user-space.
700 * This allows to know a task is refcounted in the rq's bucket corresponding
701 * to the "effective" bucket_id.
702 *
703 * The user_defined bit is set whenever a task has got a task-specific clamp
704 * value requested from userspace, i.e. the system defaults apply to this task
705 * just as a restriction. This allows to relax default clamps when a less
706 * restrictive task-specific value has been requested, thus allowing to
707 * implement a "nice" semantic. For example, a task running with a 20%
708 * default boost can still drop its own boosting to 0%.
709 */
710 struct uclamp_se {
711 unsigned int value : bits_per(SCHED_CAPACITY_SCALE);
712 unsigned int bucket_id : bits_per(UCLAMP_BUCKETS);
713 unsigned int active : 1;
714 unsigned int user_defined : 1;
715 };
716 #endif /* CONFIG_UCLAMP_TASK */
717
718 union rcu_special {
719 struct {
720 u8 blocked;
721 u8 need_qs;
722 u8 exp_hint; /* Hint for performance. */
723 u8 need_mb; /* Readers need smp_mb(). */
724 } b; /* Bits. */
725 u32 s; /* Set of bits. */
726 };
727
728 enum perf_event_task_context {
729 perf_invalid_context = -1,
730 perf_hw_context = 0,
731 perf_sw_context,
732 perf_nr_task_contexts,
733 };
734
735 struct wake_q_node {
736 struct wake_q_node *next;
737 };
738
739 struct kmap_ctrl {
740 #ifdef CONFIG_KMAP_LOCAL
741 int idx;
742 pte_t pteval[KM_MAX_IDX];
743 #endif
744 };
745
746 struct task_struct {
747 #ifdef CONFIG_THREAD_INFO_IN_TASK
748 /*
749 * For reasons of header soup (see current_thread_info()), this
750 * must be the first element of task_struct.
751 */
752 struct thread_info thread_info;
753 #endif
754 unsigned int __state;
755
756 #ifdef CONFIG_PREEMPT_RT
757 /* saved state for "spinlock sleepers" */
758 unsigned int saved_state;
759 #endif
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 const struct sched_class *sched_class;
801
802 #ifdef CONFIG_SCHED_CORE
803 struct rb_node core_node;
804 unsigned long core_cookie;
805 unsigned int core_occupation;
806 #endif
807
808 #ifdef CONFIG_CGROUP_SCHED
809 struct task_group *sched_task_group;
810 #endif
811
812 #ifdef CONFIG_UCLAMP_TASK
813 /*
814 * Clamp values requested for a scheduling entity.
815 * Must be updated with task_rq_lock() held.
816 */
817 struct uclamp_se uclamp_req[UCLAMP_CNT];
818 /*
819 * Effective clamp values used for a scheduling entity.
820 * Must be updated with task_rq_lock() held.
821 */
822 struct uclamp_se uclamp[UCLAMP_CNT];
823 #endif
824
825 struct sched_statistics stats;
826
827 #ifdef CONFIG_PREEMPT_NOTIFIERS
828 /* List of struct preempt_notifier: */
829 struct hlist_head preempt_notifiers;
830 #endif
831
832 #ifdef CONFIG_BLK_DEV_IO_TRACE
833 unsigned int btrace_seq;
834 #endif
835
836 unsigned int policy;
837 int nr_cpus_allowed;
838 const cpumask_t *cpus_ptr;
839 cpumask_t *user_cpus_ptr;
840 cpumask_t cpus_mask;
841 void *migration_pending;
842 #ifdef CONFIG_SMP
843 unsigned short migration_disabled;
844 #endif
845 unsigned short migration_flags;
846
847 #ifdef CONFIG_PREEMPT_RCU
848 int rcu_read_lock_nesting;
849 union rcu_special rcu_read_unlock_special;
850 struct list_head rcu_node_entry;
851 struct rcu_node *rcu_blocked_node;
852 #endif /* #ifdef CONFIG_PREEMPT_RCU */
853
854 #ifdef CONFIG_TASKS_RCU
855 unsigned long rcu_tasks_nvcsw;
856 u8 rcu_tasks_holdout;
857 u8 rcu_tasks_idx;
858 int rcu_tasks_idle_cpu;
859 struct list_head rcu_tasks_holdout_list;
860 int rcu_tasks_exit_cpu;
861 struct list_head rcu_tasks_exit_list;
862 #endif /* #ifdef CONFIG_TASKS_RCU */
863
864 #ifdef CONFIG_TASKS_TRACE_RCU
865 int trc_reader_nesting;
866 int trc_ipi_to_cpu;
867 union rcu_special trc_reader_special;
868 struct list_head trc_holdout_list;
869 struct list_head trc_blkd_node;
870 int trc_blkd_cpu;
871 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
872
873 struct sched_info sched_info;
874
875 struct list_head tasks;
876 #ifdef CONFIG_SMP
877 struct plist_node pushable_tasks;
878 struct rb_node pushable_dl_tasks;
879 #endif
880
881 struct mm_struct *mm;
882 struct mm_struct *active_mm;
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 unsigned sched_task_hot:1;
900
901 /* Force alignment to the next boundary: */
902 unsigned :0;
903
904 /* Unserialized, strictly 'current' */
905
906 /*
907 * This field must not be in the scheduler word above due to wakelist
908 * queueing no longer being serialized by p->on_cpu. However:
909 *
910 * p->XXX = X; ttwu()
911 * schedule() if (p->on_rq && ..) // false
912 * smp_mb__after_spinlock(); if (smp_load_acquire(&p->on_cpu) && //true
913 * deactivate_task() ttwu_queue_wakelist())
914 * p->on_rq = 0; p->sched_remote_wakeup = Y;
915 *
916 * guarantees all stores of 'current' are visible before
917 * ->sched_remote_wakeup gets used, so it can be in this word.
918 */
919 unsigned sched_remote_wakeup:1;
920
921 /* Bit to tell LSMs we're in execve(): */
922 unsigned in_execve:1;
923 unsigned in_iowait:1;
924 #ifndef TIF_RESTORE_SIGMASK
925 unsigned restore_sigmask:1;
926 #endif
927 #ifdef CONFIG_MEMCG
928 unsigned in_user_fault:1;
929 #endif
930 #ifdef CONFIG_LRU_GEN
931 /* whether the LRU algorithm may apply to this access */
932 unsigned in_lru_fault:1;
933 #endif
934 #ifdef CONFIG_COMPAT_BRK
935 unsigned brk_randomized:1;
936 #endif
937 #ifdef CONFIG_CGROUPS
938 /* disallow userland-initiated cgroup migration */
939 unsigned no_cgroup_migration:1;
940 /* task is frozen/stopped (used by the cgroup freezer) */
941 unsigned frozen:1;
942 #endif
943 #ifdef CONFIG_BLK_CGROUP
944 unsigned use_memdelay:1;
945 #endif
946 #ifdef CONFIG_PSI
947 /* Stalled due to lack of memory */
948 unsigned in_memstall:1;
949 #endif
950 #ifdef CONFIG_PAGE_OWNER
951 /* Used by page_owner=on to detect recursion in page tracking. */
952 unsigned in_page_owner:1;
953 #endif
954 #ifdef CONFIG_EVENTFD
955 /* Recursion prevention for eventfd_signal() */
956 unsigned in_eventfd:1;
957 #endif
958 #ifdef CONFIG_IOMMU_SVA
959 unsigned pasid_activated:1;
960 #endif
961 #ifdef CONFIG_CPU_SUP_INTEL
962 unsigned reported_split_lock:1;
963 #endif
964 #ifdef CONFIG_TASK_DELAY_ACCT
965 /* delay due to memory thrashing */
966 unsigned in_thrashing:1;
967 #endif
968
969 unsigned long atomic_flags; /* Flags requiring atomic access. */
970
971 struct restart_block restart_block;
972
973 pid_t pid;
974 pid_t tgid;
975
976 #ifdef CONFIG_STACKPROTECTOR
977 /* Canary value for the -fstack-protector GCC feature: */
978 unsigned long stack_canary;
979 #endif
980 /*
981 * Pointers to the (original) parent process, youngest child, younger sibling,
982 * older sibling, respectively. (p->father can be replaced with
983 * p->real_parent->pid)
984 */
985
986 /* Real parent process: */
987 struct task_struct __rcu *real_parent;
988
989 /* Recipient of SIGCHLD, wait4() reports: */
990 struct task_struct __rcu *parent;
991
992 /*
993 * Children/sibling form the list of natural children:
994 */
995 struct list_head children;
996 struct list_head sibling;
997 struct task_struct *group_leader;
998
999 /*
1000 * 'ptraced' is the list of tasks this task is using ptrace() on.
1001 *
1002 * This includes both natural children and PTRACE_ATTACH targets.
1003 * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
1004 */
1005 struct list_head ptraced;
1006 struct list_head ptrace_entry;
1007
1008 /* PID/PID hash table linkage. */
1009 struct pid *thread_pid;
1010 struct hlist_node pid_links[PIDTYPE_MAX];
1011 struct list_head thread_group;
1012 struct list_head thread_node;
1013
1014 struct completion *vfork_done;
1015
1016 /* CLONE_CHILD_SETTID: */
1017 int __user *set_child_tid;
1018
1019 /* CLONE_CHILD_CLEARTID: */
1020 int __user *clear_child_tid;
1021
1022 /* PF_KTHREAD | PF_IO_WORKER */
1023 void *worker_private;
1024
1025 u64 utime;
1026 u64 stime;
1027 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
1028 u64 utimescaled;
1029 u64 stimescaled;
1030 #endif
1031 u64 gtime;
1032 struct prev_cputime prev_cputime;
1033 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1034 struct vtime vtime;
1035 #endif
1036
1037 #ifdef CONFIG_NO_HZ_FULL
1038 atomic_t tick_dep_mask;
1039 #endif
1040 /* Context switch counts: */
1041 unsigned long nvcsw;
1042 unsigned long nivcsw;
1043
1044 /* Monotonic time in nsecs: */
1045 u64 start_time;
1046
1047 /* Boot based time in nsecs: */
1048 u64 start_boottime;
1049
1050 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
1051 unsigned long min_flt;
1052 unsigned long maj_flt;
1053
1054 /* Empty if CONFIG_POSIX_CPUTIMERS=n */
1055 struct posix_cputimers posix_cputimers;
1056
1057 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK
1058 struct posix_cputimers_work posix_cputimers_work;
1059 #endif
1060
1061 /* Process credentials: */
1062
1063 /* Tracer's credentials at attach: */
1064 const struct cred __rcu *ptracer_cred;
1065
1066 /* Objective and real subjective task credentials (COW): */
1067 const struct cred __rcu *real_cred;
1068
1069 /* Effective (overridable) subjective task credentials (COW): */
1070 const struct cred __rcu *cred;
1071
1072 #ifdef CONFIG_KEYS
1073 /* Cached requested key. */
1074 struct key *cached_requested_key;
1075 #endif
1076
1077 /*
1078 * executable name, excluding path.
1079 *
1080 * - normally initialized setup_new_exec()
1081 * - access it with [gs]et_task_comm()
1082 * - lock it with task_lock()
1083 */
1084 char comm[TASK_COMM_LEN];
1085
1086 struct nameidata *nameidata;
1087
1088 #ifdef CONFIG_SYSVIPC
1089 struct sysv_sem sysvsem;
1090 struct sysv_shm sysvshm;
1091 #endif
1092 #ifdef CONFIG_DETECT_HUNG_TASK
1093 unsigned long last_switch_count;
1094 unsigned long last_switch_time;
1095 #endif
1096 /* Filesystem information: */
1097 struct fs_struct *fs;
1098
1099 /* Open file information: */
1100 struct files_struct *files;
1101
1102 #ifdef CONFIG_IO_URING
1103 struct io_uring_task *io_uring;
1104 #endif
1105
1106 /* Namespaces: */
1107 struct nsproxy *nsproxy;
1108
1109 /* Signal handlers: */
1110 struct signal_struct *signal;
1111 struct sighand_struct __rcu *sighand;
1112 sigset_t blocked;
1113 sigset_t real_blocked;
1114 /* Restored if set_restore_sigmask() was used: */
1115 sigset_t saved_sigmask;
1116 struct sigpending pending;
1117 unsigned long sas_ss_sp;
1118 size_t sas_ss_size;
1119 unsigned int sas_ss_flags;
1120
1121 struct callback_head *task_works;
1122
1123 #ifdef CONFIG_AUDIT
1124 #ifdef CONFIG_AUDITSYSCALL
1125 struct audit_context *audit_context;
1126 #endif
1127 kuid_t loginuid;
1128 unsigned int sessionid;
1129 #endif
1130 struct seccomp seccomp;
1131 struct syscall_user_dispatch syscall_dispatch;
1132
1133 /* Thread group tracking: */
1134 u64 parent_exec_id;
1135 u64 self_exec_id;
1136
1137 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
1138 spinlock_t alloc_lock;
1139
1140 /* Protection of the PI data structures: */
1141 raw_spinlock_t pi_lock;
1142
1143 struct wake_q_node wake_q;
1144
1145 #ifdef CONFIG_RT_MUTEXES
1146 /* PI waiters blocked on a rt_mutex held by this task: */
1147 struct rb_root_cached pi_waiters;
1148 /* Updated under owner's pi_lock and rq lock */
1149 struct task_struct *pi_top_task;
1150 /* Deadlock detection and priority inheritance handling: */
1151 struct rt_mutex_waiter *pi_blocked_on;
1152 #endif
1153
1154 #ifdef CONFIG_DEBUG_MUTEXES
1155 /* Mutex deadlock detection: */
1156 struct mutex_waiter *blocked_on;
1157 #endif
1158
1159 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1160 int non_block_count;
1161 #endif
1162
1163 #ifdef CONFIG_TRACE_IRQFLAGS
1164 struct irqtrace_events irqtrace;
1165 unsigned int hardirq_threaded;
1166 u64 hardirq_chain_key;
1167 int softirqs_enabled;
1168 int softirq_context;
1169 int irq_config;
1170 #endif
1171 #ifdef CONFIG_PREEMPT_RT
1172 int softirq_disable_cnt;
1173 #endif
1174
1175 #ifdef CONFIG_LOCKDEP
1176 # define MAX_LOCK_DEPTH 48UL
1177 u64 curr_chain_key;
1178 int lockdep_depth;
1179 unsigned int lockdep_recursion;
1180 struct held_lock held_locks[MAX_LOCK_DEPTH];
1181 #endif
1182
1183 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP)
1184 unsigned int in_ubsan;
1185 #endif
1186
1187 /* Journalling filesystem info: */
1188 void *journal_info;
1189
1190 /* Stacked block device info: */
1191 struct bio_list *bio_list;
1192
1193 /* Stack plugging: */
1194 struct blk_plug *plug;
1195
1196 /* VM state: */
1197 struct reclaim_state *reclaim_state;
1198
1199 struct io_context *io_context;
1200
1201 #ifdef CONFIG_COMPACTION
1202 struct capture_control *capture_control;
1203 #endif
1204 /* Ptrace state: */
1205 unsigned long ptrace_message;
1206 kernel_siginfo_t *last_siginfo;
1207
1208 struct task_io_accounting ioac;
1209 #ifdef CONFIG_PSI
1210 /* Pressure stall state */
1211 unsigned int psi_flags;
1212 #endif
1213 #ifdef CONFIG_TASK_XACCT
1214 /* Accumulated RSS usage: */
1215 u64 acct_rss_mem1;
1216 /* Accumulated virtual memory usage: */
1217 u64 acct_vm_mem1;
1218 /* stime + utime since last update: */
1219 u64 acct_timexpd;
1220 #endif
1221 #ifdef CONFIG_CPUSETS
1222 /* Protected by ->alloc_lock: */
1223 nodemask_t mems_allowed;
1224 /* Sequence number to catch updates: */
1225 seqcount_spinlock_t mems_allowed_seq;
1226 int cpuset_mem_spread_rotor;
1227 int cpuset_slab_spread_rotor;
1228 #endif
1229 #ifdef CONFIG_CGROUPS
1230 /* Control Group info protected by css_set_lock: */
1231 struct css_set __rcu *cgroups;
1232 /* cg_list protected by css_set_lock and tsk->alloc_lock: */
1233 struct list_head cg_list;
1234 #endif
1235 #ifdef CONFIG_X86_CPU_RESCTRL
1236 u32 closid;
1237 u32 rmid;
1238 #endif
1239 #ifdef CONFIG_FUTEX
1240 struct robust_list_head __user *robust_list;
1241 #ifdef CONFIG_COMPAT
1242 struct compat_robust_list_head __user *compat_robust_list;
1243 #endif
1244 struct list_head pi_state_list;
1245 struct futex_pi_state *pi_state_cache;
1246 struct mutex futex_exit_mutex;
1247 unsigned int futex_state;
1248 #endif
1249 #ifdef CONFIG_PERF_EVENTS
1250 struct perf_event_context *perf_event_ctxp;
1251 struct mutex perf_event_mutex;
1252 struct list_head perf_event_list;
1253 #endif
1254 #ifdef CONFIG_DEBUG_PREEMPT
1255 unsigned long preempt_disable_ip;
1256 #endif
1257 #ifdef CONFIG_NUMA
1258 /* Protected by alloc_lock: */
1259 struct mempolicy *mempolicy;
1260 short il_prev;
1261 short pref_node_fork;
1262 #endif
1263 #ifdef CONFIG_NUMA_BALANCING
1264 int numa_scan_seq;
1265 unsigned int numa_scan_period;
1266 unsigned int numa_scan_period_max;
1267 int numa_preferred_nid;
1268 unsigned long numa_migrate_retry;
1269 /* Migration stamp: */
1270 u64 node_stamp;
1271 u64 last_task_numa_placement;
1272 u64 last_sum_exec_runtime;
1273 struct callback_head numa_work;
1274
1275 /*
1276 * This pointer is only modified for current in syscall and
1277 * pagefault context (and for tasks being destroyed), so it can be read
1278 * from any of the following contexts:
1279 * - RCU read-side critical section
1280 * - current->numa_group from everywhere
1281 * - task's runqueue locked, task not running
1282 */
1283 struct numa_group __rcu *numa_group;
1284
1285 /*
1286 * numa_faults is an array split into four regions:
1287 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1288 * in this precise order.
1289 *
1290 * faults_memory: Exponential decaying average of faults on a per-node
1291 * basis. Scheduling placement decisions are made based on these
1292 * counts. The values remain static for the duration of a PTE scan.
1293 * faults_cpu: Track the nodes the process was running on when a NUMA
1294 * hinting fault was incurred.
1295 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1296 * during the current scan window. When the scan completes, the counts
1297 * in faults_memory and faults_cpu decay and these values are copied.
1298 */
1299 unsigned long *numa_faults;
1300 unsigned long total_numa_faults;
1301
1302 /*
1303 * numa_faults_locality tracks if faults recorded during the last
1304 * scan window were remote/local or failed to migrate. The task scan
1305 * period is adapted based on the locality of the faults with different
1306 * weights depending on whether they were shared or private faults
1307 */
1308 unsigned long numa_faults_locality[3];
1309
1310 unsigned long numa_pages_migrated;
1311 #endif /* CONFIG_NUMA_BALANCING */
1312
1313 #ifdef CONFIG_RSEQ
1314 struct rseq __user *rseq;
1315 u32 rseq_len;
1316 u32 rseq_sig;
1317 /*
1318 * RmW on rseq_event_mask must be performed atomically
1319 * with respect to preemption.
1320 */
1321 unsigned long rseq_event_mask;
1322 #endif
1323
1324 #ifdef CONFIG_SCHED_MM_CID
1325 int mm_cid; /* Current cid in mm */
1326 int last_mm_cid; /* Most recent cid in mm */
1327 int migrate_from_cpu;
1328 int mm_cid_active; /* Whether cid bitmap is active */
1329 struct callback_head cid_work;
1330 #endif
1331
1332 struct tlbflush_unmap_batch tlb_ubc;
1333
1334 /* Cache last used pipe for splice(): */
1335 struct pipe_inode_info *splice_pipe;
1336
1337 struct page_frag task_frag;
1338
1339 #ifdef CONFIG_TASK_DELAY_ACCT
1340 struct task_delay_info *delays;
1341 #endif
1342
1343 #ifdef CONFIG_FAULT_INJECTION
1344 int make_it_fail;
1345 unsigned int fail_nth;
1346 #endif
1347 /*
1348 * When (nr_dirtied >= nr_dirtied_pause), it's time to call
1349 * balance_dirty_pages() for a dirty throttling pause:
1350 */
1351 int nr_dirtied;
1352 int nr_dirtied_pause;
1353 /* Start of a write-and-pause period: */
1354 unsigned long dirty_paused_when;
1355
1356 #ifdef CONFIG_LATENCYTOP
1357 int latency_record_count;
1358 struct latency_record latency_record[LT_SAVECOUNT];
1359 #endif
1360 /*
1361 * Time slack values; these are used to round up poll() and
1362 * select() etc timeout values. These are in nanoseconds.
1363 */
1364 u64 timer_slack_ns;
1365 u64 default_timer_slack_ns;
1366
1367 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
1368 unsigned int kasan_depth;
1369 #endif
1370
1371 #ifdef CONFIG_KCSAN
1372 struct kcsan_ctx kcsan_ctx;
1373 #ifdef CONFIG_TRACE_IRQFLAGS
1374 struct irqtrace_events kcsan_save_irqtrace;
1375 #endif
1376 #ifdef CONFIG_KCSAN_WEAK_MEMORY
1377 int kcsan_stack_depth;
1378 #endif
1379 #endif
1380
1381 #ifdef CONFIG_KMSAN
1382 struct kmsan_ctx kmsan_ctx;
1383 #endif
1384
1385 #if IS_ENABLED(CONFIG_KUNIT)
1386 struct kunit *kunit_test;
1387 #endif
1388
1389 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1390 /* Index of current stored address in ret_stack: */
1391 int curr_ret_stack;
1392 int curr_ret_depth;
1393
1394 /* Stack of return addresses for return function tracing: */
1395 struct ftrace_ret_stack *ret_stack;
1396
1397 /* Timestamp for last schedule: */
1398 unsigned long long ftrace_timestamp;
1399
1400 /*
1401 * Number of functions that haven't been traced
1402 * because of depth overrun:
1403 */
1404 atomic_t trace_overrun;
1405
1406 /* Pause tracing: */
1407 atomic_t tracing_graph_pause;
1408 #endif
1409
1410 #ifdef CONFIG_TRACING
1411 /* Bitmask and counter of trace recursion: */
1412 unsigned long trace_recursion;
1413 #endif /* CONFIG_TRACING */
1414
1415 #ifdef CONFIG_KCOV
1416 /* See kernel/kcov.c for more details. */
1417
1418 /* Coverage collection mode enabled for this task (0 if disabled): */
1419 unsigned int kcov_mode;
1420
1421 /* Size of the kcov_area: */
1422 unsigned int kcov_size;
1423
1424 /* Buffer for coverage collection: */
1425 void *kcov_area;
1426
1427 /* KCOV descriptor wired with this task or NULL: */
1428 struct kcov *kcov;
1429
1430 /* KCOV common handle for remote coverage collection: */
1431 u64 kcov_handle;
1432
1433 /* KCOV sequence number: */
1434 int kcov_sequence;
1435
1436 /* Collect coverage from softirq context: */
1437 unsigned int kcov_softirq;
1438 #endif
1439
1440 #ifdef CONFIG_MEMCG
1441 struct mem_cgroup *memcg_in_oom;
1442 gfp_t memcg_oom_gfp_mask;
1443 int memcg_oom_order;
1444
1445 /* Number of pages to reclaim on returning to userland: */
1446 unsigned int memcg_nr_pages_over_high;
1447
1448 /* Used by memcontrol for targeted memcg charge: */
1449 struct mem_cgroup *active_memcg;
1450 #endif
1451
1452 #ifdef CONFIG_BLK_CGROUP
1453 struct gendisk *throttle_disk;
1454 #endif
1455
1456 #ifdef CONFIG_UPROBES
1457 struct uprobe_task *utask;
1458 #endif
1459 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1460 unsigned int sequential_io;
1461 unsigned int sequential_io_avg;
1462 #endif
1463 struct kmap_ctrl kmap_ctrl;
1464 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1465 unsigned long task_state_change;
1466 # ifdef CONFIG_PREEMPT_RT
1467 unsigned long saved_state_change;
1468 # endif
1469 #endif
1470 struct rcu_head rcu;
1471 refcount_t rcu_users;
1472 int pagefault_disabled;
1473 #ifdef CONFIG_MMU
1474 struct task_struct *oom_reaper_list;
1475 struct timer_list oom_reaper_timer;
1476 #endif
1477 #ifdef CONFIG_VMAP_STACK
1478 struct vm_struct *stack_vm_area;
1479 #endif
1480 #ifdef CONFIG_THREAD_INFO_IN_TASK
1481 /* A live task holds one reference: */
1482 refcount_t stack_refcount;
1483 #endif
1484 #ifdef CONFIG_LIVEPATCH
1485 int patch_state;
1486 #endif
1487 #ifdef CONFIG_SECURITY
1488 /* Used by LSM modules for access restriction: */
1489 void *security;
1490 #endif
1491 #ifdef CONFIG_BPF_SYSCALL
1492 /* Used by BPF task local storage */
1493 struct bpf_local_storage __rcu *bpf_storage;
1494 /* Used for BPF run context */
1495 struct bpf_run_ctx *bpf_ctx;
1496 #endif
1497
1498 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK
1499 unsigned long lowest_stack;
1500 unsigned long prev_lowest_stack;
1501 #endif
1502
1503 #ifdef CONFIG_X86_MCE
1504 void __user *mce_vaddr;
1505 __u64 mce_kflags;
1506 u64 mce_addr;
1507 __u64 mce_ripv : 1,
1508 mce_whole_page : 1,
1509 __mce_reserved : 62;
1510 struct callback_head mce_kill_me;
1511 int mce_count;
1512 #endif
1513
1514 #ifdef CONFIG_KRETPROBES
1515 struct llist_head kretprobe_instances;
1516 #endif
1517 #ifdef CONFIG_RETHOOK
1518 struct llist_head rethooks;
1519 #endif
1520
1521 #ifdef CONFIG_ARCH_HAS_PARANOID_L1D_FLUSH
1522 /*
1523 * If L1D flush is supported on mm context switch
1524 * then we use this callback head to queue kill work
1525 * to kill tasks that are not running on SMT disabled
1526 * cores
1527 */
1528 struct callback_head l1d_flush_kill;
1529 #endif
1530
1531 #ifdef CONFIG_RV
1532 /*
1533 * Per-task RV monitor. Nowadays fixed in RV_PER_TASK_MONITORS.
1534 * If we find justification for more monitors, we can think
1535 * about adding more or developing a dynamic method. So far,
1536 * none of these are justified.
1537 */
1538 union rv_task_monitor rv[RV_PER_TASK_MONITORS];
1539 #endif
1540
1541 #ifdef CONFIG_USER_EVENTS
1542 struct user_event_mm *user_event_mm;
1543 #endif
1544
1545 /*
1546 * New fields for task_struct should be added above here, so that
1547 * they are included in the randomized portion of task_struct.
1548 */
1549 randomized_struct_fields_end
1550
1551 /* CPU-specific state of this task: */
1552 struct thread_struct thread;
1553
1554 /*
1555 * WARNING: on x86, 'thread_struct' contains a variable-sized
1556 * structure. It *MUST* be at the end of 'task_struct'.
1557 *
1558 * Do not put anything below here!
1559 */
1560 };
1561
task_pid(struct task_struct * task)1562 static inline struct pid *task_pid(struct task_struct *task)
1563 {
1564 return task->thread_pid;
1565 }
1566
1567 /*
1568 * the helpers to get the task's different pids as they are seen
1569 * from various namespaces
1570 *
1571 * task_xid_nr() : global id, i.e. the id seen from the init namespace;
1572 * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of
1573 * current.
1574 * task_xid_nr_ns() : id seen from the ns specified;
1575 *
1576 * see also pid_nr() etc in include/linux/pid.h
1577 */
1578 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns);
1579
task_pid_nr(struct task_struct * tsk)1580 static inline pid_t task_pid_nr(struct task_struct *tsk)
1581 {
1582 return tsk->pid;
1583 }
1584
task_pid_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1585 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1586 {
1587 return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1588 }
1589
task_pid_vnr(struct task_struct * tsk)1590 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1591 {
1592 return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1593 }
1594
1595
task_tgid_nr(struct task_struct * tsk)1596 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1597 {
1598 return tsk->tgid;
1599 }
1600
1601 /**
1602 * pid_alive - check that a task structure is not stale
1603 * @p: Task structure to be checked.
1604 *
1605 * Test if a process is not yet dead (at most zombie state)
1606 * If pid_alive fails, then pointers within the task structure
1607 * can be stale and must not be dereferenced.
1608 *
1609 * Return: 1 if the process is alive. 0 otherwise.
1610 */
pid_alive(const struct task_struct * p)1611 static inline int pid_alive(const struct task_struct *p)
1612 {
1613 return p->thread_pid != NULL;
1614 }
1615
task_pgrp_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1616 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1617 {
1618 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1619 }
1620
task_pgrp_vnr(struct task_struct * tsk)1621 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1622 {
1623 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1624 }
1625
1626
task_session_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1627 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1628 {
1629 return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1630 }
1631
task_session_vnr(struct task_struct * tsk)1632 static inline pid_t task_session_vnr(struct task_struct *tsk)
1633 {
1634 return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1635 }
1636
task_tgid_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1637 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1638 {
1639 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, ns);
1640 }
1641
task_tgid_vnr(struct task_struct * tsk)1642 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1643 {
1644 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, NULL);
1645 }
1646
task_ppid_nr_ns(const struct task_struct * tsk,struct pid_namespace * ns)1647 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1648 {
1649 pid_t pid = 0;
1650
1651 rcu_read_lock();
1652 if (pid_alive(tsk))
1653 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1654 rcu_read_unlock();
1655
1656 return pid;
1657 }
1658
task_ppid_nr(const struct task_struct * tsk)1659 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1660 {
1661 return task_ppid_nr_ns(tsk, &init_pid_ns);
1662 }
1663
1664 /* Obsolete, do not use: */
task_pgrp_nr(struct task_struct * tsk)1665 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1666 {
1667 return task_pgrp_nr_ns(tsk, &init_pid_ns);
1668 }
1669
1670 #define TASK_REPORT_IDLE (TASK_REPORT + 1)
1671 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1)
1672
__task_state_index(unsigned int tsk_state,unsigned int tsk_exit_state)1673 static inline unsigned int __task_state_index(unsigned int tsk_state,
1674 unsigned int tsk_exit_state)
1675 {
1676 unsigned int state = (tsk_state | tsk_exit_state) & TASK_REPORT;
1677
1678 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX);
1679
1680 if ((tsk_state & TASK_IDLE) == TASK_IDLE)
1681 state = TASK_REPORT_IDLE;
1682
1683 /*
1684 * We're lying here, but rather than expose a completely new task state
1685 * to userspace, we can make this appear as if the task has gone through
1686 * a regular rt_mutex_lock() call.
1687 * Report frozen tasks as uninterruptible.
1688 */
1689 if ((tsk_state & TASK_RTLOCK_WAIT) || (tsk_state & TASK_FROZEN))
1690 state = TASK_UNINTERRUPTIBLE;
1691
1692 return fls(state);
1693 }
1694
task_state_index(struct task_struct * tsk)1695 static inline unsigned int task_state_index(struct task_struct *tsk)
1696 {
1697 return __task_state_index(READ_ONCE(tsk->__state), tsk->exit_state);
1698 }
1699
task_index_to_char(unsigned int state)1700 static inline char task_index_to_char(unsigned int state)
1701 {
1702 static const char state_char[] = "RSDTtXZPI";
1703
1704 BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1);
1705
1706 return state_char[state];
1707 }
1708
task_state_to_char(struct task_struct * tsk)1709 static inline char task_state_to_char(struct task_struct *tsk)
1710 {
1711 return task_index_to_char(task_state_index(tsk));
1712 }
1713
1714 /**
1715 * is_global_init - check if a task structure is init. Since init
1716 * is free to have sub-threads we need to check tgid.
1717 * @tsk: Task structure to be checked.
1718 *
1719 * Check if a task structure is the first user space task the kernel created.
1720 *
1721 * Return: 1 if the task structure is init. 0 otherwise.
1722 */
is_global_init(struct task_struct * tsk)1723 static inline int is_global_init(struct task_struct *tsk)
1724 {
1725 return task_tgid_nr(tsk) == 1;
1726 }
1727
1728 extern struct pid *cad_pid;
1729
1730 /*
1731 * Per process flags
1732 */
1733 #define PF_VCPU 0x00000001 /* I'm a virtual CPU */
1734 #define PF_IDLE 0x00000002 /* I am an IDLE thread */
1735 #define PF_EXITING 0x00000004 /* Getting shut down */
1736 #define PF_POSTCOREDUMP 0x00000008 /* Coredumps should ignore this task */
1737 #define PF_IO_WORKER 0x00000010 /* Task is an IO worker */
1738 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */
1739 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */
1740 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */
1741 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */
1742 #define PF_DUMPCORE 0x00000200 /* Dumped core */
1743 #define PF_SIGNALED 0x00000400 /* Killed by a signal */
1744 #define PF_MEMALLOC 0x00000800 /* Allocating memory */
1745 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */
1746 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */
1747 #define PF_USER_WORKER 0x00004000 /* Kernel thread cloned from userspace thread */
1748 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */
1749 #define PF__HOLE__00010000 0x00010000
1750 #define PF_KSWAPD 0x00020000 /* I am kswapd */
1751 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocation requests will inherit GFP_NOFS */
1752 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocation requests will inherit GFP_NOIO */
1753 #define PF_LOCAL_THROTTLE 0x00100000 /* Throttle writes only against the bdi I write to,
1754 * I am cleaning dirty pages from some other bdi. */
1755 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */
1756 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */
1757 #define PF__HOLE__00800000 0x00800000
1758 #define PF__HOLE__01000000 0x01000000
1759 #define PF__HOLE__02000000 0x02000000
1760 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */
1761 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */
1762 #define PF_MEMALLOC_PIN 0x10000000 /* Allocation context constrained to zones which allow long term pinning. */
1763 #define PF__HOLE__20000000 0x20000000
1764 #define PF__HOLE__40000000 0x40000000
1765 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */
1766
1767 /*
1768 * Only the _current_ task can read/write to tsk->flags, but other
1769 * tasks can access tsk->flags in readonly mode for example
1770 * with tsk_used_math (like during threaded core dumping).
1771 * There is however an exception to this rule during ptrace
1772 * or during fork: the ptracer task is allowed to write to the
1773 * child->flags of its traced child (same goes for fork, the parent
1774 * can write to the child->flags), because we're guaranteed the
1775 * child is not running and in turn not changing child->flags
1776 * at the same time the parent does it.
1777 */
1778 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1779 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1780 #define clear_used_math() clear_stopped_child_used_math(current)
1781 #define set_used_math() set_stopped_child_used_math(current)
1782
1783 #define conditional_stopped_child_used_math(condition, child) \
1784 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1785
1786 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current)
1787
1788 #define copy_to_stopped_child_used_math(child) \
1789 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1790
1791 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1792 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1793 #define used_math() tsk_used_math(current)
1794
is_percpu_thread(void)1795 static __always_inline bool is_percpu_thread(void)
1796 {
1797 #ifdef CONFIG_SMP
1798 return (current->flags & PF_NO_SETAFFINITY) &&
1799 (current->nr_cpus_allowed == 1);
1800 #else
1801 return true;
1802 #endif
1803 }
1804
1805 /* Per-process atomic flags. */
1806 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */
1807 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */
1808 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */
1809 #define PFA_SPEC_SSB_DISABLE 3 /* Speculative Store Bypass disabled */
1810 #define PFA_SPEC_SSB_FORCE_DISABLE 4 /* Speculative Store Bypass force disabled*/
1811 #define PFA_SPEC_IB_DISABLE 5 /* Indirect branch speculation restricted */
1812 #define PFA_SPEC_IB_FORCE_DISABLE 6 /* Indirect branch speculation permanently restricted */
1813 #define PFA_SPEC_SSB_NOEXEC 7 /* Speculative Store Bypass clear on execve() */
1814
1815 #define TASK_PFA_TEST(name, func) \
1816 static inline bool task_##func(struct task_struct *p) \
1817 { return test_bit(PFA_##name, &p->atomic_flags); }
1818
1819 #define TASK_PFA_SET(name, func) \
1820 static inline void task_set_##func(struct task_struct *p) \
1821 { set_bit(PFA_##name, &p->atomic_flags); }
1822
1823 #define TASK_PFA_CLEAR(name, func) \
1824 static inline void task_clear_##func(struct task_struct *p) \
1825 { clear_bit(PFA_##name, &p->atomic_flags); }
1826
TASK_PFA_TEST(NO_NEW_PRIVS,no_new_privs)1827 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
1828 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
1829
1830 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
1831 TASK_PFA_SET(SPREAD_PAGE, spread_page)
1832 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
1833
1834 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
1835 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
1836 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
1837
1838 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable)
1839 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable)
1840 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable)
1841
1842 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1843 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1844 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1845
1846 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1847 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1848
1849 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable)
1850 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable)
1851 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable)
1852
1853 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1854 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1855
1856 static inline void
1857 current_restore_flags(unsigned long orig_flags, unsigned long flags)
1858 {
1859 current->flags &= ~flags;
1860 current->flags |= orig_flags & flags;
1861 }
1862
1863 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
1864 extern int task_can_attach(struct task_struct *p);
1865 extern int dl_bw_alloc(int cpu, u64 dl_bw);
1866 extern void dl_bw_free(int cpu, u64 dl_bw);
1867 #ifdef CONFIG_SMP
1868
1869 /* do_set_cpus_allowed() - consider using set_cpus_allowed_ptr() instead */
1870 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
1871
1872 /**
1873 * set_cpus_allowed_ptr - set CPU affinity mask of a task
1874 * @p: the task
1875 * @new_mask: CPU affinity mask
1876 *
1877 * Return: zero if successful, or a negative error code
1878 */
1879 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
1880 extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node);
1881 extern void release_user_cpus_ptr(struct task_struct *p);
1882 extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask);
1883 extern void force_compatible_cpus_allowed_ptr(struct task_struct *p);
1884 extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p);
1885 #else
do_set_cpus_allowed(struct task_struct * p,const struct cpumask * new_mask)1886 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
1887 {
1888 }
set_cpus_allowed_ptr(struct task_struct * p,const struct cpumask * new_mask)1889 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
1890 {
1891 if (!cpumask_test_cpu(0, new_mask))
1892 return -EINVAL;
1893 return 0;
1894 }
dup_user_cpus_ptr(struct task_struct * dst,struct task_struct * src,int node)1895 static inline int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node)
1896 {
1897 if (src->user_cpus_ptr)
1898 return -EINVAL;
1899 return 0;
1900 }
release_user_cpus_ptr(struct task_struct * p)1901 static inline void release_user_cpus_ptr(struct task_struct *p)
1902 {
1903 WARN_ON(p->user_cpus_ptr);
1904 }
1905
dl_task_check_affinity(struct task_struct * p,const struct cpumask * mask)1906 static inline int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask)
1907 {
1908 return 0;
1909 }
1910 #endif
1911
1912 extern int yield_to(struct task_struct *p, bool preempt);
1913 extern void set_user_nice(struct task_struct *p, long nice);
1914 extern int task_prio(const struct task_struct *p);
1915
1916 /**
1917 * task_nice - return the nice value of a given task.
1918 * @p: the task in question.
1919 *
1920 * Return: The nice value [ -20 ... 0 ... 19 ].
1921 */
task_nice(const struct task_struct * p)1922 static inline int task_nice(const struct task_struct *p)
1923 {
1924 return PRIO_TO_NICE((p)->static_prio);
1925 }
1926
1927 extern int can_nice(const struct task_struct *p, const int nice);
1928 extern int task_curr(const struct task_struct *p);
1929 extern int idle_cpu(int cpu);
1930 extern int available_idle_cpu(int cpu);
1931 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *);
1932 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *);
1933 extern void sched_set_fifo(struct task_struct *p);
1934 extern void sched_set_fifo_low(struct task_struct *p);
1935 extern void sched_set_normal(struct task_struct *p, int nice);
1936 extern int sched_setattr(struct task_struct *, const struct sched_attr *);
1937 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *);
1938 extern struct task_struct *idle_task(int cpu);
1939
1940 /**
1941 * is_idle_task - is the specified task an idle task?
1942 * @p: the task in question.
1943 *
1944 * Return: 1 if @p is an idle task. 0 otherwise.
1945 */
is_idle_task(const struct task_struct * p)1946 static __always_inline bool is_idle_task(const struct task_struct *p)
1947 {
1948 return !!(p->flags & PF_IDLE);
1949 }
1950
1951 extern struct task_struct *curr_task(int cpu);
1952 extern void ia64_set_curr_task(int cpu, struct task_struct *p);
1953
1954 void yield(void);
1955
1956 union thread_union {
1957 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK
1958 struct task_struct task;
1959 #endif
1960 #ifndef CONFIG_THREAD_INFO_IN_TASK
1961 struct thread_info thread_info;
1962 #endif
1963 unsigned long stack[THREAD_SIZE/sizeof(long)];
1964 };
1965
1966 #ifndef CONFIG_THREAD_INFO_IN_TASK
1967 extern struct thread_info init_thread_info;
1968 #endif
1969
1970 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
1971
1972 #ifdef CONFIG_THREAD_INFO_IN_TASK
1973 # define task_thread_info(task) (&(task)->thread_info)
1974 #elif !defined(__HAVE_THREAD_FUNCTIONS)
1975 # define task_thread_info(task) ((struct thread_info *)(task)->stack)
1976 #endif
1977
1978 /*
1979 * find a task by one of its numerical ids
1980 *
1981 * find_task_by_pid_ns():
1982 * finds a task by its pid in the specified namespace
1983 * find_task_by_vpid():
1984 * finds a task by its virtual pid
1985 *
1986 * see also find_vpid() etc in include/linux/pid.h
1987 */
1988
1989 extern struct task_struct *find_task_by_vpid(pid_t nr);
1990 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns);
1991
1992 /*
1993 * find a task by its virtual pid and get the task struct
1994 */
1995 extern struct task_struct *find_get_task_by_vpid(pid_t nr);
1996
1997 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
1998 extern int wake_up_process(struct task_struct *tsk);
1999 extern void wake_up_new_task(struct task_struct *tsk);
2000
2001 #ifdef CONFIG_SMP
2002 extern void kick_process(struct task_struct *tsk);
2003 #else
kick_process(struct task_struct * tsk)2004 static inline void kick_process(struct task_struct *tsk) { }
2005 #endif
2006
2007 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
2008
set_task_comm(struct task_struct * tsk,const char * from)2009 static inline void set_task_comm(struct task_struct *tsk, const char *from)
2010 {
2011 __set_task_comm(tsk, from, false);
2012 }
2013
2014 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk);
2015 #define get_task_comm(buf, tsk) ({ \
2016 BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN); \
2017 __get_task_comm(buf, sizeof(buf), tsk); \
2018 })
2019
2020 #ifdef CONFIG_SMP
scheduler_ipi(void)2021 static __always_inline void scheduler_ipi(void)
2022 {
2023 /*
2024 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting
2025 * TIF_NEED_RESCHED remotely (for the first time) will also send
2026 * this IPI.
2027 */
2028 preempt_fold_need_resched();
2029 }
2030 #else
scheduler_ipi(void)2031 static inline void scheduler_ipi(void) { }
2032 #endif
2033
2034 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state);
2035
2036 /*
2037 * Set thread flags in other task's structures.
2038 * See asm/thread_info.h for TIF_xxxx flags available:
2039 */
set_tsk_thread_flag(struct task_struct * tsk,int flag)2040 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2041 {
2042 set_ti_thread_flag(task_thread_info(tsk), flag);
2043 }
2044
clear_tsk_thread_flag(struct task_struct * tsk,int flag)2045 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2046 {
2047 clear_ti_thread_flag(task_thread_info(tsk), flag);
2048 }
2049
update_tsk_thread_flag(struct task_struct * tsk,int flag,bool value)2050 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag,
2051 bool value)
2052 {
2053 update_ti_thread_flag(task_thread_info(tsk), flag, value);
2054 }
2055
test_and_set_tsk_thread_flag(struct task_struct * tsk,int flag)2056 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2057 {
2058 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2059 }
2060
test_and_clear_tsk_thread_flag(struct task_struct * tsk,int flag)2061 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2062 {
2063 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2064 }
2065
test_tsk_thread_flag(struct task_struct * tsk,int flag)2066 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2067 {
2068 return test_ti_thread_flag(task_thread_info(tsk), flag);
2069 }
2070
set_tsk_need_resched(struct task_struct * tsk)2071 static inline void set_tsk_need_resched(struct task_struct *tsk)
2072 {
2073 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2074 }
2075
clear_tsk_need_resched(struct task_struct * tsk)2076 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2077 {
2078 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2079 }
2080
test_tsk_need_resched(struct task_struct * tsk)2081 static inline int test_tsk_need_resched(struct task_struct *tsk)
2082 {
2083 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2084 }
2085
2086 /*
2087 * cond_resched() and cond_resched_lock(): latency reduction via
2088 * explicit rescheduling in places that are safe. The return
2089 * value indicates whether a reschedule was done in fact.
2090 * cond_resched_lock() will drop the spinlock before scheduling,
2091 */
2092 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC)
2093 extern int __cond_resched(void);
2094
2095 #if defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL)
2096
2097 void sched_dynamic_klp_enable(void);
2098 void sched_dynamic_klp_disable(void);
2099
2100 DECLARE_STATIC_CALL(cond_resched, __cond_resched);
2101
_cond_resched(void)2102 static __always_inline int _cond_resched(void)
2103 {
2104 return static_call_mod(cond_resched)();
2105 }
2106
2107 #elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY)
2108
2109 extern int dynamic_cond_resched(void);
2110
_cond_resched(void)2111 static __always_inline int _cond_resched(void)
2112 {
2113 return dynamic_cond_resched();
2114 }
2115
2116 #else /* !CONFIG_PREEMPTION */
2117
_cond_resched(void)2118 static inline int _cond_resched(void)
2119 {
2120 klp_sched_try_switch();
2121 return __cond_resched();
2122 }
2123
2124 #endif /* PREEMPT_DYNAMIC && CONFIG_HAVE_PREEMPT_DYNAMIC_CALL */
2125
2126 #else /* CONFIG_PREEMPTION && !CONFIG_PREEMPT_DYNAMIC */
2127
_cond_resched(void)2128 static inline int _cond_resched(void)
2129 {
2130 klp_sched_try_switch();
2131 return 0;
2132 }
2133
2134 #endif /* !CONFIG_PREEMPTION || CONFIG_PREEMPT_DYNAMIC */
2135
2136 #define cond_resched() ({ \
2137 __might_resched(__FILE__, __LINE__, 0); \
2138 _cond_resched(); \
2139 })
2140
2141 extern int __cond_resched_lock(spinlock_t *lock);
2142 extern int __cond_resched_rwlock_read(rwlock_t *lock);
2143 extern int __cond_resched_rwlock_write(rwlock_t *lock);
2144
2145 #define MIGHT_RESCHED_RCU_SHIFT 8
2146 #define MIGHT_RESCHED_PREEMPT_MASK ((1U << MIGHT_RESCHED_RCU_SHIFT) - 1)
2147
2148 #ifndef CONFIG_PREEMPT_RT
2149 /*
2150 * Non RT kernels have an elevated preempt count due to the held lock,
2151 * but are not allowed to be inside a RCU read side critical section
2152 */
2153 # define PREEMPT_LOCK_RESCHED_OFFSETS PREEMPT_LOCK_OFFSET
2154 #else
2155 /*
2156 * spin/rw_lock() on RT implies rcu_read_lock(). The might_sleep() check in
2157 * cond_resched*lock() has to take that into account because it checks for
2158 * preempt_count() and rcu_preempt_depth().
2159 */
2160 # define PREEMPT_LOCK_RESCHED_OFFSETS \
2161 (PREEMPT_LOCK_OFFSET + (1U << MIGHT_RESCHED_RCU_SHIFT))
2162 #endif
2163
2164 #define cond_resched_lock(lock) ({ \
2165 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \
2166 __cond_resched_lock(lock); \
2167 })
2168
2169 #define cond_resched_rwlock_read(lock) ({ \
2170 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \
2171 __cond_resched_rwlock_read(lock); \
2172 })
2173
2174 #define cond_resched_rwlock_write(lock) ({ \
2175 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \
2176 __cond_resched_rwlock_write(lock); \
2177 })
2178
cond_resched_rcu(void)2179 static inline void cond_resched_rcu(void)
2180 {
2181 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
2182 rcu_read_unlock();
2183 cond_resched();
2184 rcu_read_lock();
2185 #endif
2186 }
2187
2188 #ifdef CONFIG_PREEMPT_DYNAMIC
2189
2190 extern bool preempt_model_none(void);
2191 extern bool preempt_model_voluntary(void);
2192 extern bool preempt_model_full(void);
2193
2194 #else
2195
preempt_model_none(void)2196 static inline bool preempt_model_none(void)
2197 {
2198 return IS_ENABLED(CONFIG_PREEMPT_NONE);
2199 }
preempt_model_voluntary(void)2200 static inline bool preempt_model_voluntary(void)
2201 {
2202 return IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY);
2203 }
preempt_model_full(void)2204 static inline bool preempt_model_full(void)
2205 {
2206 return IS_ENABLED(CONFIG_PREEMPT);
2207 }
2208
2209 #endif
2210
preempt_model_rt(void)2211 static inline bool preempt_model_rt(void)
2212 {
2213 return IS_ENABLED(CONFIG_PREEMPT_RT);
2214 }
2215
2216 /*
2217 * Does the preemption model allow non-cooperative preemption?
2218 *
2219 * For !CONFIG_PREEMPT_DYNAMIC kernels this is an exact match with
2220 * CONFIG_PREEMPTION; for CONFIG_PREEMPT_DYNAMIC this doesn't work as the
2221 * kernel is *built* with CONFIG_PREEMPTION=y but may run with e.g. the
2222 * PREEMPT_NONE model.
2223 */
preempt_model_preemptible(void)2224 static inline bool preempt_model_preemptible(void)
2225 {
2226 return preempt_model_full() || preempt_model_rt();
2227 }
2228
2229 /*
2230 * Does a critical section need to be broken due to another
2231 * task waiting?: (technically does not depend on CONFIG_PREEMPTION,
2232 * but a general need for low latency)
2233 */
spin_needbreak(spinlock_t * lock)2234 static inline int spin_needbreak(spinlock_t *lock)
2235 {
2236 #ifdef CONFIG_PREEMPTION
2237 return spin_is_contended(lock);
2238 #else
2239 return 0;
2240 #endif
2241 }
2242
2243 /*
2244 * Check if a rwlock is contended.
2245 * Returns non-zero if there is another task waiting on the rwlock.
2246 * Returns zero if the lock is not contended or the system / underlying
2247 * rwlock implementation does not support contention detection.
2248 * Technically does not depend on CONFIG_PREEMPTION, but a general need
2249 * for low latency.
2250 */
rwlock_needbreak(rwlock_t * lock)2251 static inline int rwlock_needbreak(rwlock_t *lock)
2252 {
2253 #ifdef CONFIG_PREEMPTION
2254 return rwlock_is_contended(lock);
2255 #else
2256 return 0;
2257 #endif
2258 }
2259
need_resched(void)2260 static __always_inline bool need_resched(void)
2261 {
2262 return unlikely(tif_need_resched());
2263 }
2264
2265 /*
2266 * Wrappers for p->thread_info->cpu access. No-op on UP.
2267 */
2268 #ifdef CONFIG_SMP
2269
task_cpu(const struct task_struct * p)2270 static inline unsigned int task_cpu(const struct task_struct *p)
2271 {
2272 return READ_ONCE(task_thread_info(p)->cpu);
2273 }
2274
2275 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2276
2277 #else
2278
task_cpu(const struct task_struct * p)2279 static inline unsigned int task_cpu(const struct task_struct *p)
2280 {
2281 return 0;
2282 }
2283
set_task_cpu(struct task_struct * p,unsigned int cpu)2284 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2285 {
2286 }
2287
2288 #endif /* CONFIG_SMP */
2289
2290 extern bool sched_task_on_rq(struct task_struct *p);
2291 extern unsigned long get_wchan(struct task_struct *p);
2292 extern struct task_struct *cpu_curr_snapshot(int cpu);
2293
2294 /*
2295 * In order to reduce various lock holder preemption latencies provide an
2296 * interface to see if a vCPU is currently running or not.
2297 *
2298 * This allows us to terminate optimistic spin loops and block, analogous to
2299 * the native optimistic spin heuristic of testing if the lock owner task is
2300 * running or not.
2301 */
2302 #ifndef vcpu_is_preempted
vcpu_is_preempted(int cpu)2303 static inline bool vcpu_is_preempted(int cpu)
2304 {
2305 return false;
2306 }
2307 #endif
2308
2309 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2310 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2311
2312 #ifndef TASK_SIZE_OF
2313 #define TASK_SIZE_OF(tsk) TASK_SIZE
2314 #endif
2315
2316 #ifdef CONFIG_SMP
owner_on_cpu(struct task_struct * owner)2317 static inline bool owner_on_cpu(struct task_struct *owner)
2318 {
2319 /*
2320 * As lock holder preemption issue, we both skip spinning if
2321 * task is not on cpu or its cpu is preempted
2322 */
2323 return READ_ONCE(owner->on_cpu) && !vcpu_is_preempted(task_cpu(owner));
2324 }
2325
2326 /* Returns effective CPU energy utilization, as seen by the scheduler */
2327 unsigned long sched_cpu_util(int cpu);
2328 #endif /* CONFIG_SMP */
2329
2330 #ifdef CONFIG_RSEQ
2331
2332 /*
2333 * Map the event mask on the user-space ABI enum rseq_cs_flags
2334 * for direct mask checks.
2335 */
2336 enum rseq_event_mask_bits {
2337 RSEQ_EVENT_PREEMPT_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT,
2338 RSEQ_EVENT_SIGNAL_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT,
2339 RSEQ_EVENT_MIGRATE_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT,
2340 };
2341
2342 enum rseq_event_mask {
2343 RSEQ_EVENT_PREEMPT = (1U << RSEQ_EVENT_PREEMPT_BIT),
2344 RSEQ_EVENT_SIGNAL = (1U << RSEQ_EVENT_SIGNAL_BIT),
2345 RSEQ_EVENT_MIGRATE = (1U << RSEQ_EVENT_MIGRATE_BIT),
2346 };
2347
rseq_set_notify_resume(struct task_struct * t)2348 static inline void rseq_set_notify_resume(struct task_struct *t)
2349 {
2350 if (t->rseq)
2351 set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
2352 }
2353
2354 void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs);
2355
rseq_handle_notify_resume(struct ksignal * ksig,struct pt_regs * regs)2356 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
2357 struct pt_regs *regs)
2358 {
2359 if (current->rseq)
2360 __rseq_handle_notify_resume(ksig, regs);
2361 }
2362
rseq_signal_deliver(struct ksignal * ksig,struct pt_regs * regs)2363 static inline void rseq_signal_deliver(struct ksignal *ksig,
2364 struct pt_regs *regs)
2365 {
2366 preempt_disable();
2367 __set_bit(RSEQ_EVENT_SIGNAL_BIT, ¤t->rseq_event_mask);
2368 preempt_enable();
2369 rseq_handle_notify_resume(ksig, regs);
2370 }
2371
2372 /* rseq_preempt() requires preemption to be disabled. */
rseq_preempt(struct task_struct * t)2373 static inline void rseq_preempt(struct task_struct *t)
2374 {
2375 __set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask);
2376 rseq_set_notify_resume(t);
2377 }
2378
2379 /* rseq_migrate() requires preemption to be disabled. */
rseq_migrate(struct task_struct * t)2380 static inline void rseq_migrate(struct task_struct *t)
2381 {
2382 __set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask);
2383 rseq_set_notify_resume(t);
2384 }
2385
2386 /*
2387 * If parent process has a registered restartable sequences area, the
2388 * child inherits. Unregister rseq for a clone with CLONE_VM set.
2389 */
rseq_fork(struct task_struct * t,unsigned long clone_flags)2390 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
2391 {
2392 if (clone_flags & CLONE_VM) {
2393 t->rseq = NULL;
2394 t->rseq_len = 0;
2395 t->rseq_sig = 0;
2396 t->rseq_event_mask = 0;
2397 } else {
2398 t->rseq = current->rseq;
2399 t->rseq_len = current->rseq_len;
2400 t->rseq_sig = current->rseq_sig;
2401 t->rseq_event_mask = current->rseq_event_mask;
2402 }
2403 }
2404
rseq_execve(struct task_struct * t)2405 static inline void rseq_execve(struct task_struct *t)
2406 {
2407 t->rseq = NULL;
2408 t->rseq_len = 0;
2409 t->rseq_sig = 0;
2410 t->rseq_event_mask = 0;
2411 }
2412
2413 #else
2414
rseq_set_notify_resume(struct task_struct * t)2415 static inline void rseq_set_notify_resume(struct task_struct *t)
2416 {
2417 }
rseq_handle_notify_resume(struct ksignal * ksig,struct pt_regs * regs)2418 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
2419 struct pt_regs *regs)
2420 {
2421 }
rseq_signal_deliver(struct ksignal * ksig,struct pt_regs * regs)2422 static inline void rseq_signal_deliver(struct ksignal *ksig,
2423 struct pt_regs *regs)
2424 {
2425 }
rseq_preempt(struct task_struct * t)2426 static inline void rseq_preempt(struct task_struct *t)
2427 {
2428 }
rseq_migrate(struct task_struct * t)2429 static inline void rseq_migrate(struct task_struct *t)
2430 {
2431 }
rseq_fork(struct task_struct * t,unsigned long clone_flags)2432 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
2433 {
2434 }
rseq_execve(struct task_struct * t)2435 static inline void rseq_execve(struct task_struct *t)
2436 {
2437 }
2438
2439 #endif
2440
2441 #ifdef CONFIG_DEBUG_RSEQ
2442
2443 void rseq_syscall(struct pt_regs *regs);
2444
2445 #else
2446
rseq_syscall(struct pt_regs * regs)2447 static inline void rseq_syscall(struct pt_regs *regs)
2448 {
2449 }
2450
2451 #endif
2452
2453 #ifdef CONFIG_SCHED_CORE
2454 extern void sched_core_free(struct task_struct *tsk);
2455 extern void sched_core_fork(struct task_struct *p);
2456 extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type,
2457 unsigned long uaddr);
2458 extern int sched_core_idle_cpu(int cpu);
2459 #else
sched_core_free(struct task_struct * tsk)2460 static inline void sched_core_free(struct task_struct *tsk) { }
sched_core_fork(struct task_struct * p)2461 static inline void sched_core_fork(struct task_struct *p) { }
sched_core_idle_cpu(int cpu)2462 static inline int sched_core_idle_cpu(int cpu) { return idle_cpu(cpu); }
2463 #endif
2464
2465 extern void sched_set_stop_task(int cpu, struct task_struct *stop);
2466
2467 #endif
2468