1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_SCHED_H
3 #define _LINUX_SCHED_H
4
5 /*
6 * Define 'struct task_struct' and provide the main scheduler
7 * APIs (schedule(), wakeup variants, etc.)
8 */
9
10 #include <uapi/linux/sched.h>
11
12 #include <asm/current.h>
13 #include <asm/processor.h>
14 #include <linux/thread_info.h>
15 #include <linux/preempt.h>
16 #include <linux/cpumask_types.h>
17
18 #include <linux/cache.h>
19 #include <linux/irqflags_types.h>
20 #include <linux/smp_types.h>
21 #include <linux/pid_types.h>
22 #include <linux/sem_types.h>
23 #include <linux/shm.h>
24 #include <linux/kmsan_types.h>
25 #include <linux/mutex_types.h>
26 #include <linux/plist_types.h>
27 #include <linux/hrtimer_types.h>
28 #include <linux/timer_types.h>
29 #include <linux/seccomp_types.h>
30 #include <linux/nodemask_types.h>
31 #include <linux/refcount_types.h>
32 #include <linux/resource.h>
33 #include <linux/latencytop.h>
34 #include <linux/sched/prio.h>
35 #include <linux/sched/types.h>
36 #include <linux/signal_types.h>
37 #include <linux/spinlock.h>
38 #include <linux/syscall_user_dispatch_types.h>
39 #include <linux/mm_types_task.h>
40 #include <linux/netdevice_xmit.h>
41 #include <linux/task_io_accounting.h>
42 #include <linux/posix-timers_types.h>
43 #include <linux/restart_block.h>
44 #include <uapi/linux/rseq.h>
45 #include <linux/seqlock_types.h>
46 #include <linux/kcsan.h>
47 #include <linux/rv.h>
48 #include <linux/uidgid_types.h>
49 #include <linux/tracepoint-defs.h>
50 #include <linux/unwind_deferred_types.h>
51 #include <asm/kmap_size.h>
52
53 /* task_struct member predeclarations (sorted alphabetically): */
54 struct audit_context;
55 struct bio_list;
56 struct blk_plug;
57 struct bpf_local_storage;
58 struct bpf_run_ctx;
59 struct bpf_net_context;
60 struct capture_control;
61 struct cfs_rq;
62 struct fs_struct;
63 struct futex_pi_state;
64 struct io_context;
65 struct io_uring_task;
66 struct mempolicy;
67 struct nameidata;
68 struct nsproxy;
69 struct perf_event_context;
70 struct perf_ctx_data;
71 struct pid_namespace;
72 struct pipe_inode_info;
73 struct rcu_node;
74 struct reclaim_state;
75 struct robust_list_head;
76 struct root_domain;
77 struct rq;
78 struct sched_attr;
79 struct sched_dl_entity;
80 struct seq_file;
81 struct sighand_struct;
82 struct signal_struct;
83 struct task_delay_info;
84 struct task_group;
85 struct task_struct;
86 struct user_event_mm;
87
88 #include <linux/sched/ext.h>
89
90 /*
91 * Task state bitmask. NOTE! These bits are also
92 * encoded in fs/proc/array.c: get_task_state().
93 *
94 * We have two separate sets of flags: task->__state
95 * is about runnability, while task->exit_state are
96 * about the task exiting. Confusing, but this way
97 * modifying one set can't modify the other one by
98 * mistake.
99 */
100
101 /* Used in tsk->__state: */
102 #define TASK_RUNNING 0x00000000
103 #define TASK_INTERRUPTIBLE 0x00000001
104 #define TASK_UNINTERRUPTIBLE 0x00000002
105 #define __TASK_STOPPED 0x00000004
106 #define __TASK_TRACED 0x00000008
107 /* Used in tsk->exit_state: */
108 #define EXIT_DEAD 0x00000010
109 #define EXIT_ZOMBIE 0x00000020
110 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD)
111 /* Used in tsk->__state again: */
112 #define TASK_PARKED 0x00000040
113 #define TASK_DEAD 0x00000080
114 #define TASK_WAKEKILL 0x00000100
115 #define TASK_WAKING 0x00000200
116 #define TASK_NOLOAD 0x00000400
117 #define TASK_NEW 0x00000800
118 #define TASK_RTLOCK_WAIT 0x00001000
119 #define TASK_FREEZABLE 0x00002000
120 #define __TASK_FREEZABLE_UNSAFE (0x00004000 * IS_ENABLED(CONFIG_LOCKDEP))
121 #define TASK_FROZEN 0x00008000
122 #define TASK_STATE_MAX 0x00010000
123
124 #define TASK_ANY (TASK_STATE_MAX-1)
125
126 /*
127 * DO NOT ADD ANY NEW USERS !
128 */
129 #define TASK_FREEZABLE_UNSAFE (TASK_FREEZABLE | __TASK_FREEZABLE_UNSAFE)
130
131 /* Convenience macros for the sake of set_current_state: */
132 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
133 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED)
134 #define TASK_TRACED __TASK_TRACED
135
136 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
137
138 /* Convenience macros for the sake of wake_up(): */
139 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
140
141 /* get_task_state(): */
142 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \
143 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
144 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
145 TASK_PARKED)
146
147 #define task_is_running(task) (READ_ONCE((task)->__state) == TASK_RUNNING)
148
149 #define task_is_traced(task) ((READ_ONCE(task->jobctl) & JOBCTL_TRACED) != 0)
150 #define task_is_stopped(task) ((READ_ONCE(task->jobctl) & JOBCTL_STOPPED) != 0)
151 #define task_is_stopped_or_traced(task) ((READ_ONCE(task->jobctl) & (JOBCTL_STOPPED | JOBCTL_TRACED)) != 0)
152
153 /*
154 * Special states are those that do not use the normal wait-loop pattern. See
155 * the comment with set_special_state().
156 */
157 #define is_special_task_state(state) \
158 ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | \
159 TASK_DEAD | TASK_FROZEN))
160
161 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
162 # define debug_normal_state_change(state_value) \
163 do { \
164 WARN_ON_ONCE(is_special_task_state(state_value)); \
165 current->task_state_change = _THIS_IP_; \
166 } while (0)
167
168 # define debug_special_state_change(state_value) \
169 do { \
170 WARN_ON_ONCE(!is_special_task_state(state_value)); \
171 current->task_state_change = _THIS_IP_; \
172 } while (0)
173
174 # define debug_rtlock_wait_set_state() \
175 do { \
176 current->saved_state_change = current->task_state_change;\
177 current->task_state_change = _THIS_IP_; \
178 } while (0)
179
180 # define debug_rtlock_wait_restore_state() \
181 do { \
182 current->task_state_change = current->saved_state_change;\
183 } while (0)
184
185 #else
186 # define debug_normal_state_change(cond) do { } while (0)
187 # define debug_special_state_change(cond) do { } while (0)
188 # define debug_rtlock_wait_set_state() do { } while (0)
189 # define debug_rtlock_wait_restore_state() do { } while (0)
190 #endif
191
192 #define trace_set_current_state(state_value) \
193 do { \
194 if (tracepoint_enabled(sched_set_state_tp)) \
195 __trace_set_current_state(state_value); \
196 } while (0)
197
198 /*
199 * set_current_state() includes a barrier so that the write of current->__state
200 * is correctly serialised wrt the caller's subsequent test of whether to
201 * actually sleep:
202 *
203 * for (;;) {
204 * set_current_state(TASK_UNINTERRUPTIBLE);
205 * if (CONDITION)
206 * break;
207 *
208 * schedule();
209 * }
210 * __set_current_state(TASK_RUNNING);
211 *
212 * If the caller does not need such serialisation (because, for instance, the
213 * CONDITION test and condition change and wakeup are under the same lock) then
214 * use __set_current_state().
215 *
216 * The above is typically ordered against the wakeup, which does:
217 *
218 * CONDITION = 1;
219 * wake_up_state(p, TASK_UNINTERRUPTIBLE);
220 *
221 * where wake_up_state()/try_to_wake_up() executes a full memory barrier before
222 * accessing p->__state.
223 *
224 * Wakeup will do: if (@state & p->__state) p->__state = TASK_RUNNING, that is,
225 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
226 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
227 *
228 * However, with slightly different timing the wakeup TASK_RUNNING store can
229 * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not
230 * a problem either because that will result in one extra go around the loop
231 * and our @cond test will save the day.
232 *
233 * Also see the comments of try_to_wake_up().
234 */
235 #define __set_current_state(state_value) \
236 do { \
237 debug_normal_state_change((state_value)); \
238 trace_set_current_state(state_value); \
239 WRITE_ONCE(current->__state, (state_value)); \
240 } while (0)
241
242 #define set_current_state(state_value) \
243 do { \
244 debug_normal_state_change((state_value)); \
245 trace_set_current_state(state_value); \
246 smp_store_mb(current->__state, (state_value)); \
247 } while (0)
248
249 /*
250 * set_special_state() should be used for those states when the blocking task
251 * can not use the regular condition based wait-loop. In that case we must
252 * serialize against wakeups such that any possible in-flight TASK_RUNNING
253 * stores will not collide with our state change.
254 */
255 #define set_special_state(state_value) \
256 do { \
257 unsigned long flags; /* may shadow */ \
258 \
259 raw_spin_lock_irqsave(¤t->pi_lock, flags); \
260 debug_special_state_change((state_value)); \
261 trace_set_current_state(state_value); \
262 WRITE_ONCE(current->__state, (state_value)); \
263 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \
264 } while (0)
265
266 /*
267 * PREEMPT_RT specific variants for "sleeping" spin/rwlocks
268 *
269 * RT's spin/rwlock substitutions are state preserving. The state of the
270 * task when blocking on the lock is saved in task_struct::saved_state and
271 * restored after the lock has been acquired. These operations are
272 * serialized by task_struct::pi_lock against try_to_wake_up(). Any non RT
273 * lock related wakeups while the task is blocked on the lock are
274 * redirected to operate on task_struct::saved_state to ensure that these
275 * are not dropped. On restore task_struct::saved_state is set to
276 * TASK_RUNNING so any wakeup attempt redirected to saved_state will fail.
277 *
278 * The lock operation looks like this:
279 *
280 * current_save_and_set_rtlock_wait_state();
281 * for (;;) {
282 * if (try_lock())
283 * break;
284 * raw_spin_unlock_irq(&lock->wait_lock);
285 * schedule_rtlock();
286 * raw_spin_lock_irq(&lock->wait_lock);
287 * set_current_state(TASK_RTLOCK_WAIT);
288 * }
289 * current_restore_rtlock_saved_state();
290 */
291 #define current_save_and_set_rtlock_wait_state() \
292 do { \
293 lockdep_assert_irqs_disabled(); \
294 raw_spin_lock(¤t->pi_lock); \
295 current->saved_state = current->__state; \
296 debug_rtlock_wait_set_state(); \
297 trace_set_current_state(TASK_RTLOCK_WAIT); \
298 WRITE_ONCE(current->__state, TASK_RTLOCK_WAIT); \
299 raw_spin_unlock(¤t->pi_lock); \
300 } while (0);
301
302 #define current_restore_rtlock_saved_state() \
303 do { \
304 lockdep_assert_irqs_disabled(); \
305 raw_spin_lock(¤t->pi_lock); \
306 debug_rtlock_wait_restore_state(); \
307 trace_set_current_state(current->saved_state); \
308 WRITE_ONCE(current->__state, current->saved_state); \
309 current->saved_state = TASK_RUNNING; \
310 raw_spin_unlock(¤t->pi_lock); \
311 } while (0);
312
313 #define get_current_state() READ_ONCE(current->__state)
314
315 /*
316 * Define the task command name length as enum, then it can be visible to
317 * BPF programs.
318 */
319 enum {
320 TASK_COMM_LEN = 16,
321 };
322
323 extern void sched_tick(void);
324
325 #define MAX_SCHEDULE_TIMEOUT LONG_MAX
326
327 extern long schedule_timeout(long timeout);
328 extern long schedule_timeout_interruptible(long timeout);
329 extern long schedule_timeout_killable(long timeout);
330 extern long schedule_timeout_uninterruptible(long timeout);
331 extern long schedule_timeout_idle(long timeout);
332 asmlinkage void schedule(void);
333 extern void schedule_preempt_disabled(void);
334 asmlinkage void preempt_schedule_irq(void);
335 #ifdef CONFIG_PREEMPT_RT
336 extern void schedule_rtlock(void);
337 #endif
338
339 extern int __must_check io_schedule_prepare(void);
340 extern void io_schedule_finish(int token);
341 extern long io_schedule_timeout(long timeout);
342 extern void io_schedule(void);
343
344 /* wrapper functions to trace from this header file */
345 DECLARE_TRACEPOINT(sched_set_state_tp);
346 extern void __trace_set_current_state(int state_value);
347 DECLARE_TRACEPOINT(sched_set_need_resched_tp);
348 extern void __trace_set_need_resched(struct task_struct *curr, int tif);
349
350 /**
351 * struct prev_cputime - snapshot of system and user cputime
352 * @utime: time spent in user mode
353 * @stime: time spent in system mode
354 * @lock: protects the above two fields
355 *
356 * Stores previous user/system time values such that we can guarantee
357 * monotonicity.
358 */
359 struct prev_cputime {
360 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
361 u64 utime;
362 u64 stime;
363 raw_spinlock_t lock;
364 #endif
365 };
366
367 enum vtime_state {
368 /* Task is sleeping or running in a CPU with VTIME inactive: */
369 VTIME_INACTIVE = 0,
370 /* Task is idle */
371 VTIME_IDLE,
372 /* Task runs in kernelspace in a CPU with VTIME active: */
373 VTIME_SYS,
374 /* Task runs in userspace in a CPU with VTIME active: */
375 VTIME_USER,
376 /* Task runs as guests in a CPU with VTIME active: */
377 VTIME_GUEST,
378 };
379
380 struct vtime {
381 seqcount_t seqcount;
382 unsigned long long starttime;
383 enum vtime_state state;
384 unsigned int cpu;
385 u64 utime;
386 u64 stime;
387 u64 gtime;
388 };
389
390 /*
391 * Utilization clamp constraints.
392 * @UCLAMP_MIN: Minimum utilization
393 * @UCLAMP_MAX: Maximum utilization
394 * @UCLAMP_CNT: Utilization clamp constraints count
395 */
396 enum uclamp_id {
397 UCLAMP_MIN = 0,
398 UCLAMP_MAX,
399 UCLAMP_CNT
400 };
401
402 extern struct root_domain def_root_domain;
403 extern struct mutex sched_domains_mutex;
404 extern void sched_domains_mutex_lock(void);
405 extern void sched_domains_mutex_unlock(void);
406
407 struct sched_param {
408 int sched_priority;
409 };
410
411 struct sched_info {
412 #ifdef CONFIG_SCHED_INFO
413 /* Cumulative counters: */
414
415 /* # of times we have run on this CPU: */
416 unsigned long pcount;
417
418 /* Time spent waiting on a runqueue: */
419 unsigned long long run_delay;
420
421 /* Max time spent waiting on a runqueue: */
422 unsigned long long max_run_delay;
423
424 /* Min time spent waiting on a runqueue: */
425 unsigned long long min_run_delay;
426
427 /* Timestamps: */
428
429 /* When did we last run on a CPU? */
430 unsigned long long last_arrival;
431
432 /* When were we last queued to run? */
433 unsigned long long last_queued;
434
435 #endif /* CONFIG_SCHED_INFO */
436 };
437
438 /*
439 * Integer metrics need fixed point arithmetic, e.g., sched/fair
440 * has a few: load, load_avg, util_avg, freq, and capacity.
441 *
442 * We define a basic fixed point arithmetic range, and then formalize
443 * all these metrics based on that basic range.
444 */
445 # define SCHED_FIXEDPOINT_SHIFT 10
446 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT)
447
448 /* Increase resolution of cpu_capacity calculations */
449 # define SCHED_CAPACITY_SHIFT SCHED_FIXEDPOINT_SHIFT
450 # define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT)
451
452 struct load_weight {
453 unsigned long weight;
454 u32 inv_weight;
455 };
456
457 /*
458 * The load/runnable/util_avg accumulates an infinite geometric series
459 * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c).
460 *
461 * [load_avg definition]
462 *
463 * load_avg = runnable% * scale_load_down(load)
464 *
465 * [runnable_avg definition]
466 *
467 * runnable_avg = runnable% * SCHED_CAPACITY_SCALE
468 *
469 * [util_avg definition]
470 *
471 * util_avg = running% * SCHED_CAPACITY_SCALE
472 *
473 * where runnable% is the time ratio that a sched_entity is runnable and
474 * running% the time ratio that a sched_entity is running.
475 *
476 * For cfs_rq, they are the aggregated values of all runnable and blocked
477 * sched_entities.
478 *
479 * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU
480 * capacity scaling. The scaling is done through the rq_clock_pelt that is used
481 * for computing those signals (see update_rq_clock_pelt())
482 *
483 * N.B., the above ratios (runnable% and running%) themselves are in the
484 * range of [0, 1]. To do fixed point arithmetics, we therefore scale them
485 * to as large a range as necessary. This is for example reflected by
486 * util_avg's SCHED_CAPACITY_SCALE.
487 *
488 * [Overflow issue]
489 *
490 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
491 * with the highest load (=88761), always runnable on a single cfs_rq,
492 * and should not overflow as the number already hits PID_MAX_LIMIT.
493 *
494 * For all other cases (including 32-bit kernels), struct load_weight's
495 * weight will overflow first before we do, because:
496 *
497 * Max(load_avg) <= Max(load.weight)
498 *
499 * Then it is the load_weight's responsibility to consider overflow
500 * issues.
501 */
502 struct sched_avg {
503 u64 last_update_time;
504 u64 load_sum;
505 u64 runnable_sum;
506 u32 util_sum;
507 u32 period_contrib;
508 unsigned long load_avg;
509 unsigned long runnable_avg;
510 unsigned long util_avg;
511 unsigned int util_est;
512 } ____cacheline_aligned;
513
514 /*
515 * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg
516 * updates. When a task is dequeued, its util_est should not be updated if its
517 * util_avg has not been updated in the meantime.
518 * This information is mapped into the MSB bit of util_est at dequeue time.
519 * Since max value of util_est for a task is 1024 (PELT util_avg for a task)
520 * it is safe to use MSB.
521 */
522 #define UTIL_EST_WEIGHT_SHIFT 2
523 #define UTIL_AVG_UNCHANGED 0x80000000
524
525 struct sched_statistics {
526 #ifdef CONFIG_SCHEDSTATS
527 u64 wait_start;
528 u64 wait_max;
529 u64 wait_count;
530 u64 wait_sum;
531 u64 iowait_count;
532 u64 iowait_sum;
533
534 u64 sleep_start;
535 u64 sleep_max;
536 s64 sum_sleep_runtime;
537
538 u64 block_start;
539 u64 block_max;
540 s64 sum_block_runtime;
541
542 s64 exec_max;
543 u64 slice_max;
544
545 u64 nr_migrations_cold;
546 u64 nr_failed_migrations_affine;
547 u64 nr_failed_migrations_running;
548 u64 nr_failed_migrations_hot;
549 u64 nr_forced_migrations;
550
551 u64 nr_wakeups;
552 u64 nr_wakeups_sync;
553 u64 nr_wakeups_migrate;
554 u64 nr_wakeups_local;
555 u64 nr_wakeups_remote;
556 u64 nr_wakeups_affine;
557 u64 nr_wakeups_affine_attempts;
558 u64 nr_wakeups_passive;
559 u64 nr_wakeups_idle;
560
561 #ifdef CONFIG_SCHED_CORE
562 u64 core_forceidle_sum;
563 #endif
564 #endif /* CONFIG_SCHEDSTATS */
565 } ____cacheline_aligned;
566
567 struct sched_entity {
568 /* For load-balancing: */
569 struct load_weight load;
570 struct rb_node run_node;
571 u64 deadline;
572 u64 min_vruntime;
573 u64 min_slice;
574
575 struct list_head group_node;
576 unsigned char on_rq;
577 unsigned char sched_delayed;
578 unsigned char rel_deadline;
579 unsigned char custom_slice;
580 /* hole */
581
582 u64 exec_start;
583 u64 sum_exec_runtime;
584 u64 prev_sum_exec_runtime;
585 u64 vruntime;
586 union {
587 /*
588 * When !@on_rq this field is vlag.
589 * When cfs_rq->curr == se (which implies @on_rq)
590 * this field is vprot. See protect_slice().
591 */
592 s64 vlag;
593 u64 vprot;
594 };
595 u64 slice;
596
597 u64 nr_migrations;
598
599 #ifdef CONFIG_FAIR_GROUP_SCHED
600 int depth;
601 struct sched_entity *parent;
602 /* rq on which this entity is (to be) queued: */
603 struct cfs_rq *cfs_rq;
604 /* rq "owned" by this entity/group: */
605 struct cfs_rq *my_q;
606 /* cached value of my_q->h_nr_running */
607 unsigned long runnable_weight;
608 #endif
609
610 /*
611 * Per entity load average tracking.
612 *
613 * Put into separate cache line so it does not
614 * collide with read-mostly values above.
615 */
616 struct sched_avg avg;
617 };
618
619 struct sched_rt_entity {
620 struct list_head run_list;
621 unsigned long timeout;
622 unsigned long watchdog_stamp;
623 unsigned int time_slice;
624 unsigned short on_rq;
625 unsigned short on_list;
626
627 struct sched_rt_entity *back;
628 #ifdef CONFIG_RT_GROUP_SCHED
629 struct sched_rt_entity *parent;
630 /* rq on which this entity is (to be) queued: */
631 struct rt_rq *rt_rq;
632 /* rq "owned" by this entity/group: */
633 struct rt_rq *my_q;
634 #endif
635 } __randomize_layout;
636
637 typedef bool (*dl_server_has_tasks_f)(struct sched_dl_entity *);
638 typedef struct task_struct *(*dl_server_pick_f)(struct sched_dl_entity *);
639
640 struct sched_dl_entity {
641 struct rb_node rb_node;
642
643 /*
644 * Original scheduling parameters. Copied here from sched_attr
645 * during sched_setattr(), they will remain the same until
646 * the next sched_setattr().
647 */
648 u64 dl_runtime; /* Maximum runtime for each instance */
649 u64 dl_deadline; /* Relative deadline of each instance */
650 u64 dl_period; /* Separation of two instances (period) */
651 u64 dl_bw; /* dl_runtime / dl_period */
652 u64 dl_density; /* dl_runtime / dl_deadline */
653
654 /*
655 * Actual scheduling parameters. Initialized with the values above,
656 * they are continuously updated during task execution. Note that
657 * the remaining runtime could be < 0 in case we are in overrun.
658 */
659 s64 runtime; /* Remaining runtime for this instance */
660 u64 deadline; /* Absolute deadline for this instance */
661 unsigned int flags; /* Specifying the scheduler behaviour */
662
663 /*
664 * Some bool flags:
665 *
666 * @dl_throttled tells if we exhausted the runtime. If so, the
667 * task has to wait for a replenishment to be performed at the
668 * next firing of dl_timer.
669 *
670 * @dl_yielded tells if task gave up the CPU before consuming
671 * all its available runtime during the last job.
672 *
673 * @dl_non_contending tells if the task is inactive while still
674 * contributing to the active utilization. In other words, it
675 * indicates if the inactive timer has been armed and its handler
676 * has not been executed yet. This flag is useful to avoid race
677 * conditions between the inactive timer handler and the wakeup
678 * code.
679 *
680 * @dl_overrun tells if the task asked to be informed about runtime
681 * overruns.
682 *
683 * @dl_server tells if this is a server entity.
684 *
685 * @dl_defer tells if this is a deferred or regular server. For
686 * now only defer server exists.
687 *
688 * @dl_defer_armed tells if the deferrable server is waiting
689 * for the replenishment timer to activate it.
690 *
691 * @dl_server_active tells if the dlserver is active(started).
692 * dlserver is started on first cfs enqueue on an idle runqueue
693 * and is stopped when a dequeue results in 0 cfs tasks on the
694 * runqueue. In other words, dlserver is active only when cpu's
695 * runqueue has atleast one cfs task.
696 *
697 * @dl_defer_running tells if the deferrable server is actually
698 * running, skipping the defer phase.
699 */
700 unsigned int dl_throttled : 1;
701 unsigned int dl_yielded : 1;
702 unsigned int dl_non_contending : 1;
703 unsigned int dl_overrun : 1;
704 unsigned int dl_server : 1;
705 unsigned int dl_server_active : 1;
706 unsigned int dl_defer : 1;
707 unsigned int dl_defer_armed : 1;
708 unsigned int dl_defer_running : 1;
709 unsigned int dl_server_idle : 1;
710
711 /*
712 * Bandwidth enforcement timer. Each -deadline task has its
713 * own bandwidth to be enforced, thus we need one timer per task.
714 */
715 struct hrtimer dl_timer;
716
717 /*
718 * Inactive timer, responsible for decreasing the active utilization
719 * at the "0-lag time". When a -deadline task blocks, it contributes
720 * to GRUB's active utilization until the "0-lag time", hence a
721 * timer is needed to decrease the active utilization at the correct
722 * time.
723 */
724 struct hrtimer inactive_timer;
725
726 /*
727 * Bits for DL-server functionality. Also see the comment near
728 * dl_server_update().
729 *
730 * @rq the runqueue this server is for
731 *
732 * @server_has_tasks() returns true if @server_pick return a
733 * runnable task.
734 */
735 struct rq *rq;
736 dl_server_has_tasks_f server_has_tasks;
737 dl_server_pick_f server_pick_task;
738
739 #ifdef CONFIG_RT_MUTEXES
740 /*
741 * Priority Inheritance. When a DEADLINE scheduling entity is boosted
742 * pi_se points to the donor, otherwise points to the dl_se it belongs
743 * to (the original one/itself).
744 */
745 struct sched_dl_entity *pi_se;
746 #endif
747 };
748
749 #ifdef CONFIG_UCLAMP_TASK
750 /* Number of utilization clamp buckets (shorter alias) */
751 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT
752
753 /*
754 * Utilization clamp for a scheduling entity
755 * @value: clamp value "assigned" to a se
756 * @bucket_id: bucket index corresponding to the "assigned" value
757 * @active: the se is currently refcounted in a rq's bucket
758 * @user_defined: the requested clamp value comes from user-space
759 *
760 * The bucket_id is the index of the clamp bucket matching the clamp value
761 * which is pre-computed and stored to avoid expensive integer divisions from
762 * the fast path.
763 *
764 * The active bit is set whenever a task has got an "effective" value assigned,
765 * which can be different from the clamp value "requested" from user-space.
766 * This allows to know a task is refcounted in the rq's bucket corresponding
767 * to the "effective" bucket_id.
768 *
769 * The user_defined bit is set whenever a task has got a task-specific clamp
770 * value requested from userspace, i.e. the system defaults apply to this task
771 * just as a restriction. This allows to relax default clamps when a less
772 * restrictive task-specific value has been requested, thus allowing to
773 * implement a "nice" semantic. For example, a task running with a 20%
774 * default boost can still drop its own boosting to 0%.
775 */
776 struct uclamp_se {
777 unsigned int value : bits_per(SCHED_CAPACITY_SCALE);
778 unsigned int bucket_id : bits_per(UCLAMP_BUCKETS);
779 unsigned int active : 1;
780 unsigned int user_defined : 1;
781 };
782 #endif /* CONFIG_UCLAMP_TASK */
783
784 union rcu_special {
785 struct {
786 u8 blocked;
787 u8 need_qs;
788 u8 exp_hint; /* Hint for performance. */
789 u8 need_mb; /* Readers need smp_mb(). */
790 } b; /* Bits. */
791 u32 s; /* Set of bits. */
792 };
793
794 enum perf_event_task_context {
795 perf_invalid_context = -1,
796 perf_hw_context = 0,
797 perf_sw_context,
798 perf_nr_task_contexts,
799 };
800
801 /*
802 * Number of contexts where an event can trigger:
803 * task, softirq, hardirq, nmi.
804 */
805 #define PERF_NR_CONTEXTS 4
806
807 struct wake_q_node {
808 struct wake_q_node *next;
809 };
810
811 struct kmap_ctrl {
812 #ifdef CONFIG_KMAP_LOCAL
813 int idx;
814 pte_t pteval[KM_MAX_IDX];
815 #endif
816 };
817
818 struct task_struct {
819 #ifdef CONFIG_THREAD_INFO_IN_TASK
820 /*
821 * For reasons of header soup (see current_thread_info()), this
822 * must be the first element of task_struct.
823 */
824 struct thread_info thread_info;
825 #endif
826 unsigned int __state;
827
828 /* saved state for "spinlock sleepers" */
829 unsigned int saved_state;
830
831 /*
832 * This begins the randomizable portion of task_struct. Only
833 * scheduling-critical items should be added above here.
834 */
835 randomized_struct_fields_start
836
837 void *stack;
838 refcount_t usage;
839 /* Per task flags (PF_*), defined further below: */
840 unsigned int flags;
841 unsigned int ptrace;
842
843 #ifdef CONFIG_MEM_ALLOC_PROFILING
844 struct alloc_tag *alloc_tag;
845 #endif
846
847 int on_cpu;
848 struct __call_single_node wake_entry;
849 unsigned int wakee_flips;
850 unsigned long wakee_flip_decay_ts;
851 struct task_struct *last_wakee;
852
853 /*
854 * recent_used_cpu is initially set as the last CPU used by a task
855 * that wakes affine another task. Waker/wakee relationships can
856 * push tasks around a CPU where each wakeup moves to the next one.
857 * Tracking a recently used CPU allows a quick search for a recently
858 * used CPU that may be idle.
859 */
860 int recent_used_cpu;
861 int wake_cpu;
862 int on_rq;
863
864 int prio;
865 int static_prio;
866 int normal_prio;
867 unsigned int rt_priority;
868
869 struct sched_entity se;
870 struct sched_rt_entity rt;
871 struct sched_dl_entity dl;
872 struct sched_dl_entity *dl_server;
873 #ifdef CONFIG_SCHED_CLASS_EXT
874 struct sched_ext_entity scx;
875 #endif
876 const struct sched_class *sched_class;
877
878 #ifdef CONFIG_SCHED_CORE
879 struct rb_node core_node;
880 unsigned long core_cookie;
881 unsigned int core_occupation;
882 #endif
883
884 #ifdef CONFIG_CGROUP_SCHED
885 struct task_group *sched_task_group;
886 #endif
887
888
889 #ifdef CONFIG_UCLAMP_TASK
890 /*
891 * Clamp values requested for a scheduling entity.
892 * Must be updated with task_rq_lock() held.
893 */
894 struct uclamp_se uclamp_req[UCLAMP_CNT];
895 /*
896 * Effective clamp values used for a scheduling entity.
897 * Must be updated with task_rq_lock() held.
898 */
899 struct uclamp_se uclamp[UCLAMP_CNT];
900 #endif
901
902 struct sched_statistics stats;
903
904 #ifdef CONFIG_PREEMPT_NOTIFIERS
905 /* List of struct preempt_notifier: */
906 struct hlist_head preempt_notifiers;
907 #endif
908
909 #ifdef CONFIG_BLK_DEV_IO_TRACE
910 unsigned int btrace_seq;
911 #endif
912
913 unsigned int policy;
914 unsigned long max_allowed_capacity;
915 int nr_cpus_allowed;
916 const cpumask_t *cpus_ptr;
917 cpumask_t *user_cpus_ptr;
918 cpumask_t cpus_mask;
919 void *migration_pending;
920 unsigned short migration_disabled;
921 unsigned short migration_flags;
922
923 #ifdef CONFIG_PREEMPT_RCU
924 int rcu_read_lock_nesting;
925 union rcu_special rcu_read_unlock_special;
926 struct list_head rcu_node_entry;
927 struct rcu_node *rcu_blocked_node;
928 #endif /* #ifdef CONFIG_PREEMPT_RCU */
929
930 #ifdef CONFIG_TASKS_RCU
931 unsigned long rcu_tasks_nvcsw;
932 u8 rcu_tasks_holdout;
933 u8 rcu_tasks_idx;
934 int rcu_tasks_idle_cpu;
935 struct list_head rcu_tasks_holdout_list;
936 int rcu_tasks_exit_cpu;
937 struct list_head rcu_tasks_exit_list;
938 #endif /* #ifdef CONFIG_TASKS_RCU */
939
940 #ifdef CONFIG_TASKS_TRACE_RCU
941 int trc_reader_nesting;
942 int trc_ipi_to_cpu;
943 union rcu_special trc_reader_special;
944 struct list_head trc_holdout_list;
945 struct list_head trc_blkd_node;
946 int trc_blkd_cpu;
947 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
948
949 struct sched_info sched_info;
950
951 struct list_head tasks;
952 struct plist_node pushable_tasks;
953 struct rb_node pushable_dl_tasks;
954
955 struct mm_struct *mm;
956 struct mm_struct *active_mm;
957 struct address_space *faults_disabled_mapping;
958
959 int exit_state;
960 int exit_code;
961 int exit_signal;
962 /* The signal sent when the parent dies: */
963 int pdeath_signal;
964 /* JOBCTL_*, siglock protected: */
965 unsigned long jobctl;
966
967 /* Used for emulating ABI behavior of previous Linux versions: */
968 unsigned int personality;
969
970 /* Scheduler bits, serialized by scheduler locks: */
971 unsigned sched_reset_on_fork:1;
972 unsigned sched_contributes_to_load:1;
973 unsigned sched_migrated:1;
974 unsigned sched_task_hot:1;
975
976 /* Force alignment to the next boundary: */
977 unsigned :0;
978
979 /* Unserialized, strictly 'current' */
980
981 /*
982 * This field must not be in the scheduler word above due to wakelist
983 * queueing no longer being serialized by p->on_cpu. However:
984 *
985 * p->XXX = X; ttwu()
986 * schedule() if (p->on_rq && ..) // false
987 * smp_mb__after_spinlock(); if (smp_load_acquire(&p->on_cpu) && //true
988 * deactivate_task() ttwu_queue_wakelist())
989 * p->on_rq = 0; p->sched_remote_wakeup = Y;
990 *
991 * guarantees all stores of 'current' are visible before
992 * ->sched_remote_wakeup gets used, so it can be in this word.
993 */
994 unsigned sched_remote_wakeup:1;
995 #ifdef CONFIG_RT_MUTEXES
996 unsigned sched_rt_mutex:1;
997 #endif
998
999 /* Bit to tell TOMOYO we're in execve(): */
1000 unsigned in_execve:1;
1001 unsigned in_iowait:1;
1002 #ifndef TIF_RESTORE_SIGMASK
1003 unsigned restore_sigmask:1;
1004 #endif
1005 #ifdef CONFIG_MEMCG_V1
1006 unsigned in_user_fault:1;
1007 #endif
1008 #ifdef CONFIG_LRU_GEN
1009 /* whether the LRU algorithm may apply to this access */
1010 unsigned in_lru_fault:1;
1011 #endif
1012 #ifdef CONFIG_COMPAT_BRK
1013 unsigned brk_randomized:1;
1014 #endif
1015 #ifdef CONFIG_CGROUPS
1016 /* disallow userland-initiated cgroup migration */
1017 unsigned no_cgroup_migration:1;
1018 /* task is frozen/stopped (used by the cgroup freezer) */
1019 unsigned frozen:1;
1020 #endif
1021 #ifdef CONFIG_BLK_CGROUP
1022 unsigned use_memdelay:1;
1023 #endif
1024 #ifdef CONFIG_PSI
1025 /* Stalled due to lack of memory */
1026 unsigned in_memstall:1;
1027 #endif
1028 #ifdef CONFIG_PAGE_OWNER
1029 /* Used by page_owner=on to detect recursion in page tracking. */
1030 unsigned in_page_owner:1;
1031 #endif
1032 #ifdef CONFIG_EVENTFD
1033 /* Recursion prevention for eventfd_signal() */
1034 unsigned in_eventfd:1;
1035 #endif
1036 #ifdef CONFIG_ARCH_HAS_CPU_PASID
1037 unsigned pasid_activated:1;
1038 #endif
1039 #ifdef CONFIG_X86_BUS_LOCK_DETECT
1040 unsigned reported_split_lock:1;
1041 #endif
1042 #ifdef CONFIG_TASK_DELAY_ACCT
1043 /* delay due to memory thrashing */
1044 unsigned in_thrashing:1;
1045 #endif
1046 unsigned in_nf_duplicate:1;
1047 #ifdef CONFIG_PREEMPT_RT
1048 struct netdev_xmit net_xmit;
1049 #endif
1050 unsigned long atomic_flags; /* Flags requiring atomic access. */
1051
1052 struct restart_block restart_block;
1053
1054 pid_t pid;
1055 pid_t tgid;
1056
1057 #ifdef CONFIG_STACKPROTECTOR
1058 /* Canary value for the -fstack-protector GCC feature: */
1059 unsigned long stack_canary;
1060 #endif
1061 /*
1062 * Pointers to the (original) parent process, youngest child, younger sibling,
1063 * older sibling, respectively. (p->father can be replaced with
1064 * p->real_parent->pid)
1065 */
1066
1067 /* Real parent process: */
1068 struct task_struct __rcu *real_parent;
1069
1070 /* Recipient of SIGCHLD, wait4() reports: */
1071 struct task_struct __rcu *parent;
1072
1073 /*
1074 * Children/sibling form the list of natural children:
1075 */
1076 struct list_head children;
1077 struct list_head sibling;
1078 struct task_struct *group_leader;
1079
1080 /*
1081 * 'ptraced' is the list of tasks this task is using ptrace() on.
1082 *
1083 * This includes both natural children and PTRACE_ATTACH targets.
1084 * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
1085 */
1086 struct list_head ptraced;
1087 struct list_head ptrace_entry;
1088
1089 /* PID/PID hash table linkage. */
1090 struct pid *thread_pid;
1091 struct hlist_node pid_links[PIDTYPE_MAX];
1092 struct list_head thread_node;
1093
1094 struct completion *vfork_done;
1095
1096 /* CLONE_CHILD_SETTID: */
1097 int __user *set_child_tid;
1098
1099 /* CLONE_CHILD_CLEARTID: */
1100 int __user *clear_child_tid;
1101
1102 /* PF_KTHREAD | PF_IO_WORKER */
1103 void *worker_private;
1104
1105 u64 utime;
1106 u64 stime;
1107 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
1108 u64 utimescaled;
1109 u64 stimescaled;
1110 #endif
1111 u64 gtime;
1112 struct prev_cputime prev_cputime;
1113 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1114 struct vtime vtime;
1115 #endif
1116
1117 #ifdef CONFIG_NO_HZ_FULL
1118 atomic_t tick_dep_mask;
1119 #endif
1120 /* Context switch counts: */
1121 unsigned long nvcsw;
1122 unsigned long nivcsw;
1123
1124 /* Monotonic time in nsecs: */
1125 u64 start_time;
1126
1127 /* Boot based time in nsecs: */
1128 u64 start_boottime;
1129
1130 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
1131 unsigned long min_flt;
1132 unsigned long maj_flt;
1133
1134 /* Empty if CONFIG_POSIX_CPUTIMERS=n */
1135 struct posix_cputimers posix_cputimers;
1136
1137 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK
1138 struct posix_cputimers_work posix_cputimers_work;
1139 #endif
1140
1141 /* Process credentials: */
1142
1143 /* Tracer's credentials at attach: */
1144 const struct cred __rcu *ptracer_cred;
1145
1146 /* Objective and real subjective task credentials (COW): */
1147 const struct cred __rcu *real_cred;
1148
1149 /* Effective (overridable) subjective task credentials (COW): */
1150 const struct cred __rcu *cred;
1151
1152 #ifdef CONFIG_KEYS
1153 /* Cached requested key. */
1154 struct key *cached_requested_key;
1155 #endif
1156
1157 /*
1158 * executable name, excluding path.
1159 *
1160 * - normally initialized begin_new_exec()
1161 * - set it with set_task_comm()
1162 * - strscpy_pad() to ensure it is always NUL-terminated and
1163 * zero-padded
1164 * - task_lock() to ensure the operation is atomic and the name is
1165 * fully updated.
1166 */
1167 char comm[TASK_COMM_LEN];
1168
1169 struct nameidata *nameidata;
1170
1171 #ifdef CONFIG_SYSVIPC
1172 struct sysv_sem sysvsem;
1173 struct sysv_shm sysvshm;
1174 #endif
1175 #ifdef CONFIG_DETECT_HUNG_TASK
1176 unsigned long last_switch_count;
1177 unsigned long last_switch_time;
1178 #endif
1179 /* Filesystem information: */
1180 struct fs_struct *fs;
1181
1182 /* Open file information: */
1183 struct files_struct *files;
1184
1185 #ifdef CONFIG_IO_URING
1186 struct io_uring_task *io_uring;
1187 #endif
1188
1189 /* Namespaces: */
1190 struct nsproxy *nsproxy;
1191
1192 /* Signal handlers: */
1193 struct signal_struct *signal;
1194 struct sighand_struct __rcu *sighand;
1195 sigset_t blocked;
1196 sigset_t real_blocked;
1197 /* Restored if set_restore_sigmask() was used: */
1198 sigset_t saved_sigmask;
1199 struct sigpending pending;
1200 unsigned long sas_ss_sp;
1201 size_t sas_ss_size;
1202 unsigned int sas_ss_flags;
1203
1204 struct callback_head *task_works;
1205
1206 #ifdef CONFIG_AUDIT
1207 #ifdef CONFIG_AUDITSYSCALL
1208 struct audit_context *audit_context;
1209 #endif
1210 kuid_t loginuid;
1211 unsigned int sessionid;
1212 #endif
1213 struct seccomp seccomp;
1214 struct syscall_user_dispatch syscall_dispatch;
1215
1216 /* Thread group tracking: */
1217 u64 parent_exec_id;
1218 u64 self_exec_id;
1219
1220 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
1221 spinlock_t alloc_lock;
1222
1223 /* Protection of the PI data structures: */
1224 raw_spinlock_t pi_lock;
1225
1226 struct wake_q_node wake_q;
1227
1228 #ifdef CONFIG_RT_MUTEXES
1229 /* PI waiters blocked on a rt_mutex held by this task: */
1230 struct rb_root_cached pi_waiters;
1231 /* Updated under owner's pi_lock and rq lock */
1232 struct task_struct *pi_top_task;
1233 /* Deadlock detection and priority inheritance handling: */
1234 struct rt_mutex_waiter *pi_blocked_on;
1235 #endif
1236
1237 struct mutex *blocked_on; /* lock we're blocked on */
1238
1239 #ifdef CONFIG_DETECT_HUNG_TASK_BLOCKER
1240 /*
1241 * Encoded lock address causing task block (lower 2 bits = type from
1242 * <linux/hung_task.h>). Accessed via hung_task_*() helpers.
1243 */
1244 unsigned long blocker;
1245 #endif
1246
1247 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1248 int non_block_count;
1249 #endif
1250
1251 #ifdef CONFIG_TRACE_IRQFLAGS
1252 struct irqtrace_events irqtrace;
1253 unsigned int hardirq_threaded;
1254 u64 hardirq_chain_key;
1255 int softirqs_enabled;
1256 int softirq_context;
1257 int irq_config;
1258 #endif
1259 #ifdef CONFIG_PREEMPT_RT
1260 int softirq_disable_cnt;
1261 #endif
1262
1263 #ifdef CONFIG_LOCKDEP
1264 # define MAX_LOCK_DEPTH 48UL
1265 u64 curr_chain_key;
1266 int lockdep_depth;
1267 unsigned int lockdep_recursion;
1268 struct held_lock held_locks[MAX_LOCK_DEPTH];
1269 #endif
1270
1271 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP)
1272 unsigned int in_ubsan;
1273 #endif
1274
1275 /* Journalling filesystem info: */
1276 void *journal_info;
1277
1278 /* Stacked block device info: */
1279 struct bio_list *bio_list;
1280
1281 /* Stack plugging: */
1282 struct blk_plug *plug;
1283
1284 /* VM state: */
1285 struct reclaim_state *reclaim_state;
1286
1287 struct io_context *io_context;
1288
1289 #ifdef CONFIG_COMPACTION
1290 struct capture_control *capture_control;
1291 #endif
1292 /* Ptrace state: */
1293 unsigned long ptrace_message;
1294 kernel_siginfo_t *last_siginfo;
1295
1296 struct task_io_accounting ioac;
1297 #ifdef CONFIG_PSI
1298 /* Pressure stall state */
1299 unsigned int psi_flags;
1300 #endif
1301 #ifdef CONFIG_TASK_XACCT
1302 /* Accumulated RSS usage: */
1303 u64 acct_rss_mem1;
1304 /* Accumulated virtual memory usage: */
1305 u64 acct_vm_mem1;
1306 /* stime + utime since last update: */
1307 u64 acct_timexpd;
1308 #endif
1309 #ifdef CONFIG_CPUSETS
1310 /* Protected by ->alloc_lock: */
1311 nodemask_t mems_allowed;
1312 /* Sequence number to catch updates: */
1313 seqcount_spinlock_t mems_allowed_seq;
1314 int cpuset_mem_spread_rotor;
1315 #endif
1316 #ifdef CONFIG_CGROUPS
1317 /* Control Group info protected by css_set_lock: */
1318 struct css_set __rcu *cgroups;
1319 /* cg_list protected by css_set_lock and tsk->alloc_lock: */
1320 struct list_head cg_list;
1321 #endif
1322 #ifdef CONFIG_X86_CPU_RESCTRL
1323 u32 closid;
1324 u32 rmid;
1325 #endif
1326 #ifdef CONFIG_FUTEX
1327 struct robust_list_head __user *robust_list;
1328 #ifdef CONFIG_COMPAT
1329 struct compat_robust_list_head __user *compat_robust_list;
1330 #endif
1331 struct list_head pi_state_list;
1332 struct futex_pi_state *pi_state_cache;
1333 struct mutex futex_exit_mutex;
1334 unsigned int futex_state;
1335 #endif
1336 #ifdef CONFIG_PERF_EVENTS
1337 u8 perf_recursion[PERF_NR_CONTEXTS];
1338 struct perf_event_context *perf_event_ctxp;
1339 struct mutex perf_event_mutex;
1340 struct list_head perf_event_list;
1341 struct perf_ctx_data __rcu *perf_ctx_data;
1342 #endif
1343 #ifdef CONFIG_DEBUG_PREEMPT
1344 unsigned long preempt_disable_ip;
1345 #endif
1346 #ifdef CONFIG_NUMA
1347 /* Protected by alloc_lock: */
1348 struct mempolicy *mempolicy;
1349 short il_prev;
1350 u8 il_weight;
1351 short pref_node_fork;
1352 #endif
1353 #ifdef CONFIG_NUMA_BALANCING
1354 int numa_scan_seq;
1355 unsigned int numa_scan_period;
1356 unsigned int numa_scan_period_max;
1357 int numa_preferred_nid;
1358 unsigned long numa_migrate_retry;
1359 /* Migration stamp: */
1360 u64 node_stamp;
1361 u64 last_task_numa_placement;
1362 u64 last_sum_exec_runtime;
1363 struct callback_head numa_work;
1364
1365 /*
1366 * This pointer is only modified for current in syscall and
1367 * pagefault context (and for tasks being destroyed), so it can be read
1368 * from any of the following contexts:
1369 * - RCU read-side critical section
1370 * - current->numa_group from everywhere
1371 * - task's runqueue locked, task not running
1372 */
1373 struct numa_group __rcu *numa_group;
1374
1375 /*
1376 * numa_faults is an array split into four regions:
1377 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1378 * in this precise order.
1379 *
1380 * faults_memory: Exponential decaying average of faults on a per-node
1381 * basis. Scheduling placement decisions are made based on these
1382 * counts. The values remain static for the duration of a PTE scan.
1383 * faults_cpu: Track the nodes the process was running on when a NUMA
1384 * hinting fault was incurred.
1385 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1386 * during the current scan window. When the scan completes, the counts
1387 * in faults_memory and faults_cpu decay and these values are copied.
1388 */
1389 unsigned long *numa_faults;
1390 unsigned long total_numa_faults;
1391
1392 /*
1393 * numa_faults_locality tracks if faults recorded during the last
1394 * scan window were remote/local or failed to migrate. The task scan
1395 * period is adapted based on the locality of the faults with different
1396 * weights depending on whether they were shared or private faults
1397 */
1398 unsigned long numa_faults_locality[3];
1399
1400 unsigned long numa_pages_migrated;
1401 #endif /* CONFIG_NUMA_BALANCING */
1402
1403 #ifdef CONFIG_RSEQ
1404 struct rseq __user *rseq;
1405 u32 rseq_len;
1406 u32 rseq_sig;
1407 /*
1408 * RmW on rseq_event_mask must be performed atomically
1409 * with respect to preemption.
1410 */
1411 unsigned long rseq_event_mask;
1412 # ifdef CONFIG_DEBUG_RSEQ
1413 /*
1414 * This is a place holder to save a copy of the rseq fields for
1415 * validation of read-only fields. The struct rseq has a
1416 * variable-length array at the end, so it cannot be used
1417 * directly. Reserve a size large enough for the known fields.
1418 */
1419 char rseq_fields[sizeof(struct rseq)];
1420 # endif
1421 #endif
1422
1423 #ifdef CONFIG_SCHED_MM_CID
1424 int mm_cid; /* Current cid in mm */
1425 int last_mm_cid; /* Most recent cid in mm */
1426 int migrate_from_cpu;
1427 int mm_cid_active; /* Whether cid bitmap is active */
1428 struct callback_head cid_work;
1429 #endif
1430
1431 struct tlbflush_unmap_batch tlb_ubc;
1432
1433 /* Cache last used pipe for splice(): */
1434 struct pipe_inode_info *splice_pipe;
1435
1436 struct page_frag task_frag;
1437
1438 #ifdef CONFIG_TASK_DELAY_ACCT
1439 struct task_delay_info *delays;
1440 #endif
1441
1442 #ifdef CONFIG_FAULT_INJECTION
1443 int make_it_fail;
1444 unsigned int fail_nth;
1445 #endif
1446 /*
1447 * When (nr_dirtied >= nr_dirtied_pause), it's time to call
1448 * balance_dirty_pages() for a dirty throttling pause:
1449 */
1450 int nr_dirtied;
1451 int nr_dirtied_pause;
1452 /* Start of a write-and-pause period: */
1453 unsigned long dirty_paused_when;
1454
1455 #ifdef CONFIG_LATENCYTOP
1456 int latency_record_count;
1457 struct latency_record latency_record[LT_SAVECOUNT];
1458 #endif
1459 /*
1460 * Time slack values; these are used to round up poll() and
1461 * select() etc timeout values. These are in nanoseconds.
1462 */
1463 u64 timer_slack_ns;
1464 u64 default_timer_slack_ns;
1465
1466 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
1467 unsigned int kasan_depth;
1468 #endif
1469
1470 #ifdef CONFIG_KCSAN
1471 struct kcsan_ctx kcsan_ctx;
1472 #ifdef CONFIG_TRACE_IRQFLAGS
1473 struct irqtrace_events kcsan_save_irqtrace;
1474 #endif
1475 #ifdef CONFIG_KCSAN_WEAK_MEMORY
1476 int kcsan_stack_depth;
1477 #endif
1478 #endif
1479
1480 #ifdef CONFIG_KMSAN
1481 struct kmsan_ctx kmsan_ctx;
1482 #endif
1483
1484 #if IS_ENABLED(CONFIG_KUNIT)
1485 struct kunit *kunit_test;
1486 #endif
1487
1488 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1489 /* Index of current stored address in ret_stack: */
1490 int curr_ret_stack;
1491 int curr_ret_depth;
1492
1493 /* Stack of return addresses for return function tracing: */
1494 unsigned long *ret_stack;
1495
1496 /* Timestamp for last schedule: */
1497 unsigned long long ftrace_timestamp;
1498 unsigned long long ftrace_sleeptime;
1499
1500 /*
1501 * Number of functions that haven't been traced
1502 * because of depth overrun:
1503 */
1504 atomic_t trace_overrun;
1505
1506 /* Pause tracing: */
1507 atomic_t tracing_graph_pause;
1508 #endif
1509
1510 #ifdef CONFIG_TRACING
1511 /* Bitmask and counter of trace recursion: */
1512 unsigned long trace_recursion;
1513 #endif /* CONFIG_TRACING */
1514
1515 #ifdef CONFIG_KCOV
1516 /* See kernel/kcov.c for more details. */
1517
1518 /* Coverage collection mode enabled for this task (0 if disabled): */
1519 unsigned int kcov_mode;
1520
1521 /* Size of the kcov_area: */
1522 unsigned int kcov_size;
1523
1524 /* Buffer for coverage collection: */
1525 void *kcov_area;
1526
1527 /* KCOV descriptor wired with this task or NULL: */
1528 struct kcov *kcov;
1529
1530 /* KCOV common handle for remote coverage collection: */
1531 u64 kcov_handle;
1532
1533 /* KCOV sequence number: */
1534 int kcov_sequence;
1535
1536 /* Collect coverage from softirq context: */
1537 unsigned int kcov_softirq;
1538 #endif
1539
1540 #ifdef CONFIG_MEMCG_V1
1541 struct mem_cgroup *memcg_in_oom;
1542 #endif
1543
1544 #ifdef CONFIG_MEMCG
1545 /* Number of pages to reclaim on returning to userland: */
1546 unsigned int memcg_nr_pages_over_high;
1547
1548 /* Used by memcontrol for targeted memcg charge: */
1549 struct mem_cgroup *active_memcg;
1550
1551 /* Cache for current->cgroups->memcg->objcg lookups: */
1552 struct obj_cgroup *objcg;
1553 #endif
1554
1555 #ifdef CONFIG_BLK_CGROUP
1556 struct gendisk *throttle_disk;
1557 #endif
1558
1559 #ifdef CONFIG_UPROBES
1560 struct uprobe_task *utask;
1561 #endif
1562 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1563 unsigned int sequential_io;
1564 unsigned int sequential_io_avg;
1565 #endif
1566 struct kmap_ctrl kmap_ctrl;
1567 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1568 unsigned long task_state_change;
1569 # ifdef CONFIG_PREEMPT_RT
1570 unsigned long saved_state_change;
1571 # endif
1572 #endif
1573 struct rcu_head rcu;
1574 refcount_t rcu_users;
1575 int pagefault_disabled;
1576 #ifdef CONFIG_MMU
1577 struct task_struct *oom_reaper_list;
1578 struct timer_list oom_reaper_timer;
1579 #endif
1580 #ifdef CONFIG_VMAP_STACK
1581 struct vm_struct *stack_vm_area;
1582 #endif
1583 #ifdef CONFIG_THREAD_INFO_IN_TASK
1584 /* A live task holds one reference: */
1585 refcount_t stack_refcount;
1586 #endif
1587 #ifdef CONFIG_LIVEPATCH
1588 int patch_state;
1589 #endif
1590 #ifdef CONFIG_SECURITY
1591 /* Used by LSM modules for access restriction: */
1592 void *security;
1593 #endif
1594 #ifdef CONFIG_BPF_SYSCALL
1595 /* Used by BPF task local storage */
1596 struct bpf_local_storage __rcu *bpf_storage;
1597 /* Used for BPF run context */
1598 struct bpf_run_ctx *bpf_ctx;
1599 #endif
1600 /* Used by BPF for per-TASK xdp storage */
1601 struct bpf_net_context *bpf_net_context;
1602
1603 #ifdef CONFIG_KSTACK_ERASE
1604 unsigned long lowest_stack;
1605 #endif
1606 #ifdef CONFIG_KSTACK_ERASE_METRICS
1607 unsigned long prev_lowest_stack;
1608 #endif
1609
1610 #ifdef CONFIG_X86_MCE
1611 void __user *mce_vaddr;
1612 __u64 mce_kflags;
1613 u64 mce_addr;
1614 __u64 mce_ripv : 1,
1615 mce_whole_page : 1,
1616 __mce_reserved : 62;
1617 struct callback_head mce_kill_me;
1618 int mce_count;
1619 #endif
1620
1621 #ifdef CONFIG_KRETPROBES
1622 struct llist_head kretprobe_instances;
1623 #endif
1624 #ifdef CONFIG_RETHOOK
1625 struct llist_head rethooks;
1626 #endif
1627
1628 #ifdef CONFIG_ARCH_HAS_PARANOID_L1D_FLUSH
1629 /*
1630 * If L1D flush is supported on mm context switch
1631 * then we use this callback head to queue kill work
1632 * to kill tasks that are not running on SMT disabled
1633 * cores
1634 */
1635 struct callback_head l1d_flush_kill;
1636 #endif
1637
1638 #ifdef CONFIG_RV
1639 /*
1640 * Per-task RV monitor, fixed in CONFIG_RV_PER_TASK_MONITORS.
1641 * If memory becomes a concern, we can think about a dynamic method.
1642 */
1643 union rv_task_monitor rv[CONFIG_RV_PER_TASK_MONITORS];
1644 #endif
1645
1646 #ifdef CONFIG_USER_EVENTS
1647 struct user_event_mm *user_event_mm;
1648 #endif
1649
1650 #ifdef CONFIG_UNWIND_USER
1651 struct unwind_task_info unwind_info;
1652 #endif
1653
1654 /* CPU-specific state of this task: */
1655 struct thread_struct thread;
1656
1657 /*
1658 * New fields for task_struct should be added above here, so that
1659 * they are included in the randomized portion of task_struct.
1660 */
1661 randomized_struct_fields_end
1662 } __attribute__ ((aligned (64)));
1663
1664 #ifdef CONFIG_SCHED_PROXY_EXEC
1665 DECLARE_STATIC_KEY_TRUE(__sched_proxy_exec);
sched_proxy_exec(void)1666 static inline bool sched_proxy_exec(void)
1667 {
1668 return static_branch_likely(&__sched_proxy_exec);
1669 }
1670 #else
sched_proxy_exec(void)1671 static inline bool sched_proxy_exec(void)
1672 {
1673 return false;
1674 }
1675 #endif
1676
1677 #define TASK_REPORT_IDLE (TASK_REPORT + 1)
1678 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1)
1679
__task_state_index(unsigned int tsk_state,unsigned int tsk_exit_state)1680 static inline unsigned int __task_state_index(unsigned int tsk_state,
1681 unsigned int tsk_exit_state)
1682 {
1683 unsigned int state = (tsk_state | tsk_exit_state) & TASK_REPORT;
1684
1685 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX);
1686
1687 if ((tsk_state & TASK_IDLE) == TASK_IDLE)
1688 state = TASK_REPORT_IDLE;
1689
1690 /*
1691 * We're lying here, but rather than expose a completely new task state
1692 * to userspace, we can make this appear as if the task has gone through
1693 * a regular rt_mutex_lock() call.
1694 * Report frozen tasks as uninterruptible.
1695 */
1696 if ((tsk_state & TASK_RTLOCK_WAIT) || (tsk_state & TASK_FROZEN))
1697 state = TASK_UNINTERRUPTIBLE;
1698
1699 return fls(state);
1700 }
1701
task_state_index(struct task_struct * tsk)1702 static inline unsigned int task_state_index(struct task_struct *tsk)
1703 {
1704 return __task_state_index(READ_ONCE(tsk->__state), tsk->exit_state);
1705 }
1706
task_index_to_char(unsigned int state)1707 static inline char task_index_to_char(unsigned int state)
1708 {
1709 static const char state_char[] = "RSDTtXZPI";
1710
1711 BUILD_BUG_ON(TASK_REPORT_MAX * 2 != 1 << (sizeof(state_char) - 1));
1712
1713 return state_char[state];
1714 }
1715
task_state_to_char(struct task_struct * tsk)1716 static inline char task_state_to_char(struct task_struct *tsk)
1717 {
1718 return task_index_to_char(task_state_index(tsk));
1719 }
1720
1721 extern struct pid *cad_pid;
1722
1723 /*
1724 * Per process flags
1725 */
1726 #define PF_VCPU 0x00000001 /* I'm a virtual CPU */
1727 #define PF_IDLE 0x00000002 /* I am an IDLE thread */
1728 #define PF_EXITING 0x00000004 /* Getting shut down */
1729 #define PF_POSTCOREDUMP 0x00000008 /* Coredumps should ignore this task */
1730 #define PF_IO_WORKER 0x00000010 /* Task is an IO worker */
1731 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */
1732 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */
1733 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */
1734 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */
1735 #define PF_DUMPCORE 0x00000200 /* Dumped core */
1736 #define PF_SIGNALED 0x00000400 /* Killed by a signal */
1737 #define PF_MEMALLOC 0x00000800 /* Allocating memory to free memory. See memalloc_noreclaim_save() */
1738 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */
1739 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */
1740 #define PF_USER_WORKER 0x00004000 /* Kernel thread cloned from userspace thread */
1741 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */
1742 #define PF_KCOMPACTD 0x00010000 /* I am kcompactd */
1743 #define PF_KSWAPD 0x00020000 /* I am kswapd */
1744 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocations inherit GFP_NOFS. See memalloc_nfs_save() */
1745 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocations inherit GFP_NOIO. See memalloc_noio_save() */
1746 #define PF_LOCAL_THROTTLE 0x00100000 /* Throttle writes only against the bdi I write to,
1747 * I am cleaning dirty pages from some other bdi. */
1748 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */
1749 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */
1750 #define PF__HOLE__00800000 0x00800000
1751 #define PF__HOLE__01000000 0x01000000
1752 #define PF__HOLE__02000000 0x02000000
1753 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */
1754 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */
1755 #define PF_MEMALLOC_PIN 0x10000000 /* Allocations constrained to zones which allow long term pinning.
1756 * See memalloc_pin_save() */
1757 #define PF_BLOCK_TS 0x20000000 /* plug has ts that needs updating */
1758 #define PF__HOLE__40000000 0x40000000
1759 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */
1760
1761 /*
1762 * Only the _current_ task can read/write to tsk->flags, but other
1763 * tasks can access tsk->flags in readonly mode for example
1764 * with tsk_used_math (like during threaded core dumping).
1765 * There is however an exception to this rule during ptrace
1766 * or during fork: the ptracer task is allowed to write to the
1767 * child->flags of its traced child (same goes for fork, the parent
1768 * can write to the child->flags), because we're guaranteed the
1769 * child is not running and in turn not changing child->flags
1770 * at the same time the parent does it.
1771 */
1772 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1773 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1774 #define clear_used_math() clear_stopped_child_used_math(current)
1775 #define set_used_math() set_stopped_child_used_math(current)
1776
1777 #define conditional_stopped_child_used_math(condition, child) \
1778 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1779
1780 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current)
1781
1782 #define copy_to_stopped_child_used_math(child) \
1783 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1784
1785 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1786 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1787 #define used_math() tsk_used_math(current)
1788
is_percpu_thread(void)1789 static __always_inline bool is_percpu_thread(void)
1790 {
1791 return (current->flags & PF_NO_SETAFFINITY) &&
1792 (current->nr_cpus_allowed == 1);
1793 }
1794
1795 /* Per-process atomic flags. */
1796 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */
1797 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */
1798 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */
1799 #define PFA_SPEC_SSB_DISABLE 3 /* Speculative Store Bypass disabled */
1800 #define PFA_SPEC_SSB_FORCE_DISABLE 4 /* Speculative Store Bypass force disabled*/
1801 #define PFA_SPEC_IB_DISABLE 5 /* Indirect branch speculation restricted */
1802 #define PFA_SPEC_IB_FORCE_DISABLE 6 /* Indirect branch speculation permanently restricted */
1803 #define PFA_SPEC_SSB_NOEXEC 7 /* Speculative Store Bypass clear on execve() */
1804
1805 #define TASK_PFA_TEST(name, func) \
1806 static inline bool task_##func(struct task_struct *p) \
1807 { return test_bit(PFA_##name, &p->atomic_flags); }
1808
1809 #define TASK_PFA_SET(name, func) \
1810 static inline void task_set_##func(struct task_struct *p) \
1811 { set_bit(PFA_##name, &p->atomic_flags); }
1812
1813 #define TASK_PFA_CLEAR(name, func) \
1814 static inline void task_clear_##func(struct task_struct *p) \
1815 { clear_bit(PFA_##name, &p->atomic_flags); }
1816
TASK_PFA_TEST(NO_NEW_PRIVS,no_new_privs)1817 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
1818 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
1819
1820 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
1821 TASK_PFA_SET(SPREAD_PAGE, spread_page)
1822 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
1823
1824 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
1825 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
1826 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
1827
1828 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable)
1829 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable)
1830 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable)
1831
1832 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1833 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1834 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1835
1836 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1837 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1838
1839 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable)
1840 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable)
1841 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable)
1842
1843 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1844 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1845
1846 static inline void
1847 current_restore_flags(unsigned long orig_flags, unsigned long flags)
1848 {
1849 current->flags &= ~flags;
1850 current->flags |= orig_flags & flags;
1851 }
1852
1853 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
1854 extern int task_can_attach(struct task_struct *p);
1855 extern int dl_bw_alloc(int cpu, u64 dl_bw);
1856 extern void dl_bw_free(int cpu, u64 dl_bw);
1857
1858 /* do_set_cpus_allowed() - consider using set_cpus_allowed_ptr() instead */
1859 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
1860
1861 /**
1862 * set_cpus_allowed_ptr - set CPU affinity mask of a task
1863 * @p: the task
1864 * @new_mask: CPU affinity mask
1865 *
1866 * Return: zero if successful, or a negative error code
1867 */
1868 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
1869 extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node);
1870 extern void release_user_cpus_ptr(struct task_struct *p);
1871 extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask);
1872 extern void force_compatible_cpus_allowed_ptr(struct task_struct *p);
1873 extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p);
1874
1875 extern int yield_to(struct task_struct *p, bool preempt);
1876 extern void set_user_nice(struct task_struct *p, long nice);
1877 extern int task_prio(const struct task_struct *p);
1878
1879 /**
1880 * task_nice - return the nice value of a given task.
1881 * @p: the task in question.
1882 *
1883 * Return: The nice value [ -20 ... 0 ... 19 ].
1884 */
task_nice(const struct task_struct * p)1885 static inline int task_nice(const struct task_struct *p)
1886 {
1887 return PRIO_TO_NICE((p)->static_prio);
1888 }
1889
1890 extern int can_nice(const struct task_struct *p, const int nice);
1891 extern int task_curr(const struct task_struct *p);
1892 extern int idle_cpu(int cpu);
1893 extern int available_idle_cpu(int cpu);
1894 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *);
1895 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *);
1896 extern void sched_set_fifo(struct task_struct *p);
1897 extern void sched_set_fifo_low(struct task_struct *p);
1898 extern void sched_set_normal(struct task_struct *p, int nice);
1899 extern int sched_setattr(struct task_struct *, const struct sched_attr *);
1900 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *);
1901 extern struct task_struct *idle_task(int cpu);
1902
1903 /**
1904 * is_idle_task - is the specified task an idle task?
1905 * @p: the task in question.
1906 *
1907 * Return: 1 if @p is an idle task. 0 otherwise.
1908 */
is_idle_task(const struct task_struct * p)1909 static __always_inline bool is_idle_task(const struct task_struct *p)
1910 {
1911 return !!(p->flags & PF_IDLE);
1912 }
1913
1914 extern struct task_struct *curr_task(int cpu);
1915 extern void ia64_set_curr_task(int cpu, struct task_struct *p);
1916
1917 void yield(void);
1918
1919 union thread_union {
1920 struct task_struct task;
1921 #ifndef CONFIG_THREAD_INFO_IN_TASK
1922 struct thread_info thread_info;
1923 #endif
1924 unsigned long stack[THREAD_SIZE/sizeof(long)];
1925 };
1926
1927 #ifndef CONFIG_THREAD_INFO_IN_TASK
1928 extern struct thread_info init_thread_info;
1929 #endif
1930
1931 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
1932
1933 #ifdef CONFIG_THREAD_INFO_IN_TASK
1934 # define task_thread_info(task) (&(task)->thread_info)
1935 #else
1936 # define task_thread_info(task) ((struct thread_info *)(task)->stack)
1937 #endif
1938
1939 /*
1940 * find a task by one of its numerical ids
1941 *
1942 * find_task_by_pid_ns():
1943 * finds a task by its pid in the specified namespace
1944 * find_task_by_vpid():
1945 * finds a task by its virtual pid
1946 *
1947 * see also find_vpid() etc in include/linux/pid.h
1948 */
1949
1950 extern struct task_struct *find_task_by_vpid(pid_t nr);
1951 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns);
1952
1953 /*
1954 * find a task by its virtual pid and get the task struct
1955 */
1956 extern struct task_struct *find_get_task_by_vpid(pid_t nr);
1957
1958 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
1959 extern int wake_up_process(struct task_struct *tsk);
1960 extern void wake_up_new_task(struct task_struct *tsk);
1961
1962 extern void kick_process(struct task_struct *tsk);
1963
1964 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
1965 #define set_task_comm(tsk, from) ({ \
1966 BUILD_BUG_ON(sizeof(from) != TASK_COMM_LEN); \
1967 __set_task_comm(tsk, from, false); \
1968 })
1969
1970 /*
1971 * - Why not use task_lock()?
1972 * User space can randomly change their names anyway, so locking for readers
1973 * doesn't make sense. For writers, locking is probably necessary, as a race
1974 * condition could lead to long-term mixed results.
1975 * The strscpy_pad() in __set_task_comm() can ensure that the task comm is
1976 * always NUL-terminated and zero-padded. Therefore the race condition between
1977 * reader and writer is not an issue.
1978 *
1979 * - BUILD_BUG_ON() can help prevent the buf from being truncated.
1980 * Since the callers don't perform any return value checks, this safeguard is
1981 * necessary.
1982 */
1983 #define get_task_comm(buf, tsk) ({ \
1984 BUILD_BUG_ON(sizeof(buf) < TASK_COMM_LEN); \
1985 strscpy_pad(buf, (tsk)->comm); \
1986 buf; \
1987 })
1988
scheduler_ipi(void)1989 static __always_inline void scheduler_ipi(void)
1990 {
1991 /*
1992 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting
1993 * TIF_NEED_RESCHED remotely (for the first time) will also send
1994 * this IPI.
1995 */
1996 preempt_fold_need_resched();
1997 }
1998
1999 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state);
2000
2001 /*
2002 * Set thread flags in other task's structures.
2003 * See asm/thread_info.h for TIF_xxxx flags available:
2004 */
set_tsk_thread_flag(struct task_struct * tsk,int flag)2005 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2006 {
2007 set_ti_thread_flag(task_thread_info(tsk), flag);
2008 }
2009
clear_tsk_thread_flag(struct task_struct * tsk,int flag)2010 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2011 {
2012 clear_ti_thread_flag(task_thread_info(tsk), flag);
2013 }
2014
update_tsk_thread_flag(struct task_struct * tsk,int flag,bool value)2015 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag,
2016 bool value)
2017 {
2018 update_ti_thread_flag(task_thread_info(tsk), flag, value);
2019 }
2020
test_and_set_tsk_thread_flag(struct task_struct * tsk,int flag)2021 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2022 {
2023 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2024 }
2025
test_and_clear_tsk_thread_flag(struct task_struct * tsk,int flag)2026 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2027 {
2028 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2029 }
2030
test_tsk_thread_flag(struct task_struct * tsk,int flag)2031 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2032 {
2033 return test_ti_thread_flag(task_thread_info(tsk), flag);
2034 }
2035
set_tsk_need_resched(struct task_struct * tsk)2036 static inline void set_tsk_need_resched(struct task_struct *tsk)
2037 {
2038 if (tracepoint_enabled(sched_set_need_resched_tp) &&
2039 !test_tsk_thread_flag(tsk, TIF_NEED_RESCHED))
2040 __trace_set_need_resched(tsk, TIF_NEED_RESCHED);
2041 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2042 }
2043
clear_tsk_need_resched(struct task_struct * tsk)2044 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2045 {
2046 atomic_long_andnot(_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY,
2047 (atomic_long_t *)&task_thread_info(tsk)->flags);
2048 }
2049
test_tsk_need_resched(struct task_struct * tsk)2050 static inline int test_tsk_need_resched(struct task_struct *tsk)
2051 {
2052 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2053 }
2054
2055 /*
2056 * cond_resched() and cond_resched_lock(): latency reduction via
2057 * explicit rescheduling in places that are safe. The return
2058 * value indicates whether a reschedule was done in fact.
2059 * cond_resched_lock() will drop the spinlock before scheduling,
2060 */
2061 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC)
2062 extern int __cond_resched(void);
2063
2064 #if defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL)
2065
2066 DECLARE_STATIC_CALL(cond_resched, __cond_resched);
2067
_cond_resched(void)2068 static __always_inline int _cond_resched(void)
2069 {
2070 return static_call_mod(cond_resched)();
2071 }
2072
2073 #elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY)
2074
2075 extern int dynamic_cond_resched(void);
2076
_cond_resched(void)2077 static __always_inline int _cond_resched(void)
2078 {
2079 return dynamic_cond_resched();
2080 }
2081
2082 #else /* !CONFIG_PREEMPTION */
2083
_cond_resched(void)2084 static inline int _cond_resched(void)
2085 {
2086 return __cond_resched();
2087 }
2088
2089 #endif /* PREEMPT_DYNAMIC && CONFIG_HAVE_PREEMPT_DYNAMIC_CALL */
2090
2091 #else /* CONFIG_PREEMPTION && !CONFIG_PREEMPT_DYNAMIC */
2092
_cond_resched(void)2093 static inline int _cond_resched(void)
2094 {
2095 return 0;
2096 }
2097
2098 #endif /* !CONFIG_PREEMPTION || CONFIG_PREEMPT_DYNAMIC */
2099
2100 #define cond_resched() ({ \
2101 __might_resched(__FILE__, __LINE__, 0); \
2102 _cond_resched(); \
2103 })
2104
2105 extern int __cond_resched_lock(spinlock_t *lock);
2106 extern int __cond_resched_rwlock_read(rwlock_t *lock);
2107 extern int __cond_resched_rwlock_write(rwlock_t *lock);
2108
2109 #define MIGHT_RESCHED_RCU_SHIFT 8
2110 #define MIGHT_RESCHED_PREEMPT_MASK ((1U << MIGHT_RESCHED_RCU_SHIFT) - 1)
2111
2112 #ifndef CONFIG_PREEMPT_RT
2113 /*
2114 * Non RT kernels have an elevated preempt count due to the held lock,
2115 * but are not allowed to be inside a RCU read side critical section
2116 */
2117 # define PREEMPT_LOCK_RESCHED_OFFSETS PREEMPT_LOCK_OFFSET
2118 #else
2119 /*
2120 * spin/rw_lock() on RT implies rcu_read_lock(). The might_sleep() check in
2121 * cond_resched*lock() has to take that into account because it checks for
2122 * preempt_count() and rcu_preempt_depth().
2123 */
2124 # define PREEMPT_LOCK_RESCHED_OFFSETS \
2125 (PREEMPT_LOCK_OFFSET + (1U << MIGHT_RESCHED_RCU_SHIFT))
2126 #endif
2127
2128 #define cond_resched_lock(lock) ({ \
2129 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \
2130 __cond_resched_lock(lock); \
2131 })
2132
2133 #define cond_resched_rwlock_read(lock) ({ \
2134 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \
2135 __cond_resched_rwlock_read(lock); \
2136 })
2137
2138 #define cond_resched_rwlock_write(lock) ({ \
2139 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \
2140 __cond_resched_rwlock_write(lock); \
2141 })
2142
2143 #ifndef CONFIG_PREEMPT_RT
__get_task_blocked_on(struct task_struct * p)2144 static inline struct mutex *__get_task_blocked_on(struct task_struct *p)
2145 {
2146 struct mutex *m = p->blocked_on;
2147
2148 if (m)
2149 lockdep_assert_held_once(&m->wait_lock);
2150 return m;
2151 }
2152
__set_task_blocked_on(struct task_struct * p,struct mutex * m)2153 static inline void __set_task_blocked_on(struct task_struct *p, struct mutex *m)
2154 {
2155 WARN_ON_ONCE(!m);
2156 /* The task should only be setting itself as blocked */
2157 WARN_ON_ONCE(p != current);
2158 /* Currently we serialize blocked_on under the mutex::wait_lock */
2159 lockdep_assert_held_once(&m->wait_lock);
2160 /*
2161 * Check ensure we don't overwrite existing mutex value
2162 * with a different mutex. Note, setting it to the same
2163 * lock repeatedly is ok.
2164 */
2165 WARN_ON_ONCE(p->blocked_on && p->blocked_on != m);
2166 p->blocked_on = m;
2167 }
2168
set_task_blocked_on(struct task_struct * p,struct mutex * m)2169 static inline void set_task_blocked_on(struct task_struct *p, struct mutex *m)
2170 {
2171 guard(raw_spinlock_irqsave)(&m->wait_lock);
2172 __set_task_blocked_on(p, m);
2173 }
2174
__clear_task_blocked_on(struct task_struct * p,struct mutex * m)2175 static inline void __clear_task_blocked_on(struct task_struct *p, struct mutex *m)
2176 {
2177 WARN_ON_ONCE(!m);
2178 /* Currently we serialize blocked_on under the mutex::wait_lock */
2179 lockdep_assert_held_once(&m->wait_lock);
2180 /*
2181 * There may be cases where we re-clear already cleared
2182 * blocked_on relationships, but make sure we are not
2183 * clearing the relationship with a different lock.
2184 */
2185 WARN_ON_ONCE(m && p->blocked_on && p->blocked_on != m);
2186 p->blocked_on = NULL;
2187 }
2188
clear_task_blocked_on(struct task_struct * p,struct mutex * m)2189 static inline void clear_task_blocked_on(struct task_struct *p, struct mutex *m)
2190 {
2191 guard(raw_spinlock_irqsave)(&m->wait_lock);
2192 __clear_task_blocked_on(p, m);
2193 }
2194 #else
__clear_task_blocked_on(struct task_struct * p,struct rt_mutex * m)2195 static inline void __clear_task_blocked_on(struct task_struct *p, struct rt_mutex *m)
2196 {
2197 }
2198
clear_task_blocked_on(struct task_struct * p,struct rt_mutex * m)2199 static inline void clear_task_blocked_on(struct task_struct *p, struct rt_mutex *m)
2200 {
2201 }
2202 #endif /* !CONFIG_PREEMPT_RT */
2203
need_resched(void)2204 static __always_inline bool need_resched(void)
2205 {
2206 return unlikely(tif_need_resched());
2207 }
2208
2209 /*
2210 * Wrappers for p->thread_info->cpu access. No-op on UP.
2211 */
2212 #ifdef CONFIG_SMP
2213
task_cpu(const struct task_struct * p)2214 static inline unsigned int task_cpu(const struct task_struct *p)
2215 {
2216 return READ_ONCE(task_thread_info(p)->cpu);
2217 }
2218
2219 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2220
2221 #else
2222
task_cpu(const struct task_struct * p)2223 static inline unsigned int task_cpu(const struct task_struct *p)
2224 {
2225 return 0;
2226 }
2227
set_task_cpu(struct task_struct * p,unsigned int cpu)2228 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2229 {
2230 }
2231
2232 #endif /* CONFIG_SMP */
2233
task_is_runnable(struct task_struct * p)2234 static inline bool task_is_runnable(struct task_struct *p)
2235 {
2236 return p->on_rq && !p->se.sched_delayed;
2237 }
2238
2239 extern bool sched_task_on_rq(struct task_struct *p);
2240 extern unsigned long get_wchan(struct task_struct *p);
2241 extern struct task_struct *cpu_curr_snapshot(int cpu);
2242
2243 /*
2244 * In order to reduce various lock holder preemption latencies provide an
2245 * interface to see if a vCPU is currently running or not.
2246 *
2247 * This allows us to terminate optimistic spin loops and block, analogous to
2248 * the native optimistic spin heuristic of testing if the lock owner task is
2249 * running or not.
2250 */
2251 #ifndef vcpu_is_preempted
vcpu_is_preempted(int cpu)2252 static inline bool vcpu_is_preempted(int cpu)
2253 {
2254 return false;
2255 }
2256 #endif
2257
2258 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2259 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2260
2261 #ifndef TASK_SIZE_OF
2262 #define TASK_SIZE_OF(tsk) TASK_SIZE
2263 #endif
2264
owner_on_cpu(struct task_struct * owner)2265 static inline bool owner_on_cpu(struct task_struct *owner)
2266 {
2267 /*
2268 * As lock holder preemption issue, we both skip spinning if
2269 * task is not on cpu or its cpu is preempted
2270 */
2271 return READ_ONCE(owner->on_cpu) && !vcpu_is_preempted(task_cpu(owner));
2272 }
2273
2274 /* Returns effective CPU energy utilization, as seen by the scheduler */
2275 unsigned long sched_cpu_util(int cpu);
2276
2277 #ifdef CONFIG_SCHED_CORE
2278 extern void sched_core_free(struct task_struct *tsk);
2279 extern void sched_core_fork(struct task_struct *p);
2280 extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type,
2281 unsigned long uaddr);
2282 extern int sched_core_idle_cpu(int cpu);
2283 #else
sched_core_free(struct task_struct * tsk)2284 static inline void sched_core_free(struct task_struct *tsk) { }
sched_core_fork(struct task_struct * p)2285 static inline void sched_core_fork(struct task_struct *p) { }
sched_core_idle_cpu(int cpu)2286 static inline int sched_core_idle_cpu(int cpu) { return idle_cpu(cpu); }
2287 #endif
2288
2289 extern void sched_set_stop_task(int cpu, struct task_struct *stop);
2290
2291 #ifdef CONFIG_MEM_ALLOC_PROFILING
alloc_tag_save(struct alloc_tag * tag)2292 static __always_inline struct alloc_tag *alloc_tag_save(struct alloc_tag *tag)
2293 {
2294 swap(current->alloc_tag, tag);
2295 return tag;
2296 }
2297
alloc_tag_restore(struct alloc_tag * tag,struct alloc_tag * old)2298 static __always_inline void alloc_tag_restore(struct alloc_tag *tag, struct alloc_tag *old)
2299 {
2300 #ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG
2301 WARN(current->alloc_tag != tag, "current->alloc_tag was changed:\n");
2302 #endif
2303 current->alloc_tag = old;
2304 }
2305 #else
2306 #define alloc_tag_save(_tag) NULL
2307 #define alloc_tag_restore(_tag, _old) do {} while (0)
2308 #endif
2309
2310 #endif
2311