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/kcov.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/mm_types_task.h>
32 #include <linux/task_io_accounting.h>
33 #include <linux/posix-timers.h>
34 #include <linux/rseq.h>
35 #include <linux/seqlock.h>
36 #include <linux/kcsan.h>
37 #include <linux/sched/rtg.h>
38
39 /* task_struct member predeclarations (sorted alphabetically): */
40 struct audit_context;
41 struct backing_dev_info;
42 struct bio_list;
43 struct blk_plug;
44 struct bpf_run_ctx;
45 struct capture_control;
46 struct cfs_rq;
47 struct fs_struct;
48 struct futex_pi_state;
49 struct io_context;
50 struct mempolicy;
51 struct nameidata;
52 struct nsproxy;
53 struct perf_event_context;
54 struct pid_namespace;
55 struct pipe_inode_info;
56 struct rcu_node;
57 #ifdef CONFIG_RECLAIM_ACCT
58 struct reclaim_acct;
59 #endif
60 struct reclaim_state;
61 struct robust_list_head;
62 struct root_domain;
63 struct rq;
64 struct sched_attr;
65 struct sched_param;
66 struct seq_file;
67 struct sighand_struct;
68 struct signal_struct;
69 struct task_delay_info;
70 struct task_group;
71 struct io_uring_task;
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 0x0000
86 #define TASK_INTERRUPTIBLE 0x0001
87 #define TASK_UNINTERRUPTIBLE 0x0002
88 #define __TASK_STOPPED 0x0004
89 #define __TASK_TRACED 0x0008
90 /* Used in tsk->exit_state: */
91 #define EXIT_DEAD 0x0010
92 #define EXIT_ZOMBIE 0x0020
93 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD)
94 /* Used in tsk->state again: */
95 #define TASK_PARKED 0x0040
96 #define TASK_DEAD 0x0080
97 #define TASK_WAKEKILL 0x0100
98 #define TASK_WAKING 0x0200
99 #define TASK_NOLOAD 0x0400
100 #define TASK_NEW 0x0800
101 #define TASK_STATE_MAX 0x1000
102
103 /* Convenience macros for the sake of set_current_state: */
104 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
105 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED)
106 #define TASK_TRACED (TASK_WAKEKILL | __TASK_TRACED)
107
108 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
109
110 /* Convenience macros for the sake of wake_up(): */
111 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
112
113 /* get_task_state(): */
114 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \
115 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
116 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
117 TASK_PARKED)
118
119 #define task_is_traced(task) ((task->state & __TASK_TRACED) != 0)
120
121 #define task_is_stopped(task) ((task->state & __TASK_STOPPED) != 0)
122
123 #define task_is_stopped_or_traced(task) ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
124
125 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
126
127 /*
128 * Special states are those that do not use the normal wait-loop pattern. See
129 * the comment with set_special_state().
130 */
131 #define is_special_task_state(state) \
132 ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD))
133
134 #define __set_current_state(state_value) \
135 do { \
136 WARN_ON_ONCE(is_special_task_state(state_value));\
137 current->task_state_change = _THIS_IP_; \
138 current->state = (state_value); \
139 } while (0)
140
141 #define set_current_state(state_value) \
142 do { \
143 WARN_ON_ONCE(is_special_task_state(state_value));\
144 current->task_state_change = _THIS_IP_; \
145 smp_store_mb(current->state, (state_value)); \
146 } while (0)
147
148 #define set_special_state(state_value) \
149 do { \
150 unsigned long flags; /* may shadow */ \
151 WARN_ON_ONCE(!is_special_task_state(state_value)); \
152 raw_spin_lock_irqsave(¤t->pi_lock, flags); \
153 current->task_state_change = _THIS_IP_; \
154 current->state = (state_value); \
155 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \
156 } while (0)
157 #else
158 /*
159 * set_current_state() includes a barrier so that the write of current->state
160 * is correctly serialised wrt the caller's subsequent test of whether to
161 * actually sleep:
162 *
163 * for (;;) {
164 * set_current_state(TASK_UNINTERRUPTIBLE);
165 * if (CONDITION)
166 * break;
167 *
168 * schedule();
169 * }
170 * __set_current_state(TASK_RUNNING);
171 *
172 * If the caller does not need such serialisation (because, for instance, the
173 * CONDITION test and condition change and wakeup are under the same lock) then
174 * use __set_current_state().
175 *
176 * The above is typically ordered against the wakeup, which does:
177 *
178 * CONDITION = 1;
179 * wake_up_state(p, TASK_UNINTERRUPTIBLE);
180 *
181 * where wake_up_state()/try_to_wake_up() executes a full memory barrier before
182 * accessing p->state.
183 *
184 * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is,
185 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
186 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
187 *
188 * However, with slightly different timing the wakeup TASK_RUNNING store can
189 * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not
190 * a problem either because that will result in one extra go around the loop
191 * and our @cond test will save the day.
192 *
193 * Also see the comments of try_to_wake_up().
194 */
195 #define __set_current_state(state_value) \
196 current->state = (state_value)
197
198 #define set_current_state(state_value) \
199 smp_store_mb(current->state, (state_value))
200
201 /*
202 * set_special_state() should be used for those states when the blocking task
203 * can not use the regular condition based wait-loop. In that case we must
204 * serialize against wakeups such that any possible in-flight TASK_RUNNING stores
205 * will not collide with our state change.
206 */
207 #define set_special_state(state_value) \
208 do { \
209 unsigned long flags; /* may shadow */ \
210 raw_spin_lock_irqsave(¤t->pi_lock, flags); \
211 current->state = (state_value); \
212 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \
213 } while (0)
214
215 #endif
216
217 /* Task command name length: */
218 #define TASK_COMM_LEN 16
219
220 enum task_event {
221 PUT_PREV_TASK = 0,
222 PICK_NEXT_TASK = 1,
223 TASK_WAKE = 2,
224 TASK_MIGRATE = 3,
225 TASK_UPDATE = 4,
226 IRQ_UPDATE = 5,
227 };
228
229 /* Note: this need to be in sync with migrate_type_names array */
230 enum migrate_types {
231 GROUP_TO_RQ,
232 RQ_TO_GROUP,
233 };
234
235 #ifdef CONFIG_CPU_ISOLATION_OPT
236 extern int sched_isolate_count(const cpumask_t *mask, bool include_offline);
237 extern int sched_isolate_cpu(int cpu);
238 extern int sched_unisolate_cpu(int cpu);
239 extern int sched_unisolate_cpu_unlocked(int cpu);
240 #else
sched_isolate_count(const cpumask_t * mask,bool include_offline)241 static inline int sched_isolate_count(const cpumask_t *mask,
242 bool include_offline)
243 {
244 cpumask_t count_mask;
245
246 if (include_offline)
247 cpumask_andnot(&count_mask, mask, cpu_online_mask);
248 else
249 return 0;
250
251 return cpumask_weight(&count_mask);
252 }
253
sched_isolate_cpu(int cpu)254 static inline int sched_isolate_cpu(int cpu)
255 {
256 return 0;
257 }
258
sched_unisolate_cpu(int cpu)259 static inline int sched_unisolate_cpu(int cpu)
260 {
261 return 0;
262 }
263
sched_unisolate_cpu_unlocked(int cpu)264 static inline int sched_unisolate_cpu_unlocked(int cpu)
265 {
266 return 0;
267 }
268 #endif
269
270 extern void scheduler_tick(void);
271
272 #define MAX_SCHEDULE_TIMEOUT LONG_MAX
273
274 extern long schedule_timeout(long timeout);
275 extern long schedule_timeout_interruptible(long timeout);
276 extern long schedule_timeout_killable(long timeout);
277 extern long schedule_timeout_uninterruptible(long timeout);
278 extern long schedule_timeout_idle(long timeout);
279 asmlinkage void schedule(void);
280 extern void schedule_preempt_disabled(void);
281 asmlinkage void preempt_schedule_irq(void);
282
283 extern int __must_check io_schedule_prepare(void);
284 extern void io_schedule_finish(int token);
285 extern long io_schedule_timeout(long timeout);
286 extern void io_schedule(void);
287
288 /**
289 * struct prev_cputime - snapshot of system and user cputime
290 * @utime: time spent in user mode
291 * @stime: time spent in system mode
292 * @lock: protects the above two fields
293 *
294 * Stores previous user/system time values such that we can guarantee
295 * monotonicity.
296 */
297 struct prev_cputime {
298 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
299 u64 utime;
300 u64 stime;
301 raw_spinlock_t lock;
302 #endif
303 };
304
305 enum vtime_state {
306 /* Task is sleeping or running in a CPU with VTIME inactive: */
307 VTIME_INACTIVE = 0,
308 /* Task is idle */
309 VTIME_IDLE,
310 /* Task runs in kernelspace in a CPU with VTIME active: */
311 VTIME_SYS,
312 /* Task runs in userspace in a CPU with VTIME active: */
313 VTIME_USER,
314 /* Task runs as guests in a CPU with VTIME active: */
315 VTIME_GUEST,
316 };
317
318 struct vtime {
319 seqcount_t seqcount;
320 unsigned long long starttime;
321 enum vtime_state state;
322 unsigned int cpu;
323 u64 utime;
324 u64 stime;
325 u64 gtime;
326 };
327
328 /*
329 * Utilization clamp constraints.
330 * @UCLAMP_MIN: Minimum utilization
331 * @UCLAMP_MAX: Maximum utilization
332 * @UCLAMP_CNT: Utilization clamp constraints count
333 */
334 enum uclamp_id {
335 UCLAMP_MIN = 0,
336 UCLAMP_MAX,
337 UCLAMP_CNT
338 };
339
340 #ifdef CONFIG_SMP
341 extern struct root_domain def_root_domain;
342 extern struct mutex sched_domains_mutex;
343 #endif
344
345 struct sched_info {
346 #ifdef CONFIG_SCHED_INFO
347 /* Cumulative counters: */
348
349 /* # of times we have run on this CPU: */
350 unsigned long pcount;
351
352 /* Time spent waiting on a runqueue: */
353 unsigned long long run_delay;
354
355 /* Timestamps: */
356
357 /* When did we last run on a CPU? */
358 unsigned long long last_arrival;
359
360 /* When were we last queued to run? */
361 unsigned long long last_queued;
362
363 #endif /* CONFIG_SCHED_INFO */
364 };
365
366 /*
367 * Integer metrics need fixed point arithmetic, e.g., sched/fair
368 * has a few: load, load_avg, util_avg, freq, and capacity.
369 *
370 * We define a basic fixed point arithmetic range, and then formalize
371 * all these metrics based on that basic range.
372 */
373 # define SCHED_FIXEDPOINT_SHIFT 10
374 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT)
375
376 /* Increase resolution of cpu_capacity calculations */
377 # define SCHED_CAPACITY_SHIFT SCHED_FIXEDPOINT_SHIFT
378 # define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT)
379
380 struct load_weight {
381 unsigned long weight;
382 u32 inv_weight;
383 };
384
385 /**
386 * struct util_est - Estimation utilization of FAIR tasks
387 * @enqueued: instantaneous estimated utilization of a task/cpu
388 * @ewma: the Exponential Weighted Moving Average (EWMA)
389 * utilization of a task
390 *
391 * Support data structure to track an Exponential Weighted Moving Average
392 * (EWMA) of a FAIR task's utilization. New samples are added to the moving
393 * average each time a task completes an activation. Sample's weight is chosen
394 * so that the EWMA will be relatively insensitive to transient changes to the
395 * task's workload.
396 *
397 * The enqueued attribute has a slightly different meaning for tasks and cpus:
398 * - task: the task's util_avg at last task dequeue time
399 * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU
400 * Thus, the util_est.enqueued of a task represents the contribution on the
401 * estimated utilization of the CPU where that task is currently enqueued.
402 *
403 * Only for tasks we track a moving average of the past instantaneous
404 * estimated utilization. This allows to absorb sporadic drops in utilization
405 * of an otherwise almost periodic task.
406 *
407 * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg
408 * updates. When a task is dequeued, its util_est should not be updated if its
409 * util_avg has not been updated in the meantime.
410 * This information is mapped into the MSB bit of util_est.enqueued at dequeue
411 * time. Since max value of util_est.enqueued for a task is 1024 (PELT util_avg
412 * for a task) it is safe to use MSB.
413 */
414 struct util_est {
415 unsigned int enqueued;
416 unsigned int ewma;
417 #define UTIL_EST_WEIGHT_SHIFT 2
418 #define UTIL_AVG_UNCHANGED 0x80000000
419 } __attribute__((__aligned__(sizeof(u64))));
420
421 /*
422 * The load/runnable/util_avg accumulates an infinite geometric series
423 * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c).
424 *
425 * [load_avg definition]
426 *
427 * load_avg = runnable% * scale_load_down(load)
428 *
429 * [runnable_avg definition]
430 *
431 * runnable_avg = runnable% * SCHED_CAPACITY_SCALE
432 *
433 * [util_avg definition]
434 *
435 * util_avg = running% * SCHED_CAPACITY_SCALE
436 *
437 * where runnable% is the time ratio that a sched_entity is runnable and
438 * running% the time ratio that a sched_entity is running.
439 *
440 * For cfs_rq, they are the aggregated values of all runnable and blocked
441 * sched_entities.
442 *
443 * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU
444 * capacity scaling. The scaling is done through the rq_clock_pelt that is used
445 * for computing those signals (see update_rq_clock_pelt())
446 *
447 * N.B., the above ratios (runnable% and running%) themselves are in the
448 * range of [0, 1]. To do fixed point arithmetics, we therefore scale them
449 * to as large a range as necessary. This is for example reflected by
450 * util_avg's SCHED_CAPACITY_SCALE.
451 *
452 * [Overflow issue]
453 *
454 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
455 * with the highest load (=88761), always runnable on a single cfs_rq,
456 * and should not overflow as the number already hits PID_MAX_LIMIT.
457 *
458 * For all other cases (including 32-bit kernels), struct load_weight's
459 * weight will overflow first before we do, because:
460 *
461 * Max(load_avg) <= Max(load.weight)
462 *
463 * Then it is the load_weight's responsibility to consider overflow
464 * issues.
465 */
466 struct sched_avg {
467 u64 last_update_time;
468 u64 load_sum;
469 u64 runnable_sum;
470 u32 util_sum;
471 u32 period_contrib;
472 unsigned long load_avg;
473 unsigned long runnable_avg;
474 unsigned long util_avg;
475 struct util_est util_est;
476 } ____cacheline_aligned;
477
478 struct sched_statistics {
479 #ifdef CONFIG_SCHEDSTATS
480 u64 wait_start;
481 u64 wait_max;
482 u64 wait_count;
483 u64 wait_sum;
484 u64 iowait_count;
485 u64 iowait_sum;
486
487 u64 sleep_start;
488 u64 sleep_max;
489 s64 sum_sleep_runtime;
490
491 u64 block_start;
492 u64 block_max;
493 u64 exec_max;
494 u64 slice_max;
495
496 u64 nr_migrations_cold;
497 u64 nr_failed_migrations_affine;
498 u64 nr_failed_migrations_running;
499 u64 nr_failed_migrations_hot;
500 u64 nr_forced_migrations;
501
502 u64 nr_wakeups;
503 u64 nr_wakeups_sync;
504 u64 nr_wakeups_migrate;
505 u64 nr_wakeups_local;
506 u64 nr_wakeups_remote;
507 u64 nr_wakeups_affine;
508 u64 nr_wakeups_affine_attempts;
509 u64 nr_wakeups_passive;
510 u64 nr_wakeups_idle;
511 #endif
512 };
513
514 struct sched_entity {
515 /* For load-balancing: */
516 struct load_weight load;
517 struct rb_node run_node;
518 struct list_head group_node;
519 unsigned int on_rq;
520
521 u64 exec_start;
522 u64 sum_exec_runtime;
523 u64 vruntime;
524 u64 prev_sum_exec_runtime;
525
526 u64 nr_migrations;
527
528 struct sched_statistics statistics;
529
530 #ifdef CONFIG_FAIR_GROUP_SCHED
531 int depth;
532 struct sched_entity *parent;
533 /* rq on which this entity is (to be) queued: */
534 struct cfs_rq *cfs_rq;
535 /* rq "owned" by this entity/group: */
536 struct cfs_rq *my_q;
537 /* cached value of my_q->h_nr_running */
538 unsigned long runnable_weight;
539 #endif
540
541 #ifdef CONFIG_SCHED_LATENCY_NICE
542 int latency_weight;
543 #endif
544
545 #ifdef CONFIG_SMP
546 /*
547 * Per entity load average tracking.
548 *
549 * Put into separate cache line so it does not
550 * collide with read-mostly values above.
551 */
552 struct sched_avg avg;
553 #endif
554 };
555
556 #ifdef CONFIG_SCHED_WALT
557 extern void sched_exit(struct task_struct *p);
558 extern int sched_set_init_task_load(struct task_struct *p, int init_load_pct);
559 extern u32 sched_get_init_task_load(struct task_struct *p);
560 extern void free_task_load_ptrs(struct task_struct *p);
561 #define RAVG_HIST_SIZE_MAX 5
562 struct ravg {
563 /*
564 * 'mark_start' marks the beginning of an event (task waking up, task
565 * starting to execute, task being preempted) within a window
566 *
567 * 'sum' represents how runnable a task has been within current
568 * window. It incorporates both running time and wait time and is
569 * frequency scaled.
570 *
571 * 'sum_history' keeps track of history of 'sum' seen over previous
572 * RAVG_HIST_SIZE windows. Windows where task was entirely sleeping are
573 * ignored.
574 *
575 * 'demand' represents maximum sum seen over previous
576 * sysctl_sched_ravg_hist_size windows. 'demand' could drive frequency
577 * demand for tasks.
578 *
579 * 'curr_window_cpu' represents task's contribution to cpu busy time on
580 * various CPUs in the current window
581 *
582 * 'prev_window_cpu' represents task's contribution to cpu busy time on
583 * various CPUs in the previous window
584 *
585 * 'curr_window' represents the sum of all entries in curr_window_cpu
586 *
587 * 'prev_window' represents the sum of all entries in prev_window_cpu
588 *
589 */
590 u64 mark_start;
591 u32 sum, demand;
592 u32 sum_history[RAVG_HIST_SIZE_MAX];
593 u32 *curr_window_cpu, *prev_window_cpu;
594 u32 curr_window, prev_window;
595 u16 active_windows;
596 u16 demand_scaled;
597 };
598 #else
sched_exit(struct task_struct * p)599 static inline void sched_exit(struct task_struct *p) { }
free_task_load_ptrs(struct task_struct * p)600 static inline void free_task_load_ptrs(struct task_struct *p) { }
601 #endif /* CONFIG_SCHED_WALT */
602
603 struct sched_rt_entity {
604 struct list_head run_list;
605 unsigned long timeout;
606 unsigned long watchdog_stamp;
607 unsigned int time_slice;
608 unsigned short on_rq;
609 unsigned short on_list;
610
611 struct sched_rt_entity *back;
612 #ifdef CONFIG_RT_GROUP_SCHED
613 struct sched_rt_entity *parent;
614 /* rq on which this entity is (to be) queued: */
615 struct rt_rq *rt_rq;
616 /* rq "owned" by this entity/group: */
617 struct rt_rq *my_q;
618 #endif
619 } __randomize_layout;
620
621 struct sched_dl_entity {
622 struct rb_node rb_node;
623
624 /*
625 * Original scheduling parameters. Copied here from sched_attr
626 * during sched_setattr(), they will remain the same until
627 * the next sched_setattr().
628 */
629 u64 dl_runtime; /* Maximum runtime for each instance */
630 u64 dl_deadline; /* Relative deadline of each instance */
631 u64 dl_period; /* Separation of two instances (period) */
632 u64 dl_bw; /* dl_runtime / dl_period */
633 u64 dl_density; /* dl_runtime / dl_deadline */
634
635 /*
636 * Actual scheduling parameters. Initialized with the values above,
637 * they are continuously updated during task execution. Note that
638 * the remaining runtime could be < 0 in case we are in overrun.
639 */
640 s64 runtime; /* Remaining runtime for this instance */
641 u64 deadline; /* Absolute deadline for this instance */
642 unsigned int flags; /* Specifying the scheduler behaviour */
643
644 /*
645 * Some bool flags:
646 *
647 * @dl_throttled tells if we exhausted the runtime. If so, the
648 * task has to wait for a replenishment to be performed at the
649 * next firing of dl_timer.
650 *
651 * @dl_boosted tells if we are boosted due to DI. If so we are
652 * outside bandwidth enforcement mechanism (but only until we
653 * exit the critical section);
654 *
655 * @dl_yielded tells if task gave up the CPU before consuming
656 * all its available runtime during the last job.
657 *
658 * @dl_non_contending tells if the task is inactive while still
659 * contributing to the active utilization. In other words, it
660 * indicates if the inactive timer has been armed and its handler
661 * has not been executed yet. This flag is useful to avoid race
662 * conditions between the inactive timer handler and the wakeup
663 * code.
664 *
665 * @dl_overrun tells if the task asked to be informed about runtime
666 * overruns.
667 */
668 unsigned int dl_throttled : 1;
669 unsigned int dl_yielded : 1;
670 unsigned int dl_non_contending : 1;
671 unsigned int dl_overrun : 1;
672
673 /*
674 * Bandwidth enforcement timer. Each -deadline task has its
675 * own bandwidth to be enforced, thus we need one timer per task.
676 */
677 struct hrtimer dl_timer;
678
679 /*
680 * Inactive timer, responsible for decreasing the active utilization
681 * at the "0-lag time". When a -deadline task blocks, it contributes
682 * to GRUB's active utilization until the "0-lag time", hence a
683 * timer is needed to decrease the active utilization at the correct
684 * time.
685 */
686 struct hrtimer inactive_timer;
687
688 #ifdef CONFIG_RT_MUTEXES
689 /*
690 * Priority Inheritance. When a DEADLINE scheduling entity is boosted
691 * pi_se points to the donor, otherwise points to the dl_se it belongs
692 * to (the original one/itself).
693 */
694 struct sched_dl_entity *pi_se;
695 #endif
696 };
697
698 #ifdef CONFIG_UCLAMP_TASK
699 /* Number of utilization clamp buckets (shorter alias) */
700 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT
701
702 /*
703 * Utilization clamp for a scheduling entity
704 * @value: clamp value "assigned" to a se
705 * @bucket_id: bucket index corresponding to the "assigned" value
706 * @active: the se is currently refcounted in a rq's bucket
707 * @user_defined: the requested clamp value comes from user-space
708 *
709 * The bucket_id is the index of the clamp bucket matching the clamp value
710 * which is pre-computed and stored to avoid expensive integer divisions from
711 * the fast path.
712 *
713 * The active bit is set whenever a task has got an "effective" value assigned,
714 * which can be different from the clamp value "requested" from user-space.
715 * This allows to know a task is refcounted in the rq's bucket corresponding
716 * to the "effective" bucket_id.
717 *
718 * The user_defined bit is set whenever a task has got a task-specific clamp
719 * value requested from userspace, i.e. the system defaults apply to this task
720 * just as a restriction. This allows to relax default clamps when a less
721 * restrictive task-specific value has been requested, thus allowing to
722 * implement a "nice" semantic. For example, a task running with a 20%
723 * default boost can still drop its own boosting to 0%.
724 */
725 struct uclamp_se {
726 unsigned int value : bits_per(SCHED_CAPACITY_SCALE);
727 unsigned int bucket_id : bits_per(UCLAMP_BUCKETS);
728 unsigned int active : 1;
729 unsigned int user_defined : 1;
730 };
731 #endif /* CONFIG_UCLAMP_TASK */
732
733 union rcu_special {
734 struct {
735 u8 blocked;
736 u8 need_qs;
737 u8 exp_hint; /* Hint for performance. */
738 u8 need_mb; /* Readers need smp_mb(). */
739 } b; /* Bits. */
740 u32 s; /* Set of bits. */
741 };
742
743 enum perf_event_task_context {
744 perf_invalid_context = -1,
745 perf_hw_context = 0,
746 perf_sw_context,
747 perf_nr_task_contexts,
748 };
749
750 struct wake_q_node {
751 struct wake_q_node *next;
752 };
753
754 struct task_struct {
755 #ifdef CONFIG_THREAD_INFO_IN_TASK
756 /*
757 * For reasons of header soup (see current_thread_info()), this
758 * must be the first element of task_struct.
759 */
760 struct thread_info thread_info;
761 #endif
762 /* -1 unrunnable, 0 runnable, >0 stopped: */
763 volatile long state;
764
765 /*
766 * This begins the randomizable portion of task_struct. Only
767 * scheduling-critical items should be added above here.
768 */
769 randomized_struct_fields_start
770
771 void *stack;
772 refcount_t usage;
773 /* Per task flags (PF_*), defined further below: */
774 unsigned int flags;
775 unsigned int ptrace;
776
777 #ifdef CONFIG_SMP
778 int on_cpu;
779 struct __call_single_node wake_entry;
780 #ifdef CONFIG_THREAD_INFO_IN_TASK
781 /* Current CPU: */
782 unsigned int cpu;
783 #endif
784 unsigned int wakee_flips;
785 unsigned long wakee_flip_decay_ts;
786 struct task_struct *last_wakee;
787
788 /*
789 * recent_used_cpu is initially set as the last CPU used by a task
790 * that wakes affine another task. Waker/wakee relationships can
791 * push tasks around a CPU where each wakeup moves to the next one.
792 * Tracking a recently used CPU allows a quick search for a recently
793 * used CPU that may be idle.
794 */
795 int recent_used_cpu;
796 int wake_cpu;
797 #endif
798 int on_rq;
799
800 int prio;
801 int static_prio;
802 int normal_prio;
803 unsigned int rt_priority;
804 #ifdef CONFIG_SCHED_LATENCY_NICE
805 int latency_prio;
806 #endif
807
808 const struct sched_class *sched_class;
809 struct sched_entity se;
810 struct sched_rt_entity rt;
811 #ifdef CONFIG_SCHED_WALT
812 struct ravg ravg;
813 /*
814 * 'init_load_pct' represents the initial task load assigned to children
815 * of this task
816 */
817 u32 init_load_pct;
818 u64 last_sleep_ts;
819 #endif
820
821 #ifdef CONFIG_SCHED_RTG
822 int rtg_depth;
823 struct related_thread_group *grp;
824 struct list_head grp_list;
825 #endif
826
827 #ifdef CONFIG_CGROUP_SCHED
828 struct task_group *sched_task_group;
829 #endif
830 struct sched_dl_entity dl;
831
832 #ifdef CONFIG_UCLAMP_TASK
833 /*
834 * Clamp values requested for a scheduling entity.
835 * Must be updated with task_rq_lock() held.
836 */
837 struct uclamp_se uclamp_req[UCLAMP_CNT];
838 /*
839 * Effective clamp values used for a scheduling entity.
840 * Must be updated with task_rq_lock() held.
841 */
842 struct uclamp_se uclamp[UCLAMP_CNT];
843 #endif
844
845 #ifdef CONFIG_PREEMPT_NOTIFIERS
846 /* List of struct preempt_notifier: */
847 struct hlist_head preempt_notifiers;
848 #endif
849
850 #ifdef CONFIG_BLK_DEV_IO_TRACE
851 unsigned int btrace_seq;
852 #endif
853
854 unsigned int policy;
855 int nr_cpus_allowed;
856 const cpumask_t *cpus_ptr;
857 cpumask_t cpus_mask;
858
859 #ifdef CONFIG_PREEMPT_RCU
860 int rcu_read_lock_nesting;
861 union rcu_special rcu_read_unlock_special;
862 struct list_head rcu_node_entry;
863 struct rcu_node *rcu_blocked_node;
864 #endif /* #ifdef CONFIG_PREEMPT_RCU */
865
866 #ifdef CONFIG_TASKS_RCU
867 unsigned long rcu_tasks_nvcsw;
868 u8 rcu_tasks_holdout;
869 u8 rcu_tasks_idx;
870 int rcu_tasks_idle_cpu;
871 struct list_head rcu_tasks_holdout_list;
872 #endif /* #ifdef CONFIG_TASKS_RCU */
873
874 #ifdef CONFIG_TASKS_TRACE_RCU
875 int trc_reader_nesting;
876 int trc_ipi_to_cpu;
877 union rcu_special trc_reader_special;
878 bool trc_reader_checked;
879 struct list_head trc_holdout_list;
880 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
881
882 struct sched_info sched_info;
883
884 struct list_head tasks;
885 #ifdef CONFIG_SMP
886 struct plist_node pushable_tasks;
887 struct rb_node pushable_dl_tasks;
888 #endif
889
890 struct mm_struct *mm;
891 struct mm_struct *active_mm;
892
893 /* Per-thread vma caching: */
894 struct vmacache vmacache;
895
896 #ifdef SPLIT_RSS_COUNTING
897 struct task_rss_stat rss_stat;
898 #endif
899 int exit_state;
900 int exit_code;
901 int exit_signal;
902 /* The signal sent when the parent dies: */
903 int pdeath_signal;
904 /* JOBCTL_*, siglock protected: */
905 unsigned long jobctl;
906
907 /* Used for emulating ABI behavior of previous Linux versions: */
908 unsigned int personality;
909
910 /* Scheduler bits, serialized by scheduler locks: */
911 unsigned sched_reset_on_fork:1;
912 unsigned sched_contributes_to_load:1;
913 unsigned sched_migrated:1;
914 #ifdef CONFIG_PSI
915 unsigned sched_psi_wake_requeue:1;
916 #endif
917
918 /* Force alignment to the next boundary: */
919 unsigned :0;
920
921 /* Unserialized, strictly 'current' */
922
923 /*
924 * This field must not be in the scheduler word above due to wakelist
925 * queueing no longer being serialized by p->on_cpu. However:
926 *
927 * p->XXX = X; ttwu()
928 * schedule() if (p->on_rq && ..) // false
929 * smp_mb__after_spinlock(); if (smp_load_acquire(&p->on_cpu) && //true
930 * deactivate_task() ttwu_queue_wakelist())
931 * p->on_rq = 0; p->sched_remote_wakeup = Y;
932 *
933 * guarantees all stores of 'current' are visible before
934 * ->sched_remote_wakeup gets used, so it can be in this word.
935 */
936 unsigned sched_remote_wakeup:1;
937
938 /* Bit to tell LSMs we're in execve(): */
939 unsigned in_execve:1;
940 unsigned in_iowait:1;
941 #ifndef TIF_RESTORE_SIGMASK
942 unsigned restore_sigmask:1;
943 #endif
944 #ifdef CONFIG_MEMCG
945 unsigned in_user_fault:1;
946 #endif
947 #ifdef CONFIG_COMPAT_BRK
948 unsigned brk_randomized:1;
949 #endif
950 #ifdef CONFIG_CGROUPS
951 /* disallow userland-initiated cgroup migration */
952 unsigned no_cgroup_migration:1;
953 /* task is frozen/stopped (used by the cgroup freezer) */
954 unsigned frozen:1;
955 #endif
956 #ifdef CONFIG_BLK_CGROUP
957 unsigned use_memdelay:1;
958 #endif
959 #ifdef CONFIG_PSI
960 /* Stalled due to lack of memory */
961 unsigned in_memstall:1;
962 #endif
963
964 unsigned long atomic_flags; /* Flags requiring atomic access. */
965
966 struct restart_block restart_block;
967
968 pid_t pid;
969 pid_t tgid;
970
971 #ifdef CONFIG_STACKPROTECTOR
972 /* Canary value for the -fstack-protector GCC feature: */
973 unsigned long stack_canary;
974 #endif
975 /*
976 * Pointers to the (original) parent process, youngest child, younger sibling,
977 * older sibling, respectively. (p->father can be replaced with
978 * p->real_parent->pid)
979 */
980
981 /* Real parent process: */
982 struct task_struct __rcu *real_parent;
983
984 /* Recipient of SIGCHLD, wait4() reports: */
985 struct task_struct __rcu *parent;
986
987 /*
988 * Children/sibling form the list of natural children:
989 */
990 struct list_head children;
991 struct list_head sibling;
992 struct task_struct *group_leader;
993
994 /*
995 * 'ptraced' is the list of tasks this task is using ptrace() on.
996 *
997 * This includes both natural children and PTRACE_ATTACH targets.
998 * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
999 */
1000 struct list_head ptraced;
1001 struct list_head ptrace_entry;
1002
1003 /* PID/PID hash table linkage. */
1004 struct pid *thread_pid;
1005 struct hlist_node pid_links[PIDTYPE_MAX];
1006 struct list_head thread_group;
1007 struct list_head thread_node;
1008
1009 struct completion *vfork_done;
1010
1011 /* CLONE_CHILD_SETTID: */
1012 int __user *set_child_tid;
1013
1014 /* CLONE_CHILD_CLEARTID: */
1015 int __user *clear_child_tid;
1016
1017 u64 utime;
1018 u64 stime;
1019 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
1020 u64 utimescaled;
1021 u64 stimescaled;
1022 #endif
1023 u64 gtime;
1024 struct prev_cputime prev_cputime;
1025 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1026 struct vtime vtime;
1027 #endif
1028
1029 #ifdef CONFIG_NO_HZ_FULL
1030 atomic_t tick_dep_mask;
1031 #endif
1032 /* Context switch counts: */
1033 unsigned long nvcsw;
1034 unsigned long nivcsw;
1035
1036 /* Monotonic time in nsecs: */
1037 u64 start_time;
1038
1039 /* Boot based time in nsecs: */
1040 u64 start_boottime;
1041
1042 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
1043 unsigned long min_flt;
1044 unsigned long maj_flt;
1045
1046 /* Empty if CONFIG_POSIX_CPUTIMERS=n */
1047 struct posix_cputimers posix_cputimers;
1048
1049 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK
1050 struct posix_cputimers_work posix_cputimers_work;
1051 #endif
1052
1053 /* Process credentials: */
1054
1055 /* Tracer's credentials at attach: */
1056 const struct cred __rcu *ptracer_cred;
1057
1058 /* Objective and real subjective task credentials (COW): */
1059 const struct cred __rcu *real_cred;
1060
1061 /* Effective (overridable) subjective task credentials (COW): */
1062 const struct cred __rcu *cred;
1063
1064 #ifdef CONFIG_KEYS
1065 /* Cached requested key. */
1066 struct key *cached_requested_key;
1067 #endif
1068
1069 /*
1070 * executable name, excluding path.
1071 *
1072 * - normally initialized setup_new_exec()
1073 * - access it with [gs]et_task_comm()
1074 * - lock it with task_lock()
1075 */
1076 char comm[TASK_COMM_LEN];
1077
1078 struct nameidata *nameidata;
1079
1080 #ifdef CONFIG_SYSVIPC
1081 struct sysv_sem sysvsem;
1082 struct sysv_shm sysvshm;
1083 #endif
1084 #ifdef CONFIG_DETECT_HUNG_TASK
1085 unsigned long last_switch_count;
1086 unsigned long last_switch_time;
1087 #endif
1088 /* Filesystem information: */
1089 struct fs_struct *fs;
1090
1091 /* Open file information: */
1092 struct files_struct *files;
1093
1094 #ifdef CONFIG_IO_URING
1095 struct io_uring_task *io_uring;
1096 #endif
1097
1098 /* Namespaces: */
1099 struct nsproxy *nsproxy;
1100
1101 /* Signal handlers: */
1102 struct signal_struct *signal;
1103 struct sighand_struct __rcu *sighand;
1104 sigset_t blocked;
1105 sigset_t real_blocked;
1106 /* Restored if set_restore_sigmask() was used: */
1107 sigset_t saved_sigmask;
1108 struct sigpending pending;
1109 unsigned long sas_ss_sp;
1110 size_t sas_ss_size;
1111 unsigned int sas_ss_flags;
1112
1113 struct callback_head *task_works;
1114
1115 #ifdef CONFIG_AUDIT
1116 #ifdef CONFIG_AUDITSYSCALL
1117 struct audit_context *audit_context;
1118 #endif
1119 kuid_t loginuid;
1120 unsigned int sessionid;
1121 #endif
1122 struct seccomp seccomp;
1123
1124 /* Thread group tracking: */
1125 u64 parent_exec_id;
1126 u64 self_exec_id;
1127
1128 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
1129 spinlock_t alloc_lock;
1130
1131 /* Protection of the PI data structures: */
1132 raw_spinlock_t pi_lock;
1133
1134 struct wake_q_node wake_q;
1135
1136 #ifdef CONFIG_RT_MUTEXES
1137 /* PI waiters blocked on a rt_mutex held by this task: */
1138 struct rb_root_cached pi_waiters;
1139 /* Updated under owner's pi_lock and rq lock */
1140 struct task_struct *pi_top_task;
1141 /* Deadlock detection and priority inheritance handling: */
1142 struct rt_mutex_waiter *pi_blocked_on;
1143 #endif
1144
1145 #ifdef CONFIG_DEBUG_MUTEXES
1146 /* Mutex deadlock detection: */
1147 struct mutex_waiter *blocked_on;
1148 #endif
1149
1150 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1151 int non_block_count;
1152 #endif
1153
1154 #ifdef CONFIG_TRACE_IRQFLAGS
1155 struct irqtrace_events irqtrace;
1156 unsigned int hardirq_threaded;
1157 u64 hardirq_chain_key;
1158 int softirqs_enabled;
1159 int softirq_context;
1160 int irq_config;
1161 #endif
1162
1163 #ifdef CONFIG_LOCKDEP
1164 # define MAX_LOCK_DEPTH 48UL
1165 u64 curr_chain_key;
1166 int lockdep_depth;
1167 unsigned int lockdep_recursion;
1168 struct held_lock held_locks[MAX_LOCK_DEPTH];
1169 #endif
1170
1171 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP)
1172 unsigned int in_ubsan;
1173 #endif
1174
1175 /* Journalling filesystem info: */
1176 void *journal_info;
1177
1178 /* Stacked block device info: */
1179 struct bio_list *bio_list;
1180
1181 #ifdef CONFIG_BLOCK
1182 /* Stack plugging: */
1183 struct blk_plug *plug;
1184 #endif
1185
1186 /* VM state: */
1187 struct reclaim_state *reclaim_state;
1188
1189 struct backing_dev_info *backing_dev_info;
1190
1191 struct io_context *io_context;
1192
1193 #ifdef CONFIG_COMPACTION
1194 struct capture_control *capture_control;
1195 #endif
1196 /* Ptrace state: */
1197 unsigned long ptrace_message;
1198 kernel_siginfo_t *last_siginfo;
1199
1200 struct task_io_accounting ioac;
1201 #ifdef CONFIG_PSI
1202 /* Pressure stall state */
1203 unsigned int psi_flags;
1204 #endif
1205 #ifdef CONFIG_TASK_XACCT
1206 /* Accumulated RSS usage: */
1207 u64 acct_rss_mem1;
1208 /* Accumulated virtual memory usage: */
1209 u64 acct_vm_mem1;
1210 /* stime + utime since last update: */
1211 u64 acct_timexpd;
1212 #endif
1213 #ifdef CONFIG_CPUSETS
1214 /* Protected by ->alloc_lock: */
1215 nodemask_t mems_allowed;
1216 /* Seqence number to catch updates: */
1217 seqcount_spinlock_t mems_allowed_seq;
1218 int cpuset_mem_spread_rotor;
1219 int cpuset_slab_spread_rotor;
1220 #endif
1221 #ifdef CONFIG_CGROUPS
1222 /* Control Group info protected by css_set_lock: */
1223 struct css_set __rcu *cgroups;
1224 /* cg_list protected by css_set_lock and tsk->alloc_lock: */
1225 struct list_head cg_list;
1226 #endif
1227 #ifdef CONFIG_X86_CPU_RESCTRL
1228 u32 closid;
1229 u32 rmid;
1230 #endif
1231 #ifdef CONFIG_FUTEX
1232 struct robust_list_head __user *robust_list;
1233 #ifdef CONFIG_COMPAT
1234 struct compat_robust_list_head __user *compat_robust_list;
1235 #endif
1236 struct list_head pi_state_list;
1237 struct futex_pi_state *pi_state_cache;
1238 struct mutex futex_exit_mutex;
1239 unsigned int futex_state;
1240 #endif
1241 #ifdef CONFIG_PERF_EVENTS
1242 struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1243 struct mutex perf_event_mutex;
1244 struct list_head perf_event_list;
1245 #endif
1246 #ifdef CONFIG_DEBUG_PREEMPT
1247 unsigned long preempt_disable_ip;
1248 #endif
1249 #ifdef CONFIG_NUMA
1250 /* Protected by alloc_lock: */
1251 struct mempolicy *mempolicy;
1252 short il_prev;
1253 short pref_node_fork;
1254 #endif
1255 #ifdef CONFIG_NUMA_BALANCING
1256 int numa_scan_seq;
1257 unsigned int numa_scan_period;
1258 unsigned int numa_scan_period_max;
1259 int numa_preferred_nid;
1260 unsigned long numa_migrate_retry;
1261 /* Migration stamp: */
1262 u64 node_stamp;
1263 u64 last_task_numa_placement;
1264 u64 last_sum_exec_runtime;
1265 struct callback_head numa_work;
1266
1267 /*
1268 * This pointer is only modified for current in syscall and
1269 * pagefault context (and for tasks being destroyed), so it can be read
1270 * from any of the following contexts:
1271 * - RCU read-side critical section
1272 * - current->numa_group from everywhere
1273 * - task's runqueue locked, task not running
1274 */
1275 struct numa_group __rcu *numa_group;
1276
1277 /*
1278 * numa_faults is an array split into four regions:
1279 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1280 * in this precise order.
1281 *
1282 * faults_memory: Exponential decaying average of faults on a per-node
1283 * basis. Scheduling placement decisions are made based on these
1284 * counts. The values remain static for the duration of a PTE scan.
1285 * faults_cpu: Track the nodes the process was running on when a NUMA
1286 * hinting fault was incurred.
1287 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1288 * during the current scan window. When the scan completes, the counts
1289 * in faults_memory and faults_cpu decay and these values are copied.
1290 */
1291 unsigned long *numa_faults;
1292 unsigned long total_numa_faults;
1293
1294 /*
1295 * numa_faults_locality tracks if faults recorded during the last
1296 * scan window were remote/local or failed to migrate. The task scan
1297 * period is adapted based on the locality of the faults with different
1298 * weights depending on whether they were shared or private faults
1299 */
1300 unsigned long numa_faults_locality[3];
1301
1302 unsigned long numa_pages_migrated;
1303 #endif /* CONFIG_NUMA_BALANCING */
1304
1305 #ifdef CONFIG_RSEQ
1306 struct rseq __user *rseq;
1307 u32 rseq_sig;
1308 /*
1309 * RmW on rseq_event_mask must be performed atomically
1310 * with respect to preemption.
1311 */
1312 unsigned long rseq_event_mask;
1313 #endif
1314
1315 struct tlbflush_unmap_batch tlb_ubc;
1316
1317 union {
1318 refcount_t rcu_users;
1319 struct rcu_head rcu;
1320 };
1321
1322 /* Cache last used pipe for splice(): */
1323 struct pipe_inode_info *splice_pipe;
1324
1325 struct page_frag task_frag;
1326
1327 #ifdef CONFIG_TASK_DELAY_ACCT
1328 struct task_delay_info *delays;
1329 #endif
1330
1331 #ifdef CONFIG_RECLAIM_ACCT
1332 struct reclaim_acct *reclaim_acct;
1333 #endif
1334
1335 #ifdef CONFIG_FAULT_INJECTION
1336 int make_it_fail;
1337 unsigned int fail_nth;
1338 #endif
1339 /*
1340 * When (nr_dirtied >= nr_dirtied_pause), it's time to call
1341 * balance_dirty_pages() for a dirty throttling pause:
1342 */
1343 int nr_dirtied;
1344 int nr_dirtied_pause;
1345 /* Start of a write-and-pause period: */
1346 unsigned long dirty_paused_when;
1347
1348 #ifdef CONFIG_LATENCYTOP
1349 int latency_record_count;
1350 struct latency_record latency_record[LT_SAVECOUNT];
1351 #endif
1352 /*
1353 * Time slack values; these are used to round up poll() and
1354 * select() etc timeout values. These are in nanoseconds.
1355 */
1356 u64 timer_slack_ns;
1357 u64 default_timer_slack_ns;
1358
1359 #ifdef CONFIG_KASAN
1360 unsigned int kasan_depth;
1361 #endif
1362
1363 #ifdef CONFIG_KCSAN
1364 struct kcsan_ctx kcsan_ctx;
1365 #ifdef CONFIG_TRACE_IRQFLAGS
1366 struct irqtrace_events kcsan_save_irqtrace;
1367 #endif
1368 #endif
1369
1370 #if IS_ENABLED(CONFIG_KUNIT)
1371 struct kunit *kunit_test;
1372 #endif
1373
1374 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1375 /* Index of current stored address in ret_stack: */
1376 int curr_ret_stack;
1377 int curr_ret_depth;
1378
1379 /* Stack of return addresses for return function tracing: */
1380 struct ftrace_ret_stack *ret_stack;
1381
1382 /* Timestamp for last schedule: */
1383 unsigned long long ftrace_timestamp;
1384
1385 /*
1386 * Number of functions that haven't been traced
1387 * because of depth overrun:
1388 */
1389 atomic_t trace_overrun;
1390
1391 /* Pause tracing: */
1392 atomic_t tracing_graph_pause;
1393 #endif
1394
1395 #ifdef CONFIG_TRACING
1396 /* State flags for use by tracers: */
1397 unsigned long trace;
1398
1399 /* Bitmask and counter of trace recursion: */
1400 unsigned long trace_recursion;
1401 #endif /* CONFIG_TRACING */
1402
1403 #ifdef CONFIG_KCOV
1404 /* See kernel/kcov.c for more details. */
1405
1406 /* Coverage collection mode enabled for this task (0 if disabled): */
1407 unsigned int kcov_mode;
1408
1409 /* Size of the kcov_area: */
1410 unsigned int kcov_size;
1411
1412 /* Buffer for coverage collection: */
1413 void *kcov_area;
1414
1415 /* KCOV descriptor wired with this task or NULL: */
1416 struct kcov *kcov;
1417
1418 /* KCOV common handle for remote coverage collection: */
1419 u64 kcov_handle;
1420
1421 /* KCOV sequence number: */
1422 int kcov_sequence;
1423
1424 /* Collect coverage from softirq context: */
1425 unsigned int kcov_softirq;
1426 #endif
1427
1428 #ifdef CONFIG_MEMCG
1429 struct mem_cgroup *memcg_in_oom;
1430 gfp_t memcg_oom_gfp_mask;
1431 int memcg_oom_order;
1432
1433 /* Number of pages to reclaim on returning to userland: */
1434 unsigned int memcg_nr_pages_over_high;
1435
1436 /* Used by memcontrol for targeted memcg charge: */
1437 struct mem_cgroup *active_memcg;
1438 #endif
1439
1440 #ifdef CONFIG_BLK_CGROUP
1441 struct request_queue *throttle_queue;
1442 #endif
1443
1444 #ifdef CONFIG_UPROBES
1445 struct uprobe_task *utask;
1446 #endif
1447 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1448 unsigned int sequential_io;
1449 unsigned int sequential_io_avg;
1450 #endif
1451 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1452 unsigned long task_state_change;
1453 #endif
1454 int pagefault_disabled;
1455 #ifdef CONFIG_MMU
1456 struct task_struct *oom_reaper_list;
1457 #endif
1458 #ifdef CONFIG_VMAP_STACK
1459 struct vm_struct *stack_vm_area;
1460 #endif
1461 #ifdef CONFIG_THREAD_INFO_IN_TASK
1462 /* A live task holds one reference: */
1463 refcount_t stack_refcount;
1464 #endif
1465 #ifdef CONFIG_LIVEPATCH
1466 int patch_state;
1467 #endif
1468 #ifdef CONFIG_SECURITY
1469 /* Used by LSM modules for access restriction: */
1470 void *security;
1471 #endif
1472 #ifdef CONFIG_BPF_SYSCALL
1473 /* Used for BPF run context */
1474 struct bpf_run_ctx *bpf_ctx;
1475 #endif
1476
1477 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK
1478 unsigned long lowest_stack;
1479 unsigned long prev_lowest_stack;
1480 #endif
1481
1482 #ifdef CONFIG_X86_MCE
1483 void __user *mce_vaddr;
1484 __u64 mce_kflags;
1485 u64 mce_addr;
1486 __u64 mce_ripv : 1,
1487 mce_whole_page : 1,
1488 __mce_reserved : 62;
1489 struct callback_head mce_kill_me;
1490 int mce_count;
1491 #endif
1492
1493 #ifdef CONFIG_ACCESS_TOKENID
1494 u64 token;
1495 u64 ftoken;
1496 #endif
1497 /*
1498 * New fields for task_struct should be added above here, so that
1499 * they are included in the randomized portion of task_struct.
1500 */
1501 randomized_struct_fields_end
1502
1503 /* CPU-specific state of this task: */
1504 struct thread_struct thread;
1505
1506 /*
1507 * WARNING: on x86, 'thread_struct' contains a variable-sized
1508 * structure. It *MUST* be at the end of 'task_struct'.
1509 *
1510 * Do not put anything below here!
1511 */
1512 };
1513
task_pid(struct task_struct * task)1514 static inline struct pid *task_pid(struct task_struct *task)
1515 {
1516 return task->thread_pid;
1517 }
1518
1519 /*
1520 * the helpers to get the task's different pids as they are seen
1521 * from various namespaces
1522 *
1523 * task_xid_nr() : global id, i.e. the id seen from the init namespace;
1524 * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of
1525 * current.
1526 * task_xid_nr_ns() : id seen from the ns specified;
1527 *
1528 * see also pid_nr() etc in include/linux/pid.h
1529 */
1530 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns);
1531
task_pid_nr(struct task_struct * tsk)1532 static inline pid_t task_pid_nr(struct task_struct *tsk)
1533 {
1534 return tsk->pid;
1535 }
1536
task_pid_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1537 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1538 {
1539 return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1540 }
1541
task_pid_vnr(struct task_struct * tsk)1542 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1543 {
1544 return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1545 }
1546
1547
task_tgid_nr(struct task_struct * tsk)1548 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1549 {
1550 return tsk->tgid;
1551 }
1552
1553 /**
1554 * pid_alive - check that a task structure is not stale
1555 * @p: Task structure to be checked.
1556 *
1557 * Test if a process is not yet dead (at most zombie state)
1558 * If pid_alive fails, then pointers within the task structure
1559 * can be stale and must not be dereferenced.
1560 *
1561 * Return: 1 if the process is alive. 0 otherwise.
1562 */
pid_alive(const struct task_struct * p)1563 static inline int pid_alive(const struct task_struct *p)
1564 {
1565 return p->thread_pid != NULL;
1566 }
1567
task_pgrp_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1568 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1569 {
1570 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1571 }
1572
task_pgrp_vnr(struct task_struct * tsk)1573 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1574 {
1575 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1576 }
1577
1578
task_session_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1579 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1580 {
1581 return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1582 }
1583
task_session_vnr(struct task_struct * tsk)1584 static inline pid_t task_session_vnr(struct task_struct *tsk)
1585 {
1586 return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1587 }
1588
task_tgid_nr_ns(struct task_struct * tsk,struct pid_namespace * ns)1589 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1590 {
1591 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, ns);
1592 }
1593
task_tgid_vnr(struct task_struct * tsk)1594 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1595 {
1596 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, NULL);
1597 }
1598
task_ppid_nr_ns(const struct task_struct * tsk,struct pid_namespace * ns)1599 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1600 {
1601 pid_t pid = 0;
1602
1603 rcu_read_lock();
1604 if (pid_alive(tsk))
1605 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1606 rcu_read_unlock();
1607
1608 return pid;
1609 }
1610
task_ppid_nr(const struct task_struct * tsk)1611 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1612 {
1613 return task_ppid_nr_ns(tsk, &init_pid_ns);
1614 }
1615
1616 /* Obsolete, do not use: */
task_pgrp_nr(struct task_struct * tsk)1617 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1618 {
1619 return task_pgrp_nr_ns(tsk, &init_pid_ns);
1620 }
1621
1622 #define TASK_REPORT_IDLE (TASK_REPORT + 1)
1623 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1)
1624
task_state_index(struct task_struct * tsk)1625 static inline unsigned int task_state_index(struct task_struct *tsk)
1626 {
1627 unsigned int tsk_state = READ_ONCE(tsk->state);
1628 unsigned int state = (tsk_state | tsk->exit_state) & TASK_REPORT;
1629
1630 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX);
1631
1632 if (tsk_state == TASK_IDLE)
1633 state = TASK_REPORT_IDLE;
1634
1635 return fls(state);
1636 }
1637
task_index_to_char(unsigned int state)1638 static inline char task_index_to_char(unsigned int state)
1639 {
1640 static const char state_char[] = "RSDTtXZPI";
1641
1642 BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1);
1643
1644 return state_char[state];
1645 }
1646
task_state_to_char(struct task_struct * tsk)1647 static inline char task_state_to_char(struct task_struct *tsk)
1648 {
1649 return task_index_to_char(task_state_index(tsk));
1650 }
1651
1652 /**
1653 * is_global_init - check if a task structure is init. Since init
1654 * is free to have sub-threads we need to check tgid.
1655 * @tsk: Task structure to be checked.
1656 *
1657 * Check if a task structure is the first user space task the kernel created.
1658 *
1659 * Return: 1 if the task structure is init. 0 otherwise.
1660 */
is_global_init(struct task_struct * tsk)1661 static inline int is_global_init(struct task_struct *tsk)
1662 {
1663 return task_tgid_nr(tsk) == 1;
1664 }
1665
1666 extern struct pid *cad_pid;
1667
1668 /*
1669 * Per process flags
1670 */
1671 #define PF_VCPU 0x00000001 /* I'm a virtual CPU */
1672 #define PF_IDLE 0x00000002 /* I am an IDLE thread */
1673 #define PF_EXITING 0x00000004 /* Getting shut down */
1674 #define PF_IO_WORKER 0x00000010 /* Task is an IO worker */
1675 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */
1676 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */
1677 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */
1678 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */
1679 #define PF_DUMPCORE 0x00000200 /* Dumped core */
1680 #define PF_SIGNALED 0x00000400 /* Killed by a signal */
1681 #define PF_MEMALLOC 0x00000800 /* Allocating memory */
1682 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */
1683 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */
1684 #define PF_USED_ASYNC 0x00004000 /* Used async_schedule*(), used by module init */
1685 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */
1686 #define PF_FROZEN 0x00010000 /* Frozen for system suspend */
1687 #define PF_KSWAPD 0x00020000 /* I am kswapd */
1688 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocation requests will inherit GFP_NOFS */
1689 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocation requests will inherit GFP_NOIO */
1690 #define PF_LOCAL_THROTTLE 0x00100000 /* Throttle writes only against the bdi I write to,
1691 * I am cleaning dirty pages from some other bdi. */
1692 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */
1693 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */
1694 #define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */
1695 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */
1696 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */
1697 #define PF_MEMALLOC_NOCMA 0x10000000 /* All allocation request will have _GFP_MOVABLE cleared */
1698 #define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezable */
1699 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */
1700
1701 /*
1702 * Only the _current_ task can read/write to tsk->flags, but other
1703 * tasks can access tsk->flags in readonly mode for example
1704 * with tsk_used_math (like during threaded core dumping).
1705 * There is however an exception to this rule during ptrace
1706 * or during fork: the ptracer task is allowed to write to the
1707 * child->flags of its traced child (same goes for fork, the parent
1708 * can write to the child->flags), because we're guaranteed the
1709 * child is not running and in turn not changing child->flags
1710 * at the same time the parent does it.
1711 */
1712 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1713 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1714 #define clear_used_math() clear_stopped_child_used_math(current)
1715 #define set_used_math() set_stopped_child_used_math(current)
1716
1717 #define conditional_stopped_child_used_math(condition, child) \
1718 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1719
1720 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current)
1721
1722 #define copy_to_stopped_child_used_math(child) \
1723 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1724
1725 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1726 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1727 #define used_math() tsk_used_math(current)
1728
is_percpu_thread(void)1729 static __always_inline bool is_percpu_thread(void)
1730 {
1731 #ifdef CONFIG_SMP
1732 return (current->flags & PF_NO_SETAFFINITY) &&
1733 (current->nr_cpus_allowed == 1);
1734 #else
1735 return true;
1736 #endif
1737 }
1738
1739 /* Per-process atomic flags. */
1740 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */
1741 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */
1742 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */
1743 #define PFA_SPEC_SSB_DISABLE 3 /* Speculative Store Bypass disabled */
1744 #define PFA_SPEC_SSB_FORCE_DISABLE 4 /* Speculative Store Bypass force disabled*/
1745 #define PFA_SPEC_IB_DISABLE 5 /* Indirect branch speculation restricted */
1746 #define PFA_SPEC_IB_FORCE_DISABLE 6 /* Indirect branch speculation permanently restricted */
1747 #define PFA_SPEC_SSB_NOEXEC 7 /* Speculative Store Bypass clear on execve() */
1748
1749 #define TASK_PFA_TEST(name, func) \
1750 static inline bool task_##func(struct task_struct *p) \
1751 { return test_bit(PFA_##name, &p->atomic_flags); }
1752
1753 #define TASK_PFA_SET(name, func) \
1754 static inline void task_set_##func(struct task_struct *p) \
1755 { set_bit(PFA_##name, &p->atomic_flags); }
1756
1757 #define TASK_PFA_CLEAR(name, func) \
1758 static inline void task_clear_##func(struct task_struct *p) \
1759 { clear_bit(PFA_##name, &p->atomic_flags); }
1760
TASK_PFA_TEST(NO_NEW_PRIVS,no_new_privs)1761 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
1762 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
1763
1764 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
1765 TASK_PFA_SET(SPREAD_PAGE, spread_page)
1766 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
1767
1768 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
1769 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
1770 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
1771
1772 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable)
1773 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable)
1774 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable)
1775
1776 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1777 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1778 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1779
1780 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1781 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1782
1783 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable)
1784 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable)
1785 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable)
1786
1787 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1788 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1789
1790 static inline void
1791 current_restore_flags(unsigned long orig_flags, unsigned long flags)
1792 {
1793 current->flags &= ~flags;
1794 current->flags |= orig_flags & flags;
1795 }
1796
1797 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
1798 extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed);
1799 #ifdef CONFIG_SMP
1800 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
1801 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
1802 #else
do_set_cpus_allowed(struct task_struct * p,const struct cpumask * new_mask)1803 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
1804 {
1805 }
set_cpus_allowed_ptr(struct task_struct * p,const struct cpumask * new_mask)1806 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
1807 {
1808 if (!cpumask_test_cpu(0, new_mask))
1809 return -EINVAL;
1810 return 0;
1811 }
1812 #endif
1813
1814 extern int yield_to(struct task_struct *p, bool preempt);
1815 extern void set_user_nice(struct task_struct *p, long nice);
1816 extern int task_prio(const struct task_struct *p);
1817
1818 /**
1819 * task_nice - return the nice value of a given task.
1820 * @p: the task in question.
1821 *
1822 * Return: The nice value [ -20 ... 0 ... 19 ].
1823 */
task_nice(const struct task_struct * p)1824 static inline int task_nice(const struct task_struct *p)
1825 {
1826 return PRIO_TO_NICE((p)->static_prio);
1827 }
1828
1829 extern int can_nice(const struct task_struct *p, const int nice);
1830 extern int task_curr(const struct task_struct *p);
1831 extern int idle_cpu(int cpu);
1832 extern int available_idle_cpu(int cpu);
1833 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *);
1834 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *);
1835 extern void sched_set_fifo(struct task_struct *p);
1836 extern void sched_set_fifo_low(struct task_struct *p);
1837 extern void sched_set_normal(struct task_struct *p, int nice);
1838 extern int sched_setattr(struct task_struct *, const struct sched_attr *);
1839 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *);
1840 extern struct task_struct *idle_task(int cpu);
1841
1842 /**
1843 * is_idle_task - is the specified task an idle task?
1844 * @p: the task in question.
1845 *
1846 * Return: 1 if @p is an idle task. 0 otherwise.
1847 */
is_idle_task(const struct task_struct * p)1848 static __always_inline bool is_idle_task(const struct task_struct *p)
1849 {
1850 return !!(p->flags & PF_IDLE);
1851 }
1852
1853 extern struct task_struct *curr_task(int cpu);
1854 extern void ia64_set_curr_task(int cpu, struct task_struct *p);
1855
1856 void yield(void);
1857
1858 union thread_union {
1859 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK
1860 struct task_struct task;
1861 #endif
1862 #ifndef CONFIG_THREAD_INFO_IN_TASK
1863 struct thread_info thread_info;
1864 #endif
1865 unsigned long stack[THREAD_SIZE/sizeof(long)];
1866 };
1867
1868 #ifndef CONFIG_THREAD_INFO_IN_TASK
1869 extern struct thread_info init_thread_info;
1870 #endif
1871
1872 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
1873
1874 #ifdef CONFIG_THREAD_INFO_IN_TASK
task_thread_info(struct task_struct * task)1875 static inline struct thread_info *task_thread_info(struct task_struct *task)
1876 {
1877 return &task->thread_info;
1878 }
1879 #elif !defined(__HAVE_THREAD_FUNCTIONS)
1880 # define task_thread_info(task) ((struct thread_info *)(task)->stack)
1881 #endif
1882
1883 /*
1884 * find a task by one of its numerical ids
1885 *
1886 * find_task_by_pid_ns():
1887 * finds a task by its pid in the specified namespace
1888 * find_task_by_vpid():
1889 * finds a task by its virtual pid
1890 *
1891 * see also find_vpid() etc in include/linux/pid.h
1892 */
1893
1894 extern struct task_struct *find_task_by_vpid(pid_t nr);
1895 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns);
1896
1897 /*
1898 * find a task by its virtual pid and get the task struct
1899 */
1900 extern struct task_struct *find_get_task_by_vpid(pid_t nr);
1901
1902 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
1903 extern int wake_up_process(struct task_struct *tsk);
1904 extern void wake_up_new_task(struct task_struct *tsk);
1905
1906 #ifdef CONFIG_SMP
1907 extern void kick_process(struct task_struct *tsk);
1908 #else
kick_process(struct task_struct * tsk)1909 static inline void kick_process(struct task_struct *tsk) { }
1910 #endif
1911
1912 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
1913
set_task_comm(struct task_struct * tsk,const char * from)1914 static inline void set_task_comm(struct task_struct *tsk, const char *from)
1915 {
1916 __set_task_comm(tsk, from, false);
1917 }
1918
1919 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk);
1920 #define get_task_comm(buf, tsk) ({ \
1921 BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN); \
1922 __get_task_comm(buf, sizeof(buf), tsk); \
1923 })
1924
1925 #ifdef CONFIG_SMP
scheduler_ipi(void)1926 static __always_inline void scheduler_ipi(void)
1927 {
1928 /*
1929 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting
1930 * TIF_NEED_RESCHED remotely (for the first time) will also send
1931 * this IPI.
1932 */
1933 preempt_fold_need_resched();
1934 }
1935 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
1936 #else
scheduler_ipi(void)1937 static inline void scheduler_ipi(void) { }
wait_task_inactive(struct task_struct * p,long match_state)1938 static inline unsigned long wait_task_inactive(struct task_struct *p, long match_state)
1939 {
1940 return 1;
1941 }
1942 #endif
1943
1944 /*
1945 * Set thread flags in other task's structures.
1946 * See asm/thread_info.h for TIF_xxxx flags available:
1947 */
set_tsk_thread_flag(struct task_struct * tsk,int flag)1948 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
1949 {
1950 set_ti_thread_flag(task_thread_info(tsk), flag);
1951 }
1952
clear_tsk_thread_flag(struct task_struct * tsk,int flag)1953 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1954 {
1955 clear_ti_thread_flag(task_thread_info(tsk), flag);
1956 }
1957
update_tsk_thread_flag(struct task_struct * tsk,int flag,bool value)1958 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag,
1959 bool value)
1960 {
1961 update_ti_thread_flag(task_thread_info(tsk), flag, value);
1962 }
1963
test_and_set_tsk_thread_flag(struct task_struct * tsk,int flag)1964 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
1965 {
1966 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
1967 }
1968
test_and_clear_tsk_thread_flag(struct task_struct * tsk,int flag)1969 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1970 {
1971 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
1972 }
1973
test_tsk_thread_flag(struct task_struct * tsk,int flag)1974 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
1975 {
1976 return test_ti_thread_flag(task_thread_info(tsk), flag);
1977 }
1978
set_tsk_need_resched(struct task_struct * tsk)1979 static inline void set_tsk_need_resched(struct task_struct *tsk)
1980 {
1981 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1982 }
1983
clear_tsk_need_resched(struct task_struct * tsk)1984 static inline void clear_tsk_need_resched(struct task_struct *tsk)
1985 {
1986 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1987 }
1988
test_tsk_need_resched(struct task_struct * tsk)1989 static inline int test_tsk_need_resched(struct task_struct *tsk)
1990 {
1991 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
1992 }
1993
1994 /*
1995 * cond_resched() and cond_resched_lock(): latency reduction via
1996 * explicit rescheduling in places that are safe. The return
1997 * value indicates whether a reschedule was done in fact.
1998 * cond_resched_lock() will drop the spinlock before scheduling,
1999 */
2000 #ifndef CONFIG_PREEMPTION
2001 extern int _cond_resched(void);
2002 #else
_cond_resched(void)2003 static inline int _cond_resched(void) { return 0; }
2004 #endif
2005
2006 #define cond_resched() ({ \
2007 ___might_sleep(__FILE__, __LINE__, 0); \
2008 _cond_resched(); \
2009 })
2010
2011 extern int __cond_resched_lock(spinlock_t *lock);
2012
2013 #define cond_resched_lock(lock) ({ \
2014 ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
2015 __cond_resched_lock(lock); \
2016 })
2017
cond_resched_rcu(void)2018 static inline void cond_resched_rcu(void)
2019 {
2020 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
2021 rcu_read_unlock();
2022 cond_resched();
2023 rcu_read_lock();
2024 #endif
2025 }
2026
2027 /*
2028 * Does a critical section need to be broken due to another
2029 * task waiting?: (technically does not depend on CONFIG_PREEMPTION,
2030 * but a general need for low latency)
2031 */
spin_needbreak(spinlock_t * lock)2032 static inline int spin_needbreak(spinlock_t *lock)
2033 {
2034 #ifdef CONFIG_PREEMPTION
2035 return spin_is_contended(lock);
2036 #else
2037 return 0;
2038 #endif
2039 }
2040
need_resched(void)2041 static __always_inline bool need_resched(void)
2042 {
2043 return unlikely(tif_need_resched());
2044 }
2045
2046 /*
2047 * Wrappers for p->thread_info->cpu access. No-op on UP.
2048 */
2049 #ifdef CONFIG_SMP
2050
task_cpu(const struct task_struct * p)2051 static inline unsigned int task_cpu(const struct task_struct *p)
2052 {
2053 #ifdef CONFIG_THREAD_INFO_IN_TASK
2054 return READ_ONCE(p->cpu);
2055 #else
2056 return READ_ONCE(task_thread_info(p)->cpu);
2057 #endif
2058 }
2059
2060 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2061
2062 #else
2063
task_cpu(const struct task_struct * p)2064 static inline unsigned int task_cpu(const struct task_struct *p)
2065 {
2066 return 0;
2067 }
2068
set_task_cpu(struct task_struct * p,unsigned int cpu)2069 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2070 {
2071 }
2072
2073 #endif /* CONFIG_SMP */
2074
2075 /*
2076 * In order to reduce various lock holder preemption latencies provide an
2077 * interface to see if a vCPU is currently running or not.
2078 *
2079 * This allows us to terminate optimistic spin loops and block, analogous to
2080 * the native optimistic spin heuristic of testing if the lock owner task is
2081 * running or not.
2082 */
2083 #ifndef vcpu_is_preempted
vcpu_is_preempted(int cpu)2084 static inline bool vcpu_is_preempted(int cpu)
2085 {
2086 return false;
2087 }
2088 #endif
2089
2090 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2091 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2092
2093 #ifndef TASK_SIZE_OF
2094 #define TASK_SIZE_OF(tsk) TASK_SIZE
2095 #endif
2096
2097 #ifdef CONFIG_RSEQ
2098
2099 /*
2100 * Map the event mask on the user-space ABI enum rseq_cs_flags
2101 * for direct mask checks.
2102 */
2103 enum rseq_event_mask_bits {
2104 RSEQ_EVENT_PREEMPT_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT,
2105 RSEQ_EVENT_SIGNAL_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT,
2106 RSEQ_EVENT_MIGRATE_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT,
2107 };
2108
2109 enum rseq_event_mask {
2110 RSEQ_EVENT_PREEMPT = (1U << RSEQ_EVENT_PREEMPT_BIT),
2111 RSEQ_EVENT_SIGNAL = (1U << RSEQ_EVENT_SIGNAL_BIT),
2112 RSEQ_EVENT_MIGRATE = (1U << RSEQ_EVENT_MIGRATE_BIT),
2113 };
2114
rseq_set_notify_resume(struct task_struct * t)2115 static inline void rseq_set_notify_resume(struct task_struct *t)
2116 {
2117 if (t->rseq)
2118 set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
2119 }
2120
2121 void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs);
2122
rseq_handle_notify_resume(struct ksignal * ksig,struct pt_regs * regs)2123 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
2124 struct pt_regs *regs)
2125 {
2126 if (current->rseq)
2127 __rseq_handle_notify_resume(ksig, regs);
2128 }
2129
rseq_signal_deliver(struct ksignal * ksig,struct pt_regs * regs)2130 static inline void rseq_signal_deliver(struct ksignal *ksig,
2131 struct pt_regs *regs)
2132 {
2133 preempt_disable();
2134 __set_bit(RSEQ_EVENT_SIGNAL_BIT, ¤t->rseq_event_mask);
2135 preempt_enable();
2136 rseq_handle_notify_resume(ksig, regs);
2137 }
2138
2139 /* rseq_preempt() requires preemption to be disabled. */
rseq_preempt(struct task_struct * t)2140 static inline void rseq_preempt(struct task_struct *t)
2141 {
2142 __set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask);
2143 rseq_set_notify_resume(t);
2144 }
2145
2146 /* rseq_migrate() requires preemption to be disabled. */
rseq_migrate(struct task_struct * t)2147 static inline void rseq_migrate(struct task_struct *t)
2148 {
2149 __set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask);
2150 rseq_set_notify_resume(t);
2151 }
2152
2153 /*
2154 * If parent process has a registered restartable sequences area, the
2155 * child inherits. Unregister rseq for a clone with CLONE_VM set.
2156 */
rseq_fork(struct task_struct * t,unsigned long clone_flags)2157 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
2158 {
2159 if (clone_flags & CLONE_VM) {
2160 t->rseq = NULL;
2161 t->rseq_sig = 0;
2162 t->rseq_event_mask = 0;
2163 } else {
2164 t->rseq = current->rseq;
2165 t->rseq_sig = current->rseq_sig;
2166 t->rseq_event_mask = current->rseq_event_mask;
2167 }
2168 }
2169
rseq_execve(struct task_struct * t)2170 static inline void rseq_execve(struct task_struct *t)
2171 {
2172 t->rseq = NULL;
2173 t->rseq_sig = 0;
2174 t->rseq_event_mask = 0;
2175 }
2176
2177 #else
2178
rseq_set_notify_resume(struct task_struct * t)2179 static inline void rseq_set_notify_resume(struct task_struct *t)
2180 {
2181 }
rseq_handle_notify_resume(struct ksignal * ksig,struct pt_regs * regs)2182 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
2183 struct pt_regs *regs)
2184 {
2185 }
rseq_signal_deliver(struct ksignal * ksig,struct pt_regs * regs)2186 static inline void rseq_signal_deliver(struct ksignal *ksig,
2187 struct pt_regs *regs)
2188 {
2189 }
rseq_preempt(struct task_struct * t)2190 static inline void rseq_preempt(struct task_struct *t)
2191 {
2192 }
rseq_migrate(struct task_struct * t)2193 static inline void rseq_migrate(struct task_struct *t)
2194 {
2195 }
rseq_fork(struct task_struct * t,unsigned long clone_flags)2196 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
2197 {
2198 }
rseq_execve(struct task_struct * t)2199 static inline void rseq_execve(struct task_struct *t)
2200 {
2201 }
2202
2203 #endif
2204
2205 #ifdef CONFIG_DEBUG_RSEQ
2206
2207 void rseq_syscall(struct pt_regs *regs);
2208
2209 #else
2210
rseq_syscall(struct pt_regs * regs)2211 static inline void rseq_syscall(struct pt_regs *regs)
2212 {
2213 }
2214
2215 #endif
2216
2217 const struct sched_avg *sched_trace_cfs_rq_avg(struct cfs_rq *cfs_rq);
2218 char *sched_trace_cfs_rq_path(struct cfs_rq *cfs_rq, char *str, int len);
2219 int sched_trace_cfs_rq_cpu(struct cfs_rq *cfs_rq);
2220
2221 const struct sched_avg *sched_trace_rq_avg_rt(struct rq *rq);
2222 const struct sched_avg *sched_trace_rq_avg_dl(struct rq *rq);
2223 const struct sched_avg *sched_trace_rq_avg_irq(struct rq *rq);
2224
2225 int sched_trace_rq_cpu(struct rq *rq);
2226 int sched_trace_rq_cpu_capacity(struct rq *rq);
2227 int sched_trace_rq_nr_running(struct rq *rq);
2228
2229 const struct cpumask *sched_trace_rd_span(struct root_domain *rd);
2230
2231 #endif
2232