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TOMOYO Linux Cross Reference
Linux/include/linux/sched.h

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  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/seccomp.h>
 22 #include <linux/nodemask.h>
 23 #include <linux/rcupdate.h>
 24 #include <linux/resource.h>
 25 #include <linux/latencytop.h>
 26 #include <linux/sched/prio.h>
 27 #include <linux/signal_types.h>
 28 #include <linux/psi_types.h>
 29 #include <linux/mm_types_task.h>
 30 #include <linux/task_io_accounting.h>
 31 #include <linux/rseq.h>
 32 
 33 /* task_struct member predeclarations (sorted alphabetically): */
 34 struct audit_context;
 35 struct backing_dev_info;
 36 struct bio_list;
 37 struct blk_plug;
 38 struct ccs_domain_info;
 39 struct cfs_rq;
 40 struct fs_struct;
 41 struct futex_pi_state;
 42 struct io_context;
 43 struct mempolicy;
 44 struct nameidata;
 45 struct nsproxy;
 46 struct perf_event_context;
 47 struct pid_namespace;
 48 struct pipe_inode_info;
 49 struct rcu_node;
 50 struct reclaim_state;
 51 struct robust_list_head;
 52 struct sched_attr;
 53 struct sched_param;
 54 struct seq_file;
 55 struct sighand_struct;
 56 struct signal_struct;
 57 struct task_delay_info;
 58 struct task_group;
 59 
 60 /*
 61  * Task state bitmask. NOTE! These bits are also
 62  * encoded in fs/proc/array.c: get_task_state().
 63  *
 64  * We have two separate sets of flags: task->state
 65  * is about runnability, while task->exit_state are
 66  * about the task exiting. Confusing, but this way
 67  * modifying one set can't modify the other one by
 68  * mistake.
 69  */
 70 
 71 /* Used in tsk->state: */
 72 #define TASK_RUNNING                    0x0000
 73 #define TASK_INTERRUPTIBLE              0x0001
 74 #define TASK_UNINTERRUPTIBLE            0x0002
 75 #define __TASK_STOPPED                  0x0004
 76 #define __TASK_TRACED                   0x0008
 77 /* Used in tsk->exit_state: */
 78 #define EXIT_DEAD                       0x0010
 79 #define EXIT_ZOMBIE                     0x0020
 80 #define EXIT_TRACE                      (EXIT_ZOMBIE | EXIT_DEAD)
 81 /* Used in tsk->state again: */
 82 #define TASK_PARKED                     0x0040
 83 #define TASK_DEAD                       0x0080
 84 #define TASK_WAKEKILL                   0x0100
 85 #define TASK_WAKING                     0x0200
 86 #define TASK_NOLOAD                     0x0400
 87 #define TASK_NEW                        0x0800
 88 #define TASK_STATE_MAX                  0x1000
 89 
 90 /* Convenience macros for the sake of set_current_state: */
 91 #define TASK_KILLABLE                   (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
 92 #define TASK_STOPPED                    (TASK_WAKEKILL | __TASK_STOPPED)
 93 #define TASK_TRACED                     (TASK_WAKEKILL | __TASK_TRACED)
 94 
 95 #define TASK_IDLE                       (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
 96 
 97 /* Convenience macros for the sake of wake_up(): */
 98 #define TASK_NORMAL                     (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
 99 
100 /* get_task_state(): */
101 #define TASK_REPORT                     (TASK_RUNNING | TASK_INTERRUPTIBLE | \
102                                          TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
103                                          __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
104                                          TASK_PARKED)
105 
106 #define task_is_traced(task)            ((task->state & __TASK_TRACED) != 0)
107 
108 #define task_is_stopped(task)           ((task->state & __TASK_STOPPED) != 0)
109 
110 #define task_is_stopped_or_traced(task) ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
111 
112 #define task_contributes_to_load(task)  ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
113                                          (task->flags & PF_FROZEN) == 0 && \
114                                          (task->state & TASK_NOLOAD) == 0)
115 
116 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
117 
118 /*
119  * Special states are those that do not use the normal wait-loop pattern. See
120  * the comment with set_special_state().
121  */
122 #define is_special_task_state(state)                            \
123         ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD))
124 
125 #define __set_current_state(state_value)                        \
126         do {                                                    \
127                 WARN_ON_ONCE(is_special_task_state(state_value));\
128                 current->task_state_change = _THIS_IP_;         \
129                 current->state = (state_value);                 \
130         } while (0)
131 
132 #define set_current_state(state_value)                          \
133         do {                                                    \
134                 WARN_ON_ONCE(is_special_task_state(state_value));\
135                 current->task_state_change = _THIS_IP_;         \
136                 smp_store_mb(current->state, (state_value));    \
137         } while (0)
138 
139 #define set_special_state(state_value)                                  \
140         do {                                                            \
141                 unsigned long flags; /* may shadow */                   \
142                 WARN_ON_ONCE(!is_special_task_state(state_value));      \
143                 raw_spin_lock_irqsave(&current->pi_lock, flags);        \
144                 current->task_state_change = _THIS_IP_;                 \
145                 current->state = (state_value);                         \
146                 raw_spin_unlock_irqrestore(&current->pi_lock, flags);   \
147         } while (0)
148 #else
149 /*
150  * set_current_state() includes a barrier so that the write of current->state
151  * is correctly serialised wrt the caller's subsequent test of whether to
152  * actually sleep:
153  *
154  *   for (;;) {
155  *      set_current_state(TASK_UNINTERRUPTIBLE);
156  *      if (!need_sleep)
157  *              break;
158  *
159  *      schedule();
160  *   }
161  *   __set_current_state(TASK_RUNNING);
162  *
163  * If the caller does not need such serialisation (because, for instance, the
164  * condition test and condition change and wakeup are under the same lock) then
165  * use __set_current_state().
166  *
167  * The above is typically ordered against the wakeup, which does:
168  *
169  *   need_sleep = false;
170  *   wake_up_state(p, TASK_UNINTERRUPTIBLE);
171  *
172  * where wake_up_state() executes a full memory barrier before accessing the
173  * task state.
174  *
175  * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is,
176  * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
177  * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
178  *
179  * However, with slightly different timing the wakeup TASK_RUNNING store can
180  * also collide with the TASK_UNINTERRUPTIBLE store. Loosing that store is not
181  * a problem either because that will result in one extra go around the loop
182  * and our @cond test will save the day.
183  *
184  * Also see the comments of try_to_wake_up().
185  */
186 #define __set_current_state(state_value)                                \
187         current->state = (state_value)
188 
189 #define set_current_state(state_value)                                  \
190         smp_store_mb(current->state, (state_value))
191 
192 /*
193  * set_special_state() should be used for those states when the blocking task
194  * can not use the regular condition based wait-loop. In that case we must
195  * serialize against wakeups such that any possible in-flight TASK_RUNNING stores
196  * will not collide with our state change.
197  */
198 #define set_special_state(state_value)                                  \
199         do {                                                            \
200                 unsigned long flags; /* may shadow */                   \
201                 raw_spin_lock_irqsave(&current->pi_lock, flags);        \
202                 current->state = (state_value);                         \
203                 raw_spin_unlock_irqrestore(&current->pi_lock, flags);   \
204         } while (0)
205 
206 #endif
207 
208 /* Task command name length: */
209 #define TASK_COMM_LEN                   16
210 
211 extern void scheduler_tick(void);
212 
213 #define MAX_SCHEDULE_TIMEOUT            LONG_MAX
214 
215 extern long schedule_timeout(long timeout);
216 extern long schedule_timeout_interruptible(long timeout);
217 extern long schedule_timeout_killable(long timeout);
218 extern long schedule_timeout_uninterruptible(long timeout);
219 extern long schedule_timeout_idle(long timeout);
220 asmlinkage void schedule(void);
221 extern void schedule_preempt_disabled(void);
222 
223 extern int __must_check io_schedule_prepare(void);
224 extern void io_schedule_finish(int token);
225 extern long io_schedule_timeout(long timeout);
226 extern void io_schedule(void);
227 
228 /**
229  * struct prev_cputime - snapshot of system and user cputime
230  * @utime: time spent in user mode
231  * @stime: time spent in system mode
232  * @lock: protects the above two fields
233  *
234  * Stores previous user/system time values such that we can guarantee
235  * monotonicity.
236  */
237 struct prev_cputime {
238 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
239         u64                             utime;
240         u64                             stime;
241         raw_spinlock_t                  lock;
242 #endif
243 };
244 
245 /**
246  * struct task_cputime - collected CPU time counts
247  * @utime:              time spent in user mode, in nanoseconds
248  * @stime:              time spent in kernel mode, in nanoseconds
249  * @sum_exec_runtime:   total time spent on the CPU, in nanoseconds
250  *
251  * This structure groups together three kinds of CPU time that are tracked for
252  * threads and thread groups.  Most things considering CPU time want to group
253  * these counts together and treat all three of them in parallel.
254  */
255 struct task_cputime {
256         u64                             utime;
257         u64                             stime;
258         unsigned long long              sum_exec_runtime;
259 };
260 
261 /* Alternate field names when used on cache expirations: */
262 #define virt_exp                        utime
263 #define prof_exp                        stime
264 #define sched_exp                       sum_exec_runtime
265 
266 enum vtime_state {
267         /* Task is sleeping or running in a CPU with VTIME inactive: */
268         VTIME_INACTIVE = 0,
269         /* Task runs in userspace in a CPU with VTIME active: */
270         VTIME_USER,
271         /* Task runs in kernelspace in a CPU with VTIME active: */
272         VTIME_SYS,
273 };
274 
275 struct vtime {
276         seqcount_t              seqcount;
277         unsigned long long      starttime;
278         enum vtime_state        state;
279         u64                     utime;
280         u64                     stime;
281         u64                     gtime;
282 };
283 
284 struct sched_info {
285 #ifdef CONFIG_SCHED_INFO
286         /* Cumulative counters: */
287 
288         /* # of times we have run on this CPU: */
289         unsigned long                   pcount;
290 
291         /* Time spent waiting on a runqueue: */
292         unsigned long long              run_delay;
293 
294         /* Timestamps: */
295 
296         /* When did we last run on a CPU? */
297         unsigned long long              last_arrival;
298 
299         /* When were we last queued to run? */
300         unsigned long long              last_queued;
301 
302 #endif /* CONFIG_SCHED_INFO */
303 };
304 
305 /*
306  * Integer metrics need fixed point arithmetic, e.g., sched/fair
307  * has a few: load, load_avg, util_avg, freq, and capacity.
308  *
309  * We define a basic fixed point arithmetic range, and then formalize
310  * all these metrics based on that basic range.
311  */
312 # define SCHED_FIXEDPOINT_SHIFT         10
313 # define SCHED_FIXEDPOINT_SCALE         (1L << SCHED_FIXEDPOINT_SHIFT)
314 
315 struct load_weight {
316         unsigned long                   weight;
317         u32                             inv_weight;
318 };
319 
320 /**
321  * struct util_est - Estimation utilization of FAIR tasks
322  * @enqueued: instantaneous estimated utilization of a task/cpu
323  * @ewma:     the Exponential Weighted Moving Average (EWMA)
324  *            utilization of a task
325  *
326  * Support data structure to track an Exponential Weighted Moving Average
327  * (EWMA) of a FAIR task's utilization. New samples are added to the moving
328  * average each time a task completes an activation. Sample's weight is chosen
329  * so that the EWMA will be relatively insensitive to transient changes to the
330  * task's workload.
331  *
332  * The enqueued attribute has a slightly different meaning for tasks and cpus:
333  * - task:   the task's util_avg at last task dequeue time
334  * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU
335  * Thus, the util_est.enqueued of a task represents the contribution on the
336  * estimated utilization of the CPU where that task is currently enqueued.
337  *
338  * Only for tasks we track a moving average of the past instantaneous
339  * estimated utilization. This allows to absorb sporadic drops in utilization
340  * of an otherwise almost periodic task.
341  */
342 struct util_est {
343         unsigned int                    enqueued;
344         unsigned int                    ewma;
345 #define UTIL_EST_WEIGHT_SHIFT           2
346 } __attribute__((__aligned__(sizeof(u64))));
347 
348 /*
349  * The load_avg/util_avg accumulates an infinite geometric series
350  * (see __update_load_avg() in kernel/sched/fair.c).
351  *
352  * [load_avg definition]
353  *
354  *   load_avg = runnable% * scale_load_down(load)
355  *
356  * where runnable% is the time ratio that a sched_entity is runnable.
357  * For cfs_rq, it is the aggregated load_avg of all runnable and
358  * blocked sched_entities.
359  *
360  * load_avg may also take frequency scaling into account:
361  *
362  *   load_avg = runnable% * scale_load_down(load) * freq%
363  *
364  * where freq% is the CPU frequency normalized to the highest frequency.
365  *
366  * [util_avg definition]
367  *
368  *   util_avg = running% * SCHED_CAPACITY_SCALE
369  *
370  * where running% is the time ratio that a sched_entity is running on
371  * a CPU. For cfs_rq, it is the aggregated util_avg of all runnable
372  * and blocked sched_entities.
373  *
374  * util_avg may also factor frequency scaling and CPU capacity scaling:
375  *
376  *   util_avg = running% * SCHED_CAPACITY_SCALE * freq% * capacity%
377  *
378  * where freq% is the same as above, and capacity% is the CPU capacity
379  * normalized to the greatest capacity (due to uarch differences, etc).
380  *
381  * N.B., the above ratios (runnable%, running%, freq%, and capacity%)
382  * themselves are in the range of [0, 1]. To do fixed point arithmetics,
383  * we therefore scale them to as large a range as necessary. This is for
384  * example reflected by util_avg's SCHED_CAPACITY_SCALE.
385  *
386  * [Overflow issue]
387  *
388  * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
389  * with the highest load (=88761), always runnable on a single cfs_rq,
390  * and should not overflow as the number already hits PID_MAX_LIMIT.
391  *
392  * For all other cases (including 32-bit kernels), struct load_weight's
393  * weight will overflow first before we do, because:
394  *
395  *    Max(load_avg) <= Max(load.weight)
396  *
397  * Then it is the load_weight's responsibility to consider overflow
398  * issues.
399  */
400 struct sched_avg {
401         u64                             last_update_time;
402         u64                             load_sum;
403         u64                             runnable_load_sum;
404         u32                             util_sum;
405         u32                             period_contrib;
406         unsigned long                   load_avg;
407         unsigned long                   runnable_load_avg;
408         unsigned long                   util_avg;
409         struct util_est                 util_est;
410 } ____cacheline_aligned;
411 
412 struct sched_statistics {
413 #ifdef CONFIG_SCHEDSTATS
414         u64                             wait_start;
415         u64                             wait_max;
416         u64                             wait_count;
417         u64                             wait_sum;
418         u64                             iowait_count;
419         u64                             iowait_sum;
420 
421         u64                             sleep_start;
422         u64                             sleep_max;
423         s64                             sum_sleep_runtime;
424 
425         u64                             block_start;
426         u64                             block_max;
427         u64                             exec_max;
428         u64                             slice_max;
429 
430         u64                             nr_migrations_cold;
431         u64                             nr_failed_migrations_affine;
432         u64                             nr_failed_migrations_running;
433         u64                             nr_failed_migrations_hot;
434         u64                             nr_forced_migrations;
435 
436         u64                             nr_wakeups;
437         u64                             nr_wakeups_sync;
438         u64                             nr_wakeups_migrate;
439         u64                             nr_wakeups_local;
440         u64                             nr_wakeups_remote;
441         u64                             nr_wakeups_affine;
442         u64                             nr_wakeups_affine_attempts;
443         u64                             nr_wakeups_passive;
444         u64                             nr_wakeups_idle;
445 #endif
446 };
447 
448 struct sched_entity {
449         /* For load-balancing: */
450         struct load_weight              load;
451         unsigned long                   runnable_weight;
452         struct rb_node                  run_node;
453         struct list_head                group_node;
454         unsigned int                    on_rq;
455 
456         u64                             exec_start;
457         u64                             sum_exec_runtime;
458         u64                             vruntime;
459         u64                             prev_sum_exec_runtime;
460 
461         u64                             nr_migrations;
462 
463         struct sched_statistics         statistics;
464 
465 #ifdef CONFIG_FAIR_GROUP_SCHED
466         int                             depth;
467         struct sched_entity             *parent;
468         /* rq on which this entity is (to be) queued: */
469         struct cfs_rq                   *cfs_rq;
470         /* rq "owned" by this entity/group: */
471         struct cfs_rq                   *my_q;
472 #endif
473 
474 #ifdef CONFIG_SMP
475         /*
476          * Per entity load average tracking.
477          *
478          * Put into separate cache line so it does not
479          * collide with read-mostly values above.
480          */
481         struct sched_avg                avg;
482 #endif
483 };
484 
485 struct sched_rt_entity {
486         struct list_head                run_list;
487         unsigned long                   timeout;
488         unsigned long                   watchdog_stamp;
489         unsigned int                    time_slice;
490         unsigned short                  on_rq;
491         unsigned short                  on_list;
492 
493         struct sched_rt_entity          *back;
494 #ifdef CONFIG_RT_GROUP_SCHED
495         struct sched_rt_entity          *parent;
496         /* rq on which this entity is (to be) queued: */
497         struct rt_rq                    *rt_rq;
498         /* rq "owned" by this entity/group: */
499         struct rt_rq                    *my_q;
500 #endif
501 } __randomize_layout;
502 
503 struct sched_dl_entity {
504         struct rb_node                  rb_node;
505 
506         /*
507          * Original scheduling parameters. Copied here from sched_attr
508          * during sched_setattr(), they will remain the same until
509          * the next sched_setattr().
510          */
511         u64                             dl_runtime;     /* Maximum runtime for each instance    */
512         u64                             dl_deadline;    /* Relative deadline of each instance   */
513         u64                             dl_period;      /* Separation of two instances (period) */
514         u64                             dl_bw;          /* dl_runtime / dl_period               */
515         u64                             dl_density;     /* dl_runtime / dl_deadline             */
516 
517         /*
518          * Actual scheduling parameters. Initialized with the values above,
519          * they are continously updated during task execution. Note that
520          * the remaining runtime could be < 0 in case we are in overrun.
521          */
522         s64                             runtime;        /* Remaining runtime for this instance  */
523         u64                             deadline;       /* Absolute deadline for this instance  */
524         unsigned int                    flags;          /* Specifying the scheduler behaviour   */
525 
526         /*
527          * Some bool flags:
528          *
529          * @dl_throttled tells if we exhausted the runtime. If so, the
530          * task has to wait for a replenishment to be performed at the
531          * next firing of dl_timer.
532          *
533          * @dl_boosted tells if we are boosted due to DI. If so we are
534          * outside bandwidth enforcement mechanism (but only until we
535          * exit the critical section);
536          *
537          * @dl_yielded tells if task gave up the CPU before consuming
538          * all its available runtime during the last job.
539          *
540          * @dl_non_contending tells if the task is inactive while still
541          * contributing to the active utilization. In other words, it
542          * indicates if the inactive timer has been armed and its handler
543          * has not been executed yet. This flag is useful to avoid race
544          * conditions between the inactive timer handler and the wakeup
545          * code.
546          *
547          * @dl_overrun tells if the task asked to be informed about runtime
548          * overruns.
549          */
550         unsigned int                    dl_throttled      : 1;
551         unsigned int                    dl_boosted        : 1;
552         unsigned int                    dl_yielded        : 1;
553         unsigned int                    dl_non_contending : 1;
554         unsigned int                    dl_overrun        : 1;
555 
556         /*
557          * Bandwidth enforcement timer. Each -deadline task has its
558          * own bandwidth to be enforced, thus we need one timer per task.
559          */
560         struct hrtimer                  dl_timer;
561 
562         /*
563          * Inactive timer, responsible for decreasing the active utilization
564          * at the "0-lag time". When a -deadline task blocks, it contributes
565          * to GRUB's active utilization until the "0-lag time", hence a
566          * timer is needed to decrease the active utilization at the correct
567          * time.
568          */
569         struct hrtimer inactive_timer;
570 };
571 
572 union rcu_special {
573         struct {
574                 u8                      blocked;
575                 u8                      need_qs;
576         } b; /* Bits. */
577         u16 s; /* Set of bits. */
578 };
579 
580 enum perf_event_task_context {
581         perf_invalid_context = -1,
582         perf_hw_context = 0,
583         perf_sw_context,
584         perf_nr_task_contexts,
585 };
586 
587 struct wake_q_node {
588         struct wake_q_node *next;
589 };
590 
591 struct task_struct {
592 #ifdef CONFIG_THREAD_INFO_IN_TASK
593         /*
594          * For reasons of header soup (see current_thread_info()), this
595          * must be the first element of task_struct.
596          */
597         struct thread_info              thread_info;
598 #endif
599         /* -1 unrunnable, 0 runnable, >0 stopped: */
600         volatile long                   state;
601 
602         /*
603          * This begins the randomizable portion of task_struct. Only
604          * scheduling-critical items should be added above here.
605          */
606         randomized_struct_fields_start
607 
608         void                            *stack;
609         atomic_t                        usage;
610         /* Per task flags (PF_*), defined further below: */
611         unsigned int                    flags;
612         unsigned int                    ptrace;
613 
614 #ifdef CONFIG_SMP
615         struct llist_node               wake_entry;
616         int                             on_cpu;
617 #ifdef CONFIG_THREAD_INFO_IN_TASK
618         /* Current CPU: */
619         unsigned int                    cpu;
620 #endif
621         unsigned int                    wakee_flips;
622         unsigned long                   wakee_flip_decay_ts;
623         struct task_struct              *last_wakee;
624 
625         /*
626          * recent_used_cpu is initially set as the last CPU used by a task
627          * that wakes affine another task. Waker/wakee relationships can
628          * push tasks around a CPU where each wakeup moves to the next one.
629          * Tracking a recently used CPU allows a quick search for a recently
630          * used CPU that may be idle.
631          */
632         int                             recent_used_cpu;
633         int                             wake_cpu;
634 #endif
635         int                             on_rq;
636 
637         int                             prio;
638         int                             static_prio;
639         int                             normal_prio;
640         unsigned int                    rt_priority;
641 
642         const struct sched_class        *sched_class;
643         struct sched_entity             se;
644         struct sched_rt_entity          rt;
645 #ifdef CONFIG_CGROUP_SCHED
646         struct task_group               *sched_task_group;
647 #endif
648         struct sched_dl_entity          dl;
649 
650 #ifdef CONFIG_PREEMPT_NOTIFIERS
651         /* List of struct preempt_notifier: */
652         struct hlist_head               preempt_notifiers;
653 #endif
654 
655 #ifdef CONFIG_BLK_DEV_IO_TRACE
656         unsigned int                    btrace_seq;
657 #endif
658 
659         unsigned int                    policy;
660         int                             nr_cpus_allowed;
661         cpumask_t                       cpus_allowed;
662 
663 #ifdef CONFIG_PREEMPT_RCU
664         int                             rcu_read_lock_nesting;
665         union rcu_special               rcu_read_unlock_special;
666         struct list_head                rcu_node_entry;
667         struct rcu_node                 *rcu_blocked_node;
668 #endif /* #ifdef CONFIG_PREEMPT_RCU */
669 
670 #ifdef CONFIG_TASKS_RCU
671         unsigned long                   rcu_tasks_nvcsw;
672         u8                              rcu_tasks_holdout;
673         u8                              rcu_tasks_idx;
674         int                             rcu_tasks_idle_cpu;
675         struct list_head                rcu_tasks_holdout_list;
676 #endif /* #ifdef CONFIG_TASKS_RCU */
677 
678         struct sched_info               sched_info;
679 
680         struct list_head                tasks;
681 #ifdef CONFIG_SMP
682         struct plist_node               pushable_tasks;
683         struct rb_node                  pushable_dl_tasks;
684 #endif
685 
686         struct mm_struct                *mm;
687         struct mm_struct                *active_mm;
688 
689         /* Per-thread vma caching: */
690         struct vmacache                 vmacache;
691 
692 #ifdef SPLIT_RSS_COUNTING
693         struct task_rss_stat            rss_stat;
694 #endif
695         int                             exit_state;
696         int                             exit_code;
697         int                             exit_signal;
698         /* The signal sent when the parent dies: */
699         int                             pdeath_signal;
700         /* JOBCTL_*, siglock protected: */
701         unsigned long                   jobctl;
702 
703         /* Used for emulating ABI behavior of previous Linux versions: */
704         unsigned int                    personality;
705 
706         /* Scheduler bits, serialized by scheduler locks: */
707         unsigned                        sched_reset_on_fork:1;
708         unsigned                        sched_contributes_to_load:1;
709         unsigned                        sched_migrated:1;
710         unsigned                        sched_remote_wakeup:1;
711 #ifdef CONFIG_PSI
712         unsigned                        sched_psi_wake_requeue:1;
713 #endif
714 
715         /* Force alignment to the next boundary: */
716         unsigned                        :0;
717 
718         /* Unserialized, strictly 'current' */
719 
720         /* Bit to tell LSMs we're in execve(): */
721         unsigned                        in_execve:1;
722         unsigned                        in_iowait:1;
723 #ifndef TIF_RESTORE_SIGMASK
724         unsigned                        restore_sigmask:1;
725 #endif
726 #ifdef CONFIG_MEMCG
727         unsigned                        in_user_fault:1;
728 #endif
729 #ifdef CONFIG_COMPAT_BRK
730         unsigned                        brk_randomized:1;
731 #endif
732 #ifdef CONFIG_CGROUPS
733         /* disallow userland-initiated cgroup migration */
734         unsigned                        no_cgroup_migration:1;
735 #endif
736 #ifdef CONFIG_BLK_CGROUP
737         /* to be used once the psi infrastructure lands upstream. */
738         unsigned                        use_memdelay:1;
739 #endif
740 
741         /*
742          * May usercopy functions fault on kernel addresses?
743          * This is not just a single bit because this can potentially nest.
744          */
745         unsigned int                    kernel_uaccess_faults_ok;
746 
747         unsigned long                   atomic_flags; /* Flags requiring atomic access. */
748 
749         struct restart_block            restart_block;
750 
751         pid_t                           pid;
752         pid_t                           tgid;
753 
754 #ifdef CONFIG_STACKPROTECTOR
755         /* Canary value for the -fstack-protector GCC feature: */
756         unsigned long                   stack_canary;
757 #endif
758         /*
759          * Pointers to the (original) parent process, youngest child, younger sibling,
760          * older sibling, respectively.  (p->father can be replaced with
761          * p->real_parent->pid)
762          */
763 
764         /* Real parent process: */
765         struct task_struct __rcu        *real_parent;
766 
767         /* Recipient of SIGCHLD, wait4() reports: */
768         struct task_struct __rcu        *parent;
769 
770         /*
771          * Children/sibling form the list of natural children:
772          */
773         struct list_head                children;
774         struct list_head                sibling;
775         struct task_struct              *group_leader;
776 
777         /*
778          * 'ptraced' is the list of tasks this task is using ptrace() on.
779          *
780          * This includes both natural children and PTRACE_ATTACH targets.
781          * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
782          */
783         struct list_head                ptraced;
784         struct list_head                ptrace_entry;
785 
786         /* PID/PID hash table linkage. */
787         struct pid                      *thread_pid;
788         struct hlist_node               pid_links[PIDTYPE_MAX];
789         struct list_head                thread_group;
790         struct list_head                thread_node;
791 
792         struct completion               *vfork_done;
793 
794         /* CLONE_CHILD_SETTID: */
795         int __user                      *set_child_tid;
796 
797         /* CLONE_CHILD_CLEARTID: */
798         int __user                      *clear_child_tid;
799 
800         u64                             utime;
801         u64                             stime;
802 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
803         u64                             utimescaled;
804         u64                             stimescaled;
805 #endif
806         u64                             gtime;
807         struct prev_cputime             prev_cputime;
808 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
809         struct vtime                    vtime;
810 #endif
811 
812 #ifdef CONFIG_NO_HZ_FULL
813         atomic_t                        tick_dep_mask;
814 #endif
815         /* Context switch counts: */
816         unsigned long                   nvcsw;
817         unsigned long                   nivcsw;
818 
819         /* Monotonic time in nsecs: */
820         u64                             start_time;
821 
822         /* Boot based time in nsecs: */
823         u64                             real_start_time;
824 
825         /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
826         unsigned long                   min_flt;
827         unsigned long                   maj_flt;
828 
829 #ifdef CONFIG_POSIX_TIMERS
830         struct task_cputime             cputime_expires;
831         struct list_head                cpu_timers[3];
832 #endif
833 
834         /* Process credentials: */
835 
836         /* Tracer's credentials at attach: */
837         const struct cred __rcu         *ptracer_cred;
838 
839         /* Objective and real subjective task credentials (COW): */
840         const struct cred __rcu         *real_cred;
841 
842         /* Effective (overridable) subjective task credentials (COW): */
843         const struct cred __rcu         *cred;
844 
845         /*
846          * executable name, excluding path.
847          *
848          * - normally initialized setup_new_exec()
849          * - access it with [gs]et_task_comm()
850          * - lock it with task_lock()
851          */
852         char                            comm[TASK_COMM_LEN];
853 
854         struct nameidata                *nameidata;
855 
856 #ifdef CONFIG_SYSVIPC
857         struct sysv_sem                 sysvsem;
858         struct sysv_shm                 sysvshm;
859 #endif
860 #ifdef CONFIG_DETECT_HUNG_TASK
861         unsigned long                   last_switch_count;
862         unsigned long                   last_switch_time;
863 #endif
864         /* Filesystem information: */
865         struct fs_struct                *fs;
866 
867         /* Open file information: */
868         struct files_struct             *files;
869 
870         /* Namespaces: */
871         struct nsproxy                  *nsproxy;
872 
873         /* Signal handlers: */
874         struct signal_struct            *signal;
875         struct sighand_struct           *sighand;
876         sigset_t                        blocked;
877         sigset_t                        real_blocked;
878         /* Restored if set_restore_sigmask() was used: */
879         sigset_t                        saved_sigmask;
880         struct sigpending               pending;
881         unsigned long                   sas_ss_sp;
882         size_t                          sas_ss_size;
883         unsigned int                    sas_ss_flags;
884 
885         struct callback_head            *task_works;
886 
887         struct audit_context            *audit_context;
888 #ifdef CONFIG_AUDITSYSCALL
889         kuid_t                          loginuid;
890         unsigned int                    sessionid;
891 #endif
892         struct seccomp                  seccomp;
893 
894         /* Thread group tracking: */
895         u32                             parent_exec_id;
896         u32                             self_exec_id;
897 
898         /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
899         spinlock_t                      alloc_lock;
900 
901         /* Protection of the PI data structures: */
902         raw_spinlock_t                  pi_lock;
903 
904         struct wake_q_node              wake_q;
905 
906 #ifdef CONFIG_RT_MUTEXES
907         /* PI waiters blocked on a rt_mutex held by this task: */
908         struct rb_root_cached           pi_waiters;
909         /* Updated under owner's pi_lock and rq lock */
910         struct task_struct              *pi_top_task;
911         /* Deadlock detection and priority inheritance handling: */
912         struct rt_mutex_waiter          *pi_blocked_on;
913 #endif
914 
915 #ifdef CONFIG_DEBUG_MUTEXES
916         /* Mutex deadlock detection: */
917         struct mutex_waiter             *blocked_on;
918 #endif
919 
920 #ifdef CONFIG_TRACE_IRQFLAGS
921         unsigned int                    irq_events;
922         unsigned long                   hardirq_enable_ip;
923         unsigned long                   hardirq_disable_ip;
924         unsigned int                    hardirq_enable_event;
925         unsigned int                    hardirq_disable_event;
926         int                             hardirqs_enabled;
927         int                             hardirq_context;
928         unsigned long                   softirq_disable_ip;
929         unsigned long                   softirq_enable_ip;
930         unsigned int                    softirq_disable_event;
931         unsigned int                    softirq_enable_event;
932         int                             softirqs_enabled;
933         int                             softirq_context;
934 #endif
935 
936 #ifdef CONFIG_LOCKDEP
937 # define MAX_LOCK_DEPTH                 48UL
938         u64                             curr_chain_key;
939         int                             lockdep_depth;
940         unsigned int                    lockdep_recursion;
941         struct held_lock                held_locks[MAX_LOCK_DEPTH];
942 #endif
943 
944 #ifdef CONFIG_UBSAN
945         unsigned int                    in_ubsan;
946 #endif
947 
948         /* Journalling filesystem info: */
949         void                            *journal_info;
950 
951         /* Stacked block device info: */
952         struct bio_list                 *bio_list;
953 
954 #ifdef CONFIG_BLOCK
955         /* Stack plugging: */
956         struct blk_plug                 *plug;
957 #endif
958 
959         /* VM state: */
960         struct reclaim_state            *reclaim_state;
961 
962         struct backing_dev_info         *backing_dev_info;
963 
964         struct io_context               *io_context;
965 
966         /* Ptrace state: */
967         unsigned long                   ptrace_message;
968         kernel_siginfo_t                *last_siginfo;
969 
970         struct task_io_accounting       ioac;
971 #ifdef CONFIG_PSI
972         /* Pressure stall state */
973         unsigned int                    psi_flags;
974 #endif
975 #ifdef CONFIG_TASK_XACCT
976         /* Accumulated RSS usage: */
977         u64                             acct_rss_mem1;
978         /* Accumulated virtual memory usage: */
979         u64                             acct_vm_mem1;
980         /* stime + utime since last update: */
981         u64                             acct_timexpd;
982 #endif
983 #ifdef CONFIG_CPUSETS
984         /* Protected by ->alloc_lock: */
985         nodemask_t                      mems_allowed;
986         /* Seqence number to catch updates: */
987         seqcount_t                      mems_allowed_seq;
988         int                             cpuset_mem_spread_rotor;
989         int                             cpuset_slab_spread_rotor;
990 #endif
991 #ifdef CONFIG_CGROUPS
992         /* Control Group info protected by css_set_lock: */
993         struct css_set __rcu            *cgroups;
994         /* cg_list protected by css_set_lock and tsk->alloc_lock: */
995         struct list_head                cg_list;
996 #endif
997 #ifdef CONFIG_INTEL_RDT
998         u32                             closid;
999         u32                             rmid;
1000 #endif
1001 #ifdef CONFIG_FUTEX
1002         struct robust_list_head __user  *robust_list;
1003 #ifdef CONFIG_COMPAT
1004         struct compat_robust_list_head __user *compat_robust_list;
1005 #endif
1006         struct list_head                pi_state_list;
1007         struct futex_pi_state           *pi_state_cache;
1008 #endif
1009 #ifdef CONFIG_PERF_EVENTS
1010         struct perf_event_context       *perf_event_ctxp[perf_nr_task_contexts];
1011         struct mutex                    perf_event_mutex;
1012         struct list_head                perf_event_list;
1013 #endif
1014 #ifdef CONFIG_DEBUG_PREEMPT
1015         unsigned long                   preempt_disable_ip;
1016 #endif
1017 #ifdef CONFIG_NUMA
1018         /* Protected by alloc_lock: */
1019         struct mempolicy                *mempolicy;
1020         short                           il_prev;
1021         short                           pref_node_fork;
1022 #endif
1023 #ifdef CONFIG_NUMA_BALANCING
1024         int                             numa_scan_seq;
1025         unsigned int                    numa_scan_period;
1026         unsigned int                    numa_scan_period_max;
1027         int                             numa_preferred_nid;
1028         unsigned long                   numa_migrate_retry;
1029         /* Migration stamp: */
1030         u64                             node_stamp;
1031         u64                             last_task_numa_placement;
1032         u64                             last_sum_exec_runtime;
1033         struct callback_head            numa_work;
1034 
1035         struct numa_group               *numa_group;
1036 
1037         /*
1038          * numa_faults is an array split into four regions:
1039          * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1040          * in this precise order.
1041          *
1042          * faults_memory: Exponential decaying average of faults on a per-node
1043          * basis. Scheduling placement decisions are made based on these
1044          * counts. The values remain static for the duration of a PTE scan.
1045          * faults_cpu: Track the nodes the process was running on when a NUMA
1046          * hinting fault was incurred.
1047          * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1048          * during the current scan window. When the scan completes, the counts
1049          * in faults_memory and faults_cpu decay and these values are copied.
1050          */
1051         unsigned long                   *numa_faults;
1052         unsigned long                   total_numa_faults;
1053 
1054         /*
1055          * numa_faults_locality tracks if faults recorded during the last
1056          * scan window were remote/local or failed to migrate. The task scan
1057          * period is adapted based on the locality of the faults with different
1058          * weights depending on whether they were shared or private faults
1059          */
1060         unsigned long                   numa_faults_locality[3];
1061 
1062         unsigned long                   numa_pages_migrated;
1063 #endif /* CONFIG_NUMA_BALANCING */
1064 
1065 #ifdef CONFIG_RSEQ
1066         struct rseq __user *rseq;
1067         u32 rseq_len;
1068         u32 rseq_sig;
1069         /*
1070          * RmW on rseq_event_mask must be performed atomically
1071          * with respect to preemption.
1072          */
1073         unsigned long rseq_event_mask;
1074 #endif
1075 
1076         struct tlbflush_unmap_batch     tlb_ubc;
1077 
1078         struct rcu_head                 rcu;
1079 
1080         /* Cache last used pipe for splice(): */
1081         struct pipe_inode_info          *splice_pipe;
1082 
1083         struct page_frag                task_frag;
1084 
1085 #ifdef CONFIG_TASK_DELAY_ACCT
1086         struct task_delay_info          *delays;
1087 #endif
1088 
1089 #ifdef CONFIG_FAULT_INJECTION
1090         int                             make_it_fail;
1091         unsigned int                    fail_nth;
1092 #endif
1093         /*
1094          * When (nr_dirtied >= nr_dirtied_pause), it's time to call
1095          * balance_dirty_pages() for a dirty throttling pause:
1096          */
1097         int                             nr_dirtied;
1098         int                             nr_dirtied_pause;
1099         /* Start of a write-and-pause period: */
1100         unsigned long                   dirty_paused_when;
1101 
1102 #ifdef CONFIG_LATENCYTOP
1103         int                             latency_record_count;
1104         struct latency_record           latency_record[LT_SAVECOUNT];
1105 #endif
1106         /*
1107          * Time slack values; these are used to round up poll() and
1108          * select() etc timeout values. These are in nanoseconds.
1109          */
1110         u64                             timer_slack_ns;
1111         u64                             default_timer_slack_ns;
1112 
1113 #ifdef CONFIG_KASAN
1114         unsigned int                    kasan_depth;
1115 #endif
1116 
1117 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1118         /* Index of current stored address in ret_stack: */
1119         int                             curr_ret_stack;
1120 
1121         /* Stack of return addresses for return function tracing: */
1122         struct ftrace_ret_stack         *ret_stack;
1123 
1124         /* Timestamp for last schedule: */
1125         unsigned long long              ftrace_timestamp;
1126 
1127         /*
1128          * Number of functions that haven't been traced
1129          * because of depth overrun:
1130          */
1131         atomic_t                        trace_overrun;
1132 
1133         /* Pause tracing: */
1134         atomic_t                        tracing_graph_pause;
1135 #endif
1136 
1137 #ifdef CONFIG_TRACING
1138         /* State flags for use by tracers: */
1139         unsigned long                   trace;
1140 
1141         /* Bitmask and counter of trace recursion: */
1142         unsigned long                   trace_recursion;
1143 #endif /* CONFIG_TRACING */
1144 
1145 #ifdef CONFIG_KCOV
1146         /* Coverage collection mode enabled for this task (0 if disabled): */
1147         unsigned int                    kcov_mode;
1148 
1149         /* Size of the kcov_area: */
1150         unsigned int                    kcov_size;
1151 
1152         /* Buffer for coverage collection: */
1153         void                            *kcov_area;
1154 
1155         /* KCOV descriptor wired with this task or NULL: */
1156         struct kcov                     *kcov;
1157 #endif
1158 
1159 #ifdef CONFIG_MEMCG
1160         struct mem_cgroup               *memcg_in_oom;
1161         gfp_t                           memcg_oom_gfp_mask;
1162         int                             memcg_oom_order;
1163 
1164         /* Number of pages to reclaim on returning to userland: */
1165         unsigned int                    memcg_nr_pages_over_high;
1166 
1167         /* Used by memcontrol for targeted memcg charge: */
1168         struct mem_cgroup               *active_memcg;
1169 #endif
1170 
1171 #ifdef CONFIG_BLK_CGROUP
1172         struct request_queue            *throttle_queue;
1173 #endif
1174 
1175 #ifdef CONFIG_UPROBES
1176         struct uprobe_task              *utask;
1177 #endif
1178 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1179         unsigned int                    sequential_io;
1180         unsigned int                    sequential_io_avg;
1181 #endif
1182 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1183         unsigned long                   task_state_change;
1184 #endif
1185         int                             pagefault_disabled;
1186 #ifdef CONFIG_MMU
1187         struct task_struct              *oom_reaper_list;
1188 #endif
1189 #ifdef CONFIG_VMAP_STACK
1190         struct vm_struct                *stack_vm_area;
1191 #endif
1192 #ifdef CONFIG_THREAD_INFO_IN_TASK
1193         /* A live task holds one reference: */
1194         atomic_t                        stack_refcount;
1195 #endif
1196 #ifdef CONFIG_LIVEPATCH
1197         int patch_state;
1198 #endif
1199 #ifdef CONFIG_SECURITY
1200         /* Used by LSM modules for access restriction: */
1201         void                            *security;
1202 #endif
1203 
1204 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK
1205         unsigned long                   lowest_stack;
1206         unsigned long                   prev_lowest_stack;
1207 #endif
1208 #if defined(CONFIG_CCSECURITY) && !defined(CONFIG_CCSECURITY_USE_EXTERNAL_TASK_SECURITY)
1209         struct ccs_domain_info          *ccs_domain_info;
1210         u32                             ccs_flags;
1211 #endif
1212 
1213         /*
1214          * New fields for task_struct should be added above here, so that
1215          * they are included in the randomized portion of task_struct.
1216          */
1217         randomized_struct_fields_end
1218 
1219         /* CPU-specific state of this task: */
1220         struct thread_struct            thread;
1221 
1222         /*
1223          * WARNING: on x86, 'thread_struct' contains a variable-sized
1224          * structure.  It *MUST* be at the end of 'task_struct'.
1225          *
1226          * Do not put anything below here!
1227          */
1228 };
1229 
1230 static inline struct pid *task_pid(struct task_struct *task)
1231 {
1232         return task->thread_pid;
1233 }
1234 
1235 /*
1236  * the helpers to get the task's different pids as they are seen
1237  * from various namespaces
1238  *
1239  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1240  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1241  *                     current.
1242  * task_xid_nr_ns()  : id seen from the ns specified;
1243  *
1244  * see also pid_nr() etc in include/linux/pid.h
1245  */
1246 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns);
1247 
1248 static inline pid_t task_pid_nr(struct task_struct *tsk)
1249 {
1250         return tsk->pid;
1251 }
1252 
1253 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1254 {
1255         return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1256 }
1257 
1258 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1259 {
1260         return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1261 }
1262 
1263 
1264 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1265 {
1266         return tsk->tgid;
1267 }
1268 
1269 /**
1270  * pid_alive - check that a task structure is not stale
1271  * @p: Task structure to be checked.
1272  *
1273  * Test if a process is not yet dead (at most zombie state)
1274  * If pid_alive fails, then pointers within the task structure
1275  * can be stale and must not be dereferenced.
1276  *
1277  * Return: 1 if the process is alive. 0 otherwise.
1278  */
1279 static inline int pid_alive(const struct task_struct *p)
1280 {
1281         return p->thread_pid != NULL;
1282 }
1283 
1284 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1285 {
1286         return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1287 }
1288 
1289 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1290 {
1291         return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1292 }
1293 
1294 
1295 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1296 {
1297         return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1298 }
1299 
1300 static inline pid_t task_session_vnr(struct task_struct *tsk)
1301 {
1302         return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1303 }
1304 
1305 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1306 {
1307         return __task_pid_nr_ns(tsk, PIDTYPE_TGID, ns);
1308 }
1309 
1310 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1311 {
1312         return __task_pid_nr_ns(tsk, PIDTYPE_TGID, NULL);
1313 }
1314 
1315 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1316 {
1317         pid_t pid = 0;
1318 
1319         rcu_read_lock();
1320         if (pid_alive(tsk))
1321                 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1322         rcu_read_unlock();
1323 
1324         return pid;
1325 }
1326 
1327 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1328 {
1329         return task_ppid_nr_ns(tsk, &init_pid_ns);
1330 }
1331 
1332 /* Obsolete, do not use: */
1333 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1334 {
1335         return task_pgrp_nr_ns(tsk, &init_pid_ns);
1336 }
1337 
1338 #define TASK_REPORT_IDLE        (TASK_REPORT + 1)
1339 #define TASK_REPORT_MAX         (TASK_REPORT_IDLE << 1)
1340 
1341 static inline unsigned int task_state_index(struct task_struct *tsk)
1342 {
1343         unsigned int tsk_state = READ_ONCE(tsk->state);
1344         unsigned int state = (tsk_state | tsk->exit_state) & TASK_REPORT;
1345 
1346         BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX);
1347 
1348         if (tsk_state == TASK_IDLE)
1349                 state = TASK_REPORT_IDLE;
1350 
1351         return fls(state);
1352 }
1353 
1354 static inline char task_index_to_char(unsigned int state)
1355 {
1356         static const char state_char[] = "RSDTtXZPI";
1357 
1358         BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1);
1359 
1360         return state_char[state];
1361 }
1362 
1363 static inline char task_state_to_char(struct task_struct *tsk)
1364 {
1365         return task_index_to_char(task_state_index(tsk));
1366 }
1367 
1368 /**
1369  * is_global_init - check if a task structure is init. Since init
1370  * is free to have sub-threads we need to check tgid.
1371  * @tsk: Task structure to be checked.
1372  *
1373  * Check if a task structure is the first user space task the kernel created.
1374  *
1375  * Return: 1 if the task structure is init. 0 otherwise.
1376  */
1377 static inline int is_global_init(struct task_struct *tsk)
1378 {
1379         return task_tgid_nr(tsk) == 1;
1380 }
1381 
1382 extern struct pid *cad_pid;
1383 
1384 /*
1385  * Per process flags
1386  */
1387 #define PF_IDLE                 0x00000002      /* I am an IDLE thread */
1388 #define PF_EXITING              0x00000004      /* Getting shut down */
1389 #define PF_EXITPIDONE           0x00000008      /* PI exit done on shut down */
1390 #define PF_VCPU                 0x00000010      /* I'm a virtual CPU */
1391 #define PF_WQ_WORKER            0x00000020      /* I'm a workqueue worker */
1392 #define PF_FORKNOEXEC           0x00000040      /* Forked but didn't exec */
1393 #define PF_MCE_PROCESS          0x00000080      /* Process policy on mce errors */
1394 #define PF_SUPERPRIV            0x00000100      /* Used super-user privileges */
1395 #define PF_DUMPCORE             0x00000200      /* Dumped core */
1396 #define PF_SIGNALED             0x00000400      /* Killed by a signal */
1397 #define PF_MEMALLOC             0x00000800      /* Allocating memory */
1398 #define PF_NPROC_EXCEEDED       0x00001000      /* set_user() noticed that RLIMIT_NPROC was exceeded */
1399 #define PF_USED_MATH            0x00002000      /* If unset the fpu must be initialized before use */
1400 #define PF_USED_ASYNC           0x00004000      /* Used async_schedule*(), used by module init */
1401 #define PF_NOFREEZE             0x00008000      /* This thread should not be frozen */
1402 #define PF_FROZEN               0x00010000      /* Frozen for system suspend */
1403 #define PF_KSWAPD               0x00020000      /* I am kswapd */
1404 #define PF_MEMALLOC_NOFS        0x00040000      /* All allocation requests will inherit GFP_NOFS */
1405 #define PF_MEMALLOC_NOIO        0x00080000      /* All allocation requests will inherit GFP_NOIO */
1406 #define PF_LESS_THROTTLE        0x00100000      /* Throttle me less: I clean memory */
1407 #define PF_KTHREAD              0x00200000      /* I am a kernel thread */
1408 #define PF_RANDOMIZE            0x00400000      /* Randomize virtual address space */
1409 #define PF_SWAPWRITE            0x00800000      /* Allowed to write to swap */
1410 #define PF_MEMSTALL             0x01000000      /* Stalled due to lack of memory */
1411 #define PF_NO_SETAFFINITY       0x04000000      /* Userland is not allowed to meddle with cpus_allowed */
1412 #define PF_MCE_EARLY            0x08000000      /* Early kill for mce process policy */
1413 #define PF_MUTEX_TESTER         0x20000000      /* Thread belongs to the rt mutex tester */
1414 #define PF_FREEZER_SKIP         0x40000000      /* Freezer should not count it as freezable */
1415 #define PF_SUSPEND_TASK         0x80000000      /* This thread called freeze_processes() and should not be frozen */
1416 
1417 /*
1418  * Only the _current_ task can read/write to tsk->flags, but other
1419  * tasks can access tsk->flags in readonly mode for example
1420  * with tsk_used_math (like during threaded core dumping).
1421  * There is however an exception to this rule during ptrace
1422  * or during fork: the ptracer task is allowed to write to the
1423  * child->flags of its traced child (same goes for fork, the parent
1424  * can write to the child->flags), because we're guaranteed the
1425  * child is not running and in turn not changing child->flags
1426  * at the same time the parent does it.
1427  */
1428 #define clear_stopped_child_used_math(child)    do { (child)->flags &= ~PF_USED_MATH; } while (0)
1429 #define set_stopped_child_used_math(child)      do { (child)->flags |= PF_USED_MATH; } while (0)
1430 #define clear_used_math()                       clear_stopped_child_used_math(current)
1431 #define set_used_math()                         set_stopped_child_used_math(current)
1432 
1433 #define conditional_stopped_child_used_math(condition, child) \
1434         do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1435 
1436 #define conditional_used_math(condition)        conditional_stopped_child_used_math(condition, current)
1437 
1438 #define copy_to_stopped_child_used_math(child) \
1439         do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1440 
1441 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1442 #define tsk_used_math(p)                        ((p)->flags & PF_USED_MATH)
1443 #define used_math()                             tsk_used_math(current)
1444 
1445 static inline bool is_percpu_thread(void)
1446 {
1447 #ifdef CONFIG_SMP
1448         return (current->flags & PF_NO_SETAFFINITY) &&
1449                 (current->nr_cpus_allowed  == 1);
1450 #else
1451         return true;
1452 #endif
1453 }
1454 
1455 /* Per-process atomic flags. */
1456 #define PFA_NO_NEW_PRIVS                0       /* May not gain new privileges. */
1457 #define PFA_SPREAD_PAGE                 1       /* Spread page cache over cpuset */
1458 #define PFA_SPREAD_SLAB                 2       /* Spread some slab caches over cpuset */
1459 #define PFA_SPEC_SSB_DISABLE            3       /* Speculative Store Bypass disabled */
1460 #define PFA_SPEC_SSB_FORCE_DISABLE      4       /* Speculative Store Bypass force disabled*/
1461 
1462 #define TASK_PFA_TEST(name, func)                                       \
1463         static inline bool task_##func(struct task_struct *p)           \
1464         { return test_bit(PFA_##name, &p->atomic_flags); }
1465 
1466 #define TASK_PFA_SET(name, func)                                        \
1467         static inline void task_set_##func(struct task_struct *p)       \
1468         { set_bit(PFA_##name, &p->atomic_flags); }
1469 
1470 #define TASK_PFA_CLEAR(name, func)                                      \
1471         static inline void task_clear_##func(struct task_struct *p)     \
1472         { clear_bit(PFA_##name, &p->atomic_flags); }
1473 
1474 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
1475 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
1476 
1477 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
1478 TASK_PFA_SET(SPREAD_PAGE, spread_page)
1479 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
1480 
1481 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
1482 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
1483 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
1484 
1485 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable)
1486 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable)
1487 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable)
1488 
1489 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1490 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1491 
1492 static inline void
1493 current_restore_flags(unsigned long orig_flags, unsigned long flags)
1494 {
1495         current->flags &= ~flags;
1496         current->flags |= orig_flags & flags;
1497 }
1498 
1499 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
1500 extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed);
1501 #ifdef CONFIG_SMP
1502 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
1503 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
1504 #else
1505 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
1506 {
1507 }
1508 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
1509 {
1510         if (!cpumask_test_cpu(0, new_mask))
1511                 return -EINVAL;
1512         return 0;
1513 }
1514 #endif
1515 
1516 #ifndef cpu_relax_yield
1517 #define cpu_relax_yield() cpu_relax()
1518 #endif
1519 
1520 extern int yield_to(struct task_struct *p, bool preempt);
1521 extern void set_user_nice(struct task_struct *p, long nice);
1522 extern int task_prio(const struct task_struct *p);
1523 
1524 /**
1525  * task_nice - return the nice value of a given task.
1526  * @p: the task in question.
1527  *
1528  * Return: The nice value [ -20 ... 0 ... 19 ].
1529  */
1530 static inline int task_nice(const struct task_struct *p)
1531 {
1532         return PRIO_TO_NICE((p)->static_prio);
1533 }
1534 
1535 extern int can_nice(const struct task_struct *p, const int nice);
1536 extern int task_curr(const struct task_struct *p);
1537 extern int idle_cpu(int cpu);
1538 extern int available_idle_cpu(int cpu);
1539 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *);
1540 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *);
1541 extern int sched_setattr(struct task_struct *, const struct sched_attr *);
1542 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *);
1543 extern struct task_struct *idle_task(int cpu);
1544 
1545 /**
1546  * is_idle_task - is the specified task an idle task?
1547  * @p: the task in question.
1548  *
1549  * Return: 1 if @p is an idle task. 0 otherwise.
1550  */
1551 static inline bool is_idle_task(const struct task_struct *p)
1552 {
1553         return !!(p->flags & PF_IDLE);
1554 }
1555 
1556 extern struct task_struct *curr_task(int cpu);
1557 extern void ia64_set_curr_task(int cpu, struct task_struct *p);
1558 
1559 void yield(void);
1560 
1561 union thread_union {
1562 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK
1563         struct task_struct task;
1564 #endif
1565 #ifndef CONFIG_THREAD_INFO_IN_TASK
1566         struct thread_info thread_info;
1567 #endif
1568         unsigned long stack[THREAD_SIZE/sizeof(long)];
1569 };
1570 
1571 #ifndef CONFIG_THREAD_INFO_IN_TASK
1572 extern struct thread_info init_thread_info;
1573 #endif
1574 
1575 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
1576 
1577 #ifdef CONFIG_THREAD_INFO_IN_TASK
1578 static inline struct thread_info *task_thread_info(struct task_struct *task)
1579 {
1580         return &task->thread_info;
1581 }
1582 #elif !defined(__HAVE_THREAD_FUNCTIONS)
1583 # define task_thread_info(task) ((struct thread_info *)(task)->stack)
1584 #endif
1585 
1586 /*
1587  * find a task by one of its numerical ids
1588  *
1589  * find_task_by_pid_ns():
1590  *      finds a task by its pid in the specified namespace
1591  * find_task_by_vpid():
1592  *      finds a task by its virtual pid
1593  *
1594  * see also find_vpid() etc in include/linux/pid.h
1595  */
1596 
1597 extern struct task_struct *find_task_by_vpid(pid_t nr);
1598 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns);
1599 
1600 /*
1601  * find a task by its virtual pid and get the task struct
1602  */
1603 extern struct task_struct *find_get_task_by_vpid(pid_t nr);
1604 
1605 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
1606 extern int wake_up_process(struct task_struct *tsk);
1607 extern void wake_up_new_task(struct task_struct *tsk);
1608 
1609 #ifdef CONFIG_SMP
1610 extern void kick_process(struct task_struct *tsk);
1611 #else
1612 static inline void kick_process(struct task_struct *tsk) { }
1613 #endif
1614 
1615 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
1616 
1617 static inline void set_task_comm(struct task_struct *tsk, const char *from)
1618 {
1619         __set_task_comm(tsk, from, false);
1620 }
1621 
1622 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk);
1623 #define get_task_comm(buf, tsk) ({                      \
1624         BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN);     \
1625         __get_task_comm(buf, sizeof(buf), tsk);         \
1626 })
1627 
1628 #ifdef CONFIG_SMP
1629 void scheduler_ipi(void);
1630 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
1631 #else
1632 static inline void scheduler_ipi(void) { }
1633 static inline unsigned long wait_task_inactive(struct task_struct *p, long match_state)
1634 {
1635         return 1;
1636 }
1637 #endif
1638 
1639 /*
1640  * Set thread flags in other task's structures.
1641  * See asm/thread_info.h for TIF_xxxx flags available:
1642  */
1643 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
1644 {
1645         set_ti_thread_flag(task_thread_info(tsk), flag);
1646 }
1647 
1648 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1649 {
1650         clear_ti_thread_flag(task_thread_info(tsk), flag);
1651 }
1652 
1653 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag,
1654                                           bool value)
1655 {
1656         update_ti_thread_flag(task_thread_info(tsk), flag, value);
1657 }
1658 
1659 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
1660 {
1661         return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
1662 }
1663 
1664 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1665 {
1666         return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
1667 }
1668 
1669 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
1670 {
1671         return test_ti_thread_flag(task_thread_info(tsk), flag);
1672 }
1673 
1674 static inline void set_tsk_need_resched(struct task_struct *tsk)
1675 {
1676         set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1677 }
1678 
1679 static inline void clear_tsk_need_resched(struct task_struct *tsk)
1680 {
1681         clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1682 }
1683 
1684 static inline int test_tsk_need_resched(struct task_struct *tsk)
1685 {
1686         return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
1687 }
1688 
1689 /*
1690  * cond_resched() and cond_resched_lock(): latency reduction via
1691  * explicit rescheduling in places that are safe. The return
1692  * value indicates whether a reschedule was done in fact.
1693  * cond_resched_lock() will drop the spinlock before scheduling,
1694  */
1695 #ifndef CONFIG_PREEMPT
1696 extern int _cond_resched(void);
1697 #else
1698 static inline int _cond_resched(void) { return 0; }
1699 #endif
1700 
1701 #define cond_resched() ({                       \
1702         ___might_sleep(__FILE__, __LINE__, 0);  \
1703         _cond_resched();                        \
1704 })
1705 
1706 extern int __cond_resched_lock(spinlock_t *lock);
1707 
1708 #define cond_resched_lock(lock) ({                              \
1709         ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
1710         __cond_resched_lock(lock);                              \
1711 })
1712 
1713 static inline void cond_resched_rcu(void)
1714 {
1715 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
1716         rcu_read_unlock();
1717         cond_resched();
1718         rcu_read_lock();
1719 #endif
1720 }
1721 
1722 /*
1723  * Does a critical section need to be broken due to another
1724  * task waiting?: (technically does not depend on CONFIG_PREEMPT,
1725  * but a general need for low latency)
1726  */
1727 static inline int spin_needbreak(spinlock_t *lock)
1728 {
1729 #ifdef CONFIG_PREEMPT
1730         return spin_is_contended(lock);
1731 #else
1732         return 0;
1733 #endif
1734 }
1735 
1736 static __always_inline bool need_resched(void)
1737 {
1738         return unlikely(tif_need_resched());
1739 }
1740 
1741 /*
1742  * Wrappers for p->thread_info->cpu access. No-op on UP.
1743  */
1744 #ifdef CONFIG_SMP
1745 
1746 static inline unsigned int task_cpu(const struct task_struct *p)
1747 {
1748 #ifdef CONFIG_THREAD_INFO_IN_TASK
1749         return p->cpu;
1750 #else
1751         return task_thread_info(p)->cpu;
1752 #endif
1753 }
1754 
1755 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
1756 
1757 #else
1758 
1759 static inline unsigned int task_cpu(const struct task_struct *p)
1760 {
1761         return 0;
1762 }
1763 
1764 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
1765 {
1766 }
1767 
1768 #endif /* CONFIG_SMP */
1769 
1770 /*
1771  * In order to reduce various lock holder preemption latencies provide an
1772  * interface to see if a vCPU is currently running or not.
1773  *
1774  * This allows us to terminate optimistic spin loops and block, analogous to
1775  * the native optimistic spin heuristic of testing if the lock owner task is
1776  * running or not.
1777  */
1778 #ifndef vcpu_is_preempted
1779 # define vcpu_is_preempted(cpu) false
1780 #endif
1781 
1782 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
1783 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
1784 
1785 #ifndef TASK_SIZE_OF
1786 #define TASK_SIZE_OF(tsk)       TASK_SIZE
1787 #endif
1788 
1789 #ifdef CONFIG_RSEQ
1790 
1791 /*
1792  * Map the event mask on the user-space ABI enum rseq_cs_flags
1793  * for direct mask checks.
1794  */
1795 enum rseq_event_mask_bits {
1796         RSEQ_EVENT_PREEMPT_BIT  = RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT,
1797         RSEQ_EVENT_SIGNAL_BIT   = RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT,
1798         RSEQ_EVENT_MIGRATE_BIT  = RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT,
1799 };
1800 
1801 enum rseq_event_mask {
1802         RSEQ_EVENT_PREEMPT      = (1U << RSEQ_EVENT_PREEMPT_BIT),
1803         RSEQ_EVENT_SIGNAL       = (1U << RSEQ_EVENT_SIGNAL_BIT),
1804         RSEQ_EVENT_MIGRATE      = (1U << RSEQ_EVENT_MIGRATE_BIT),
1805 };
1806 
1807 static inline void rseq_set_notify_resume(struct task_struct *t)
1808 {
1809         if (t->rseq)
1810                 set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
1811 }
1812 
1813 void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs);
1814 
1815 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
1816                                              struct pt_regs *regs)
1817 {
1818         if (current->rseq)
1819                 __rseq_handle_notify_resume(ksig, regs);
1820 }
1821 
1822 static inline void rseq_signal_deliver(struct ksignal *ksig,
1823                                        struct pt_regs *regs)
1824 {
1825         preempt_disable();
1826         __set_bit(RSEQ_EVENT_SIGNAL_BIT, &current->rseq_event_mask);
1827         preempt_enable();
1828         rseq_handle_notify_resume(ksig, regs);
1829 }
1830 
1831 /* rseq_preempt() requires preemption to be disabled. */
1832 static inline void rseq_preempt(struct task_struct *t)
1833 {
1834         __set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask);
1835         rseq_set_notify_resume(t);
1836 }
1837 
1838 /* rseq_migrate() requires preemption to be disabled. */
1839 static inline void rseq_migrate(struct task_struct *t)
1840 {
1841         __set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask);
1842         rseq_set_notify_resume(t);
1843 }
1844 
1845 /*
1846  * If parent process has a registered restartable sequences area, the
1847  * child inherits. Only applies when forking a process, not a thread.
1848  */
1849 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
1850 {
1851         if (clone_flags & CLONE_THREAD) {
1852                 t->rseq = NULL;
1853                 t->rseq_len = 0;
1854                 t->rseq_sig = 0;
1855                 t->rseq_event_mask = 0;
1856         } else {
1857                 t->rseq = current->rseq;
1858                 t->rseq_len = current->rseq_len;
1859                 t->rseq_sig = current->rseq_sig;
1860                 t->rseq_event_mask = current->rseq_event_mask;
1861         }
1862 }
1863 
1864 static inline void rseq_execve(struct task_struct *t)
1865 {
1866         t->rseq = NULL;
1867         t->rseq_len = 0;
1868         t->rseq_sig = 0;
1869         t->rseq_event_mask = 0;
1870 }
1871 
1872 #else
1873 
1874 static inline void rseq_set_notify_resume(struct task_struct *t)
1875 {
1876 }
1877 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
1878                                              struct pt_regs *regs)
1879 {
1880 }
1881 static inline void rseq_signal_deliver(struct ksignal *ksig,
1882                                        struct pt_regs *regs)
1883 {
1884 }
1885 static inline void rseq_preempt(struct task_struct *t)
1886 {
1887 }
1888 static inline void rseq_migrate(struct task_struct *t)
1889 {
1890 }
1891 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
1892 {
1893 }
1894 static inline void rseq_execve(struct task_struct *t)
1895 {
1896 }
1897 
1898 #endif
1899 
1900 #ifdef CONFIG_DEBUG_RSEQ
1901 
1902 void rseq_syscall(struct pt_regs *regs);
1903 
1904 #else
1905 
1906 static inline void rseq_syscall(struct pt_regs *regs)
1907 {
1908 }
1909 
1910 #endif
1911 
1912 #endif
1913 

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