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/mutex.h>
  18#include <linux/plist.h>
  19#include <linux/hrtimer.h>
  20#include <linux/irqflags.h>
  21#include <linux/seccomp.h>
  22#include <linux/nodemask.h>
  23#include <linux/rcupdate.h>
  24#include <linux/refcount.h>
  25#include <linux/resource.h>
  26#include <linux/latencytop.h>
  27#include <linux/sched/prio.h>
  28#include <linux/sched/types.h>
  29#include <linux/signal_types.h>
  30#include <linux/syscall_user_dispatch.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 <asm/kmap_size.h>
  38
  39/* task_struct member predeclarations (sorted alphabetically): */
  40struct audit_context;
  41struct backing_dev_info;
  42struct bio_list;
  43struct blk_plug;
  44struct bpf_local_storage;
  45struct capture_control;
  46struct cfs_rq;
  47struct fs_struct;
  48struct futex_pi_state;
  49struct io_context;
  50struct io_uring_task;
  51struct mempolicy;
  52struct nameidata;
  53struct nsproxy;
  54struct perf_event_context;
  55struct pid_namespace;
  56struct pipe_inode_info;
  57struct rcu_node;
  58struct reclaim_state;
  59struct robust_list_head;
  60struct root_domain;
  61struct rq;
  62struct sched_attr;
  63struct sched_param;
  64struct seq_file;
  65struct sighand_struct;
  66struct signal_struct;
  67struct task_delay_info;
  68struct task_group;
  69
  70/*
  71 * Task state bitmask. NOTE! These bits are also
  72 * encoded in fs/proc/array.c: get_task_state().
  73 *
  74 * We have two separate sets of flags: task->state
  75 * is about runnability, while task->exit_state are
  76 * about the task exiting. Confusing, but this way
  77 * modifying one set can't modify the other one by
  78 * mistake.
  79 */
  80
  81/* Used in tsk->state: */
  82#define TASK_RUNNING                    0x0000
  83#define TASK_INTERRUPTIBLE              0x0001
  84#define TASK_UNINTERRUPTIBLE            0x0002
  85#define __TASK_STOPPED                  0x0004
  86#define __TASK_TRACED                   0x0008
  87/* Used in tsk->exit_state: */
  88#define EXIT_DEAD                       0x0010
  89#define EXIT_ZOMBIE                     0x0020
  90#define EXIT_TRACE                      (EXIT_ZOMBIE | EXIT_DEAD)
  91/* Used in tsk->state again: */
  92#define TASK_PARKED                     0x0040
  93#define TASK_DEAD                       0x0080
  94#define TASK_WAKEKILL                   0x0100
  95#define TASK_WAKING                     0x0200
  96#define TASK_NOLOAD                     0x0400
  97#define TASK_NEW                        0x0800
  98#define TASK_STATE_MAX                  0x1000
  99
 100/* Convenience macros for the sake of set_current_state: */
 101#define TASK_KILLABLE                   (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
 102#define TASK_STOPPED                    (TASK_WAKEKILL | __TASK_STOPPED)
 103#define TASK_TRACED                     (TASK_WAKEKILL | __TASK_TRACED)
 104
 105#define TASK_IDLE                       (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
 106
 107/* Convenience macros for the sake of wake_up(): */
 108#define TASK_NORMAL                     (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
 109
 110/* get_task_state(): */
 111#define TASK_REPORT                     (TASK_RUNNING | TASK_INTERRUPTIBLE | \
 112                                         TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
 113                                         __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
 114                                         TASK_PARKED)
 115
 116#define task_is_traced(task)            ((task->state & __TASK_TRACED) != 0)
 117
 118#define task_is_stopped(task)           ((task->state & __TASK_STOPPED) != 0)
 119
 120#define task_is_stopped_or_traced(task) ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
 121
 122#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
 123
 124/*
 125 * Special states are those that do not use the normal wait-loop pattern. See
 126 * the comment with set_special_state().
 127 */
 128#define is_special_task_state(state)                            \
 129        ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD))
 130
 131#define __set_current_state(state_value)                        \
 132        do {                                                    \
 133                WARN_ON_ONCE(is_special_task_state(state_value));\
 134                current->task_state_change = _THIS_IP_;         \
 135                current->state = (state_value);                 \
 136        } while (0)
 137
 138#define set_current_state(state_value)                          \
 139        do {                                                    \
 140                WARN_ON_ONCE(is_special_task_state(state_value));\
 141                current->task_state_change = _THIS_IP_;         \
 142                smp_store_mb(current->state, (state_value));    \
 143        } while (0)
 144
 145#define set_special_state(state_value)                                  \
 146        do {                                                            \
 147                unsigned long flags; /* may shadow */                   \
 148                WARN_ON_ONCE(!is_special_task_state(state_value));      \
 149                raw_spin_lock_irqsave(&current->pi_lock, flags);        \
 150                current->task_state_change = _THIS_IP_;                 \
 151                current->state = (state_value);                         \
 152                raw_spin_unlock_irqrestore(&current->pi_lock, flags);   \
 153        } while (0)
 154#else
 155/*
 156 * set_current_state() includes a barrier so that the write of current->state
 157 * is correctly serialised wrt the caller's subsequent test of whether to
 158 * actually sleep:
 159 *
 160 *   for (;;) {
 161 *      set_current_state(TASK_UNINTERRUPTIBLE);
 162 *      if (CONDITION)
 163 *         break;
 164 *
 165 *      schedule();
 166 *   }
 167 *   __set_current_state(TASK_RUNNING);
 168 *
 169 * If the caller does not need such serialisation (because, for instance, the
 170 * CONDITION test and condition change and wakeup are under the same lock) then
 171 * use __set_current_state().
 172 *
 173 * The above is typically ordered against the wakeup, which does:
 174 *
 175 *   CONDITION = 1;
 176 *   wake_up_state(p, TASK_UNINTERRUPTIBLE);
 177 *
 178 * where wake_up_state()/try_to_wake_up() executes a full memory barrier before
 179 * accessing p->state.
 180 *
 181 * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is,
 182 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
 183 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
 184 *
 185 * However, with slightly different timing the wakeup TASK_RUNNING store can
 186 * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not
 187 * a problem either because that will result in one extra go around the loop
 188 * and our @cond test will save the day.
 189 *
 190 * Also see the comments of try_to_wake_up().
 191 */
 192#define __set_current_state(state_value)                                \
 193        current->state = (state_value)
 194
 195#define set_current_state(state_value)                                  \
 196        smp_store_mb(current->state, (state_value))
 197
 198/*
 199 * set_special_state() should be used for those states when the blocking task
 200 * can not use the regular condition based wait-loop. In that case we must
 201 * serialize against wakeups such that any possible in-flight TASK_RUNNING stores
 202 * will not collide with our state change.
 203 */
 204#define set_special_state(state_value)                                  \
 205        do {                                                            \
 206                unsigned long flags; /* may shadow */                   \
 207                raw_spin_lock_irqsave(&current->pi_lock, flags);        \
 208                current->state = (state_value);                         \
 209                raw_spin_unlock_irqrestore(&current->pi_lock, flags);   \
 210        } while (0)
 211
 212#endif
 213
 214/* Task command name length: */
 215#define TASK_COMM_LEN                   16
 216
 217extern void scheduler_tick(void);
 218
 219#define MAX_SCHEDULE_TIMEOUT            LONG_MAX
 220
 221extern long schedule_timeout(long timeout);
 222extern long schedule_timeout_interruptible(long timeout);
 223extern long schedule_timeout_killable(long timeout);
 224extern long schedule_timeout_uninterruptible(long timeout);
 225extern long schedule_timeout_idle(long timeout);
 226asmlinkage void schedule(void);
 227extern void schedule_preempt_disabled(void);
 228asmlinkage void preempt_schedule_irq(void);
 229
 230extern int __must_check io_schedule_prepare(void);
 231extern void io_schedule_finish(int token);
 232extern long io_schedule_timeout(long timeout);
 233extern void io_schedule(void);
 234
 235/**
 236 * struct prev_cputime - snapshot of system and user cputime
 237 * @utime: time spent in user mode
 238 * @stime: time spent in system mode
 239 * @lock: protects the above two fields
 240 *
 241 * Stores previous user/system time values such that we can guarantee
 242 * monotonicity.
 243 */
 244struct prev_cputime {
 245#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 246        u64                             utime;
 247        u64                             stime;
 248        raw_spinlock_t                  lock;
 249#endif
 250};
 251
 252enum vtime_state {
 253        /* Task is sleeping or running in a CPU with VTIME inactive: */
 254        VTIME_INACTIVE = 0,
 255        /* Task is idle */
 256        VTIME_IDLE,
 257        /* Task runs in kernelspace in a CPU with VTIME active: */
 258        VTIME_SYS,
 259        /* Task runs in userspace in a CPU with VTIME active: */
 260        VTIME_USER,
 261        /* Task runs as guests in a CPU with VTIME active: */
 262        VTIME_GUEST,
 263};
 264
 265struct vtime {
 266        seqcount_t              seqcount;
 267        unsigned long long      starttime;
 268        enum vtime_state        state;
 269        unsigned int            cpu;
 270        u64                     utime;
 271        u64                     stime;
 272        u64                     gtime;
 273};
 274
 275/*
 276 * Utilization clamp constraints.
 277 * @UCLAMP_MIN: Minimum utilization
 278 * @UCLAMP_MAX: Maximum utilization
 279 * @UCLAMP_CNT: Utilization clamp constraints count
 280 */
 281enum uclamp_id {
 282        UCLAMP_MIN = 0,
 283        UCLAMP_MAX,
 284        UCLAMP_CNT
 285};
 286
 287#ifdef CONFIG_SMP
 288extern struct root_domain def_root_domain;
 289extern struct mutex sched_domains_mutex;
 290#endif
 291
 292struct sched_info {
 293#ifdef CONFIG_SCHED_INFO
 294        /* Cumulative counters: */
 295
 296        /* # of times we have run on this CPU: */
 297        unsigned long                   pcount;
 298
 299        /* Time spent waiting on a runqueue: */
 300        unsigned long long              run_delay;
 301
 302        /* Timestamps: */
 303
 304        /* When did we last run on a CPU? */
 305        unsigned long long              last_arrival;
 306
 307        /* When were we last queued to run? */
 308        unsigned long long              last_queued;
 309
 310#endif /* CONFIG_SCHED_INFO */
 311};
 312
 313/*
 314 * Integer metrics need fixed point arithmetic, e.g., sched/fair
 315 * has a few: load, load_avg, util_avg, freq, and capacity.
 316 *
 317 * We define a basic fixed point arithmetic range, and then formalize
 318 * all these metrics based on that basic range.
 319 */
 320# define SCHED_FIXEDPOINT_SHIFT         10
 321# define SCHED_FIXEDPOINT_SCALE         (1L << SCHED_FIXEDPOINT_SHIFT)
 322
 323/* Increase resolution of cpu_capacity calculations */
 324# define SCHED_CAPACITY_SHIFT           SCHED_FIXEDPOINT_SHIFT
 325# define SCHED_CAPACITY_SCALE           (1L << SCHED_CAPACITY_SHIFT)
 326
 327struct load_weight {
 328        unsigned long                   weight;
 329        u32                             inv_weight;
 330};
 331
 332/**
 333 * struct util_est - Estimation utilization of FAIR tasks
 334 * @enqueued: instantaneous estimated utilization of a task/cpu
 335 * @ewma:     the Exponential Weighted Moving Average (EWMA)
 336 *            utilization of a task
 337 *
 338 * Support data structure to track an Exponential Weighted Moving Average
 339 * (EWMA) of a FAIR task's utilization. New samples are added to the moving
 340 * average each time a task completes an activation. Sample's weight is chosen
 341 * so that the EWMA will be relatively insensitive to transient changes to the
 342 * task's workload.
 343 *
 344 * The enqueued attribute has a slightly different meaning for tasks and cpus:
 345 * - task:   the task's util_avg at last task dequeue time
 346 * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU
 347 * Thus, the util_est.enqueued of a task represents the contribution on the
 348 * estimated utilization of the CPU where that task is currently enqueued.
 349 *
 350 * Only for tasks we track a moving average of the past instantaneous
 351 * estimated utilization. This allows to absorb sporadic drops in utilization
 352 * of an otherwise almost periodic task.
 353 *
 354 * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg
 355 * updates. When a task is dequeued, its util_est should not be updated if its
 356 * util_avg has not been updated in the meantime.
 357 * This information is mapped into the MSB bit of util_est.enqueued at dequeue
 358 * time. Since max value of util_est.enqueued for a task is 1024 (PELT util_avg
 359 * for a task) it is safe to use MSB.
 360 */
 361struct util_est {
 362        unsigned int                    enqueued;
 363        unsigned int                    ewma;
 364#define UTIL_EST_WEIGHT_SHIFT           2
 365#define UTIL_AVG_UNCHANGED              0x80000000
 366} __attribute__((__aligned__(sizeof(u64))));
 367
 368/*
 369 * The load/runnable/util_avg accumulates an infinite geometric series
 370 * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c).
 371 *
 372 * [load_avg definition]
 373 *
 374 *   load_avg = runnable% * scale_load_down(load)
 375 *
 376 * [runnable_avg definition]
 377 *
 378 *   runnable_avg = runnable% * SCHED_CAPACITY_SCALE
 379 *
 380 * [util_avg definition]
 381 *
 382 *   util_avg = running% * SCHED_CAPACITY_SCALE
 383 *
 384 * where runnable% is the time ratio that a sched_entity is runnable and
 385 * running% the time ratio that a sched_entity is running.
 386 *
 387 * For cfs_rq, they are the aggregated values of all runnable and blocked
 388 * sched_entities.
 389 *
 390 * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU
 391 * capacity scaling. The scaling is done through the rq_clock_pelt that is used
 392 * for computing those signals (see update_rq_clock_pelt())
 393 *
 394 * N.B., the above ratios (runnable% and running%) themselves are in the
 395 * range of [0, 1]. To do fixed point arithmetics, we therefore scale them
 396 * to as large a range as necessary. This is for example reflected by
 397 * util_avg's SCHED_CAPACITY_SCALE.
 398 *
 399 * [Overflow issue]
 400 *
 401 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
 402 * with the highest load (=88761), always runnable on a single cfs_rq,
 403 * and should not overflow as the number already hits PID_MAX_LIMIT.
 404 *
 405 * For all other cases (including 32-bit kernels), struct load_weight's
 406 * weight will overflow first before we do, because:
 407 *
 408 *    Max(load_avg) <= Max(load.weight)
 409 *
 410 * Then it is the load_weight's responsibility to consider overflow
 411 * issues.
 412 */
 413struct sched_avg {
 414        u64                             last_update_time;
 415        u64                             load_sum;
 416        u64                             runnable_sum;
 417        u32                             util_sum;
 418        u32                             period_contrib;
 419        unsigned long                   load_avg;
 420        unsigned long                   runnable_avg;
 421        unsigned long                   util_avg;
 422        struct util_est                 util_est;
 423} ____cacheline_aligned;
 424
 425struct sched_statistics {
 426#ifdef CONFIG_SCHEDSTATS
 427        u64                             wait_start;
 428        u64                             wait_max;
 429        u64                             wait_count;
 430        u64                             wait_sum;
 431        u64                             iowait_count;
 432        u64                             iowait_sum;
 433
 434        u64                             sleep_start;
 435        u64                             sleep_max;
 436        s64                             sum_sleep_runtime;
 437
 438        u64                             block_start;
 439        u64                             block_max;
 440        u64                             exec_max;
 441        u64                             slice_max;
 442
 443        u64                             nr_migrations_cold;
 444        u64                             nr_failed_migrations_affine;
 445        u64                             nr_failed_migrations_running;
 446        u64                             nr_failed_migrations_hot;
 447        u64                             nr_forced_migrations;
 448
 449        u64                             nr_wakeups;
 450        u64                             nr_wakeups_sync;
 451        u64                             nr_wakeups_migrate;
 452        u64                             nr_wakeups_local;
 453        u64                             nr_wakeups_remote;
 454        u64                             nr_wakeups_affine;
 455        u64                             nr_wakeups_affine_attempts;
 456        u64                             nr_wakeups_passive;
 457        u64                             nr_wakeups_idle;
 458#endif
 459};
 460
 461struct sched_entity {
 462        /* For load-balancing: */
 463        struct load_weight              load;
 464        struct rb_node                  run_node;
 465        struct list_head                group_node;
 466        unsigned int                    on_rq;
 467
 468        u64                             exec_start;
 469        u64                             sum_exec_runtime;
 470        u64                             vruntime;
 471        u64                             prev_sum_exec_runtime;
 472
 473        u64                             nr_migrations;
 474
 475        struct sched_statistics         statistics;
 476
 477#ifdef CONFIG_FAIR_GROUP_SCHED
 478        int                             depth;
 479        struct sched_entity             *parent;
 480        /* rq on which this entity is (to be) queued: */
 481        struct cfs_rq                   *cfs_rq;
 482        /* rq "owned" by this entity/group: */
 483        struct cfs_rq                   *my_q;
 484        /* cached value of my_q->h_nr_running */
 485        unsigned long                   runnable_weight;
 486#endif
 487
 488#ifdef CONFIG_SMP
 489        /*
 490         * Per entity load average tracking.
 491         *
 492         * Put into separate cache line so it does not
 493         * collide with read-mostly values above.
 494         */
 495        struct sched_avg                avg;
 496#endif
 497};
 498
 499struct sched_rt_entity {
 500        struct list_head                run_list;
 501        unsigned long                   timeout;
 502        unsigned long                   watchdog_stamp;
 503        unsigned int                    time_slice;
 504        unsigned short                  on_rq;
 505        unsigned short                  on_list;
 506
 507        struct sched_rt_entity          *back;
 508#ifdef CONFIG_RT_GROUP_SCHED
 509        struct sched_rt_entity          *parent;
 510        /* rq on which this entity is (to be) queued: */
 511        struct rt_rq                    *rt_rq;
 512        /* rq "owned" by this entity/group: */
 513        struct rt_rq                    *my_q;
 514#endif
 515} __randomize_layout;
 516
 517struct sched_dl_entity {
 518        struct rb_node                  rb_node;
 519
 520        /*
 521         * Original scheduling parameters. Copied here from sched_attr
 522         * during sched_setattr(), they will remain the same until
 523         * the next sched_setattr().
 524         */
 525        u64                             dl_runtime;     /* Maximum runtime for each instance    */
 526        u64                             dl_deadline;    /* Relative deadline of each instance   */
 527        u64                             dl_period;      /* Separation of two instances (period) */
 528        u64                             dl_bw;          /* dl_runtime / dl_period               */
 529        u64                             dl_density;     /* dl_runtime / dl_deadline             */
 530
 531        /*
 532         * Actual scheduling parameters. Initialized with the values above,
 533         * they are continuously updated during task execution. Note that
 534         * the remaining runtime could be < 0 in case we are in overrun.
 535         */
 536        s64                             runtime;        /* Remaining runtime for this instance  */
 537        u64                             deadline;       /* Absolute deadline for this instance  */
 538        unsigned int                    flags;          /* Specifying the scheduler behaviour   */
 539
 540        /*
 541         * Some bool flags:
 542         *
 543         * @dl_throttled tells if we exhausted the runtime. If so, the
 544         * task has to wait for a replenishment to be performed at the
 545         * next firing of dl_timer.
 546         *
 547         * @dl_boosted tells if we are boosted due to DI. If so we are
 548         * outside bandwidth enforcement mechanism (but only until we
 549         * exit the critical section);
 550         *
 551         * @dl_yielded tells if task gave up the CPU before consuming
 552         * all its available runtime during the last job.
 553         *
 554         * @dl_non_contending tells if the task is inactive while still
 555         * contributing to the active utilization. In other words, it
 556         * indicates if the inactive timer has been armed and its handler
 557         * has not been executed yet. This flag is useful to avoid race
 558         * conditions between the inactive timer handler and the wakeup
 559         * code.
 560         *
 561         * @dl_overrun tells if the task asked to be informed about runtime
 562         * overruns.
 563         */
 564        unsigned int                    dl_throttled      : 1;
 565        unsigned int                    dl_yielded        : 1;
 566        unsigned int                    dl_non_contending : 1;
 567        unsigned int                    dl_overrun        : 1;
 568
 569        /*
 570         * Bandwidth enforcement timer. Each -deadline task has its
 571         * own bandwidth to be enforced, thus we need one timer per task.
 572         */
 573        struct hrtimer                  dl_timer;
 574
 575        /*
 576         * Inactive timer, responsible for decreasing the active utilization
 577         * at the "0-lag time". When a -deadline task blocks, it contributes
 578         * to GRUB's active utilization until the "0-lag time", hence a
 579         * timer is needed to decrease the active utilization at the correct
 580         * time.
 581         */
 582        struct hrtimer inactive_timer;
 583
 584#ifdef CONFIG_RT_MUTEXES
 585        /*
 586         * Priority Inheritance. When a DEADLINE scheduling entity is boosted
 587         * pi_se points to the donor, otherwise points to the dl_se it belongs
 588         * to (the original one/itself).
 589         */
 590        struct sched_dl_entity *pi_se;
 591#endif
 592};
 593
 594#ifdef CONFIG_UCLAMP_TASK
 595/* Number of utilization clamp buckets (shorter alias) */
 596#define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT
 597
 598/*
 599 * Utilization clamp for a scheduling entity
 600 * @value:              clamp value "assigned" to a se
 601 * @bucket_id:          bucket index corresponding to the "assigned" value
 602 * @active:             the se is currently refcounted in a rq's bucket
 603 * @user_defined:       the requested clamp value comes from user-space
 604 *
 605 * The bucket_id is the index of the clamp bucket matching the clamp value
 606 * which is pre-computed and stored to avoid expensive integer divisions from
 607 * the fast path.
 608 *
 609 * The active bit is set whenever a task has got an "effective" value assigned,
 610 * which can be different from the clamp value "requested" from user-space.
 611 * This allows to know a task is refcounted in the rq's bucket corresponding
 612 * to the "effective" bucket_id.
 613 *
 614 * The user_defined bit is set whenever a task has got a task-specific clamp
 615 * value requested from userspace, i.e. the system defaults apply to this task
 616 * just as a restriction. This allows to relax default clamps when a less
 617 * restrictive task-specific value has been requested, thus allowing to
 618 * implement a "nice" semantic. For example, a task running with a 20%
 619 * default boost can still drop its own boosting to 0%.
 620 */
 621struct uclamp_se {
 622        unsigned int value              : bits_per(SCHED_CAPACITY_SCALE);
 623        unsigned int bucket_id          : bits_per(UCLAMP_BUCKETS);
 624        unsigned int active             : 1;
 625        unsigned int user_defined       : 1;
 626};
 627#endif /* CONFIG_UCLAMP_TASK */
 628
 629union rcu_special {
 630        struct {
 631                u8                      blocked;
 632                u8                      need_qs;
 633                u8                      exp_hint; /* Hint for performance. */
 634                u8                      need_mb; /* Readers need smp_mb(). */
 635        } b; /* Bits. */
 636        u32 s; /* Set of bits. */
 637};
 638
 639enum perf_event_task_context {
 640        perf_invalid_context = -1,
 641        perf_hw_context = 0,
 642        perf_sw_context,
 643        perf_nr_task_contexts,
 644};
 645
 646struct wake_q_node {
 647        struct wake_q_node *next;
 648};
 649
 650struct kmap_ctrl {
 651#ifdef CONFIG_KMAP_LOCAL
 652        int                             idx;
 653        pte_t                           pteval[KM_MAX_IDX];
 654#endif
 655};
 656
 657struct task_struct {
 658#ifdef CONFIG_THREAD_INFO_IN_TASK
 659        /*
 660         * For reasons of header soup (see current_thread_info()), this
 661         * must be the first element of task_struct.
 662         */
 663        struct thread_info              thread_info;
 664#endif
 665        /* -1 unrunnable, 0 runnable, >0 stopped: */
 666        volatile long                   state;
 667
 668        /*
 669         * This begins the randomizable portion of task_struct. Only
 670         * scheduling-critical items should be added above here.
 671         */
 672        randomized_struct_fields_start
 673
 674        void                            *stack;
 675        refcount_t                      usage;
 676        /* Per task flags (PF_*), defined further below: */
 677        unsigned int                    flags;
 678        unsigned int                    ptrace;
 679
 680#ifdef CONFIG_SMP
 681        int                             on_cpu;
 682        struct __call_single_node       wake_entry;
 683#ifdef CONFIG_THREAD_INFO_IN_TASK
 684        /* Current CPU: */
 685        unsigned int                    cpu;
 686#endif
 687        unsigned int                    wakee_flips;
 688        unsigned long                   wakee_flip_decay_ts;
 689        struct task_struct              *last_wakee;
 690
 691        /*
 692         * recent_used_cpu is initially set as the last CPU used by a task
 693         * that wakes affine another task. Waker/wakee relationships can
 694         * push tasks around a CPU where each wakeup moves to the next one.
 695         * Tracking a recently used CPU allows a quick search for a recently
 696         * used CPU that may be idle.
 697         */
 698        int                             recent_used_cpu;
 699        int                             wake_cpu;
 700#endif
 701        int                             on_rq;
 702
 703        int                             prio;
 704        int                             static_prio;
 705        int                             normal_prio;
 706        unsigned int                    rt_priority;
 707
 708        const struct sched_class        *sched_class;
 709        struct sched_entity             se;
 710        struct sched_rt_entity          rt;
 711#ifdef CONFIG_CGROUP_SCHED
 712        struct task_group               *sched_task_group;
 713#endif
 714        struct sched_dl_entity          dl;
 715
 716#ifdef CONFIG_UCLAMP_TASK
 717        /*
 718         * Clamp values requested for a scheduling entity.
 719         * Must be updated with task_rq_lock() held.
 720         */
 721        struct uclamp_se                uclamp_req[UCLAMP_CNT];
 722        /*
 723         * Effective clamp values used for a scheduling entity.
 724         * Must be updated with task_rq_lock() held.
 725         */
 726        struct uclamp_se                uclamp[UCLAMP_CNT];
 727#endif
 728
 729#ifdef CONFIG_PREEMPT_NOTIFIERS
 730        /* List of struct preempt_notifier: */
 731        struct hlist_head               preempt_notifiers;
 732#endif
 733
 734#ifdef CONFIG_BLK_DEV_IO_TRACE
 735        unsigned int                    btrace_seq;
 736#endif
 737
 738        unsigned int                    policy;
 739        int                             nr_cpus_allowed;
 740        const cpumask_t                 *cpus_ptr;
 741        cpumask_t                       cpus_mask;
 742        void                            *migration_pending;
 743#ifdef CONFIG_SMP
 744        unsigned short                  migration_disabled;
 745#endif
 746        unsigned short                  migration_flags;
 747
 748#ifdef CONFIG_PREEMPT_RCU
 749        int                             rcu_read_lock_nesting;
 750        union rcu_special               rcu_read_unlock_special;
 751        struct list_head                rcu_node_entry;
 752        struct rcu_node                 *rcu_blocked_node;
 753#endif /* #ifdef CONFIG_PREEMPT_RCU */
 754
 755#ifdef CONFIG_TASKS_RCU
 756        unsigned long                   rcu_tasks_nvcsw;
 757        u8                              rcu_tasks_holdout;
 758        u8                              rcu_tasks_idx;
 759        int                             rcu_tasks_idle_cpu;
 760        struct list_head                rcu_tasks_holdout_list;
 761#endif /* #ifdef CONFIG_TASKS_RCU */
 762
 763#ifdef CONFIG_TASKS_TRACE_RCU
 764        int                             trc_reader_nesting;
 765        int                             trc_ipi_to_cpu;
 766        union rcu_special               trc_reader_special;
 767        bool                            trc_reader_checked;
 768        struct list_head                trc_holdout_list;
 769#endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
 770
 771        struct sched_info               sched_info;
 772
 773        struct list_head                tasks;
 774#ifdef CONFIG_SMP
 775        struct plist_node               pushable_tasks;
 776        struct rb_node                  pushable_dl_tasks;
 777#endif
 778
 779        struct mm_struct                *mm;
 780        struct mm_struct                *active_mm;
 781
 782        /* Per-thread vma caching: */
 783        struct vmacache                 vmacache;
 784
 785#ifdef SPLIT_RSS_COUNTING
 786        struct task_rss_stat            rss_stat;
 787#endif
 788        int                             exit_state;
 789        int                             exit_code;
 790        int                             exit_signal;
 791        /* The signal sent when the parent dies: */
 792        int                             pdeath_signal;
 793        /* JOBCTL_*, siglock protected: */
 794        unsigned long                   jobctl;
 795
 796        /* Used for emulating ABI behavior of previous Linux versions: */
 797        unsigned int                    personality;
 798
 799        /* Scheduler bits, serialized by scheduler locks: */
 800        unsigned                        sched_reset_on_fork:1;
 801        unsigned                        sched_contributes_to_load:1;
 802        unsigned                        sched_migrated:1;
 803#ifdef CONFIG_PSI
 804        unsigned                        sched_psi_wake_requeue:1;
 805#endif
 806
 807        /* Force alignment to the next boundary: */
 808        unsigned                        :0;
 809
 810        /* Unserialized, strictly 'current' */
 811
 812        /*
 813         * This field must not be in the scheduler word above due to wakelist
 814         * queueing no longer being serialized by p->on_cpu. However:
 815         *
 816         * p->XXX = X;                  ttwu()
 817         * schedule()                     if (p->on_rq && ..) // false
 818         *   smp_mb__after_spinlock();    if (smp_load_acquire(&p->on_cpu) && //true
 819         *   deactivate_task()                ttwu_queue_wakelist())
 820         *     p->on_rq = 0;                    p->sched_remote_wakeup = Y;
 821         *
 822         * guarantees all stores of 'current' are visible before
 823         * ->sched_remote_wakeup gets used, so it can be in this word.
 824         */
 825        unsigned                        sched_remote_wakeup:1;
 826
 827        /* Bit to tell LSMs we're in execve(): */
 828        unsigned                        in_execve:1;
 829        unsigned                        in_iowait:1;
 830#ifndef TIF_RESTORE_SIGMASK
 831        unsigned                        restore_sigmask:1;
 832#endif
 833#ifdef CONFIG_MEMCG
 834        unsigned                        in_user_fault:1;
 835#endif
 836#ifdef CONFIG_COMPAT_BRK
 837        unsigned                        brk_randomized:1;
 838#endif
 839#ifdef CONFIG_CGROUPS
 840        /* disallow userland-initiated cgroup migration */
 841        unsigned                        no_cgroup_migration:1;
 842        /* task is frozen/stopped (used by the cgroup freezer) */
 843        unsigned                        frozen:1;
 844#endif
 845#ifdef CONFIG_BLK_CGROUP
 846        unsigned                        use_memdelay:1;
 847#endif
 848#ifdef CONFIG_PSI
 849        /* Stalled due to lack of memory */
 850        unsigned                        in_memstall:1;
 851#endif
 852#ifdef CONFIG_PAGE_OWNER
 853        /* Used by page_owner=on to detect recursion in page tracking. */
 854        unsigned                        in_page_owner:1;
 855#endif
 856
 857        unsigned long                   atomic_flags; /* Flags requiring atomic access. */
 858
 859        struct restart_block            restart_block;
 860
 861        pid_t                           pid;
 862        pid_t                           tgid;
 863
 864#ifdef CONFIG_STACKPROTECTOR
 865        /* Canary value for the -fstack-protector GCC feature: */
 866        unsigned long                   stack_canary;
 867#endif
 868        /*
 869         * Pointers to the (original) parent process, youngest child, younger sibling,
 870         * older sibling, respectively.  (p->father can be replaced with
 871         * p->real_parent->pid)
 872         */
 873
 874        /* Real parent process: */
 875        struct task_struct __rcu        *real_parent;
 876
 877        /* Recipient of SIGCHLD, wait4() reports: */
 878        struct task_struct __rcu        *parent;
 879
 880        /*
 881         * Children/sibling form the list of natural children:
 882         */
 883        struct list_head                children;
 884        struct list_head                sibling;
 885        struct task_struct              *group_leader;
 886
 887        /*
 888         * 'ptraced' is the list of tasks this task is using ptrace() on.
 889         *
 890         * This includes both natural children and PTRACE_ATTACH targets.
 891         * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
 892         */
 893        struct list_head                ptraced;
 894        struct list_head                ptrace_entry;
 895
 896        /* PID/PID hash table linkage. */
 897        struct pid                      *thread_pid;
 898        struct hlist_node               pid_links[PIDTYPE_MAX];
 899        struct list_head                thread_group;
 900        struct list_head                thread_node;
 901
 902        struct completion               *vfork_done;
 903
 904        /* CLONE_CHILD_SETTID: */
 905        int __user                      *set_child_tid;
 906
 907        /* CLONE_CHILD_CLEARTID: */
 908        int __user                      *clear_child_tid;
 909
 910        /* PF_IO_WORKER */
 911        void                            *pf_io_worker;
 912
 913        u64                             utime;
 914        u64                             stime;
 915#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
 916        u64                             utimescaled;
 917        u64                             stimescaled;
 918#endif
 919        u64                             gtime;
 920        struct prev_cputime             prev_cputime;
 921#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
 922        struct vtime                    vtime;
 923#endif
 924
 925#ifdef CONFIG_NO_HZ_FULL
 926        atomic_t                        tick_dep_mask;
 927#endif
 928        /* Context switch counts: */
 929        unsigned long                   nvcsw;
 930        unsigned long                   nivcsw;
 931
 932        /* Monotonic time in nsecs: */
 933        u64                             start_time;
 934
 935        /* Boot based time in nsecs: */
 936        u64                             start_boottime;
 937
 938        /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
 939        unsigned long                   min_flt;
 940        unsigned long                   maj_flt;
 941
 942        /* Empty if CONFIG_POSIX_CPUTIMERS=n */
 943        struct posix_cputimers          posix_cputimers;
 944
 945#ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK
 946        struct posix_cputimers_work     posix_cputimers_work;
 947#endif
 948
 949        /* Process credentials: */
 950
 951        /* Tracer's credentials at attach: */
 952        const struct cred __rcu         *ptracer_cred;
 953
 954        /* Objective and real subjective task credentials (COW): */
 955        const struct cred __rcu         *real_cred;
 956
 957        /* Effective (overridable) subjective task credentials (COW): */
 958        const struct cred __rcu         *cred;
 959
 960#ifdef CONFIG_KEYS
 961        /* Cached requested key. */
 962        struct key                      *cached_requested_key;
 963#endif
 964
 965        /*
 966         * executable name, excluding path.
 967         *
 968         * - normally initialized setup_new_exec()
 969         * - access it with [gs]et_task_comm()
 970         * - lock it with task_lock()
 971         */
 972        char                            comm[TASK_COMM_LEN];
 973
 974        struct nameidata                *nameidata;
 975
 976#ifdef CONFIG_SYSVIPC
 977        struct sysv_sem                 sysvsem;
 978        struct sysv_shm                 sysvshm;
 979#endif
 980#ifdef CONFIG_DETECT_HUNG_TASK
 981        unsigned long                   last_switch_count;
 982        unsigned long                   last_switch_time;
 983#endif
 984        /* Filesystem information: */
 985        struct fs_struct                *fs;
 986
 987        /* Open file information: */
 988        struct files_struct             *files;
 989
 990#ifdef CONFIG_IO_URING
 991        struct io_uring_task            *io_uring;
 992#endif
 993
 994        /* Namespaces: */
 995        struct nsproxy                  *nsproxy;
 996
 997        /* Signal handlers: */
 998        struct signal_struct            *signal;
 999        struct sighand_struct __rcu             *sighand;
1000        sigset_t                        blocked;
1001        sigset_t                        real_blocked;
1002        /* Restored if set_restore_sigmask() was used: */
1003        sigset_t                        saved_sigmask;
1004        struct sigpending               pending;
1005        unsigned long                   sas_ss_sp;
1006        size_t                          sas_ss_size;
1007        unsigned int                    sas_ss_flags;
1008
1009        struct callback_head            *task_works;
1010
1011#ifdef CONFIG_AUDIT
1012#ifdef CONFIG_AUDITSYSCALL
1013        struct audit_context            *audit_context;
1014#endif
1015        kuid_t                          loginuid;
1016        unsigned int                    sessionid;
1017#endif
1018        struct seccomp                  seccomp;
1019        struct syscall_user_dispatch    syscall_dispatch;
1020
1021        /* Thread group tracking: */
1022        u64                             parent_exec_id;
1023        u64                             self_exec_id;
1024
1025        /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
1026        spinlock_t                      alloc_lock;
1027
1028        /* Protection of the PI data structures: */
1029        raw_spinlock_t                  pi_lock;
1030
1031        struct wake_q_node              wake_q;
1032
1033#ifdef CONFIG_RT_MUTEXES
1034        /* PI waiters blocked on a rt_mutex held by this task: */
1035        struct rb_root_cached           pi_waiters;
1036        /* Updated under owner's pi_lock and rq lock */
1037        struct task_struct              *pi_top_task;
1038        /* Deadlock detection and priority inheritance handling: */
1039        struct rt_mutex_waiter          *pi_blocked_on;
1040#endif
1041
1042#ifdef CONFIG_DEBUG_MUTEXES
1043        /* Mutex deadlock detection: */
1044        struct mutex_waiter             *blocked_on;
1045#endif
1046
1047#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1048        int                             non_block_count;
1049#endif
1050
1051#ifdef CONFIG_TRACE_IRQFLAGS
1052        struct irqtrace_events          irqtrace;
1053        unsigned int                    hardirq_threaded;
1054        u64                             hardirq_chain_key;
1055        int                             softirqs_enabled;
1056        int                             softirq_context;
1057        int                             irq_config;
1058#endif
1059#ifdef CONFIG_PREEMPT_RT
1060        int                             softirq_disable_cnt;
1061#endif
1062
1063#ifdef CONFIG_LOCKDEP
1064# define MAX_LOCK_DEPTH                 48UL
1065        u64                             curr_chain_key;
1066        int                             lockdep_depth;
1067        unsigned int                    lockdep_recursion;
1068        struct held_lock                held_locks[MAX_LOCK_DEPTH];
1069#endif
1070
1071#if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP)
1072        unsigned int                    in_ubsan;
1073#endif
1074
1075        /* Journalling filesystem info: */
1076        void                            *journal_info;
1077
1078        /* Stacked block device info: */
1079        struct bio_list                 *bio_list;
1080
1081#ifdef CONFIG_BLOCK
1082        /* Stack plugging: */
1083        struct blk_plug                 *plug;
1084#endif
1085
1086        /* VM state: */
1087        struct reclaim_state            *reclaim_state;
1088
1089        struct backing_dev_info         *backing_dev_info;
1090
1091        struct io_context               *io_context;
1092
1093#ifdef CONFIG_COMPACTION
1094        struct capture_control          *capture_control;
1095#endif
1096        /* Ptrace state: */
1097        unsigned long                   ptrace_message;
1098        kernel_siginfo_t                *last_siginfo;
1099
1100        struct task_io_accounting       ioac;
1101#ifdef CONFIG_PSI
1102        /* Pressure stall state */
1103        unsigned int                    psi_flags;
1104#endif
1105#ifdef CONFIG_TASK_XACCT
1106        /* Accumulated RSS usage: */
1107        u64                             acct_rss_mem1;
1108        /* Accumulated virtual memory usage: */
1109        u64                             acct_vm_mem1;
1110        /* stime + utime since last update: */
1111        u64                             acct_timexpd;
1112#endif
1113#ifdef CONFIG_CPUSETS
1114        /* Protected by ->alloc_lock: */
1115        nodemask_t                      mems_allowed;
1116        /* Sequence number to catch updates: */
1117        seqcount_spinlock_t             mems_allowed_seq;
1118        int                             cpuset_mem_spread_rotor;
1119        int                             cpuset_slab_spread_rotor;
1120#endif
1121#ifdef CONFIG_CGROUPS
1122        /* Control Group info protected by css_set_lock: */
1123        struct css_set __rcu            *cgroups;
1124        /* cg_list protected by css_set_lock and tsk->alloc_lock: */
1125        struct list_head                cg_list;
1126#endif
1127#ifdef CONFIG_X86_CPU_RESCTRL
1128        u32                             closid;
1129        u32                             rmid;
1130#endif
1131#ifdef CONFIG_FUTEX
1132        struct robust_list_head __user  *robust_list;
1133#ifdef CONFIG_COMPAT
1134        struct compat_robust_list_head __user *compat_robust_list;
1135#endif
1136        struct list_head                pi_state_list;
1137        struct futex_pi_state           *pi_state_cache;
1138        struct mutex                    futex_exit_mutex;
1139        unsigned int                    futex_state;
1140#endif
1141#ifdef CONFIG_PERF_EVENTS
1142        struct perf_event_context       *perf_event_ctxp[perf_nr_task_contexts];
1143        struct mutex                    perf_event_mutex;
1144        struct list_head                perf_event_list;
1145#endif
1146#ifdef CONFIG_DEBUG_PREEMPT
1147        unsigned long                   preempt_disable_ip;
1148#endif
1149#ifdef CONFIG_NUMA
1150        /* Protected by alloc_lock: */
1151        struct mempolicy                *mempolicy;
1152        short                           il_prev;
1153        short                           pref_node_fork;
1154#endif
1155#ifdef CONFIG_NUMA_BALANCING
1156        int                             numa_scan_seq;
1157        unsigned int                    numa_scan_period;
1158        unsigned int                    numa_scan_period_max;
1159        int                             numa_preferred_nid;
1160        unsigned long                   numa_migrate_retry;
1161        /* Migration stamp: */
1162        u64                             node_stamp;
1163        u64                             last_task_numa_placement;
1164        u64                             last_sum_exec_runtime;
1165        struct callback_head            numa_work;
1166
1167        /*
1168         * This pointer is only modified for current in syscall and
1169         * pagefault context (and for tasks being destroyed), so it can be read
1170         * from any of the following contexts:
1171         *  - RCU read-side critical section
1172         *  - current->numa_group from everywhere
1173         *  - task's runqueue locked, task not running
1174         */
1175        struct numa_group __rcu         *numa_group;
1176
1177        /*
1178         * numa_faults is an array split into four regions:
1179         * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1180         * in this precise order.
1181         *
1182         * faults_memory: Exponential decaying average of faults on a per-node
1183         * basis. Scheduling placement decisions are made based on these
1184         * counts. The values remain static for the duration of a PTE scan.
1185         * faults_cpu: Track the nodes the process was running on when a NUMA
1186         * hinting fault was incurred.
1187         * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1188         * during the current scan window. When the scan completes, the counts
1189         * in faults_memory and faults_cpu decay and these values are copied.
1190         */
1191        unsigned long                   *numa_faults;
1192        unsigned long                   total_numa_faults;
1193
1194        /*
1195         * numa_faults_locality tracks if faults recorded during the last
1196         * scan window were remote/local or failed to migrate. The task scan
1197         * period is adapted based on the locality of the faults with different
1198         * weights depending on whether they were shared or private faults
1199         */
1200        unsigned long                   numa_faults_locality[3];
1201
1202        unsigned long                   numa_pages_migrated;
1203#endif /* CONFIG_NUMA_BALANCING */
1204
1205#ifdef CONFIG_RSEQ
1206        struct rseq __user *rseq;
1207        u32 rseq_sig;
1208        /*
1209         * RmW on rseq_event_mask must be performed atomically
1210         * with respect to preemption.
1211         */
1212        unsigned long rseq_event_mask;
1213#endif
1214
1215        struct tlbflush_unmap_batch     tlb_ubc;
1216
1217        union {
1218                refcount_t              rcu_users;
1219                struct rcu_head         rcu;
1220        };
1221
1222        /* Cache last used pipe for splice(): */
1223        struct pipe_inode_info          *splice_pipe;
1224
1225        struct page_frag                task_frag;
1226
1227#ifdef CONFIG_TASK_DELAY_ACCT
1228        struct task_delay_info          *delays;
1229#endif
1230
1231#ifdef CONFIG_FAULT_INJECTION
1232        int                             make_it_fail;
1233        unsigned int                    fail_nth;
1234#endif
1235        /*
1236         * When (nr_dirtied >= nr_dirtied_pause), it's time to call
1237         * balance_dirty_pages() for a dirty throttling pause:
1238         */
1239        int                             nr_dirtied;
1240        int                             nr_dirtied_pause;
1241        /* Start of a write-and-pause period: */
1242        unsigned long                   dirty_paused_when;
1243
1244#ifdef CONFIG_LATENCYTOP
1245        int                             latency_record_count;
1246        struct latency_record           latency_record[LT_SAVECOUNT];
1247#endif
1248        /*
1249         * Time slack values; these are used to round up poll() and
1250         * select() etc timeout values. These are in nanoseconds.
1251         */
1252        u64                             timer_slack_ns;
1253        u64                             default_timer_slack_ns;
1254
1255#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
1256        unsigned int                    kasan_depth;
1257#endif
1258
1259#ifdef CONFIG_KCSAN
1260        struct kcsan_ctx                kcsan_ctx;
1261#ifdef CONFIG_TRACE_IRQFLAGS
1262        struct irqtrace_events          kcsan_save_irqtrace;
1263#endif
1264#endif
1265
1266#if IS_ENABLED(CONFIG_KUNIT)
1267        struct kunit                    *kunit_test;
1268#endif
1269
1270#ifdef CONFIG_FUNCTION_GRAPH_TRACER
1271        /* Index of current stored address in ret_stack: */
1272        int                             curr_ret_stack;
1273        int                             curr_ret_depth;
1274
1275        /* Stack of return addresses for return function tracing: */
1276        struct ftrace_ret_stack         *ret_stack;
1277
1278        /* Timestamp for last schedule: */
1279        unsigned long long              ftrace_timestamp;
1280
1281        /*
1282         * Number of functions that haven't been traced
1283         * because of depth overrun:
1284         */
1285        atomic_t                        trace_overrun;
1286
1287        /* Pause tracing: */
1288        atomic_t                        tracing_graph_pause;
1289#endif
1290
1291#ifdef CONFIG_TRACING
1292        /* State flags for use by tracers: */
1293        unsigned long                   trace;
1294
1295        /* Bitmask and counter of trace recursion: */
1296        unsigned long                   trace_recursion;
1297#endif /* CONFIG_TRACING */
1298
1299#ifdef CONFIG_KCOV
1300        /* See kernel/kcov.c for more details. */
1301
1302        /* Coverage collection mode enabled for this task (0 if disabled): */
1303        unsigned int                    kcov_mode;
1304
1305        /* Size of the kcov_area: */
1306        unsigned int                    kcov_size;
1307
1308        /* Buffer for coverage collection: */
1309        void                            *kcov_area;
1310
1311        /* KCOV descriptor wired with this task or NULL: */
1312        struct kcov                     *kcov;
1313
1314        /* KCOV common handle for remote coverage collection: */
1315        u64                             kcov_handle;
1316
1317        /* KCOV sequence number: */
1318        int                             kcov_sequence;
1319
1320        /* Collect coverage from softirq context: */
1321        unsigned int                    kcov_softirq;
1322#endif
1323
1324#ifdef CONFIG_MEMCG
1325        struct mem_cgroup               *memcg_in_oom;
1326        gfp_t                           memcg_oom_gfp_mask;
1327        int                             memcg_oom_order;
1328
1329        /* Number of pages to reclaim on returning to userland: */
1330        unsigned int                    memcg_nr_pages_over_high;
1331
1332        /* Used by memcontrol for targeted memcg charge: */
1333        struct mem_cgroup               *active_memcg;
1334#endif
1335
1336#ifdef CONFIG_BLK_CGROUP
1337        struct request_queue            *throttle_queue;
1338#endif
1339
1340#ifdef CONFIG_UPROBES
1341        struct uprobe_task              *utask;
1342#endif
1343#if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1344        unsigned int                    sequential_io;
1345        unsigned int                    sequential_io_avg;
1346#endif
1347        struct kmap_ctrl                kmap_ctrl;
1348#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1349        unsigned long                   task_state_change;
1350#endif
1351        int                             pagefault_disabled;
1352#ifdef CONFIG_MMU
1353        struct task_struct              *oom_reaper_list;
1354#endif
1355#ifdef CONFIG_VMAP_STACK
1356        struct vm_struct                *stack_vm_area;
1357#endif
1358#ifdef CONFIG_THREAD_INFO_IN_TASK
1359        /* A live task holds one reference: */
1360        refcount_t                      stack_refcount;
1361#endif
1362#ifdef CONFIG_LIVEPATCH
1363        int patch_state;
1364#endif
1365#ifdef CONFIG_SECURITY
1366        /* Used by LSM modules for access restriction: */
1367        void                            *security;
1368#endif
1369#ifdef CONFIG_BPF_SYSCALL
1370        /* Used by BPF task local storage */
1371        struct bpf_local_storage __rcu  *bpf_storage;
1372#endif
1373
1374#ifdef CONFIG_GCC_PLUGIN_STACKLEAK
1375        unsigned long                   lowest_stack;
1376        unsigned long                   prev_lowest_stack;
1377#endif
1378
1379#ifdef CONFIG_X86_MCE
1380        void __user                     *mce_vaddr;
1381        __u64                           mce_kflags;
1382        u64                             mce_addr;
1383        __u64                           mce_ripv : 1,
1384                                        mce_whole_page : 1,
1385                                        __mce_reserved : 62;
1386        struct callback_head            mce_kill_me;
1387#endif
1388
1389#ifdef CONFIG_KRETPROBES
1390        struct llist_head               kretprobe_instances;
1391#endif
1392
1393        /*
1394         * New fields for task_struct should be added above here, so that
1395         * they are included in the randomized portion of task_struct.
1396         */
1397        randomized_struct_fields_end
1398
1399        /* CPU-specific state of this task: */
1400        struct thread_struct            thread;
1401
1402        /*
1403         * WARNING: on x86, 'thread_struct' contains a variable-sized
1404         * structure.  It *MUST* be at the end of 'task_struct'.
1405         *
1406         * Do not put anything below here!
1407         */
1408};
1409
1410static inline struct pid *task_pid(struct task_struct *task)
1411{
1412        return task->thread_pid;
1413}
1414
1415/*
1416 * the helpers to get the task's different pids as they are seen
1417 * from various namespaces
1418 *
1419 * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1420 * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1421 *                     current.
1422 * task_xid_nr_ns()  : id seen from the ns specified;
1423 *
1424 * see also pid_nr() etc in include/linux/pid.h
1425 */
1426pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns);
1427
1428static inline pid_t task_pid_nr(struct task_struct *tsk)
1429{
1430        return tsk->pid;
1431}
1432
1433static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1434{
1435        return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1436}
1437
1438static inline pid_t task_pid_vnr(struct task_struct *tsk)
1439{
1440        return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1441}
1442
1443
1444static inline pid_t task_tgid_nr(struct task_struct *tsk)
1445{
1446        return tsk->tgid;
1447}
1448
1449/**
1450 * pid_alive - check that a task structure is not stale
1451 * @p: Task structure to be checked.
1452 *
1453 * Test if a process is not yet dead (at most zombie state)
1454 * If pid_alive fails, then pointers within the task structure
1455 * can be stale and must not be dereferenced.
1456 *
1457 * Return: 1 if the process is alive. 0 otherwise.
1458 */
1459static inline int pid_alive(const struct task_struct *p)
1460{
1461        return p->thread_pid != NULL;
1462}
1463
1464static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1465{
1466        return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1467}
1468
1469static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1470{
1471        return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1472}
1473
1474
1475static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1476{
1477        return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1478}
1479
1480static inline pid_t task_session_vnr(struct task_struct *tsk)
1481{
1482        return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1483}
1484
1485static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1486{
1487        return __task_pid_nr_ns(tsk, PIDTYPE_TGID, ns);
1488}
1489
1490static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1491{
1492        return __task_pid_nr_ns(tsk, PIDTYPE_TGID, NULL);
1493}
1494
1495static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1496{
1497        pid_t pid = 0;
1498
1499        rcu_read_lock();
1500        if (pid_alive(tsk))
1501                pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1502        rcu_read_unlock();
1503
1504        return pid;
1505}
1506
1507static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1508{
1509        return task_ppid_nr_ns(tsk, &init_pid_ns);
1510}
1511
1512/* Obsolete, do not use: */
1513static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1514{
1515        return task_pgrp_nr_ns(tsk, &init_pid_ns);
1516}
1517
1518#define TASK_REPORT_IDLE        (TASK_REPORT + 1)
1519#define TASK_REPORT_MAX         (TASK_REPORT_IDLE << 1)
1520
1521static inline unsigned int task_state_index(struct task_struct *tsk)
1522{
1523        unsigned int tsk_state = READ_ONCE(tsk->state);
1524        unsigned int state = (tsk_state | tsk->exit_state) & TASK_REPORT;
1525
1526        BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX);
1527
1528        if (tsk_state == TASK_IDLE)
1529                state = TASK_REPORT_IDLE;
1530
1531        return fls(state);
1532}
1533
1534static inline char task_index_to_char(unsigned int state)
1535{
1536        static const char state_char[] = "RSDTtXZPI";
1537
1538        BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1);
1539
1540        return state_char[state];
1541}
1542
1543static inline char task_state_to_char(struct task_struct *tsk)
1544{
1545        return task_index_to_char(task_state_index(tsk));
1546}
1547
1548/**
1549 * is_global_init - check if a task structure is init. Since init
1550 * is free to have sub-threads we need to check tgid.
1551 * @tsk: Task structure to be checked.
1552 *
1553 * Check if a task structure is the first user space task the kernel created.
1554 *
1555 * Return: 1 if the task structure is init. 0 otherwise.
1556 */
1557static inline int is_global_init(struct task_struct *tsk)
1558{
1559        return task_tgid_nr(tsk) == 1;
1560}
1561
1562extern struct pid *cad_pid;
1563
1564/*
1565 * Per process flags
1566 */
1567#define PF_VCPU                 0x00000001      /* I'm a virtual CPU */
1568#define PF_IDLE                 0x00000002      /* I am an IDLE thread */
1569#define PF_EXITING              0x00000004      /* Getting shut down */
1570#define PF_IO_WORKER            0x00000010      /* Task is an IO worker */
1571#define PF_WQ_WORKER            0x00000020      /* I'm a workqueue worker */
1572#define PF_FORKNOEXEC           0x00000040      /* Forked but didn't exec */
1573#define PF_MCE_PROCESS          0x00000080      /* Process policy on mce errors */
1574#define PF_SUPERPRIV            0x00000100      /* Used super-user privileges */
1575#define PF_DUMPCORE             0x00000200      /* Dumped core */
1576#define PF_SIGNALED             0x00000400      /* Killed by a signal */
1577#define PF_MEMALLOC             0x00000800      /* Allocating memory */
1578#define PF_NPROC_EXCEEDED       0x00001000      /* set_user() noticed that RLIMIT_NPROC was exceeded */
1579#define PF_USED_MATH            0x00002000      /* If unset the fpu must be initialized before use */
1580#define PF_USED_ASYNC           0x00004000      /* Used async_schedule*(), used by module init */
1581#define PF_NOFREEZE             0x00008000      /* This thread should not be frozen */
1582#define PF_FROZEN               0x00010000      /* Frozen for system suspend */
1583#define PF_KSWAPD               0x00020000      /* I am kswapd */
1584#define PF_MEMALLOC_NOFS        0x00040000      /* All allocation requests will inherit GFP_NOFS */
1585#define PF_MEMALLOC_NOIO        0x00080000      /* All allocation requests will inherit GFP_NOIO */
1586#define PF_LOCAL_THROTTLE       0x00100000      /* Throttle writes only against the bdi I write to,
1587                                                 * I am cleaning dirty pages from some other bdi. */
1588#define PF_KTHREAD              0x00200000      /* I am a kernel thread */
1589#define PF_RANDOMIZE            0x00400000      /* Randomize virtual address space */
1590#define PF_SWAPWRITE            0x00800000      /* Allowed to write to swap */
1591#define PF_NO_SETAFFINITY       0x04000000      /* Userland is not allowed to meddle with cpus_mask */
1592#define PF_MCE_EARLY            0x08000000      /* Early kill for mce process policy */
1593#define PF_MEMALLOC_PIN         0x10000000      /* Allocation context constrained to zones which allow long term pinning. */
1594#define PF_FREEZER_SKIP         0x40000000      /* Freezer should not count it as freezable */
1595#define PF_SUSPEND_TASK         0x80000000      /* This thread called freeze_processes() and should not be frozen */
1596
1597/*
1598 * Only the _current_ task can read/write to tsk->flags, but other
1599 * tasks can access tsk->flags in readonly mode for example
1600 * with tsk_used_math (like during threaded core dumping).
1601 * There is however an exception to this rule during ptrace
1602 * or during fork: the ptracer task is allowed to write to the
1603 * child->flags of its traced child (same goes for fork, the parent
1604 * can write to the child->flags), because we're guaranteed the
1605 * child is not running and in turn not changing child->flags
1606 * at the same time the parent does it.
1607 */
1608#define clear_stopped_child_used_math(child)    do { (child)->flags &= ~PF_USED_MATH; } while (0)
1609#define set_stopped_child_used_math(child)      do { (child)->flags |= PF_USED_MATH; } while (0)
1610#define clear_used_math()                       clear_stopped_child_used_math(current)
1611#define set_used_math()                         set_stopped_child_used_math(current)
1612
1613#define conditional_stopped_child_used_math(condition, child) \
1614        do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1615
1616#define conditional_used_math(condition)        conditional_stopped_child_used_math(condition, current)
1617
1618#define copy_to_stopped_child_used_math(child) \
1619        do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1620
1621/* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1622#define tsk_used_math(p)                        ((p)->flags & PF_USED_MATH)
1623#define used_math()                             tsk_used_math(current)
1624
1625static inline bool is_percpu_thread(void)
1626{
1627#ifdef CONFIG_SMP
1628        return (current->flags & PF_NO_SETAFFINITY) &&
1629                (current->nr_cpus_allowed  == 1);
1630#else
1631        return true;
1632#endif
1633}
1634
1635/* Per-process atomic flags. */
1636#define PFA_NO_NEW_PRIVS                0       /* May not gain new privileges. */
1637#define PFA_SPREAD_PAGE                 1       /* Spread page cache over cpuset */
1638#define PFA_SPREAD_SLAB                 2       /* Spread some slab caches over cpuset */
1639#define PFA_SPEC_SSB_DISABLE            3       /* Speculative Store Bypass disabled */
1640#define PFA_SPEC_SSB_FORCE_DISABLE      4       /* Speculative Store Bypass force disabled*/
1641#define PFA_SPEC_IB_DISABLE             5       /* Indirect branch speculation restricted */
1642#define PFA_SPEC_IB_FORCE_DISABLE       6       /* Indirect branch speculation permanently restricted */
1643#define PFA_SPEC_SSB_NOEXEC             7       /* Speculative Store Bypass clear on execve() */
1644
1645#define TASK_PFA_TEST(name, func)                                       \
1646        static inline bool task_##func(struct task_struct *p)           \
1647        { return test_bit(PFA_##name, &p->atomic_flags); }
1648
1649#define TASK_PFA_SET(name, func)                                        \
1650        static inline void task_set_##func(struct task_struct *p)       \
1651        { set_bit(PFA_##name, &p->atomic_flags); }
1652
1653#define TASK_PFA_CLEAR(name, func)                                      \
1654        static inline void task_clear_##func(struct task_struct *p)     \
1655        { clear_bit(PFA_##name, &p->atomic_flags); }
1656
1657TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
1658TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
1659
1660TASK_PFA_TEST(SPREAD_PAGE, spread_page)
1661TASK_PFA_SET(SPREAD_PAGE, spread_page)
1662TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
1663
1664TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
1665TASK_PFA_SET(SPREAD_SLAB, spread_slab)
1666TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
1667
1668TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable)
1669TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable)
1670TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable)
1671
1672TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1673TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1674TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1675
1676TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1677TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1678
1679TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable)
1680TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable)
1681TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable)
1682
1683TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1684TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1685
1686static inline void
1687current_restore_flags(unsigned long orig_flags, unsigned long flags)
1688{
1689        current->flags &= ~flags;
1690        current->flags |= orig_flags & flags;
1691}
1692
1693extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
1694extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed);
1695#ifdef CONFIG_SMP
1696extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
1697extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
1698#else
1699static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
1700{
1701}
1702static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
1703{
1704        if (!cpumask_test_cpu(0, new_mask))
1705                return -EINVAL;
1706        return 0;
1707}
1708#endif
1709
1710extern int yield_to(struct task_struct *p, bool preempt);
1711extern void set_user_nice(struct task_struct *p, long nice);
1712extern int task_prio(const struct task_struct *p);
1713
1714/**
1715 * task_nice - return the nice value of a given task.
1716 * @p: the task in question.
1717 *
1718 * Return: The nice value [ -20 ... 0 ... 19 ].
1719 */
1720static inline int task_nice(const struct task_struct *p)
1721{
1722        return PRIO_TO_NICE((p)->static_prio);
1723}
1724
1725extern int can_nice(const struct task_struct *p, const int nice);
1726extern int task_curr(const struct task_struct *p);
1727extern int idle_cpu(int cpu);
1728extern int available_idle_cpu(int cpu);
1729extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *);
1730extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *);
1731extern void sched_set_fifo(struct task_struct *p);
1732extern void sched_set_fifo_low(struct task_struct *p);
1733extern void sched_set_normal(struct task_struct *p, int nice);
1734extern int sched_setattr(struct task_struct *, const struct sched_attr *);
1735extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *);
1736extern struct task_struct *idle_task(int cpu);
1737
1738/**
1739 * is_idle_task - is the specified task an idle task?
1740 * @p: the task in question.
1741 *
1742 * Return: 1 if @p is an idle task. 0 otherwise.
1743 */
1744static __always_inline bool is_idle_task(const struct task_struct *p)
1745{
1746        return !!(p->flags & PF_IDLE);
1747}
1748
1749extern struct task_struct *curr_task(int cpu);
1750extern void ia64_set_curr_task(int cpu, struct task_struct *p);
1751
1752void yield(void);
1753
1754union thread_union {
1755#ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK
1756        struct task_struct task;
1757#endif
1758#ifndef CONFIG_THREAD_INFO_IN_TASK
1759        struct thread_info thread_info;
1760#endif
1761        unsigned long stack[THREAD_SIZE/sizeof(long)];
1762};
1763
1764#ifndef CONFIG_THREAD_INFO_IN_TASK
1765extern struct thread_info init_thread_info;
1766#endif
1767
1768extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
1769
1770#ifdef CONFIG_THREAD_INFO_IN_TASK
1771static inline struct thread_info *task_thread_info(struct task_struct *task)
1772{
1773        return &task->thread_info;
1774}
1775#elif !defined(__HAVE_THREAD_FUNCTIONS)
1776# define task_thread_info(task) ((struct thread_info *)(task)->stack)
1777#endif
1778
1779/*
1780 * find a task by one of its numerical ids
1781 *
1782 * find_task_by_pid_ns():
1783 *      finds a task by its pid in the specified namespace
1784 * find_task_by_vpid():
1785 *      finds a task by its virtual pid
1786 *
1787 * see also find_vpid() etc in include/linux/pid.h
1788 */
1789
1790extern struct task_struct *find_task_by_vpid(pid_t nr);
1791extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns);
1792
1793/*
1794 * find a task by its virtual pid and get the task struct
1795 */
1796extern struct task_struct *find_get_task_by_vpid(pid_t nr);
1797
1798extern int wake_up_state(struct task_struct *tsk, unsigned int state);
1799extern int wake_up_process(struct task_struct *tsk);
1800extern void wake_up_new_task(struct task_struct *tsk);
1801
1802#ifdef CONFIG_SMP
1803extern void kick_process(struct task_struct *tsk);
1804#else
1805static inline void kick_process(struct task_struct *tsk) { }
1806#endif
1807
1808extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
1809
1810static inline void set_task_comm(struct task_struct *tsk, const char *from)
1811{
1812        __set_task_comm(tsk, from, false);
1813}
1814
1815extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk);
1816#define get_task_comm(buf, tsk) ({                      \
1817        BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN);     \
1818        __get_task_comm(buf, sizeof(buf), tsk);         \
1819})
1820
1821#ifdef CONFIG_SMP
1822static __always_inline void scheduler_ipi(void)
1823{
1824        /*
1825         * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting
1826         * TIF_NEED_RESCHED remotely (for the first time) will also send
1827         * this IPI.
1828         */
1829        preempt_fold_need_resched();
1830}
1831extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
1832#else
1833static inline void scheduler_ipi(void) { }
1834static inline unsigned long wait_task_inactive(struct task_struct *p, long match_state)
1835{
1836        return 1;
1837}
1838#endif
1839
1840/*
1841 * Set thread flags in other task's structures.
1842 * See asm/thread_info.h for TIF_xxxx flags available:
1843 */
1844static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
1845{
1846        set_ti_thread_flag(task_thread_info(tsk), flag);
1847}
1848
1849static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1850{
1851        clear_ti_thread_flag(task_thread_info(tsk), flag);
1852}
1853
1854static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag,
1855                                          bool value)
1856{
1857        update_ti_thread_flag(task_thread_info(tsk), flag, value);
1858}
1859
1860static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
1861{
1862        return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
1863}
1864
1865static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1866{
1867        return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
1868}
1869
1870static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
1871{
1872        return test_ti_thread_flag(task_thread_info(tsk), flag);
1873}
1874
1875static inline void set_tsk_need_resched(struct task_struct *tsk)
1876{
1877        set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1878}
1879
1880static inline void clear_tsk_need_resched(struct task_struct *tsk)
1881{
1882        clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1883}
1884
1885static inline int test_tsk_need_resched(struct task_struct *tsk)
1886{
1887        return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
1888}
1889
1890/*
1891 * cond_resched() and cond_resched_lock(): latency reduction via
1892 * explicit rescheduling in places that are safe. The return
1893 * value indicates whether a reschedule was done in fact.
1894 * cond_resched_lock() will drop the spinlock before scheduling,
1895 */
1896#if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC)
1897extern int __cond_resched(void);
1898
1899#ifdef CONFIG_PREEMPT_DYNAMIC
1900
1901DECLARE_STATIC_CALL(cond_resched, __cond_resched);
1902
1903static __always_inline int _cond_resched(void)
1904{
1905        return static_call_mod(cond_resched)();
1906}
1907
1908#else
1909
1910static inline int _cond_resched(void)
1911{
1912        return __cond_resched();
1913}
1914
1915#endif /* CONFIG_PREEMPT_DYNAMIC */
1916
1917#else
1918
1919static inline int _cond_resched(void) { return 0; }
1920
1921#endif /* !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) */
1922
1923#define cond_resched() ({                       \
1924        ___might_sleep(__FILE__, __LINE__, 0);  \
1925        _cond_resched();                        \
1926})
1927
1928extern int __cond_resched_lock(spinlock_t *lock);
1929extern int __cond_resched_rwlock_read(rwlock_t *lock);
1930extern int __cond_resched_rwlock_write(rwlock_t *lock);
1931
1932#define cond_resched_lock(lock) ({                              \
1933        ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
1934        __cond_resched_lock(lock);                              \
1935})
1936
1937#define cond_resched_rwlock_read(lock) ({                       \
1938        __might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET); \
1939        __cond_resched_rwlock_read(lock);                       \
1940})
1941
1942#define cond_resched_rwlock_write(lock) ({                      \
1943        __might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET); \
1944        __cond_resched_rwlock_write(lock);                      \
1945})
1946
1947static inline void cond_resched_rcu(void)
1948{
1949#if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
1950        rcu_read_unlock();
1951        cond_resched();
1952        rcu_read_lock();
1953#endif
1954}
1955
1956/*
1957 * Does a critical section need to be broken due to another
1958 * task waiting?: (technically does not depend on CONFIG_PREEMPTION,
1959 * but a general need for low latency)
1960 */
1961static inline int spin_needbreak(spinlock_t *lock)
1962{
1963#ifdef CONFIG_PREEMPTION
1964        return spin_is_contended(lock);
1965#else
1966        return 0;
1967#endif
1968}
1969
1970/*
1971 * Check if a rwlock is contended.
1972 * Returns non-zero if there is another task waiting on the rwlock.
1973 * Returns zero if the lock is not contended or the system / underlying
1974 * rwlock implementation does not support contention detection.
1975 * Technically does not depend on CONFIG_PREEMPTION, but a general need
1976 * for low latency.
1977 */
1978static inline int rwlock_needbreak(rwlock_t *lock)
1979{
1980#ifdef CONFIG_PREEMPTION
1981        return rwlock_is_contended(lock);
1982#else
1983        return 0;
1984#endif
1985}
1986
1987static __always_inline bool need_resched(void)
1988{
1989        return unlikely(tif_need_resched());
1990}
1991
1992/*
1993 * Wrappers for p->thread_info->cpu access. No-op on UP.
1994 */
1995#ifdef CONFIG_SMP
1996
1997static inline unsigned int task_cpu(const struct task_struct *p)
1998{
1999#ifdef CONFIG_THREAD_INFO_IN_TASK
2000        return READ_ONCE(p->cpu);
2001#else
2002        return READ_ONCE(task_thread_info(p)->cpu);
2003#endif
2004}
2005
2006extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2007
2008#else
2009
2010static inline unsigned int task_cpu(const struct task_struct *p)
2011{
2012        return 0;
2013}
2014
2015static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2016{
2017}
2018
2019#endif /* CONFIG_SMP */
2020
2021/*
2022 * In order to reduce various lock holder preemption latencies provide an
2023 * interface to see if a vCPU is currently running or not.
2024 *
2025 * This allows us to terminate optimistic spin loops and block, analogous to
2026 * the native optimistic spin heuristic of testing if the lock owner task is
2027 * running or not.
2028 */
2029#ifndef vcpu_is_preempted
2030static inline bool vcpu_is_preempted(int cpu)
2031{
2032        return false;
2033}
2034#endif
2035
2036extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2037extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2038
2039#ifndef TASK_SIZE_OF
2040#define TASK_SIZE_OF(tsk)       TASK_SIZE
2041#endif
2042
2043#ifdef CONFIG_SMP
2044/* Returns effective CPU energy utilization, as seen by the scheduler */
2045unsigned long sched_cpu_util(int cpu, unsigned long max);
2046#endif /* CONFIG_SMP */
2047
2048#ifdef CONFIG_RSEQ
2049
2050/*
2051 * Map the event mask on the user-space ABI enum rseq_cs_flags
2052 * for direct mask checks.
2053 */
2054enum rseq_event_mask_bits {
2055        RSEQ_EVENT_PREEMPT_BIT  = RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT,
2056        RSEQ_EVENT_SIGNAL_BIT   = RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT,
2057        RSEQ_EVENT_MIGRATE_BIT  = RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT,
2058};
2059
2060enum rseq_event_mask {
2061        RSEQ_EVENT_PREEMPT      = (1U << RSEQ_EVENT_PREEMPT_BIT),
2062        RSEQ_EVENT_SIGNAL       = (1U << RSEQ_EVENT_SIGNAL_BIT),
2063        RSEQ_EVENT_MIGRATE      = (1U << RSEQ_EVENT_MIGRATE_BIT),
2064};
2065
2066static inline void rseq_set_notify_resume(struct task_struct *t)
2067{
2068        if (t->rseq)
2069                set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
2070}
2071
2072void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs);
2073
2074static inline void rseq_handle_notify_resume(struct ksignal *ksig,
2075                                             struct pt_regs *regs)
2076{
2077        if (current->rseq)
2078                __rseq_handle_notify_resume(ksig, regs);
2079}
2080
2081static inline void rseq_signal_deliver(struct ksignal *ksig,
2082                                       struct pt_regs *regs)
2083{
2084        preempt_disable();
2085        __set_bit(RSEQ_EVENT_SIGNAL_BIT, &current->rseq_event_mask);
2086        preempt_enable();
2087        rseq_handle_notify_resume(ksig, regs);
2088}
2089
2090/* rseq_preempt() requires preemption to be disabled. */
2091static inline void rseq_preempt(struct task_struct *t)
2092{
2093        __set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask);
2094        rseq_set_notify_resume(t);
2095}
2096
2097/* rseq_migrate() requires preemption to be disabled. */
2098static inline void rseq_migrate(struct task_struct *t)
2099{
2100        __set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask);
2101        rseq_set_notify_resume(t);
2102}
2103
2104/*
2105 * If parent process has a registered restartable sequences area, the
2106 * child inherits. Unregister rseq for a clone with CLONE_VM set.
2107 */
2108static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
2109{
2110        if (clone_flags & CLONE_VM) {
2111                t->rseq = NULL;
2112                t->rseq_sig = 0;
2113                t->rseq_event_mask = 0;
2114        } else {
2115                t->rseq = current->rseq;
2116                t->rseq_sig = current->rseq_sig;
2117                t->rseq_event_mask = current->rseq_event_mask;
2118        }
2119}
2120
2121static inline void rseq_execve(struct task_struct *t)
2122{
2123        t->rseq = NULL;
2124        t->rseq_sig = 0;
2125        t->rseq_event_mask = 0;
2126}
2127
2128#else
2129
2130static inline void rseq_set_notify_resume(struct task_struct *t)
2131{
2132}
2133static inline void rseq_handle_notify_resume(struct ksignal *ksig,
2134                                             struct pt_regs *regs)
2135{
2136}
2137static inline void rseq_signal_deliver(struct ksignal *ksig,
2138                                       struct pt_regs *regs)
2139{
2140}
2141static inline void rseq_preempt(struct task_struct *t)
2142{
2143}
2144static inline void rseq_migrate(struct task_struct *t)
2145{
2146}
2147static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
2148{
2149}
2150static inline void rseq_execve(struct task_struct *t)
2151{
2152}
2153
2154#endif
2155
2156#ifdef CONFIG_DEBUG_RSEQ
2157
2158void rseq_syscall(struct pt_regs *regs);
2159
2160#else
2161
2162static inline void rseq_syscall(struct pt_regs *regs)
2163{
2164}
2165
2166#endif
2167
2168const struct sched_avg *sched_trace_cfs_rq_avg(struct cfs_rq *cfs_rq);
2169char *sched_trace_cfs_rq_path(struct cfs_rq *cfs_rq, char *str, int len);
2170int sched_trace_cfs_rq_cpu(struct cfs_rq *cfs_rq);
2171
2172const struct sched_avg *sched_trace_rq_avg_rt(struct rq *rq);
2173const struct sched_avg *sched_trace_rq_avg_dl(struct rq *rq);
2174const struct sched_avg *sched_trace_rq_avg_irq(struct rq *rq);
2175
2176int sched_trace_rq_cpu(struct rq *rq);
2177int sched_trace_rq_cpu_capacity(struct rq *rq);
2178int sched_trace_rq_nr_running(struct rq *rq);
2179
2180const struct cpumask *sched_trace_rd_span(struct root_domain *rd);
2181
2182#endif
2183