include/linux/sched.h

   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): */
  40 struct audit_context;
  41 struct backing_dev_info;
  42 struct bio_list;
  43 struct blk_plug;
  44 struct bpf_local_storage;
  45 struct bpf_run_ctx;
  46 struct capture_control;
  47 struct cfs_rq;
  48 struct fs_struct;
  49 struct futex_pi_state;
  50 struct io_context;
  51 struct io_uring_task;
  52 struct mempolicy;
  53 struct nameidata;
  54 struct nsproxy;
  55 struct perf_event_context;
  56 struct pid_namespace;
  57 struct pipe_inode_info;
  58 struct rcu_node;
  59 struct reclaim_state;
  60 struct robust_list_head;
  61 struct root_domain;
  62 struct rq;
  63 struct sched_attr;
  64 struct sched_param;
  65 struct seq_file;
  66 struct sighand_struct;
  67 struct signal_struct;
  68 struct task_delay_info;
  69 struct task_group;
  70
  71 /*
  72  * Task state bitmask. NOTE! These bits are also
  73  * encoded in fs/proc/array.c: get_task_state().
  74  *
  75  * We have two separate sets of flags: task->state
  76  * is about runnability, while task->exit_state are
  77  * about the task exiting. Confusing, but this way
  78  * modifying one set can't modify the other one by
  79  * mistake.
  80  */
  81
  82 /* Used in tsk->state: */
  83 #define TASK_RUNNING                    0x0000
  84 #define TASK_INTERRUPTIBLE              0x0001
  85 #define TASK_UNINTERRUPTIBLE            0x0002
  86 #define __TASK_STOPPED                  0x0004
  87 #define __TASK_TRACED                   0x0008
  88 /* Used in tsk->exit_state: */
  89 #define EXIT_DEAD                       0x0010
  90 #define EXIT_ZOMBIE                     0x0020
  91 #define EXIT_TRACE                      (EXIT_ZOMBIE | EXIT_DEAD)
  92 /* Used in tsk->state again: */
  93 #define TASK_PARKED                     0x0040
  94 #define TASK_DEAD                       0x0080
  95 #define TASK_WAKEKILL                   0x0100
  96 #define TASK_WAKING                     0x0200
  97 #define TASK_NOLOAD                     0x0400
  98 #define TASK_NEW                        0x0800
  99 /* RT specific auxilliary flag to mark RT lock waiters */
 100 #define TASK_RTLOCK_WAIT                0x1000
 101 #define TASK_STATE_MAX                  0x2000
 102
 103 /* Convenience macros for the sake of set_current_state: */
 104 #define TASK_KILLABLE                   (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
 105 #define TASK_STOPPED                    (TASK_WAKEKILL | __TASK_STOPPED)
 106 #define TASK_TRACED                     (TASK_WAKEKILL | __TASK_TRACED)
 107
 108 #define TASK_IDLE                       (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
 109
 110 /* Convenience macros for the sake of wake_up(): */
 111 #define TASK_NORMAL                     (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
 112
 113 /* get_task_state(): */
 114 #define TASK_REPORT                     (TASK_RUNNING | TASK_INTERRUPTIBLE | \
 115                                          TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
 116                                          __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
 117                                          TASK_PARKED)
 118
 119 #define task_is_running(task)           (READ_ONCE((task)->__state) == TASK_RUNNING)
 120
 121 #define task_is_traced(task)            ((READ_ONCE(task->__state) & __TASK_TRACED) != 0)
 122
 123 #define task_is_stopped(task)           ((READ_ONCE(task->__state) & __TASK_STOPPED) != 0)
 124
 125 #define task_is_stopped_or_traced(task) ((READ_ONCE(task->__state) & (__TASK_STOPPED | __TASK_TRACED)) != 0)
 126
 127 /*
 128  * Special states are those that do not use the normal wait-loop pattern. See
 129  * the comment with set_special_state().
 130  */
 131 #define is_special_task_state(state)                            \
 132         ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD))
 133
 134 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
 135 # define debug_normal_state_change(state_value)                         \
 136         do {                                                            \
 137                 WARN_ON_ONCE(is_special_task_state(state_value));       \
 138                 current->task_state_change = _THIS_IP_;                 \
 139         } while (0)
 140
 141 # define debug_special_state_change(state_value)                        \
 142         do {                                                            \
 143                 WARN_ON_ONCE(!is_special_task_state(state_value));      \
 144                 current->task_state_change = _THIS_IP_;                 \
 145         } while (0)
 146
 147 # define debug_rtlock_wait_set_state()                                  \
 148         do {                                                             \
 149                 current->saved_state_change = current->task_state_change;\
 150                 current->task_state_change = _THIS_IP_;                  \
 151         } while (0)
 152
 153 # define debug_rtlock_wait_restore_state()                              \
 154         do {                                                             \
 155                 current->task_state_change = current->saved_state_change;\
 156         } while (0)
 157
 158 #else
 159 # define debug_normal_state_change(cond)        do { } while (0)
 160 # define debug_special_state_change(cond)       do { } while (0)
 161 # define debug_rtlock_wait_set_state()          do { } while (0)
 162 # define debug_rtlock_wait_restore_state()      do { } while (0)
 163 #endif
 164
 165 /*
 166  * set_current_state() includes a barrier so that the write of current->state
 167  * is correctly serialised wrt the caller's subsequent test of whether to
 168  * actually sleep:
 169  *
 170  *   for (;;) {
 171  *      set_current_state(TASK_UNINTERRUPTIBLE);
 172  *      if (CONDITION)
 173  *         break;
 174  *
 175  *      schedule();
 176  *   }
 177  *   __set_current_state(TASK_RUNNING);
 178  *
 179  * If the caller does not need such serialisation (because, for instance, the
 180  * CONDITION test and condition change and wakeup are under the same lock) then
 181  * use __set_current_state().
 182  *
 183  * The above is typically ordered against the wakeup, which does:
 184  *
 185  *   CONDITION = 1;
 186  *   wake_up_state(p, TASK_UNINTERRUPTIBLE);
 187  *
 188  * where wake_up_state()/try_to_wake_up() executes a full memory barrier before
 189  * accessing p->state.
 190  *
 191  * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is,
 192  * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
 193  * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
 194  *
 195  * However, with slightly different timing the wakeup TASK_RUNNING store can
 196  * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not
 197  * a problem either because that will result in one extra go around the loop
 198  * and our @cond test will save the day.
 199  *
 200  * Also see the comments of try_to_wake_up().
 201  */
 202 #define __set_current_state(state_value)                                \
 203         do {                                                            \
 204                 debug_normal_state_change((state_value));               \
 205                 WRITE_ONCE(current->__state, (state_value));            \
 206         } while (0)
 207
 208 #define set_current_state(state_value)                                  \
 209         do {                                                            \
 210                 debug_normal_state_change((state_value));               \
 211                 smp_store_mb(current->__state, (state_value));          \
 212         } while (0)
 213
 214 /*
 215  * set_special_state() should be used for those states when the blocking task
 216  * can not use the regular condition based wait-loop. In that case we must
 217  * serialize against wakeups such that any possible in-flight TASK_RUNNING
 218  * stores will not collide with our state change.
 219  */
 220 #define set_special_state(state_value)                                  \
 221         do {                                                            \
 222                 unsigned long flags; /* may shadow */                   \
 223                                                                         \
 224                 raw_spin_lock_irqsave(&current->pi_lock, flags);        \
 225                 debug_special_state_change((state_value));              \
 226                 WRITE_ONCE(current->__state, (state_value));            \
 227                 raw_spin_unlock_irqrestore(&current->pi_lock, flags);   \
 228         } while (0)
 229
 230 /*
 231  * PREEMPT_RT specific variants for "sleeping" spin/rwlocks
 232  *
 233  * RT's spin/rwlock substitutions are state preserving. The state of the
 234  * task when blocking on the lock is saved in task_struct::saved_state and
 235  * restored after the lock has been acquired.  These operations are
 236  * serialized by task_struct::pi_lock against try_to_wake_up(). Any non RT
 237  * lock related wakeups while the task is blocked on the lock are
 238  * redirected to operate on task_struct::saved_state to ensure that these
 239  * are not dropped. On restore task_struct::saved_state is set to
 240  * TASK_RUNNING so any wakeup attempt redirected to saved_state will fail.
 241  *
 242  * The lock operation looks like this:
 243  *
 244  *      current_save_and_set_rtlock_wait_state();
 245  *      for (;;) {
 246  *              if (try_lock())
 247  *                      break;
 248  *              raw_spin_unlock_irq(&lock->wait_lock);
 249  *              schedule_rtlock();
 250  *              raw_spin_lock_irq(&lock->wait_lock);
 251  *              set_current_state(TASK_RTLOCK_WAIT);
 252  *      }
 253  *      current_restore_rtlock_saved_state();
 254  */
 255 #define current_save_and_set_rtlock_wait_state()                        \
 256         do {                                                            \
 257                 lockdep_assert_irqs_disabled();                         \
 258                 raw_spin_lock(&current->pi_lock);                       \
 259                 current->saved_state = current->__state;                \
 260                 debug_rtlock_wait_set_state();                          \
 261                 WRITE_ONCE(current->__state, TASK_RTLOCK_WAIT);         \
 262                 raw_spin_unlock(&current->pi_lock);                     \
 263         } while (0);
 264
 265 #define current_restore_rtlock_saved_state()                            \
 266         do {                                                            \
 267                 lockdep_assert_irqs_disabled();                         \
 268                 raw_spin_lock(&current->pi_lock);                       \
 269                 debug_rtlock_wait_restore_state();                      \
 270                 WRITE_ONCE(current->__state, current->saved_state);     \
 271                 current->saved_state = TASK_RUNNING;                    \
 272                 raw_spin_unlock(&current->pi_lock);                     \
 273         } while (0);
 274
 275 #define get_current_state()     READ_ONCE(current->__state)
 276
 277 /* Task command name length: */
 278 #define TASK_COMM_LEN                   16
 279
 280 extern void scheduler_tick(void);
 281
 282 #define MAX_SCHEDULE_TIMEOUT            LONG_MAX
 283
 284 extern long schedule_timeout(long timeout);
 285 extern long schedule_timeout_interruptible(long timeout);
 286 extern long schedule_timeout_killable(long timeout);
 287 extern long schedule_timeout_uninterruptible(long timeout);
 288 extern long schedule_timeout_idle(long timeout);
 289 asmlinkage void schedule(void);
 290 extern void schedule_preempt_disabled(void);
 291 asmlinkage void preempt_schedule_irq(void);
 292 #ifdef CONFIG_PREEMPT_RT
 293  extern void schedule_rtlock(void);
 294 #endif
 295
 296 extern int __must_check io_schedule_prepare(void);
 297 extern void io_schedule_finish(int token);
 298 extern long io_schedule_timeout(long timeout);
 299 extern void io_schedule(void);
 300
 301 /**
 302  * struct prev_cputime - snapshot of system and user cputime
 303  * @utime: time spent in user mode
 304  * @stime: time spent in system mode
 305  * @lock: protects the above two fields
 306  *
 307  * Stores previous user/system time values such that we can guarantee
 308  * monotonicity.
 309  */
 310 struct prev_cputime {
 311 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 312         u64                             utime;
 313         u64                             stime;
 314         raw_spinlock_t                  lock;
 315 #endif
 316 };
 317
 318 enum vtime_state {
 319         /* Task is sleeping or running in a CPU with VTIME inactive: */
 320         VTIME_INACTIVE = 0,
 321         /* Task is idle */
 322         VTIME_IDLE,
 323         /* Task runs in kernelspace in a CPU with VTIME active: */
 324         VTIME_SYS,
 325         /* Task runs in userspace in a CPU with VTIME active: */
 326         VTIME_USER,
 327         /* Task runs as guests in a CPU with VTIME active: */
 328         VTIME_GUEST,
 329 };
 330
 331 struct vtime {
 332         seqcount_t              seqcount;
 333         unsigned long long      starttime;
 334         enum vtime_state        state;
 335         unsigned int            cpu;
 336         u64                     utime;
 337         u64                     stime;
 338         u64                     gtime;
 339 };
 340
 341 /*
 342  * Utilization clamp constraints.
 343  * @UCLAMP_MIN: Minimum utilization
 344  * @UCLAMP_MAX: Maximum utilization
 345  * @UCLAMP_CNT: Utilization clamp constraints count
 346  */
 347 enum uclamp_id {
 348         UCLAMP_MIN = 0,
 349         UCLAMP_MAX,
 350         UCLAMP_CNT
 351 };
 352
 353 #ifdef CONFIG_SMP
 354 extern struct root_domain def_root_domain;
 355 extern struct mutex sched_domains_mutex;
 356 #endif
 357
 358 struct sched_info {
 359 #ifdef CONFIG_SCHED_INFO
 360         /* Cumulative counters: */
 361
 362         /* # of times we have run on this CPU: */
 363         unsigned long                   pcount;
 364
 365         /* Time spent waiting on a runqueue: */
 366         unsigned long long              run_delay;
 367
 368         /* Timestamps: */
 369
 370         /* When did we last run on a CPU? */
 371         unsigned long long              last_arrival;
 372
 373         /* When were we last queued to run? */
 374         unsigned long long              last_queued;
 375
 376 #endif /* CONFIG_SCHED_INFO */
 377 };
 378
 379 /*
 380  * Integer metrics need fixed point arithmetic, e.g., sched/fair
 381  * has a few: load, load_avg, util_avg, freq, and capacity.
 382  *
 383  * We define a basic fixed point arithmetic range, and then formalize
 384  * all these metrics based on that basic range.
 385  */
 386 # define SCHED_FIXEDPOINT_SHIFT         10
 387 # define SCHED_FIXEDPOINT_SCALE         (1L << SCHED_FIXEDPOINT_SHIFT)
 388
 389 /* Increase resolution of cpu_capacity calculations */
 390 # define SCHED_CAPACITY_SHIFT           SCHED_FIXEDPOINT_SHIFT
 391 # define SCHED_CAPACITY_SCALE           (1L << SCHED_CAPACITY_SHIFT)
 392
 393 struct load_weight {
 394         unsigned long                   weight;
 395         u32                             inv_weight;
 396 };
 397
 398 /**
 399  * struct util_est - Estimation utilization of FAIR tasks
 400  * @enqueued: instantaneous estimated utilization of a task/cpu
 401  * @ewma:     the Exponential Weighted Moving Average (EWMA)
 402  *            utilization of a task
 403  *
 404  * Support data structure to track an Exponential Weighted Moving Average
 405  * (EWMA) of a FAIR task's utilization. New samples are added to the moving
 406  * average each time a task completes an activation. Sample's weight is chosen
 407  * so that the EWMA will be relatively insensitive to transient changes to the
 408  * task's workload.
 409  *
 410  * The enqueued attribute has a slightly different meaning for tasks and cpus:
 411  * - task:   the task's util_avg at last task dequeue time
 412  * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU
 413  * Thus, the util_est.enqueued of a task represents the contribution on the
 414  * estimated utilization of the CPU where that task is currently enqueued.
 415  *
 416  * Only for tasks we track a moving average of the past instantaneous
 417  * estimated utilization. This allows to absorb sporadic drops in utilization
 418  * of an otherwise almost periodic task.
 419  *
 420  * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg
 421  * updates. When a task is dequeued, its util_est should not be updated if its
 422  * util_avg has not been updated in the meantime.
 423  * This information is mapped into the MSB bit of util_est.enqueued at dequeue
 424  * time. Since max value of util_est.enqueued for a task is 1024 (PELT util_avg
 425  * for a task) it is safe to use MSB.
 426  */
 427 struct util_est {
 428         unsigned int                    enqueued;
 429         unsigned int                    ewma;
 430 #define UTIL_EST_WEIGHT_SHIFT           2
 431 #define UTIL_AVG_UNCHANGED              0x80000000
 432 } __attribute__((__aligned__(sizeof(u64))));
 433
 434 /*
 435  * The load/runnable/util_avg accumulates an infinite geometric series
 436  * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c).
 437  *
 438  * [load_avg definition]
 439  *
 440  *   load_avg = runnable% * scale_load_down(load)
 441  *
 442  * [runnable_avg definition]
 443  *
 444  *   runnable_avg = runnable% * SCHED_CAPACITY_SCALE
 445  *
 446  * [util_avg definition]
 447  *
 448  *   util_avg = running% * SCHED_CAPACITY_SCALE
 449  *
 450  * where runnable% is the time ratio that a sched_entity is runnable and
 451  * running% the time ratio that a sched_entity is running.
 452  *
 453  * For cfs_rq, they are the aggregated values of all runnable and blocked
 454  * sched_entities.
 455  *
 456  * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU
 457  * capacity scaling. The scaling is done through the rq_clock_pelt that is used
 458  * for computing those signals (see update_rq_clock_pelt())
 459  *
 460  * N.B., the above ratios (runnable% and running%) themselves are in the
 461  * range of [0, 1]. To do fixed point arithmetics, we therefore scale them
 462  * to as large a range as necessary. This is for example reflected by
 463  * util_avg's SCHED_CAPACITY_SCALE.
 464  *
 465  * [Overflow issue]
 466  *
 467  * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
 468  * with the highest load (=88761), always runnable on a single cfs_rq,
 469  * and should not overflow as the number already hits PID_MAX_LIMIT.
 470  *
 471  * For all other cases (including 32-bit kernels), struct load_weight's
 472  * weight will overflow first before we do, because:
 473  *
 474  *    Max(load_avg) <= Max(load.weight)
 475  *
 476  * Then it is the load_weight's responsibility to consider overflow
 477  * issues.
 478  */
 479 struct sched_avg {
 480         u64                             last_update_time;
 481         u64                             load_sum;
 482         u64                             runnable_sum;
 483         u32                             util_sum;
 484         u32                             period_contrib;
 485         unsigned long                   load_avg;
 486         unsigned long                   runnable_avg;
 487         unsigned long                   util_avg;
 488         struct util_est                 util_est;
 489 } ____cacheline_aligned;
 490
 491 struct sched_statistics {
 492 #ifdef CONFIG_SCHEDSTATS
 493         u64                             wait_start;
 494         u64                             wait_max;
 495         u64                             wait_count;
 496         u64                             wait_sum;
 497         u64                             iowait_count;
 498         u64                             iowait_sum;
 499
 500         u64                             sleep_start;
 501         u64                             sleep_max;
 502         s64                             sum_sleep_runtime;
 503
 504         u64                             block_start;
 505         u64                             block_max;
 506         s64                             sum_block_runtime;
 507
 508         u64                             exec_max;
 509         u64                             slice_max;
 510
 511         u64                             nr_migrations_cold;
 512         u64                             nr_failed_migrations_affine;
 513         u64                             nr_failed_migrations_running;
 514         u64                             nr_failed_migrations_hot;
 515         u64                             nr_forced_migrations;
 516
 517         u64                             nr_wakeups;
 518         u64                             nr_wakeups_sync;
 519         u64                             nr_wakeups_migrate;
 520         u64                             nr_wakeups_local;
 521         u64                             nr_wakeups_remote;
 522         u64                             nr_wakeups_affine;
 523         u64                             nr_wakeups_affine_attempts;
 524         u64                             nr_wakeups_passive;
 525         u64                             nr_wakeups_idle;
 526
 527 #ifdef CONFIG_SCHED_CORE
 528         u64                             core_forceidle_sum;
 529 #endif
 530 #endif /* CONFIG_SCHEDSTATS */
 531 } ____cacheline_aligned;
 532
 533 struct sched_entity {
 534         /* For load-balancing: */
 535         struct load_weight              load;
 536         struct rb_node                  run_node;
 537         struct list_head                group_node;
 538         unsigned int                    on_rq;
 539
 540         u64                             exec_start;
 541         u64                             sum_exec_runtime;
 542         u64                             vruntime;
 543         u64                             prev_sum_exec_runtime;
 544
 545         u64                             nr_migrations;
 546
 547 #ifdef CONFIG_FAIR_GROUP_SCHED
 548         int                             depth;
 549         struct sched_entity             *parent;
 550         /* rq on which this entity is (to be) queued: */
 551         struct cfs_rq                   *cfs_rq;
 552         /* rq "owned" by this entity/group: */
 553         struct cfs_rq                   *my_q;
 554         /* cached value of my_q->h_nr_running */
 555         unsigned long                   runnable_weight;
 556 #endif
 557
 558 #ifdef CONFIG_SMP
 559         /*
 560          * Per entity load average tracking.
 561          *
 562          * Put into separate cache line so it does not
 563          * collide with read-mostly values above.
 564          */
 565         struct sched_avg                avg;
 566 #endif
 567 };
 568
 569 struct sched_rt_entity {
 570         struct list_head                run_list;
 571         unsigned long                   timeout;
 572         unsigned long                   watchdog_stamp;
 573         unsigned int                    time_slice;
 574         unsigned short                  on_rq;
 575         unsigned short                  on_list;
 576
 577         struct sched_rt_entity          *back;
 578 #ifdef CONFIG_RT_GROUP_SCHED
 579         struct sched_rt_entity          *parent;
 580         /* rq on which this entity is (to be) queued: */
 581         struct rt_rq                    *rt_rq;
 582         /* rq "owned" by this entity/group: */
 583         struct rt_rq                    *my_q;
 584 #endif
 585 } __randomize_layout;
 586
 587 struct sched_dl_entity {
 588         struct rb_node                  rb_node;
 589
 590         /*
 591          * Original scheduling parameters. Copied here from sched_attr
 592          * during sched_setattr(), they will remain the same until
 593          * the next sched_setattr().
 594          */
 595         u64                             dl_runtime;     /* Maximum runtime for each instance    */
 596         u64                             dl_deadline;    /* Relative deadline of each instance   */
 597         u64                             dl_period;      /* Separation of two instances (period) */
 598         u64                             dl_bw;          /* dl_runtime / dl_period               */
 599         u64                             dl_density;     /* dl_runtime / dl_deadline             */
 600
 601         /*
 602          * Actual scheduling parameters. Initialized with the values above,
 603          * they are continuously updated during task execution. Note that
 604          * the remaining runtime could be < 0 in case we are in overrun.
 605          */
 606         s64                             runtime;        /* Remaining runtime for this instance  */
 607         u64                             deadline;       /* Absolute deadline for this instance  */
 608         unsigned int                    flags;          /* Specifying the scheduler behaviour   */
 609
 610         /*
 611          * Some bool flags:
 612          *
 613          * @dl_throttled tells if we exhausted the runtime. If so, the
 614          * task has to wait for a replenishment to be performed at the
 615          * next firing of dl_timer.
 616          *
 617          * @dl_boosted tells if we are boosted due to DI. If so we are
 618          * outside bandwidth enforcement mechanism (but only until we
 619          * exit the critical section);
 620          *
 621          * @dl_yielded tells if task gave up the CPU before consuming
 622          * all its available runtime during the last job.
 623          *
 624          * @dl_non_contending tells if the task is inactive while still
 625          * contributing to the active utilization. In other words, it
 626          * indicates if the inactive timer has been armed and its handler
 627          * has not been executed yet. This flag is useful to avoid race
 628          * conditions between the inactive timer handler and the wakeup
 629          * code.
 630          *
 631          * @dl_overrun tells if the task asked to be informed about runtime
 632          * overruns.
 633          */
 634         unsigned int                    dl_throttled      : 1;
 635         unsigned int                    dl_yielded        : 1;
 636         unsigned int                    dl_non_contending : 1;
 637         unsigned int                    dl_overrun        : 1;
 638
 639         /*
 640          * Bandwidth enforcement timer. Each -deadline task has its
 641          * own bandwidth to be enforced, thus we need one timer per task.
 642          */
 643         struct hrtimer                  dl_timer;
 644
 645         /*
 646          * Inactive timer, responsible for decreasing the active utilization
 647          * at the "0-lag time". When a -deadline task blocks, it contributes
 648          * to GRUB's active utilization until the "0-lag time", hence a
 649          * timer is needed to decrease the active utilization at the correct
 650          * time.
 651          */
 652         struct hrtimer inactive_timer;
 653
 654 #ifdef CONFIG_RT_MUTEXES
 655         /*
 656          * Priority Inheritance. When a DEADLINE scheduling entity is boosted
 657          * pi_se points to the donor, otherwise points to the dl_se it belongs
 658          * to (the original one/itself).
 659          */
 660         struct sched_dl_entity *pi_se;
 661 #endif
 662 };
 663
 664 #ifdef CONFIG_UCLAMP_TASK
 665 /* Number of utilization clamp buckets (shorter alias) */
 666 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT
 667
 668 /*
 669  * Utilization clamp for a scheduling entity
 670  * @value:              clamp value "assigned" to a se
 671  * @bucket_id:          bucket index corresponding to the "assigned" value
 672  * @active:             the se is currently refcounted in a rq's bucket
 673  * @user_defined:       the requested clamp value comes from user-space
 674  *
 675  * The bucket_id is the index of the clamp bucket matching the clamp value
 676  * which is pre-computed and stored to avoid expensive integer divisions from
 677  * the fast path.
 678  *
 679  * The active bit is set whenever a task has got an "effective" value assigned,
 680  * which can be different from the clamp value "requested" from user-space.
 681  * This allows to know a task is refcounted in the rq's bucket corresponding
 682  * to the "effective" bucket_id.
 683  *
 684  * The user_defined bit is set whenever a task has got a task-specific clamp
 685  * value requested from userspace, i.e. the system defaults apply to this task
 686  * just as a restriction. This allows to relax default clamps when a less
 687  * restrictive task-specific value has been requested, thus allowing to
 688  * implement a "nice" semantic. For example, a task running with a 20%
 689  * default boost can still drop its own boosting to 0%.
 690  */
 691 struct uclamp_se {
 692         unsigned int value              : bits_per(SCHED_CAPACITY_SCALE);
 693         unsigned int bucket_id          : bits_per(UCLAMP_BUCKETS);
 694         unsigned int active             : 1;
 695         unsigned int user_defined       : 1;
 696 };
 697 #endif /* CONFIG_UCLAMP_TASK */
 698
 699 union rcu_special {
 700         struct {
 701                 u8                      blocked;
 702                 u8                      need_qs;
 703                 u8                      exp_hint; /* Hint for performance. */
 704                 u8                      need_mb; /* Readers need smp_mb(). */
 705         } b; /* Bits. */
 706         u32 s; /* Set of bits. */
 707 };
 708
 709 enum perf_event_task_context {
 710         perf_invalid_context = -1,
 711         perf_hw_context = 0,
 712         perf_sw_context,
 713         perf_nr_task_contexts,
 714 };
 715
 716 struct wake_q_node {
 717         struct wake_q_node *next;
 718 };
 719
 720 struct kmap_ctrl {
 721 #ifdef CONFIG_KMAP_LOCAL
 722         int                             idx;
 723         pte_t                           pteval[KM_MAX_IDX];
 724 #endif
 725 };
 726
 727 struct task_struct {
 728 #ifdef CONFIG_THREAD_INFO_IN_TASK
 729         /*
 730          * For reasons of header soup (see current_thread_info()), this
 731          * must be the first element of task_struct.
 732          */
 733         struct thread_info              thread_info;
 734 #endif
 735         unsigned int                    __state;
 736
 737 #ifdef CONFIG_PREEMPT_RT
 738         /* saved state for "spinlock sleepers" */
 739         unsigned int                    saved_state;
 740 #endif
 741
 742         /*
 743          * This begins the randomizable portion of task_struct. Only
 744          * scheduling-critical items should be added above here.
 745          */
 746         randomized_struct_fields_start
 747
 748         void                            *stack;
 749         refcount_t                      usage;
 750         /* Per task flags (PF_*), defined further below: */
 751         unsigned int                    flags;
 752         unsigned int                    ptrace;
 753
 754 #ifdef CONFIG_SMP
 755         int                             on_cpu;
 756         struct __call_single_node       wake_entry;
 757         unsigned int                    wakee_flips;
 758         unsigned long                   wakee_flip_decay_ts;
 759         struct task_struct              *last_wakee;
 760
 761         /*
 762          * recent_used_cpu is initially set as the last CPU used by a task
 763          * that wakes affine another task. Waker/wakee relationships can
 764          * push tasks around a CPU where each wakeup moves to the next one.
 765          * Tracking a recently used CPU allows a quick search for a recently
 766          * used CPU that may be idle.
 767          */
 768         int                             recent_used_cpu;
 769         int                             wake_cpu;
 770 #endif
 771         int                             on_rq;
 772
 773         int                             prio;
 774         int                             static_prio;
 775         int                             normal_prio;
 776         unsigned int                    rt_priority;
 777
 778         struct sched_entity             se;
 779         struct sched_rt_entity          rt;
 780         struct sched_dl_entity          dl;
 781         const struct sched_class        *sched_class;
 782
 783 #ifdef CONFIG_SCHED_CORE
 784         struct rb_node                  core_node;
 785         unsigned long                   core_cookie;
 786         unsigned int                    core_occupation;
 787 #endif
 788
 789 #ifdef CONFIG_CGROUP_SCHED
 790         struct task_group               *sched_task_group;
 791 #endif
 792
 793 #ifdef CONFIG_UCLAMP_TASK
 794         /*
 795          * Clamp values requested for a scheduling entity.
 796          * Must be updated with task_rq_lock() held.
 797          */
 798         struct uclamp_se                uclamp_req[UCLAMP_CNT];
 799         /*
 800          * Effective clamp values used for a scheduling entity.
 801          * Must be updated with task_rq_lock() held.
 802          */
 803         struct uclamp_se                uclamp[UCLAMP_CNT];
 804 #endif
 805
 806         struct sched_statistics         stats;
 807
 808 #ifdef CONFIG_PREEMPT_NOTIFIERS
 809         /* List of struct preempt_notifier: */
 810         struct hlist_head               preempt_notifiers;
 811 #endif
 812
 813 #ifdef CONFIG_BLK_DEV_IO_TRACE
 814         unsigned int                    btrace_seq;
 815 #endif
 816
 817         unsigned int                    policy;
 818         int                             nr_cpus_allowed;
 819         const cpumask_t                 *cpus_ptr;
 820         cpumask_t                       *user_cpus_ptr;
 821         cpumask_t                       cpus_mask;
 822         void                            *migration_pending;
 823 #ifdef CONFIG_SMP
 824         unsigned short                  migration_disabled;
 825 #endif
 826         unsigned short                  migration_flags;
 827
 828 #ifdef CONFIG_PREEMPT_RCU
 829         int                             rcu_read_lock_nesting;
 830         union rcu_special               rcu_read_unlock_special;
 831         struct list_head                rcu_node_entry;
 832         struct rcu_node                 *rcu_blocked_node;
 833 #endif /* #ifdef CONFIG_PREEMPT_RCU */
 834
 835 #ifdef CONFIG_TASKS_RCU
 836         unsigned long                   rcu_tasks_nvcsw;
 837         u8                              rcu_tasks_holdout;
 838         u8                              rcu_tasks_idx;
 839         int                             rcu_tasks_idle_cpu;
 840         struct list_head                rcu_tasks_holdout_list;
 841 #endif /* #ifdef CONFIG_TASKS_RCU */
 842
 843 #ifdef CONFIG_TASKS_TRACE_RCU
 844         int                             trc_reader_nesting;
 845         int                             trc_ipi_to_cpu;
 846         union rcu_special               trc_reader_special;
 847         bool                            trc_reader_checked;
 848         struct list_head                trc_holdout_list;
 849 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
 850
 851         struct sched_info               sched_info;
 852
 853         struct list_head                tasks;
 854 #ifdef CONFIG_SMP
 855         struct plist_node               pushable_tasks;
 856         struct rb_node                  pushable_dl_tasks;
 857 #endif
 858
 859         struct mm_struct                *mm;
 860         struct mm_struct                *active_mm;
 861
 862         /* Per-thread vma caching: */
 863         struct vmacache                 vmacache;
 864
 865 #ifdef SPLIT_RSS_COUNTING
 866         struct task_rss_stat            rss_stat;
 867 #endif
 868         int                             exit_state;
 869         int                             exit_code;
 870         int                             exit_signal;
 871         /* The signal sent when the parent dies: */
 872         int                             pdeath_signal;
 873         /* JOBCTL_*, siglock protected: */
 874         unsigned long                   jobctl;
 875
 876         /* Used for emulating ABI behavior of previous Linux versions: */
 877         unsigned int                    personality;
 878
 879         /* Scheduler bits, serialized by scheduler locks: */
 880         unsigned                        sched_reset_on_fork:1;
 881         unsigned                        sched_contributes_to_load:1;
 882         unsigned                        sched_migrated:1;
 883 #ifdef CONFIG_PSI
 884         unsigned                        sched_psi_wake_requeue:1;
 885 #endif
 886
 887         /* Force alignment to the next boundary: */
 888         unsigned                        :0;
 889
 890         /* Unserialized, strictly 'current' */
 891
 892         /*
 893          * This field must not be in the scheduler word above due to wakelist
 894          * queueing no longer being serialized by p->on_cpu. However:
 895          *
 896          * p->XXX = X;                  ttwu()
 897          * schedule()                     if (p->on_rq && ..) // false
 898          *   smp_mb__after_spinlock();    if (smp_load_acquire(&p->on_cpu) && //true
 899          *   deactivate_task()                ttwu_queue_wakelist())
 900          *     p->on_rq = 0;                    p->sched_remote_wakeup = Y;
 901          *
 902          * guarantees all stores of 'current' are visible before
 903          * ->sched_remote_wakeup gets used, so it can be in this word.
 904          */
 905         unsigned                        sched_remote_wakeup:1;
 906
 907         /* Bit to tell LSMs we're in execve(): */
 908         unsigned                        in_execve:1;
 909         unsigned                        in_iowait:1;
 910 #ifndef TIF_RESTORE_SIGMASK
 911         unsigned                        restore_sigmask:1;
 912 #endif
 913 #ifdef CONFIG_MEMCG
 914         unsigned                        in_user_fault:1;
 915 #endif
 916 #ifdef CONFIG_COMPAT_BRK
 917         unsigned                        brk_randomized:1;
 918 #endif
 919 #ifdef CONFIG_CGROUPS
 920         /* disallow userland-initiated cgroup migration */
 921         unsigned                        no_cgroup_migration:1;
 922         /* task is frozen/stopped (used by the cgroup freezer) */
 923         unsigned                        frozen:1;
 924 #endif
 925 #ifdef CONFIG_BLK_CGROUP
 926         unsigned                        use_memdelay:1;
 927 #endif
 928 #ifdef CONFIG_PSI
 929         /* Stalled due to lack of memory */
 930         unsigned                        in_memstall:1;
 931 #endif
 932 #ifdef CONFIG_PAGE_OWNER
 933         /* Used by page_owner=on to detect recursion in page tracking. */
 934         unsigned                        in_page_owner:1;
 935 #endif
 936 #ifdef CONFIG_EVENTFD
 937         /* Recursion prevention for eventfd_signal() */
 938         unsigned                        in_eventfd_signal:1;
 939 #endif
 940
 941         unsigned long                   atomic_flags; /* Flags requiring atomic access. */
 942
 943         struct restart_block            restart_block;
 944
 945         pid_t                           pid;
 946         pid_t                           tgid;
 947
 948 #ifdef CONFIG_STACKPROTECTOR
 949         /* Canary value for the -fstack-protector GCC feature: */
 950         unsigned long                   stack_canary;
 951 #endif
 952         /*
 953          * Pointers to the (original) parent process, youngest child, younger sibling,
 954          * older sibling, respectively.  (p->father can be replaced with
 955          * p->real_parent->pid)
 956          */
 957
 958         /* Real parent process: */
 959         struct task_struct __rcu        *real_parent;
 960
 961         /* Recipient of SIGCHLD, wait4() reports: */
 962         struct task_struct __rcu        *parent;
 963
 964         /*
 965          * Children/sibling form the list of natural children:
 966          */
 967         struct list_head                children;
 968         struct list_head                sibling;
 969         struct task_struct              *group_leader;
 970
 971         /*
 972          * 'ptraced' is the list of tasks this task is using ptrace() on.
 973          *
 974          * This includes both natural children and PTRACE_ATTACH targets.
 975          * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
 976          */
 977         struct list_head                ptraced;
 978         struct list_head                ptrace_entry;
 979
 980         /* PID/PID hash table linkage. */
 981         struct pid                      *thread_pid;
 982         struct hlist_node               pid_links[PIDTYPE_MAX];
 983         struct list_head                thread_group;
 984         struct list_head                thread_node;
 985
 986         struct completion               *vfork_done;
 987
 988         /* CLONE_CHILD_SETTID: */
 989         int __user                      *set_child_tid;
 990
 991         /* CLONE_CHILD_CLEARTID: */
 992         int __user                      *clear_child_tid;
 993
 994         /* PF_IO_WORKER */
 995         void                            *pf_io_worker;
 996
 997         u64                             utime;
 998         u64                             stime;
 999 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
1000         u64                             utimescaled;
1001         u64                             stimescaled;
1002 #endif
1003         u64                             gtime;
1004         struct prev_cputime             prev_cputime;
1005 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1006         struct vtime                    vtime;
1007 #endif
1008
1009 #ifdef CONFIG_NO_HZ_FULL
1010         atomic_t                        tick_dep_mask;
1011 #endif
1012         /* Context switch counts: */
1013         unsigned long                   nvcsw;
1014         unsigned long                   nivcsw;
1015
1016         /* Monotonic time in nsecs: */
1017         u64                             start_time;
1018
1019         /* Boot based time in nsecs: */
1020         u64                             start_boottime;
1021
1022         /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
1023         unsigned long                   min_flt;
1024         unsigned long                   maj_flt;
1025
1026         /* Empty if CONFIG_POSIX_CPUTIMERS=n */
1027         struct posix_cputimers          posix_cputimers;
1028
1029 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK
1030         struct posix_cputimers_work     posix_cputimers_work;
1031 #endif
1032
1033         /* Process credentials: */
1034
1035         /* Tracer's credentials at attach: */
1036         const struct cred __rcu         *ptracer_cred;
1037
1038         /* Objective and real subjective task credentials (COW): */
1039         const struct cred __rcu         *real_cred;
1040
1041         /* Effective (overridable) subjective task credentials (COW): */
1042         const struct cred __rcu         *cred;
1043
1044 #ifdef CONFIG_KEYS
1045         /* Cached requested key. */
1046         struct key                      *cached_requested_key;
1047 #endif
1048
1049         /*
1050          * executable name, excluding path.
1051          *
1052          * - normally initialized setup_new_exec()
1053          * - access it with [gs]et_task_comm()
1054          * - lock it with task_lock()
1055          */
1056         char                            comm[TASK_COMM_LEN];
1057
1058         struct nameidata                *nameidata;
1059
1060 #ifdef CONFIG_SYSVIPC
1061         struct sysv_sem                 sysvsem;
1062         struct sysv_shm                 sysvshm;
1063 #endif
1064 #ifdef CONFIG_DETECT_HUNG_TASK
1065         unsigned long                   last_switch_count;
1066         unsigned long                   last_switch_time;
1067 #endif
1068         /* Filesystem information: */
1069         struct fs_struct                *fs;
1070
1071         /* Open file information: */
1072         struct files_struct             *files;
1073
1074 #ifdef CONFIG_IO_URING
1075         struct io_uring_task            *io_uring;
1076 #endif
1077
1078         /* Namespaces: */
1079         struct nsproxy                  *nsproxy;
1080
1081         /* Signal handlers: */
1082         struct signal_struct            *signal;
1083         struct sighand_struct __rcu             *sighand;
1084         sigset_t                        blocked;
1085         sigset_t                        real_blocked;
1086         /* Restored if set_restore_sigmask() was used: */
1087         sigset_t                        saved_sigmask;
1088         struct sigpending               pending;
1089         unsigned long                   sas_ss_sp;
1090         size_t                          sas_ss_size;
1091         unsigned int                    sas_ss_flags;
1092
1093         struct callback_head            *task_works;
1094
1095 #ifdef CONFIG_AUDIT
1096 #ifdef CONFIG_AUDITSYSCALL
1097         struct audit_context            *audit_context;
1098 #endif
1099         kuid_t                          loginuid;
1100         unsigned int                    sessionid;
1101 #endif
1102         struct seccomp                  seccomp;
1103         struct syscall_user_dispatch    syscall_dispatch;
1104
1105         /* Thread group tracking: */
1106         u64                             parent_exec_id;
1107         u64                             self_exec_id;
1108
1109         /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
1110         spinlock_t                      alloc_lock;
1111
1112         /* Protection of the PI data structures: */
1113         raw_spinlock_t                  pi_lock;
1114
1115         struct wake_q_node              wake_q;
1116
1117 #ifdef CONFIG_RT_MUTEXES
1118         /* PI waiters blocked on a rt_mutex held by this task: */
1119         struct rb_root_cached           pi_waiters;
1120         /* Updated under owner's pi_lock and rq lock */
1121         struct task_struct              *pi_top_task;
1122         /* Deadlock detection and priority inheritance handling: */
1123         struct rt_mutex_waiter          *pi_blocked_on;
1124 #endif
1125
1126 #ifdef CONFIG_DEBUG_MUTEXES
1127         /* Mutex deadlock detection: */
1128         struct mutex_waiter             *blocked_on;
1129 #endif
1130
1131 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1132         int                             non_block_count;
1133 #endif
1134
1135 #ifdef CONFIG_TRACE_IRQFLAGS
1136         struct irqtrace_events          irqtrace;
1137         unsigned int                    hardirq_threaded;
1138         u64                             hardirq_chain_key;
1139         int                             softirqs_enabled;
1140         int                             softirq_context;
1141         int                             irq_config;
1142 #endif
1143 #ifdef CONFIG_PREEMPT_RT
1144         int                             softirq_disable_cnt;
1145 #endif
1146
1147 #ifdef CONFIG_LOCKDEP
1148 # define MAX_LOCK_DEPTH                 48UL
1149         u64                             curr_chain_key;
1150         int                             lockdep_depth;
1151         unsigned int                    lockdep_recursion;
1152         struct held_lock                held_locks[MAX_LOCK_DEPTH];
1153 #endif
1154
1155 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP)
1156         unsigned int                    in_ubsan;
1157 #endif
1158
1159         /* Journalling filesystem info: */
1160         void                            *journal_info;
1161
1162         /* Stacked block device info: */
1163         struct bio_list                 *bio_list;
1164
1165         /* Stack plugging: */
1166         struct blk_plug                 *plug;
1167
1168         /* VM state: */
1169         struct reclaim_state            *reclaim_state;
1170
1171         struct backing_dev_info         *backing_dev_info;
1172
1173         struct io_context               *io_context;
1174
1175 #ifdef CONFIG_COMPACTION
1176         struct capture_control          *capture_control;
1177 #endif
1178         /* Ptrace state: */
1179         unsigned long                   ptrace_message;
1180         kernel_siginfo_t                *last_siginfo;
1181
1182         struct task_io_accounting       ioac;
1183 #ifdef CONFIG_PSI
1184         /* Pressure stall state */
1185         unsigned int                    psi_flags;
1186 #endif
1187 #ifdef CONFIG_TASK_XACCT
1188         /* Accumulated RSS usage: */
1189         u64                             acct_rss_mem1;
1190         /* Accumulated virtual memory usage: */
1191         u64                             acct_vm_mem1;
1192         /* stime + utime since last update: */
1193         u64                             acct_timexpd;
1194 #endif
1195 #ifdef CONFIG_CPUSETS
1196         /* Protected by ->alloc_lock: */
1197         nodemask_t                      mems_allowed;
1198         /* Sequence number to catch updates: */
1199         seqcount_spinlock_t             mems_allowed_seq;
1200         int                             cpuset_mem_spread_rotor;
1201         int                             cpuset_slab_spread_rotor;
1202 #endif
1203 #ifdef CONFIG_CGROUPS
1204         /* Control Group info protected by css_set_lock: */
1205         struct css_set __rcu            *cgroups;
1206         /* cg_list protected by css_set_lock and tsk->alloc_lock: */
1207         struct list_head                cg_list;
1208 #endif
1209 #ifdef CONFIG_X86_CPU_RESCTRL
1210         u32                             closid;
1211         u32                             rmid;
1212 #endif
1213 #ifdef CONFIG_FUTEX
1214         struct robust_list_head __user  *robust_list;
1215 #ifdef CONFIG_COMPAT
1216         struct compat_robust_list_head __user *compat_robust_list;
1217 #endif
1218         struct list_head                pi_state_list;
1219         struct futex_pi_state           *pi_state_cache;
1220         struct mutex                    futex_exit_mutex;
1221         unsigned int                    futex_state;
1222 #endif
1223 #ifdef CONFIG_PERF_EVENTS
1224         struct perf_event_context       *perf_event_ctxp[perf_nr_task_contexts];
1225         struct mutex                    perf_event_mutex;
1226         struct list_head                perf_event_list;
1227 #endif
1228 #ifdef CONFIG_DEBUG_PREEMPT
1229         unsigned long                   preempt_disable_ip;
1230 #endif
1231 #ifdef CONFIG_NUMA
1232         /* Protected by alloc_lock: */
1233         struct mempolicy                *mempolicy;
1234         short                           il_prev;
1235         short                           pref_node_fork;
1236 #endif
1237 #ifdef CONFIG_NUMA_BALANCING
1238         int                             numa_scan_seq;
1239         unsigned int                    numa_scan_period;
1240         unsigned int                    numa_scan_period_max;
1241         int                             numa_preferred_nid;
1242         unsigned long                   numa_migrate_retry;
1243         /* Migration stamp: */
1244         u64                             node_stamp;
1245         u64                             last_task_numa_placement;
1246         u64                             last_sum_exec_runtime;
1247         struct callback_head            numa_work;
1248
1249         /*
1250          * This pointer is only modified for current in syscall and
1251          * pagefault context (and for tasks being destroyed), so it can be read
1252          * from any of the following contexts:
1253          *  - RCU read-side critical section
1254          *  - current->numa_group from everywhere
1255          *  - task's runqueue locked, task not running
1256          */
1257         struct numa_group __rcu         *numa_group;
1258
1259         /*
1260          * numa_faults is an array split into four regions:
1261          * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1262          * in this precise order.
1263          *
1264          * faults_memory: Exponential decaying average of faults on a per-node
1265          * basis. Scheduling placement decisions are made based on these
1266          * counts. The values remain static for the duration of a PTE scan.
1267          * faults_cpu: Track the nodes the process was running on when a NUMA
1268          * hinting fault was incurred.
1269          * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1270          * during the current scan window. When the scan completes, the counts
1271          * in faults_memory and faults_cpu decay and these values are copied.
1272          */
1273         unsigned long                   *numa_faults;
1274         unsigned long                   total_numa_faults;
1275
1276         /*
1277          * numa_faults_locality tracks if faults recorded during the last
1278          * scan window were remote/local or failed to migrate. The task scan
1279          * period is adapted based on the locality of the faults with different
1280          * weights depending on whether they were shared or private faults
1281          */
1282         unsigned long                   numa_faults_locality[3];
1283
1284         unsigned long                   numa_pages_migrated;
1285 #endif /* CONFIG_NUMA_BALANCING */
1286
1287 #ifdef CONFIG_RSEQ
1288         struct rseq __user *rseq;
1289         u32 rseq_sig;
1290         /*
1291          * RmW on rseq_event_mask must be performed atomically
1292          * with respect to preemption.
1293          */
1294         unsigned long rseq_event_mask;
1295 #endif
1296
1297         struct tlbflush_unmap_batch     tlb_ubc;
1298
1299         union {
1300                 refcount_t              rcu_users;
1301                 struct rcu_head         rcu;
1302         };
1303
1304         /* Cache last used pipe for splice(): */
1305         struct pipe_inode_info          *splice_pipe;
1306
1307         struct page_frag                task_frag;
1308
1309 #ifdef CONFIG_TASK_DELAY_ACCT
1310         struct task_delay_info          *delays;
1311 #endif
1312
1313 #ifdef CONFIG_FAULT_INJECTION
1314         int                             make_it_fail;
1315         unsigned int                    fail_nth;
1316 #endif
1317         /*
1318          * When (nr_dirtied >= nr_dirtied_pause), it's time to call
1319          * balance_dirty_pages() for a dirty throttling pause:
1320          */
1321         int                             nr_dirtied;
1322         int                             nr_dirtied_pause;
1323         /* Start of a write-and-pause period: */
1324         unsigned long                   dirty_paused_when;
1325
1326 #ifdef CONFIG_LATENCYTOP
1327         int                             latency_record_count;
1328         struct latency_record           latency_record[LT_SAVECOUNT];
1329 #endif
1330         /*
1331          * Time slack values; these are used to round up poll() and
1332          * select() etc timeout values. These are in nanoseconds.
1333          */
1334         u64                             timer_slack_ns;
1335         u64                             default_timer_slack_ns;
1336
1337 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
1338         unsigned int                    kasan_depth;
1339 #endif
1340
1341 #ifdef CONFIG_KCSAN
1342         struct kcsan_ctx                kcsan_ctx;
1343 #ifdef CONFIG_TRACE_IRQFLAGS
1344         struct irqtrace_events          kcsan_save_irqtrace;
1345 #endif
1346 #ifdef CONFIG_KCSAN_WEAK_MEMORY
1347         int                             kcsan_stack_depth;
1348 #endif
1349 #endif
1350
1351 #if IS_ENABLED(CONFIG_KUNIT)
1352         struct kunit                    *kunit_test;
1353 #endif
1354
1355 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1356         /* Index of current stored address in ret_stack: */
1357         int                             curr_ret_stack;
1358         int                             curr_ret_depth;
1359
1360         /* Stack of return addresses for return function tracing: */
1361         struct ftrace_ret_stack         *ret_stack;
1362
1363         /* Timestamp for last schedule: */
1364         unsigned long long              ftrace_timestamp;
1365
1366         /*
1367          * Number of functions that haven't been traced
1368          * because of depth overrun:
1369          */
1370         atomic_t                        trace_overrun;
1371
1372         /* Pause tracing: */
1373         atomic_t                        tracing_graph_pause;
1374 #endif
1375
1376 #ifdef CONFIG_TRACING
1377         /* State flags for use by tracers: */
1378         unsigned long                   trace;
1379
1380         /* Bitmask and counter of trace recursion: */
1381         unsigned long                   trace_recursion;
1382 #endif /* CONFIG_TRACING */
1383
1384 #ifdef CONFIG_KCOV
1385         /* See kernel/kcov.c for more details. */
1386
1387         /* Coverage collection mode enabled for this task (0 if disabled): */
1388         unsigned int                    kcov_mode;
1389
1390         /* Size of the kcov_area: */
1391         unsigned int                    kcov_size;
1392
1393         /* Buffer for coverage collection: */
1394         void                            *kcov_area;
1395
1396         /* KCOV descriptor wired with this task or NULL: */
1397         struct kcov                     *kcov;
1398
1399         /* KCOV common handle for remote coverage collection: */
1400         u64                             kcov_handle;
1401
1402         /* KCOV sequence number: */
1403         int                             kcov_sequence;
1404
1405         /* Collect coverage from softirq context: */
1406         unsigned int                    kcov_softirq;
1407 #endif
1408
1409 #ifdef CONFIG_MEMCG
1410         struct mem_cgroup               *memcg_in_oom;
1411         gfp_t                           memcg_oom_gfp_mask;
1412         int                             memcg_oom_order;
1413
1414         /* Number of pages to reclaim on returning to userland: */
1415         unsigned int                    memcg_nr_pages_over_high;
1416
1417         /* Used by memcontrol for targeted memcg charge: */
1418         struct mem_cgroup               *active_memcg;
1419 #endif
1420
1421 #ifdef CONFIG_BLK_CGROUP
1422         struct request_queue            *throttle_queue;
1423 #endif
1424
1425 #ifdef CONFIG_UPROBES
1426         struct uprobe_task              *utask;
1427 #endif
1428 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1429         unsigned int                    sequential_io;
1430         unsigned int                    sequential_io_avg;
1431 #endif
1432         struct kmap_ctrl                kmap_ctrl;
1433 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1434         unsigned long                   task_state_change;
1435 # ifdef CONFIG_PREEMPT_RT
1436         unsigned long                   saved_state_change;
1437 # endif
1438 #endif
1439         int                             pagefault_disabled;
1440 #ifdef CONFIG_MMU
1441         struct task_struct              *oom_reaper_list;
1442 #endif
1443 #ifdef CONFIG_VMAP_STACK
1444         struct vm_struct                *stack_vm_area;
1445 #endif
1446 #ifdef CONFIG_THREAD_INFO_IN_TASK
1447         /* A live task holds one reference: */
1448         refcount_t                      stack_refcount;
1449 #endif
1450 #ifdef CONFIG_LIVEPATCH
1451         int patch_state;
1452 #endif
1453 #ifdef CONFIG_SECURITY
1454         /* Used by LSM modules for access restriction: */
1455         void                            *security;
1456 #endif
1457 #ifdef CONFIG_BPF_SYSCALL
1458         /* Used by BPF task local storage */
1459         struct bpf_local_storage __rcu  *bpf_storage;
1460         /* Used for BPF run context */
1461         struct bpf_run_ctx              *bpf_ctx;
1462 #endif
1463
1464 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK
1465         unsigned long                   lowest_stack;
1466         unsigned long                   prev_lowest_stack;
1467 #endif
1468
1469 #ifdef CONFIG_X86_MCE
1470         void __user                     *mce_vaddr;
1471         __u64                           mce_kflags;
1472         u64                             mce_addr;
1473         __u64                           mce_ripv : 1,
1474                                         mce_whole_page : 1,
1475                                         __mce_reserved : 62;
1476         struct callback_head            mce_kill_me;
1477         int                             mce_count;
1478 #endif
1479
1480 #ifdef CONFIG_KRETPROBES
1481         struct llist_head               kretprobe_instances;
1482 #endif
1483
1484 #ifdef CONFIG_ARCH_HAS_PARANOID_L1D_FLUSH
1485         /*
1486          * If L1D flush is supported on mm context switch
1487          * then we use this callback head to queue kill work
1488          * to kill tasks that are not running on SMT disabled
1489          * cores
1490          */
1491         struct callback_head            l1d_flush_kill;
1492 #endif
1493
1494         /*
1495          * New fields for task_struct should be added above here, so that
1496          * they are included in the randomized portion of task_struct.
1497          */
1498         randomized_struct_fields_end
1499
1500         /* CPU-specific state of this task: */
1501         struct thread_struct            thread;
1502
1503         /*
1504          * WARNING: on x86, 'thread_struct' contains a variable-sized
1505          * structure.  It *MUST* be at the end of 'task_struct'.
1506          *
1507          * Do not put anything below here!
1508          */
1509 };
1510
1511 static inline struct pid *task_pid(struct task_struct *task)
1512 {
1513         return task->thread_pid;
1514 }
1515
1516 /*
1517  * the helpers to get the task's different pids as they are seen
1518  * from various namespaces
1519  *
1520  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1521  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1522  *                     current.
1523  * task_xid_nr_ns()  : id seen from the ns specified;
1524  *
1525  * see also pid_nr() etc in include/linux/pid.h
1526  */
1527 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns);
1528
1529 static inline pid_t task_pid_nr(struct task_struct *tsk)
1530 {
1531         return tsk->pid;
1532 }
1533
1534 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1535 {
1536         return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1537 }
1538
1539 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1540 {
1541         return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1542 }
1543
1544
1545 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1546 {
1547         return tsk->tgid;
1548 }
1549
1550 /**
1551  * pid_alive - check that a task structure is not stale
1552  * @p: Task structure to be checked.
1553  *
1554  * Test if a process is not yet dead (at most zombie state)
1555  * If pid_alive fails, then pointers within the task structure
1556  * can be stale and must not be dereferenced.
1557  *
1558  * Return: 1 if the process is alive. 0 otherwise.
1559  */
1560 static inline int pid_alive(const struct task_struct *p)
1561 {
1562         return p->thread_pid != NULL;
1563 }
1564
1565 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1566 {
1567         return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1568 }
1569
1570 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1571 {
1572         return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1573 }
1574
1575
1576 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1577 {
1578         return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1579 }
1580
1581 static inline pid_t task_session_vnr(struct task_struct *tsk)
1582 {
1583         return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1584 }
1585
1586 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1587 {
1588         return __task_pid_nr_ns(tsk, PIDTYPE_TGID, ns);
1589 }
1590
1591 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1592 {
1593         return __task_pid_nr_ns(tsk, PIDTYPE_TGID, NULL);
1594 }
1595
1596 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1597 {
1598         pid_t pid = 0;
1599
1600         rcu_read_lock();
1601         if (pid_alive(tsk))
1602                 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1603         rcu_read_unlock();
1604
1605         return pid;
1606 }
1607
1608 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1609 {
1610         return task_ppid_nr_ns(tsk, &init_pid_ns);
1611 }
1612
1613 /* Obsolete, do not use: */
1614 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1615 {
1616         return task_pgrp_nr_ns(tsk, &init_pid_ns);
1617 }
1618
1619 #define TASK_REPORT_IDLE        (TASK_REPORT + 1)
1620 #define TASK_REPORT_MAX         (TASK_REPORT_IDLE << 1)
1621
1622 static inline unsigned int task_state_index(struct task_struct *tsk)
1623 {
1624         unsigned int tsk_state = READ_ONCE(tsk->__state);
1625         unsigned int state = (tsk_state | tsk->exit_state) & TASK_REPORT;
1626
1627         BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX);
1628
1629         if (tsk_state == TASK_IDLE)
1630                 state = TASK_REPORT_IDLE;
1631
1632         return fls(state);
1633 }
1634
1635 static inline char task_index_to_char(unsigned int state)
1636 {
1637         static const char state_char[] = "RSDTtXZPI";
1638
1639         BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1);
1640
1641         return state_char[state];
1642 }
1643
1644 static inline char task_state_to_char(struct task_struct *tsk)
1645 {
1646         return task_index_to_char(task_state_index(tsk));
1647 }
1648
1649 /**
1650  * is_global_init - check if a task structure is init. Since init
1651  * is free to have sub-threads we need to check tgid.
1652  * @tsk: Task structure to be checked.
1653  *
1654  * Check if a task structure is the first user space task the kernel created.
1655  *
1656  * Return: 1 if the task structure is init. 0 otherwise.
1657  */
1658 static inline int is_global_init(struct task_struct *tsk)
1659 {
1660         return task_tgid_nr(tsk) == 1;
1661 }
1662
1663 extern struct pid *cad_pid;
1664
1665 /*
1666  * Per process flags
1667  */
1668 #define PF_VCPU                 0x00000001      /* I'm a virtual CPU */
1669 #define PF_IDLE                 0x00000002      /* I am an IDLE thread */
1670 #define PF_EXITING              0x00000004      /* Getting shut down */
1671 #define PF_POSTCOREDUMP         0x00000008      /* Coredumps should ignore this task */
1672 #define PF_IO_WORKER            0x00000010      /* Task is an IO worker */
1673 #define PF_WQ_WORKER            0x00000020      /* I'm a workqueue worker */
1674 #define PF_FORKNOEXEC           0x00000040      /* Forked but didn't exec */
1675 #define PF_MCE_PROCESS          0x00000080      /* Process policy on mce errors */
1676 #define PF_SUPERPRIV            0x00000100      /* Used super-user privileges */
1677 #define PF_DUMPCORE             0x00000200      /* Dumped core */
1678 #define PF_SIGNALED             0x00000400      /* Killed by a signal */
1679 #define PF_MEMALLOC             0x00000800      /* Allocating memory */
1680 #define PF_NPROC_EXCEEDED       0x00001000      /* set_user() noticed that RLIMIT_NPROC was exceeded */
1681 #define PF_USED_MATH            0x00002000      /* If unset the fpu must be initialized before use */
1682 #define PF_USED_ASYNC           0x00004000      /* Used async_schedule*(), used by module init */
1683 #define PF_NOFREEZE             0x00008000      /* This thread should not be frozen */
1684 #define PF_FROZEN               0x00010000      /* Frozen for system suspend */
1685 #define PF_KSWAPD               0x00020000      /* I am kswapd */
1686 #define PF_MEMALLOC_NOFS        0x00040000      /* All allocation requests will inherit GFP_NOFS */
1687 #define PF_MEMALLOC_NOIO        0x00080000      /* All allocation requests will inherit GFP_NOIO */
1688 #define PF_LOCAL_THROTTLE       0x00100000      /* Throttle writes only against the bdi I write to,
1689                                                  * I am cleaning dirty pages from some other bdi. */
1690 #define PF_KTHREAD              0x00200000      /* I am a kernel thread */
1691 #define PF_RANDOMIZE            0x00400000      /* Randomize virtual address space */
1692 #define PF_SWAPWRITE            0x00800000      /* Allowed to write to swap */
1693 #define PF_NO_SETAFFINITY       0x04000000      /* Userland is not allowed to meddle with cpus_mask */
1694 #define PF_MCE_EARLY            0x08000000      /* Early kill for mce process policy */
1695 #define PF_MEMALLOC_PIN         0x10000000      /* Allocation context constrained to zones which allow long term pinning. */
1696 #define PF_FREEZER_SKIP         0x40000000      /* Freezer should not count it as freezable */
1697 #define PF_SUSPEND_TASK         0x80000000      /* This thread called freeze_processes() and should not be frozen */
1698
1699 /*
1700  * Only the _current_ task can read/write to tsk->flags, but other
1701  * tasks can access tsk->flags in readonly mode for example
1702  * with tsk_used_math (like during threaded core dumping).
1703  * There is however an exception to this rule during ptrace
1704  * or during fork: the ptracer task is allowed to write to the
1705  * child->flags of its traced child (same goes for fork, the parent
1706  * can write to the child->flags), because we're guaranteed the
1707  * child is not running and in turn not changing child->flags
1708  * at the same time the parent does it.
1709  */
1710 #define clear_stopped_child_used_math(child)    do { (child)->flags &= ~PF_USED_MATH; } while (0)
1711 #define set_stopped_child_used_math(child)      do { (child)->flags |= PF_USED_MATH; } while (0)
1712 #define clear_used_math()                       clear_stopped_child_used_math(current)
1713 #define set_used_math()                         set_stopped_child_used_math(current)
1714
1715 #define conditional_stopped_child_used_math(condition, child) \
1716         do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1717
1718 #define conditional_used_math(condition)        conditional_stopped_child_used_math(condition, current)
1719
1720 #define copy_to_stopped_child_used_math(child) \
1721         do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1722
1723 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1724 #define tsk_used_math(p)                        ((p)->flags & PF_USED_MATH)
1725 #define used_math()                             tsk_used_math(current)
1726
1727 static __always_inline bool is_percpu_thread(void)
1728 {
1729 #ifdef CONFIG_SMP
1730         return (current->flags & PF_NO_SETAFFINITY) &&
1731                 (current->nr_cpus_allowed  == 1);
1732 #else
1733         return true;
1734 #endif
1735 }
1736
1737 /* Per-process atomic flags. */
1738 #define PFA_NO_NEW_PRIVS                0       /* May not gain new privileges. */
1739 #define PFA_SPREAD_PAGE                 1       /* Spread page cache over cpuset */
1740 #define PFA_SPREAD_SLAB                 2       /* Spread some slab caches over cpuset */
1741 #define PFA_SPEC_SSB_DISABLE            3       /* Speculative Store Bypass disabled */
1742 #define PFA_SPEC_SSB_FORCE_DISABLE      4       /* Speculative Store Bypass force disabled*/
1743 #define PFA_SPEC_IB_DISABLE             5       /* Indirect branch speculation restricted */
1744 #define PFA_SPEC_IB_FORCE_DISABLE       6       /* Indirect branch speculation permanently restricted */
1745 #define PFA_SPEC_SSB_NOEXEC             7       /* Speculative Store Bypass clear on execve() */
1746
1747 #define TASK_PFA_TEST(name, func)                                       \
1748         static inline bool task_##func(struct task_struct *p)           \
1749         { return test_bit(PFA_##name, &p->atomic_flags); }
1750
1751 #define TASK_PFA_SET(name, func)                                        \
1752         static inline void task_set_##func(struct task_struct *p)       \
1753         { set_bit(PFA_##name, &p->atomic_flags); }
1754
1755 #define TASK_PFA_CLEAR(name, func)                                      \
1756         static inline void task_clear_##func(struct task_struct *p)     \
1757         { clear_bit(PFA_##name, &p->atomic_flags); }
1758
1759 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
1760 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
1761
1762 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
1763 TASK_PFA_SET(SPREAD_PAGE, spread_page)
1764 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
1765
1766 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
1767 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
1768 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
1769
1770 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable)
1771 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable)
1772 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable)
1773
1774 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1775 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1776 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1777
1778 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1779 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1780
1781 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable)
1782 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable)
1783 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable)
1784
1785 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1786 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1787
1788 static inline void
1789 current_restore_flags(unsigned long orig_flags, unsigned long flags)
1790 {
1791         current->flags &= ~flags;
1792         current->flags |= orig_flags & flags;
1793 }
1794
1795 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
1796 extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed);
1797 #ifdef CONFIG_SMP
1798 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
1799 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
1800 extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node);
1801 extern void release_user_cpus_ptr(struct task_struct *p);
1802 extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask);
1803 extern void force_compatible_cpus_allowed_ptr(struct task_struct *p);
1804 extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p);
1805 #else
1806 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
1807 {
1808 }
1809 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
1810 {
1811         if (!cpumask_test_cpu(0, new_mask))
1812                 return -EINVAL;
1813         return 0;
1814 }
1815 static inline int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node)
1816 {
1817         if (src->user_cpus_ptr)
1818                 return -EINVAL;
1819         return 0;
1820 }
1821 static inline void release_user_cpus_ptr(struct task_struct *p)
1822 {
1823         WARN_ON(p->user_cpus_ptr);
1824 }
1825
1826 static inline int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask)
1827 {
1828         return 0;
1829 }
1830 #endif
1831
1832 extern int yield_to(struct task_struct *p, bool preempt);
1833 extern void set_user_nice(struct task_struct *p, long nice);
1834 extern int task_prio(const struct task_struct *p);
1835
1836 /**
1837  * task_nice - return the nice value of a given task.
1838  * @p: the task in question.
1839  *
1840  * Return: The nice value [ -20 ... 0 ... 19 ].
1841  */
1842 static inline int task_nice(const struct task_struct *p)
1843 {
1844         return PRIO_TO_NICE((p)->static_prio);
1845 }
1846
1847 extern int can_nice(const struct task_struct *p, const int nice);
1848 extern int task_curr(const struct task_struct *p);
1849 extern int idle_cpu(int cpu);
1850 extern int available_idle_cpu(int cpu);
1851 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *);
1852 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *);
1853 extern void sched_set_fifo(struct task_struct *p);
1854 extern void sched_set_fifo_low(struct task_struct *p);
1855 extern void sched_set_normal(struct task_struct *p, int nice);
1856 extern int sched_setattr(struct task_struct *, const struct sched_attr *);
1857 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *);
1858 extern struct task_struct *idle_task(int cpu);
1859
1860 /**
1861  * is_idle_task - is the specified task an idle task?
1862  * @p: the task in question.
1863  *
1864  * Return: 1 if @p is an idle task. 0 otherwise.
1865  */
1866 static __always_inline bool is_idle_task(const struct task_struct *p)
1867 {
1868         return !!(p->flags & PF_IDLE);
1869 }
1870
1871 extern struct task_struct *curr_task(int cpu);
1872 extern void ia64_set_curr_task(int cpu, struct task_struct *p);
1873
1874 void yield(void);
1875
1876 union thread_union {
1877 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK
1878         struct task_struct task;
1879 #endif
1880 #ifndef CONFIG_THREAD_INFO_IN_TASK
1881         struct thread_info thread_info;
1882 #endif
1883         unsigned long stack[THREAD_SIZE/sizeof(long)];
1884 };
1885
1886 #ifndef CONFIG_THREAD_INFO_IN_TASK
1887 extern struct thread_info init_thread_info;
1888 #endif
1889
1890 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
1891
1892 #ifdef CONFIG_THREAD_INFO_IN_TASK
1893 # define task_thread_info(task) (&(task)->thread_info)
1894 #elif !defined(__HAVE_THREAD_FUNCTIONS)
1895 # define task_thread_info(task) ((struct thread_info *)(task)->stack)
1896 #endif
1897
1898 /*
1899  * find a task by one of its numerical ids
1900  *
1901  * find_task_by_pid_ns():
1902  *      finds a task by its pid in the specified namespace
1903  * find_task_by_vpid():
1904  *      finds a task by its virtual pid
1905  *
1906  * see also find_vpid() etc in include/linux/pid.h
1907  */
1908
1909 extern struct task_struct *find_task_by_vpid(pid_t nr);
1910 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns);
1911
1912 /*
1913  * find a task by its virtual pid and get the task struct
1914  */
1915 extern struct task_struct *find_get_task_by_vpid(pid_t nr);
1916
1917 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
1918 extern int wake_up_process(struct task_struct *tsk);
1919 extern void wake_up_new_task(struct task_struct *tsk);
1920
1921 #ifdef CONFIG_SMP
1922 extern void kick_process(struct task_struct *tsk);
1923 #else
1924 static inline void kick_process(struct task_struct *tsk) { }
1925 #endif
1926
1927 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
1928
1929 static inline void set_task_comm(struct task_struct *tsk, const char *from)
1930 {
1931         __set_task_comm(tsk, from, false);
1932 }
1933
1934 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk);
1935 #define get_task_comm(buf, tsk) ({                      \
1936         BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN);     \
1937         __get_task_comm(buf, sizeof(buf), tsk);         \
1938 })
1939
1940 #ifdef CONFIG_SMP
1941 static __always_inline void scheduler_ipi(void)
1942 {
1943         /*
1944          * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting
1945          * TIF_NEED_RESCHED remotely (for the first time) will also send
1946          * this IPI.
1947          */
1948         preempt_fold_need_resched();
1949 }
1950 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state);
1951 #else
1952 static inline void scheduler_ipi(void) { }
1953 static inline unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state)
1954 {
1955         return 1;
1956 }
1957 #endif
1958
1959 /*
1960  * Set thread flags in other task's structures.
1961  * See asm/thread_info.h for TIF_xxxx flags available:
1962  */
1963 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
1964 {
1965         set_ti_thread_flag(task_thread_info(tsk), flag);
1966 }
1967
1968 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1969 {
1970         clear_ti_thread_flag(task_thread_info(tsk), flag);
1971 }
1972
1973 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag,
1974                                           bool value)
1975 {
1976         update_ti_thread_flag(task_thread_info(tsk), flag, value);
1977 }
1978
1979 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
1980 {
1981         return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
1982 }
1983
1984 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1985 {
1986         return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
1987 }
1988
1989 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
1990 {
1991         return test_ti_thread_flag(task_thread_info(tsk), flag);
1992 }
1993
1994 static inline void set_tsk_need_resched(struct task_struct *tsk)
1995 {
1996         set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1997 }
1998
1999 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2000 {
2001         clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2002 }
2003
2004 static inline int test_tsk_need_resched(struct task_struct *tsk)
2005 {
2006         return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2007 }
2008
2009 /*
2010  * cond_resched() and cond_resched_lock(): latency reduction via
2011  * explicit rescheduling in places that are safe. The return
2012  * value indicates whether a reschedule was done in fact.
2013  * cond_resched_lock() will drop the spinlock before scheduling,
2014  */
2015 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC)
2016 extern int __cond_resched(void);
2017
2018 #ifdef CONFIG_PREEMPT_DYNAMIC
2019
2020 DECLARE_STATIC_CALL(cond_resched, __cond_resched);
2021
2022 static __always_inline int _cond_resched(void)
2023 {
2024         return static_call_mod(cond_resched)();
2025 }
2026
2027 #else
2028
2029 static inline int _cond_resched(void)
2030 {
2031         return __cond_resched();
2032 }
2033
2034 #endif /* CONFIG_PREEMPT_DYNAMIC */
2035
2036 #else
2037
2038 static inline int _cond_resched(void) { return 0; }
2039
2040 #endif /* !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) */
2041
2042 #define cond_resched() ({                       \
2043         __might_resched(__FILE__, __LINE__, 0); \
2044         _cond_resched();                        \
2045 })
2046
2047 extern int __cond_resched_lock(spinlock_t *lock);
2048 extern int __cond_resched_rwlock_read(rwlock_t *lock);
2049 extern int __cond_resched_rwlock_write(rwlock_t *lock);
2050
2051 #define MIGHT_RESCHED_RCU_SHIFT         8
2052 #define MIGHT_RESCHED_PREEMPT_MASK      ((1U << MIGHT_RESCHED_RCU_SHIFT) - 1)
2053
2054 #ifndef CONFIG_PREEMPT_RT
2055 /*
2056  * Non RT kernels have an elevated preempt count due to the held lock,
2057  * but are not allowed to be inside a RCU read side critical section
2058  */
2059 # define PREEMPT_LOCK_RESCHED_OFFSETS   PREEMPT_LOCK_OFFSET
2060 #else
2061 /*
2062  * spin/rw_lock() on RT implies rcu_read_lock(). The might_sleep() check in
2063  * cond_resched*lock() has to take that into account because it checks for
2064  * preempt_count() and rcu_preempt_depth().
2065  */
2066 # define PREEMPT_LOCK_RESCHED_OFFSETS   \
2067         (PREEMPT_LOCK_OFFSET + (1U << MIGHT_RESCHED_RCU_SHIFT))
2068 #endif
2069
2070 #define cond_resched_lock(lock) ({                                              \
2071         __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS);      \
2072         __cond_resched_lock(lock);                                              \
2073 })
2074
2075 #define cond_resched_rwlock_read(lock) ({                                       \
2076         __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS);      \
2077         __cond_resched_rwlock_read(lock);                                       \
2078 })
2079
2080 #define cond_resched_rwlock_write(lock) ({                                      \
2081         __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS);      \
2082         __cond_resched_rwlock_write(lock);                                      \
2083 })
2084
2085 static inline void cond_resched_rcu(void)
2086 {
2087 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
2088         rcu_read_unlock();
2089         cond_resched();
2090         rcu_read_lock();
2091 #endif
2092 }
2093
2094 /*
2095  * Does a critical section need to be broken due to another
2096  * task waiting?: (technically does not depend on CONFIG_PREEMPTION,
2097  * but a general need for low latency)
2098  */
2099 static inline int spin_needbreak(spinlock_t *lock)
2100 {
2101 #ifdef CONFIG_PREEMPTION
2102         return spin_is_contended(lock);
2103 #else
2104         return 0;
2105 #endif
2106 }
2107
2108 /*
2109  * Check if a rwlock is contended.
2110  * Returns non-zero if there is another task waiting on the rwlock.
2111  * Returns zero if the lock is not contended or the system / underlying
2112  * rwlock implementation does not support contention detection.
2113  * Technically does not depend on CONFIG_PREEMPTION, but a general need
2114  * for low latency.
2115  */
2116 static inline int rwlock_needbreak(rwlock_t *lock)
2117 {
2118 #ifdef CONFIG_PREEMPTION
2119         return rwlock_is_contended(lock);
2120 #else
2121         return 0;
2122 #endif
2123 }
2124
2125 static __always_inline bool need_resched(void)
2126 {
2127         return unlikely(tif_need_resched());
2128 }
2129
2130 /*
2131  * Wrappers for p->thread_info->cpu access. No-op on UP.
2132  */
2133 #ifdef CONFIG_SMP
2134
2135 static inline unsigned int task_cpu(const struct task_struct *p)
2136 {
2137         return READ_ONCE(task_thread_info(p)->cpu);
2138 }
2139
2140 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2141
2142 #else
2143
2144 static inline unsigned int task_cpu(const struct task_struct *p)
2145 {
2146         return 0;
2147 }
2148
2149 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2150 {
2151 }
2152
2153 #endif /* CONFIG_SMP */
2154
2155 extern bool sched_task_on_rq(struct task_struct *p);
2156 extern unsigned long get_wchan(struct task_struct *p);
2157
2158 /*
2159  * In order to reduce various lock holder preemption latencies provide an
2160  * interface to see if a vCPU is currently running or not.
2161  *
2162  * This allows us to terminate optimistic spin loops and block, analogous to
2163  * the native optimistic spin heuristic of testing if the lock owner task is
2164  * running or not.
2165  */
2166 #ifndef vcpu_is_preempted
2167 static inline bool vcpu_is_preempted(int cpu)
2168 {
2169         return false;
2170 }
2171 #endif
2172
2173 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2174 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2175
2176 #ifndef TASK_SIZE_OF
2177 #define TASK_SIZE_OF(tsk)       TASK_SIZE
2178 #endif
2179
2180 #ifdef CONFIG_SMP
2181 static inline bool owner_on_cpu(struct task_struct *owner)
2182 {
2183         /*
2184          * As lock holder preemption issue, we both skip spinning if
2185          * task is not on cpu or its cpu is preempted
2186          */
2187         return READ_ONCE(owner->on_cpu) && !vcpu_is_preempted(task_cpu(owner));
2188 }
2189
2190 /* Returns effective CPU energy utilization, as seen by the scheduler */
2191 unsigned long sched_cpu_util(int cpu, unsigned long max);
2192 #endif /* CONFIG_SMP */
2193
2194 #ifdef CONFIG_RSEQ
2195
2196 /*
2197  * Map the event mask on the user-space ABI enum rseq_cs_flags
2198  * for direct mask checks.
2199  */
2200 enum rseq_event_mask_bits {
2201         RSEQ_EVENT_PREEMPT_BIT  = RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT,
2202         RSEQ_EVENT_SIGNAL_BIT   = RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT,
2203         RSEQ_EVENT_MIGRATE_BIT  = RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT,
2204 };
2205
2206 enum rseq_event_mask {
2207         RSEQ_EVENT_PREEMPT      = (1U << RSEQ_EVENT_PREEMPT_BIT),
2208         RSEQ_EVENT_SIGNAL       = (1U << RSEQ_EVENT_SIGNAL_BIT),
2209         RSEQ_EVENT_MIGRATE      = (1U << RSEQ_EVENT_MIGRATE_BIT),
2210 };
2211
2212 static inline void rseq_set_notify_resume(struct task_struct *t)
2213 {
2214         if (t->rseq)
2215                 set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
2216 }
2217
2218 void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs);
2219
2220 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
2221                                              struct pt_regs *regs)
2222 {
2223         if (current->rseq)
2224                 __rseq_handle_notify_resume(ksig, regs);
2225 }
2226
2227 static inline void rseq_signal_deliver(struct ksignal *ksig,
2228                                        struct pt_regs *regs)
2229 {
2230         preempt_disable();
2231         __set_bit(RSEQ_EVENT_SIGNAL_BIT, &current->rseq_event_mask);
2232         preempt_enable();
2233         rseq_handle_notify_resume(ksig, regs);
2234 }
2235
2236 /* rseq_preempt() requires preemption to be disabled. */
2237 static inline void rseq_preempt(struct task_struct *t)
2238 {
2239         __set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask);
2240         rseq_set_notify_resume(t);
2241 }
2242
2243 /* rseq_migrate() requires preemption to be disabled. */
2244 static inline void rseq_migrate(struct task_struct *t)
2245 {
2246         __set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask);
2247         rseq_set_notify_resume(t);
2248 }
2249
2250 /*
2251  * If parent process has a registered restartable sequences area, the
2252  * child inherits. Unregister rseq for a clone with CLONE_VM set.
2253  */
2254 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
2255 {
2256         if (clone_flags & CLONE_VM) {
2257                 t->rseq = NULL;
2258                 t->rseq_sig = 0;
2259                 t->rseq_event_mask = 0;
2260         } else {
2261                 t->rseq = current->rseq;
2262                 t->rseq_sig = current->rseq_sig;
2263                 t->rseq_event_mask = current->rseq_event_mask;
2264         }
2265 }
2266
2267 static inline void rseq_execve(struct task_struct *t)
2268 {
2269         t->rseq = NULL;
2270         t->rseq_sig = 0;
2271         t->rseq_event_mask = 0;
2272 }
2273
2274 #else
2275
2276 static inline void rseq_set_notify_resume(struct task_struct *t)
2277 {
2278 }
2279 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
2280                                              struct pt_regs *regs)
2281 {
2282 }
2283 static inline void rseq_signal_deliver(struct ksignal *ksig,
2284                                        struct pt_regs *regs)
2285 {
2286 }
2287 static inline void rseq_preempt(struct task_struct *t)
2288 {
2289 }
2290 static inline void rseq_migrate(struct task_struct *t)
2291 {
2292 }
2293 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
2294 {
2295 }
2296 static inline void rseq_execve(struct task_struct *t)
2297 {
2298 }
2299
2300 #endif
2301
2302 #ifdef CONFIG_DEBUG_RSEQ
2303
2304 void rseq_syscall(struct pt_regs *regs);
2305
2306 #else
2307
2308 static inline void rseq_syscall(struct pt_regs *regs)
2309 {
2310 }
2311
2312 #endif
2313
2314 const struct sched_avg *sched_trace_cfs_rq_avg(struct cfs_rq *cfs_rq);
2315 char *sched_trace_cfs_rq_path(struct cfs_rq *cfs_rq, char *str, int len);
2316 int sched_trace_cfs_rq_cpu(struct cfs_rq *cfs_rq);
2317
2318 const struct sched_avg *sched_trace_rq_avg_rt(struct rq *rq);
2319 const struct sched_avg *sched_trace_rq_avg_dl(struct rq *rq);
2320 const struct sched_avg *sched_trace_rq_avg_irq(struct rq *rq);
2321
2322 int sched_trace_rq_cpu(struct rq *rq);
2323 int sched_trace_rq_cpu_capacity(struct rq *rq);
2324 int sched_trace_rq_nr_running(struct rq *rq);
2325
2326 const struct cpumask *sched_trace_rd_span(struct root_domain *rd);
2327
2328 #ifdef CONFIG_SCHED_CORE
2329 extern void sched_core_free(struct task_struct *tsk);
2330 extern void sched_core_fork(struct task_struct *p);
2331 extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type,
2332                                 unsigned long uaddr);
2333 #else
2334 static inline void sched_core_free(struct task_struct *tsk) { }
2335 static inline void sched_core_fork(struct task_struct *p) { }
2336 #endif
2337
2338 #endif