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/kmsan_types.h>
  18 #include <linux/mutex.h>
  19 #include <linux/plist.h>
  20 #include <linux/hrtimer.h>
  21 #include <linux/irqflags.h>
  22 #include <linux/seccomp.h>
  23 #include <linux/nodemask.h>
  24 #include <linux/rcupdate.h>
  25 #include <linux/refcount.h>
  26 #include <linux/resource.h>
  27 #include <linux/latencytop.h>
  28 #include <linux/sched/prio.h>
  29 #include <linux/sched/types.h>
  30 #include <linux/signal_types.h>
  31 #include <linux/syscall_user_dispatch.h>
  32 #include <linux/mm_types_task.h>
  33 #include <linux/task_io_accounting.h>
  34 #include <linux/posix-timers.h>
  35 #include <linux/rseq.h>
  36 #include <linux/seqlock.h>
  37 #include <linux/kcsan.h>
  38 #include <linux/rv.h>
  39 #include <linux/livepatch_sched.h>
  40 #include <asm/kmap_size.h>
  41
  42 /* task_struct member predeclarations (sorted alphabetically): */
  43 struct audit_context;
  44 struct backing_dev_info;
  45 struct bio_list;
  46 struct blk_plug;
  47 struct bpf_local_storage;
  48 struct bpf_run_ctx;
  49 struct capture_control;
  50 struct cfs_rq;
  51 struct fs_struct;
  52 struct futex_pi_state;
  53 struct io_context;
  54 struct io_uring_task;
  55 struct mempolicy;
  56 struct nameidata;
  57 struct nsproxy;
  58 struct perf_event_context;
  59 struct pid_namespace;
  60 struct pipe_inode_info;
  61 struct rcu_node;
  62 struct reclaim_state;
  63 struct robust_list_head;
  64 struct root_domain;
  65 struct rq;
  66 struct sched_attr;
  67 struct sched_param;
  68 struct seq_file;
  69 struct sighand_struct;
  70 struct signal_struct;
  71 struct task_delay_info;
  72 struct task_group;
  73 struct user_event_mm;
  74
  75 /*
  76  * Task state bitmask. NOTE! These bits are also
  77  * encoded in fs/proc/array.c: get_task_state().
  78  *
  79  * We have two separate sets of flags: task->state
  80  * is about runnability, while task->exit_state are
  81  * about the task exiting. Confusing, but this way
  82  * modifying one set can't modify the other one by
  83  * mistake.
  84  */
  85
  86 /* Used in tsk->state: */
  87 #define TASK_RUNNING                    0x00000000
  88 #define TASK_INTERRUPTIBLE              0x00000001
  89 #define TASK_UNINTERRUPTIBLE            0x00000002
  90 #define __TASK_STOPPED                  0x00000004
  91 #define __TASK_TRACED                   0x00000008
  92 /* Used in tsk->exit_state: */
  93 #define EXIT_DEAD                       0x00000010
  94 #define EXIT_ZOMBIE                     0x00000020
  95 #define EXIT_TRACE                      (EXIT_ZOMBIE | EXIT_DEAD)
  96 /* Used in tsk->state again: */
  97 #define TASK_PARKED                     0x00000040
  98 #define TASK_DEAD                       0x00000080
  99 #define TASK_WAKEKILL                   0x00000100
 100 #define TASK_WAKING                     0x00000200
 101 #define TASK_NOLOAD                     0x00000400
 102 #define TASK_NEW                        0x00000800
 103 #define TASK_RTLOCK_WAIT                0x00001000
 104 #define TASK_FREEZABLE                  0x00002000
 105 #define __TASK_FREEZABLE_UNSAFE        (0x00004000 * IS_ENABLED(CONFIG_LOCKDEP))
 106 #define TASK_FROZEN                     0x00008000
 107 #define TASK_STATE_MAX                  0x00010000
 108
 109 #define TASK_ANY                        (TASK_STATE_MAX-1)
 110
 111 /*
 112  * DO NOT ADD ANY NEW USERS !
 113  */
 114 #define TASK_FREEZABLE_UNSAFE           (TASK_FREEZABLE | __TASK_FREEZABLE_UNSAFE)
 115
 116 /* Convenience macros for the sake of set_current_state: */
 117 #define TASK_KILLABLE                   (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
 118 #define TASK_STOPPED                    (TASK_WAKEKILL | __TASK_STOPPED)
 119 #define TASK_TRACED                     __TASK_TRACED
 120
 121 #define TASK_IDLE                       (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
 122
 123 /* Convenience macros for the sake of wake_up(): */
 124 #define TASK_NORMAL                     (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
 125
 126 /* get_task_state(): */
 127 #define TASK_REPORT                     (TASK_RUNNING | TASK_INTERRUPTIBLE | \
 128                                          TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
 129                                          __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
 130                                          TASK_PARKED)
 131
 132 #define task_is_running(task)           (READ_ONCE((task)->__state) == TASK_RUNNING)
 133
 134 #define task_is_traced(task)            ((READ_ONCE(task->jobctl) & JOBCTL_TRACED) != 0)
 135 #define task_is_stopped(task)           ((READ_ONCE(task->jobctl) & JOBCTL_STOPPED) != 0)
 136 #define task_is_stopped_or_traced(task) ((READ_ONCE(task->jobctl) & (JOBCTL_STOPPED | JOBCTL_TRACED)) != 0)
 137
 138 /*
 139  * Special states are those that do not use the normal wait-loop pattern. See
 140  * the comment with set_special_state().
 141  */
 142 #define is_special_task_state(state)                            \
 143         ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD))
 144
 145 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
 146 # define debug_normal_state_change(state_value)                         \
 147         do {                                                            \
 148                 WARN_ON_ONCE(is_special_task_state(state_value));       \
 149                 current->task_state_change = _THIS_IP_;                 \
 150         } while (0)
 151
 152 # define debug_special_state_change(state_value)                        \
 153         do {                                                            \
 154                 WARN_ON_ONCE(!is_special_task_state(state_value));      \
 155                 current->task_state_change = _THIS_IP_;                 \
 156         } while (0)
 157
 158 # define debug_rtlock_wait_set_state()                                  \
 159         do {                                                             \
 160                 current->saved_state_change = current->task_state_change;\
 161                 current->task_state_change = _THIS_IP_;                  \
 162         } while (0)
 163
 164 # define debug_rtlock_wait_restore_state()                              \
 165         do {                                                             \
 166                 current->task_state_change = current->saved_state_change;\
 167         } while (0)
 168
 169 #else
 170 # define debug_normal_state_change(cond)        do { } while (0)
 171 # define debug_special_state_change(cond)       do { } while (0)
 172 # define debug_rtlock_wait_set_state()          do { } while (0)
 173 # define debug_rtlock_wait_restore_state()      do { } while (0)
 174 #endif
 175
 176 /*
 177  * set_current_state() includes a barrier so that the write of current->state
 178  * is correctly serialised wrt the caller's subsequent test of whether to
 179  * actually sleep:
 180  *
 181  *   for (;;) {
 182  *      set_current_state(TASK_UNINTERRUPTIBLE);
 183  *      if (CONDITION)
 184  *         break;
 185  *
 186  *      schedule();
 187  *   }
 188  *   __set_current_state(TASK_RUNNING);
 189  *
 190  * If the caller does not need such serialisation (because, for instance, the
 191  * CONDITION test and condition change and wakeup are under the same lock) then
 192  * use __set_current_state().
 193  *
 194  * The above is typically ordered against the wakeup, which does:
 195  *
 196  *   CONDITION = 1;
 197  *   wake_up_state(p, TASK_UNINTERRUPTIBLE);
 198  *
 199  * where wake_up_state()/try_to_wake_up() executes a full memory barrier before
 200  * accessing p->state.
 201  *
 202  * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is,
 203  * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
 204  * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
 205  *
 206  * However, with slightly different timing the wakeup TASK_RUNNING store can
 207  * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not
 208  * a problem either because that will result in one extra go around the loop
 209  * and our @cond test will save the day.
 210  *
 211  * Also see the comments of try_to_wake_up().
 212  */
 213 #define __set_current_state(state_value)                                \
 214         do {                                                            \
 215                 debug_normal_state_change((state_value));               \
 216                 WRITE_ONCE(current->__state, (state_value));            \
 217         } while (0)
 218
 219 #define set_current_state(state_value)                                  \
 220         do {                                                            \
 221                 debug_normal_state_change((state_value));               \
 222                 smp_store_mb(current->__state, (state_value));          \
 223         } while (0)
 224
 225 /*
 226  * set_special_state() should be used for those states when the blocking task
 227  * can not use the regular condition based wait-loop. In that case we must
 228  * serialize against wakeups such that any possible in-flight TASK_RUNNING
 229  * stores will not collide with our state change.
 230  */
 231 #define set_special_state(state_value)                                  \
 232         do {                                                            \
 233                 unsigned long flags; /* may shadow */                   \
 234                                                                         \
 235                 raw_spin_lock_irqsave(&current->pi_lock, flags);        \
 236                 debug_special_state_change((state_value));              \
 237                 WRITE_ONCE(current->__state, (state_value));            \
 238                 raw_spin_unlock_irqrestore(&current->pi_lock, flags);   \
 239         } while (0)
 240
 241 /*
 242  * PREEMPT_RT specific variants for "sleeping" spin/rwlocks
 243  *
 244  * RT's spin/rwlock substitutions are state preserving. The state of the
 245  * task when blocking on the lock is saved in task_struct::saved_state and
 246  * restored after the lock has been acquired.  These operations are
 247  * serialized by task_struct::pi_lock against try_to_wake_up(). Any non RT
 248  * lock related wakeups while the task is blocked on the lock are
 249  * redirected to operate on task_struct::saved_state to ensure that these
 250  * are not dropped. On restore task_struct::saved_state is set to
 251  * TASK_RUNNING so any wakeup attempt redirected to saved_state will fail.
 252  *
 253  * The lock operation looks like this:
 254  *
 255  *      current_save_and_set_rtlock_wait_state();
 256  *      for (;;) {
 257  *              if (try_lock())
 258  *                      break;
 259  *              raw_spin_unlock_irq(&lock->wait_lock);
 260  *              schedule_rtlock();
 261  *              raw_spin_lock_irq(&lock->wait_lock);
 262  *              set_current_state(TASK_RTLOCK_WAIT);
 263  *      }
 264  *      current_restore_rtlock_saved_state();
 265  */
 266 #define current_save_and_set_rtlock_wait_state()                        \
 267         do {                                                            \
 268                 lockdep_assert_irqs_disabled();                         \
 269                 raw_spin_lock(&current->pi_lock);                       \
 270                 current->saved_state = current->__state;                \
 271                 debug_rtlock_wait_set_state();                          \
 272                 WRITE_ONCE(current->__state, TASK_RTLOCK_WAIT);         \
 273                 raw_spin_unlock(&current->pi_lock);                     \
 274         } while (0);
 275
 276 #define current_restore_rtlock_saved_state()                            \
 277         do {                                                            \
 278                 lockdep_assert_irqs_disabled();                         \
 279                 raw_spin_lock(&current->pi_lock);                       \
 280                 debug_rtlock_wait_restore_state();                      \
 281                 WRITE_ONCE(current->__state, current->saved_state);     \
 282                 current->saved_state = TASK_RUNNING;                    \
 283                 raw_spin_unlock(&current->pi_lock);                     \
 284         } while (0);
 285
 286 #define get_current_state()     READ_ONCE(current->__state)
 287
 288 /*
 289  * Define the task command name length as enum, then it can be visible to
 290  * BPF programs.
 291  */
 292 enum {
 293         TASK_COMM_LEN = 16,
 294 };
 295
 296 extern void scheduler_tick(void);
 297
 298 #define MAX_SCHEDULE_TIMEOUT            LONG_MAX
 299
 300 extern long schedule_timeout(long timeout);
 301 extern long schedule_timeout_interruptible(long timeout);
 302 extern long schedule_timeout_killable(long timeout);
 303 extern long schedule_timeout_uninterruptible(long timeout);
 304 extern long schedule_timeout_idle(long timeout);
 305 asmlinkage void schedule(void);
 306 extern void schedule_preempt_disabled(void);
 307 asmlinkage void preempt_schedule_irq(void);
 308 #ifdef CONFIG_PREEMPT_RT
 309  extern void schedule_rtlock(void);
 310 #endif
 311
 312 extern int __must_check io_schedule_prepare(void);
 313 extern void io_schedule_finish(int token);
 314 extern long io_schedule_timeout(long timeout);
 315 extern void io_schedule(void);
 316
 317 /**
 318  * struct prev_cputime - snapshot of system and user cputime
 319  * @utime: time spent in user mode
 320  * @stime: time spent in system mode
 321  * @lock: protects the above two fields
 322  *
 323  * Stores previous user/system time values such that we can guarantee
 324  * monotonicity.
 325  */
 326 struct prev_cputime {
 327 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 328         u64                             utime;
 329         u64                             stime;
 330         raw_spinlock_t                  lock;
 331 #endif
 332 };
 333
 334 enum vtime_state {
 335         /* Task is sleeping or running in a CPU with VTIME inactive: */
 336         VTIME_INACTIVE = 0,
 337         /* Task is idle */
 338         VTIME_IDLE,
 339         /* Task runs in kernelspace in a CPU with VTIME active: */
 340         VTIME_SYS,
 341         /* Task runs in userspace in a CPU with VTIME active: */
 342         VTIME_USER,
 343         /* Task runs as guests in a CPU with VTIME active: */
 344         VTIME_GUEST,
 345 };
 346
 347 struct vtime {
 348         seqcount_t              seqcount;
 349         unsigned long long      starttime;
 350         enum vtime_state        state;
 351         unsigned int            cpu;
 352         u64                     utime;
 353         u64                     stime;
 354         u64                     gtime;
 355 };
 356
 357 /*
 358  * Utilization clamp constraints.
 359  * @UCLAMP_MIN: Minimum utilization
 360  * @UCLAMP_MAX: Maximum utilization
 361  * @UCLAMP_CNT: Utilization clamp constraints count
 362  */
 363 enum uclamp_id {
 364         UCLAMP_MIN = 0,
 365         UCLAMP_MAX,
 366         UCLAMP_CNT
 367 };
 368
 369 #ifdef CONFIG_SMP
 370 extern struct root_domain def_root_domain;
 371 extern struct mutex sched_domains_mutex;
 372 #endif
 373
 374 struct sched_info {
 375 #ifdef CONFIG_SCHED_INFO
 376         /* Cumulative counters: */
 377
 378         /* # of times we have run on this CPU: */
 379         unsigned long                   pcount;
 380
 381         /* Time spent waiting on a runqueue: */
 382         unsigned long long              run_delay;
 383
 384         /* Timestamps: */
 385
 386         /* When did we last run on a CPU? */
 387         unsigned long long              last_arrival;
 388
 389         /* When were we last queued to run? */
 390         unsigned long long              last_queued;
 391
 392 #endif /* CONFIG_SCHED_INFO */
 393 };
 394
 395 /*
 396  * Integer metrics need fixed point arithmetic, e.g., sched/fair
 397  * has a few: load, load_avg, util_avg, freq, and capacity.
 398  *
 399  * We define a basic fixed point arithmetic range, and then formalize
 400  * all these metrics based on that basic range.
 401  */
 402 # define SCHED_FIXEDPOINT_SHIFT         10
 403 # define SCHED_FIXEDPOINT_SCALE         (1L << SCHED_FIXEDPOINT_SHIFT)
 404
 405 /* Increase resolution of cpu_capacity calculations */
 406 # define SCHED_CAPACITY_SHIFT           SCHED_FIXEDPOINT_SHIFT
 407 # define SCHED_CAPACITY_SCALE           (1L << SCHED_CAPACITY_SHIFT)
 408
 409 struct load_weight {
 410         unsigned long                   weight;
 411         u32                             inv_weight;
 412 };
 413
 414 /**
 415  * struct util_est - Estimation utilization of FAIR tasks
 416  * @enqueued: instantaneous estimated utilization of a task/cpu
 417  * @ewma:     the Exponential Weighted Moving Average (EWMA)
 418  *            utilization of a task
 419  *
 420  * Support data structure to track an Exponential Weighted Moving Average
 421  * (EWMA) of a FAIR task's utilization. New samples are added to the moving
 422  * average each time a task completes an activation. Sample's weight is chosen
 423  * so that the EWMA will be relatively insensitive to transient changes to the
 424  * task's workload.
 425  *
 426  * The enqueued attribute has a slightly different meaning for tasks and cpus:
 427  * - task:   the task's util_avg at last task dequeue time
 428  * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU
 429  * Thus, the util_est.enqueued of a task represents the contribution on the
 430  * estimated utilization of the CPU where that task is currently enqueued.
 431  *
 432  * Only for tasks we track a moving average of the past instantaneous
 433  * estimated utilization. This allows to absorb sporadic drops in utilization
 434  * of an otherwise almost periodic task.
 435  *
 436  * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg
 437  * updates. When a task is dequeued, its util_est should not be updated if its
 438  * util_avg has not been updated in the meantime.
 439  * This information is mapped into the MSB bit of util_est.enqueued at dequeue
 440  * time. Since max value of util_est.enqueued for a task is 1024 (PELT util_avg
 441  * for a task) it is safe to use MSB.
 442  */
 443 struct util_est {
 444         unsigned int                    enqueued;
 445         unsigned int                    ewma;
 446 #define UTIL_EST_WEIGHT_SHIFT           2
 447 #define UTIL_AVG_UNCHANGED              0x80000000
 448 } __attribute__((__aligned__(sizeof(u64))));
 449
 450 /*
 451  * The load/runnable/util_avg accumulates an infinite geometric series
 452  * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c).
 453  *
 454  * [load_avg definition]
 455  *
 456  *   load_avg = runnable% * scale_load_down(load)
 457  *
 458  * [runnable_avg definition]
 459  *
 460  *   runnable_avg = runnable% * SCHED_CAPACITY_SCALE
 461  *
 462  * [util_avg definition]
 463  *
 464  *   util_avg = running% * SCHED_CAPACITY_SCALE
 465  *
 466  * where runnable% is the time ratio that a sched_entity is runnable and
 467  * running% the time ratio that a sched_entity is running.
 468  *
 469  * For cfs_rq, they are the aggregated values of all runnable and blocked
 470  * sched_entities.
 471  *
 472  * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU
 473  * capacity scaling. The scaling is done through the rq_clock_pelt that is used
 474  * for computing those signals (see update_rq_clock_pelt())
 475  *
 476  * N.B., the above ratios (runnable% and running%) themselves are in the
 477  * range of [0, 1]. To do fixed point arithmetics, we therefore scale them
 478  * to as large a range as necessary. This is for example reflected by
 479  * util_avg's SCHED_CAPACITY_SCALE.
 480  *
 481  * [Overflow issue]
 482  *
 483  * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
 484  * with the highest load (=88761), always runnable on a single cfs_rq,
 485  * and should not overflow as the number already hits PID_MAX_LIMIT.
 486  *
 487  * For all other cases (including 32-bit kernels), struct load_weight's
 488  * weight will overflow first before we do, because:
 489  *
 490  *    Max(load_avg) <= Max(load.weight)
 491  *
 492  * Then it is the load_weight's responsibility to consider overflow
 493  * issues.
 494  */
 495 struct sched_avg {
 496         u64                             last_update_time;
 497         u64                             load_sum;
 498         u64                             runnable_sum;
 499         u32                             util_sum;
 500         u32                             period_contrib;
 501         unsigned long                   load_avg;
 502         unsigned long                   runnable_avg;
 503         unsigned long                   util_avg;
 504         struct util_est                 util_est;
 505 } ____cacheline_aligned;
 506
 507 struct sched_statistics {
 508 #ifdef CONFIG_SCHEDSTATS
 509         u64                             wait_start;
 510         u64                             wait_max;
 511         u64                             wait_count;
 512         u64                             wait_sum;
 513         u64                             iowait_count;
 514         u64                             iowait_sum;
 515
 516         u64                             sleep_start;
 517         u64                             sleep_max;
 518         s64                             sum_sleep_runtime;
 519
 520         u64                             block_start;
 521         u64                             block_max;
 522         s64                             sum_block_runtime;
 523
 524         u64                             exec_max;
 525         u64                             slice_max;
 526
 527         u64                             nr_migrations_cold;
 528         u64                             nr_failed_migrations_affine;
 529         u64                             nr_failed_migrations_running;
 530         u64                             nr_failed_migrations_hot;
 531         u64                             nr_forced_migrations;
 532
 533         u64                             nr_wakeups;
 534         u64                             nr_wakeups_sync;
 535         u64                             nr_wakeups_migrate;
 536         u64                             nr_wakeups_local;
 537         u64                             nr_wakeups_remote;
 538         u64                             nr_wakeups_affine;
 539         u64                             nr_wakeups_affine_attempts;
 540         u64                             nr_wakeups_passive;
 541         u64                             nr_wakeups_idle;
 542
 543 #ifdef CONFIG_SCHED_CORE
 544         u64                             core_forceidle_sum;
 545 #endif
 546 #endif /* CONFIG_SCHEDSTATS */
 547 } ____cacheline_aligned;
 548
 549 struct sched_entity {
 550         /* For load-balancing: */
 551         struct load_weight              load;
 552         struct rb_node                  run_node;
 553         struct list_head                group_node;
 554         unsigned int                    on_rq;
 555
 556         u64                             exec_start;
 557         u64                             sum_exec_runtime;
 558         u64                             vruntime;
 559         u64                             prev_sum_exec_runtime;
 560
 561         u64                             nr_migrations;
 562
 563 #ifdef CONFIG_FAIR_GROUP_SCHED
 564         int                             depth;
 565         struct sched_entity             *parent;
 566         /* rq on which this entity is (to be) queued: */
 567         struct cfs_rq                   *cfs_rq;
 568         /* rq "owned" by this entity/group: */
 569         struct cfs_rq                   *my_q;
 570         /* cached value of my_q->h_nr_running */
 571         unsigned long                   runnable_weight;
 572 #endif
 573
 574 #ifdef CONFIG_SMP
 575         /*
 576          * Per entity load average tracking.
 577          *
 578          * Put into separate cache line so it does not
 579          * collide with read-mostly values above.
 580          */
 581         struct sched_avg                avg;
 582 #endif
 583 };
 584
 585 struct sched_rt_entity {
 586         struct list_head                run_list;
 587         unsigned long                   timeout;
 588         unsigned long                   watchdog_stamp;
 589         unsigned int                    time_slice;
 590         unsigned short                  on_rq;
 591         unsigned short                  on_list;
 592
 593         struct sched_rt_entity          *back;
 594 #ifdef CONFIG_RT_GROUP_SCHED
 595         struct sched_rt_entity          *parent;
 596         /* rq on which this entity is (to be) queued: */
 597         struct rt_rq                    *rt_rq;
 598         /* rq "owned" by this entity/group: */
 599         struct rt_rq                    *my_q;
 600 #endif
 601 } __randomize_layout;
 602
 603 struct sched_dl_entity {
 604         struct rb_node                  rb_node;
 605
 606         /*
 607          * Original scheduling parameters. Copied here from sched_attr
 608          * during sched_setattr(), they will remain the same until
 609          * the next sched_setattr().
 610          */
 611         u64                             dl_runtime;     /* Maximum runtime for each instance    */
 612         u64                             dl_deadline;    /* Relative deadline of each instance   */
 613         u64                             dl_period;      /* Separation of two instances (period) */
 614         u64                             dl_bw;          /* dl_runtime / dl_period               */
 615         u64                             dl_density;     /* dl_runtime / dl_deadline             */
 616
 617         /*
 618          * Actual scheduling parameters. Initialized with the values above,
 619          * they are continuously updated during task execution. Note that
 620          * the remaining runtime could be < 0 in case we are in overrun.
 621          */
 622         s64                             runtime;        /* Remaining runtime for this instance  */
 623         u64                             deadline;       /* Absolute deadline for this instance  */
 624         unsigned int                    flags;          /* Specifying the scheduler behaviour   */
 625
 626         /*
 627          * Some bool flags:
 628          *
 629          * @dl_throttled tells if we exhausted the runtime. If so, the
 630          * task has to wait for a replenishment to be performed at the
 631          * next firing of dl_timer.
 632          *
 633          * @dl_yielded tells if task gave up the CPU before consuming
 634          * all its available runtime during the last job.
 635          *
 636          * @dl_non_contending tells if the task is inactive while still
 637          * contributing to the active utilization. In other words, it
 638          * indicates if the inactive timer has been armed and its handler
 639          * has not been executed yet. This flag is useful to avoid race
 640          * conditions between the inactive timer handler and the wakeup
 641          * code.
 642          *
 643          * @dl_overrun tells if the task asked to be informed about runtime
 644          * overruns.
 645          */
 646         unsigned int                    dl_throttled      : 1;
 647         unsigned int                    dl_yielded        : 1;
 648         unsigned int                    dl_non_contending : 1;
 649         unsigned int                    dl_overrun        : 1;
 650
 651         /*
 652          * Bandwidth enforcement timer. Each -deadline task has its
 653          * own bandwidth to be enforced, thus we need one timer per task.
 654          */
 655         struct hrtimer                  dl_timer;
 656
 657         /*
 658          * Inactive timer, responsible for decreasing the active utilization
 659          * at the "0-lag time". When a -deadline task blocks, it contributes
 660          * to GRUB's active utilization until the "0-lag time", hence a
 661          * timer is needed to decrease the active utilization at the correct
 662          * time.
 663          */
 664         struct hrtimer inactive_timer;
 665
 666 #ifdef CONFIG_RT_MUTEXES
 667         /*
 668          * Priority Inheritance. When a DEADLINE scheduling entity is boosted
 669          * pi_se points to the donor, otherwise points to the dl_se it belongs
 670          * to (the original one/itself).
 671          */
 672         struct sched_dl_entity *pi_se;
 673 #endif
 674 };
 675
 676 #ifdef CONFIG_UCLAMP_TASK
 677 /* Number of utilization clamp buckets (shorter alias) */
 678 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT
 679
 680 /*
 681  * Utilization clamp for a scheduling entity
 682  * @value:              clamp value "assigned" to a se
 683  * @bucket_id:          bucket index corresponding to the "assigned" value
 684  * @active:             the se is currently refcounted in a rq's bucket
 685  * @user_defined:       the requested clamp value comes from user-space
 686  *
 687  * The bucket_id is the index of the clamp bucket matching the clamp value
 688  * which is pre-computed and stored to avoid expensive integer divisions from
 689  * the fast path.
 690  *
 691  * The active bit is set whenever a task has got an "effective" value assigned,
 692  * which can be different from the clamp value "requested" from user-space.
 693  * This allows to know a task is refcounted in the rq's bucket corresponding
 694  * to the "effective" bucket_id.
 695  *
 696  * The user_defined bit is set whenever a task has got a task-specific clamp
 697  * value requested from userspace, i.e. the system defaults apply to this task
 698  * just as a restriction. This allows to relax default clamps when a less
 699  * restrictive task-specific value has been requested, thus allowing to
 700  * implement a "nice" semantic. For example, a task running with a 20%
 701  * default boost can still drop its own boosting to 0%.
 702  */
 703 struct uclamp_se {
 704         unsigned int value              : bits_per(SCHED_CAPACITY_SCALE);
 705         unsigned int bucket_id          : bits_per(UCLAMP_BUCKETS);
 706         unsigned int active             : 1;
 707         unsigned int user_defined       : 1;
 708 };
 709 #endif /* CONFIG_UCLAMP_TASK */
 710
 711 union rcu_special {
 712         struct {
 713                 u8                      blocked;
 714                 u8                      need_qs;
 715                 u8                      exp_hint; /* Hint for performance. */
 716                 u8                      need_mb; /* Readers need smp_mb(). */
 717         } b; /* Bits. */
 718         u32 s; /* Set of bits. */
 719 };
 720
 721 enum perf_event_task_context {
 722         perf_invalid_context = -1,
 723         perf_hw_context = 0,
 724         perf_sw_context,
 725         perf_nr_task_contexts,
 726 };
 727
 728 struct wake_q_node {
 729         struct wake_q_node *next;
 730 };
 731
 732 struct kmap_ctrl {
 733 #ifdef CONFIG_KMAP_LOCAL
 734         int                             idx;
 735         pte_t                           pteval[KM_MAX_IDX];
 736 #endif
 737 };
 738
 739 struct task_struct {
 740 #ifdef CONFIG_THREAD_INFO_IN_TASK
 741         /*
 742          * For reasons of header soup (see current_thread_info()), this
 743          * must be the first element of task_struct.
 744          */
 745         struct thread_info              thread_info;
 746 #endif
 747         unsigned int                    __state;
 748
 749 #ifdef CONFIG_PREEMPT_RT
 750         /* saved state for "spinlock sleepers" */
 751         unsigned int                    saved_state;
 752 #endif
 753
 754         /*
 755          * This begins the randomizable portion of task_struct. Only
 756          * scheduling-critical items should be added above here.
 757          */
 758         randomized_struct_fields_start
 759
 760         void                            *stack;
 761         refcount_t                      usage;
 762         /* Per task flags (PF_*), defined further below: */
 763         unsigned int                    flags;
 764         unsigned int                    ptrace;
 765
 766 #ifdef CONFIG_SMP
 767         int                             on_cpu;
 768         struct __call_single_node       wake_entry;
 769         unsigned int                    wakee_flips;
 770         unsigned long                   wakee_flip_decay_ts;
 771         struct task_struct              *last_wakee;
 772
 773         /*
 774          * recent_used_cpu is initially set as the last CPU used by a task
 775          * that wakes affine another task. Waker/wakee relationships can
 776          * push tasks around a CPU where each wakeup moves to the next one.
 777          * Tracking a recently used CPU allows a quick search for a recently
 778          * used CPU that may be idle.
 779          */
 780         int                             recent_used_cpu;
 781         int                             wake_cpu;
 782 #endif
 783         int                             on_rq;
 784
 785         int                             prio;
 786         int                             static_prio;
 787         int                             normal_prio;
 788         unsigned int                    rt_priority;
 789
 790         struct sched_entity             se;
 791         struct sched_rt_entity          rt;
 792         struct sched_dl_entity          dl;
 793         const struct sched_class        *sched_class;
 794
 795 #ifdef CONFIG_SCHED_CORE
 796         struct rb_node                  core_node;
 797         unsigned long                   core_cookie;
 798         unsigned int                    core_occupation;
 799 #endif
 800
 801 #ifdef CONFIG_CGROUP_SCHED
 802         struct task_group               *sched_task_group;
 803 #endif
 804
 805 #ifdef CONFIG_UCLAMP_TASK
 806         /*
 807          * Clamp values requested for a scheduling entity.
 808          * Must be updated with task_rq_lock() held.
 809          */
 810         struct uclamp_se                uclamp_req[UCLAMP_CNT];
 811         /*
 812          * Effective clamp values used for a scheduling entity.
 813          * Must be updated with task_rq_lock() held.
 814          */
 815         struct uclamp_se                uclamp[UCLAMP_CNT];
 816 #endif
 817
 818         struct sched_statistics         stats;
 819
 820 #ifdef CONFIG_PREEMPT_NOTIFIERS
 821         /* List of struct preempt_notifier: */
 822         struct hlist_head               preempt_notifiers;
 823 #endif
 824
 825 #ifdef CONFIG_BLK_DEV_IO_TRACE
 826         unsigned int                    btrace_seq;
 827 #endif
 828
 829         unsigned int                    policy;
 830         int                             nr_cpus_allowed;
 831         const cpumask_t                 *cpus_ptr;
 832         cpumask_t                       *user_cpus_ptr;
 833         cpumask_t                       cpus_mask;
 834         void                            *migration_pending;
 835 #ifdef CONFIG_SMP
 836         unsigned short                  migration_disabled;
 837 #endif
 838         unsigned short                  migration_flags;
 839
 840 #ifdef CONFIG_PREEMPT_RCU
 841         int                             rcu_read_lock_nesting;
 842         union rcu_special               rcu_read_unlock_special;
 843         struct list_head                rcu_node_entry;
 844         struct rcu_node                 *rcu_blocked_node;
 845 #endif /* #ifdef CONFIG_PREEMPT_RCU */
 846
 847 #ifdef CONFIG_TASKS_RCU
 848         unsigned long                   rcu_tasks_nvcsw;
 849         u8                              rcu_tasks_holdout;
 850         u8                              rcu_tasks_idx;
 851         int                             rcu_tasks_idle_cpu;
 852         struct list_head                rcu_tasks_holdout_list;
 853 #endif /* #ifdef CONFIG_TASKS_RCU */
 854
 855 #ifdef CONFIG_TASKS_TRACE_RCU
 856         int                             trc_reader_nesting;
 857         int                             trc_ipi_to_cpu;
 858         union rcu_special               trc_reader_special;
 859         struct list_head                trc_holdout_list;
 860         struct list_head                trc_blkd_node;
 861         int                             trc_blkd_cpu;
 862 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
 863
 864         struct sched_info               sched_info;
 865
 866         struct list_head                tasks;
 867 #ifdef CONFIG_SMP
 868         struct plist_node               pushable_tasks;
 869         struct rb_node                  pushable_dl_tasks;
 870 #endif
 871
 872         struct mm_struct                *mm;
 873         struct mm_struct                *active_mm;
 874
 875         int                             exit_state;
 876         int                             exit_code;
 877         int                             exit_signal;
 878         /* The signal sent when the parent dies: */
 879         int                             pdeath_signal;
 880         /* JOBCTL_*, siglock protected: */
 881         unsigned long                   jobctl;
 882
 883         /* Used for emulating ABI behavior of previous Linux versions: */
 884         unsigned int                    personality;
 885
 886         /* Scheduler bits, serialized by scheduler locks: */
 887         unsigned                        sched_reset_on_fork:1;
 888         unsigned                        sched_contributes_to_load:1;
 889         unsigned                        sched_migrated:1;
 890
 891         /* Force alignment to the next boundary: */
 892         unsigned                        :0;
 893
 894         /* Unserialized, strictly 'current' */
 895
 896         /*
 897          * This field must not be in the scheduler word above due to wakelist
 898          * queueing no longer being serialized by p->on_cpu. However:
 899          *
 900          * p->XXX = X;                  ttwu()
 901          * schedule()                     if (p->on_rq && ..) // false
 902          *   smp_mb__after_spinlock();    if (smp_load_acquire(&p->on_cpu) && //true
 903          *   deactivate_task()                ttwu_queue_wakelist())
 904          *     p->on_rq = 0;                    p->sched_remote_wakeup = Y;
 905          *
 906          * guarantees all stores of 'current' are visible before
 907          * ->sched_remote_wakeup gets used, so it can be in this word.
 908          */
 909         unsigned                        sched_remote_wakeup:1;
 910
 911         /* Bit to tell LSMs we're in execve(): */
 912         unsigned                        in_execve:1;
 913         unsigned                        in_iowait:1;
 914 #ifndef TIF_RESTORE_SIGMASK
 915         unsigned                        restore_sigmask:1;
 916 #endif
 917 #ifdef CONFIG_MEMCG
 918         unsigned                        in_user_fault:1;
 919 #endif
 920 #ifdef CONFIG_LRU_GEN
 921         /* whether the LRU algorithm may apply to this access */
 922         unsigned                        in_lru_fault:1;
 923 #endif
 924 #ifdef CONFIG_COMPAT_BRK
 925         unsigned                        brk_randomized:1;
 926 #endif
 927 #ifdef CONFIG_CGROUPS
 928         /* disallow userland-initiated cgroup migration */
 929         unsigned                        no_cgroup_migration:1;
 930         /* task is frozen/stopped (used by the cgroup freezer) */
 931         unsigned                        frozen:1;
 932 #endif
 933 #ifdef CONFIG_BLK_CGROUP
 934         unsigned                        use_memdelay:1;
 935 #endif
 936 #ifdef CONFIG_PSI
 937         /* Stalled due to lack of memory */
 938         unsigned                        in_memstall:1;
 939 #endif
 940 #ifdef CONFIG_PAGE_OWNER
 941         /* Used by page_owner=on to detect recursion in page tracking. */
 942         unsigned                        in_page_owner:1;
 943 #endif
 944 #ifdef CONFIG_EVENTFD
 945         /* Recursion prevention for eventfd_signal() */
 946         unsigned                        in_eventfd:1;
 947 #endif
 948 #ifdef CONFIG_IOMMU_SVA
 949         unsigned                        pasid_activated:1;
 950 #endif
 951 #ifdef  CONFIG_CPU_SUP_INTEL
 952         unsigned                        reported_split_lock:1;
 953 #endif
 954 #ifdef CONFIG_TASK_DELAY_ACCT
 955         /* delay due to memory thrashing */
 956         unsigned                        in_thrashing:1;
 957 #endif
 958
 959         unsigned long                   atomic_flags; /* Flags requiring atomic access. */
 960
 961         struct restart_block            restart_block;
 962
 963         pid_t                           pid;
 964         pid_t                           tgid;
 965
 966 #ifdef CONFIG_STACKPROTECTOR
 967         /* Canary value for the -fstack-protector GCC feature: */
 968         unsigned long                   stack_canary;
 969 #endif
 970         /*
 971          * Pointers to the (original) parent process, youngest child, younger sibling,
 972          * older sibling, respectively.  (p->father can be replaced with
 973          * p->real_parent->pid)
 974          */
 975
 976         /* Real parent process: */
 977         struct task_struct __rcu        *real_parent;
 978
 979         /* Recipient of SIGCHLD, wait4() reports: */
 980         struct task_struct __rcu        *parent;
 981
 982         /*
 983          * Children/sibling form the list of natural children:
 984          */
 985         struct list_head                children;
 986         struct list_head                sibling;
 987         struct task_struct              *group_leader;
 988
 989         /*
 990          * 'ptraced' is the list of tasks this task is using ptrace() on.
 991          *
 992          * This includes both natural children and PTRACE_ATTACH targets.
 993          * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
 994          */
 995         struct list_head                ptraced;
 996         struct list_head                ptrace_entry;
 997
 998         /* PID/PID hash table linkage. */
 999         struct pid                      *thread_pid;
1000         struct hlist_node               pid_links[PIDTYPE_MAX];
1001         struct list_head                thread_group;
1002         struct list_head                thread_node;
1003
1004         struct completion               *vfork_done;
1005
1006         /* CLONE_CHILD_SETTID: */
1007         int __user                      *set_child_tid;
1008
1009         /* CLONE_CHILD_CLEARTID: */
1010         int __user                      *clear_child_tid;
1011
1012         /* PF_KTHREAD | PF_IO_WORKER */
1013         void                            *worker_private;
1014
1015         u64                             utime;
1016         u64                             stime;
1017 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
1018         u64                             utimescaled;
1019         u64                             stimescaled;
1020 #endif
1021         u64                             gtime;
1022         struct prev_cputime             prev_cputime;
1023 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1024         struct vtime                    vtime;
1025 #endif
1026
1027 #ifdef CONFIG_NO_HZ_FULL
1028         atomic_t                        tick_dep_mask;
1029 #endif
1030         /* Context switch counts: */
1031         unsigned long                   nvcsw;
1032         unsigned long                   nivcsw;
1033
1034         /* Monotonic time in nsecs: */
1035         u64                             start_time;
1036
1037         /* Boot based time in nsecs: */
1038         u64                             start_boottime;
1039
1040         /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
1041         unsigned long                   min_flt;
1042         unsigned long                   maj_flt;
1043
1044         /* Empty if CONFIG_POSIX_CPUTIMERS=n */
1045         struct posix_cputimers          posix_cputimers;
1046
1047 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK
1048         struct posix_cputimers_work     posix_cputimers_work;
1049 #endif
1050
1051         /* Process credentials: */
1052
1053         /* Tracer's credentials at attach: */
1054         const struct cred __rcu         *ptracer_cred;
1055
1056         /* Objective and real subjective task credentials (COW): */
1057         const struct cred __rcu         *real_cred;
1058
1059         /* Effective (overridable) subjective task credentials (COW): */
1060         const struct cred __rcu         *cred;
1061
1062 #ifdef CONFIG_KEYS
1063         /* Cached requested key. */
1064         struct key                      *cached_requested_key;
1065 #endif
1066
1067         /*
1068          * executable name, excluding path.
1069          *
1070          * - normally initialized setup_new_exec()
1071          * - access it with [gs]et_task_comm()
1072          * - lock it with task_lock()
1073          */
1074         char                            comm[TASK_COMM_LEN];
1075
1076         struct nameidata                *nameidata;
1077
1078 #ifdef CONFIG_SYSVIPC
1079         struct sysv_sem                 sysvsem;
1080         struct sysv_shm                 sysvshm;
1081 #endif
1082 #ifdef CONFIG_DETECT_HUNG_TASK
1083         unsigned long                   last_switch_count;
1084         unsigned long                   last_switch_time;
1085 #endif
1086         /* Filesystem information: */
1087         struct fs_struct                *fs;
1088
1089         /* Open file information: */
1090         struct files_struct             *files;
1091
1092 #ifdef CONFIG_IO_URING
1093         struct io_uring_task            *io_uring;
1094 #endif
1095
1096         /* Namespaces: */
1097         struct nsproxy                  *nsproxy;
1098
1099         /* Signal handlers: */
1100         struct signal_struct            *signal;
1101         struct sighand_struct __rcu             *sighand;
1102         sigset_t                        blocked;
1103         sigset_t                        real_blocked;
1104         /* Restored if set_restore_sigmask() was used: */
1105         sigset_t                        saved_sigmask;
1106         struct sigpending               pending;
1107         unsigned long                   sas_ss_sp;
1108         size_t                          sas_ss_size;
1109         unsigned int                    sas_ss_flags;
1110
1111         struct callback_head            *task_works;
1112
1113 #ifdef CONFIG_AUDIT
1114 #ifdef CONFIG_AUDITSYSCALL
1115         struct audit_context            *audit_context;
1116 #endif
1117         kuid_t                          loginuid;
1118         unsigned int                    sessionid;
1119 #endif
1120         struct seccomp                  seccomp;
1121         struct syscall_user_dispatch    syscall_dispatch;
1122
1123         /* Thread group tracking: */
1124         u64                             parent_exec_id;
1125         u64                             self_exec_id;
1126
1127         /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
1128         spinlock_t                      alloc_lock;
1129
1130         /* Protection of the PI data structures: */
1131         raw_spinlock_t                  pi_lock;
1132
1133         struct wake_q_node              wake_q;
1134
1135 #ifdef CONFIG_RT_MUTEXES
1136         /* PI waiters blocked on a rt_mutex held by this task: */
1137         struct rb_root_cached           pi_waiters;
1138         /* Updated under owner's pi_lock and rq lock */
1139         struct task_struct              *pi_top_task;
1140         /* Deadlock detection and priority inheritance handling: */
1141         struct rt_mutex_waiter          *pi_blocked_on;
1142 #endif
1143
1144 #ifdef CONFIG_DEBUG_MUTEXES
1145         /* Mutex deadlock detection: */
1146         struct mutex_waiter             *blocked_on;
1147 #endif
1148
1149 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1150         int                             non_block_count;
1151 #endif
1152
1153 #ifdef CONFIG_TRACE_IRQFLAGS
1154         struct irqtrace_events          irqtrace;
1155         unsigned int                    hardirq_threaded;
1156         u64                             hardirq_chain_key;
1157         int                             softirqs_enabled;
1158         int                             softirq_context;
1159         int                             irq_config;
1160 #endif
1161 #ifdef CONFIG_PREEMPT_RT
1162         int                             softirq_disable_cnt;
1163 #endif
1164
1165 #ifdef CONFIG_LOCKDEP
1166 # define MAX_LOCK_DEPTH                 48UL
1167         u64                             curr_chain_key;
1168         int                             lockdep_depth;
1169         unsigned int                    lockdep_recursion;
1170         struct held_lock                held_locks[MAX_LOCK_DEPTH];
1171 #endif
1172
1173 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP)
1174         unsigned int                    in_ubsan;
1175 #endif
1176
1177         /* Journalling filesystem info: */
1178         void                            *journal_info;
1179
1180         /* Stacked block device info: */
1181         struct bio_list                 *bio_list;
1182
1183         /* Stack plugging: */
1184         struct blk_plug                 *plug;
1185
1186         /* VM state: */
1187         struct reclaim_state            *reclaim_state;
1188
1189         struct backing_dev_info         *backing_dev_info;
1190
1191         struct io_context               *io_context;
1192
1193 #ifdef CONFIG_COMPACTION
1194         struct capture_control          *capture_control;
1195 #endif
1196         /* Ptrace state: */
1197         unsigned long                   ptrace_message;
1198         kernel_siginfo_t                *last_siginfo;
1199
1200         struct task_io_accounting       ioac;
1201 #ifdef CONFIG_PSI
1202         /* Pressure stall state */
1203         unsigned int                    psi_flags;
1204 #endif
1205 #ifdef CONFIG_TASK_XACCT
1206         /* Accumulated RSS usage: */
1207         u64                             acct_rss_mem1;
1208         /* Accumulated virtual memory usage: */
1209         u64                             acct_vm_mem1;
1210         /* stime + utime since last update: */
1211         u64                             acct_timexpd;
1212 #endif
1213 #ifdef CONFIG_CPUSETS
1214         /* Protected by ->alloc_lock: */
1215         nodemask_t                      mems_allowed;
1216         /* Sequence number to catch updates: */
1217         seqcount_spinlock_t             mems_allowed_seq;
1218         int                             cpuset_mem_spread_rotor;
1219         int                             cpuset_slab_spread_rotor;
1220 #endif
1221 #ifdef CONFIG_CGROUPS
1222         /* Control Group info protected by css_set_lock: */
1223         struct css_set __rcu            *cgroups;
1224         /* cg_list protected by css_set_lock and tsk->alloc_lock: */
1225         struct list_head                cg_list;
1226 #endif
1227 #ifdef CONFIG_X86_CPU_RESCTRL
1228         u32                             closid;
1229         u32                             rmid;
1230 #endif
1231 #ifdef CONFIG_FUTEX
1232         struct robust_list_head __user  *robust_list;
1233 #ifdef CONFIG_COMPAT
1234         struct compat_robust_list_head __user *compat_robust_list;
1235 #endif
1236         struct list_head                pi_state_list;
1237         struct futex_pi_state           *pi_state_cache;
1238         struct mutex                    futex_exit_mutex;
1239         unsigned int                    futex_state;
1240 #endif
1241 #ifdef CONFIG_PERF_EVENTS
1242         struct perf_event_context       *perf_event_ctxp;
1243         struct mutex                    perf_event_mutex;
1244         struct list_head                perf_event_list;
1245 #endif
1246 #ifdef CONFIG_DEBUG_PREEMPT
1247         unsigned long                   preempt_disable_ip;
1248 #endif
1249 #ifdef CONFIG_NUMA
1250         /* Protected by alloc_lock: */
1251         struct mempolicy                *mempolicy;
1252         short                           il_prev;
1253         short                           pref_node_fork;
1254 #endif
1255 #ifdef CONFIG_NUMA_BALANCING
1256         int                             numa_scan_seq;
1257         unsigned int                    numa_scan_period;
1258         unsigned int                    numa_scan_period_max;
1259         int                             numa_preferred_nid;
1260         unsigned long                   numa_migrate_retry;
1261         /* Migration stamp: */
1262         u64                             node_stamp;
1263         u64                             last_task_numa_placement;
1264         u64                             last_sum_exec_runtime;
1265         struct callback_head            numa_work;
1266
1267         /*
1268          * This pointer is only modified for current in syscall and
1269          * pagefault context (and for tasks being destroyed), so it can be read
1270          * from any of the following contexts:
1271          *  - RCU read-side critical section
1272          *  - current->numa_group from everywhere
1273          *  - task's runqueue locked, task not running
1274          */
1275         struct numa_group __rcu         *numa_group;
1276
1277         /*
1278          * numa_faults is an array split into four regions:
1279          * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1280          * in this precise order.
1281          *
1282          * faults_memory: Exponential decaying average of faults on a per-node
1283          * basis. Scheduling placement decisions are made based on these
1284          * counts. The values remain static for the duration of a PTE scan.
1285          * faults_cpu: Track the nodes the process was running on when a NUMA
1286          * hinting fault was incurred.
1287          * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1288          * during the current scan window. When the scan completes, the counts
1289          * in faults_memory and faults_cpu decay and these values are copied.
1290          */
1291         unsigned long                   *numa_faults;
1292         unsigned long                   total_numa_faults;
1293
1294         /*
1295          * numa_faults_locality tracks if faults recorded during the last
1296          * scan window were remote/local or failed to migrate. The task scan
1297          * period is adapted based on the locality of the faults with different
1298          * weights depending on whether they were shared or private faults
1299          */
1300         unsigned long                   numa_faults_locality[3];
1301
1302         unsigned long                   numa_pages_migrated;
1303 #endif /* CONFIG_NUMA_BALANCING */
1304
1305 #ifdef CONFIG_RSEQ
1306         struct rseq __user *rseq;
1307         u32 rseq_len;
1308         u32 rseq_sig;
1309         /*
1310          * RmW on rseq_event_mask must be performed atomically
1311          * with respect to preemption.
1312          */
1313         unsigned long rseq_event_mask;
1314 #endif
1315
1316 #ifdef CONFIG_SCHED_MM_CID
1317         int                             mm_cid;         /* Current cid in mm */
1318         int                             last_mm_cid;    /* Most recent cid in mm */
1319         int                             migrate_from_cpu;
1320         int                             mm_cid_active;  /* Whether cid bitmap is active */
1321         struct callback_head            cid_work;
1322 #endif
1323
1324         struct tlbflush_unmap_batch     tlb_ubc;
1325
1326         /* Cache last used pipe for splice(): */
1327         struct pipe_inode_info          *splice_pipe;
1328
1329         struct page_frag                task_frag;
1330
1331 #ifdef CONFIG_TASK_DELAY_ACCT
1332         struct task_delay_info          *delays;
1333 #endif
1334
1335 #ifdef CONFIG_FAULT_INJECTION
1336         int                             make_it_fail;
1337         unsigned int                    fail_nth;
1338 #endif
1339         /*
1340          * When (nr_dirtied >= nr_dirtied_pause), it's time to call
1341          * balance_dirty_pages() for a dirty throttling pause:
1342          */
1343         int                             nr_dirtied;
1344         int                             nr_dirtied_pause;
1345         /* Start of a write-and-pause period: */
1346         unsigned long                   dirty_paused_when;
1347
1348 #ifdef CONFIG_LATENCYTOP
1349         int                             latency_record_count;
1350         struct latency_record           latency_record[LT_SAVECOUNT];
1351 #endif
1352         /*
1353          * Time slack values; these are used to round up poll() and
1354          * select() etc timeout values. These are in nanoseconds.
1355          */
1356         u64                             timer_slack_ns;
1357         u64                             default_timer_slack_ns;
1358
1359 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
1360         unsigned int                    kasan_depth;
1361 #endif
1362
1363 #ifdef CONFIG_KCSAN
1364         struct kcsan_ctx                kcsan_ctx;
1365 #ifdef CONFIG_TRACE_IRQFLAGS
1366         struct irqtrace_events          kcsan_save_irqtrace;
1367 #endif
1368 #ifdef CONFIG_KCSAN_WEAK_MEMORY
1369         int                             kcsan_stack_depth;
1370 #endif
1371 #endif
1372
1373 #ifdef CONFIG_KMSAN
1374         struct kmsan_ctx                kmsan_ctx;
1375 #endif
1376
1377 #if IS_ENABLED(CONFIG_KUNIT)
1378         struct kunit                    *kunit_test;
1379 #endif
1380
1381 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1382         /* Index of current stored address in ret_stack: */
1383         int                             curr_ret_stack;
1384         int                             curr_ret_depth;
1385
1386         /* Stack of return addresses for return function tracing: */
1387         struct ftrace_ret_stack         *ret_stack;
1388
1389         /* Timestamp for last schedule: */
1390         unsigned long long              ftrace_timestamp;
1391
1392         /*
1393          * Number of functions that haven't been traced
1394          * because of depth overrun:
1395          */
1396         atomic_t                        trace_overrun;
1397
1398         /* Pause tracing: */
1399         atomic_t                        tracing_graph_pause;
1400 #endif
1401
1402 #ifdef CONFIG_TRACING
1403         /* Bitmask and counter of trace recursion: */
1404         unsigned long                   trace_recursion;
1405 #endif /* CONFIG_TRACING */
1406
1407 #ifdef CONFIG_KCOV
1408         /* See kernel/kcov.c for more details. */
1409
1410         /* Coverage collection mode enabled for this task (0 if disabled): */
1411         unsigned int                    kcov_mode;
1412
1413         /* Size of the kcov_area: */
1414         unsigned int                    kcov_size;
1415
1416         /* Buffer for coverage collection: */
1417         void                            *kcov_area;
1418
1419         /* KCOV descriptor wired with this task or NULL: */
1420         struct kcov                     *kcov;
1421
1422         /* KCOV common handle for remote coverage collection: */
1423         u64                             kcov_handle;
1424
1425         /* KCOV sequence number: */
1426         int                             kcov_sequence;
1427
1428         /* Collect coverage from softirq context: */
1429         unsigned int                    kcov_softirq;
1430 #endif
1431
1432 #ifdef CONFIG_MEMCG
1433         struct mem_cgroup               *memcg_in_oom;
1434         gfp_t                           memcg_oom_gfp_mask;
1435         int                             memcg_oom_order;
1436
1437         /* Number of pages to reclaim on returning to userland: */
1438         unsigned int                    memcg_nr_pages_over_high;
1439
1440         /* Used by memcontrol for targeted memcg charge: */
1441         struct mem_cgroup               *active_memcg;
1442 #endif
1443
1444 #ifdef CONFIG_BLK_CGROUP
1445         struct gendisk                  *throttle_disk;
1446 #endif
1447
1448 #ifdef CONFIG_UPROBES
1449         struct uprobe_task              *utask;
1450 #endif
1451 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1452         unsigned int                    sequential_io;
1453         unsigned int                    sequential_io_avg;
1454 #endif
1455         struct kmap_ctrl                kmap_ctrl;
1456 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1457         unsigned long                   task_state_change;
1458 # ifdef CONFIG_PREEMPT_RT
1459         unsigned long                   saved_state_change;
1460 # endif
1461 #endif
1462         struct rcu_head                 rcu;
1463         refcount_t                      rcu_users;
1464         int                             pagefault_disabled;
1465 #ifdef CONFIG_MMU
1466         struct task_struct              *oom_reaper_list;
1467         struct timer_list               oom_reaper_timer;
1468 #endif
1469 #ifdef CONFIG_VMAP_STACK
1470         struct vm_struct                *stack_vm_area;
1471 #endif
1472 #ifdef CONFIG_THREAD_INFO_IN_TASK
1473         /* A live task holds one reference: */
1474         refcount_t                      stack_refcount;
1475 #endif
1476 #ifdef CONFIG_LIVEPATCH
1477         int patch_state;
1478 #endif
1479 #ifdef CONFIG_SECURITY
1480         /* Used by LSM modules for access restriction: */
1481         void                            *security;
1482 #endif
1483 #ifdef CONFIG_BPF_SYSCALL
1484         /* Used by BPF task local storage */
1485         struct bpf_local_storage __rcu  *bpf_storage;
1486         /* Used for BPF run context */
1487         struct bpf_run_ctx              *bpf_ctx;
1488 #endif
1489
1490 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK
1491         unsigned long                   lowest_stack;
1492         unsigned long                   prev_lowest_stack;
1493 #endif
1494
1495 #ifdef CONFIG_X86_MCE
1496         void __user                     *mce_vaddr;
1497         __u64                           mce_kflags;
1498         u64                             mce_addr;
1499         __u64                           mce_ripv : 1,
1500                                         mce_whole_page : 1,
1501                                         __mce_reserved : 62;
1502         struct callback_head            mce_kill_me;
1503         int                             mce_count;
1504 #endif
1505
1506 #ifdef CONFIG_KRETPROBES
1507         struct llist_head               kretprobe_instances;
1508 #endif
1509 #ifdef CONFIG_RETHOOK
1510         struct llist_head               rethooks;
1511 #endif
1512
1513 #ifdef CONFIG_ARCH_HAS_PARANOID_L1D_FLUSH
1514         /*
1515          * If L1D flush is supported on mm context switch
1516          * then we use this callback head to queue kill work
1517          * to kill tasks that are not running on SMT disabled
1518          * cores
1519          */
1520         struct callback_head            l1d_flush_kill;
1521 #endif
1522
1523 #ifdef CONFIG_RV
1524         /*
1525          * Per-task RV monitor. Nowadays fixed in RV_PER_TASK_MONITORS.
1526          * If we find justification for more monitors, we can think
1527          * about adding more or developing a dynamic method. So far,
1528          * none of these are justified.
1529          */
1530         union rv_task_monitor           rv[RV_PER_TASK_MONITORS];
1531 #endif
1532
1533 #ifdef CONFIG_USER_EVENTS
1534         struct user_event_mm            *user_event_mm;
1535 #endif
1536
1537         /*
1538          * New fields for task_struct should be added above here, so that
1539          * they are included in the randomized portion of task_struct.
1540          */
1541         randomized_struct_fields_end
1542
1543         /* CPU-specific state of this task: */
1544         struct thread_struct            thread;
1545
1546         /*
1547          * WARNING: on x86, 'thread_struct' contains a variable-sized
1548          * structure.  It *MUST* be at the end of 'task_struct'.
1549          *
1550          * Do not put anything below here!
1551          */
1552 };
1553
1554 static inline struct pid *task_pid(struct task_struct *task)
1555 {
1556         return task->thread_pid;
1557 }
1558
1559 /*
1560  * the helpers to get the task's different pids as they are seen
1561  * from various namespaces
1562  *
1563  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1564  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1565  *                     current.
1566  * task_xid_nr_ns()  : id seen from the ns specified;
1567  *
1568  * see also pid_nr() etc in include/linux/pid.h
1569  */
1570 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns);
1571
1572 static inline pid_t task_pid_nr(struct task_struct *tsk)
1573 {
1574         return tsk->pid;
1575 }
1576
1577 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1578 {
1579         return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1580 }
1581
1582 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1583 {
1584         return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1585 }
1586
1587
1588 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1589 {
1590         return tsk->tgid;
1591 }
1592
1593 /**
1594  * pid_alive - check that a task structure is not stale
1595  * @p: Task structure to be checked.
1596  *
1597  * Test if a process is not yet dead (at most zombie state)
1598  * If pid_alive fails, then pointers within the task structure
1599  * can be stale and must not be dereferenced.
1600  *
1601  * Return: 1 if the process is alive. 0 otherwise.
1602  */
1603 static inline int pid_alive(const struct task_struct *p)
1604 {
1605         return p->thread_pid != NULL;
1606 }
1607
1608 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1609 {
1610         return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1611 }
1612
1613 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1614 {
1615         return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1616 }
1617
1618
1619 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1620 {
1621         return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1622 }
1623
1624 static inline pid_t task_session_vnr(struct task_struct *tsk)
1625 {
1626         return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1627 }
1628
1629 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1630 {
1631         return __task_pid_nr_ns(tsk, PIDTYPE_TGID, ns);
1632 }
1633
1634 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1635 {
1636         return __task_pid_nr_ns(tsk, PIDTYPE_TGID, NULL);
1637 }
1638
1639 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1640 {
1641         pid_t pid = 0;
1642
1643         rcu_read_lock();
1644         if (pid_alive(tsk))
1645                 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1646         rcu_read_unlock();
1647
1648         return pid;
1649 }
1650
1651 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1652 {
1653         return task_ppid_nr_ns(tsk, &init_pid_ns);
1654 }
1655
1656 /* Obsolete, do not use: */
1657 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1658 {
1659         return task_pgrp_nr_ns(tsk, &init_pid_ns);
1660 }
1661
1662 #define TASK_REPORT_IDLE        (TASK_REPORT + 1)
1663 #define TASK_REPORT_MAX         (TASK_REPORT_IDLE << 1)
1664
1665 static inline unsigned int __task_state_index(unsigned int tsk_state,
1666                                               unsigned int tsk_exit_state)
1667 {
1668         unsigned int state = (tsk_state | tsk_exit_state) & TASK_REPORT;
1669
1670         BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX);
1671
1672         if (tsk_state == TASK_IDLE)
1673                 state = TASK_REPORT_IDLE;
1674
1675         /*
1676          * We're lying here, but rather than expose a completely new task state
1677          * to userspace, we can make this appear as if the task has gone through
1678          * a regular rt_mutex_lock() call.
1679          */
1680         if (tsk_state == TASK_RTLOCK_WAIT)
1681                 state = TASK_UNINTERRUPTIBLE;
1682
1683         return fls(state);
1684 }
1685
1686 static inline unsigned int task_state_index(struct task_struct *tsk)
1687 {
1688         return __task_state_index(READ_ONCE(tsk->__state), tsk->exit_state);
1689 }
1690
1691 static inline char task_index_to_char(unsigned int state)
1692 {
1693         static const char state_char[] = "RSDTtXZPI";
1694
1695         BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1);
1696
1697         return state_char[state];
1698 }
1699
1700 static inline char task_state_to_char(struct task_struct *tsk)
1701 {
1702         return task_index_to_char(task_state_index(tsk));
1703 }
1704
1705 /**
1706  * is_global_init - check if a task structure is init. Since init
1707  * is free to have sub-threads we need to check tgid.
1708  * @tsk: Task structure to be checked.
1709  *
1710  * Check if a task structure is the first user space task the kernel created.
1711  *
1712  * Return: 1 if the task structure is init. 0 otherwise.
1713  */
1714 static inline int is_global_init(struct task_struct *tsk)
1715 {
1716         return task_tgid_nr(tsk) == 1;
1717 }
1718
1719 extern struct pid *cad_pid;
1720
1721 /*
1722  * Per process flags
1723  */
1724 #define PF_VCPU                 0x00000001      /* I'm a virtual CPU */
1725 #define PF_IDLE                 0x00000002      /* I am an IDLE thread */
1726 #define PF_EXITING              0x00000004      /* Getting shut down */
1727 #define PF_POSTCOREDUMP         0x00000008      /* Coredumps should ignore this task */
1728 #define PF_IO_WORKER            0x00000010      /* Task is an IO worker */
1729 #define PF_WQ_WORKER            0x00000020      /* I'm a workqueue worker */
1730 #define PF_FORKNOEXEC           0x00000040      /* Forked but didn't exec */
1731 #define PF_MCE_PROCESS          0x00000080      /* Process policy on mce errors */
1732 #define PF_SUPERPRIV            0x00000100      /* Used super-user privileges */
1733 #define PF_DUMPCORE             0x00000200      /* Dumped core */
1734 #define PF_SIGNALED             0x00000400      /* Killed by a signal */
1735 #define PF_MEMALLOC             0x00000800      /* Allocating memory */
1736 #define PF_NPROC_EXCEEDED       0x00001000      /* set_user() noticed that RLIMIT_NPROC was exceeded */
1737 #define PF_USED_MATH            0x00002000      /* If unset the fpu must be initialized before use */
1738 #define PF_USER_WORKER          0x00004000      /* Kernel thread cloned from userspace thread */
1739 #define PF_NOFREEZE             0x00008000      /* This thread should not be frozen */
1740 #define PF__HOLE__00010000      0x00010000
1741 #define PF_KSWAPD               0x00020000      /* I am kswapd */
1742 #define PF_MEMALLOC_NOFS        0x00040000      /* All allocation requests will inherit GFP_NOFS */
1743 #define PF_MEMALLOC_NOIO        0x00080000      /* All allocation requests will inherit GFP_NOIO */
1744 #define PF_LOCAL_THROTTLE       0x00100000      /* Throttle writes only against the bdi I write to,
1745                                                  * I am cleaning dirty pages from some other bdi. */
1746 #define PF_KTHREAD              0x00200000      /* I am a kernel thread */
1747 #define PF_RANDOMIZE            0x00400000      /* Randomize virtual address space */
1748 #define PF__HOLE__00800000      0x00800000
1749 #define PF__HOLE__01000000      0x01000000
1750 #define PF__HOLE__02000000      0x02000000
1751 #define PF_NO_SETAFFINITY       0x04000000      /* Userland is not allowed to meddle with cpus_mask */
1752 #define PF_MCE_EARLY            0x08000000      /* Early kill for mce process policy */
1753 #define PF_MEMALLOC_PIN         0x10000000      /* Allocation context constrained to zones which allow long term pinning. */
1754 #define PF__HOLE__20000000      0x20000000
1755 #define PF__HOLE__40000000      0x40000000
1756 #define PF_SUSPEND_TASK         0x80000000      /* This thread called freeze_processes() and should not be frozen */
1757
1758 /*
1759  * Only the _current_ task can read/write to tsk->flags, but other
1760  * tasks can access tsk->flags in readonly mode for example
1761  * with tsk_used_math (like during threaded core dumping).
1762  * There is however an exception to this rule during ptrace
1763  * or during fork: the ptracer task is allowed to write to the
1764  * child->flags of its traced child (same goes for fork, the parent
1765  * can write to the child->flags), because we're guaranteed the
1766  * child is not running and in turn not changing child->flags
1767  * at the same time the parent does it.
1768  */
1769 #define clear_stopped_child_used_math(child)    do { (child)->flags &= ~PF_USED_MATH; } while (0)
1770 #define set_stopped_child_used_math(child)      do { (child)->flags |= PF_USED_MATH; } while (0)
1771 #define clear_used_math()                       clear_stopped_child_used_math(current)
1772 #define set_used_math()                         set_stopped_child_used_math(current)
1773
1774 #define conditional_stopped_child_used_math(condition, child) \
1775         do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1776
1777 #define conditional_used_math(condition)        conditional_stopped_child_used_math(condition, current)
1778
1779 #define copy_to_stopped_child_used_math(child) \
1780         do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1781
1782 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1783 #define tsk_used_math(p)                        ((p)->flags & PF_USED_MATH)
1784 #define used_math()                             tsk_used_math(current)
1785
1786 static __always_inline bool is_percpu_thread(void)
1787 {
1788 #ifdef CONFIG_SMP
1789         return (current->flags & PF_NO_SETAFFINITY) &&
1790                 (current->nr_cpus_allowed  == 1);
1791 #else
1792         return true;
1793 #endif
1794 }
1795
1796 /* Per-process atomic flags. */
1797 #define PFA_NO_NEW_PRIVS                0       /* May not gain new privileges. */
1798 #define PFA_SPREAD_PAGE                 1       /* Spread page cache over cpuset */
1799 #define PFA_SPREAD_SLAB                 2       /* Spread some slab caches over cpuset */
1800 #define PFA_SPEC_SSB_DISABLE            3       /* Speculative Store Bypass disabled */
1801 #define PFA_SPEC_SSB_FORCE_DISABLE      4       /* Speculative Store Bypass force disabled*/
1802 #define PFA_SPEC_IB_DISABLE             5       /* Indirect branch speculation restricted */
1803 #define PFA_SPEC_IB_FORCE_DISABLE       6       /* Indirect branch speculation permanently restricted */
1804 #define PFA_SPEC_SSB_NOEXEC             7       /* Speculative Store Bypass clear on execve() */
1805
1806 #define TASK_PFA_TEST(name, func)                                       \
1807         static inline bool task_##func(struct task_struct *p)           \
1808         { return test_bit(PFA_##name, &p->atomic_flags); }
1809
1810 #define TASK_PFA_SET(name, func)                                        \
1811         static inline void task_set_##func(struct task_struct *p)       \
1812         { set_bit(PFA_##name, &p->atomic_flags); }
1813
1814 #define TASK_PFA_CLEAR(name, func)                                      \
1815         static inline void task_clear_##func(struct task_struct *p)     \
1816         { clear_bit(PFA_##name, &p->atomic_flags); }
1817
1818 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
1819 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
1820
1821 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
1822 TASK_PFA_SET(SPREAD_PAGE, spread_page)
1823 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
1824
1825 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
1826 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
1827 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
1828
1829 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable)
1830 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable)
1831 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable)
1832
1833 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1834 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1835 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1836
1837 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1838 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1839
1840 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable)
1841 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable)
1842 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable)
1843
1844 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1845 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1846
1847 static inline void
1848 current_restore_flags(unsigned long orig_flags, unsigned long flags)
1849 {
1850         current->flags &= ~flags;
1851         current->flags |= orig_flags & flags;
1852 }
1853
1854 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
1855 extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_effective_cpus);
1856 #ifdef CONFIG_SMP
1857 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
1858 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
1859 extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node);
1860 extern void release_user_cpus_ptr(struct task_struct *p);
1861 extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask);
1862 extern void force_compatible_cpus_allowed_ptr(struct task_struct *p);
1863 extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p);
1864 #else
1865 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
1866 {
1867 }
1868 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
1869 {
1870         if (!cpumask_test_cpu(0, new_mask))
1871                 return -EINVAL;
1872         return 0;
1873 }
1874 static inline int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node)
1875 {
1876         if (src->user_cpus_ptr)
1877                 return -EINVAL;
1878         return 0;
1879 }
1880 static inline void release_user_cpus_ptr(struct task_struct *p)
1881 {
1882         WARN_ON(p->user_cpus_ptr);
1883 }
1884
1885 static inline int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask)
1886 {
1887         return 0;
1888 }
1889 #endif
1890
1891 extern int yield_to(struct task_struct *p, bool preempt);
1892 extern void set_user_nice(struct task_struct *p, long nice);
1893 extern int task_prio(const struct task_struct *p);
1894
1895 /**
1896  * task_nice - return the nice value of a given task.
1897  * @p: the task in question.
1898  *
1899  * Return: The nice value [ -20 ... 0 ... 19 ].
1900  */
1901 static inline int task_nice(const struct task_struct *p)
1902 {
1903         return PRIO_TO_NICE((p)->static_prio);
1904 }
1905
1906 extern int can_nice(const struct task_struct *p, const int nice);
1907 extern int task_curr(const struct task_struct *p);
1908 extern int idle_cpu(int cpu);
1909 extern int available_idle_cpu(int cpu);
1910 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *);
1911 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *);
1912 extern void sched_set_fifo(struct task_struct *p);
1913 extern void sched_set_fifo_low(struct task_struct *p);
1914 extern void sched_set_normal(struct task_struct *p, int nice);
1915 extern int sched_setattr(struct task_struct *, const struct sched_attr *);
1916 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *);
1917 extern struct task_struct *idle_task(int cpu);
1918
1919 /**
1920  * is_idle_task - is the specified task an idle task?
1921  * @p: the task in question.
1922  *
1923  * Return: 1 if @p is an idle task. 0 otherwise.
1924  */
1925 static __always_inline bool is_idle_task(const struct task_struct *p)
1926 {
1927         return !!(p->flags & PF_IDLE);
1928 }
1929
1930 extern struct task_struct *curr_task(int cpu);
1931 extern void ia64_set_curr_task(int cpu, struct task_struct *p);
1932
1933 void yield(void);
1934
1935 union thread_union {
1936 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK
1937         struct task_struct task;
1938 #endif
1939 #ifndef CONFIG_THREAD_INFO_IN_TASK
1940         struct thread_info thread_info;
1941 #endif
1942         unsigned long stack[THREAD_SIZE/sizeof(long)];
1943 };
1944
1945 #ifndef CONFIG_THREAD_INFO_IN_TASK
1946 extern struct thread_info init_thread_info;
1947 #endif
1948
1949 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
1950
1951 #ifdef CONFIG_THREAD_INFO_IN_TASK
1952 # define task_thread_info(task) (&(task)->thread_info)
1953 #elif !defined(__HAVE_THREAD_FUNCTIONS)
1954 # define task_thread_info(task) ((struct thread_info *)(task)->stack)
1955 #endif
1956
1957 /*
1958  * find a task by one of its numerical ids
1959  *
1960  * find_task_by_pid_ns():
1961  *      finds a task by its pid in the specified namespace
1962  * find_task_by_vpid():
1963  *      finds a task by its virtual pid
1964  *
1965  * see also find_vpid() etc in include/linux/pid.h
1966  */
1967
1968 extern struct task_struct *find_task_by_vpid(pid_t nr);
1969 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns);
1970
1971 /*
1972  * find a task by its virtual pid and get the task struct
1973  */
1974 extern struct task_struct *find_get_task_by_vpid(pid_t nr);
1975
1976 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
1977 extern int wake_up_process(struct task_struct *tsk);
1978 extern void wake_up_new_task(struct task_struct *tsk);
1979
1980 #ifdef CONFIG_SMP
1981 extern void kick_process(struct task_struct *tsk);
1982 #else
1983 static inline void kick_process(struct task_struct *tsk) { }
1984 #endif
1985
1986 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
1987
1988 static inline void set_task_comm(struct task_struct *tsk, const char *from)
1989 {
1990         __set_task_comm(tsk, from, false);
1991 }
1992
1993 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk);
1994 #define get_task_comm(buf, tsk) ({                      \
1995         BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN);     \
1996         __get_task_comm(buf, sizeof(buf), tsk);         \
1997 })
1998
1999 #ifdef CONFIG_SMP
2000 static __always_inline void scheduler_ipi(void)
2001 {
2002         /*
2003          * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting
2004          * TIF_NEED_RESCHED remotely (for the first time) will also send
2005          * this IPI.
2006          */
2007         preempt_fold_need_resched();
2008 }
2009 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state);
2010 #else
2011 static inline void scheduler_ipi(void) { }
2012 static inline unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state)
2013 {
2014         return 1;
2015 }
2016 #endif
2017
2018 /*
2019  * Set thread flags in other task's structures.
2020  * See asm/thread_info.h for TIF_xxxx flags available:
2021  */
2022 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2023 {
2024         set_ti_thread_flag(task_thread_info(tsk), flag);
2025 }
2026
2027 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2028 {
2029         clear_ti_thread_flag(task_thread_info(tsk), flag);
2030 }
2031
2032 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag,
2033                                           bool value)
2034 {
2035         update_ti_thread_flag(task_thread_info(tsk), flag, value);
2036 }
2037
2038 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2039 {
2040         return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2041 }
2042
2043 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2044 {
2045         return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2046 }
2047
2048 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2049 {
2050         return test_ti_thread_flag(task_thread_info(tsk), flag);
2051 }
2052
2053 static inline void set_tsk_need_resched(struct task_struct *tsk)
2054 {
2055         set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2056 }
2057
2058 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2059 {
2060         clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2061 }
2062
2063 static inline int test_tsk_need_resched(struct task_struct *tsk)
2064 {
2065         return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2066 }
2067
2068 /*
2069  * cond_resched() and cond_resched_lock(): latency reduction via
2070  * explicit rescheduling in places that are safe. The return
2071  * value indicates whether a reschedule was done in fact.
2072  * cond_resched_lock() will drop the spinlock before scheduling,
2073  */
2074 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC)
2075 extern int __cond_resched(void);
2076
2077 #if defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL)
2078
2079 void sched_dynamic_klp_enable(void);
2080 void sched_dynamic_klp_disable(void);
2081
2082 DECLARE_STATIC_CALL(cond_resched, __cond_resched);
2083
2084 static __always_inline int _cond_resched(void)
2085 {
2086         return static_call_mod(cond_resched)();
2087 }
2088
2089 #elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY)
2090
2091 extern int dynamic_cond_resched(void);
2092
2093 static __always_inline int _cond_resched(void)
2094 {
2095         return dynamic_cond_resched();
2096 }
2097
2098 #else /* !CONFIG_PREEMPTION */
2099
2100 static inline int _cond_resched(void)
2101 {
2102         klp_sched_try_switch();
2103         return __cond_resched();
2104 }
2105
2106 #endif /* PREEMPT_DYNAMIC && CONFIG_HAVE_PREEMPT_DYNAMIC_CALL */
2107
2108 #else /* CONFIG_PREEMPTION && !CONFIG_PREEMPT_DYNAMIC */
2109
2110 static inline int _cond_resched(void)
2111 {
2112         klp_sched_try_switch();
2113         return 0;
2114 }
2115
2116 #endif /* !CONFIG_PREEMPTION || CONFIG_PREEMPT_DYNAMIC */
2117
2118 #define cond_resched() ({                       \
2119         __might_resched(__FILE__, __LINE__, 0); \
2120         _cond_resched();                        \
2121 })
2122
2123 extern int __cond_resched_lock(spinlock_t *lock);
2124 extern int __cond_resched_rwlock_read(rwlock_t *lock);
2125 extern int __cond_resched_rwlock_write(rwlock_t *lock);
2126
2127 #define MIGHT_RESCHED_RCU_SHIFT         8
2128 #define MIGHT_RESCHED_PREEMPT_MASK      ((1U << MIGHT_RESCHED_RCU_SHIFT) - 1)
2129
2130 #ifndef CONFIG_PREEMPT_RT
2131 /*
2132  * Non RT kernels have an elevated preempt count due to the held lock,
2133  * but are not allowed to be inside a RCU read side critical section
2134  */
2135 # define PREEMPT_LOCK_RESCHED_OFFSETS   PREEMPT_LOCK_OFFSET
2136 #else
2137 /*
2138  * spin/rw_lock() on RT implies rcu_read_lock(). The might_sleep() check in
2139  * cond_resched*lock() has to take that into account because it checks for
2140  * preempt_count() and rcu_preempt_depth().
2141  */
2142 # define PREEMPT_LOCK_RESCHED_OFFSETS   \
2143         (PREEMPT_LOCK_OFFSET + (1U << MIGHT_RESCHED_RCU_SHIFT))
2144 #endif
2145
2146 #define cond_resched_lock(lock) ({                                              \
2147         __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS);      \
2148         __cond_resched_lock(lock);                                              \
2149 })
2150
2151 #define cond_resched_rwlock_read(lock) ({                                       \
2152         __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS);      \
2153         __cond_resched_rwlock_read(lock);                                       \
2154 })
2155
2156 #define cond_resched_rwlock_write(lock) ({                                      \
2157         __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS);      \
2158         __cond_resched_rwlock_write(lock);                                      \
2159 })
2160
2161 static inline void cond_resched_rcu(void)
2162 {
2163 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
2164         rcu_read_unlock();
2165         cond_resched();
2166         rcu_read_lock();
2167 #endif
2168 }
2169
2170 #ifdef CONFIG_PREEMPT_DYNAMIC
2171
2172 extern bool preempt_model_none(void);
2173 extern bool preempt_model_voluntary(void);
2174 extern bool preempt_model_full(void);
2175
2176 #else
2177
2178 static inline bool preempt_model_none(void)
2179 {
2180         return IS_ENABLED(CONFIG_PREEMPT_NONE);
2181 }
2182 static inline bool preempt_model_voluntary(void)
2183 {
2184         return IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY);
2185 }
2186 static inline bool preempt_model_full(void)
2187 {
2188         return IS_ENABLED(CONFIG_PREEMPT);
2189 }
2190
2191 #endif
2192
2193 static inline bool preempt_model_rt(void)
2194 {
2195         return IS_ENABLED(CONFIG_PREEMPT_RT);
2196 }
2197
2198 /*
2199  * Does the preemption model allow non-cooperative preemption?
2200  *
2201  * For !CONFIG_PREEMPT_DYNAMIC kernels this is an exact match with
2202  * CONFIG_PREEMPTION; for CONFIG_PREEMPT_DYNAMIC this doesn't work as the
2203  * kernel is *built* with CONFIG_PREEMPTION=y but may run with e.g. the
2204  * PREEMPT_NONE model.
2205  */
2206 static inline bool preempt_model_preemptible(void)
2207 {
2208         return preempt_model_full() || preempt_model_rt();
2209 }
2210
2211 /*
2212  * Does a critical section need to be broken due to another
2213  * task waiting?: (technically does not depend on CONFIG_PREEMPTION,
2214  * but a general need for low latency)
2215  */
2216 static inline int spin_needbreak(spinlock_t *lock)
2217 {
2218 #ifdef CONFIG_PREEMPTION
2219         return spin_is_contended(lock);
2220 #else
2221         return 0;
2222 #endif
2223 }
2224
2225 /*
2226  * Check if a rwlock is contended.
2227  * Returns non-zero if there is another task waiting on the rwlock.
2228  * Returns zero if the lock is not contended or the system / underlying
2229  * rwlock implementation does not support contention detection.
2230  * Technically does not depend on CONFIG_PREEMPTION, but a general need
2231  * for low latency.
2232  */
2233 static inline int rwlock_needbreak(rwlock_t *lock)
2234 {
2235 #ifdef CONFIG_PREEMPTION
2236         return rwlock_is_contended(lock);
2237 #else
2238         return 0;
2239 #endif
2240 }
2241
2242 static __always_inline bool need_resched(void)
2243 {
2244         return unlikely(tif_need_resched());
2245 }
2246
2247 /*
2248  * Wrappers for p->thread_info->cpu access. No-op on UP.
2249  */
2250 #ifdef CONFIG_SMP
2251
2252 static inline unsigned int task_cpu(const struct task_struct *p)
2253 {
2254         return READ_ONCE(task_thread_info(p)->cpu);
2255 }
2256
2257 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2258
2259 #else
2260
2261 static inline unsigned int task_cpu(const struct task_struct *p)
2262 {
2263         return 0;
2264 }
2265
2266 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2267 {
2268 }
2269
2270 #endif /* CONFIG_SMP */
2271
2272 extern bool sched_task_on_rq(struct task_struct *p);
2273 extern unsigned long get_wchan(struct task_struct *p);
2274 extern struct task_struct *cpu_curr_snapshot(int cpu);
2275
2276 /*
2277  * In order to reduce various lock holder preemption latencies provide an
2278  * interface to see if a vCPU is currently running or not.
2279  *
2280  * This allows us to terminate optimistic spin loops and block, analogous to
2281  * the native optimistic spin heuristic of testing if the lock owner task is
2282  * running or not.
2283  */
2284 #ifndef vcpu_is_preempted
2285 static inline bool vcpu_is_preempted(int cpu)
2286 {
2287         return false;
2288 }
2289 #endif
2290
2291 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2292 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2293
2294 #ifndef TASK_SIZE_OF
2295 #define TASK_SIZE_OF(tsk)       TASK_SIZE
2296 #endif
2297
2298 #ifdef CONFIG_SMP
2299 static inline bool owner_on_cpu(struct task_struct *owner)
2300 {
2301         /*
2302          * As lock holder preemption issue, we both skip spinning if
2303          * task is not on cpu or its cpu is preempted
2304          */
2305         return READ_ONCE(owner->on_cpu) && !vcpu_is_preempted(task_cpu(owner));
2306 }
2307
2308 /* Returns effective CPU energy utilization, as seen by the scheduler */
2309 unsigned long sched_cpu_util(int cpu);
2310 #endif /* CONFIG_SMP */
2311
2312 #ifdef CONFIG_RSEQ
2313
2314 /*
2315  * Map the event mask on the user-space ABI enum rseq_cs_flags
2316  * for direct mask checks.
2317  */
2318 enum rseq_event_mask_bits {
2319         RSEQ_EVENT_PREEMPT_BIT  = RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT,
2320         RSEQ_EVENT_SIGNAL_BIT   = RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT,
2321         RSEQ_EVENT_MIGRATE_BIT  = RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT,
2322 };
2323
2324 enum rseq_event_mask {
2325         RSEQ_EVENT_PREEMPT      = (1U << RSEQ_EVENT_PREEMPT_BIT),
2326         RSEQ_EVENT_SIGNAL       = (1U << RSEQ_EVENT_SIGNAL_BIT),
2327         RSEQ_EVENT_MIGRATE      = (1U << RSEQ_EVENT_MIGRATE_BIT),
2328 };
2329
2330 static inline void rseq_set_notify_resume(struct task_struct *t)
2331 {
2332         if (t->rseq)
2333                 set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
2334 }
2335
2336 void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs);
2337
2338 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
2339                                              struct pt_regs *regs)
2340 {
2341         if (current->rseq)
2342                 __rseq_handle_notify_resume(ksig, regs);
2343 }
2344
2345 static inline void rseq_signal_deliver(struct ksignal *ksig,
2346                                        struct pt_regs *regs)
2347 {
2348         preempt_disable();
2349         __set_bit(RSEQ_EVENT_SIGNAL_BIT, &current->rseq_event_mask);
2350         preempt_enable();
2351         rseq_handle_notify_resume(ksig, regs);
2352 }
2353
2354 /* rseq_preempt() requires preemption to be disabled. */
2355 static inline void rseq_preempt(struct task_struct *t)
2356 {
2357         __set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask);
2358         rseq_set_notify_resume(t);
2359 }
2360
2361 /* rseq_migrate() requires preemption to be disabled. */
2362 static inline void rseq_migrate(struct task_struct *t)
2363 {
2364         __set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask);
2365         rseq_set_notify_resume(t);
2366 }
2367
2368 /*
2369  * If parent process has a registered restartable sequences area, the
2370  * child inherits. Unregister rseq for a clone with CLONE_VM set.
2371  */
2372 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
2373 {
2374         if (clone_flags & CLONE_VM) {
2375                 t->rseq = NULL;
2376                 t->rseq_len = 0;
2377                 t->rseq_sig = 0;
2378                 t->rseq_event_mask = 0;
2379         } else {
2380                 t->rseq = current->rseq;
2381                 t->rseq_len = current->rseq_len;
2382                 t->rseq_sig = current->rseq_sig;
2383                 t->rseq_event_mask = current->rseq_event_mask;
2384         }
2385 }
2386
2387 static inline void rseq_execve(struct task_struct *t)
2388 {
2389         t->rseq = NULL;
2390         t->rseq_len = 0;
2391         t->rseq_sig = 0;
2392         t->rseq_event_mask = 0;
2393 }
2394
2395 #else
2396
2397 static inline void rseq_set_notify_resume(struct task_struct *t)
2398 {
2399 }
2400 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
2401                                              struct pt_regs *regs)
2402 {
2403 }
2404 static inline void rseq_signal_deliver(struct ksignal *ksig,
2405                                        struct pt_regs *regs)
2406 {
2407 }
2408 static inline void rseq_preempt(struct task_struct *t)
2409 {
2410 }
2411 static inline void rseq_migrate(struct task_struct *t)
2412 {
2413 }
2414 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
2415 {
2416 }
2417 static inline void rseq_execve(struct task_struct *t)
2418 {
2419 }
2420
2421 #endif
2422
2423 #ifdef CONFIG_DEBUG_RSEQ
2424
2425 void rseq_syscall(struct pt_regs *regs);
2426
2427 #else
2428
2429 static inline void rseq_syscall(struct pt_regs *regs)
2430 {
2431 }
2432
2433 #endif
2434
2435 #ifdef CONFIG_SCHED_CORE
2436 extern void sched_core_free(struct task_struct *tsk);
2437 extern void sched_core_fork(struct task_struct *p);
2438 extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type,
2439                                 unsigned long uaddr);
2440 #else
2441 static inline void sched_core_free(struct task_struct *tsk) { }
2442 static inline void sched_core_fork(struct task_struct *p) { }
2443 #endif
2444
2445 extern void sched_set_stop_task(int cpu, struct task_struct *stop);
2446
2447 #endif