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 <asm/kmap_size.h> 40 41 /* task_struct member predeclarations (sorted alphabetically): */ 42 struct audit_context; 43 struct backing_dev_info; 44 struct bio_list; 45 struct blk_plug; 46 struct bpf_local_storage; 47 struct bpf_run_ctx; 48 struct capture_control; 49 struct cfs_rq; 50 struct fs_struct; 51 struct futex_pi_state; 52 struct io_context; 53 struct io_uring_task; 54 struct mempolicy; 55 struct nameidata; 56 struct nsproxy; 57 struct perf_event_context; 58 struct pid_namespace; 59 struct pipe_inode_info; 60 struct rcu_node; 61 struct reclaim_state; 62 struct robust_list_head; 63 struct root_domain; 64 struct rq; 65 struct sched_attr; 66 struct sched_param; 67 struct seq_file; 68 struct sighand_struct; 69 struct signal_struct; 70 struct task_delay_info; 71 struct task_group; 72 73 /* 74 * Task state bitmask. NOTE! These bits are also 75 * encoded in fs/proc/array.c: get_task_state(). 76 * 77 * We have two separate sets of flags: task->state 78 * is about runnability, while task->exit_state are 79 * about the task exiting. Confusing, but this way 80 * modifying one set can't modify the other one by 81 * mistake. 82 */ 83 84 /* Used in tsk->state: */ 85 #define TASK_RUNNING 0x00000000 86 #define TASK_INTERRUPTIBLE 0x00000001 87 #define TASK_UNINTERRUPTIBLE 0x00000002 88 #define __TASK_STOPPED 0x00000004 89 #define __TASK_TRACED 0x00000008 90 /* Used in tsk->exit_state: */ 91 #define EXIT_DEAD 0x00000010 92 #define EXIT_ZOMBIE 0x00000020 93 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD) 94 /* Used in tsk->state again: */ 95 #define TASK_PARKED 0x00000040 96 #define TASK_DEAD 0x00000080 97 #define TASK_WAKEKILL 0x00000100 98 #define TASK_WAKING 0x00000200 99 #define TASK_NOLOAD 0x00000400 100 #define TASK_NEW 0x00000800 101 #define TASK_RTLOCK_WAIT 0x00001000 102 #define TASK_FREEZABLE 0x00002000 103 #define __TASK_FREEZABLE_UNSAFE (0x00004000 * IS_ENABLED(CONFIG_LOCKDEP)) 104 #define TASK_FROZEN 0x00008000 105 #define TASK_STATE_MAX 0x00010000 106 107 #define TASK_ANY (TASK_STATE_MAX-1) 108 109 /* 110 * DO NOT ADD ANY NEW USERS ! 111 */ 112 #define TASK_FREEZABLE_UNSAFE (TASK_FREEZABLE | __TASK_FREEZABLE_UNSAFE) 113 114 /* Convenience macros for the sake of set_current_state: */ 115 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE) 116 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED) 117 #define TASK_TRACED __TASK_TRACED 118 119 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD) 120 121 /* Convenience macros for the sake of wake_up(): */ 122 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE) 123 124 /* get_task_state(): */ 125 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \ 126 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \ 127 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \ 128 TASK_PARKED) 129 130 #define task_is_running(task) (READ_ONCE((task)->__state) == TASK_RUNNING) 131 132 #define task_is_traced(task) ((READ_ONCE(task->jobctl) & JOBCTL_TRACED) != 0) 133 #define task_is_stopped(task) ((READ_ONCE(task->jobctl) & JOBCTL_STOPPED) != 0) 134 #define task_is_stopped_or_traced(task) ((READ_ONCE(task->jobctl) & (JOBCTL_STOPPED | JOBCTL_TRACED)) != 0) 135 136 /* 137 * Special states are those that do not use the normal wait-loop pattern. See 138 * the comment with set_special_state(). 139 */ 140 #define is_special_task_state(state) \ 141 ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD)) 142 143 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 144 # define debug_normal_state_change(state_value) \ 145 do { \ 146 WARN_ON_ONCE(is_special_task_state(state_value)); \ 147 current->task_state_change = _THIS_IP_; \ 148 } while (0) 149 150 # define debug_special_state_change(state_value) \ 151 do { \ 152 WARN_ON_ONCE(!is_special_task_state(state_value)); \ 153 current->task_state_change = _THIS_IP_; \ 154 } while (0) 155 156 # define debug_rtlock_wait_set_state() \ 157 do { \ 158 current->saved_state_change = current->task_state_change;\ 159 current->task_state_change = _THIS_IP_; \ 160 } while (0) 161 162 # define debug_rtlock_wait_restore_state() \ 163 do { \ 164 current->task_state_change = current->saved_state_change;\ 165 } while (0) 166 167 #else 168 # define debug_normal_state_change(cond) do { } while (0) 169 # define debug_special_state_change(cond) do { } while (0) 170 # define debug_rtlock_wait_set_state() do { } while (0) 171 # define debug_rtlock_wait_restore_state() do { } while (0) 172 #endif 173 174 /* 175 * set_current_state() includes a barrier so that the write of current->state 176 * is correctly serialised wrt the caller's subsequent test of whether to 177 * actually sleep: 178 * 179 * for (;;) { 180 * set_current_state(TASK_UNINTERRUPTIBLE); 181 * if (CONDITION) 182 * break; 183 * 184 * schedule(); 185 * } 186 * __set_current_state(TASK_RUNNING); 187 * 188 * If the caller does not need such serialisation (because, for instance, the 189 * CONDITION test and condition change and wakeup are under the same lock) then 190 * use __set_current_state(). 191 * 192 * The above is typically ordered against the wakeup, which does: 193 * 194 * CONDITION = 1; 195 * wake_up_state(p, TASK_UNINTERRUPTIBLE); 196 * 197 * where wake_up_state()/try_to_wake_up() executes a full memory barrier before 198 * accessing p->state. 199 * 200 * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is, 201 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a 202 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING). 203 * 204 * However, with slightly different timing the wakeup TASK_RUNNING store can 205 * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not 206 * a problem either because that will result in one extra go around the loop 207 * and our @cond test will save the day. 208 * 209 * Also see the comments of try_to_wake_up(). 210 */ 211 #define __set_current_state(state_value) \ 212 do { \ 213 debug_normal_state_change((state_value)); \ 214 WRITE_ONCE(current->__state, (state_value)); \ 215 } while (0) 216 217 #define set_current_state(state_value) \ 218 do { \ 219 debug_normal_state_change((state_value)); \ 220 smp_store_mb(current->__state, (state_value)); \ 221 } while (0) 222 223 /* 224 * set_special_state() should be used for those states when the blocking task 225 * can not use the regular condition based wait-loop. In that case we must 226 * serialize against wakeups such that any possible in-flight TASK_RUNNING 227 * stores will not collide with our state change. 228 */ 229 #define set_special_state(state_value) \ 230 do { \ 231 unsigned long flags; /* may shadow */ \ 232 \ 233 raw_spin_lock_irqsave(¤t->pi_lock, flags); \ 234 debug_special_state_change((state_value)); \ 235 WRITE_ONCE(current->__state, (state_value)); \ 236 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \ 237 } while (0) 238 239 /* 240 * PREEMPT_RT specific variants for "sleeping" spin/rwlocks 241 * 242 * RT's spin/rwlock substitutions are state preserving. The state of the 243 * task when blocking on the lock is saved in task_struct::saved_state and 244 * restored after the lock has been acquired. These operations are 245 * serialized by task_struct::pi_lock against try_to_wake_up(). Any non RT 246 * lock related wakeups while the task is blocked on the lock are 247 * redirected to operate on task_struct::saved_state to ensure that these 248 * are not dropped. On restore task_struct::saved_state is set to 249 * TASK_RUNNING so any wakeup attempt redirected to saved_state will fail. 250 * 251 * The lock operation looks like this: 252 * 253 * current_save_and_set_rtlock_wait_state(); 254 * for (;;) { 255 * if (try_lock()) 256 * break; 257 * raw_spin_unlock_irq(&lock->wait_lock); 258 * schedule_rtlock(); 259 * raw_spin_lock_irq(&lock->wait_lock); 260 * set_current_state(TASK_RTLOCK_WAIT); 261 * } 262 * current_restore_rtlock_saved_state(); 263 */ 264 #define current_save_and_set_rtlock_wait_state() \ 265 do { \ 266 lockdep_assert_irqs_disabled(); \ 267 raw_spin_lock(¤t->pi_lock); \ 268 current->saved_state = current->__state; \ 269 debug_rtlock_wait_set_state(); \ 270 WRITE_ONCE(current->__state, TASK_RTLOCK_WAIT); \ 271 raw_spin_unlock(¤t->pi_lock); \ 272 } while (0); 273 274 #define current_restore_rtlock_saved_state() \ 275 do { \ 276 lockdep_assert_irqs_disabled(); \ 277 raw_spin_lock(¤t->pi_lock); \ 278 debug_rtlock_wait_restore_state(); \ 279 WRITE_ONCE(current->__state, current->saved_state); \ 280 current->saved_state = TASK_RUNNING; \ 281 raw_spin_unlock(¤t->pi_lock); \ 282 } while (0); 283 284 #define get_current_state() READ_ONCE(current->__state) 285 286 /* 287 * Define the task command name length as enum, then it can be visible to 288 * BPF programs. 289 */ 290 enum { 291 TASK_COMM_LEN = 16, 292 }; 293 294 extern void scheduler_tick(void); 295 296 #define MAX_SCHEDULE_TIMEOUT LONG_MAX 297 298 extern long schedule_timeout(long timeout); 299 extern long schedule_timeout_interruptible(long timeout); 300 extern long schedule_timeout_killable(long timeout); 301 extern long schedule_timeout_uninterruptible(long timeout); 302 extern long schedule_timeout_idle(long timeout); 303 asmlinkage void schedule(void); 304 extern void schedule_preempt_disabled(void); 305 asmlinkage void preempt_schedule_irq(void); 306 #ifdef CONFIG_PREEMPT_RT 307 extern void schedule_rtlock(void); 308 #endif 309 310 extern int __must_check io_schedule_prepare(void); 311 extern void io_schedule_finish(int token); 312 extern long io_schedule_timeout(long timeout); 313 extern void io_schedule(void); 314 315 /** 316 * struct prev_cputime - snapshot of system and user cputime 317 * @utime: time spent in user mode 318 * @stime: time spent in system mode 319 * @lock: protects the above two fields 320 * 321 * Stores previous user/system time values such that we can guarantee 322 * monotonicity. 323 */ 324 struct prev_cputime { 325 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE 326 u64 utime; 327 u64 stime; 328 raw_spinlock_t lock; 329 #endif 330 }; 331 332 enum vtime_state { 333 /* Task is sleeping or running in a CPU with VTIME inactive: */ 334 VTIME_INACTIVE = 0, 335 /* Task is idle */ 336 VTIME_IDLE, 337 /* Task runs in kernelspace in a CPU with VTIME active: */ 338 VTIME_SYS, 339 /* Task runs in userspace in a CPU with VTIME active: */ 340 VTIME_USER, 341 /* Task runs as guests in a CPU with VTIME active: */ 342 VTIME_GUEST, 343 }; 344 345 struct vtime { 346 seqcount_t seqcount; 347 unsigned long long starttime; 348 enum vtime_state state; 349 unsigned int cpu; 350 u64 utime; 351 u64 stime; 352 u64 gtime; 353 }; 354 355 /* 356 * Utilization clamp constraints. 357 * @UCLAMP_MIN: Minimum utilization 358 * @UCLAMP_MAX: Maximum utilization 359 * @UCLAMP_CNT: Utilization clamp constraints count 360 */ 361 enum uclamp_id { 362 UCLAMP_MIN = 0, 363 UCLAMP_MAX, 364 UCLAMP_CNT 365 }; 366 367 #ifdef CONFIG_SMP 368 extern struct root_domain def_root_domain; 369 extern struct mutex sched_domains_mutex; 370 #endif 371 372 struct sched_info { 373 #ifdef CONFIG_SCHED_INFO 374 /* Cumulative counters: */ 375 376 /* # of times we have run on this CPU: */ 377 unsigned long pcount; 378 379 /* Time spent waiting on a runqueue: */ 380 unsigned long long run_delay; 381 382 /* Timestamps: */ 383 384 /* When did we last run on a CPU? */ 385 unsigned long long last_arrival; 386 387 /* When were we last queued to run? */ 388 unsigned long long last_queued; 389 390 #endif /* CONFIG_SCHED_INFO */ 391 }; 392 393 /* 394 * Integer metrics need fixed point arithmetic, e.g., sched/fair 395 * has a few: load, load_avg, util_avg, freq, and capacity. 396 * 397 * We define a basic fixed point arithmetic range, and then formalize 398 * all these metrics based on that basic range. 399 */ 400 # define SCHED_FIXEDPOINT_SHIFT 10 401 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT) 402 403 /* Increase resolution of cpu_capacity calculations */ 404 # define SCHED_CAPACITY_SHIFT SCHED_FIXEDPOINT_SHIFT 405 # define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT) 406 407 struct load_weight { 408 unsigned long weight; 409 u32 inv_weight; 410 }; 411 412 /** 413 * struct util_est - Estimation utilization of FAIR tasks 414 * @enqueued: instantaneous estimated utilization of a task/cpu 415 * @ewma: the Exponential Weighted Moving Average (EWMA) 416 * utilization of a task 417 * 418 * Support data structure to track an Exponential Weighted Moving Average 419 * (EWMA) of a FAIR task's utilization. New samples are added to the moving 420 * average each time a task completes an activation. Sample's weight is chosen 421 * so that the EWMA will be relatively insensitive to transient changes to the 422 * task's workload. 423 * 424 * The enqueued attribute has a slightly different meaning for tasks and cpus: 425 * - task: the task's util_avg at last task dequeue time 426 * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU 427 * Thus, the util_est.enqueued of a task represents the contribution on the 428 * estimated utilization of the CPU where that task is currently enqueued. 429 * 430 * Only for tasks we track a moving average of the past instantaneous 431 * estimated utilization. This allows to absorb sporadic drops in utilization 432 * of an otherwise almost periodic task. 433 * 434 * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg 435 * updates. When a task is dequeued, its util_est should not be updated if its 436 * util_avg has not been updated in the meantime. 437 * This information is mapped into the MSB bit of util_est.enqueued at dequeue 438 * time. Since max value of util_est.enqueued for a task is 1024 (PELT util_avg 439 * for a task) it is safe to use MSB. 440 */ 441 struct util_est { 442 unsigned int enqueued; 443 unsigned int ewma; 444 #define UTIL_EST_WEIGHT_SHIFT 2 445 #define UTIL_AVG_UNCHANGED 0x80000000 446 } __attribute__((__aligned__(sizeof(u64)))); 447 448 /* 449 * The load/runnable/util_avg accumulates an infinite geometric series 450 * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c). 451 * 452 * [load_avg definition] 453 * 454 * load_avg = runnable% * scale_load_down(load) 455 * 456 * [runnable_avg definition] 457 * 458 * runnable_avg = runnable% * SCHED_CAPACITY_SCALE 459 * 460 * [util_avg definition] 461 * 462 * util_avg = running% * SCHED_CAPACITY_SCALE 463 * 464 * where runnable% is the time ratio that a sched_entity is runnable and 465 * running% the time ratio that a sched_entity is running. 466 * 467 * For cfs_rq, they are the aggregated values of all runnable and blocked 468 * sched_entities. 469 * 470 * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU 471 * capacity scaling. The scaling is done through the rq_clock_pelt that is used 472 * for computing those signals (see update_rq_clock_pelt()) 473 * 474 * N.B., the above ratios (runnable% and running%) themselves are in the 475 * range of [0, 1]. To do fixed point arithmetics, we therefore scale them 476 * to as large a range as necessary. This is for example reflected by 477 * util_avg's SCHED_CAPACITY_SCALE. 478 * 479 * [Overflow issue] 480 * 481 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities 482 * with the highest load (=88761), always runnable on a single cfs_rq, 483 * and should not overflow as the number already hits PID_MAX_LIMIT. 484 * 485 * For all other cases (including 32-bit kernels), struct load_weight's 486 * weight will overflow first before we do, because: 487 * 488 * Max(load_avg) <= Max(load.weight) 489 * 490 * Then it is the load_weight's responsibility to consider overflow 491 * issues. 492 */ 493 struct sched_avg { 494 u64 last_update_time; 495 u64 load_sum; 496 u64 runnable_sum; 497 u32 util_sum; 498 u32 period_contrib; 499 unsigned long load_avg; 500 unsigned long runnable_avg; 501 unsigned long util_avg; 502 struct util_est util_est; 503 } ____cacheline_aligned; 504 505 struct sched_statistics { 506 #ifdef CONFIG_SCHEDSTATS 507 u64 wait_start; 508 u64 wait_max; 509 u64 wait_count; 510 u64 wait_sum; 511 u64 iowait_count; 512 u64 iowait_sum; 513 514 u64 sleep_start; 515 u64 sleep_max; 516 s64 sum_sleep_runtime; 517 518 u64 block_start; 519 u64 block_max; 520 s64 sum_block_runtime; 521 522 u64 exec_max; 523 u64 slice_max; 524 525 u64 nr_migrations_cold; 526 u64 nr_failed_migrations_affine; 527 u64 nr_failed_migrations_running; 528 u64 nr_failed_migrations_hot; 529 u64 nr_forced_migrations; 530 531 u64 nr_wakeups; 532 u64 nr_wakeups_sync; 533 u64 nr_wakeups_migrate; 534 u64 nr_wakeups_local; 535 u64 nr_wakeups_remote; 536 u64 nr_wakeups_affine; 537 u64 nr_wakeups_affine_attempts; 538 u64 nr_wakeups_passive; 539 u64 nr_wakeups_idle; 540 541 #ifdef CONFIG_SCHED_CORE 542 u64 core_forceidle_sum; 543 #endif 544 #endif /* CONFIG_SCHEDSTATS */ 545 } ____cacheline_aligned; 546 547 struct sched_entity { 548 /* For load-balancing: */ 549 struct load_weight load; 550 struct rb_node run_node; 551 struct list_head group_node; 552 unsigned int on_rq; 553 554 u64 exec_start; 555 u64 sum_exec_runtime; 556 u64 vruntime; 557 u64 prev_sum_exec_runtime; 558 559 u64 nr_migrations; 560 561 #ifdef CONFIG_FAIR_GROUP_SCHED 562 int depth; 563 struct sched_entity *parent; 564 /* rq on which this entity is (to be) queued: */ 565 struct cfs_rq *cfs_rq; 566 /* rq "owned" by this entity/group: */ 567 struct cfs_rq *my_q; 568 /* cached value of my_q->h_nr_running */ 569 unsigned long runnable_weight; 570 #endif 571 572 #ifdef CONFIG_SMP 573 /* 574 * Per entity load average tracking. 575 * 576 * Put into separate cache line so it does not 577 * collide with read-mostly values above. 578 */ 579 struct sched_avg avg; 580 #endif 581 }; 582 583 struct sched_rt_entity { 584 struct list_head run_list; 585 unsigned long timeout; 586 unsigned long watchdog_stamp; 587 unsigned int time_slice; 588 unsigned short on_rq; 589 unsigned short on_list; 590 591 struct sched_rt_entity *back; 592 #ifdef CONFIG_RT_GROUP_SCHED 593 struct sched_rt_entity *parent; 594 /* rq on which this entity is (to be) queued: */ 595 struct rt_rq *rt_rq; 596 /* rq "owned" by this entity/group: */ 597 struct rt_rq *my_q; 598 #endif 599 } __randomize_layout; 600 601 struct sched_dl_entity { 602 struct rb_node rb_node; 603 604 /* 605 * Original scheduling parameters. Copied here from sched_attr 606 * during sched_setattr(), they will remain the same until 607 * the next sched_setattr(). 608 */ 609 u64 dl_runtime; /* Maximum runtime for each instance */ 610 u64 dl_deadline; /* Relative deadline of each instance */ 611 u64 dl_period; /* Separation of two instances (period) */ 612 u64 dl_bw; /* dl_runtime / dl_period */ 613 u64 dl_density; /* dl_runtime / dl_deadline */ 614 615 /* 616 * Actual scheduling parameters. Initialized with the values above, 617 * they are continuously updated during task execution. Note that 618 * the remaining runtime could be < 0 in case we are in overrun. 619 */ 620 s64 runtime; /* Remaining runtime for this instance */ 621 u64 deadline; /* Absolute deadline for this instance */ 622 unsigned int flags; /* Specifying the scheduler behaviour */ 623 624 /* 625 * Some bool flags: 626 * 627 * @dl_throttled tells if we exhausted the runtime. If so, the 628 * task has to wait for a replenishment to be performed at the 629 * next firing of dl_timer. 630 * 631 * @dl_yielded tells if task gave up the CPU before consuming 632 * all its available runtime during the last job. 633 * 634 * @dl_non_contending tells if the task is inactive while still 635 * contributing to the active utilization. In other words, it 636 * indicates if the inactive timer has been armed and its handler 637 * has not been executed yet. This flag is useful to avoid race 638 * conditions between the inactive timer handler and the wakeup 639 * code. 640 * 641 * @dl_overrun tells if the task asked to be informed about runtime 642 * overruns. 643 */ 644 unsigned int dl_throttled : 1; 645 unsigned int dl_yielded : 1; 646 unsigned int dl_non_contending : 1; 647 unsigned int dl_overrun : 1; 648 649 /* 650 * Bandwidth enforcement timer. Each -deadline task has its 651 * own bandwidth to be enforced, thus we need one timer per task. 652 */ 653 struct hrtimer dl_timer; 654 655 /* 656 * Inactive timer, responsible for decreasing the active utilization 657 * at the "0-lag time". When a -deadline task blocks, it contributes 658 * to GRUB's active utilization until the "0-lag time", hence a 659 * timer is needed to decrease the active utilization at the correct 660 * time. 661 */ 662 struct hrtimer inactive_timer; 663 664 #ifdef CONFIG_RT_MUTEXES 665 /* 666 * Priority Inheritance. When a DEADLINE scheduling entity is boosted 667 * pi_se points to the donor, otherwise points to the dl_se it belongs 668 * to (the original one/itself). 669 */ 670 struct sched_dl_entity *pi_se; 671 #endif 672 }; 673 674 #ifdef CONFIG_UCLAMP_TASK 675 /* Number of utilization clamp buckets (shorter alias) */ 676 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT 677 678 /* 679 * Utilization clamp for a scheduling entity 680 * @value: clamp value "assigned" to a se 681 * @bucket_id: bucket index corresponding to the "assigned" value 682 * @active: the se is currently refcounted in a rq's bucket 683 * @user_defined: the requested clamp value comes from user-space 684 * 685 * The bucket_id is the index of the clamp bucket matching the clamp value 686 * which is pre-computed and stored to avoid expensive integer divisions from 687 * the fast path. 688 * 689 * The active bit is set whenever a task has got an "effective" value assigned, 690 * which can be different from the clamp value "requested" from user-space. 691 * This allows to know a task is refcounted in the rq's bucket corresponding 692 * to the "effective" bucket_id. 693 * 694 * The user_defined bit is set whenever a task has got a task-specific clamp 695 * value requested from userspace, i.e. the system defaults apply to this task 696 * just as a restriction. This allows to relax default clamps when a less 697 * restrictive task-specific value has been requested, thus allowing to 698 * implement a "nice" semantic. For example, a task running with a 20% 699 * default boost can still drop its own boosting to 0%. 700 */ 701 struct uclamp_se { 702 unsigned int value : bits_per(SCHED_CAPACITY_SCALE); 703 unsigned int bucket_id : bits_per(UCLAMP_BUCKETS); 704 unsigned int active : 1; 705 unsigned int user_defined : 1; 706 }; 707 #endif /* CONFIG_UCLAMP_TASK */ 708 709 union rcu_special { 710 struct { 711 u8 blocked; 712 u8 need_qs; 713 u8 exp_hint; /* Hint for performance. */ 714 u8 need_mb; /* Readers need smp_mb(). */ 715 } b; /* Bits. */ 716 u32 s; /* Set of bits. */ 717 }; 718 719 enum perf_event_task_context { 720 perf_invalid_context = -1, 721 perf_hw_context = 0, 722 perf_sw_context, 723 perf_nr_task_contexts, 724 }; 725 726 struct wake_q_node { 727 struct wake_q_node *next; 728 }; 729 730 struct kmap_ctrl { 731 #ifdef CONFIG_KMAP_LOCAL 732 int idx; 733 pte_t pteval[KM_MAX_IDX]; 734 #endif 735 }; 736 737 struct task_struct { 738 #ifdef CONFIG_THREAD_INFO_IN_TASK 739 /* 740 * For reasons of header soup (see current_thread_info()), this 741 * must be the first element of task_struct. 742 */ 743 struct thread_info thread_info; 744 #endif 745 unsigned int __state; 746 747 #ifdef CONFIG_PREEMPT_RT 748 /* saved state for "spinlock sleepers" */ 749 unsigned int saved_state; 750 #endif 751 752 /* 753 * This begins the randomizable portion of task_struct. Only 754 * scheduling-critical items should be added above here. 755 */ 756 randomized_struct_fields_start 757 758 void *stack; 759 refcount_t usage; 760 /* Per task flags (PF_*), defined further below: */ 761 unsigned int flags; 762 unsigned int ptrace; 763 764 #ifdef CONFIG_SMP 765 int on_cpu; 766 struct __call_single_node wake_entry; 767 unsigned int wakee_flips; 768 unsigned long wakee_flip_decay_ts; 769 struct task_struct *last_wakee; 770 771 /* 772 * recent_used_cpu is initially set as the last CPU used by a task 773 * that wakes affine another task. Waker/wakee relationships can 774 * push tasks around a CPU where each wakeup moves to the next one. 775 * Tracking a recently used CPU allows a quick search for a recently 776 * used CPU that may be idle. 777 */ 778 int recent_used_cpu; 779 int wake_cpu; 780 #endif 781 int on_rq; 782 783 int prio; 784 int static_prio; 785 int normal_prio; 786 unsigned int rt_priority; 787 788 struct sched_entity se; 789 struct sched_rt_entity rt; 790 struct sched_dl_entity dl; 791 const struct sched_class *sched_class; 792 793 #ifdef CONFIG_SCHED_CORE 794 struct rb_node core_node; 795 unsigned long core_cookie; 796 unsigned int core_occupation; 797 #endif 798 799 #ifdef CONFIG_CGROUP_SCHED 800 struct task_group *sched_task_group; 801 #endif 802 803 #ifdef CONFIG_UCLAMP_TASK 804 /* 805 * Clamp values requested for a scheduling entity. 806 * Must be updated with task_rq_lock() held. 807 */ 808 struct uclamp_se uclamp_req[UCLAMP_CNT]; 809 /* 810 * Effective clamp values used for a scheduling entity. 811 * Must be updated with task_rq_lock() held. 812 */ 813 struct uclamp_se uclamp[UCLAMP_CNT]; 814 #endif 815 816 struct sched_statistics stats; 817 818 #ifdef CONFIG_PREEMPT_NOTIFIERS 819 /* List of struct preempt_notifier: */ 820 struct hlist_head preempt_notifiers; 821 #endif 822 823 #ifdef CONFIG_BLK_DEV_IO_TRACE 824 unsigned int btrace_seq; 825 #endif 826 827 unsigned int policy; 828 int nr_cpus_allowed; 829 const cpumask_t *cpus_ptr; 830 cpumask_t *user_cpus_ptr; 831 cpumask_t cpus_mask; 832 void *migration_pending; 833 #ifdef CONFIG_SMP 834 unsigned short migration_disabled; 835 #endif 836 unsigned short migration_flags; 837 838 #ifdef CONFIG_PREEMPT_RCU 839 int rcu_read_lock_nesting; 840 union rcu_special rcu_read_unlock_special; 841 struct list_head rcu_node_entry; 842 struct rcu_node *rcu_blocked_node; 843 #endif /* #ifdef CONFIG_PREEMPT_RCU */ 844 845 #ifdef CONFIG_TASKS_RCU 846 unsigned long rcu_tasks_nvcsw; 847 u8 rcu_tasks_holdout; 848 u8 rcu_tasks_idx; 849 int rcu_tasks_idle_cpu; 850 struct list_head rcu_tasks_holdout_list; 851 #endif /* #ifdef CONFIG_TASKS_RCU */ 852 853 #ifdef CONFIG_TASKS_TRACE_RCU 854 int trc_reader_nesting; 855 int trc_ipi_to_cpu; 856 union rcu_special trc_reader_special; 857 struct list_head trc_holdout_list; 858 struct list_head trc_blkd_node; 859 int trc_blkd_cpu; 860 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */ 861 862 struct sched_info sched_info; 863 864 struct list_head tasks; 865 #ifdef CONFIG_SMP 866 struct plist_node pushable_tasks; 867 struct rb_node pushable_dl_tasks; 868 #endif 869 870 struct mm_struct *mm; 871 struct mm_struct *active_mm; 872 873 int exit_state; 874 int exit_code; 875 int exit_signal; 876 /* The signal sent when the parent dies: */ 877 int pdeath_signal; 878 /* JOBCTL_*, siglock protected: */ 879 unsigned long jobctl; 880 881 /* Used for emulating ABI behavior of previous Linux versions: */ 882 unsigned int personality; 883 884 /* Scheduler bits, serialized by scheduler locks: */ 885 unsigned sched_reset_on_fork:1; 886 unsigned sched_contributes_to_load:1; 887 unsigned sched_migrated:1; 888 889 /* Force alignment to the next boundary: */ 890 unsigned :0; 891 892 /* Unserialized, strictly 'current' */ 893 894 /* 895 * This field must not be in the scheduler word above due to wakelist 896 * queueing no longer being serialized by p->on_cpu. However: 897 * 898 * p->XXX = X; ttwu() 899 * schedule() if (p->on_rq && ..) // false 900 * smp_mb__after_spinlock(); if (smp_load_acquire(&p->on_cpu) && //true 901 * deactivate_task() ttwu_queue_wakelist()) 902 * p->on_rq = 0; p->sched_remote_wakeup = Y; 903 * 904 * guarantees all stores of 'current' are visible before 905 * ->sched_remote_wakeup gets used, so it can be in this word. 906 */ 907 unsigned sched_remote_wakeup:1; 908 909 /* Bit to tell LSMs we're in execve(): */ 910 unsigned in_execve:1; 911 unsigned in_iowait:1; 912 #ifndef TIF_RESTORE_SIGMASK 913 unsigned restore_sigmask:1; 914 #endif 915 #ifdef CONFIG_MEMCG 916 unsigned in_user_fault:1; 917 #endif 918 #ifdef CONFIG_LRU_GEN 919 /* whether the LRU algorithm may apply to this access */ 920 unsigned in_lru_fault:1; 921 #endif 922 #ifdef CONFIG_COMPAT_BRK 923 unsigned brk_randomized:1; 924 #endif 925 #ifdef CONFIG_CGROUPS 926 /* disallow userland-initiated cgroup migration */ 927 unsigned no_cgroup_migration:1; 928 /* task is frozen/stopped (used by the cgroup freezer) */ 929 unsigned frozen:1; 930 #endif 931 #ifdef CONFIG_BLK_CGROUP 932 unsigned use_memdelay:1; 933 #endif 934 #ifdef CONFIG_PSI 935 /* Stalled due to lack of memory */ 936 unsigned in_memstall:1; 937 #endif 938 #ifdef CONFIG_PAGE_OWNER 939 /* Used by page_owner=on to detect recursion in page tracking. */ 940 unsigned in_page_owner:1; 941 #endif 942 #ifdef CONFIG_EVENTFD 943 /* Recursion prevention for eventfd_signal() */ 944 unsigned in_eventfd:1; 945 #endif 946 #ifdef CONFIG_IOMMU_SVA 947 unsigned pasid_activated:1; 948 #endif 949 #ifdef CONFIG_CPU_SUP_INTEL 950 unsigned reported_split_lock:1; 951 #endif 952 #ifdef CONFIG_TASK_DELAY_ACCT 953 /* delay due to memory thrashing */ 954 unsigned in_thrashing:1; 955 #endif 956 957 unsigned long atomic_flags; /* Flags requiring atomic access. */ 958 959 struct restart_block restart_block; 960 961 pid_t pid; 962 pid_t tgid; 963 964 #ifdef CONFIG_STACKPROTECTOR 965 /* Canary value for the -fstack-protector GCC feature: */ 966 unsigned long stack_canary; 967 #endif 968 /* 969 * Pointers to the (original) parent process, youngest child, younger sibling, 970 * older sibling, respectively. (p->father can be replaced with 971 * p->real_parent->pid) 972 */ 973 974 /* Real parent process: */ 975 struct task_struct __rcu *real_parent; 976 977 /* Recipient of SIGCHLD, wait4() reports: */ 978 struct task_struct __rcu *parent; 979 980 /* 981 * Children/sibling form the list of natural children: 982 */ 983 struct list_head children; 984 struct list_head sibling; 985 struct task_struct *group_leader; 986 987 /* 988 * 'ptraced' is the list of tasks this task is using ptrace() on. 989 * 990 * This includes both natural children and PTRACE_ATTACH targets. 991 * 'ptrace_entry' is this task's link on the p->parent->ptraced list. 992 */ 993 struct list_head ptraced; 994 struct list_head ptrace_entry; 995 996 /* PID/PID hash table linkage. */ 997 struct pid *thread_pid; 998 struct hlist_node pid_links[PIDTYPE_MAX]; 999 struct list_head thread_group; 1000 struct list_head thread_node; 1001 1002 struct completion *vfork_done; 1003 1004 /* CLONE_CHILD_SETTID: */ 1005 int __user *set_child_tid; 1006 1007 /* CLONE_CHILD_CLEARTID: */ 1008 int __user *clear_child_tid; 1009 1010 /* PF_KTHREAD | PF_IO_WORKER */ 1011 void *worker_private; 1012 1013 u64 utime; 1014 u64 stime; 1015 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME 1016 u64 utimescaled; 1017 u64 stimescaled; 1018 #endif 1019 u64 gtime; 1020 struct prev_cputime prev_cputime; 1021 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN 1022 struct vtime vtime; 1023 #endif 1024 1025 #ifdef CONFIG_NO_HZ_FULL 1026 atomic_t tick_dep_mask; 1027 #endif 1028 /* Context switch counts: */ 1029 unsigned long nvcsw; 1030 unsigned long nivcsw; 1031 1032 /* Monotonic time in nsecs: */ 1033 u64 start_time; 1034 1035 /* Boot based time in nsecs: */ 1036 u64 start_boottime; 1037 1038 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */ 1039 unsigned long min_flt; 1040 unsigned long maj_flt; 1041 1042 /* Empty if CONFIG_POSIX_CPUTIMERS=n */ 1043 struct posix_cputimers posix_cputimers; 1044 1045 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK 1046 struct posix_cputimers_work posix_cputimers_work; 1047 #endif 1048 1049 /* Process credentials: */ 1050 1051 /* Tracer's credentials at attach: */ 1052 const struct cred __rcu *ptracer_cred; 1053 1054 /* Objective and real subjective task credentials (COW): */ 1055 const struct cred __rcu *real_cred; 1056 1057 /* Effective (overridable) subjective task credentials (COW): */ 1058 const struct cred __rcu *cred; 1059 1060 #ifdef CONFIG_KEYS 1061 /* Cached requested key. */ 1062 struct key *cached_requested_key; 1063 #endif 1064 1065 /* 1066 * executable name, excluding path. 1067 * 1068 * - normally initialized setup_new_exec() 1069 * - access it with [gs]et_task_comm() 1070 * - lock it with task_lock() 1071 */ 1072 char comm[TASK_COMM_LEN]; 1073 1074 struct nameidata *nameidata; 1075 1076 #ifdef CONFIG_SYSVIPC 1077 struct sysv_sem sysvsem; 1078 struct sysv_shm sysvshm; 1079 #endif 1080 #ifdef CONFIG_DETECT_HUNG_TASK 1081 unsigned long last_switch_count; 1082 unsigned long last_switch_time; 1083 #endif 1084 /* Filesystem information: */ 1085 struct fs_struct *fs; 1086 1087 /* Open file information: */ 1088 struct files_struct *files; 1089 1090 #ifdef CONFIG_IO_URING 1091 struct io_uring_task *io_uring; 1092 #endif 1093 1094 /* Namespaces: */ 1095 struct nsproxy *nsproxy; 1096 1097 /* Signal handlers: */ 1098 struct signal_struct *signal; 1099 struct sighand_struct __rcu *sighand; 1100 sigset_t blocked; 1101 sigset_t real_blocked; 1102 /* Restored if set_restore_sigmask() was used: */ 1103 sigset_t saved_sigmask; 1104 struct sigpending pending; 1105 unsigned long sas_ss_sp; 1106 size_t sas_ss_size; 1107 unsigned int sas_ss_flags; 1108 1109 struct callback_head *task_works; 1110 1111 #ifdef CONFIG_AUDIT 1112 #ifdef CONFIG_AUDITSYSCALL 1113 struct audit_context *audit_context; 1114 #endif 1115 kuid_t loginuid; 1116 unsigned int sessionid; 1117 #endif 1118 struct seccomp seccomp; 1119 struct syscall_user_dispatch syscall_dispatch; 1120 1121 /* Thread group tracking: */ 1122 u64 parent_exec_id; 1123 u64 self_exec_id; 1124 1125 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */ 1126 spinlock_t alloc_lock; 1127 1128 /* Protection of the PI data structures: */ 1129 raw_spinlock_t pi_lock; 1130 1131 struct wake_q_node wake_q; 1132 1133 #ifdef CONFIG_RT_MUTEXES 1134 /* PI waiters blocked on a rt_mutex held by this task: */ 1135 struct rb_root_cached pi_waiters; 1136 /* Updated under owner's pi_lock and rq lock */ 1137 struct task_struct *pi_top_task; 1138 /* Deadlock detection and priority inheritance handling: */ 1139 struct rt_mutex_waiter *pi_blocked_on; 1140 #endif 1141 1142 #ifdef CONFIG_DEBUG_MUTEXES 1143 /* Mutex deadlock detection: */ 1144 struct mutex_waiter *blocked_on; 1145 #endif 1146 1147 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1148 int non_block_count; 1149 #endif 1150 1151 #ifdef CONFIG_TRACE_IRQFLAGS 1152 struct irqtrace_events irqtrace; 1153 unsigned int hardirq_threaded; 1154 u64 hardirq_chain_key; 1155 int softirqs_enabled; 1156 int softirq_context; 1157 int irq_config; 1158 #endif 1159 #ifdef CONFIG_PREEMPT_RT 1160 int softirq_disable_cnt; 1161 #endif 1162 1163 #ifdef CONFIG_LOCKDEP 1164 # define MAX_LOCK_DEPTH 48UL 1165 u64 curr_chain_key; 1166 int lockdep_depth; 1167 unsigned int lockdep_recursion; 1168 struct held_lock held_locks[MAX_LOCK_DEPTH]; 1169 #endif 1170 1171 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP) 1172 unsigned int in_ubsan; 1173 #endif 1174 1175 /* Journalling filesystem info: */ 1176 void *journal_info; 1177 1178 /* Stacked block device info: */ 1179 struct bio_list *bio_list; 1180 1181 /* Stack plugging: */ 1182 struct blk_plug *plug; 1183 1184 /* VM state: */ 1185 struct reclaim_state *reclaim_state; 1186 1187 struct backing_dev_info *backing_dev_info; 1188 1189 struct io_context *io_context; 1190 1191 #ifdef CONFIG_COMPACTION 1192 struct capture_control *capture_control; 1193 #endif 1194 /* Ptrace state: */ 1195 unsigned long ptrace_message; 1196 kernel_siginfo_t *last_siginfo; 1197 1198 struct task_io_accounting ioac; 1199 #ifdef CONFIG_PSI 1200 /* Pressure stall state */ 1201 unsigned int psi_flags; 1202 #endif 1203 #ifdef CONFIG_TASK_XACCT 1204 /* Accumulated RSS usage: */ 1205 u64 acct_rss_mem1; 1206 /* Accumulated virtual memory usage: */ 1207 u64 acct_vm_mem1; 1208 /* stime + utime since last update: */ 1209 u64 acct_timexpd; 1210 #endif 1211 #ifdef CONFIG_CPUSETS 1212 /* Protected by ->alloc_lock: */ 1213 nodemask_t mems_allowed; 1214 /* Sequence number to catch updates: */ 1215 seqcount_spinlock_t mems_allowed_seq; 1216 int cpuset_mem_spread_rotor; 1217 int cpuset_slab_spread_rotor; 1218 #endif 1219 #ifdef CONFIG_CGROUPS 1220 /* Control Group info protected by css_set_lock: */ 1221 struct css_set __rcu *cgroups; 1222 /* cg_list protected by css_set_lock and tsk->alloc_lock: */ 1223 struct list_head cg_list; 1224 #endif 1225 #ifdef CONFIG_X86_CPU_RESCTRL 1226 u32 closid; 1227 u32 rmid; 1228 #endif 1229 #ifdef CONFIG_FUTEX 1230 struct robust_list_head __user *robust_list; 1231 #ifdef CONFIG_COMPAT 1232 struct compat_robust_list_head __user *compat_robust_list; 1233 #endif 1234 struct list_head pi_state_list; 1235 struct futex_pi_state *pi_state_cache; 1236 struct mutex futex_exit_mutex; 1237 unsigned int futex_state; 1238 #endif 1239 #ifdef CONFIG_PERF_EVENTS 1240 struct perf_event_context *perf_event_ctxp; 1241 struct mutex perf_event_mutex; 1242 struct list_head perf_event_list; 1243 #endif 1244 #ifdef CONFIG_DEBUG_PREEMPT 1245 unsigned long preempt_disable_ip; 1246 #endif 1247 #ifdef CONFIG_NUMA 1248 /* Protected by alloc_lock: */ 1249 struct mempolicy *mempolicy; 1250 short il_prev; 1251 short pref_node_fork; 1252 #endif 1253 #ifdef CONFIG_NUMA_BALANCING 1254 int numa_scan_seq; 1255 unsigned int numa_scan_period; 1256 unsigned int numa_scan_period_max; 1257 int numa_preferred_nid; 1258 unsigned long numa_migrate_retry; 1259 /* Migration stamp: */ 1260 u64 node_stamp; 1261 u64 last_task_numa_placement; 1262 u64 last_sum_exec_runtime; 1263 struct callback_head numa_work; 1264 1265 /* 1266 * This pointer is only modified for current in syscall and 1267 * pagefault context (and for tasks being destroyed), so it can be read 1268 * from any of the following contexts: 1269 * - RCU read-side critical section 1270 * - current->numa_group from everywhere 1271 * - task's runqueue locked, task not running 1272 */ 1273 struct numa_group __rcu *numa_group; 1274 1275 /* 1276 * numa_faults is an array split into four regions: 1277 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer 1278 * in this precise order. 1279 * 1280 * faults_memory: Exponential decaying average of faults on a per-node 1281 * basis. Scheduling placement decisions are made based on these 1282 * counts. The values remain static for the duration of a PTE scan. 1283 * faults_cpu: Track the nodes the process was running on when a NUMA 1284 * hinting fault was incurred. 1285 * faults_memory_buffer and faults_cpu_buffer: Record faults per node 1286 * during the current scan window. When the scan completes, the counts 1287 * in faults_memory and faults_cpu decay and these values are copied. 1288 */ 1289 unsigned long *numa_faults; 1290 unsigned long total_numa_faults; 1291 1292 /* 1293 * numa_faults_locality tracks if faults recorded during the last 1294 * scan window were remote/local or failed to migrate. The task scan 1295 * period is adapted based on the locality of the faults with different 1296 * weights depending on whether they were shared or private faults 1297 */ 1298 unsigned long numa_faults_locality[3]; 1299 1300 unsigned long numa_pages_migrated; 1301 #endif /* CONFIG_NUMA_BALANCING */ 1302 1303 #ifdef CONFIG_RSEQ 1304 struct rseq __user *rseq; 1305 u32 rseq_len; 1306 u32 rseq_sig; 1307 /* 1308 * RmW on rseq_event_mask must be performed atomically 1309 * with respect to preemption. 1310 */ 1311 unsigned long rseq_event_mask; 1312 #endif 1313 1314 #ifdef CONFIG_SCHED_MM_CID 1315 int mm_cid; /* Current cid in mm */ 1316 int mm_cid_active; /* Whether cid bitmap is active */ 1317 #endif 1318 1319 struct tlbflush_unmap_batch tlb_ubc; 1320 1321 /* Cache last used pipe for splice(): */ 1322 struct pipe_inode_info *splice_pipe; 1323 1324 struct page_frag task_frag; 1325 1326 #ifdef CONFIG_TASK_DELAY_ACCT 1327 struct task_delay_info *delays; 1328 #endif 1329 1330 #ifdef CONFIG_FAULT_INJECTION 1331 int make_it_fail; 1332 unsigned int fail_nth; 1333 #endif 1334 /* 1335 * When (nr_dirtied >= nr_dirtied_pause), it's time to call 1336 * balance_dirty_pages() for a dirty throttling pause: 1337 */ 1338 int nr_dirtied; 1339 int nr_dirtied_pause; 1340 /* Start of a write-and-pause period: */ 1341 unsigned long dirty_paused_when; 1342 1343 #ifdef CONFIG_LATENCYTOP 1344 int latency_record_count; 1345 struct latency_record latency_record[LT_SAVECOUNT]; 1346 #endif 1347 /* 1348 * Time slack values; these are used to round up poll() and 1349 * select() etc timeout values. These are in nanoseconds. 1350 */ 1351 u64 timer_slack_ns; 1352 u64 default_timer_slack_ns; 1353 1354 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) 1355 unsigned int kasan_depth; 1356 #endif 1357 1358 #ifdef CONFIG_KCSAN 1359 struct kcsan_ctx kcsan_ctx; 1360 #ifdef CONFIG_TRACE_IRQFLAGS 1361 struct irqtrace_events kcsan_save_irqtrace; 1362 #endif 1363 #ifdef CONFIG_KCSAN_WEAK_MEMORY 1364 int kcsan_stack_depth; 1365 #endif 1366 #endif 1367 1368 #ifdef CONFIG_KMSAN 1369 struct kmsan_ctx kmsan_ctx; 1370 #endif 1371 1372 #if IS_ENABLED(CONFIG_KUNIT) 1373 struct kunit *kunit_test; 1374 #endif 1375 1376 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 1377 /* Index of current stored address in ret_stack: */ 1378 int curr_ret_stack; 1379 int curr_ret_depth; 1380 1381 /* Stack of return addresses for return function tracing: */ 1382 struct ftrace_ret_stack *ret_stack; 1383 1384 /* Timestamp for last schedule: */ 1385 unsigned long long ftrace_timestamp; 1386 1387 /* 1388 * Number of functions that haven't been traced 1389 * because of depth overrun: 1390 */ 1391 atomic_t trace_overrun; 1392 1393 /* Pause tracing: */ 1394 atomic_t tracing_graph_pause; 1395 #endif 1396 1397 #ifdef CONFIG_TRACING 1398 /* Bitmask and counter of trace recursion: */ 1399 unsigned long trace_recursion; 1400 #endif /* CONFIG_TRACING */ 1401 1402 #ifdef CONFIG_KCOV 1403 /* See kernel/kcov.c for more details. */ 1404 1405 /* Coverage collection mode enabled for this task (0 if disabled): */ 1406 unsigned int kcov_mode; 1407 1408 /* Size of the kcov_area: */ 1409 unsigned int kcov_size; 1410 1411 /* Buffer for coverage collection: */ 1412 void *kcov_area; 1413 1414 /* KCOV descriptor wired with this task or NULL: */ 1415 struct kcov *kcov; 1416 1417 /* KCOV common handle for remote coverage collection: */ 1418 u64 kcov_handle; 1419 1420 /* KCOV sequence number: */ 1421 int kcov_sequence; 1422 1423 /* Collect coverage from softirq context: */ 1424 unsigned int kcov_softirq; 1425 #endif 1426 1427 #ifdef CONFIG_MEMCG 1428 struct mem_cgroup *memcg_in_oom; 1429 gfp_t memcg_oom_gfp_mask; 1430 int memcg_oom_order; 1431 1432 /* Number of pages to reclaim on returning to userland: */ 1433 unsigned int memcg_nr_pages_over_high; 1434 1435 /* Used by memcontrol for targeted memcg charge: */ 1436 struct mem_cgroup *active_memcg; 1437 #endif 1438 1439 #ifdef CONFIG_BLK_CGROUP 1440 struct gendisk *throttle_disk; 1441 #endif 1442 1443 #ifdef CONFIG_UPROBES 1444 struct uprobe_task *utask; 1445 #endif 1446 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE) 1447 unsigned int sequential_io; 1448 unsigned int sequential_io_avg; 1449 #endif 1450 struct kmap_ctrl kmap_ctrl; 1451 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1452 unsigned long task_state_change; 1453 # ifdef CONFIG_PREEMPT_RT 1454 unsigned long saved_state_change; 1455 # endif 1456 #endif 1457 struct rcu_head rcu; 1458 refcount_t rcu_users; 1459 int pagefault_disabled; 1460 #ifdef CONFIG_MMU 1461 struct task_struct *oom_reaper_list; 1462 struct timer_list oom_reaper_timer; 1463 #endif 1464 #ifdef CONFIG_VMAP_STACK 1465 struct vm_struct *stack_vm_area; 1466 #endif 1467 #ifdef CONFIG_THREAD_INFO_IN_TASK 1468 /* A live task holds one reference: */ 1469 refcount_t stack_refcount; 1470 #endif 1471 #ifdef CONFIG_LIVEPATCH 1472 int patch_state; 1473 #endif 1474 #ifdef CONFIG_SECURITY 1475 /* Used by LSM modules for access restriction: */ 1476 void *security; 1477 #endif 1478 #ifdef CONFIG_BPF_SYSCALL 1479 /* Used by BPF task local storage */ 1480 struct bpf_local_storage __rcu *bpf_storage; 1481 /* Used for BPF run context */ 1482 struct bpf_run_ctx *bpf_ctx; 1483 #endif 1484 1485 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK 1486 unsigned long lowest_stack; 1487 unsigned long prev_lowest_stack; 1488 #endif 1489 1490 #ifdef CONFIG_X86_MCE 1491 void __user *mce_vaddr; 1492 __u64 mce_kflags; 1493 u64 mce_addr; 1494 __u64 mce_ripv : 1, 1495 mce_whole_page : 1, 1496 __mce_reserved : 62; 1497 struct callback_head mce_kill_me; 1498 int mce_count; 1499 #endif 1500 1501 #ifdef CONFIG_KRETPROBES 1502 struct llist_head kretprobe_instances; 1503 #endif 1504 #ifdef CONFIG_RETHOOK 1505 struct llist_head rethooks; 1506 #endif 1507 1508 #ifdef CONFIG_ARCH_HAS_PARANOID_L1D_FLUSH 1509 /* 1510 * If L1D flush is supported on mm context switch 1511 * then we use this callback head to queue kill work 1512 * to kill tasks that are not running on SMT disabled 1513 * cores 1514 */ 1515 struct callback_head l1d_flush_kill; 1516 #endif 1517 1518 #ifdef CONFIG_RV 1519 /* 1520 * Per-task RV monitor. Nowadays fixed in RV_PER_TASK_MONITORS. 1521 * If we find justification for more monitors, we can think 1522 * about adding more or developing a dynamic method. So far, 1523 * none of these are justified. 1524 */ 1525 union rv_task_monitor rv[RV_PER_TASK_MONITORS]; 1526 #endif 1527 1528 /* 1529 * New fields for task_struct should be added above here, so that 1530 * they are included in the randomized portion of task_struct. 1531 */ 1532 randomized_struct_fields_end 1533 1534 /* CPU-specific state of this task: */ 1535 struct thread_struct thread; 1536 1537 /* 1538 * WARNING: on x86, 'thread_struct' contains a variable-sized 1539 * structure. It *MUST* be at the end of 'task_struct'. 1540 * 1541 * Do not put anything below here! 1542 */ 1543 }; 1544 1545 static inline struct pid *task_pid(struct task_struct *task) 1546 { 1547 return task->thread_pid; 1548 } 1549 1550 /* 1551 * the helpers to get the task's different pids as they are seen 1552 * from various namespaces 1553 * 1554 * task_xid_nr() : global id, i.e. the id seen from the init namespace; 1555 * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of 1556 * current. 1557 * task_xid_nr_ns() : id seen from the ns specified; 1558 * 1559 * see also pid_nr() etc in include/linux/pid.h 1560 */ 1561 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns); 1562 1563 static inline pid_t task_pid_nr(struct task_struct *tsk) 1564 { 1565 return tsk->pid; 1566 } 1567 1568 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1569 { 1570 return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns); 1571 } 1572 1573 static inline pid_t task_pid_vnr(struct task_struct *tsk) 1574 { 1575 return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL); 1576 } 1577 1578 1579 static inline pid_t task_tgid_nr(struct task_struct *tsk) 1580 { 1581 return tsk->tgid; 1582 } 1583 1584 /** 1585 * pid_alive - check that a task structure is not stale 1586 * @p: Task structure to be checked. 1587 * 1588 * Test if a process is not yet dead (at most zombie state) 1589 * If pid_alive fails, then pointers within the task structure 1590 * can be stale and must not be dereferenced. 1591 * 1592 * Return: 1 if the process is alive. 0 otherwise. 1593 */ 1594 static inline int pid_alive(const struct task_struct *p) 1595 { 1596 return p->thread_pid != NULL; 1597 } 1598 1599 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1600 { 1601 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns); 1602 } 1603 1604 static inline pid_t task_pgrp_vnr(struct task_struct *tsk) 1605 { 1606 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL); 1607 } 1608 1609 1610 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1611 { 1612 return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns); 1613 } 1614 1615 static inline pid_t task_session_vnr(struct task_struct *tsk) 1616 { 1617 return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL); 1618 } 1619 1620 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1621 { 1622 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, ns); 1623 } 1624 1625 static inline pid_t task_tgid_vnr(struct task_struct *tsk) 1626 { 1627 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, NULL); 1628 } 1629 1630 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns) 1631 { 1632 pid_t pid = 0; 1633 1634 rcu_read_lock(); 1635 if (pid_alive(tsk)) 1636 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns); 1637 rcu_read_unlock(); 1638 1639 return pid; 1640 } 1641 1642 static inline pid_t task_ppid_nr(const struct task_struct *tsk) 1643 { 1644 return task_ppid_nr_ns(tsk, &init_pid_ns); 1645 } 1646 1647 /* Obsolete, do not use: */ 1648 static inline pid_t task_pgrp_nr(struct task_struct *tsk) 1649 { 1650 return task_pgrp_nr_ns(tsk, &init_pid_ns); 1651 } 1652 1653 #define TASK_REPORT_IDLE (TASK_REPORT + 1) 1654 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1) 1655 1656 static inline unsigned int __task_state_index(unsigned int tsk_state, 1657 unsigned int tsk_exit_state) 1658 { 1659 unsigned int state = (tsk_state | tsk_exit_state) & TASK_REPORT; 1660 1661 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX); 1662 1663 if (tsk_state == TASK_IDLE) 1664 state = TASK_REPORT_IDLE; 1665 1666 /* 1667 * We're lying here, but rather than expose a completely new task state 1668 * to userspace, we can make this appear as if the task has gone through 1669 * a regular rt_mutex_lock() call. 1670 */ 1671 if (tsk_state == TASK_RTLOCK_WAIT) 1672 state = TASK_UNINTERRUPTIBLE; 1673 1674 return fls(state); 1675 } 1676 1677 static inline unsigned int task_state_index(struct task_struct *tsk) 1678 { 1679 return __task_state_index(READ_ONCE(tsk->__state), tsk->exit_state); 1680 } 1681 1682 static inline char task_index_to_char(unsigned int state) 1683 { 1684 static const char state_char[] = "RSDTtXZPI"; 1685 1686 BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1); 1687 1688 return state_char[state]; 1689 } 1690 1691 static inline char task_state_to_char(struct task_struct *tsk) 1692 { 1693 return task_index_to_char(task_state_index(tsk)); 1694 } 1695 1696 /** 1697 * is_global_init - check if a task structure is init. Since init 1698 * is free to have sub-threads we need to check tgid. 1699 * @tsk: Task structure to be checked. 1700 * 1701 * Check if a task structure is the first user space task the kernel created. 1702 * 1703 * Return: 1 if the task structure is init. 0 otherwise. 1704 */ 1705 static inline int is_global_init(struct task_struct *tsk) 1706 { 1707 return task_tgid_nr(tsk) == 1; 1708 } 1709 1710 extern struct pid *cad_pid; 1711 1712 /* 1713 * Per process flags 1714 */ 1715 #define PF_VCPU 0x00000001 /* I'm a virtual CPU */ 1716 #define PF_IDLE 0x00000002 /* I am an IDLE thread */ 1717 #define PF_EXITING 0x00000004 /* Getting shut down */ 1718 #define PF_POSTCOREDUMP 0x00000008 /* Coredumps should ignore this task */ 1719 #define PF_IO_WORKER 0x00000010 /* Task is an IO worker */ 1720 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */ 1721 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */ 1722 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */ 1723 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */ 1724 #define PF_DUMPCORE 0x00000200 /* Dumped core */ 1725 #define PF_SIGNALED 0x00000400 /* Killed by a signal */ 1726 #define PF_MEMALLOC 0x00000800 /* Allocating memory */ 1727 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */ 1728 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */ 1729 #define PF__HOLE__00004000 0x00004000 1730 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */ 1731 #define PF__HOLE__00010000 0x00010000 1732 #define PF_KSWAPD 0x00020000 /* I am kswapd */ 1733 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocation requests will inherit GFP_NOFS */ 1734 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocation requests will inherit GFP_NOIO */ 1735 #define PF_LOCAL_THROTTLE 0x00100000 /* Throttle writes only against the bdi I write to, 1736 * I am cleaning dirty pages from some other bdi. */ 1737 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */ 1738 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */ 1739 #define PF__HOLE__00800000 0x00800000 1740 #define PF__HOLE__01000000 0x01000000 1741 #define PF__HOLE__02000000 0x02000000 1742 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */ 1743 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */ 1744 #define PF_MEMALLOC_PIN 0x10000000 /* Allocation context constrained to zones which allow long term pinning. */ 1745 #define PF__HOLE__20000000 0x20000000 1746 #define PF__HOLE__40000000 0x40000000 1747 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */ 1748 1749 /* 1750 * Only the _current_ task can read/write to tsk->flags, but other 1751 * tasks can access tsk->flags in readonly mode for example 1752 * with tsk_used_math (like during threaded core dumping). 1753 * There is however an exception to this rule during ptrace 1754 * or during fork: the ptracer task is allowed to write to the 1755 * child->flags of its traced child (same goes for fork, the parent 1756 * can write to the child->flags), because we're guaranteed the 1757 * child is not running and in turn not changing child->flags 1758 * at the same time the parent does it. 1759 */ 1760 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0) 1761 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0) 1762 #define clear_used_math() clear_stopped_child_used_math(current) 1763 #define set_used_math() set_stopped_child_used_math(current) 1764 1765 #define conditional_stopped_child_used_math(condition, child) \ 1766 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0) 1767 1768 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current) 1769 1770 #define copy_to_stopped_child_used_math(child) \ 1771 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0) 1772 1773 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */ 1774 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH) 1775 #define used_math() tsk_used_math(current) 1776 1777 static __always_inline bool is_percpu_thread(void) 1778 { 1779 #ifdef CONFIG_SMP 1780 return (current->flags & PF_NO_SETAFFINITY) && 1781 (current->nr_cpus_allowed == 1); 1782 #else 1783 return true; 1784 #endif 1785 } 1786 1787 /* Per-process atomic flags. */ 1788 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */ 1789 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */ 1790 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */ 1791 #define PFA_SPEC_SSB_DISABLE 3 /* Speculative Store Bypass disabled */ 1792 #define PFA_SPEC_SSB_FORCE_DISABLE 4 /* Speculative Store Bypass force disabled*/ 1793 #define PFA_SPEC_IB_DISABLE 5 /* Indirect branch speculation restricted */ 1794 #define PFA_SPEC_IB_FORCE_DISABLE 6 /* Indirect branch speculation permanently restricted */ 1795 #define PFA_SPEC_SSB_NOEXEC 7 /* Speculative Store Bypass clear on execve() */ 1796 1797 #define TASK_PFA_TEST(name, func) \ 1798 static inline bool task_##func(struct task_struct *p) \ 1799 { return test_bit(PFA_##name, &p->atomic_flags); } 1800 1801 #define TASK_PFA_SET(name, func) \ 1802 static inline void task_set_##func(struct task_struct *p) \ 1803 { set_bit(PFA_##name, &p->atomic_flags); } 1804 1805 #define TASK_PFA_CLEAR(name, func) \ 1806 static inline void task_clear_##func(struct task_struct *p) \ 1807 { clear_bit(PFA_##name, &p->atomic_flags); } 1808 1809 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs) 1810 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs) 1811 1812 TASK_PFA_TEST(SPREAD_PAGE, spread_page) 1813 TASK_PFA_SET(SPREAD_PAGE, spread_page) 1814 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page) 1815 1816 TASK_PFA_TEST(SPREAD_SLAB, spread_slab) 1817 TASK_PFA_SET(SPREAD_SLAB, spread_slab) 1818 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab) 1819 1820 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable) 1821 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable) 1822 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable) 1823 1824 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1825 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1826 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1827 1828 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1829 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1830 1831 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable) 1832 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable) 1833 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable) 1834 1835 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1836 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1837 1838 static inline void 1839 current_restore_flags(unsigned long orig_flags, unsigned long flags) 1840 { 1841 current->flags &= ~flags; 1842 current->flags |= orig_flags & flags; 1843 } 1844 1845 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial); 1846 extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_effective_cpus); 1847 #ifdef CONFIG_SMP 1848 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask); 1849 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask); 1850 extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node); 1851 extern void release_user_cpus_ptr(struct task_struct *p); 1852 extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask); 1853 extern void force_compatible_cpus_allowed_ptr(struct task_struct *p); 1854 extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p); 1855 #else 1856 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) 1857 { 1858 } 1859 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) 1860 { 1861 if (!cpumask_test_cpu(0, new_mask)) 1862 return -EINVAL; 1863 return 0; 1864 } 1865 static inline int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node) 1866 { 1867 if (src->user_cpus_ptr) 1868 return -EINVAL; 1869 return 0; 1870 } 1871 static inline void release_user_cpus_ptr(struct task_struct *p) 1872 { 1873 WARN_ON(p->user_cpus_ptr); 1874 } 1875 1876 static inline int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask) 1877 { 1878 return 0; 1879 } 1880 #endif 1881 1882 extern int yield_to(struct task_struct *p, bool preempt); 1883 extern void set_user_nice(struct task_struct *p, long nice); 1884 extern int task_prio(const struct task_struct *p); 1885 1886 /** 1887 * task_nice - return the nice value of a given task. 1888 * @p: the task in question. 1889 * 1890 * Return: The nice value [ -20 ... 0 ... 19 ]. 1891 */ 1892 static inline int task_nice(const struct task_struct *p) 1893 { 1894 return PRIO_TO_NICE((p)->static_prio); 1895 } 1896 1897 extern int can_nice(const struct task_struct *p, const int nice); 1898 extern int task_curr(const struct task_struct *p); 1899 extern int idle_cpu(int cpu); 1900 extern int available_idle_cpu(int cpu); 1901 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *); 1902 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *); 1903 extern void sched_set_fifo(struct task_struct *p); 1904 extern void sched_set_fifo_low(struct task_struct *p); 1905 extern void sched_set_normal(struct task_struct *p, int nice); 1906 extern int sched_setattr(struct task_struct *, const struct sched_attr *); 1907 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *); 1908 extern struct task_struct *idle_task(int cpu); 1909 1910 /** 1911 * is_idle_task - is the specified task an idle task? 1912 * @p: the task in question. 1913 * 1914 * Return: 1 if @p is an idle task. 0 otherwise. 1915 */ 1916 static __always_inline bool is_idle_task(const struct task_struct *p) 1917 { 1918 return !!(p->flags & PF_IDLE); 1919 } 1920 1921 extern struct task_struct *curr_task(int cpu); 1922 extern void ia64_set_curr_task(int cpu, struct task_struct *p); 1923 1924 void yield(void); 1925 1926 union thread_union { 1927 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK 1928 struct task_struct task; 1929 #endif 1930 #ifndef CONFIG_THREAD_INFO_IN_TASK 1931 struct thread_info thread_info; 1932 #endif 1933 unsigned long stack[THREAD_SIZE/sizeof(long)]; 1934 }; 1935 1936 #ifndef CONFIG_THREAD_INFO_IN_TASK 1937 extern struct thread_info init_thread_info; 1938 #endif 1939 1940 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)]; 1941 1942 #ifdef CONFIG_THREAD_INFO_IN_TASK 1943 # define task_thread_info(task) (&(task)->thread_info) 1944 #elif !defined(__HAVE_THREAD_FUNCTIONS) 1945 # define task_thread_info(task) ((struct thread_info *)(task)->stack) 1946 #endif 1947 1948 /* 1949 * find a task by one of its numerical ids 1950 * 1951 * find_task_by_pid_ns(): 1952 * finds a task by its pid in the specified namespace 1953 * find_task_by_vpid(): 1954 * finds a task by its virtual pid 1955 * 1956 * see also find_vpid() etc in include/linux/pid.h 1957 */ 1958 1959 extern struct task_struct *find_task_by_vpid(pid_t nr); 1960 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns); 1961 1962 /* 1963 * find a task by its virtual pid and get the task struct 1964 */ 1965 extern struct task_struct *find_get_task_by_vpid(pid_t nr); 1966 1967 extern int wake_up_state(struct task_struct *tsk, unsigned int state); 1968 extern int wake_up_process(struct task_struct *tsk); 1969 extern void wake_up_new_task(struct task_struct *tsk); 1970 1971 #ifdef CONFIG_SMP 1972 extern void kick_process(struct task_struct *tsk); 1973 #else 1974 static inline void kick_process(struct task_struct *tsk) { } 1975 #endif 1976 1977 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec); 1978 1979 static inline void set_task_comm(struct task_struct *tsk, const char *from) 1980 { 1981 __set_task_comm(tsk, from, false); 1982 } 1983 1984 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk); 1985 #define get_task_comm(buf, tsk) ({ \ 1986 BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN); \ 1987 __get_task_comm(buf, sizeof(buf), tsk); \ 1988 }) 1989 1990 #ifdef CONFIG_SMP 1991 static __always_inline void scheduler_ipi(void) 1992 { 1993 /* 1994 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting 1995 * TIF_NEED_RESCHED remotely (for the first time) will also send 1996 * this IPI. 1997 */ 1998 preempt_fold_need_resched(); 1999 } 2000 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state); 2001 #else 2002 static inline void scheduler_ipi(void) { } 2003 static inline unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state) 2004 { 2005 return 1; 2006 } 2007 #endif 2008 2009 /* 2010 * Set thread flags in other task's structures. 2011 * See asm/thread_info.h for TIF_xxxx flags available: 2012 */ 2013 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag) 2014 { 2015 set_ti_thread_flag(task_thread_info(tsk), flag); 2016 } 2017 2018 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag) 2019 { 2020 clear_ti_thread_flag(task_thread_info(tsk), flag); 2021 } 2022 2023 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag, 2024 bool value) 2025 { 2026 update_ti_thread_flag(task_thread_info(tsk), flag, value); 2027 } 2028 2029 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag) 2030 { 2031 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag); 2032 } 2033 2034 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag) 2035 { 2036 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag); 2037 } 2038 2039 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag) 2040 { 2041 return test_ti_thread_flag(task_thread_info(tsk), flag); 2042 } 2043 2044 static inline void set_tsk_need_resched(struct task_struct *tsk) 2045 { 2046 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 2047 } 2048 2049 static inline void clear_tsk_need_resched(struct task_struct *tsk) 2050 { 2051 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 2052 } 2053 2054 static inline int test_tsk_need_resched(struct task_struct *tsk) 2055 { 2056 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED)); 2057 } 2058 2059 /* 2060 * cond_resched() and cond_resched_lock(): latency reduction via 2061 * explicit rescheduling in places that are safe. The return 2062 * value indicates whether a reschedule was done in fact. 2063 * cond_resched_lock() will drop the spinlock before scheduling, 2064 */ 2065 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) 2066 extern int __cond_resched(void); 2067 2068 #if defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL) 2069 2070 DECLARE_STATIC_CALL(cond_resched, __cond_resched); 2071 2072 static __always_inline int _cond_resched(void) 2073 { 2074 return static_call_mod(cond_resched)(); 2075 } 2076 2077 #elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY) 2078 extern int dynamic_cond_resched(void); 2079 2080 static __always_inline int _cond_resched(void) 2081 { 2082 return dynamic_cond_resched(); 2083 } 2084 2085 #else 2086 2087 static inline int _cond_resched(void) 2088 { 2089 return __cond_resched(); 2090 } 2091 2092 #endif /* CONFIG_PREEMPT_DYNAMIC */ 2093 2094 #else 2095 2096 static inline int _cond_resched(void) { return 0; } 2097 2098 #endif /* !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) */ 2099 2100 #define cond_resched() ({ \ 2101 __might_resched(__FILE__, __LINE__, 0); \ 2102 _cond_resched(); \ 2103 }) 2104 2105 extern int __cond_resched_lock(spinlock_t *lock); 2106 extern int __cond_resched_rwlock_read(rwlock_t *lock); 2107 extern int __cond_resched_rwlock_write(rwlock_t *lock); 2108 2109 #define MIGHT_RESCHED_RCU_SHIFT 8 2110 #define MIGHT_RESCHED_PREEMPT_MASK ((1U << MIGHT_RESCHED_RCU_SHIFT) - 1) 2111 2112 #ifndef CONFIG_PREEMPT_RT 2113 /* 2114 * Non RT kernels have an elevated preempt count due to the held lock, 2115 * but are not allowed to be inside a RCU read side critical section 2116 */ 2117 # define PREEMPT_LOCK_RESCHED_OFFSETS PREEMPT_LOCK_OFFSET 2118 #else 2119 /* 2120 * spin/rw_lock() on RT implies rcu_read_lock(). The might_sleep() check in 2121 * cond_resched*lock() has to take that into account because it checks for 2122 * preempt_count() and rcu_preempt_depth(). 2123 */ 2124 # define PREEMPT_LOCK_RESCHED_OFFSETS \ 2125 (PREEMPT_LOCK_OFFSET + (1U << MIGHT_RESCHED_RCU_SHIFT)) 2126 #endif 2127 2128 #define cond_resched_lock(lock) ({ \ 2129 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2130 __cond_resched_lock(lock); \ 2131 }) 2132 2133 #define cond_resched_rwlock_read(lock) ({ \ 2134 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2135 __cond_resched_rwlock_read(lock); \ 2136 }) 2137 2138 #define cond_resched_rwlock_write(lock) ({ \ 2139 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2140 __cond_resched_rwlock_write(lock); \ 2141 }) 2142 2143 static inline void cond_resched_rcu(void) 2144 { 2145 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU) 2146 rcu_read_unlock(); 2147 cond_resched(); 2148 rcu_read_lock(); 2149 #endif 2150 } 2151 2152 #ifdef CONFIG_PREEMPT_DYNAMIC 2153 2154 extern bool preempt_model_none(void); 2155 extern bool preempt_model_voluntary(void); 2156 extern bool preempt_model_full(void); 2157 2158 #else 2159 2160 static inline bool preempt_model_none(void) 2161 { 2162 return IS_ENABLED(CONFIG_PREEMPT_NONE); 2163 } 2164 static inline bool preempt_model_voluntary(void) 2165 { 2166 return IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY); 2167 } 2168 static inline bool preempt_model_full(void) 2169 { 2170 return IS_ENABLED(CONFIG_PREEMPT); 2171 } 2172 2173 #endif 2174 2175 static inline bool preempt_model_rt(void) 2176 { 2177 return IS_ENABLED(CONFIG_PREEMPT_RT); 2178 } 2179 2180 /* 2181 * Does the preemption model allow non-cooperative preemption? 2182 * 2183 * For !CONFIG_PREEMPT_DYNAMIC kernels this is an exact match with 2184 * CONFIG_PREEMPTION; for CONFIG_PREEMPT_DYNAMIC this doesn't work as the 2185 * kernel is *built* with CONFIG_PREEMPTION=y but may run with e.g. the 2186 * PREEMPT_NONE model. 2187 */ 2188 static inline bool preempt_model_preemptible(void) 2189 { 2190 return preempt_model_full() || preempt_model_rt(); 2191 } 2192 2193 /* 2194 * Does a critical section need to be broken due to another 2195 * task waiting?: (technically does not depend on CONFIG_PREEMPTION, 2196 * but a general need for low latency) 2197 */ 2198 static inline int spin_needbreak(spinlock_t *lock) 2199 { 2200 #ifdef CONFIG_PREEMPTION 2201 return spin_is_contended(lock); 2202 #else 2203 return 0; 2204 #endif 2205 } 2206 2207 /* 2208 * Check if a rwlock is contended. 2209 * Returns non-zero if there is another task waiting on the rwlock. 2210 * Returns zero if the lock is not contended or the system / underlying 2211 * rwlock implementation does not support contention detection. 2212 * Technically does not depend on CONFIG_PREEMPTION, but a general need 2213 * for low latency. 2214 */ 2215 static inline int rwlock_needbreak(rwlock_t *lock) 2216 { 2217 #ifdef CONFIG_PREEMPTION 2218 return rwlock_is_contended(lock); 2219 #else 2220 return 0; 2221 #endif 2222 } 2223 2224 static __always_inline bool need_resched(void) 2225 { 2226 return unlikely(tif_need_resched()); 2227 } 2228 2229 /* 2230 * Wrappers for p->thread_info->cpu access. No-op on UP. 2231 */ 2232 #ifdef CONFIG_SMP 2233 2234 static inline unsigned int task_cpu(const struct task_struct *p) 2235 { 2236 return READ_ONCE(task_thread_info(p)->cpu); 2237 } 2238 2239 extern void set_task_cpu(struct task_struct *p, unsigned int cpu); 2240 2241 #else 2242 2243 static inline unsigned int task_cpu(const struct task_struct *p) 2244 { 2245 return 0; 2246 } 2247 2248 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu) 2249 { 2250 } 2251 2252 #endif /* CONFIG_SMP */ 2253 2254 extern bool sched_task_on_rq(struct task_struct *p); 2255 extern unsigned long get_wchan(struct task_struct *p); 2256 extern struct task_struct *cpu_curr_snapshot(int cpu); 2257 2258 /* 2259 * In order to reduce various lock holder preemption latencies provide an 2260 * interface to see if a vCPU is currently running or not. 2261 * 2262 * This allows us to terminate optimistic spin loops and block, analogous to 2263 * the native optimistic spin heuristic of testing if the lock owner task is 2264 * running or not. 2265 */ 2266 #ifndef vcpu_is_preempted 2267 static inline bool vcpu_is_preempted(int cpu) 2268 { 2269 return false; 2270 } 2271 #endif 2272 2273 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask); 2274 extern long sched_getaffinity(pid_t pid, struct cpumask *mask); 2275 2276 #ifndef TASK_SIZE_OF 2277 #define TASK_SIZE_OF(tsk) TASK_SIZE 2278 #endif 2279 2280 #ifdef CONFIG_SMP 2281 static inline bool owner_on_cpu(struct task_struct *owner) 2282 { 2283 /* 2284 * As lock holder preemption issue, we both skip spinning if 2285 * task is not on cpu or its cpu is preempted 2286 */ 2287 return READ_ONCE(owner->on_cpu) && !vcpu_is_preempted(task_cpu(owner)); 2288 } 2289 2290 /* Returns effective CPU energy utilization, as seen by the scheduler */ 2291 unsigned long sched_cpu_util(int cpu); 2292 #endif /* CONFIG_SMP */ 2293 2294 #ifdef CONFIG_RSEQ 2295 2296 /* 2297 * Map the event mask on the user-space ABI enum rseq_cs_flags 2298 * for direct mask checks. 2299 */ 2300 enum rseq_event_mask_bits { 2301 RSEQ_EVENT_PREEMPT_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT, 2302 RSEQ_EVENT_SIGNAL_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT, 2303 RSEQ_EVENT_MIGRATE_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT, 2304 }; 2305 2306 enum rseq_event_mask { 2307 RSEQ_EVENT_PREEMPT = (1U << RSEQ_EVENT_PREEMPT_BIT), 2308 RSEQ_EVENT_SIGNAL = (1U << RSEQ_EVENT_SIGNAL_BIT), 2309 RSEQ_EVENT_MIGRATE = (1U << RSEQ_EVENT_MIGRATE_BIT), 2310 }; 2311 2312 static inline void rseq_set_notify_resume(struct task_struct *t) 2313 { 2314 if (t->rseq) 2315 set_tsk_thread_flag(t, TIF_NOTIFY_RESUME); 2316 } 2317 2318 void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs); 2319 2320 static inline void rseq_handle_notify_resume(struct ksignal *ksig, 2321 struct pt_regs *regs) 2322 { 2323 if (current->rseq) 2324 __rseq_handle_notify_resume(ksig, regs); 2325 } 2326 2327 static inline void rseq_signal_deliver(struct ksignal *ksig, 2328 struct pt_regs *regs) 2329 { 2330 preempt_disable(); 2331 __set_bit(RSEQ_EVENT_SIGNAL_BIT, ¤t->rseq_event_mask); 2332 preempt_enable(); 2333 rseq_handle_notify_resume(ksig, regs); 2334 } 2335 2336 /* rseq_preempt() requires preemption to be disabled. */ 2337 static inline void rseq_preempt(struct task_struct *t) 2338 { 2339 __set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask); 2340 rseq_set_notify_resume(t); 2341 } 2342 2343 /* rseq_migrate() requires preemption to be disabled. */ 2344 static inline void rseq_migrate(struct task_struct *t) 2345 { 2346 __set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask); 2347 rseq_set_notify_resume(t); 2348 } 2349 2350 /* 2351 * If parent process has a registered restartable sequences area, the 2352 * child inherits. Unregister rseq for a clone with CLONE_VM set. 2353 */ 2354 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags) 2355 { 2356 if (clone_flags & CLONE_VM) { 2357 t->rseq = NULL; 2358 t->rseq_len = 0; 2359 t->rseq_sig = 0; 2360 t->rseq_event_mask = 0; 2361 } else { 2362 t->rseq = current->rseq; 2363 t->rseq_len = current->rseq_len; 2364 t->rseq_sig = current->rseq_sig; 2365 t->rseq_event_mask = current->rseq_event_mask; 2366 } 2367 } 2368 2369 static inline void rseq_execve(struct task_struct *t) 2370 { 2371 t->rseq = NULL; 2372 t->rseq_len = 0; 2373 t->rseq_sig = 0; 2374 t->rseq_event_mask = 0; 2375 } 2376 2377 #else 2378 2379 static inline void rseq_set_notify_resume(struct task_struct *t) 2380 { 2381 } 2382 static inline void rseq_handle_notify_resume(struct ksignal *ksig, 2383 struct pt_regs *regs) 2384 { 2385 } 2386 static inline void rseq_signal_deliver(struct ksignal *ksig, 2387 struct pt_regs *regs) 2388 { 2389 } 2390 static inline void rseq_preempt(struct task_struct *t) 2391 { 2392 } 2393 static inline void rseq_migrate(struct task_struct *t) 2394 { 2395 } 2396 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags) 2397 { 2398 } 2399 static inline void rseq_execve(struct task_struct *t) 2400 { 2401 } 2402 2403 #endif 2404 2405 #ifdef CONFIG_DEBUG_RSEQ 2406 2407 void rseq_syscall(struct pt_regs *regs); 2408 2409 #else 2410 2411 static inline void rseq_syscall(struct pt_regs *regs) 2412 { 2413 } 2414 2415 #endif 2416 2417 #ifdef CONFIG_SCHED_CORE 2418 extern void sched_core_free(struct task_struct *tsk); 2419 extern void sched_core_fork(struct task_struct *p); 2420 extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type, 2421 unsigned long uaddr); 2422 #else 2423 static inline void sched_core_free(struct task_struct *tsk) { } 2424 static inline void sched_core_fork(struct task_struct *p) { } 2425 #endif 2426 2427 extern void sched_set_stop_task(int cpu, struct task_struct *stop); 2428 2429 #endif 2430