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 #ifdef SPLIT_RSS_COUNTING 874 struct task_rss_stat rss_stat; 875 #endif 876 int exit_state; 877 int exit_code; 878 int exit_signal; 879 /* The signal sent when the parent dies: */ 880 int pdeath_signal; 881 /* JOBCTL_*, siglock protected: */ 882 unsigned long jobctl; 883 884 /* Used for emulating ABI behavior of previous Linux versions: */ 885 unsigned int personality; 886 887 /* Scheduler bits, serialized by scheduler locks: */ 888 unsigned sched_reset_on_fork:1; 889 unsigned sched_contributes_to_load:1; 890 unsigned sched_migrated:1; 891 #ifdef CONFIG_PSI 892 unsigned sched_psi_wake_requeue:1; 893 #endif 894 895 /* Force alignment to the next boundary: */ 896 unsigned :0; 897 898 /* Unserialized, strictly 'current' */ 899 900 /* 901 * This field must not be in the scheduler word above due to wakelist 902 * queueing no longer being serialized by p->on_cpu. However: 903 * 904 * p->XXX = X; ttwu() 905 * schedule() if (p->on_rq && ..) // false 906 * smp_mb__after_spinlock(); if (smp_load_acquire(&p->on_cpu) && //true 907 * deactivate_task() ttwu_queue_wakelist()) 908 * p->on_rq = 0; p->sched_remote_wakeup = Y; 909 * 910 * guarantees all stores of 'current' are visible before 911 * ->sched_remote_wakeup gets used, so it can be in this word. 912 */ 913 unsigned sched_remote_wakeup:1; 914 915 /* Bit to tell LSMs we're in execve(): */ 916 unsigned in_execve:1; 917 unsigned in_iowait:1; 918 #ifndef TIF_RESTORE_SIGMASK 919 unsigned restore_sigmask:1; 920 #endif 921 #ifdef CONFIG_MEMCG 922 unsigned in_user_fault:1; 923 #endif 924 #ifdef CONFIG_LRU_GEN 925 /* whether the LRU algorithm may apply to this access */ 926 unsigned in_lru_fault:1; 927 #endif 928 #ifdef CONFIG_COMPAT_BRK 929 unsigned brk_randomized:1; 930 #endif 931 #ifdef CONFIG_CGROUPS 932 /* disallow userland-initiated cgroup migration */ 933 unsigned no_cgroup_migration:1; 934 /* task is frozen/stopped (used by the cgroup freezer) */ 935 unsigned frozen:1; 936 #endif 937 #ifdef CONFIG_BLK_CGROUP 938 unsigned use_memdelay:1; 939 #endif 940 #ifdef CONFIG_PSI 941 /* Stalled due to lack of memory */ 942 unsigned in_memstall:1; 943 #endif 944 #ifdef CONFIG_PAGE_OWNER 945 /* Used by page_owner=on to detect recursion in page tracking. */ 946 unsigned in_page_owner:1; 947 #endif 948 #ifdef CONFIG_EVENTFD 949 /* Recursion prevention for eventfd_signal() */ 950 unsigned in_eventfd:1; 951 #endif 952 #ifdef CONFIG_IOMMU_SVA 953 unsigned pasid_activated:1; 954 #endif 955 #ifdef CONFIG_CPU_SUP_INTEL 956 unsigned reported_split_lock:1; 957 #endif 958 #ifdef CONFIG_TASK_DELAY_ACCT 959 /* delay due to memory thrashing */ 960 unsigned in_thrashing:1; 961 #endif 962 963 unsigned long atomic_flags; /* Flags requiring atomic access. */ 964 965 struct restart_block restart_block; 966 967 pid_t pid; 968 pid_t tgid; 969 970 #ifdef CONFIG_STACKPROTECTOR 971 /* Canary value for the -fstack-protector GCC feature: */ 972 unsigned long stack_canary; 973 #endif 974 /* 975 * Pointers to the (original) parent process, youngest child, younger sibling, 976 * older sibling, respectively. (p->father can be replaced with 977 * p->real_parent->pid) 978 */ 979 980 /* Real parent process: */ 981 struct task_struct __rcu *real_parent; 982 983 /* Recipient of SIGCHLD, wait4() reports: */ 984 struct task_struct __rcu *parent; 985 986 /* 987 * Children/sibling form the list of natural children: 988 */ 989 struct list_head children; 990 struct list_head sibling; 991 struct task_struct *group_leader; 992 993 /* 994 * 'ptraced' is the list of tasks this task is using ptrace() on. 995 * 996 * This includes both natural children and PTRACE_ATTACH targets. 997 * 'ptrace_entry' is this task's link on the p->parent->ptraced list. 998 */ 999 struct list_head ptraced; 1000 struct list_head ptrace_entry; 1001 1002 /* PID/PID hash table linkage. */ 1003 struct pid *thread_pid; 1004 struct hlist_node pid_links[PIDTYPE_MAX]; 1005 struct list_head thread_group; 1006 struct list_head thread_node; 1007 1008 struct completion *vfork_done; 1009 1010 /* CLONE_CHILD_SETTID: */ 1011 int __user *set_child_tid; 1012 1013 /* CLONE_CHILD_CLEARTID: */ 1014 int __user *clear_child_tid; 1015 1016 /* PF_KTHREAD | PF_IO_WORKER */ 1017 void *worker_private; 1018 1019 u64 utime; 1020 u64 stime; 1021 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME 1022 u64 utimescaled; 1023 u64 stimescaled; 1024 #endif 1025 u64 gtime; 1026 struct prev_cputime prev_cputime; 1027 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN 1028 struct vtime vtime; 1029 #endif 1030 1031 #ifdef CONFIG_NO_HZ_FULL 1032 atomic_t tick_dep_mask; 1033 #endif 1034 /* Context switch counts: */ 1035 unsigned long nvcsw; 1036 unsigned long nivcsw; 1037 1038 /* Monotonic time in nsecs: */ 1039 u64 start_time; 1040 1041 /* Boot based time in nsecs: */ 1042 u64 start_boottime; 1043 1044 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */ 1045 unsigned long min_flt; 1046 unsigned long maj_flt; 1047 1048 /* Empty if CONFIG_POSIX_CPUTIMERS=n */ 1049 struct posix_cputimers posix_cputimers; 1050 1051 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK 1052 struct posix_cputimers_work posix_cputimers_work; 1053 #endif 1054 1055 /* Process credentials: */ 1056 1057 /* Tracer's credentials at attach: */ 1058 const struct cred __rcu *ptracer_cred; 1059 1060 /* Objective and real subjective task credentials (COW): */ 1061 const struct cred __rcu *real_cred; 1062 1063 /* Effective (overridable) subjective task credentials (COW): */ 1064 const struct cred __rcu *cred; 1065 1066 #ifdef CONFIG_KEYS 1067 /* Cached requested key. */ 1068 struct key *cached_requested_key; 1069 #endif 1070 1071 /* 1072 * executable name, excluding path. 1073 * 1074 * - normally initialized setup_new_exec() 1075 * - access it with [gs]et_task_comm() 1076 * - lock it with task_lock() 1077 */ 1078 char comm[TASK_COMM_LEN]; 1079 1080 struct nameidata *nameidata; 1081 1082 #ifdef CONFIG_SYSVIPC 1083 struct sysv_sem sysvsem; 1084 struct sysv_shm sysvshm; 1085 #endif 1086 #ifdef CONFIG_DETECT_HUNG_TASK 1087 unsigned long last_switch_count; 1088 unsigned long last_switch_time; 1089 #endif 1090 /* Filesystem information: */ 1091 struct fs_struct *fs; 1092 1093 /* Open file information: */ 1094 struct files_struct *files; 1095 1096 #ifdef CONFIG_IO_URING 1097 struct io_uring_task *io_uring; 1098 #endif 1099 1100 /* Namespaces: */ 1101 struct nsproxy *nsproxy; 1102 1103 /* Signal handlers: */ 1104 struct signal_struct *signal; 1105 struct sighand_struct __rcu *sighand; 1106 sigset_t blocked; 1107 sigset_t real_blocked; 1108 /* Restored if set_restore_sigmask() was used: */ 1109 sigset_t saved_sigmask; 1110 struct sigpending pending; 1111 unsigned long sas_ss_sp; 1112 size_t sas_ss_size; 1113 unsigned int sas_ss_flags; 1114 1115 struct callback_head *task_works; 1116 1117 #ifdef CONFIG_AUDIT 1118 #ifdef CONFIG_AUDITSYSCALL 1119 struct audit_context *audit_context; 1120 #endif 1121 kuid_t loginuid; 1122 unsigned int sessionid; 1123 #endif 1124 struct seccomp seccomp; 1125 struct syscall_user_dispatch syscall_dispatch; 1126 1127 /* Thread group tracking: */ 1128 u64 parent_exec_id; 1129 u64 self_exec_id; 1130 1131 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */ 1132 spinlock_t alloc_lock; 1133 1134 /* Protection of the PI data structures: */ 1135 raw_spinlock_t pi_lock; 1136 1137 struct wake_q_node wake_q; 1138 1139 #ifdef CONFIG_RT_MUTEXES 1140 /* PI waiters blocked on a rt_mutex held by this task: */ 1141 struct rb_root_cached pi_waiters; 1142 /* Updated under owner's pi_lock and rq lock */ 1143 struct task_struct *pi_top_task; 1144 /* Deadlock detection and priority inheritance handling: */ 1145 struct rt_mutex_waiter *pi_blocked_on; 1146 #endif 1147 1148 #ifdef CONFIG_DEBUG_MUTEXES 1149 /* Mutex deadlock detection: */ 1150 struct mutex_waiter *blocked_on; 1151 #endif 1152 1153 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1154 int non_block_count; 1155 #endif 1156 1157 #ifdef CONFIG_TRACE_IRQFLAGS 1158 struct irqtrace_events irqtrace; 1159 unsigned int hardirq_threaded; 1160 u64 hardirq_chain_key; 1161 int softirqs_enabled; 1162 int softirq_context; 1163 int irq_config; 1164 #endif 1165 #ifdef CONFIG_PREEMPT_RT 1166 int softirq_disable_cnt; 1167 #endif 1168 1169 #ifdef CONFIG_LOCKDEP 1170 # define MAX_LOCK_DEPTH 48UL 1171 u64 curr_chain_key; 1172 int lockdep_depth; 1173 unsigned int lockdep_recursion; 1174 struct held_lock held_locks[MAX_LOCK_DEPTH]; 1175 #endif 1176 1177 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP) 1178 unsigned int in_ubsan; 1179 #endif 1180 1181 /* Journalling filesystem info: */ 1182 void *journal_info; 1183 1184 /* Stacked block device info: */ 1185 struct bio_list *bio_list; 1186 1187 /* Stack plugging: */ 1188 struct blk_plug *plug; 1189 1190 /* VM state: */ 1191 struct reclaim_state *reclaim_state; 1192 1193 struct backing_dev_info *backing_dev_info; 1194 1195 struct io_context *io_context; 1196 1197 #ifdef CONFIG_COMPACTION 1198 struct capture_control *capture_control; 1199 #endif 1200 /* Ptrace state: */ 1201 unsigned long ptrace_message; 1202 kernel_siginfo_t *last_siginfo; 1203 1204 struct task_io_accounting ioac; 1205 #ifdef CONFIG_PSI 1206 /* Pressure stall state */ 1207 unsigned int psi_flags; 1208 #endif 1209 #ifdef CONFIG_TASK_XACCT 1210 /* Accumulated RSS usage: */ 1211 u64 acct_rss_mem1; 1212 /* Accumulated virtual memory usage: */ 1213 u64 acct_vm_mem1; 1214 /* stime + utime since last update: */ 1215 u64 acct_timexpd; 1216 #endif 1217 #ifdef CONFIG_CPUSETS 1218 /* Protected by ->alloc_lock: */ 1219 nodemask_t mems_allowed; 1220 /* Sequence number to catch updates: */ 1221 seqcount_spinlock_t mems_allowed_seq; 1222 int cpuset_mem_spread_rotor; 1223 int cpuset_slab_spread_rotor; 1224 #endif 1225 #ifdef CONFIG_CGROUPS 1226 /* Control Group info protected by css_set_lock: */ 1227 struct css_set __rcu *cgroups; 1228 /* cg_list protected by css_set_lock and tsk->alloc_lock: */ 1229 struct list_head cg_list; 1230 #endif 1231 #ifdef CONFIG_X86_CPU_RESCTRL 1232 u32 closid; 1233 u32 rmid; 1234 #endif 1235 #ifdef CONFIG_FUTEX 1236 struct robust_list_head __user *robust_list; 1237 #ifdef CONFIG_COMPAT 1238 struct compat_robust_list_head __user *compat_robust_list; 1239 #endif 1240 struct list_head pi_state_list; 1241 struct futex_pi_state *pi_state_cache; 1242 struct mutex futex_exit_mutex; 1243 unsigned int futex_state; 1244 #endif 1245 #ifdef CONFIG_PERF_EVENTS 1246 struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts]; 1247 struct mutex perf_event_mutex; 1248 struct list_head perf_event_list; 1249 #endif 1250 #ifdef CONFIG_DEBUG_PREEMPT 1251 unsigned long preempt_disable_ip; 1252 #endif 1253 #ifdef CONFIG_NUMA 1254 /* Protected by alloc_lock: */ 1255 struct mempolicy *mempolicy; 1256 short il_prev; 1257 short pref_node_fork; 1258 #endif 1259 #ifdef CONFIG_NUMA_BALANCING 1260 int numa_scan_seq; 1261 unsigned int numa_scan_period; 1262 unsigned int numa_scan_period_max; 1263 int numa_preferred_nid; 1264 unsigned long numa_migrate_retry; 1265 /* Migration stamp: */ 1266 u64 node_stamp; 1267 u64 last_task_numa_placement; 1268 u64 last_sum_exec_runtime; 1269 struct callback_head numa_work; 1270 1271 /* 1272 * This pointer is only modified for current in syscall and 1273 * pagefault context (and for tasks being destroyed), so it can be read 1274 * from any of the following contexts: 1275 * - RCU read-side critical section 1276 * - current->numa_group from everywhere 1277 * - task's runqueue locked, task not running 1278 */ 1279 struct numa_group __rcu *numa_group; 1280 1281 /* 1282 * numa_faults is an array split into four regions: 1283 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer 1284 * in this precise order. 1285 * 1286 * faults_memory: Exponential decaying average of faults on a per-node 1287 * basis. Scheduling placement decisions are made based on these 1288 * counts. The values remain static for the duration of a PTE scan. 1289 * faults_cpu: Track the nodes the process was running on when a NUMA 1290 * hinting fault was incurred. 1291 * faults_memory_buffer and faults_cpu_buffer: Record faults per node 1292 * during the current scan window. When the scan completes, the counts 1293 * in faults_memory and faults_cpu decay and these values are copied. 1294 */ 1295 unsigned long *numa_faults; 1296 unsigned long total_numa_faults; 1297 1298 /* 1299 * numa_faults_locality tracks if faults recorded during the last 1300 * scan window were remote/local or failed to migrate. The task scan 1301 * period is adapted based on the locality of the faults with different 1302 * weights depending on whether they were shared or private faults 1303 */ 1304 unsigned long numa_faults_locality[3]; 1305 1306 unsigned long numa_pages_migrated; 1307 #endif /* CONFIG_NUMA_BALANCING */ 1308 1309 #ifdef CONFIG_RSEQ 1310 struct rseq __user *rseq; 1311 u32 rseq_sig; 1312 /* 1313 * RmW on rseq_event_mask must be performed atomically 1314 * with respect to preemption. 1315 */ 1316 unsigned long rseq_event_mask; 1317 #endif 1318 1319 struct tlbflush_unmap_batch tlb_ubc; 1320 1321 union { 1322 refcount_t rcu_users; 1323 struct rcu_head rcu; 1324 }; 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 request_queue *throttle_queue; 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 int pagefault_disabled; 1463 #ifdef CONFIG_MMU 1464 struct task_struct *oom_reaper_list; 1465 struct timer_list oom_reaper_timer; 1466 #endif 1467 #ifdef CONFIG_VMAP_STACK 1468 struct vm_struct *stack_vm_area; 1469 #endif 1470 #ifdef CONFIG_THREAD_INFO_IN_TASK 1471 /* A live task holds one reference: */ 1472 refcount_t stack_refcount; 1473 #endif 1474 #ifdef CONFIG_LIVEPATCH 1475 int patch_state; 1476 #endif 1477 #ifdef CONFIG_SECURITY 1478 /* Used by LSM modules for access restriction: */ 1479 void *security; 1480 #endif 1481 #ifdef CONFIG_BPF_SYSCALL 1482 /* Used by BPF task local storage */ 1483 struct bpf_local_storage __rcu *bpf_storage; 1484 /* Used for BPF run context */ 1485 struct bpf_run_ctx *bpf_ctx; 1486 #endif 1487 1488 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK 1489 unsigned long lowest_stack; 1490 unsigned long prev_lowest_stack; 1491 #endif 1492 1493 #ifdef CONFIG_X86_MCE 1494 void __user *mce_vaddr; 1495 __u64 mce_kflags; 1496 u64 mce_addr; 1497 __u64 mce_ripv : 1, 1498 mce_whole_page : 1, 1499 __mce_reserved : 62; 1500 struct callback_head mce_kill_me; 1501 int mce_count; 1502 #endif 1503 1504 #ifdef CONFIG_KRETPROBES 1505 struct llist_head kretprobe_instances; 1506 #endif 1507 #ifdef CONFIG_RETHOOK 1508 struct llist_head rethooks; 1509 #endif 1510 1511 #ifdef CONFIG_ARCH_HAS_PARANOID_L1D_FLUSH 1512 /* 1513 * If L1D flush is supported on mm context switch 1514 * then we use this callback head to queue kill work 1515 * to kill tasks that are not running on SMT disabled 1516 * cores 1517 */ 1518 struct callback_head l1d_flush_kill; 1519 #endif 1520 1521 #ifdef CONFIG_RV 1522 /* 1523 * Per-task RV monitor. Nowadays fixed in RV_PER_TASK_MONITORS. 1524 * If we find justification for more monitors, we can think 1525 * about adding more or developing a dynamic method. So far, 1526 * none of these are justified. 1527 */ 1528 union rv_task_monitor rv[RV_PER_TASK_MONITORS]; 1529 #endif 1530 1531 /* 1532 * New fields for task_struct should be added above here, so that 1533 * they are included in the randomized portion of task_struct. 1534 */ 1535 randomized_struct_fields_end 1536 1537 /* CPU-specific state of this task: */ 1538 struct thread_struct thread; 1539 1540 /* 1541 * WARNING: on x86, 'thread_struct' contains a variable-sized 1542 * structure. It *MUST* be at the end of 'task_struct'. 1543 * 1544 * Do not put anything below here! 1545 */ 1546 }; 1547 1548 static inline struct pid *task_pid(struct task_struct *task) 1549 { 1550 return task->thread_pid; 1551 } 1552 1553 /* 1554 * the helpers to get the task's different pids as they are seen 1555 * from various namespaces 1556 * 1557 * task_xid_nr() : global id, i.e. the id seen from the init namespace; 1558 * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of 1559 * current. 1560 * task_xid_nr_ns() : id seen from the ns specified; 1561 * 1562 * see also pid_nr() etc in include/linux/pid.h 1563 */ 1564 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns); 1565 1566 static inline pid_t task_pid_nr(struct task_struct *tsk) 1567 { 1568 return tsk->pid; 1569 } 1570 1571 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1572 { 1573 return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns); 1574 } 1575 1576 static inline pid_t task_pid_vnr(struct task_struct *tsk) 1577 { 1578 return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL); 1579 } 1580 1581 1582 static inline pid_t task_tgid_nr(struct task_struct *tsk) 1583 { 1584 return tsk->tgid; 1585 } 1586 1587 /** 1588 * pid_alive - check that a task structure is not stale 1589 * @p: Task structure to be checked. 1590 * 1591 * Test if a process is not yet dead (at most zombie state) 1592 * If pid_alive fails, then pointers within the task structure 1593 * can be stale and must not be dereferenced. 1594 * 1595 * Return: 1 if the process is alive. 0 otherwise. 1596 */ 1597 static inline int pid_alive(const struct task_struct *p) 1598 { 1599 return p->thread_pid != NULL; 1600 } 1601 1602 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1603 { 1604 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns); 1605 } 1606 1607 static inline pid_t task_pgrp_vnr(struct task_struct *tsk) 1608 { 1609 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL); 1610 } 1611 1612 1613 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1614 { 1615 return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns); 1616 } 1617 1618 static inline pid_t task_session_vnr(struct task_struct *tsk) 1619 { 1620 return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL); 1621 } 1622 1623 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1624 { 1625 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, ns); 1626 } 1627 1628 static inline pid_t task_tgid_vnr(struct task_struct *tsk) 1629 { 1630 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, NULL); 1631 } 1632 1633 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns) 1634 { 1635 pid_t pid = 0; 1636 1637 rcu_read_lock(); 1638 if (pid_alive(tsk)) 1639 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns); 1640 rcu_read_unlock(); 1641 1642 return pid; 1643 } 1644 1645 static inline pid_t task_ppid_nr(const struct task_struct *tsk) 1646 { 1647 return task_ppid_nr_ns(tsk, &init_pid_ns); 1648 } 1649 1650 /* Obsolete, do not use: */ 1651 static inline pid_t task_pgrp_nr(struct task_struct *tsk) 1652 { 1653 return task_pgrp_nr_ns(tsk, &init_pid_ns); 1654 } 1655 1656 #define TASK_REPORT_IDLE (TASK_REPORT + 1) 1657 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1) 1658 1659 static inline unsigned int __task_state_index(unsigned int tsk_state, 1660 unsigned int tsk_exit_state) 1661 { 1662 unsigned int state = (tsk_state | tsk_exit_state) & TASK_REPORT; 1663 1664 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX); 1665 1666 if (tsk_state == TASK_IDLE) 1667 state = TASK_REPORT_IDLE; 1668 1669 /* 1670 * We're lying here, but rather than expose a completely new task state 1671 * to userspace, we can make this appear as if the task has gone through 1672 * a regular rt_mutex_lock() call. 1673 */ 1674 if (tsk_state == TASK_RTLOCK_WAIT) 1675 state = TASK_UNINTERRUPTIBLE; 1676 1677 return fls(state); 1678 } 1679 1680 static inline unsigned int task_state_index(struct task_struct *tsk) 1681 { 1682 return __task_state_index(READ_ONCE(tsk->__state), tsk->exit_state); 1683 } 1684 1685 static inline char task_index_to_char(unsigned int state) 1686 { 1687 static const char state_char[] = "RSDTtXZPI"; 1688 1689 BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1); 1690 1691 return state_char[state]; 1692 } 1693 1694 static inline char task_state_to_char(struct task_struct *tsk) 1695 { 1696 return task_index_to_char(task_state_index(tsk)); 1697 } 1698 1699 /** 1700 * is_global_init - check if a task structure is init. Since init 1701 * is free to have sub-threads we need to check tgid. 1702 * @tsk: Task structure to be checked. 1703 * 1704 * Check if a task structure is the first user space task the kernel created. 1705 * 1706 * Return: 1 if the task structure is init. 0 otherwise. 1707 */ 1708 static inline int is_global_init(struct task_struct *tsk) 1709 { 1710 return task_tgid_nr(tsk) == 1; 1711 } 1712 1713 extern struct pid *cad_pid; 1714 1715 /* 1716 * Per process flags 1717 */ 1718 #define PF_VCPU 0x00000001 /* I'm a virtual CPU */ 1719 #define PF_IDLE 0x00000002 /* I am an IDLE thread */ 1720 #define PF_EXITING 0x00000004 /* Getting shut down */ 1721 #define PF_POSTCOREDUMP 0x00000008 /* Coredumps should ignore this task */ 1722 #define PF_IO_WORKER 0x00000010 /* Task is an IO worker */ 1723 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */ 1724 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */ 1725 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */ 1726 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */ 1727 #define PF_DUMPCORE 0x00000200 /* Dumped core */ 1728 #define PF_SIGNALED 0x00000400 /* Killed by a signal */ 1729 #define PF_MEMALLOC 0x00000800 /* Allocating memory */ 1730 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */ 1731 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */ 1732 #define PF__HOLE__00004000 0x00004000 1733 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */ 1734 #define PF__HOLE__00010000 0x00010000 1735 #define PF_KSWAPD 0x00020000 /* I am kswapd */ 1736 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocation requests will inherit GFP_NOFS */ 1737 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocation requests will inherit GFP_NOIO */ 1738 #define PF_LOCAL_THROTTLE 0x00100000 /* Throttle writes only against the bdi I write to, 1739 * I am cleaning dirty pages from some other bdi. */ 1740 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */ 1741 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */ 1742 #define PF__HOLE__00800000 0x00800000 1743 #define PF__HOLE__01000000 0x01000000 1744 #define PF__HOLE__02000000 0x02000000 1745 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */ 1746 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */ 1747 #define PF_MEMALLOC_PIN 0x10000000 /* Allocation context constrained to zones which allow long term pinning. */ 1748 #define PF__HOLE__20000000 0x20000000 1749 #define PF__HOLE__40000000 0x40000000 1750 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */ 1751 1752 /* 1753 * Only the _current_ task can read/write to tsk->flags, but other 1754 * tasks can access tsk->flags in readonly mode for example 1755 * with tsk_used_math (like during threaded core dumping). 1756 * There is however an exception to this rule during ptrace 1757 * or during fork: the ptracer task is allowed to write to the 1758 * child->flags of its traced child (same goes for fork, the parent 1759 * can write to the child->flags), because we're guaranteed the 1760 * child is not running and in turn not changing child->flags 1761 * at the same time the parent does it. 1762 */ 1763 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0) 1764 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0) 1765 #define clear_used_math() clear_stopped_child_used_math(current) 1766 #define set_used_math() set_stopped_child_used_math(current) 1767 1768 #define conditional_stopped_child_used_math(condition, child) \ 1769 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0) 1770 1771 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current) 1772 1773 #define copy_to_stopped_child_used_math(child) \ 1774 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0) 1775 1776 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */ 1777 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH) 1778 #define used_math() tsk_used_math(current) 1779 1780 static __always_inline bool is_percpu_thread(void) 1781 { 1782 #ifdef CONFIG_SMP 1783 return (current->flags & PF_NO_SETAFFINITY) && 1784 (current->nr_cpus_allowed == 1); 1785 #else 1786 return true; 1787 #endif 1788 } 1789 1790 /* Per-process atomic flags. */ 1791 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */ 1792 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */ 1793 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */ 1794 #define PFA_SPEC_SSB_DISABLE 3 /* Speculative Store Bypass disabled */ 1795 #define PFA_SPEC_SSB_FORCE_DISABLE 4 /* Speculative Store Bypass force disabled*/ 1796 #define PFA_SPEC_IB_DISABLE 5 /* Indirect branch speculation restricted */ 1797 #define PFA_SPEC_IB_FORCE_DISABLE 6 /* Indirect branch speculation permanently restricted */ 1798 #define PFA_SPEC_SSB_NOEXEC 7 /* Speculative Store Bypass clear on execve() */ 1799 1800 #define TASK_PFA_TEST(name, func) \ 1801 static inline bool task_##func(struct task_struct *p) \ 1802 { return test_bit(PFA_##name, &p->atomic_flags); } 1803 1804 #define TASK_PFA_SET(name, func) \ 1805 static inline void task_set_##func(struct task_struct *p) \ 1806 { set_bit(PFA_##name, &p->atomic_flags); } 1807 1808 #define TASK_PFA_CLEAR(name, func) \ 1809 static inline void task_clear_##func(struct task_struct *p) \ 1810 { clear_bit(PFA_##name, &p->atomic_flags); } 1811 1812 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs) 1813 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs) 1814 1815 TASK_PFA_TEST(SPREAD_PAGE, spread_page) 1816 TASK_PFA_SET(SPREAD_PAGE, spread_page) 1817 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page) 1818 1819 TASK_PFA_TEST(SPREAD_SLAB, spread_slab) 1820 TASK_PFA_SET(SPREAD_SLAB, spread_slab) 1821 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab) 1822 1823 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable) 1824 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable) 1825 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable) 1826 1827 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1828 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1829 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1830 1831 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1832 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1833 1834 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable) 1835 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable) 1836 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable) 1837 1838 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1839 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1840 1841 static inline void 1842 current_restore_flags(unsigned long orig_flags, unsigned long flags) 1843 { 1844 current->flags &= ~flags; 1845 current->flags |= orig_flags & flags; 1846 } 1847 1848 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial); 1849 extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_effective_cpus); 1850 #ifdef CONFIG_SMP 1851 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask); 1852 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask); 1853 extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node); 1854 extern void release_user_cpus_ptr(struct task_struct *p); 1855 extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask); 1856 extern void force_compatible_cpus_allowed_ptr(struct task_struct *p); 1857 extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p); 1858 #else 1859 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) 1860 { 1861 } 1862 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) 1863 { 1864 if (!cpumask_test_cpu(0, new_mask)) 1865 return -EINVAL; 1866 return 0; 1867 } 1868 static inline int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node) 1869 { 1870 if (src->user_cpus_ptr) 1871 return -EINVAL; 1872 return 0; 1873 } 1874 static inline void release_user_cpus_ptr(struct task_struct *p) 1875 { 1876 WARN_ON(p->user_cpus_ptr); 1877 } 1878 1879 static inline int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask) 1880 { 1881 return 0; 1882 } 1883 #endif 1884 1885 extern int yield_to(struct task_struct *p, bool preempt); 1886 extern void set_user_nice(struct task_struct *p, long nice); 1887 extern int task_prio(const struct task_struct *p); 1888 1889 /** 1890 * task_nice - return the nice value of a given task. 1891 * @p: the task in question. 1892 * 1893 * Return: The nice value [ -20 ... 0 ... 19 ]. 1894 */ 1895 static inline int task_nice(const struct task_struct *p) 1896 { 1897 return PRIO_TO_NICE((p)->static_prio); 1898 } 1899 1900 extern int can_nice(const struct task_struct *p, const int nice); 1901 extern int task_curr(const struct task_struct *p); 1902 extern int idle_cpu(int cpu); 1903 extern int available_idle_cpu(int cpu); 1904 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *); 1905 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *); 1906 extern void sched_set_fifo(struct task_struct *p); 1907 extern void sched_set_fifo_low(struct task_struct *p); 1908 extern void sched_set_normal(struct task_struct *p, int nice); 1909 extern int sched_setattr(struct task_struct *, const struct sched_attr *); 1910 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *); 1911 extern struct task_struct *idle_task(int cpu); 1912 1913 /** 1914 * is_idle_task - is the specified task an idle task? 1915 * @p: the task in question. 1916 * 1917 * Return: 1 if @p is an idle task. 0 otherwise. 1918 */ 1919 static __always_inline bool is_idle_task(const struct task_struct *p) 1920 { 1921 return !!(p->flags & PF_IDLE); 1922 } 1923 1924 extern struct task_struct *curr_task(int cpu); 1925 extern void ia64_set_curr_task(int cpu, struct task_struct *p); 1926 1927 void yield(void); 1928 1929 union thread_union { 1930 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK 1931 struct task_struct task; 1932 #endif 1933 #ifndef CONFIG_THREAD_INFO_IN_TASK 1934 struct thread_info thread_info; 1935 #endif 1936 unsigned long stack[THREAD_SIZE/sizeof(long)]; 1937 }; 1938 1939 #ifndef CONFIG_THREAD_INFO_IN_TASK 1940 extern struct thread_info init_thread_info; 1941 #endif 1942 1943 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)]; 1944 1945 #ifdef CONFIG_THREAD_INFO_IN_TASK 1946 # define task_thread_info(task) (&(task)->thread_info) 1947 #elif !defined(__HAVE_THREAD_FUNCTIONS) 1948 # define task_thread_info(task) ((struct thread_info *)(task)->stack) 1949 #endif 1950 1951 /* 1952 * find a task by one of its numerical ids 1953 * 1954 * find_task_by_pid_ns(): 1955 * finds a task by its pid in the specified namespace 1956 * find_task_by_vpid(): 1957 * finds a task by its virtual pid 1958 * 1959 * see also find_vpid() etc in include/linux/pid.h 1960 */ 1961 1962 extern struct task_struct *find_task_by_vpid(pid_t nr); 1963 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns); 1964 1965 /* 1966 * find a task by its virtual pid and get the task struct 1967 */ 1968 extern struct task_struct *find_get_task_by_vpid(pid_t nr); 1969 1970 extern int wake_up_state(struct task_struct *tsk, unsigned int state); 1971 extern int wake_up_process(struct task_struct *tsk); 1972 extern void wake_up_new_task(struct task_struct *tsk); 1973 1974 #ifdef CONFIG_SMP 1975 extern void kick_process(struct task_struct *tsk); 1976 #else 1977 static inline void kick_process(struct task_struct *tsk) { } 1978 #endif 1979 1980 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec); 1981 1982 static inline void set_task_comm(struct task_struct *tsk, const char *from) 1983 { 1984 __set_task_comm(tsk, from, false); 1985 } 1986 1987 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk); 1988 #define get_task_comm(buf, tsk) ({ \ 1989 BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN); \ 1990 __get_task_comm(buf, sizeof(buf), tsk); \ 1991 }) 1992 1993 #ifdef CONFIG_SMP 1994 static __always_inline void scheduler_ipi(void) 1995 { 1996 /* 1997 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting 1998 * TIF_NEED_RESCHED remotely (for the first time) will also send 1999 * this IPI. 2000 */ 2001 preempt_fold_need_resched(); 2002 } 2003 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state); 2004 #else 2005 static inline void scheduler_ipi(void) { } 2006 static inline unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state) 2007 { 2008 return 1; 2009 } 2010 #endif 2011 2012 /* 2013 * Set thread flags in other task's structures. 2014 * See asm/thread_info.h for TIF_xxxx flags available: 2015 */ 2016 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag) 2017 { 2018 set_ti_thread_flag(task_thread_info(tsk), flag); 2019 } 2020 2021 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag) 2022 { 2023 clear_ti_thread_flag(task_thread_info(tsk), flag); 2024 } 2025 2026 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag, 2027 bool value) 2028 { 2029 update_ti_thread_flag(task_thread_info(tsk), flag, value); 2030 } 2031 2032 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag) 2033 { 2034 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag); 2035 } 2036 2037 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag) 2038 { 2039 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag); 2040 } 2041 2042 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag) 2043 { 2044 return test_ti_thread_flag(task_thread_info(tsk), flag); 2045 } 2046 2047 static inline void set_tsk_need_resched(struct task_struct *tsk) 2048 { 2049 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 2050 } 2051 2052 static inline void clear_tsk_need_resched(struct task_struct *tsk) 2053 { 2054 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 2055 } 2056 2057 static inline int test_tsk_need_resched(struct task_struct *tsk) 2058 { 2059 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED)); 2060 } 2061 2062 /* 2063 * cond_resched() and cond_resched_lock(): latency reduction via 2064 * explicit rescheduling in places that are safe. The return 2065 * value indicates whether a reschedule was done in fact. 2066 * cond_resched_lock() will drop the spinlock before scheduling, 2067 */ 2068 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) 2069 extern int __cond_resched(void); 2070 2071 #if defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL) 2072 2073 DECLARE_STATIC_CALL(cond_resched, __cond_resched); 2074 2075 static __always_inline int _cond_resched(void) 2076 { 2077 return static_call_mod(cond_resched)(); 2078 } 2079 2080 #elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY) 2081 extern int dynamic_cond_resched(void); 2082 2083 static __always_inline int _cond_resched(void) 2084 { 2085 return dynamic_cond_resched(); 2086 } 2087 2088 #else 2089 2090 static inline int _cond_resched(void) 2091 { 2092 return __cond_resched(); 2093 } 2094 2095 #endif /* CONFIG_PREEMPT_DYNAMIC */ 2096 2097 #else 2098 2099 static inline int _cond_resched(void) { return 0; } 2100 2101 #endif /* !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) */ 2102 2103 #define cond_resched() ({ \ 2104 __might_resched(__FILE__, __LINE__, 0); \ 2105 _cond_resched(); \ 2106 }) 2107 2108 extern int __cond_resched_lock(spinlock_t *lock); 2109 extern int __cond_resched_rwlock_read(rwlock_t *lock); 2110 extern int __cond_resched_rwlock_write(rwlock_t *lock); 2111 2112 #define MIGHT_RESCHED_RCU_SHIFT 8 2113 #define MIGHT_RESCHED_PREEMPT_MASK ((1U << MIGHT_RESCHED_RCU_SHIFT) - 1) 2114 2115 #ifndef CONFIG_PREEMPT_RT 2116 /* 2117 * Non RT kernels have an elevated preempt count due to the held lock, 2118 * but are not allowed to be inside a RCU read side critical section 2119 */ 2120 # define PREEMPT_LOCK_RESCHED_OFFSETS PREEMPT_LOCK_OFFSET 2121 #else 2122 /* 2123 * spin/rw_lock() on RT implies rcu_read_lock(). The might_sleep() check in 2124 * cond_resched*lock() has to take that into account because it checks for 2125 * preempt_count() and rcu_preempt_depth(). 2126 */ 2127 # define PREEMPT_LOCK_RESCHED_OFFSETS \ 2128 (PREEMPT_LOCK_OFFSET + (1U << MIGHT_RESCHED_RCU_SHIFT)) 2129 #endif 2130 2131 #define cond_resched_lock(lock) ({ \ 2132 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2133 __cond_resched_lock(lock); \ 2134 }) 2135 2136 #define cond_resched_rwlock_read(lock) ({ \ 2137 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2138 __cond_resched_rwlock_read(lock); \ 2139 }) 2140 2141 #define cond_resched_rwlock_write(lock) ({ \ 2142 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2143 __cond_resched_rwlock_write(lock); \ 2144 }) 2145 2146 static inline void cond_resched_rcu(void) 2147 { 2148 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU) 2149 rcu_read_unlock(); 2150 cond_resched(); 2151 rcu_read_lock(); 2152 #endif 2153 } 2154 2155 #ifdef CONFIG_PREEMPT_DYNAMIC 2156 2157 extern bool preempt_model_none(void); 2158 extern bool preempt_model_voluntary(void); 2159 extern bool preempt_model_full(void); 2160 2161 #else 2162 2163 static inline bool preempt_model_none(void) 2164 { 2165 return IS_ENABLED(CONFIG_PREEMPT_NONE); 2166 } 2167 static inline bool preempt_model_voluntary(void) 2168 { 2169 return IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY); 2170 } 2171 static inline bool preempt_model_full(void) 2172 { 2173 return IS_ENABLED(CONFIG_PREEMPT); 2174 } 2175 2176 #endif 2177 2178 static inline bool preempt_model_rt(void) 2179 { 2180 return IS_ENABLED(CONFIG_PREEMPT_RT); 2181 } 2182 2183 /* 2184 * Does the preemption model allow non-cooperative preemption? 2185 * 2186 * For !CONFIG_PREEMPT_DYNAMIC kernels this is an exact match with 2187 * CONFIG_PREEMPTION; for CONFIG_PREEMPT_DYNAMIC this doesn't work as the 2188 * kernel is *built* with CONFIG_PREEMPTION=y but may run with e.g. the 2189 * PREEMPT_NONE model. 2190 */ 2191 static inline bool preempt_model_preemptible(void) 2192 { 2193 return preempt_model_full() || preempt_model_rt(); 2194 } 2195 2196 /* 2197 * Does a critical section need to be broken due to another 2198 * task waiting?: (technically does not depend on CONFIG_PREEMPTION, 2199 * but a general need for low latency) 2200 */ 2201 static inline int spin_needbreak(spinlock_t *lock) 2202 { 2203 #ifdef CONFIG_PREEMPTION 2204 return spin_is_contended(lock); 2205 #else 2206 return 0; 2207 #endif 2208 } 2209 2210 /* 2211 * Check if a rwlock is contended. 2212 * Returns non-zero if there is another task waiting on the rwlock. 2213 * Returns zero if the lock is not contended or the system / underlying 2214 * rwlock implementation does not support contention detection. 2215 * Technically does not depend on CONFIG_PREEMPTION, but a general need 2216 * for low latency. 2217 */ 2218 static inline int rwlock_needbreak(rwlock_t *lock) 2219 { 2220 #ifdef CONFIG_PREEMPTION 2221 return rwlock_is_contended(lock); 2222 #else 2223 return 0; 2224 #endif 2225 } 2226 2227 static __always_inline bool need_resched(void) 2228 { 2229 return unlikely(tif_need_resched()); 2230 } 2231 2232 /* 2233 * Wrappers for p->thread_info->cpu access. No-op on UP. 2234 */ 2235 #ifdef CONFIG_SMP 2236 2237 static inline unsigned int task_cpu(const struct task_struct *p) 2238 { 2239 return READ_ONCE(task_thread_info(p)->cpu); 2240 } 2241 2242 extern void set_task_cpu(struct task_struct *p, unsigned int cpu); 2243 2244 #else 2245 2246 static inline unsigned int task_cpu(const struct task_struct *p) 2247 { 2248 return 0; 2249 } 2250 2251 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu) 2252 { 2253 } 2254 2255 #endif /* CONFIG_SMP */ 2256 2257 extern bool sched_task_on_rq(struct task_struct *p); 2258 extern unsigned long get_wchan(struct task_struct *p); 2259 extern struct task_struct *cpu_curr_snapshot(int cpu); 2260 2261 /* 2262 * In order to reduce various lock holder preemption latencies provide an 2263 * interface to see if a vCPU is currently running or not. 2264 * 2265 * This allows us to terminate optimistic spin loops and block, analogous to 2266 * the native optimistic spin heuristic of testing if the lock owner task is 2267 * running or not. 2268 */ 2269 #ifndef vcpu_is_preempted 2270 static inline bool vcpu_is_preempted(int cpu) 2271 { 2272 return false; 2273 } 2274 #endif 2275 2276 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask); 2277 extern long sched_getaffinity(pid_t pid, struct cpumask *mask); 2278 2279 #ifndef TASK_SIZE_OF 2280 #define TASK_SIZE_OF(tsk) TASK_SIZE 2281 #endif 2282 2283 #ifdef CONFIG_SMP 2284 static inline bool owner_on_cpu(struct task_struct *owner) 2285 { 2286 /* 2287 * As lock holder preemption issue, we both skip spinning if 2288 * task is not on cpu or its cpu is preempted 2289 */ 2290 return READ_ONCE(owner->on_cpu) && !vcpu_is_preempted(task_cpu(owner)); 2291 } 2292 2293 /* Returns effective CPU energy utilization, as seen by the scheduler */ 2294 unsigned long sched_cpu_util(int cpu); 2295 #endif /* CONFIG_SMP */ 2296 2297 #ifdef CONFIG_RSEQ 2298 2299 /* 2300 * Map the event mask on the user-space ABI enum rseq_cs_flags 2301 * for direct mask checks. 2302 */ 2303 enum rseq_event_mask_bits { 2304 RSEQ_EVENT_PREEMPT_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT, 2305 RSEQ_EVENT_SIGNAL_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT, 2306 RSEQ_EVENT_MIGRATE_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT, 2307 }; 2308 2309 enum rseq_event_mask { 2310 RSEQ_EVENT_PREEMPT = (1U << RSEQ_EVENT_PREEMPT_BIT), 2311 RSEQ_EVENT_SIGNAL = (1U << RSEQ_EVENT_SIGNAL_BIT), 2312 RSEQ_EVENT_MIGRATE = (1U << RSEQ_EVENT_MIGRATE_BIT), 2313 }; 2314 2315 static inline void rseq_set_notify_resume(struct task_struct *t) 2316 { 2317 if (t->rseq) 2318 set_tsk_thread_flag(t, TIF_NOTIFY_RESUME); 2319 } 2320 2321 void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs); 2322 2323 static inline void rseq_handle_notify_resume(struct ksignal *ksig, 2324 struct pt_regs *regs) 2325 { 2326 if (current->rseq) 2327 __rseq_handle_notify_resume(ksig, regs); 2328 } 2329 2330 static inline void rseq_signal_deliver(struct ksignal *ksig, 2331 struct pt_regs *regs) 2332 { 2333 preempt_disable(); 2334 __set_bit(RSEQ_EVENT_SIGNAL_BIT, ¤t->rseq_event_mask); 2335 preempt_enable(); 2336 rseq_handle_notify_resume(ksig, regs); 2337 } 2338 2339 /* rseq_preempt() requires preemption to be disabled. */ 2340 static inline void rseq_preempt(struct task_struct *t) 2341 { 2342 __set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask); 2343 rseq_set_notify_resume(t); 2344 } 2345 2346 /* rseq_migrate() requires preemption to be disabled. */ 2347 static inline void rseq_migrate(struct task_struct *t) 2348 { 2349 __set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask); 2350 rseq_set_notify_resume(t); 2351 } 2352 2353 /* 2354 * If parent process has a registered restartable sequences area, the 2355 * child inherits. Unregister rseq for a clone with CLONE_VM set. 2356 */ 2357 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags) 2358 { 2359 if (clone_flags & CLONE_VM) { 2360 t->rseq = NULL; 2361 t->rseq_sig = 0; 2362 t->rseq_event_mask = 0; 2363 } else { 2364 t->rseq = current->rseq; 2365 t->rseq_sig = current->rseq_sig; 2366 t->rseq_event_mask = current->rseq_event_mask; 2367 } 2368 } 2369 2370 static inline void rseq_execve(struct task_struct *t) 2371 { 2372 t->rseq = NULL; 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