1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _LINUX_SCHED_H 3 #define _LINUX_SCHED_H 4 5 /* 6 * Define 'struct task_struct' and provide the main scheduler 7 * APIs (schedule(), wakeup variants, etc.) 8 */ 9 10 #include <uapi/linux/sched.h> 11 12 #include <asm/current.h> 13 14 #include <linux/pid.h> 15 #include <linux/sem.h> 16 #include <linux/shm.h> 17 #include <linux/kmsan_types.h> 18 #include <linux/mutex.h> 19 #include <linux/plist.h> 20 #include <linux/hrtimer.h> 21 #include <linux/irqflags.h> 22 #include <linux/seccomp.h> 23 #include <linux/nodemask.h> 24 #include <linux/rcupdate.h> 25 #include <linux/refcount.h> 26 #include <linux/resource.h> 27 #include <linux/latencytop.h> 28 #include <linux/sched/prio.h> 29 #include <linux/sched/types.h> 30 #include <linux/signal_types.h> 31 #include <linux/syscall_user_dispatch.h> 32 #include <linux/mm_types_task.h> 33 #include <linux/task_io_accounting.h> 34 #include <linux/posix-timers.h> 35 #include <linux/rseq.h> 36 #include <linux/seqlock.h> 37 #include <linux/kcsan.h> 38 #include <linux/rv.h> 39 #include <linux/livepatch_sched.h> 40 #include <asm/kmap_size.h> 41 42 /* task_struct member predeclarations (sorted alphabetically): */ 43 struct audit_context; 44 struct backing_dev_info; 45 struct bio_list; 46 struct blk_plug; 47 struct bpf_local_storage; 48 struct bpf_run_ctx; 49 struct capture_control; 50 struct cfs_rq; 51 struct fs_struct; 52 struct futex_pi_state; 53 struct io_context; 54 struct io_uring_task; 55 struct mempolicy; 56 struct nameidata; 57 struct nsproxy; 58 struct perf_event_context; 59 struct pid_namespace; 60 struct pipe_inode_info; 61 struct rcu_node; 62 struct reclaim_state; 63 struct robust_list_head; 64 struct root_domain; 65 struct rq; 66 struct sched_attr; 67 struct sched_param; 68 struct seq_file; 69 struct sighand_struct; 70 struct signal_struct; 71 struct task_delay_info; 72 struct task_group; 73 struct user_event_mm; 74 75 /* 76 * Task state bitmask. NOTE! These bits are also 77 * encoded in fs/proc/array.c: get_task_state(). 78 * 79 * We have two separate sets of flags: task->state 80 * is about runnability, while task->exit_state are 81 * about the task exiting. Confusing, but this way 82 * modifying one set can't modify the other one by 83 * mistake. 84 */ 85 86 /* Used in tsk->state: */ 87 #define TASK_RUNNING 0x00000000 88 #define TASK_INTERRUPTIBLE 0x00000001 89 #define TASK_UNINTERRUPTIBLE 0x00000002 90 #define __TASK_STOPPED 0x00000004 91 #define __TASK_TRACED 0x00000008 92 /* Used in tsk->exit_state: */ 93 #define EXIT_DEAD 0x00000010 94 #define EXIT_ZOMBIE 0x00000020 95 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD) 96 /* Used in tsk->state again: */ 97 #define TASK_PARKED 0x00000040 98 #define TASK_DEAD 0x00000080 99 #define TASK_WAKEKILL 0x00000100 100 #define TASK_WAKING 0x00000200 101 #define TASK_NOLOAD 0x00000400 102 #define TASK_NEW 0x00000800 103 #define TASK_RTLOCK_WAIT 0x00001000 104 #define TASK_FREEZABLE 0x00002000 105 #define __TASK_FREEZABLE_UNSAFE (0x00004000 * IS_ENABLED(CONFIG_LOCKDEP)) 106 #define TASK_FROZEN 0x00008000 107 #define TASK_STATE_MAX 0x00010000 108 109 #define TASK_ANY (TASK_STATE_MAX-1) 110 111 /* 112 * DO NOT ADD ANY NEW USERS ! 113 */ 114 #define TASK_FREEZABLE_UNSAFE (TASK_FREEZABLE | __TASK_FREEZABLE_UNSAFE) 115 116 /* Convenience macros for the sake of set_current_state: */ 117 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE) 118 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED) 119 #define TASK_TRACED __TASK_TRACED 120 121 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD) 122 123 /* Convenience macros for the sake of wake_up(): */ 124 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE) 125 126 /* get_task_state(): */ 127 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \ 128 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \ 129 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \ 130 TASK_PARKED) 131 132 #define task_is_running(task) (READ_ONCE((task)->__state) == TASK_RUNNING) 133 134 #define task_is_traced(task) ((READ_ONCE(task->jobctl) & JOBCTL_TRACED) != 0) 135 #define task_is_stopped(task) ((READ_ONCE(task->jobctl) & JOBCTL_STOPPED) != 0) 136 #define task_is_stopped_or_traced(task) ((READ_ONCE(task->jobctl) & (JOBCTL_STOPPED | JOBCTL_TRACED)) != 0) 137 138 /* 139 * Special states are those that do not use the normal wait-loop pattern. See 140 * the comment with set_special_state(). 141 */ 142 #define is_special_task_state(state) \ 143 ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD)) 144 145 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 146 # define debug_normal_state_change(state_value) \ 147 do { \ 148 WARN_ON_ONCE(is_special_task_state(state_value)); \ 149 current->task_state_change = _THIS_IP_; \ 150 } while (0) 151 152 # define debug_special_state_change(state_value) \ 153 do { \ 154 WARN_ON_ONCE(!is_special_task_state(state_value)); \ 155 current->task_state_change = _THIS_IP_; \ 156 } while (0) 157 158 # define debug_rtlock_wait_set_state() \ 159 do { \ 160 current->saved_state_change = current->task_state_change;\ 161 current->task_state_change = _THIS_IP_; \ 162 } while (0) 163 164 # define debug_rtlock_wait_restore_state() \ 165 do { \ 166 current->task_state_change = current->saved_state_change;\ 167 } while (0) 168 169 #else 170 # define debug_normal_state_change(cond) do { } while (0) 171 # define debug_special_state_change(cond) do { } while (0) 172 # define debug_rtlock_wait_set_state() do { } while (0) 173 # define debug_rtlock_wait_restore_state() do { } while (0) 174 #endif 175 176 /* 177 * set_current_state() includes a barrier so that the write of current->state 178 * is correctly serialised wrt the caller's subsequent test of whether to 179 * actually sleep: 180 * 181 * for (;;) { 182 * set_current_state(TASK_UNINTERRUPTIBLE); 183 * if (CONDITION) 184 * break; 185 * 186 * schedule(); 187 * } 188 * __set_current_state(TASK_RUNNING); 189 * 190 * If the caller does not need such serialisation (because, for instance, the 191 * CONDITION test and condition change and wakeup are under the same lock) then 192 * use __set_current_state(). 193 * 194 * The above is typically ordered against the wakeup, which does: 195 * 196 * CONDITION = 1; 197 * wake_up_state(p, TASK_UNINTERRUPTIBLE); 198 * 199 * where wake_up_state()/try_to_wake_up() executes a full memory barrier before 200 * accessing p->state. 201 * 202 * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is, 203 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a 204 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING). 205 * 206 * However, with slightly different timing the wakeup TASK_RUNNING store can 207 * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not 208 * a problem either because that will result in one extra go around the loop 209 * and our @cond test will save the day. 210 * 211 * Also see the comments of try_to_wake_up(). 212 */ 213 #define __set_current_state(state_value) \ 214 do { \ 215 debug_normal_state_change((state_value)); \ 216 WRITE_ONCE(current->__state, (state_value)); \ 217 } while (0) 218 219 #define set_current_state(state_value) \ 220 do { \ 221 debug_normal_state_change((state_value)); \ 222 smp_store_mb(current->__state, (state_value)); \ 223 } while (0) 224 225 /* 226 * set_special_state() should be used for those states when the blocking task 227 * can not use the regular condition based wait-loop. In that case we must 228 * serialize against wakeups such that any possible in-flight TASK_RUNNING 229 * stores will not collide with our state change. 230 */ 231 #define set_special_state(state_value) \ 232 do { \ 233 unsigned long flags; /* may shadow */ \ 234 \ 235 raw_spin_lock_irqsave(¤t->pi_lock, flags); \ 236 debug_special_state_change((state_value)); \ 237 WRITE_ONCE(current->__state, (state_value)); \ 238 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \ 239 } while (0) 240 241 /* 242 * PREEMPT_RT specific variants for "sleeping" spin/rwlocks 243 * 244 * RT's spin/rwlock substitutions are state preserving. The state of the 245 * task when blocking on the lock is saved in task_struct::saved_state and 246 * restored after the lock has been acquired. These operations are 247 * serialized by task_struct::pi_lock against try_to_wake_up(). Any non RT 248 * lock related wakeups while the task is blocked on the lock are 249 * redirected to operate on task_struct::saved_state to ensure that these 250 * are not dropped. On restore task_struct::saved_state is set to 251 * TASK_RUNNING so any wakeup attempt redirected to saved_state will fail. 252 * 253 * The lock operation looks like this: 254 * 255 * current_save_and_set_rtlock_wait_state(); 256 * for (;;) { 257 * if (try_lock()) 258 * break; 259 * raw_spin_unlock_irq(&lock->wait_lock); 260 * schedule_rtlock(); 261 * raw_spin_lock_irq(&lock->wait_lock); 262 * set_current_state(TASK_RTLOCK_WAIT); 263 * } 264 * current_restore_rtlock_saved_state(); 265 */ 266 #define current_save_and_set_rtlock_wait_state() \ 267 do { \ 268 lockdep_assert_irqs_disabled(); \ 269 raw_spin_lock(¤t->pi_lock); \ 270 current->saved_state = current->__state; \ 271 debug_rtlock_wait_set_state(); \ 272 WRITE_ONCE(current->__state, TASK_RTLOCK_WAIT); \ 273 raw_spin_unlock(¤t->pi_lock); \ 274 } while (0); 275 276 #define current_restore_rtlock_saved_state() \ 277 do { \ 278 lockdep_assert_irqs_disabled(); \ 279 raw_spin_lock(¤t->pi_lock); \ 280 debug_rtlock_wait_restore_state(); \ 281 WRITE_ONCE(current->__state, current->saved_state); \ 282 current->saved_state = TASK_RUNNING; \ 283 raw_spin_unlock(¤t->pi_lock); \ 284 } while (0); 285 286 #define get_current_state() READ_ONCE(current->__state) 287 288 /* 289 * Define the task command name length as enum, then it can be visible to 290 * BPF programs. 291 */ 292 enum { 293 TASK_COMM_LEN = 16, 294 }; 295 296 extern void scheduler_tick(void); 297 298 #define MAX_SCHEDULE_TIMEOUT LONG_MAX 299 300 extern long schedule_timeout(long timeout); 301 extern long schedule_timeout_interruptible(long timeout); 302 extern long schedule_timeout_killable(long timeout); 303 extern long schedule_timeout_uninterruptible(long timeout); 304 extern long schedule_timeout_idle(long timeout); 305 asmlinkage void schedule(void); 306 extern void schedule_preempt_disabled(void); 307 asmlinkage void preempt_schedule_irq(void); 308 #ifdef CONFIG_PREEMPT_RT 309 extern void schedule_rtlock(void); 310 #endif 311 312 extern int __must_check io_schedule_prepare(void); 313 extern void io_schedule_finish(int token); 314 extern long io_schedule_timeout(long timeout); 315 extern void io_schedule(void); 316 317 /** 318 * struct prev_cputime - snapshot of system and user cputime 319 * @utime: time spent in user mode 320 * @stime: time spent in system mode 321 * @lock: protects the above two fields 322 * 323 * Stores previous user/system time values such that we can guarantee 324 * monotonicity. 325 */ 326 struct prev_cputime { 327 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE 328 u64 utime; 329 u64 stime; 330 raw_spinlock_t lock; 331 #endif 332 }; 333 334 enum vtime_state { 335 /* Task is sleeping or running in a CPU with VTIME inactive: */ 336 VTIME_INACTIVE = 0, 337 /* Task is idle */ 338 VTIME_IDLE, 339 /* Task runs in kernelspace in a CPU with VTIME active: */ 340 VTIME_SYS, 341 /* Task runs in userspace in a CPU with VTIME active: */ 342 VTIME_USER, 343 /* Task runs as guests in a CPU with VTIME active: */ 344 VTIME_GUEST, 345 }; 346 347 struct vtime { 348 seqcount_t seqcount; 349 unsigned long long starttime; 350 enum vtime_state state; 351 unsigned int cpu; 352 u64 utime; 353 u64 stime; 354 u64 gtime; 355 }; 356 357 /* 358 * Utilization clamp constraints. 359 * @UCLAMP_MIN: Minimum utilization 360 * @UCLAMP_MAX: Maximum utilization 361 * @UCLAMP_CNT: Utilization clamp constraints count 362 */ 363 enum uclamp_id { 364 UCLAMP_MIN = 0, 365 UCLAMP_MAX, 366 UCLAMP_CNT 367 }; 368 369 #ifdef CONFIG_SMP 370 extern struct root_domain def_root_domain; 371 extern struct mutex sched_domains_mutex; 372 #endif 373 374 struct sched_info { 375 #ifdef CONFIG_SCHED_INFO 376 /* Cumulative counters: */ 377 378 /* # of times we have run on this CPU: */ 379 unsigned long pcount; 380 381 /* Time spent waiting on a runqueue: */ 382 unsigned long long run_delay; 383 384 /* Timestamps: */ 385 386 /* When did we last run on a CPU? */ 387 unsigned long long last_arrival; 388 389 /* When were we last queued to run? */ 390 unsigned long long last_queued; 391 392 #endif /* CONFIG_SCHED_INFO */ 393 }; 394 395 /* 396 * Integer metrics need fixed point arithmetic, e.g., sched/fair 397 * has a few: load, load_avg, util_avg, freq, and capacity. 398 * 399 * We define a basic fixed point arithmetic range, and then formalize 400 * all these metrics based on that basic range. 401 */ 402 # define SCHED_FIXEDPOINT_SHIFT 10 403 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT) 404 405 /* Increase resolution of cpu_capacity calculations */ 406 # define SCHED_CAPACITY_SHIFT SCHED_FIXEDPOINT_SHIFT 407 # define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT) 408 409 struct load_weight { 410 unsigned long weight; 411 u32 inv_weight; 412 }; 413 414 /** 415 * struct util_est - Estimation utilization of FAIR tasks 416 * @enqueued: instantaneous estimated utilization of a task/cpu 417 * @ewma: the Exponential Weighted Moving Average (EWMA) 418 * utilization of a task 419 * 420 * Support data structure to track an Exponential Weighted Moving Average 421 * (EWMA) of a FAIR task's utilization. New samples are added to the moving 422 * average each time a task completes an activation. Sample's weight is chosen 423 * so that the EWMA will be relatively insensitive to transient changes to the 424 * task's workload. 425 * 426 * The enqueued attribute has a slightly different meaning for tasks and cpus: 427 * - task: the task's util_avg at last task dequeue time 428 * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU 429 * Thus, the util_est.enqueued of a task represents the contribution on the 430 * estimated utilization of the CPU where that task is currently enqueued. 431 * 432 * Only for tasks we track a moving average of the past instantaneous 433 * estimated utilization. This allows to absorb sporadic drops in utilization 434 * of an otherwise almost periodic task. 435 * 436 * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg 437 * updates. When a task is dequeued, its util_est should not be updated if its 438 * util_avg has not been updated in the meantime. 439 * This information is mapped into the MSB bit of util_est.enqueued at dequeue 440 * time. Since max value of util_est.enqueued for a task is 1024 (PELT util_avg 441 * for a task) it is safe to use MSB. 442 */ 443 struct util_est { 444 unsigned int enqueued; 445 unsigned int ewma; 446 #define UTIL_EST_WEIGHT_SHIFT 2 447 #define UTIL_AVG_UNCHANGED 0x80000000 448 } __attribute__((__aligned__(sizeof(u64)))); 449 450 /* 451 * The load/runnable/util_avg accumulates an infinite geometric series 452 * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c). 453 * 454 * [load_avg definition] 455 * 456 * load_avg = runnable% * scale_load_down(load) 457 * 458 * [runnable_avg definition] 459 * 460 * runnable_avg = runnable% * SCHED_CAPACITY_SCALE 461 * 462 * [util_avg definition] 463 * 464 * util_avg = running% * SCHED_CAPACITY_SCALE 465 * 466 * where runnable% is the time ratio that a sched_entity is runnable and 467 * running% the time ratio that a sched_entity is running. 468 * 469 * For cfs_rq, they are the aggregated values of all runnable and blocked 470 * sched_entities. 471 * 472 * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU 473 * capacity scaling. The scaling is done through the rq_clock_pelt that is used 474 * for computing those signals (see update_rq_clock_pelt()) 475 * 476 * N.B., the above ratios (runnable% and running%) themselves are in the 477 * range of [0, 1]. To do fixed point arithmetics, we therefore scale them 478 * to as large a range as necessary. This is for example reflected by 479 * util_avg's SCHED_CAPACITY_SCALE. 480 * 481 * [Overflow issue] 482 * 483 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities 484 * with the highest load (=88761), always runnable on a single cfs_rq, 485 * and should not overflow as the number already hits PID_MAX_LIMIT. 486 * 487 * For all other cases (including 32-bit kernels), struct load_weight's 488 * weight will overflow first before we do, because: 489 * 490 * Max(load_avg) <= Max(load.weight) 491 * 492 * Then it is the load_weight's responsibility to consider overflow 493 * issues. 494 */ 495 struct sched_avg { 496 u64 last_update_time; 497 u64 load_sum; 498 u64 runnable_sum; 499 u32 util_sum; 500 u32 period_contrib; 501 unsigned long load_avg; 502 unsigned long runnable_avg; 503 unsigned long util_avg; 504 struct util_est util_est; 505 } ____cacheline_aligned; 506 507 struct sched_statistics { 508 #ifdef CONFIG_SCHEDSTATS 509 u64 wait_start; 510 u64 wait_max; 511 u64 wait_count; 512 u64 wait_sum; 513 u64 iowait_count; 514 u64 iowait_sum; 515 516 u64 sleep_start; 517 u64 sleep_max; 518 s64 sum_sleep_runtime; 519 520 u64 block_start; 521 u64 block_max; 522 s64 sum_block_runtime; 523 524 u64 exec_max; 525 u64 slice_max; 526 527 u64 nr_migrations_cold; 528 u64 nr_failed_migrations_affine; 529 u64 nr_failed_migrations_running; 530 u64 nr_failed_migrations_hot; 531 u64 nr_forced_migrations; 532 533 u64 nr_wakeups; 534 u64 nr_wakeups_sync; 535 u64 nr_wakeups_migrate; 536 u64 nr_wakeups_local; 537 u64 nr_wakeups_remote; 538 u64 nr_wakeups_affine; 539 u64 nr_wakeups_affine_attempts; 540 u64 nr_wakeups_passive; 541 u64 nr_wakeups_idle; 542 543 #ifdef CONFIG_SCHED_CORE 544 u64 core_forceidle_sum; 545 #endif 546 #endif /* CONFIG_SCHEDSTATS */ 547 } ____cacheline_aligned; 548 549 struct sched_entity { 550 /* For load-balancing: */ 551 struct load_weight load; 552 struct rb_node run_node; 553 struct list_head group_node; 554 unsigned int on_rq; 555 556 u64 exec_start; 557 u64 sum_exec_runtime; 558 u64 vruntime; 559 u64 prev_sum_exec_runtime; 560 561 u64 nr_migrations; 562 563 #ifdef CONFIG_FAIR_GROUP_SCHED 564 int depth; 565 struct sched_entity *parent; 566 /* rq on which this entity is (to be) queued: */ 567 struct cfs_rq *cfs_rq; 568 /* rq "owned" by this entity/group: */ 569 struct cfs_rq *my_q; 570 /* cached value of my_q->h_nr_running */ 571 unsigned long runnable_weight; 572 #endif 573 574 #ifdef CONFIG_SMP 575 /* 576 * Per entity load average tracking. 577 * 578 * Put into separate cache line so it does not 579 * collide with read-mostly values above. 580 */ 581 struct sched_avg avg; 582 #endif 583 }; 584 585 struct sched_rt_entity { 586 struct list_head run_list; 587 unsigned long timeout; 588 unsigned long watchdog_stamp; 589 unsigned int time_slice; 590 unsigned short on_rq; 591 unsigned short on_list; 592 593 struct sched_rt_entity *back; 594 #ifdef CONFIG_RT_GROUP_SCHED 595 struct sched_rt_entity *parent; 596 /* rq on which this entity is (to be) queued: */ 597 struct rt_rq *rt_rq; 598 /* rq "owned" by this entity/group: */ 599 struct rt_rq *my_q; 600 #endif 601 } __randomize_layout; 602 603 struct sched_dl_entity { 604 struct rb_node rb_node; 605 606 /* 607 * Original scheduling parameters. Copied here from sched_attr 608 * during sched_setattr(), they will remain the same until 609 * the next sched_setattr(). 610 */ 611 u64 dl_runtime; /* Maximum runtime for each instance */ 612 u64 dl_deadline; /* Relative deadline of each instance */ 613 u64 dl_period; /* Separation of two instances (period) */ 614 u64 dl_bw; /* dl_runtime / dl_period */ 615 u64 dl_density; /* dl_runtime / dl_deadline */ 616 617 /* 618 * Actual scheduling parameters. Initialized with the values above, 619 * they are continuously updated during task execution. Note that 620 * the remaining runtime could be < 0 in case we are in overrun. 621 */ 622 s64 runtime; /* Remaining runtime for this instance */ 623 u64 deadline; /* Absolute deadline for this instance */ 624 unsigned int flags; /* Specifying the scheduler behaviour */ 625 626 /* 627 * Some bool flags: 628 * 629 * @dl_throttled tells if we exhausted the runtime. If so, the 630 * task has to wait for a replenishment to be performed at the 631 * next firing of dl_timer. 632 * 633 * @dl_yielded tells if task gave up the CPU before consuming 634 * all its available runtime during the last job. 635 * 636 * @dl_non_contending tells if the task is inactive while still 637 * contributing to the active utilization. In other words, it 638 * indicates if the inactive timer has been armed and its handler 639 * has not been executed yet. This flag is useful to avoid race 640 * conditions between the inactive timer handler and the wakeup 641 * code. 642 * 643 * @dl_overrun tells if the task asked to be informed about runtime 644 * overruns. 645 */ 646 unsigned int dl_throttled : 1; 647 unsigned int dl_yielded : 1; 648 unsigned int dl_non_contending : 1; 649 unsigned int dl_overrun : 1; 650 651 /* 652 * Bandwidth enforcement timer. Each -deadline task has its 653 * own bandwidth to be enforced, thus we need one timer per task. 654 */ 655 struct hrtimer dl_timer; 656 657 /* 658 * Inactive timer, responsible for decreasing the active utilization 659 * at the "0-lag time". When a -deadline task blocks, it contributes 660 * to GRUB's active utilization until the "0-lag time", hence a 661 * timer is needed to decrease the active utilization at the correct 662 * time. 663 */ 664 struct hrtimer inactive_timer; 665 666 #ifdef CONFIG_RT_MUTEXES 667 /* 668 * Priority Inheritance. When a DEADLINE scheduling entity is boosted 669 * pi_se points to the donor, otherwise points to the dl_se it belongs 670 * to (the original one/itself). 671 */ 672 struct sched_dl_entity *pi_se; 673 #endif 674 }; 675 676 #ifdef CONFIG_UCLAMP_TASK 677 /* Number of utilization clamp buckets (shorter alias) */ 678 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT 679 680 /* 681 * Utilization clamp for a scheduling entity 682 * @value: clamp value "assigned" to a se 683 * @bucket_id: bucket index corresponding to the "assigned" value 684 * @active: the se is currently refcounted in a rq's bucket 685 * @user_defined: the requested clamp value comes from user-space 686 * 687 * The bucket_id is the index of the clamp bucket matching the clamp value 688 * which is pre-computed and stored to avoid expensive integer divisions from 689 * the fast path. 690 * 691 * The active bit is set whenever a task has got an "effective" value assigned, 692 * which can be different from the clamp value "requested" from user-space. 693 * This allows to know a task is refcounted in the rq's bucket corresponding 694 * to the "effective" bucket_id. 695 * 696 * The user_defined bit is set whenever a task has got a task-specific clamp 697 * value requested from userspace, i.e. the system defaults apply to this task 698 * just as a restriction. This allows to relax default clamps when a less 699 * restrictive task-specific value has been requested, thus allowing to 700 * implement a "nice" semantic. For example, a task running with a 20% 701 * default boost can still drop its own boosting to 0%. 702 */ 703 struct uclamp_se { 704 unsigned int value : bits_per(SCHED_CAPACITY_SCALE); 705 unsigned int bucket_id : bits_per(UCLAMP_BUCKETS); 706 unsigned int active : 1; 707 unsigned int user_defined : 1; 708 }; 709 #endif /* CONFIG_UCLAMP_TASK */ 710 711 union rcu_special { 712 struct { 713 u8 blocked; 714 u8 need_qs; 715 u8 exp_hint; /* Hint for performance. */ 716 u8 need_mb; /* Readers need smp_mb(). */ 717 } b; /* Bits. */ 718 u32 s; /* Set of bits. */ 719 }; 720 721 enum perf_event_task_context { 722 perf_invalid_context = -1, 723 perf_hw_context = 0, 724 perf_sw_context, 725 perf_nr_task_contexts, 726 }; 727 728 struct wake_q_node { 729 struct wake_q_node *next; 730 }; 731 732 struct kmap_ctrl { 733 #ifdef CONFIG_KMAP_LOCAL 734 int idx; 735 pte_t pteval[KM_MAX_IDX]; 736 #endif 737 }; 738 739 struct task_struct { 740 #ifdef CONFIG_THREAD_INFO_IN_TASK 741 /* 742 * For reasons of header soup (see current_thread_info()), this 743 * must be the first element of task_struct. 744 */ 745 struct thread_info thread_info; 746 #endif 747 unsigned int __state; 748 749 #ifdef CONFIG_PREEMPT_RT 750 /* saved state for "spinlock sleepers" */ 751 unsigned int saved_state; 752 #endif 753 754 /* 755 * This begins the randomizable portion of task_struct. Only 756 * scheduling-critical items should be added above here. 757 */ 758 randomized_struct_fields_start 759 760 void *stack; 761 refcount_t usage; 762 /* Per task flags (PF_*), defined further below: */ 763 unsigned int flags; 764 unsigned int ptrace; 765 766 #ifdef CONFIG_SMP 767 int on_cpu; 768 struct __call_single_node wake_entry; 769 unsigned int wakee_flips; 770 unsigned long wakee_flip_decay_ts; 771 struct task_struct *last_wakee; 772 773 /* 774 * recent_used_cpu is initially set as the last CPU used by a task 775 * that wakes affine another task. Waker/wakee relationships can 776 * push tasks around a CPU where each wakeup moves to the next one. 777 * Tracking a recently used CPU allows a quick search for a recently 778 * used CPU that may be idle. 779 */ 780 int recent_used_cpu; 781 int wake_cpu; 782 #endif 783 int on_rq; 784 785 int prio; 786 int static_prio; 787 int normal_prio; 788 unsigned int rt_priority; 789 790 struct sched_entity se; 791 struct sched_rt_entity rt; 792 struct sched_dl_entity dl; 793 const struct sched_class *sched_class; 794 795 #ifdef CONFIG_SCHED_CORE 796 struct rb_node core_node; 797 unsigned long core_cookie; 798 unsigned int core_occupation; 799 #endif 800 801 #ifdef CONFIG_CGROUP_SCHED 802 struct task_group *sched_task_group; 803 #endif 804 805 #ifdef CONFIG_UCLAMP_TASK 806 /* 807 * Clamp values requested for a scheduling entity. 808 * Must be updated with task_rq_lock() held. 809 */ 810 struct uclamp_se uclamp_req[UCLAMP_CNT]; 811 /* 812 * Effective clamp values used for a scheduling entity. 813 * Must be updated with task_rq_lock() held. 814 */ 815 struct uclamp_se uclamp[UCLAMP_CNT]; 816 #endif 817 818 struct sched_statistics stats; 819 820 #ifdef CONFIG_PREEMPT_NOTIFIERS 821 /* List of struct preempt_notifier: */ 822 struct hlist_head preempt_notifiers; 823 #endif 824 825 #ifdef CONFIG_BLK_DEV_IO_TRACE 826 unsigned int btrace_seq; 827 #endif 828 829 unsigned int policy; 830 int nr_cpus_allowed; 831 const cpumask_t *cpus_ptr; 832 cpumask_t *user_cpus_ptr; 833 cpumask_t cpus_mask; 834 void *migration_pending; 835 #ifdef CONFIG_SMP 836 unsigned short migration_disabled; 837 #endif 838 unsigned short migration_flags; 839 840 #ifdef CONFIG_PREEMPT_RCU 841 int rcu_read_lock_nesting; 842 union rcu_special rcu_read_unlock_special; 843 struct list_head rcu_node_entry; 844 struct rcu_node *rcu_blocked_node; 845 #endif /* #ifdef CONFIG_PREEMPT_RCU */ 846 847 #ifdef CONFIG_TASKS_RCU 848 unsigned long rcu_tasks_nvcsw; 849 u8 rcu_tasks_holdout; 850 u8 rcu_tasks_idx; 851 int rcu_tasks_idle_cpu; 852 struct list_head rcu_tasks_holdout_list; 853 #endif /* #ifdef CONFIG_TASKS_RCU */ 854 855 #ifdef CONFIG_TASKS_TRACE_RCU 856 int trc_reader_nesting; 857 int trc_ipi_to_cpu; 858 union rcu_special trc_reader_special; 859 struct list_head trc_holdout_list; 860 struct list_head trc_blkd_node; 861 int trc_blkd_cpu; 862 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */ 863 864 struct sched_info sched_info; 865 866 struct list_head tasks; 867 #ifdef CONFIG_SMP 868 struct plist_node pushable_tasks; 869 struct rb_node pushable_dl_tasks; 870 #endif 871 872 struct mm_struct *mm; 873 struct mm_struct *active_mm; 874 875 int exit_state; 876 int exit_code; 877 int exit_signal; 878 /* The signal sent when the parent dies: */ 879 int pdeath_signal; 880 /* JOBCTL_*, siglock protected: */ 881 unsigned long jobctl; 882 883 /* Used for emulating ABI behavior of previous Linux versions: */ 884 unsigned int personality; 885 886 /* Scheduler bits, serialized by scheduler locks: */ 887 unsigned sched_reset_on_fork:1; 888 unsigned sched_contributes_to_load:1; 889 unsigned sched_migrated:1; 890 891 /* Force alignment to the next boundary: */ 892 unsigned :0; 893 894 /* Unserialized, strictly 'current' */ 895 896 /* 897 * This field must not be in the scheduler word above due to wakelist 898 * queueing no longer being serialized by p->on_cpu. However: 899 * 900 * p->XXX = X; ttwu() 901 * schedule() if (p->on_rq && ..) // false 902 * smp_mb__after_spinlock(); if (smp_load_acquire(&p->on_cpu) && //true 903 * deactivate_task() ttwu_queue_wakelist()) 904 * p->on_rq = 0; p->sched_remote_wakeup = Y; 905 * 906 * guarantees all stores of 'current' are visible before 907 * ->sched_remote_wakeup gets used, so it can be in this word. 908 */ 909 unsigned sched_remote_wakeup:1; 910 911 /* Bit to tell LSMs we're in execve(): */ 912 unsigned in_execve:1; 913 unsigned in_iowait:1; 914 #ifndef TIF_RESTORE_SIGMASK 915 unsigned restore_sigmask:1; 916 #endif 917 #ifdef CONFIG_MEMCG 918 unsigned in_user_fault:1; 919 #endif 920 #ifdef CONFIG_LRU_GEN 921 /* whether the LRU algorithm may apply to this access */ 922 unsigned in_lru_fault:1; 923 #endif 924 #ifdef CONFIG_COMPAT_BRK 925 unsigned brk_randomized:1; 926 #endif 927 #ifdef CONFIG_CGROUPS 928 /* disallow userland-initiated cgroup migration */ 929 unsigned no_cgroup_migration:1; 930 /* task is frozen/stopped (used by the cgroup freezer) */ 931 unsigned frozen:1; 932 #endif 933 #ifdef CONFIG_BLK_CGROUP 934 unsigned use_memdelay:1; 935 #endif 936 #ifdef CONFIG_PSI 937 /* Stalled due to lack of memory */ 938 unsigned in_memstall:1; 939 #endif 940 #ifdef CONFIG_PAGE_OWNER 941 /* Used by page_owner=on to detect recursion in page tracking. */ 942 unsigned in_page_owner:1; 943 #endif 944 #ifdef CONFIG_EVENTFD 945 /* Recursion prevention for eventfd_signal() */ 946 unsigned in_eventfd:1; 947 #endif 948 #ifdef CONFIG_IOMMU_SVA 949 unsigned pasid_activated:1; 950 #endif 951 #ifdef CONFIG_CPU_SUP_INTEL 952 unsigned reported_split_lock:1; 953 #endif 954 #ifdef CONFIG_TASK_DELAY_ACCT 955 /* delay due to memory thrashing */ 956 unsigned in_thrashing:1; 957 #endif 958 959 unsigned long atomic_flags; /* Flags requiring atomic access. */ 960 961 struct restart_block restart_block; 962 963 pid_t pid; 964 pid_t tgid; 965 966 #ifdef CONFIG_STACKPROTECTOR 967 /* Canary value for the -fstack-protector GCC feature: */ 968 unsigned long stack_canary; 969 #endif 970 /* 971 * Pointers to the (original) parent process, youngest child, younger sibling, 972 * older sibling, respectively. (p->father can be replaced with 973 * p->real_parent->pid) 974 */ 975 976 /* Real parent process: */ 977 struct task_struct __rcu *real_parent; 978 979 /* Recipient of SIGCHLD, wait4() reports: */ 980 struct task_struct __rcu *parent; 981 982 /* 983 * Children/sibling form the list of natural children: 984 */ 985 struct list_head children; 986 struct list_head sibling; 987 struct task_struct *group_leader; 988 989 /* 990 * 'ptraced' is the list of tasks this task is using ptrace() on. 991 * 992 * This includes both natural children and PTRACE_ATTACH targets. 993 * 'ptrace_entry' is this task's link on the p->parent->ptraced list. 994 */ 995 struct list_head ptraced; 996 struct list_head ptrace_entry; 997 998 /* PID/PID hash table linkage. */ 999 struct pid *thread_pid; 1000 struct hlist_node pid_links[PIDTYPE_MAX]; 1001 struct list_head thread_group; 1002 struct list_head thread_node; 1003 1004 struct completion *vfork_done; 1005 1006 /* CLONE_CHILD_SETTID: */ 1007 int __user *set_child_tid; 1008 1009 /* CLONE_CHILD_CLEARTID: */ 1010 int __user *clear_child_tid; 1011 1012 /* PF_KTHREAD | PF_IO_WORKER */ 1013 void *worker_private; 1014 1015 u64 utime; 1016 u64 stime; 1017 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME 1018 u64 utimescaled; 1019 u64 stimescaled; 1020 #endif 1021 u64 gtime; 1022 struct prev_cputime prev_cputime; 1023 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN 1024 struct vtime vtime; 1025 #endif 1026 1027 #ifdef CONFIG_NO_HZ_FULL 1028 atomic_t tick_dep_mask; 1029 #endif 1030 /* Context switch counts: */ 1031 unsigned long nvcsw; 1032 unsigned long nivcsw; 1033 1034 /* Monotonic time in nsecs: */ 1035 u64 start_time; 1036 1037 /* Boot based time in nsecs: */ 1038 u64 start_boottime; 1039 1040 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */ 1041 unsigned long min_flt; 1042 unsigned long maj_flt; 1043 1044 /* Empty if CONFIG_POSIX_CPUTIMERS=n */ 1045 struct posix_cputimers posix_cputimers; 1046 1047 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK 1048 struct posix_cputimers_work posix_cputimers_work; 1049 #endif 1050 1051 /* Process credentials: */ 1052 1053 /* Tracer's credentials at attach: */ 1054 const struct cred __rcu *ptracer_cred; 1055 1056 /* Objective and real subjective task credentials (COW): */ 1057 const struct cred __rcu *real_cred; 1058 1059 /* Effective (overridable) subjective task credentials (COW): */ 1060 const struct cred __rcu *cred; 1061 1062 #ifdef CONFIG_KEYS 1063 /* Cached requested key. */ 1064 struct key *cached_requested_key; 1065 #endif 1066 1067 /* 1068 * executable name, excluding path. 1069 * 1070 * - normally initialized setup_new_exec() 1071 * - access it with [gs]et_task_comm() 1072 * - lock it with task_lock() 1073 */ 1074 char comm[TASK_COMM_LEN]; 1075 1076 struct nameidata *nameidata; 1077 1078 #ifdef CONFIG_SYSVIPC 1079 struct sysv_sem sysvsem; 1080 struct sysv_shm sysvshm; 1081 #endif 1082 #ifdef CONFIG_DETECT_HUNG_TASK 1083 unsigned long last_switch_count; 1084 unsigned long last_switch_time; 1085 #endif 1086 /* Filesystem information: */ 1087 struct fs_struct *fs; 1088 1089 /* Open file information: */ 1090 struct files_struct *files; 1091 1092 #ifdef CONFIG_IO_URING 1093 struct io_uring_task *io_uring; 1094 #endif 1095 1096 /* Namespaces: */ 1097 struct nsproxy *nsproxy; 1098 1099 /* Signal handlers: */ 1100 struct signal_struct *signal; 1101 struct sighand_struct __rcu *sighand; 1102 sigset_t blocked; 1103 sigset_t real_blocked; 1104 /* Restored if set_restore_sigmask() was used: */ 1105 sigset_t saved_sigmask; 1106 struct sigpending pending; 1107 unsigned long sas_ss_sp; 1108 size_t sas_ss_size; 1109 unsigned int sas_ss_flags; 1110 1111 struct callback_head *task_works; 1112 1113 #ifdef CONFIG_AUDIT 1114 #ifdef CONFIG_AUDITSYSCALL 1115 struct audit_context *audit_context; 1116 #endif 1117 kuid_t loginuid; 1118 unsigned int sessionid; 1119 #endif 1120 struct seccomp seccomp; 1121 struct syscall_user_dispatch syscall_dispatch; 1122 1123 /* Thread group tracking: */ 1124 u64 parent_exec_id; 1125 u64 self_exec_id; 1126 1127 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */ 1128 spinlock_t alloc_lock; 1129 1130 /* Protection of the PI data structures: */ 1131 raw_spinlock_t pi_lock; 1132 1133 struct wake_q_node wake_q; 1134 1135 #ifdef CONFIG_RT_MUTEXES 1136 /* PI waiters blocked on a rt_mutex held by this task: */ 1137 struct rb_root_cached pi_waiters; 1138 /* Updated under owner's pi_lock and rq lock */ 1139 struct task_struct *pi_top_task; 1140 /* Deadlock detection and priority inheritance handling: */ 1141 struct rt_mutex_waiter *pi_blocked_on; 1142 #endif 1143 1144 #ifdef CONFIG_DEBUG_MUTEXES 1145 /* Mutex deadlock detection: */ 1146 struct mutex_waiter *blocked_on; 1147 #endif 1148 1149 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1150 int non_block_count; 1151 #endif 1152 1153 #ifdef CONFIG_TRACE_IRQFLAGS 1154 struct irqtrace_events irqtrace; 1155 unsigned int hardirq_threaded; 1156 u64 hardirq_chain_key; 1157 int softirqs_enabled; 1158 int softirq_context; 1159 int irq_config; 1160 #endif 1161 #ifdef CONFIG_PREEMPT_RT 1162 int softirq_disable_cnt; 1163 #endif 1164 1165 #ifdef CONFIG_LOCKDEP 1166 # define MAX_LOCK_DEPTH 48UL 1167 u64 curr_chain_key; 1168 int lockdep_depth; 1169 unsigned int lockdep_recursion; 1170 struct held_lock held_locks[MAX_LOCK_DEPTH]; 1171 #endif 1172 1173 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP) 1174 unsigned int in_ubsan; 1175 #endif 1176 1177 /* Journalling filesystem info: */ 1178 void *journal_info; 1179 1180 /* Stacked block device info: */ 1181 struct bio_list *bio_list; 1182 1183 /* Stack plugging: */ 1184 struct blk_plug *plug; 1185 1186 /* VM state: */ 1187 struct reclaim_state *reclaim_state; 1188 1189 struct backing_dev_info *backing_dev_info; 1190 1191 struct io_context *io_context; 1192 1193 #ifdef CONFIG_COMPACTION 1194 struct capture_control *capture_control; 1195 #endif 1196 /* Ptrace state: */ 1197 unsigned long ptrace_message; 1198 kernel_siginfo_t *last_siginfo; 1199 1200 struct task_io_accounting ioac; 1201 #ifdef CONFIG_PSI 1202 /* Pressure stall state */ 1203 unsigned int psi_flags; 1204 #endif 1205 #ifdef CONFIG_TASK_XACCT 1206 /* Accumulated RSS usage: */ 1207 u64 acct_rss_mem1; 1208 /* Accumulated virtual memory usage: */ 1209 u64 acct_vm_mem1; 1210 /* stime + utime since last update: */ 1211 u64 acct_timexpd; 1212 #endif 1213 #ifdef CONFIG_CPUSETS 1214 /* Protected by ->alloc_lock: */ 1215 nodemask_t mems_allowed; 1216 /* Sequence number to catch updates: */ 1217 seqcount_spinlock_t mems_allowed_seq; 1218 int cpuset_mem_spread_rotor; 1219 int cpuset_slab_spread_rotor; 1220 #endif 1221 #ifdef CONFIG_CGROUPS 1222 /* Control Group info protected by css_set_lock: */ 1223 struct css_set __rcu *cgroups; 1224 /* cg_list protected by css_set_lock and tsk->alloc_lock: */ 1225 struct list_head cg_list; 1226 #endif 1227 #ifdef CONFIG_X86_CPU_RESCTRL 1228 u32 closid; 1229 u32 rmid; 1230 #endif 1231 #ifdef CONFIG_FUTEX 1232 struct robust_list_head __user *robust_list; 1233 #ifdef CONFIG_COMPAT 1234 struct compat_robust_list_head __user *compat_robust_list; 1235 #endif 1236 struct list_head pi_state_list; 1237 struct futex_pi_state *pi_state_cache; 1238 struct mutex futex_exit_mutex; 1239 unsigned int futex_state; 1240 #endif 1241 #ifdef CONFIG_PERF_EVENTS 1242 struct perf_event_context *perf_event_ctxp; 1243 struct mutex perf_event_mutex; 1244 struct list_head perf_event_list; 1245 #endif 1246 #ifdef CONFIG_DEBUG_PREEMPT 1247 unsigned long preempt_disable_ip; 1248 #endif 1249 #ifdef CONFIG_NUMA 1250 /* Protected by alloc_lock: */ 1251 struct mempolicy *mempolicy; 1252 short il_prev; 1253 short pref_node_fork; 1254 #endif 1255 #ifdef CONFIG_NUMA_BALANCING 1256 int numa_scan_seq; 1257 unsigned int numa_scan_period; 1258 unsigned int numa_scan_period_max; 1259 int numa_preferred_nid; 1260 unsigned long numa_migrate_retry; 1261 /* Migration stamp: */ 1262 u64 node_stamp; 1263 u64 last_task_numa_placement; 1264 u64 last_sum_exec_runtime; 1265 struct callback_head numa_work; 1266 1267 /* 1268 * This pointer is only modified for current in syscall and 1269 * pagefault context (and for tasks being destroyed), so it can be read 1270 * from any of the following contexts: 1271 * - RCU read-side critical section 1272 * - current->numa_group from everywhere 1273 * - task's runqueue locked, task not running 1274 */ 1275 struct numa_group __rcu *numa_group; 1276 1277 /* 1278 * numa_faults is an array split into four regions: 1279 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer 1280 * in this precise order. 1281 * 1282 * faults_memory: Exponential decaying average of faults on a per-node 1283 * basis. Scheduling placement decisions are made based on these 1284 * counts. The values remain static for the duration of a PTE scan. 1285 * faults_cpu: Track the nodes the process was running on when a NUMA 1286 * hinting fault was incurred. 1287 * faults_memory_buffer and faults_cpu_buffer: Record faults per node 1288 * during the current scan window. When the scan completes, the counts 1289 * in faults_memory and faults_cpu decay and these values are copied. 1290 */ 1291 unsigned long *numa_faults; 1292 unsigned long total_numa_faults; 1293 1294 /* 1295 * numa_faults_locality tracks if faults recorded during the last 1296 * scan window were remote/local or failed to migrate. The task scan 1297 * period is adapted based on the locality of the faults with different 1298 * weights depending on whether they were shared or private faults 1299 */ 1300 unsigned long numa_faults_locality[3]; 1301 1302 unsigned long numa_pages_migrated; 1303 #endif /* CONFIG_NUMA_BALANCING */ 1304 1305 #ifdef CONFIG_RSEQ 1306 struct rseq __user *rseq; 1307 u32 rseq_len; 1308 u32 rseq_sig; 1309 /* 1310 * RmW on rseq_event_mask must be performed atomically 1311 * with respect to preemption. 1312 */ 1313 unsigned long rseq_event_mask; 1314 #endif 1315 1316 #ifdef CONFIG_SCHED_MM_CID 1317 int mm_cid; /* Current cid in mm */ 1318 int last_mm_cid; /* Most recent cid in mm */ 1319 int migrate_from_cpu; 1320 int mm_cid_active; /* Whether cid bitmap is active */ 1321 struct callback_head cid_work; 1322 #endif 1323 1324 struct tlbflush_unmap_batch tlb_ubc; 1325 1326 /* Cache last used pipe for splice(): */ 1327 struct pipe_inode_info *splice_pipe; 1328 1329 struct page_frag task_frag; 1330 1331 #ifdef CONFIG_TASK_DELAY_ACCT 1332 struct task_delay_info *delays; 1333 #endif 1334 1335 #ifdef CONFIG_FAULT_INJECTION 1336 int make_it_fail; 1337 unsigned int fail_nth; 1338 #endif 1339 /* 1340 * When (nr_dirtied >= nr_dirtied_pause), it's time to call 1341 * balance_dirty_pages() for a dirty throttling pause: 1342 */ 1343 int nr_dirtied; 1344 int nr_dirtied_pause; 1345 /* Start of a write-and-pause period: */ 1346 unsigned long dirty_paused_when; 1347 1348 #ifdef CONFIG_LATENCYTOP 1349 int latency_record_count; 1350 struct latency_record latency_record[LT_SAVECOUNT]; 1351 #endif 1352 /* 1353 * Time slack values; these are used to round up poll() and 1354 * select() etc timeout values. These are in nanoseconds. 1355 */ 1356 u64 timer_slack_ns; 1357 u64 default_timer_slack_ns; 1358 1359 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) 1360 unsigned int kasan_depth; 1361 #endif 1362 1363 #ifdef CONFIG_KCSAN 1364 struct kcsan_ctx kcsan_ctx; 1365 #ifdef CONFIG_TRACE_IRQFLAGS 1366 struct irqtrace_events kcsan_save_irqtrace; 1367 #endif 1368 #ifdef CONFIG_KCSAN_WEAK_MEMORY 1369 int kcsan_stack_depth; 1370 #endif 1371 #endif 1372 1373 #ifdef CONFIG_KMSAN 1374 struct kmsan_ctx kmsan_ctx; 1375 #endif 1376 1377 #if IS_ENABLED(CONFIG_KUNIT) 1378 struct kunit *kunit_test; 1379 #endif 1380 1381 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 1382 /* Index of current stored address in ret_stack: */ 1383 int curr_ret_stack; 1384 int curr_ret_depth; 1385 1386 /* Stack of return addresses for return function tracing: */ 1387 struct ftrace_ret_stack *ret_stack; 1388 1389 /* Timestamp for last schedule: */ 1390 unsigned long long ftrace_timestamp; 1391 1392 /* 1393 * Number of functions that haven't been traced 1394 * because of depth overrun: 1395 */ 1396 atomic_t trace_overrun; 1397 1398 /* Pause tracing: */ 1399 atomic_t tracing_graph_pause; 1400 #endif 1401 1402 #ifdef CONFIG_TRACING 1403 /* Bitmask and counter of trace recursion: */ 1404 unsigned long trace_recursion; 1405 #endif /* CONFIG_TRACING */ 1406 1407 #ifdef CONFIG_KCOV 1408 /* See kernel/kcov.c for more details. */ 1409 1410 /* Coverage collection mode enabled for this task (0 if disabled): */ 1411 unsigned int kcov_mode; 1412 1413 /* Size of the kcov_area: */ 1414 unsigned int kcov_size; 1415 1416 /* Buffer for coverage collection: */ 1417 void *kcov_area; 1418 1419 /* KCOV descriptor wired with this task or NULL: */ 1420 struct kcov *kcov; 1421 1422 /* KCOV common handle for remote coverage collection: */ 1423 u64 kcov_handle; 1424 1425 /* KCOV sequence number: */ 1426 int kcov_sequence; 1427 1428 /* Collect coverage from softirq context: */ 1429 unsigned int kcov_softirq; 1430 #endif 1431 1432 #ifdef CONFIG_MEMCG 1433 struct mem_cgroup *memcg_in_oom; 1434 gfp_t memcg_oom_gfp_mask; 1435 int memcg_oom_order; 1436 1437 /* Number of pages to reclaim on returning to userland: */ 1438 unsigned int memcg_nr_pages_over_high; 1439 1440 /* Used by memcontrol for targeted memcg charge: */ 1441 struct mem_cgroup *active_memcg; 1442 #endif 1443 1444 #ifdef CONFIG_BLK_CGROUP 1445 struct gendisk *throttle_disk; 1446 #endif 1447 1448 #ifdef CONFIG_UPROBES 1449 struct uprobe_task *utask; 1450 #endif 1451 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE) 1452 unsigned int sequential_io; 1453 unsigned int sequential_io_avg; 1454 #endif 1455 struct kmap_ctrl kmap_ctrl; 1456 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1457 unsigned long task_state_change; 1458 # ifdef CONFIG_PREEMPT_RT 1459 unsigned long saved_state_change; 1460 # endif 1461 #endif 1462 struct rcu_head rcu; 1463 refcount_t rcu_users; 1464 int pagefault_disabled; 1465 #ifdef CONFIG_MMU 1466 struct task_struct *oom_reaper_list; 1467 struct timer_list oom_reaper_timer; 1468 #endif 1469 #ifdef CONFIG_VMAP_STACK 1470 struct vm_struct *stack_vm_area; 1471 #endif 1472 #ifdef CONFIG_THREAD_INFO_IN_TASK 1473 /* A live task holds one reference: */ 1474 refcount_t stack_refcount; 1475 #endif 1476 #ifdef CONFIG_LIVEPATCH 1477 int patch_state; 1478 #endif 1479 #ifdef CONFIG_SECURITY 1480 /* Used by LSM modules for access restriction: */ 1481 void *security; 1482 #endif 1483 #ifdef CONFIG_BPF_SYSCALL 1484 /* Used by BPF task local storage */ 1485 struct bpf_local_storage __rcu *bpf_storage; 1486 /* Used for BPF run context */ 1487 struct bpf_run_ctx *bpf_ctx; 1488 #endif 1489 1490 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK 1491 unsigned long lowest_stack; 1492 unsigned long prev_lowest_stack; 1493 #endif 1494 1495 #ifdef CONFIG_X86_MCE 1496 void __user *mce_vaddr; 1497 __u64 mce_kflags; 1498 u64 mce_addr; 1499 __u64 mce_ripv : 1, 1500 mce_whole_page : 1, 1501 __mce_reserved : 62; 1502 struct callback_head mce_kill_me; 1503 int mce_count; 1504 #endif 1505 1506 #ifdef CONFIG_KRETPROBES 1507 struct llist_head kretprobe_instances; 1508 #endif 1509 #ifdef CONFIG_RETHOOK 1510 struct llist_head rethooks; 1511 #endif 1512 1513 #ifdef CONFIG_ARCH_HAS_PARANOID_L1D_FLUSH 1514 /* 1515 * If L1D flush is supported on mm context switch 1516 * then we use this callback head to queue kill work 1517 * to kill tasks that are not running on SMT disabled 1518 * cores 1519 */ 1520 struct callback_head l1d_flush_kill; 1521 #endif 1522 1523 #ifdef CONFIG_RV 1524 /* 1525 * Per-task RV monitor. Nowadays fixed in RV_PER_TASK_MONITORS. 1526 * If we find justification for more monitors, we can think 1527 * about adding more or developing a dynamic method. So far, 1528 * none of these are justified. 1529 */ 1530 union rv_task_monitor rv[RV_PER_TASK_MONITORS]; 1531 #endif 1532 1533 #ifdef CONFIG_USER_EVENTS 1534 struct user_event_mm *user_event_mm; 1535 #endif 1536 1537 /* 1538 * New fields for task_struct should be added above here, so that 1539 * they are included in the randomized portion of task_struct. 1540 */ 1541 randomized_struct_fields_end 1542 1543 /* CPU-specific state of this task: */ 1544 struct thread_struct thread; 1545 1546 /* 1547 * WARNING: on x86, 'thread_struct' contains a variable-sized 1548 * structure. It *MUST* be at the end of 'task_struct'. 1549 * 1550 * Do not put anything below here! 1551 */ 1552 }; 1553 1554 static inline struct pid *task_pid(struct task_struct *task) 1555 { 1556 return task->thread_pid; 1557 } 1558 1559 /* 1560 * the helpers to get the task's different pids as they are seen 1561 * from various namespaces 1562 * 1563 * task_xid_nr() : global id, i.e. the id seen from the init namespace; 1564 * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of 1565 * current. 1566 * task_xid_nr_ns() : id seen from the ns specified; 1567 * 1568 * see also pid_nr() etc in include/linux/pid.h 1569 */ 1570 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns); 1571 1572 static inline pid_t task_pid_nr(struct task_struct *tsk) 1573 { 1574 return tsk->pid; 1575 } 1576 1577 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1578 { 1579 return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns); 1580 } 1581 1582 static inline pid_t task_pid_vnr(struct task_struct *tsk) 1583 { 1584 return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL); 1585 } 1586 1587 1588 static inline pid_t task_tgid_nr(struct task_struct *tsk) 1589 { 1590 return tsk->tgid; 1591 } 1592 1593 /** 1594 * pid_alive - check that a task structure is not stale 1595 * @p: Task structure to be checked. 1596 * 1597 * Test if a process is not yet dead (at most zombie state) 1598 * If pid_alive fails, then pointers within the task structure 1599 * can be stale and must not be dereferenced. 1600 * 1601 * Return: 1 if the process is alive. 0 otherwise. 1602 */ 1603 static inline int pid_alive(const struct task_struct *p) 1604 { 1605 return p->thread_pid != NULL; 1606 } 1607 1608 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1609 { 1610 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns); 1611 } 1612 1613 static inline pid_t task_pgrp_vnr(struct task_struct *tsk) 1614 { 1615 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL); 1616 } 1617 1618 1619 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1620 { 1621 return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns); 1622 } 1623 1624 static inline pid_t task_session_vnr(struct task_struct *tsk) 1625 { 1626 return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL); 1627 } 1628 1629 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1630 { 1631 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, ns); 1632 } 1633 1634 static inline pid_t task_tgid_vnr(struct task_struct *tsk) 1635 { 1636 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, NULL); 1637 } 1638 1639 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns) 1640 { 1641 pid_t pid = 0; 1642 1643 rcu_read_lock(); 1644 if (pid_alive(tsk)) 1645 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns); 1646 rcu_read_unlock(); 1647 1648 return pid; 1649 } 1650 1651 static inline pid_t task_ppid_nr(const struct task_struct *tsk) 1652 { 1653 return task_ppid_nr_ns(tsk, &init_pid_ns); 1654 } 1655 1656 /* Obsolete, do not use: */ 1657 static inline pid_t task_pgrp_nr(struct task_struct *tsk) 1658 { 1659 return task_pgrp_nr_ns(tsk, &init_pid_ns); 1660 } 1661 1662 #define TASK_REPORT_IDLE (TASK_REPORT + 1) 1663 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1) 1664 1665 static inline unsigned int __task_state_index(unsigned int tsk_state, 1666 unsigned int tsk_exit_state) 1667 { 1668 unsigned int state = (tsk_state | tsk_exit_state) & TASK_REPORT; 1669 1670 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX); 1671 1672 if (tsk_state == TASK_IDLE) 1673 state = TASK_REPORT_IDLE; 1674 1675 /* 1676 * We're lying here, but rather than expose a completely new task state 1677 * to userspace, we can make this appear as if the task has gone through 1678 * a regular rt_mutex_lock() call. 1679 */ 1680 if (tsk_state == TASK_RTLOCK_WAIT) 1681 state = TASK_UNINTERRUPTIBLE; 1682 1683 return fls(state); 1684 } 1685 1686 static inline unsigned int task_state_index(struct task_struct *tsk) 1687 { 1688 return __task_state_index(READ_ONCE(tsk->__state), tsk->exit_state); 1689 } 1690 1691 static inline char task_index_to_char(unsigned int state) 1692 { 1693 static const char state_char[] = "RSDTtXZPI"; 1694 1695 BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1); 1696 1697 return state_char[state]; 1698 } 1699 1700 static inline char task_state_to_char(struct task_struct *tsk) 1701 { 1702 return task_index_to_char(task_state_index(tsk)); 1703 } 1704 1705 /** 1706 * is_global_init - check if a task structure is init. Since init 1707 * is free to have sub-threads we need to check tgid. 1708 * @tsk: Task structure to be checked. 1709 * 1710 * Check if a task structure is the first user space task the kernel created. 1711 * 1712 * Return: 1 if the task structure is init. 0 otherwise. 1713 */ 1714 static inline int is_global_init(struct task_struct *tsk) 1715 { 1716 return task_tgid_nr(tsk) == 1; 1717 } 1718 1719 extern struct pid *cad_pid; 1720 1721 /* 1722 * Per process flags 1723 */ 1724 #define PF_VCPU 0x00000001 /* I'm a virtual CPU */ 1725 #define PF_IDLE 0x00000002 /* I am an IDLE thread */ 1726 #define PF_EXITING 0x00000004 /* Getting shut down */ 1727 #define PF_POSTCOREDUMP 0x00000008 /* Coredumps should ignore this task */ 1728 #define PF_IO_WORKER 0x00000010 /* Task is an IO worker */ 1729 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */ 1730 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */ 1731 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */ 1732 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */ 1733 #define PF_DUMPCORE 0x00000200 /* Dumped core */ 1734 #define PF_SIGNALED 0x00000400 /* Killed by a signal */ 1735 #define PF_MEMALLOC 0x00000800 /* Allocating memory */ 1736 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */ 1737 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */ 1738 #define PF_USER_WORKER 0x00004000 /* Kernel thread cloned from userspace thread */ 1739 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */ 1740 #define PF__HOLE__00010000 0x00010000 1741 #define PF_KSWAPD 0x00020000 /* I am kswapd */ 1742 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocation requests will inherit GFP_NOFS */ 1743 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocation requests will inherit GFP_NOIO */ 1744 #define PF_LOCAL_THROTTLE 0x00100000 /* Throttle writes only against the bdi I write to, 1745 * I am cleaning dirty pages from some other bdi. */ 1746 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */ 1747 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */ 1748 #define PF__HOLE__00800000 0x00800000 1749 #define PF__HOLE__01000000 0x01000000 1750 #define PF__HOLE__02000000 0x02000000 1751 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */ 1752 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */ 1753 #define PF_MEMALLOC_PIN 0x10000000 /* Allocation context constrained to zones which allow long term pinning. */ 1754 #define PF__HOLE__20000000 0x20000000 1755 #define PF__HOLE__40000000 0x40000000 1756 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */ 1757 1758 /* 1759 * Only the _current_ task can read/write to tsk->flags, but other 1760 * tasks can access tsk->flags in readonly mode for example 1761 * with tsk_used_math (like during threaded core dumping). 1762 * There is however an exception to this rule during ptrace 1763 * or during fork: the ptracer task is allowed to write to the 1764 * child->flags of its traced child (same goes for fork, the parent 1765 * can write to the child->flags), because we're guaranteed the 1766 * child is not running and in turn not changing child->flags 1767 * at the same time the parent does it. 1768 */ 1769 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0) 1770 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0) 1771 #define clear_used_math() clear_stopped_child_used_math(current) 1772 #define set_used_math() set_stopped_child_used_math(current) 1773 1774 #define conditional_stopped_child_used_math(condition, child) \ 1775 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0) 1776 1777 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current) 1778 1779 #define copy_to_stopped_child_used_math(child) \ 1780 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0) 1781 1782 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */ 1783 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH) 1784 #define used_math() tsk_used_math(current) 1785 1786 static __always_inline bool is_percpu_thread(void) 1787 { 1788 #ifdef CONFIG_SMP 1789 return (current->flags & PF_NO_SETAFFINITY) && 1790 (current->nr_cpus_allowed == 1); 1791 #else 1792 return true; 1793 #endif 1794 } 1795 1796 /* Per-process atomic flags. */ 1797 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */ 1798 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */ 1799 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */ 1800 #define PFA_SPEC_SSB_DISABLE 3 /* Speculative Store Bypass disabled */ 1801 #define PFA_SPEC_SSB_FORCE_DISABLE 4 /* Speculative Store Bypass force disabled*/ 1802 #define PFA_SPEC_IB_DISABLE 5 /* Indirect branch speculation restricted */ 1803 #define PFA_SPEC_IB_FORCE_DISABLE 6 /* Indirect branch speculation permanently restricted */ 1804 #define PFA_SPEC_SSB_NOEXEC 7 /* Speculative Store Bypass clear on execve() */ 1805 1806 #define TASK_PFA_TEST(name, func) \ 1807 static inline bool task_##func(struct task_struct *p) \ 1808 { return test_bit(PFA_##name, &p->atomic_flags); } 1809 1810 #define TASK_PFA_SET(name, func) \ 1811 static inline void task_set_##func(struct task_struct *p) \ 1812 { set_bit(PFA_##name, &p->atomic_flags); } 1813 1814 #define TASK_PFA_CLEAR(name, func) \ 1815 static inline void task_clear_##func(struct task_struct *p) \ 1816 { clear_bit(PFA_##name, &p->atomic_flags); } 1817 1818 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs) 1819 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs) 1820 1821 TASK_PFA_TEST(SPREAD_PAGE, spread_page) 1822 TASK_PFA_SET(SPREAD_PAGE, spread_page) 1823 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page) 1824 1825 TASK_PFA_TEST(SPREAD_SLAB, spread_slab) 1826 TASK_PFA_SET(SPREAD_SLAB, spread_slab) 1827 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab) 1828 1829 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable) 1830 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable) 1831 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable) 1832 1833 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1834 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1835 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1836 1837 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1838 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1839 1840 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable) 1841 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable) 1842 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable) 1843 1844 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1845 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1846 1847 static inline void 1848 current_restore_flags(unsigned long orig_flags, unsigned long flags) 1849 { 1850 current->flags &= ~flags; 1851 current->flags |= orig_flags & flags; 1852 } 1853 1854 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial); 1855 extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_effective_cpus); 1856 #ifdef CONFIG_SMP 1857 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask); 1858 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask); 1859 extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node); 1860 extern void release_user_cpus_ptr(struct task_struct *p); 1861 extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask); 1862 extern void force_compatible_cpus_allowed_ptr(struct task_struct *p); 1863 extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p); 1864 #else 1865 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) 1866 { 1867 } 1868 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) 1869 { 1870 if (!cpumask_test_cpu(0, new_mask)) 1871 return -EINVAL; 1872 return 0; 1873 } 1874 static inline int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node) 1875 { 1876 if (src->user_cpus_ptr) 1877 return -EINVAL; 1878 return 0; 1879 } 1880 static inline void release_user_cpus_ptr(struct task_struct *p) 1881 { 1882 WARN_ON(p->user_cpus_ptr); 1883 } 1884 1885 static inline int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask) 1886 { 1887 return 0; 1888 } 1889 #endif 1890 1891 extern int yield_to(struct task_struct *p, bool preempt); 1892 extern void set_user_nice(struct task_struct *p, long nice); 1893 extern int task_prio(const struct task_struct *p); 1894 1895 /** 1896 * task_nice - return the nice value of a given task. 1897 * @p: the task in question. 1898 * 1899 * Return: The nice value [ -20 ... 0 ... 19 ]. 1900 */ 1901 static inline int task_nice(const struct task_struct *p) 1902 { 1903 return PRIO_TO_NICE((p)->static_prio); 1904 } 1905 1906 extern int can_nice(const struct task_struct *p, const int nice); 1907 extern int task_curr(const struct task_struct *p); 1908 extern int idle_cpu(int cpu); 1909 extern int available_idle_cpu(int cpu); 1910 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *); 1911 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *); 1912 extern void sched_set_fifo(struct task_struct *p); 1913 extern void sched_set_fifo_low(struct task_struct *p); 1914 extern void sched_set_normal(struct task_struct *p, int nice); 1915 extern int sched_setattr(struct task_struct *, const struct sched_attr *); 1916 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *); 1917 extern struct task_struct *idle_task(int cpu); 1918 1919 /** 1920 * is_idle_task - is the specified task an idle task? 1921 * @p: the task in question. 1922 * 1923 * Return: 1 if @p is an idle task. 0 otherwise. 1924 */ 1925 static __always_inline bool is_idle_task(const struct task_struct *p) 1926 { 1927 return !!(p->flags & PF_IDLE); 1928 } 1929 1930 extern struct task_struct *curr_task(int cpu); 1931 extern void ia64_set_curr_task(int cpu, struct task_struct *p); 1932 1933 void yield(void); 1934 1935 union thread_union { 1936 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK 1937 struct task_struct task; 1938 #endif 1939 #ifndef CONFIG_THREAD_INFO_IN_TASK 1940 struct thread_info thread_info; 1941 #endif 1942 unsigned long stack[THREAD_SIZE/sizeof(long)]; 1943 }; 1944 1945 #ifndef CONFIG_THREAD_INFO_IN_TASK 1946 extern struct thread_info init_thread_info; 1947 #endif 1948 1949 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)]; 1950 1951 #ifdef CONFIG_THREAD_INFO_IN_TASK 1952 # define task_thread_info(task) (&(task)->thread_info) 1953 #elif !defined(__HAVE_THREAD_FUNCTIONS) 1954 # define task_thread_info(task) ((struct thread_info *)(task)->stack) 1955 #endif 1956 1957 /* 1958 * find a task by one of its numerical ids 1959 * 1960 * find_task_by_pid_ns(): 1961 * finds a task by its pid in the specified namespace 1962 * find_task_by_vpid(): 1963 * finds a task by its virtual pid 1964 * 1965 * see also find_vpid() etc in include/linux/pid.h 1966 */ 1967 1968 extern struct task_struct *find_task_by_vpid(pid_t nr); 1969 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns); 1970 1971 /* 1972 * find a task by its virtual pid and get the task struct 1973 */ 1974 extern struct task_struct *find_get_task_by_vpid(pid_t nr); 1975 1976 extern int wake_up_state(struct task_struct *tsk, unsigned int state); 1977 extern int wake_up_process(struct task_struct *tsk); 1978 extern void wake_up_new_task(struct task_struct *tsk); 1979 1980 #ifdef CONFIG_SMP 1981 extern void kick_process(struct task_struct *tsk); 1982 #else 1983 static inline void kick_process(struct task_struct *tsk) { } 1984 #endif 1985 1986 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec); 1987 1988 static inline void set_task_comm(struct task_struct *tsk, const char *from) 1989 { 1990 __set_task_comm(tsk, from, false); 1991 } 1992 1993 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk); 1994 #define get_task_comm(buf, tsk) ({ \ 1995 BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN); \ 1996 __get_task_comm(buf, sizeof(buf), tsk); \ 1997 }) 1998 1999 #ifdef CONFIG_SMP 2000 static __always_inline void scheduler_ipi(void) 2001 { 2002 /* 2003 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting 2004 * TIF_NEED_RESCHED remotely (for the first time) will also send 2005 * this IPI. 2006 */ 2007 preempt_fold_need_resched(); 2008 } 2009 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state); 2010 #else 2011 static inline void scheduler_ipi(void) { } 2012 static inline unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state) 2013 { 2014 return 1; 2015 } 2016 #endif 2017 2018 /* 2019 * Set thread flags in other task's structures. 2020 * See asm/thread_info.h for TIF_xxxx flags available: 2021 */ 2022 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag) 2023 { 2024 set_ti_thread_flag(task_thread_info(tsk), flag); 2025 } 2026 2027 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag) 2028 { 2029 clear_ti_thread_flag(task_thread_info(tsk), flag); 2030 } 2031 2032 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag, 2033 bool value) 2034 { 2035 update_ti_thread_flag(task_thread_info(tsk), flag, value); 2036 } 2037 2038 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag) 2039 { 2040 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag); 2041 } 2042 2043 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag) 2044 { 2045 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag); 2046 } 2047 2048 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag) 2049 { 2050 return test_ti_thread_flag(task_thread_info(tsk), flag); 2051 } 2052 2053 static inline void set_tsk_need_resched(struct task_struct *tsk) 2054 { 2055 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 2056 } 2057 2058 static inline void clear_tsk_need_resched(struct task_struct *tsk) 2059 { 2060 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 2061 } 2062 2063 static inline int test_tsk_need_resched(struct task_struct *tsk) 2064 { 2065 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED)); 2066 } 2067 2068 /* 2069 * cond_resched() and cond_resched_lock(): latency reduction via 2070 * explicit rescheduling in places that are safe. The return 2071 * value indicates whether a reschedule was done in fact. 2072 * cond_resched_lock() will drop the spinlock before scheduling, 2073 */ 2074 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) 2075 extern int __cond_resched(void); 2076 2077 #if defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL) 2078 2079 void sched_dynamic_klp_enable(void); 2080 void sched_dynamic_klp_disable(void); 2081 2082 DECLARE_STATIC_CALL(cond_resched, __cond_resched); 2083 2084 static __always_inline int _cond_resched(void) 2085 { 2086 return static_call_mod(cond_resched)(); 2087 } 2088 2089 #elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY) 2090 2091 extern int dynamic_cond_resched(void); 2092 2093 static __always_inline int _cond_resched(void) 2094 { 2095 return dynamic_cond_resched(); 2096 } 2097 2098 #else /* !CONFIG_PREEMPTION */ 2099 2100 static inline int _cond_resched(void) 2101 { 2102 klp_sched_try_switch(); 2103 return __cond_resched(); 2104 } 2105 2106 #endif /* PREEMPT_DYNAMIC && CONFIG_HAVE_PREEMPT_DYNAMIC_CALL */ 2107 2108 #else /* CONFIG_PREEMPTION && !CONFIG_PREEMPT_DYNAMIC */ 2109 2110 static inline int _cond_resched(void) 2111 { 2112 klp_sched_try_switch(); 2113 return 0; 2114 } 2115 2116 #endif /* !CONFIG_PREEMPTION || CONFIG_PREEMPT_DYNAMIC */ 2117 2118 #define cond_resched() ({ \ 2119 __might_resched(__FILE__, __LINE__, 0); \ 2120 _cond_resched(); \ 2121 }) 2122 2123 extern int __cond_resched_lock(spinlock_t *lock); 2124 extern int __cond_resched_rwlock_read(rwlock_t *lock); 2125 extern int __cond_resched_rwlock_write(rwlock_t *lock); 2126 2127 #define MIGHT_RESCHED_RCU_SHIFT 8 2128 #define MIGHT_RESCHED_PREEMPT_MASK ((1U << MIGHT_RESCHED_RCU_SHIFT) - 1) 2129 2130 #ifndef CONFIG_PREEMPT_RT 2131 /* 2132 * Non RT kernels have an elevated preempt count due to the held lock, 2133 * but are not allowed to be inside a RCU read side critical section 2134 */ 2135 # define PREEMPT_LOCK_RESCHED_OFFSETS PREEMPT_LOCK_OFFSET 2136 #else 2137 /* 2138 * spin/rw_lock() on RT implies rcu_read_lock(). The might_sleep() check in 2139 * cond_resched*lock() has to take that into account because it checks for 2140 * preempt_count() and rcu_preempt_depth(). 2141 */ 2142 # define PREEMPT_LOCK_RESCHED_OFFSETS \ 2143 (PREEMPT_LOCK_OFFSET + (1U << MIGHT_RESCHED_RCU_SHIFT)) 2144 #endif 2145 2146 #define cond_resched_lock(lock) ({ \ 2147 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2148 __cond_resched_lock(lock); \ 2149 }) 2150 2151 #define cond_resched_rwlock_read(lock) ({ \ 2152 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2153 __cond_resched_rwlock_read(lock); \ 2154 }) 2155 2156 #define cond_resched_rwlock_write(lock) ({ \ 2157 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2158 __cond_resched_rwlock_write(lock); \ 2159 }) 2160 2161 static inline void cond_resched_rcu(void) 2162 { 2163 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU) 2164 rcu_read_unlock(); 2165 cond_resched(); 2166 rcu_read_lock(); 2167 #endif 2168 } 2169 2170 #ifdef CONFIG_PREEMPT_DYNAMIC 2171 2172 extern bool preempt_model_none(void); 2173 extern bool preempt_model_voluntary(void); 2174 extern bool preempt_model_full(void); 2175 2176 #else 2177 2178 static inline bool preempt_model_none(void) 2179 { 2180 return IS_ENABLED(CONFIG_PREEMPT_NONE); 2181 } 2182 static inline bool preempt_model_voluntary(void) 2183 { 2184 return IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY); 2185 } 2186 static inline bool preempt_model_full(void) 2187 { 2188 return IS_ENABLED(CONFIG_PREEMPT); 2189 } 2190 2191 #endif 2192 2193 static inline bool preempt_model_rt(void) 2194 { 2195 return IS_ENABLED(CONFIG_PREEMPT_RT); 2196 } 2197 2198 /* 2199 * Does the preemption model allow non-cooperative preemption? 2200 * 2201 * For !CONFIG_PREEMPT_DYNAMIC kernels this is an exact match with 2202 * CONFIG_PREEMPTION; for CONFIG_PREEMPT_DYNAMIC this doesn't work as the 2203 * kernel is *built* with CONFIG_PREEMPTION=y but may run with e.g. the 2204 * PREEMPT_NONE model. 2205 */ 2206 static inline bool preempt_model_preemptible(void) 2207 { 2208 return preempt_model_full() || preempt_model_rt(); 2209 } 2210 2211 /* 2212 * Does a critical section need to be broken due to another 2213 * task waiting?: (technically does not depend on CONFIG_PREEMPTION, 2214 * but a general need for low latency) 2215 */ 2216 static inline int spin_needbreak(spinlock_t *lock) 2217 { 2218 #ifdef CONFIG_PREEMPTION 2219 return spin_is_contended(lock); 2220 #else 2221 return 0; 2222 #endif 2223 } 2224 2225 /* 2226 * Check if a rwlock is contended. 2227 * Returns non-zero if there is another task waiting on the rwlock. 2228 * Returns zero if the lock is not contended or the system / underlying 2229 * rwlock implementation does not support contention detection. 2230 * Technically does not depend on CONFIG_PREEMPTION, but a general need 2231 * for low latency. 2232 */ 2233 static inline int rwlock_needbreak(rwlock_t *lock) 2234 { 2235 #ifdef CONFIG_PREEMPTION 2236 return rwlock_is_contended(lock); 2237 #else 2238 return 0; 2239 #endif 2240 } 2241 2242 static __always_inline bool need_resched(void) 2243 { 2244 return unlikely(tif_need_resched()); 2245 } 2246 2247 /* 2248 * Wrappers for p->thread_info->cpu access. No-op on UP. 2249 */ 2250 #ifdef CONFIG_SMP 2251 2252 static inline unsigned int task_cpu(const struct task_struct *p) 2253 { 2254 return READ_ONCE(task_thread_info(p)->cpu); 2255 } 2256 2257 extern void set_task_cpu(struct task_struct *p, unsigned int cpu); 2258 2259 #else 2260 2261 static inline unsigned int task_cpu(const struct task_struct *p) 2262 { 2263 return 0; 2264 } 2265 2266 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu) 2267 { 2268 } 2269 2270 #endif /* CONFIG_SMP */ 2271 2272 extern bool sched_task_on_rq(struct task_struct *p); 2273 extern unsigned long get_wchan(struct task_struct *p); 2274 extern struct task_struct *cpu_curr_snapshot(int cpu); 2275 2276 /* 2277 * In order to reduce various lock holder preemption latencies provide an 2278 * interface to see if a vCPU is currently running or not. 2279 * 2280 * This allows us to terminate optimistic spin loops and block, analogous to 2281 * the native optimistic spin heuristic of testing if the lock owner task is 2282 * running or not. 2283 */ 2284 #ifndef vcpu_is_preempted 2285 static inline bool vcpu_is_preempted(int cpu) 2286 { 2287 return false; 2288 } 2289 #endif 2290 2291 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask); 2292 extern long sched_getaffinity(pid_t pid, struct cpumask *mask); 2293 2294 #ifndef TASK_SIZE_OF 2295 #define TASK_SIZE_OF(tsk) TASK_SIZE 2296 #endif 2297 2298 #ifdef CONFIG_SMP 2299 static inline bool owner_on_cpu(struct task_struct *owner) 2300 { 2301 /* 2302 * As lock holder preemption issue, we both skip spinning if 2303 * task is not on cpu or its cpu is preempted 2304 */ 2305 return READ_ONCE(owner->on_cpu) && !vcpu_is_preempted(task_cpu(owner)); 2306 } 2307 2308 /* Returns effective CPU energy utilization, as seen by the scheduler */ 2309 unsigned long sched_cpu_util(int cpu); 2310 #endif /* CONFIG_SMP */ 2311 2312 #ifdef CONFIG_RSEQ 2313 2314 /* 2315 * Map the event mask on the user-space ABI enum rseq_cs_flags 2316 * for direct mask checks. 2317 */ 2318 enum rseq_event_mask_bits { 2319 RSEQ_EVENT_PREEMPT_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT, 2320 RSEQ_EVENT_SIGNAL_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT, 2321 RSEQ_EVENT_MIGRATE_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT, 2322 }; 2323 2324 enum rseq_event_mask { 2325 RSEQ_EVENT_PREEMPT = (1U << RSEQ_EVENT_PREEMPT_BIT), 2326 RSEQ_EVENT_SIGNAL = (1U << RSEQ_EVENT_SIGNAL_BIT), 2327 RSEQ_EVENT_MIGRATE = (1U << RSEQ_EVENT_MIGRATE_BIT), 2328 }; 2329 2330 static inline void rseq_set_notify_resume(struct task_struct *t) 2331 { 2332 if (t->rseq) 2333 set_tsk_thread_flag(t, TIF_NOTIFY_RESUME); 2334 } 2335 2336 void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs); 2337 2338 static inline void rseq_handle_notify_resume(struct ksignal *ksig, 2339 struct pt_regs *regs) 2340 { 2341 if (current->rseq) 2342 __rseq_handle_notify_resume(ksig, regs); 2343 } 2344 2345 static inline void rseq_signal_deliver(struct ksignal *ksig, 2346 struct pt_regs *regs) 2347 { 2348 preempt_disable(); 2349 __set_bit(RSEQ_EVENT_SIGNAL_BIT, ¤t->rseq_event_mask); 2350 preempt_enable(); 2351 rseq_handle_notify_resume(ksig, regs); 2352 } 2353 2354 /* rseq_preempt() requires preemption to be disabled. */ 2355 static inline void rseq_preempt(struct task_struct *t) 2356 { 2357 __set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask); 2358 rseq_set_notify_resume(t); 2359 } 2360 2361 /* rseq_migrate() requires preemption to be disabled. */ 2362 static inline void rseq_migrate(struct task_struct *t) 2363 { 2364 __set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask); 2365 rseq_set_notify_resume(t); 2366 } 2367 2368 /* 2369 * If parent process has a registered restartable sequences area, the 2370 * child inherits. Unregister rseq for a clone with CLONE_VM set. 2371 */ 2372 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags) 2373 { 2374 if (clone_flags & CLONE_VM) { 2375 t->rseq = NULL; 2376 t->rseq_len = 0; 2377 t->rseq_sig = 0; 2378 t->rseq_event_mask = 0; 2379 } else { 2380 t->rseq = current->rseq; 2381 t->rseq_len = current->rseq_len; 2382 t->rseq_sig = current->rseq_sig; 2383 t->rseq_event_mask = current->rseq_event_mask; 2384 } 2385 } 2386 2387 static inline void rseq_execve(struct task_struct *t) 2388 { 2389 t->rseq = NULL; 2390 t->rseq_len = 0; 2391 t->rseq_sig = 0; 2392 t->rseq_event_mask = 0; 2393 } 2394 2395 #else 2396 2397 static inline void rseq_set_notify_resume(struct task_struct *t) 2398 { 2399 } 2400 static inline void rseq_handle_notify_resume(struct ksignal *ksig, 2401 struct pt_regs *regs) 2402 { 2403 } 2404 static inline void rseq_signal_deliver(struct ksignal *ksig, 2405 struct pt_regs *regs) 2406 { 2407 } 2408 static inline void rseq_preempt(struct task_struct *t) 2409 { 2410 } 2411 static inline void rseq_migrate(struct task_struct *t) 2412 { 2413 } 2414 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags) 2415 { 2416 } 2417 static inline void rseq_execve(struct task_struct *t) 2418 { 2419 } 2420 2421 #endif 2422 2423 #ifdef CONFIG_DEBUG_RSEQ 2424 2425 void rseq_syscall(struct pt_regs *regs); 2426 2427 #else 2428 2429 static inline void rseq_syscall(struct pt_regs *regs) 2430 { 2431 } 2432 2433 #endif 2434 2435 #ifdef CONFIG_SCHED_CORE 2436 extern void sched_core_free(struct task_struct *tsk); 2437 extern void sched_core_fork(struct task_struct *p); 2438 extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type, 2439 unsigned long uaddr); 2440 #else 2441 static inline void sched_core_free(struct task_struct *tsk) { } 2442 static inline void sched_core_fork(struct task_struct *p) { } 2443 #endif 2444 2445 extern void sched_set_stop_task(int cpu, struct task_struct *stop); 2446 2447 #endif 2448