1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _LINUX_SCHED_H 3 #define _LINUX_SCHED_H 4 5 /* 6 * Define 'struct task_struct' and provide the main scheduler 7 * APIs (schedule(), wakeup variants, etc.) 8 */ 9 10 #include <uapi/linux/sched.h> 11 12 #include <asm/current.h> 13 14 #include <linux/pid.h> 15 #include <linux/sem.h> 16 #include <linux/shm.h> 17 #include <linux/mutex.h> 18 #include <linux/plist.h> 19 #include <linux/hrtimer.h> 20 #include <linux/irqflags.h> 21 #include <linux/seccomp.h> 22 #include <linux/nodemask.h> 23 #include <linux/rcupdate.h> 24 #include <linux/refcount.h> 25 #include <linux/resource.h> 26 #include <linux/latencytop.h> 27 #include <linux/sched/prio.h> 28 #include <linux/sched/types.h> 29 #include <linux/signal_types.h> 30 #include <linux/syscall_user_dispatch.h> 31 #include <linux/mm_types_task.h> 32 #include <linux/task_io_accounting.h> 33 #include <linux/posix-timers.h> 34 #include <linux/rseq.h> 35 #include <linux/seqlock.h> 36 #include <linux/kcsan.h> 37 #include <linux/rv.h> 38 #include <asm/kmap_size.h> 39 40 /* task_struct member predeclarations (sorted alphabetically): */ 41 struct audit_context; 42 struct backing_dev_info; 43 struct bio_list; 44 struct blk_plug; 45 struct bpf_local_storage; 46 struct bpf_run_ctx; 47 struct capture_control; 48 struct cfs_rq; 49 struct fs_struct; 50 struct futex_pi_state; 51 struct io_context; 52 struct io_uring_task; 53 struct mempolicy; 54 struct nameidata; 55 struct nsproxy; 56 struct perf_event_context; 57 struct pid_namespace; 58 struct pipe_inode_info; 59 struct rcu_node; 60 struct reclaim_state; 61 struct robust_list_head; 62 struct root_domain; 63 struct rq; 64 struct sched_attr; 65 struct sched_param; 66 struct seq_file; 67 struct sighand_struct; 68 struct signal_struct; 69 struct task_delay_info; 70 struct task_group; 71 72 /* 73 * Task state bitmask. NOTE! These bits are also 74 * encoded in fs/proc/array.c: get_task_state(). 75 * 76 * We have two separate sets of flags: task->state 77 * is about runnability, while task->exit_state are 78 * about the task exiting. Confusing, but this way 79 * modifying one set can't modify the other one by 80 * mistake. 81 */ 82 83 /* Used in tsk->state: */ 84 #define TASK_RUNNING 0x00000000 85 #define TASK_INTERRUPTIBLE 0x00000001 86 #define TASK_UNINTERRUPTIBLE 0x00000002 87 #define __TASK_STOPPED 0x00000004 88 #define __TASK_TRACED 0x00000008 89 /* Used in tsk->exit_state: */ 90 #define EXIT_DEAD 0x00000010 91 #define EXIT_ZOMBIE 0x00000020 92 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD) 93 /* Used in tsk->state again: */ 94 #define TASK_PARKED 0x00000040 95 #define TASK_DEAD 0x00000080 96 #define TASK_WAKEKILL 0x00000100 97 #define TASK_WAKING 0x00000200 98 #define TASK_NOLOAD 0x00000400 99 #define TASK_NEW 0x00000800 100 #define TASK_RTLOCK_WAIT 0x00001000 101 #define TASK_FREEZABLE 0x00002000 102 #define __TASK_FREEZABLE_UNSAFE (0x00004000 * IS_ENABLED(CONFIG_LOCKDEP)) 103 #define TASK_FROZEN 0x00008000 104 #define TASK_STATE_MAX 0x00010000 105 106 #define TASK_ANY (TASK_STATE_MAX-1) 107 108 /* 109 * DO NOT ADD ANY NEW USERS ! 110 */ 111 #define TASK_FREEZABLE_UNSAFE (TASK_FREEZABLE | __TASK_FREEZABLE_UNSAFE) 112 113 /* Convenience macros for the sake of set_current_state: */ 114 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE) 115 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED) 116 #define TASK_TRACED __TASK_TRACED 117 118 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD) 119 120 /* Convenience macros for the sake of wake_up(): */ 121 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE) 122 123 /* get_task_state(): */ 124 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \ 125 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \ 126 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \ 127 TASK_PARKED) 128 129 #define task_is_running(task) (READ_ONCE((task)->__state) == TASK_RUNNING) 130 131 #define task_is_traced(task) ((READ_ONCE(task->jobctl) & JOBCTL_TRACED) != 0) 132 #define task_is_stopped(task) ((READ_ONCE(task->jobctl) & JOBCTL_STOPPED) != 0) 133 #define task_is_stopped_or_traced(task) ((READ_ONCE(task->jobctl) & (JOBCTL_STOPPED | JOBCTL_TRACED)) != 0) 134 135 /* 136 * Special states are those that do not use the normal wait-loop pattern. See 137 * the comment with set_special_state(). 138 */ 139 #define is_special_task_state(state) \ 140 ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD)) 141 142 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 143 # define debug_normal_state_change(state_value) \ 144 do { \ 145 WARN_ON_ONCE(is_special_task_state(state_value)); \ 146 current->task_state_change = _THIS_IP_; \ 147 } while (0) 148 149 # define debug_special_state_change(state_value) \ 150 do { \ 151 WARN_ON_ONCE(!is_special_task_state(state_value)); \ 152 current->task_state_change = _THIS_IP_; \ 153 } while (0) 154 155 # define debug_rtlock_wait_set_state() \ 156 do { \ 157 current->saved_state_change = current->task_state_change;\ 158 current->task_state_change = _THIS_IP_; \ 159 } while (0) 160 161 # define debug_rtlock_wait_restore_state() \ 162 do { \ 163 current->task_state_change = current->saved_state_change;\ 164 } while (0) 165 166 #else 167 # define debug_normal_state_change(cond) do { } while (0) 168 # define debug_special_state_change(cond) do { } while (0) 169 # define debug_rtlock_wait_set_state() do { } while (0) 170 # define debug_rtlock_wait_restore_state() do { } while (0) 171 #endif 172 173 /* 174 * set_current_state() includes a barrier so that the write of current->state 175 * is correctly serialised wrt the caller's subsequent test of whether to 176 * actually sleep: 177 * 178 * for (;;) { 179 * set_current_state(TASK_UNINTERRUPTIBLE); 180 * if (CONDITION) 181 * break; 182 * 183 * schedule(); 184 * } 185 * __set_current_state(TASK_RUNNING); 186 * 187 * If the caller does not need such serialisation (because, for instance, the 188 * CONDITION test and condition change and wakeup are under the same lock) then 189 * use __set_current_state(). 190 * 191 * The above is typically ordered against the wakeup, which does: 192 * 193 * CONDITION = 1; 194 * wake_up_state(p, TASK_UNINTERRUPTIBLE); 195 * 196 * where wake_up_state()/try_to_wake_up() executes a full memory barrier before 197 * accessing p->state. 198 * 199 * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is, 200 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a 201 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING). 202 * 203 * However, with slightly different timing the wakeup TASK_RUNNING store can 204 * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not 205 * a problem either because that will result in one extra go around the loop 206 * and our @cond test will save the day. 207 * 208 * Also see the comments of try_to_wake_up(). 209 */ 210 #define __set_current_state(state_value) \ 211 do { \ 212 debug_normal_state_change((state_value)); \ 213 WRITE_ONCE(current->__state, (state_value)); \ 214 } while (0) 215 216 #define set_current_state(state_value) \ 217 do { \ 218 debug_normal_state_change((state_value)); \ 219 smp_store_mb(current->__state, (state_value)); \ 220 } while (0) 221 222 /* 223 * set_special_state() should be used for those states when the blocking task 224 * can not use the regular condition based wait-loop. In that case we must 225 * serialize against wakeups such that any possible in-flight TASK_RUNNING 226 * stores will not collide with our state change. 227 */ 228 #define set_special_state(state_value) \ 229 do { \ 230 unsigned long flags; /* may shadow */ \ 231 \ 232 raw_spin_lock_irqsave(¤t->pi_lock, flags); \ 233 debug_special_state_change((state_value)); \ 234 WRITE_ONCE(current->__state, (state_value)); \ 235 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \ 236 } while (0) 237 238 /* 239 * PREEMPT_RT specific variants for "sleeping" spin/rwlocks 240 * 241 * RT's spin/rwlock substitutions are state preserving. The state of the 242 * task when blocking on the lock is saved in task_struct::saved_state and 243 * restored after the lock has been acquired. These operations are 244 * serialized by task_struct::pi_lock against try_to_wake_up(). Any non RT 245 * lock related wakeups while the task is blocked on the lock are 246 * redirected to operate on task_struct::saved_state to ensure that these 247 * are not dropped. On restore task_struct::saved_state is set to 248 * TASK_RUNNING so any wakeup attempt redirected to saved_state will fail. 249 * 250 * The lock operation looks like this: 251 * 252 * current_save_and_set_rtlock_wait_state(); 253 * for (;;) { 254 * if (try_lock()) 255 * break; 256 * raw_spin_unlock_irq(&lock->wait_lock); 257 * schedule_rtlock(); 258 * raw_spin_lock_irq(&lock->wait_lock); 259 * set_current_state(TASK_RTLOCK_WAIT); 260 * } 261 * current_restore_rtlock_saved_state(); 262 */ 263 #define current_save_and_set_rtlock_wait_state() \ 264 do { \ 265 lockdep_assert_irqs_disabled(); \ 266 raw_spin_lock(¤t->pi_lock); \ 267 current->saved_state = current->__state; \ 268 debug_rtlock_wait_set_state(); \ 269 WRITE_ONCE(current->__state, TASK_RTLOCK_WAIT); \ 270 raw_spin_unlock(¤t->pi_lock); \ 271 } while (0); 272 273 #define current_restore_rtlock_saved_state() \ 274 do { \ 275 lockdep_assert_irqs_disabled(); \ 276 raw_spin_lock(¤t->pi_lock); \ 277 debug_rtlock_wait_restore_state(); \ 278 WRITE_ONCE(current->__state, current->saved_state); \ 279 current->saved_state = TASK_RUNNING; \ 280 raw_spin_unlock(¤t->pi_lock); \ 281 } while (0); 282 283 #define get_current_state() READ_ONCE(current->__state) 284 285 /* 286 * Define the task command name length as enum, then it can be visible to 287 * BPF programs. 288 */ 289 enum { 290 TASK_COMM_LEN = 16, 291 }; 292 293 extern void scheduler_tick(void); 294 295 #define MAX_SCHEDULE_TIMEOUT LONG_MAX 296 297 extern long schedule_timeout(long timeout); 298 extern long schedule_timeout_interruptible(long timeout); 299 extern long schedule_timeout_killable(long timeout); 300 extern long schedule_timeout_uninterruptible(long timeout); 301 extern long schedule_timeout_idle(long timeout); 302 asmlinkage void schedule(void); 303 extern void schedule_preempt_disabled(void); 304 asmlinkage void preempt_schedule_irq(void); 305 #ifdef CONFIG_PREEMPT_RT 306 extern void schedule_rtlock(void); 307 #endif 308 309 extern int __must_check io_schedule_prepare(void); 310 extern void io_schedule_finish(int token); 311 extern long io_schedule_timeout(long timeout); 312 extern void io_schedule(void); 313 314 /** 315 * struct prev_cputime - snapshot of system and user cputime 316 * @utime: time spent in user mode 317 * @stime: time spent in system mode 318 * @lock: protects the above two fields 319 * 320 * Stores previous user/system time values such that we can guarantee 321 * monotonicity. 322 */ 323 struct prev_cputime { 324 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE 325 u64 utime; 326 u64 stime; 327 raw_spinlock_t lock; 328 #endif 329 }; 330 331 enum vtime_state { 332 /* Task is sleeping or running in a CPU with VTIME inactive: */ 333 VTIME_INACTIVE = 0, 334 /* Task is idle */ 335 VTIME_IDLE, 336 /* Task runs in kernelspace in a CPU with VTIME active: */ 337 VTIME_SYS, 338 /* Task runs in userspace in a CPU with VTIME active: */ 339 VTIME_USER, 340 /* Task runs as guests in a CPU with VTIME active: */ 341 VTIME_GUEST, 342 }; 343 344 struct vtime { 345 seqcount_t seqcount; 346 unsigned long long starttime; 347 enum vtime_state state; 348 unsigned int cpu; 349 u64 utime; 350 u64 stime; 351 u64 gtime; 352 }; 353 354 /* 355 * Utilization clamp constraints. 356 * @UCLAMP_MIN: Minimum utilization 357 * @UCLAMP_MAX: Maximum utilization 358 * @UCLAMP_CNT: Utilization clamp constraints count 359 */ 360 enum uclamp_id { 361 UCLAMP_MIN = 0, 362 UCLAMP_MAX, 363 UCLAMP_CNT 364 }; 365 366 #ifdef CONFIG_SMP 367 extern struct root_domain def_root_domain; 368 extern struct mutex sched_domains_mutex; 369 #endif 370 371 struct sched_info { 372 #ifdef CONFIG_SCHED_INFO 373 /* Cumulative counters: */ 374 375 /* # of times we have run on this CPU: */ 376 unsigned long pcount; 377 378 /* Time spent waiting on a runqueue: */ 379 unsigned long long run_delay; 380 381 /* Timestamps: */ 382 383 /* When did we last run on a CPU? */ 384 unsigned long long last_arrival; 385 386 /* When were we last queued to run? */ 387 unsigned long long last_queued; 388 389 #endif /* CONFIG_SCHED_INFO */ 390 }; 391 392 /* 393 * Integer metrics need fixed point arithmetic, e.g., sched/fair 394 * has a few: load, load_avg, util_avg, freq, and capacity. 395 * 396 * We define a basic fixed point arithmetic range, and then formalize 397 * all these metrics based on that basic range. 398 */ 399 # define SCHED_FIXEDPOINT_SHIFT 10 400 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT) 401 402 /* Increase resolution of cpu_capacity calculations */ 403 # define SCHED_CAPACITY_SHIFT SCHED_FIXEDPOINT_SHIFT 404 # define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT) 405 406 struct load_weight { 407 unsigned long weight; 408 u32 inv_weight; 409 }; 410 411 /** 412 * struct util_est - Estimation utilization of FAIR tasks 413 * @enqueued: instantaneous estimated utilization of a task/cpu 414 * @ewma: the Exponential Weighted Moving Average (EWMA) 415 * utilization of a task 416 * 417 * Support data structure to track an Exponential Weighted Moving Average 418 * (EWMA) of a FAIR task's utilization. New samples are added to the moving 419 * average each time a task completes an activation. Sample's weight is chosen 420 * so that the EWMA will be relatively insensitive to transient changes to the 421 * task's workload. 422 * 423 * The enqueued attribute has a slightly different meaning for tasks and cpus: 424 * - task: the task's util_avg at last task dequeue time 425 * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU 426 * Thus, the util_est.enqueued of a task represents the contribution on the 427 * estimated utilization of the CPU where that task is currently enqueued. 428 * 429 * Only for tasks we track a moving average of the past instantaneous 430 * estimated utilization. This allows to absorb sporadic drops in utilization 431 * of an otherwise almost periodic task. 432 * 433 * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg 434 * updates. When a task is dequeued, its util_est should not be updated if its 435 * util_avg has not been updated in the meantime. 436 * This information is mapped into the MSB bit of util_est.enqueued at dequeue 437 * time. Since max value of util_est.enqueued for a task is 1024 (PELT util_avg 438 * for a task) it is safe to use MSB. 439 */ 440 struct util_est { 441 unsigned int enqueued; 442 unsigned int ewma; 443 #define UTIL_EST_WEIGHT_SHIFT 2 444 #define UTIL_AVG_UNCHANGED 0x80000000 445 } __attribute__((__aligned__(sizeof(u64)))); 446 447 /* 448 * The load/runnable/util_avg accumulates an infinite geometric series 449 * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c). 450 * 451 * [load_avg definition] 452 * 453 * load_avg = runnable% * scale_load_down(load) 454 * 455 * [runnable_avg definition] 456 * 457 * runnable_avg = runnable% * SCHED_CAPACITY_SCALE 458 * 459 * [util_avg definition] 460 * 461 * util_avg = running% * SCHED_CAPACITY_SCALE 462 * 463 * where runnable% is the time ratio that a sched_entity is runnable and 464 * running% the time ratio that a sched_entity is running. 465 * 466 * For cfs_rq, they are the aggregated values of all runnable and blocked 467 * sched_entities. 468 * 469 * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU 470 * capacity scaling. The scaling is done through the rq_clock_pelt that is used 471 * for computing those signals (see update_rq_clock_pelt()) 472 * 473 * N.B., the above ratios (runnable% and running%) themselves are in the 474 * range of [0, 1]. To do fixed point arithmetics, we therefore scale them 475 * to as large a range as necessary. This is for example reflected by 476 * util_avg's SCHED_CAPACITY_SCALE. 477 * 478 * [Overflow issue] 479 * 480 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities 481 * with the highest load (=88761), always runnable on a single cfs_rq, 482 * and should not overflow as the number already hits PID_MAX_LIMIT. 483 * 484 * For all other cases (including 32-bit kernels), struct load_weight's 485 * weight will overflow first before we do, because: 486 * 487 * Max(load_avg) <= Max(load.weight) 488 * 489 * Then it is the load_weight's responsibility to consider overflow 490 * issues. 491 */ 492 struct sched_avg { 493 u64 last_update_time; 494 u64 load_sum; 495 u64 runnable_sum; 496 u32 util_sum; 497 u32 period_contrib; 498 unsigned long load_avg; 499 unsigned long runnable_avg; 500 unsigned long util_avg; 501 struct util_est util_est; 502 } ____cacheline_aligned; 503 504 struct sched_statistics { 505 #ifdef CONFIG_SCHEDSTATS 506 u64 wait_start; 507 u64 wait_max; 508 u64 wait_count; 509 u64 wait_sum; 510 u64 iowait_count; 511 u64 iowait_sum; 512 513 u64 sleep_start; 514 u64 sleep_max; 515 s64 sum_sleep_runtime; 516 517 u64 block_start; 518 u64 block_max; 519 s64 sum_block_runtime; 520 521 u64 exec_max; 522 u64 slice_max; 523 524 u64 nr_migrations_cold; 525 u64 nr_failed_migrations_affine; 526 u64 nr_failed_migrations_running; 527 u64 nr_failed_migrations_hot; 528 u64 nr_forced_migrations; 529 530 u64 nr_wakeups; 531 u64 nr_wakeups_sync; 532 u64 nr_wakeups_migrate; 533 u64 nr_wakeups_local; 534 u64 nr_wakeups_remote; 535 u64 nr_wakeups_affine; 536 u64 nr_wakeups_affine_attempts; 537 u64 nr_wakeups_passive; 538 u64 nr_wakeups_idle; 539 540 #ifdef CONFIG_SCHED_CORE 541 u64 core_forceidle_sum; 542 #endif 543 #endif /* CONFIG_SCHEDSTATS */ 544 } ____cacheline_aligned; 545 546 struct sched_entity { 547 /* For load-balancing: */ 548 struct load_weight load; 549 struct rb_node run_node; 550 struct list_head group_node; 551 unsigned int on_rq; 552 553 u64 exec_start; 554 u64 sum_exec_runtime; 555 u64 vruntime; 556 u64 prev_sum_exec_runtime; 557 558 u64 nr_migrations; 559 560 #ifdef CONFIG_FAIR_GROUP_SCHED 561 int depth; 562 struct sched_entity *parent; 563 /* rq on which this entity is (to be) queued: */ 564 struct cfs_rq *cfs_rq; 565 /* rq "owned" by this entity/group: */ 566 struct cfs_rq *my_q; 567 /* cached value of my_q->h_nr_running */ 568 unsigned long runnable_weight; 569 #endif 570 571 #ifdef CONFIG_SMP 572 /* 573 * Per entity load average tracking. 574 * 575 * Put into separate cache line so it does not 576 * collide with read-mostly values above. 577 */ 578 struct sched_avg avg; 579 #endif 580 }; 581 582 struct sched_rt_entity { 583 struct list_head run_list; 584 unsigned long timeout; 585 unsigned long watchdog_stamp; 586 unsigned int time_slice; 587 unsigned short on_rq; 588 unsigned short on_list; 589 590 struct sched_rt_entity *back; 591 #ifdef CONFIG_RT_GROUP_SCHED 592 struct sched_rt_entity *parent; 593 /* rq on which this entity is (to be) queued: */ 594 struct rt_rq *rt_rq; 595 /* rq "owned" by this entity/group: */ 596 struct rt_rq *my_q; 597 #endif 598 } __randomize_layout; 599 600 struct sched_dl_entity { 601 struct rb_node rb_node; 602 603 /* 604 * Original scheduling parameters. Copied here from sched_attr 605 * during sched_setattr(), they will remain the same until 606 * the next sched_setattr(). 607 */ 608 u64 dl_runtime; /* Maximum runtime for each instance */ 609 u64 dl_deadline; /* Relative deadline of each instance */ 610 u64 dl_period; /* Separation of two instances (period) */ 611 u64 dl_bw; /* dl_runtime / dl_period */ 612 u64 dl_density; /* dl_runtime / dl_deadline */ 613 614 /* 615 * Actual scheduling parameters. Initialized with the values above, 616 * they are continuously updated during task execution. Note that 617 * the remaining runtime could be < 0 in case we are in overrun. 618 */ 619 s64 runtime; /* Remaining runtime for this instance */ 620 u64 deadline; /* Absolute deadline for this instance */ 621 unsigned int flags; /* Specifying the scheduler behaviour */ 622 623 /* 624 * Some bool flags: 625 * 626 * @dl_throttled tells if we exhausted the runtime. If so, the 627 * task has to wait for a replenishment to be performed at the 628 * next firing of dl_timer. 629 * 630 * @dl_yielded tells if task gave up the CPU before consuming 631 * all its available runtime during the last job. 632 * 633 * @dl_non_contending tells if the task is inactive while still 634 * contributing to the active utilization. In other words, it 635 * indicates if the inactive timer has been armed and its handler 636 * has not been executed yet. This flag is useful to avoid race 637 * conditions between the inactive timer handler and the wakeup 638 * code. 639 * 640 * @dl_overrun tells if the task asked to be informed about runtime 641 * overruns. 642 */ 643 unsigned int dl_throttled : 1; 644 unsigned int dl_yielded : 1; 645 unsigned int dl_non_contending : 1; 646 unsigned int dl_overrun : 1; 647 648 /* 649 * Bandwidth enforcement timer. Each -deadline task has its 650 * own bandwidth to be enforced, thus we need one timer per task. 651 */ 652 struct hrtimer dl_timer; 653 654 /* 655 * Inactive timer, responsible for decreasing the active utilization 656 * at the "0-lag time". When a -deadline task blocks, it contributes 657 * to GRUB's active utilization until the "0-lag time", hence a 658 * timer is needed to decrease the active utilization at the correct 659 * time. 660 */ 661 struct hrtimer inactive_timer; 662 663 #ifdef CONFIG_RT_MUTEXES 664 /* 665 * Priority Inheritance. When a DEADLINE scheduling entity is boosted 666 * pi_se points to the donor, otherwise points to the dl_se it belongs 667 * to (the original one/itself). 668 */ 669 struct sched_dl_entity *pi_se; 670 #endif 671 }; 672 673 #ifdef CONFIG_UCLAMP_TASK 674 /* Number of utilization clamp buckets (shorter alias) */ 675 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT 676 677 /* 678 * Utilization clamp for a scheduling entity 679 * @value: clamp value "assigned" to a se 680 * @bucket_id: bucket index corresponding to the "assigned" value 681 * @active: the se is currently refcounted in a rq's bucket 682 * @user_defined: the requested clamp value comes from user-space 683 * 684 * The bucket_id is the index of the clamp bucket matching the clamp value 685 * which is pre-computed and stored to avoid expensive integer divisions from 686 * the fast path. 687 * 688 * The active bit is set whenever a task has got an "effective" value assigned, 689 * which can be different from the clamp value "requested" from user-space. 690 * This allows to know a task is refcounted in the rq's bucket corresponding 691 * to the "effective" bucket_id. 692 * 693 * The user_defined bit is set whenever a task has got a task-specific clamp 694 * value requested from userspace, i.e. the system defaults apply to this task 695 * just as a restriction. This allows to relax default clamps when a less 696 * restrictive task-specific value has been requested, thus allowing to 697 * implement a "nice" semantic. For example, a task running with a 20% 698 * default boost can still drop its own boosting to 0%. 699 */ 700 struct uclamp_se { 701 unsigned int value : bits_per(SCHED_CAPACITY_SCALE); 702 unsigned int bucket_id : bits_per(UCLAMP_BUCKETS); 703 unsigned int active : 1; 704 unsigned int user_defined : 1; 705 }; 706 #endif /* CONFIG_UCLAMP_TASK */ 707 708 union rcu_special { 709 struct { 710 u8 blocked; 711 u8 need_qs; 712 u8 exp_hint; /* Hint for performance. */ 713 u8 need_mb; /* Readers need smp_mb(). */ 714 } b; /* Bits. */ 715 u32 s; /* Set of bits. */ 716 }; 717 718 enum perf_event_task_context { 719 perf_invalid_context = -1, 720 perf_hw_context = 0, 721 perf_sw_context, 722 perf_nr_task_contexts, 723 }; 724 725 struct wake_q_node { 726 struct wake_q_node *next; 727 }; 728 729 struct kmap_ctrl { 730 #ifdef CONFIG_KMAP_LOCAL 731 int idx; 732 pte_t pteval[KM_MAX_IDX]; 733 #endif 734 }; 735 736 struct task_struct { 737 #ifdef CONFIG_THREAD_INFO_IN_TASK 738 /* 739 * For reasons of header soup (see current_thread_info()), this 740 * must be the first element of task_struct. 741 */ 742 struct thread_info thread_info; 743 #endif 744 unsigned int __state; 745 746 #ifdef CONFIG_PREEMPT_RT 747 /* saved state for "spinlock sleepers" */ 748 unsigned int saved_state; 749 #endif 750 751 /* 752 * This begins the randomizable portion of task_struct. Only 753 * scheduling-critical items should be added above here. 754 */ 755 randomized_struct_fields_start 756 757 void *stack; 758 refcount_t usage; 759 /* Per task flags (PF_*), defined further below: */ 760 unsigned int flags; 761 unsigned int ptrace; 762 763 #ifdef CONFIG_SMP 764 int on_cpu; 765 struct __call_single_node wake_entry; 766 unsigned int wakee_flips; 767 unsigned long wakee_flip_decay_ts; 768 struct task_struct *last_wakee; 769 770 /* 771 * recent_used_cpu is initially set as the last CPU used by a task 772 * that wakes affine another task. Waker/wakee relationships can 773 * push tasks around a CPU where each wakeup moves to the next one. 774 * Tracking a recently used CPU allows a quick search for a recently 775 * used CPU that may be idle. 776 */ 777 int recent_used_cpu; 778 int wake_cpu; 779 #endif 780 int on_rq; 781 782 int prio; 783 int static_prio; 784 int normal_prio; 785 unsigned int rt_priority; 786 787 struct sched_entity se; 788 struct sched_rt_entity rt; 789 struct sched_dl_entity dl; 790 const struct sched_class *sched_class; 791 792 #ifdef CONFIG_SCHED_CORE 793 struct rb_node core_node; 794 unsigned long core_cookie; 795 unsigned int core_occupation; 796 #endif 797 798 #ifdef CONFIG_CGROUP_SCHED 799 struct task_group *sched_task_group; 800 #endif 801 802 #ifdef CONFIG_UCLAMP_TASK 803 /* 804 * Clamp values requested for a scheduling entity. 805 * Must be updated with task_rq_lock() held. 806 */ 807 struct uclamp_se uclamp_req[UCLAMP_CNT]; 808 /* 809 * Effective clamp values used for a scheduling entity. 810 * Must be updated with task_rq_lock() held. 811 */ 812 struct uclamp_se uclamp[UCLAMP_CNT]; 813 #endif 814 815 struct sched_statistics stats; 816 817 #ifdef CONFIG_PREEMPT_NOTIFIERS 818 /* List of struct preempt_notifier: */ 819 struct hlist_head preempt_notifiers; 820 #endif 821 822 #ifdef CONFIG_BLK_DEV_IO_TRACE 823 unsigned int btrace_seq; 824 #endif 825 826 unsigned int policy; 827 int nr_cpus_allowed; 828 const cpumask_t *cpus_ptr; 829 cpumask_t *user_cpus_ptr; 830 cpumask_t cpus_mask; 831 void *migration_pending; 832 #ifdef CONFIG_SMP 833 unsigned short migration_disabled; 834 #endif 835 unsigned short migration_flags; 836 837 #ifdef CONFIG_PREEMPT_RCU 838 int rcu_read_lock_nesting; 839 union rcu_special rcu_read_unlock_special; 840 struct list_head rcu_node_entry; 841 struct rcu_node *rcu_blocked_node; 842 #endif /* #ifdef CONFIG_PREEMPT_RCU */ 843 844 #ifdef CONFIG_TASKS_RCU 845 unsigned long rcu_tasks_nvcsw; 846 u8 rcu_tasks_holdout; 847 u8 rcu_tasks_idx; 848 int rcu_tasks_idle_cpu; 849 struct list_head rcu_tasks_holdout_list; 850 #endif /* #ifdef CONFIG_TASKS_RCU */ 851 852 #ifdef CONFIG_TASKS_TRACE_RCU 853 int trc_reader_nesting; 854 int trc_ipi_to_cpu; 855 union rcu_special trc_reader_special; 856 struct list_head trc_holdout_list; 857 struct list_head trc_blkd_node; 858 int trc_blkd_cpu; 859 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */ 860 861 struct sched_info sched_info; 862 863 struct list_head tasks; 864 #ifdef CONFIG_SMP 865 struct plist_node pushable_tasks; 866 struct rb_node pushable_dl_tasks; 867 #endif 868 869 struct mm_struct *mm; 870 struct mm_struct *active_mm; 871 872 /* Per-thread vma caching: */ 873 struct vmacache vmacache; 874 875 #ifdef SPLIT_RSS_COUNTING 876 struct task_rss_stat rss_stat; 877 #endif 878 int exit_state; 879 int exit_code; 880 int exit_signal; 881 /* The signal sent when the parent dies: */ 882 int pdeath_signal; 883 /* JOBCTL_*, siglock protected: */ 884 unsigned long jobctl; 885 886 /* Used for emulating ABI behavior of previous Linux versions: */ 887 unsigned int personality; 888 889 /* Scheduler bits, serialized by scheduler locks: */ 890 unsigned sched_reset_on_fork:1; 891 unsigned sched_contributes_to_load:1; 892 unsigned sched_migrated:1; 893 #ifdef CONFIG_PSI 894 unsigned sched_psi_wake_requeue:1; 895 #endif 896 897 /* Force alignment to the next boundary: */ 898 unsigned :0; 899 900 /* Unserialized, strictly 'current' */ 901 902 /* 903 * This field must not be in the scheduler word above due to wakelist 904 * queueing no longer being serialized by p->on_cpu. However: 905 * 906 * p->XXX = X; ttwu() 907 * schedule() if (p->on_rq && ..) // false 908 * smp_mb__after_spinlock(); if (smp_load_acquire(&p->on_cpu) && //true 909 * deactivate_task() ttwu_queue_wakelist()) 910 * p->on_rq = 0; p->sched_remote_wakeup = Y; 911 * 912 * guarantees all stores of 'current' are visible before 913 * ->sched_remote_wakeup gets used, so it can be in this word. 914 */ 915 unsigned sched_remote_wakeup:1; 916 917 /* Bit to tell LSMs we're in execve(): */ 918 unsigned in_execve:1; 919 unsigned in_iowait:1; 920 #ifndef TIF_RESTORE_SIGMASK 921 unsigned restore_sigmask:1; 922 #endif 923 #ifdef CONFIG_MEMCG 924 unsigned in_user_fault:1; 925 #endif 926 #ifdef CONFIG_COMPAT_BRK 927 unsigned brk_randomized:1; 928 #endif 929 #ifdef CONFIG_CGROUPS 930 /* disallow userland-initiated cgroup migration */ 931 unsigned no_cgroup_migration:1; 932 /* task is frozen/stopped (used by the cgroup freezer) */ 933 unsigned frozen:1; 934 #endif 935 #ifdef CONFIG_BLK_CGROUP 936 unsigned use_memdelay:1; 937 #endif 938 #ifdef CONFIG_PSI 939 /* Stalled due to lack of memory */ 940 unsigned in_memstall:1; 941 #endif 942 #ifdef CONFIG_PAGE_OWNER 943 /* Used by page_owner=on to detect recursion in page tracking. */ 944 unsigned in_page_owner:1; 945 #endif 946 #ifdef CONFIG_EVENTFD 947 /* Recursion prevention for eventfd_signal() */ 948 unsigned in_eventfd:1; 949 #endif 950 #ifdef CONFIG_IOMMU_SVA 951 unsigned pasid_activated:1; 952 #endif 953 #ifdef CONFIG_CPU_SUP_INTEL 954 unsigned reported_split_lock:1; 955 #endif 956 957 unsigned long atomic_flags; /* Flags requiring atomic access. */ 958 959 struct restart_block restart_block; 960 961 pid_t pid; 962 pid_t tgid; 963 964 #ifdef CONFIG_STACKPROTECTOR 965 /* Canary value for the -fstack-protector GCC feature: */ 966 unsigned long stack_canary; 967 #endif 968 /* 969 * Pointers to the (original) parent process, youngest child, younger sibling, 970 * older sibling, respectively. (p->father can be replaced with 971 * p->real_parent->pid) 972 */ 973 974 /* Real parent process: */ 975 struct task_struct __rcu *real_parent; 976 977 /* Recipient of SIGCHLD, wait4() reports: */ 978 struct task_struct __rcu *parent; 979 980 /* 981 * Children/sibling form the list of natural children: 982 */ 983 struct list_head children; 984 struct list_head sibling; 985 struct task_struct *group_leader; 986 987 /* 988 * 'ptraced' is the list of tasks this task is using ptrace() on. 989 * 990 * This includes both natural children and PTRACE_ATTACH targets. 991 * 'ptrace_entry' is this task's link on the p->parent->ptraced list. 992 */ 993 struct list_head ptraced; 994 struct list_head ptrace_entry; 995 996 /* PID/PID hash table linkage. */ 997 struct pid *thread_pid; 998 struct hlist_node pid_links[PIDTYPE_MAX]; 999 struct list_head thread_group; 1000 struct list_head thread_node; 1001 1002 struct completion *vfork_done; 1003 1004 /* CLONE_CHILD_SETTID: */ 1005 int __user *set_child_tid; 1006 1007 /* CLONE_CHILD_CLEARTID: */ 1008 int __user *clear_child_tid; 1009 1010 /* PF_KTHREAD | PF_IO_WORKER */ 1011 void *worker_private; 1012 1013 u64 utime; 1014 u64 stime; 1015 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME 1016 u64 utimescaled; 1017 u64 stimescaled; 1018 #endif 1019 u64 gtime; 1020 struct prev_cputime prev_cputime; 1021 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN 1022 struct vtime vtime; 1023 #endif 1024 1025 #ifdef CONFIG_NO_HZ_FULL 1026 atomic_t tick_dep_mask; 1027 #endif 1028 /* Context switch counts: */ 1029 unsigned long nvcsw; 1030 unsigned long nivcsw; 1031 1032 /* Monotonic time in nsecs: */ 1033 u64 start_time; 1034 1035 /* Boot based time in nsecs: */ 1036 u64 start_boottime; 1037 1038 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */ 1039 unsigned long min_flt; 1040 unsigned long maj_flt; 1041 1042 /* Empty if CONFIG_POSIX_CPUTIMERS=n */ 1043 struct posix_cputimers posix_cputimers; 1044 1045 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK 1046 struct posix_cputimers_work posix_cputimers_work; 1047 #endif 1048 1049 /* Process credentials: */ 1050 1051 /* Tracer's credentials at attach: */ 1052 const struct cred __rcu *ptracer_cred; 1053 1054 /* Objective and real subjective task credentials (COW): */ 1055 const struct cred __rcu *real_cred; 1056 1057 /* Effective (overridable) subjective task credentials (COW): */ 1058 const struct cred __rcu *cred; 1059 1060 #ifdef CONFIG_KEYS 1061 /* Cached requested key. */ 1062 struct key *cached_requested_key; 1063 #endif 1064 1065 /* 1066 * executable name, excluding path. 1067 * 1068 * - normally initialized setup_new_exec() 1069 * - access it with [gs]et_task_comm() 1070 * - lock it with task_lock() 1071 */ 1072 char comm[TASK_COMM_LEN]; 1073 1074 struct nameidata *nameidata; 1075 1076 #ifdef CONFIG_SYSVIPC 1077 struct sysv_sem sysvsem; 1078 struct sysv_shm sysvshm; 1079 #endif 1080 #ifdef CONFIG_DETECT_HUNG_TASK 1081 unsigned long last_switch_count; 1082 unsigned long last_switch_time; 1083 #endif 1084 /* Filesystem information: */ 1085 struct fs_struct *fs; 1086 1087 /* Open file information: */ 1088 struct files_struct *files; 1089 1090 #ifdef CONFIG_IO_URING 1091 struct io_uring_task *io_uring; 1092 #endif 1093 1094 /* Namespaces: */ 1095 struct nsproxy *nsproxy; 1096 1097 /* Signal handlers: */ 1098 struct signal_struct *signal; 1099 struct sighand_struct __rcu *sighand; 1100 sigset_t blocked; 1101 sigset_t real_blocked; 1102 /* Restored if set_restore_sigmask() was used: */ 1103 sigset_t saved_sigmask; 1104 struct sigpending pending; 1105 unsigned long sas_ss_sp; 1106 size_t sas_ss_size; 1107 unsigned int sas_ss_flags; 1108 1109 struct callback_head *task_works; 1110 1111 #ifdef CONFIG_AUDIT 1112 #ifdef CONFIG_AUDITSYSCALL 1113 struct audit_context *audit_context; 1114 #endif 1115 kuid_t loginuid; 1116 unsigned int sessionid; 1117 #endif 1118 struct seccomp seccomp; 1119 struct syscall_user_dispatch syscall_dispatch; 1120 1121 /* Thread group tracking: */ 1122 u64 parent_exec_id; 1123 u64 self_exec_id; 1124 1125 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */ 1126 spinlock_t alloc_lock; 1127 1128 /* Protection of the PI data structures: */ 1129 raw_spinlock_t pi_lock; 1130 1131 struct wake_q_node wake_q; 1132 1133 #ifdef CONFIG_RT_MUTEXES 1134 /* PI waiters blocked on a rt_mutex held by this task: */ 1135 struct rb_root_cached pi_waiters; 1136 /* Updated under owner's pi_lock and rq lock */ 1137 struct task_struct *pi_top_task; 1138 /* Deadlock detection and priority inheritance handling: */ 1139 struct rt_mutex_waiter *pi_blocked_on; 1140 #endif 1141 1142 #ifdef CONFIG_DEBUG_MUTEXES 1143 /* Mutex deadlock detection: */ 1144 struct mutex_waiter *blocked_on; 1145 #endif 1146 1147 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1148 int non_block_count; 1149 #endif 1150 1151 #ifdef CONFIG_TRACE_IRQFLAGS 1152 struct irqtrace_events irqtrace; 1153 unsigned int hardirq_threaded; 1154 u64 hardirq_chain_key; 1155 int softirqs_enabled; 1156 int softirq_context; 1157 int irq_config; 1158 #endif 1159 #ifdef CONFIG_PREEMPT_RT 1160 int softirq_disable_cnt; 1161 #endif 1162 1163 #ifdef CONFIG_LOCKDEP 1164 # define MAX_LOCK_DEPTH 48UL 1165 u64 curr_chain_key; 1166 int lockdep_depth; 1167 unsigned int lockdep_recursion; 1168 struct held_lock held_locks[MAX_LOCK_DEPTH]; 1169 #endif 1170 1171 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP) 1172 unsigned int in_ubsan; 1173 #endif 1174 1175 /* Journalling filesystem info: */ 1176 void *journal_info; 1177 1178 /* Stacked block device info: */ 1179 struct bio_list *bio_list; 1180 1181 /* Stack plugging: */ 1182 struct blk_plug *plug; 1183 1184 /* VM state: */ 1185 struct reclaim_state *reclaim_state; 1186 1187 struct backing_dev_info *backing_dev_info; 1188 1189 struct io_context *io_context; 1190 1191 #ifdef CONFIG_COMPACTION 1192 struct capture_control *capture_control; 1193 #endif 1194 /* Ptrace state: */ 1195 unsigned long ptrace_message; 1196 kernel_siginfo_t *last_siginfo; 1197 1198 struct task_io_accounting ioac; 1199 #ifdef CONFIG_PSI 1200 /* Pressure stall state */ 1201 unsigned int psi_flags; 1202 #endif 1203 #ifdef CONFIG_TASK_XACCT 1204 /* Accumulated RSS usage: */ 1205 u64 acct_rss_mem1; 1206 /* Accumulated virtual memory usage: */ 1207 u64 acct_vm_mem1; 1208 /* stime + utime since last update: */ 1209 u64 acct_timexpd; 1210 #endif 1211 #ifdef CONFIG_CPUSETS 1212 /* Protected by ->alloc_lock: */ 1213 nodemask_t mems_allowed; 1214 /* Sequence number to catch updates: */ 1215 seqcount_spinlock_t mems_allowed_seq; 1216 int cpuset_mem_spread_rotor; 1217 int cpuset_slab_spread_rotor; 1218 #endif 1219 #ifdef CONFIG_CGROUPS 1220 /* Control Group info protected by css_set_lock: */ 1221 struct css_set __rcu *cgroups; 1222 /* cg_list protected by css_set_lock and tsk->alloc_lock: */ 1223 struct list_head cg_list; 1224 #endif 1225 #ifdef CONFIG_X86_CPU_RESCTRL 1226 u32 closid; 1227 u32 rmid; 1228 #endif 1229 #ifdef CONFIG_FUTEX 1230 struct robust_list_head __user *robust_list; 1231 #ifdef CONFIG_COMPAT 1232 struct compat_robust_list_head __user *compat_robust_list; 1233 #endif 1234 struct list_head pi_state_list; 1235 struct futex_pi_state *pi_state_cache; 1236 struct mutex futex_exit_mutex; 1237 unsigned int futex_state; 1238 #endif 1239 #ifdef CONFIG_PERF_EVENTS 1240 struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts]; 1241 struct mutex perf_event_mutex; 1242 struct list_head perf_event_list; 1243 #endif 1244 #ifdef CONFIG_DEBUG_PREEMPT 1245 unsigned long preempt_disable_ip; 1246 #endif 1247 #ifdef CONFIG_NUMA 1248 /* Protected by alloc_lock: */ 1249 struct mempolicy *mempolicy; 1250 short il_prev; 1251 short pref_node_fork; 1252 #endif 1253 #ifdef CONFIG_NUMA_BALANCING 1254 int numa_scan_seq; 1255 unsigned int numa_scan_period; 1256 unsigned int numa_scan_period_max; 1257 int numa_preferred_nid; 1258 unsigned long numa_migrate_retry; 1259 /* Migration stamp: */ 1260 u64 node_stamp; 1261 u64 last_task_numa_placement; 1262 u64 last_sum_exec_runtime; 1263 struct callback_head numa_work; 1264 1265 /* 1266 * This pointer is only modified for current in syscall and 1267 * pagefault context (and for tasks being destroyed), so it can be read 1268 * from any of the following contexts: 1269 * - RCU read-side critical section 1270 * - current->numa_group from everywhere 1271 * - task's runqueue locked, task not running 1272 */ 1273 struct numa_group __rcu *numa_group; 1274 1275 /* 1276 * numa_faults is an array split into four regions: 1277 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer 1278 * in this precise order. 1279 * 1280 * faults_memory: Exponential decaying average of faults on a per-node 1281 * basis. Scheduling placement decisions are made based on these 1282 * counts. The values remain static for the duration of a PTE scan. 1283 * faults_cpu: Track the nodes the process was running on when a NUMA 1284 * hinting fault was incurred. 1285 * faults_memory_buffer and faults_cpu_buffer: Record faults per node 1286 * during the current scan window. When the scan completes, the counts 1287 * in faults_memory and faults_cpu decay and these values are copied. 1288 */ 1289 unsigned long *numa_faults; 1290 unsigned long total_numa_faults; 1291 1292 /* 1293 * numa_faults_locality tracks if faults recorded during the last 1294 * scan window were remote/local or failed to migrate. The task scan 1295 * period is adapted based on the locality of the faults with different 1296 * weights depending on whether they were shared or private faults 1297 */ 1298 unsigned long numa_faults_locality[3]; 1299 1300 unsigned long numa_pages_migrated; 1301 #endif /* CONFIG_NUMA_BALANCING */ 1302 1303 #ifdef CONFIG_RSEQ 1304 struct rseq __user *rseq; 1305 u32 rseq_sig; 1306 /* 1307 * RmW on rseq_event_mask must be performed atomically 1308 * with respect to preemption. 1309 */ 1310 unsigned long rseq_event_mask; 1311 #endif 1312 1313 struct tlbflush_unmap_batch tlb_ubc; 1314 1315 union { 1316 refcount_t rcu_users; 1317 struct rcu_head rcu; 1318 }; 1319 1320 /* Cache last used pipe for splice(): */ 1321 struct pipe_inode_info *splice_pipe; 1322 1323 struct page_frag task_frag; 1324 1325 #ifdef CONFIG_TASK_DELAY_ACCT 1326 struct task_delay_info *delays; 1327 #endif 1328 1329 #ifdef CONFIG_FAULT_INJECTION 1330 int make_it_fail; 1331 unsigned int fail_nth; 1332 #endif 1333 /* 1334 * When (nr_dirtied >= nr_dirtied_pause), it's time to call 1335 * balance_dirty_pages() for a dirty throttling pause: 1336 */ 1337 int nr_dirtied; 1338 int nr_dirtied_pause; 1339 /* Start of a write-and-pause period: */ 1340 unsigned long dirty_paused_when; 1341 1342 #ifdef CONFIG_LATENCYTOP 1343 int latency_record_count; 1344 struct latency_record latency_record[LT_SAVECOUNT]; 1345 #endif 1346 /* 1347 * Time slack values; these are used to round up poll() and 1348 * select() etc timeout values. These are in nanoseconds. 1349 */ 1350 u64 timer_slack_ns; 1351 u64 default_timer_slack_ns; 1352 1353 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) 1354 unsigned int kasan_depth; 1355 #endif 1356 1357 #ifdef CONFIG_KCSAN 1358 struct kcsan_ctx kcsan_ctx; 1359 #ifdef CONFIG_TRACE_IRQFLAGS 1360 struct irqtrace_events kcsan_save_irqtrace; 1361 #endif 1362 #ifdef CONFIG_KCSAN_WEAK_MEMORY 1363 int kcsan_stack_depth; 1364 #endif 1365 #endif 1366 1367 #if IS_ENABLED(CONFIG_KUNIT) 1368 struct kunit *kunit_test; 1369 #endif 1370 1371 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 1372 /* Index of current stored address in ret_stack: */ 1373 int curr_ret_stack; 1374 int curr_ret_depth; 1375 1376 /* Stack of return addresses for return function tracing: */ 1377 struct ftrace_ret_stack *ret_stack; 1378 1379 /* Timestamp for last schedule: */ 1380 unsigned long long ftrace_timestamp; 1381 1382 /* 1383 * Number of functions that haven't been traced 1384 * because of depth overrun: 1385 */ 1386 atomic_t trace_overrun; 1387 1388 /* Pause tracing: */ 1389 atomic_t tracing_graph_pause; 1390 #endif 1391 1392 #ifdef CONFIG_TRACING 1393 /* Bitmask and counter of trace recursion: */ 1394 unsigned long trace_recursion; 1395 #endif /* CONFIG_TRACING */ 1396 1397 #ifdef CONFIG_KCOV 1398 /* See kernel/kcov.c for more details. */ 1399 1400 /* Coverage collection mode enabled for this task (0 if disabled): */ 1401 unsigned int kcov_mode; 1402 1403 /* Size of the kcov_area: */ 1404 unsigned int kcov_size; 1405 1406 /* Buffer for coverage collection: */ 1407 void *kcov_area; 1408 1409 /* KCOV descriptor wired with this task or NULL: */ 1410 struct kcov *kcov; 1411 1412 /* KCOV common handle for remote coverage collection: */ 1413 u64 kcov_handle; 1414 1415 /* KCOV sequence number: */ 1416 int kcov_sequence; 1417 1418 /* Collect coverage from softirq context: */ 1419 unsigned int kcov_softirq; 1420 #endif 1421 1422 #ifdef CONFIG_MEMCG 1423 struct mem_cgroup *memcg_in_oom; 1424 gfp_t memcg_oom_gfp_mask; 1425 int memcg_oom_order; 1426 1427 /* Number of pages to reclaim on returning to userland: */ 1428 unsigned int memcg_nr_pages_over_high; 1429 1430 /* Used by memcontrol for targeted memcg charge: */ 1431 struct mem_cgroup *active_memcg; 1432 #endif 1433 1434 #ifdef CONFIG_BLK_CGROUP 1435 struct request_queue *throttle_queue; 1436 #endif 1437 1438 #ifdef CONFIG_UPROBES 1439 struct uprobe_task *utask; 1440 #endif 1441 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE) 1442 unsigned int sequential_io; 1443 unsigned int sequential_io_avg; 1444 #endif 1445 struct kmap_ctrl kmap_ctrl; 1446 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1447 unsigned long task_state_change; 1448 # ifdef CONFIG_PREEMPT_RT 1449 unsigned long saved_state_change; 1450 # endif 1451 #endif 1452 int pagefault_disabled; 1453 #ifdef CONFIG_MMU 1454 struct task_struct *oom_reaper_list; 1455 struct timer_list oom_reaper_timer; 1456 #endif 1457 #ifdef CONFIG_VMAP_STACK 1458 struct vm_struct *stack_vm_area; 1459 #endif 1460 #ifdef CONFIG_THREAD_INFO_IN_TASK 1461 /* A live task holds one reference: */ 1462 refcount_t stack_refcount; 1463 #endif 1464 #ifdef CONFIG_LIVEPATCH 1465 int patch_state; 1466 #endif 1467 #ifdef CONFIG_SECURITY 1468 /* Used by LSM modules for access restriction: */ 1469 void *security; 1470 #endif 1471 #ifdef CONFIG_BPF_SYSCALL 1472 /* Used by BPF task local storage */ 1473 struct bpf_local_storage __rcu *bpf_storage; 1474 /* Used for BPF run context */ 1475 struct bpf_run_ctx *bpf_ctx; 1476 #endif 1477 1478 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK 1479 unsigned long lowest_stack; 1480 unsigned long prev_lowest_stack; 1481 #endif 1482 1483 #ifdef CONFIG_X86_MCE 1484 void __user *mce_vaddr; 1485 __u64 mce_kflags; 1486 u64 mce_addr; 1487 __u64 mce_ripv : 1, 1488 mce_whole_page : 1, 1489 __mce_reserved : 62; 1490 struct callback_head mce_kill_me; 1491 int mce_count; 1492 #endif 1493 1494 #ifdef CONFIG_KRETPROBES 1495 struct llist_head kretprobe_instances; 1496 #endif 1497 #ifdef CONFIG_RETHOOK 1498 struct llist_head rethooks; 1499 #endif 1500 1501 #ifdef CONFIG_ARCH_HAS_PARANOID_L1D_FLUSH 1502 /* 1503 * If L1D flush is supported on mm context switch 1504 * then we use this callback head to queue kill work 1505 * to kill tasks that are not running on SMT disabled 1506 * cores 1507 */ 1508 struct callback_head l1d_flush_kill; 1509 #endif 1510 1511 #ifdef CONFIG_RV 1512 /* 1513 * Per-task RV monitor. Nowadays fixed in RV_PER_TASK_MONITORS. 1514 * If we find justification for more monitors, we can think 1515 * about adding more or developing a dynamic method. So far, 1516 * none of these are justified. 1517 */ 1518 union rv_task_monitor rv[RV_PER_TASK_MONITORS]; 1519 #endif 1520 1521 /* 1522 * New fields for task_struct should be added above here, so that 1523 * they are included in the randomized portion of task_struct. 1524 */ 1525 randomized_struct_fields_end 1526 1527 /* CPU-specific state of this task: */ 1528 struct thread_struct thread; 1529 1530 /* 1531 * WARNING: on x86, 'thread_struct' contains a variable-sized 1532 * structure. It *MUST* be at the end of 'task_struct'. 1533 * 1534 * Do not put anything below here! 1535 */ 1536 }; 1537 1538 static inline struct pid *task_pid(struct task_struct *task) 1539 { 1540 return task->thread_pid; 1541 } 1542 1543 /* 1544 * the helpers to get the task's different pids as they are seen 1545 * from various namespaces 1546 * 1547 * task_xid_nr() : global id, i.e. the id seen from the init namespace; 1548 * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of 1549 * current. 1550 * task_xid_nr_ns() : id seen from the ns specified; 1551 * 1552 * see also pid_nr() etc in include/linux/pid.h 1553 */ 1554 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns); 1555 1556 static inline pid_t task_pid_nr(struct task_struct *tsk) 1557 { 1558 return tsk->pid; 1559 } 1560 1561 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1562 { 1563 return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns); 1564 } 1565 1566 static inline pid_t task_pid_vnr(struct task_struct *tsk) 1567 { 1568 return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL); 1569 } 1570 1571 1572 static inline pid_t task_tgid_nr(struct task_struct *tsk) 1573 { 1574 return tsk->tgid; 1575 } 1576 1577 /** 1578 * pid_alive - check that a task structure is not stale 1579 * @p: Task structure to be checked. 1580 * 1581 * Test if a process is not yet dead (at most zombie state) 1582 * If pid_alive fails, then pointers within the task structure 1583 * can be stale and must not be dereferenced. 1584 * 1585 * Return: 1 if the process is alive. 0 otherwise. 1586 */ 1587 static inline int pid_alive(const struct task_struct *p) 1588 { 1589 return p->thread_pid != NULL; 1590 } 1591 1592 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1593 { 1594 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns); 1595 } 1596 1597 static inline pid_t task_pgrp_vnr(struct task_struct *tsk) 1598 { 1599 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL); 1600 } 1601 1602 1603 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1604 { 1605 return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns); 1606 } 1607 1608 static inline pid_t task_session_vnr(struct task_struct *tsk) 1609 { 1610 return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL); 1611 } 1612 1613 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1614 { 1615 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, ns); 1616 } 1617 1618 static inline pid_t task_tgid_vnr(struct task_struct *tsk) 1619 { 1620 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, NULL); 1621 } 1622 1623 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns) 1624 { 1625 pid_t pid = 0; 1626 1627 rcu_read_lock(); 1628 if (pid_alive(tsk)) 1629 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns); 1630 rcu_read_unlock(); 1631 1632 return pid; 1633 } 1634 1635 static inline pid_t task_ppid_nr(const struct task_struct *tsk) 1636 { 1637 return task_ppid_nr_ns(tsk, &init_pid_ns); 1638 } 1639 1640 /* Obsolete, do not use: */ 1641 static inline pid_t task_pgrp_nr(struct task_struct *tsk) 1642 { 1643 return task_pgrp_nr_ns(tsk, &init_pid_ns); 1644 } 1645 1646 #define TASK_REPORT_IDLE (TASK_REPORT + 1) 1647 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1) 1648 1649 static inline unsigned int __task_state_index(unsigned int tsk_state, 1650 unsigned int tsk_exit_state) 1651 { 1652 unsigned int state = (tsk_state | tsk_exit_state) & TASK_REPORT; 1653 1654 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX); 1655 1656 if (tsk_state == TASK_IDLE) 1657 state = TASK_REPORT_IDLE; 1658 1659 /* 1660 * We're lying here, but rather than expose a completely new task state 1661 * to userspace, we can make this appear as if the task has gone through 1662 * a regular rt_mutex_lock() call. 1663 */ 1664 if (tsk_state == TASK_RTLOCK_WAIT) 1665 state = TASK_UNINTERRUPTIBLE; 1666 1667 return fls(state); 1668 } 1669 1670 static inline unsigned int task_state_index(struct task_struct *tsk) 1671 { 1672 return __task_state_index(READ_ONCE(tsk->__state), tsk->exit_state); 1673 } 1674 1675 static inline char task_index_to_char(unsigned int state) 1676 { 1677 static const char state_char[] = "RSDTtXZPI"; 1678 1679 BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1); 1680 1681 return state_char[state]; 1682 } 1683 1684 static inline char task_state_to_char(struct task_struct *tsk) 1685 { 1686 return task_index_to_char(task_state_index(tsk)); 1687 } 1688 1689 /** 1690 * is_global_init - check if a task structure is init. Since init 1691 * is free to have sub-threads we need to check tgid. 1692 * @tsk: Task structure to be checked. 1693 * 1694 * Check if a task structure is the first user space task the kernel created. 1695 * 1696 * Return: 1 if the task structure is init. 0 otherwise. 1697 */ 1698 static inline int is_global_init(struct task_struct *tsk) 1699 { 1700 return task_tgid_nr(tsk) == 1; 1701 } 1702 1703 extern struct pid *cad_pid; 1704 1705 /* 1706 * Per process flags 1707 */ 1708 #define PF_VCPU 0x00000001 /* I'm a virtual CPU */ 1709 #define PF_IDLE 0x00000002 /* I am an IDLE thread */ 1710 #define PF_EXITING 0x00000004 /* Getting shut down */ 1711 #define PF_POSTCOREDUMP 0x00000008 /* Coredumps should ignore this task */ 1712 #define PF_IO_WORKER 0x00000010 /* Task is an IO worker */ 1713 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */ 1714 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */ 1715 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */ 1716 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */ 1717 #define PF_DUMPCORE 0x00000200 /* Dumped core */ 1718 #define PF_SIGNALED 0x00000400 /* Killed by a signal */ 1719 #define PF_MEMALLOC 0x00000800 /* Allocating memory */ 1720 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */ 1721 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */ 1722 #define PF__HOLE__00004000 0x00004000 1723 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */ 1724 #define PF__HOLE__00010000 0x00010000 1725 #define PF_KSWAPD 0x00020000 /* I am kswapd */ 1726 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocation requests will inherit GFP_NOFS */ 1727 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocation requests will inherit GFP_NOIO */ 1728 #define PF_LOCAL_THROTTLE 0x00100000 /* Throttle writes only against the bdi I write to, 1729 * I am cleaning dirty pages from some other bdi. */ 1730 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */ 1731 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */ 1732 #define PF__HOLE__00800000 0x00800000 1733 #define PF__HOLE__01000000 0x01000000 1734 #define PF__HOLE__02000000 0x02000000 1735 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */ 1736 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */ 1737 #define PF_MEMALLOC_PIN 0x10000000 /* Allocation context constrained to zones which allow long term pinning. */ 1738 #define PF__HOLE__20000000 0x20000000 1739 #define PF__HOLE__40000000 0x40000000 1740 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */ 1741 1742 /* 1743 * Only the _current_ task can read/write to tsk->flags, but other 1744 * tasks can access tsk->flags in readonly mode for example 1745 * with tsk_used_math (like during threaded core dumping). 1746 * There is however an exception to this rule during ptrace 1747 * or during fork: the ptracer task is allowed to write to the 1748 * child->flags of its traced child (same goes for fork, the parent 1749 * can write to the child->flags), because we're guaranteed the 1750 * child is not running and in turn not changing child->flags 1751 * at the same time the parent does it. 1752 */ 1753 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0) 1754 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0) 1755 #define clear_used_math() clear_stopped_child_used_math(current) 1756 #define set_used_math() set_stopped_child_used_math(current) 1757 1758 #define conditional_stopped_child_used_math(condition, child) \ 1759 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0) 1760 1761 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current) 1762 1763 #define copy_to_stopped_child_used_math(child) \ 1764 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0) 1765 1766 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */ 1767 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH) 1768 #define used_math() tsk_used_math(current) 1769 1770 static __always_inline bool is_percpu_thread(void) 1771 { 1772 #ifdef CONFIG_SMP 1773 return (current->flags & PF_NO_SETAFFINITY) && 1774 (current->nr_cpus_allowed == 1); 1775 #else 1776 return true; 1777 #endif 1778 } 1779 1780 /* Per-process atomic flags. */ 1781 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */ 1782 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */ 1783 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */ 1784 #define PFA_SPEC_SSB_DISABLE 3 /* Speculative Store Bypass disabled */ 1785 #define PFA_SPEC_SSB_FORCE_DISABLE 4 /* Speculative Store Bypass force disabled*/ 1786 #define PFA_SPEC_IB_DISABLE 5 /* Indirect branch speculation restricted */ 1787 #define PFA_SPEC_IB_FORCE_DISABLE 6 /* Indirect branch speculation permanently restricted */ 1788 #define PFA_SPEC_SSB_NOEXEC 7 /* Speculative Store Bypass clear on execve() */ 1789 1790 #define TASK_PFA_TEST(name, func) \ 1791 static inline bool task_##func(struct task_struct *p) \ 1792 { return test_bit(PFA_##name, &p->atomic_flags); } 1793 1794 #define TASK_PFA_SET(name, func) \ 1795 static inline void task_set_##func(struct task_struct *p) \ 1796 { set_bit(PFA_##name, &p->atomic_flags); } 1797 1798 #define TASK_PFA_CLEAR(name, func) \ 1799 static inline void task_clear_##func(struct task_struct *p) \ 1800 { clear_bit(PFA_##name, &p->atomic_flags); } 1801 1802 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs) 1803 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs) 1804 1805 TASK_PFA_TEST(SPREAD_PAGE, spread_page) 1806 TASK_PFA_SET(SPREAD_PAGE, spread_page) 1807 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page) 1808 1809 TASK_PFA_TEST(SPREAD_SLAB, spread_slab) 1810 TASK_PFA_SET(SPREAD_SLAB, spread_slab) 1811 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab) 1812 1813 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable) 1814 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable) 1815 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable) 1816 1817 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1818 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1819 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1820 1821 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1822 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1823 1824 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable) 1825 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable) 1826 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable) 1827 1828 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1829 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1830 1831 static inline void 1832 current_restore_flags(unsigned long orig_flags, unsigned long flags) 1833 { 1834 current->flags &= ~flags; 1835 current->flags |= orig_flags & flags; 1836 } 1837 1838 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial); 1839 extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_effective_cpus); 1840 #ifdef CONFIG_SMP 1841 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask); 1842 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask); 1843 extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node); 1844 extern void release_user_cpus_ptr(struct task_struct *p); 1845 extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask); 1846 extern void force_compatible_cpus_allowed_ptr(struct task_struct *p); 1847 extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p); 1848 #else 1849 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) 1850 { 1851 } 1852 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) 1853 { 1854 if (!cpumask_test_cpu(0, new_mask)) 1855 return -EINVAL; 1856 return 0; 1857 } 1858 static inline int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node) 1859 { 1860 if (src->user_cpus_ptr) 1861 return -EINVAL; 1862 return 0; 1863 } 1864 static inline void release_user_cpus_ptr(struct task_struct *p) 1865 { 1866 WARN_ON(p->user_cpus_ptr); 1867 } 1868 1869 static inline int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask) 1870 { 1871 return 0; 1872 } 1873 #endif 1874 1875 extern int yield_to(struct task_struct *p, bool preempt); 1876 extern void set_user_nice(struct task_struct *p, long nice); 1877 extern int task_prio(const struct task_struct *p); 1878 1879 /** 1880 * task_nice - return the nice value of a given task. 1881 * @p: the task in question. 1882 * 1883 * Return: The nice value [ -20 ... 0 ... 19 ]. 1884 */ 1885 static inline int task_nice(const struct task_struct *p) 1886 { 1887 return PRIO_TO_NICE((p)->static_prio); 1888 } 1889 1890 extern int can_nice(const struct task_struct *p, const int nice); 1891 extern int task_curr(const struct task_struct *p); 1892 extern int idle_cpu(int cpu); 1893 extern int available_idle_cpu(int cpu); 1894 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *); 1895 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *); 1896 extern void sched_set_fifo(struct task_struct *p); 1897 extern void sched_set_fifo_low(struct task_struct *p); 1898 extern void sched_set_normal(struct task_struct *p, int nice); 1899 extern int sched_setattr(struct task_struct *, const struct sched_attr *); 1900 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *); 1901 extern struct task_struct *idle_task(int cpu); 1902 1903 /** 1904 * is_idle_task - is the specified task an idle task? 1905 * @p: the task in question. 1906 * 1907 * Return: 1 if @p is an idle task. 0 otherwise. 1908 */ 1909 static __always_inline bool is_idle_task(const struct task_struct *p) 1910 { 1911 return !!(p->flags & PF_IDLE); 1912 } 1913 1914 extern struct task_struct *curr_task(int cpu); 1915 extern void ia64_set_curr_task(int cpu, struct task_struct *p); 1916 1917 void yield(void); 1918 1919 union thread_union { 1920 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK 1921 struct task_struct task; 1922 #endif 1923 #ifndef CONFIG_THREAD_INFO_IN_TASK 1924 struct thread_info thread_info; 1925 #endif 1926 unsigned long stack[THREAD_SIZE/sizeof(long)]; 1927 }; 1928 1929 #ifndef CONFIG_THREAD_INFO_IN_TASK 1930 extern struct thread_info init_thread_info; 1931 #endif 1932 1933 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)]; 1934 1935 #ifdef CONFIG_THREAD_INFO_IN_TASK 1936 # define task_thread_info(task) (&(task)->thread_info) 1937 #elif !defined(__HAVE_THREAD_FUNCTIONS) 1938 # define task_thread_info(task) ((struct thread_info *)(task)->stack) 1939 #endif 1940 1941 /* 1942 * find a task by one of its numerical ids 1943 * 1944 * find_task_by_pid_ns(): 1945 * finds a task by its pid in the specified namespace 1946 * find_task_by_vpid(): 1947 * finds a task by its virtual pid 1948 * 1949 * see also find_vpid() etc in include/linux/pid.h 1950 */ 1951 1952 extern struct task_struct *find_task_by_vpid(pid_t nr); 1953 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns); 1954 1955 /* 1956 * find a task by its virtual pid and get the task struct 1957 */ 1958 extern struct task_struct *find_get_task_by_vpid(pid_t nr); 1959 1960 extern int wake_up_state(struct task_struct *tsk, unsigned int state); 1961 extern int wake_up_process(struct task_struct *tsk); 1962 extern void wake_up_new_task(struct task_struct *tsk); 1963 1964 #ifdef CONFIG_SMP 1965 extern void kick_process(struct task_struct *tsk); 1966 #else 1967 static inline void kick_process(struct task_struct *tsk) { } 1968 #endif 1969 1970 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec); 1971 1972 static inline void set_task_comm(struct task_struct *tsk, const char *from) 1973 { 1974 __set_task_comm(tsk, from, false); 1975 } 1976 1977 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk); 1978 #define get_task_comm(buf, tsk) ({ \ 1979 BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN); \ 1980 __get_task_comm(buf, sizeof(buf), tsk); \ 1981 }) 1982 1983 #ifdef CONFIG_SMP 1984 static __always_inline void scheduler_ipi(void) 1985 { 1986 /* 1987 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting 1988 * TIF_NEED_RESCHED remotely (for the first time) will also send 1989 * this IPI. 1990 */ 1991 preempt_fold_need_resched(); 1992 } 1993 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state); 1994 #else 1995 static inline void scheduler_ipi(void) { } 1996 static inline unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state) 1997 { 1998 return 1; 1999 } 2000 #endif 2001 2002 /* 2003 * Set thread flags in other task's structures. 2004 * See asm/thread_info.h for TIF_xxxx flags available: 2005 */ 2006 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag) 2007 { 2008 set_ti_thread_flag(task_thread_info(tsk), flag); 2009 } 2010 2011 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag) 2012 { 2013 clear_ti_thread_flag(task_thread_info(tsk), flag); 2014 } 2015 2016 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag, 2017 bool value) 2018 { 2019 update_ti_thread_flag(task_thread_info(tsk), flag, value); 2020 } 2021 2022 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag) 2023 { 2024 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag); 2025 } 2026 2027 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag) 2028 { 2029 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag); 2030 } 2031 2032 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag) 2033 { 2034 return test_ti_thread_flag(task_thread_info(tsk), flag); 2035 } 2036 2037 static inline void set_tsk_need_resched(struct task_struct *tsk) 2038 { 2039 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 2040 } 2041 2042 static inline void clear_tsk_need_resched(struct task_struct *tsk) 2043 { 2044 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 2045 } 2046 2047 static inline int test_tsk_need_resched(struct task_struct *tsk) 2048 { 2049 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED)); 2050 } 2051 2052 /* 2053 * cond_resched() and cond_resched_lock(): latency reduction via 2054 * explicit rescheduling in places that are safe. The return 2055 * value indicates whether a reschedule was done in fact. 2056 * cond_resched_lock() will drop the spinlock before scheduling, 2057 */ 2058 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) 2059 extern int __cond_resched(void); 2060 2061 #if defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL) 2062 2063 DECLARE_STATIC_CALL(cond_resched, __cond_resched); 2064 2065 static __always_inline int _cond_resched(void) 2066 { 2067 return static_call_mod(cond_resched)(); 2068 } 2069 2070 #elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY) 2071 extern int dynamic_cond_resched(void); 2072 2073 static __always_inline int _cond_resched(void) 2074 { 2075 return dynamic_cond_resched(); 2076 } 2077 2078 #else 2079 2080 static inline int _cond_resched(void) 2081 { 2082 return __cond_resched(); 2083 } 2084 2085 #endif /* CONFIG_PREEMPT_DYNAMIC */ 2086 2087 #else 2088 2089 static inline int _cond_resched(void) { return 0; } 2090 2091 #endif /* !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) */ 2092 2093 #define cond_resched() ({ \ 2094 __might_resched(__FILE__, __LINE__, 0); \ 2095 _cond_resched(); \ 2096 }) 2097 2098 extern int __cond_resched_lock(spinlock_t *lock); 2099 extern int __cond_resched_rwlock_read(rwlock_t *lock); 2100 extern int __cond_resched_rwlock_write(rwlock_t *lock); 2101 2102 #define MIGHT_RESCHED_RCU_SHIFT 8 2103 #define MIGHT_RESCHED_PREEMPT_MASK ((1U << MIGHT_RESCHED_RCU_SHIFT) - 1) 2104 2105 #ifndef CONFIG_PREEMPT_RT 2106 /* 2107 * Non RT kernels have an elevated preempt count due to the held lock, 2108 * but are not allowed to be inside a RCU read side critical section 2109 */ 2110 # define PREEMPT_LOCK_RESCHED_OFFSETS PREEMPT_LOCK_OFFSET 2111 #else 2112 /* 2113 * spin/rw_lock() on RT implies rcu_read_lock(). The might_sleep() check in 2114 * cond_resched*lock() has to take that into account because it checks for 2115 * preempt_count() and rcu_preempt_depth(). 2116 */ 2117 # define PREEMPT_LOCK_RESCHED_OFFSETS \ 2118 (PREEMPT_LOCK_OFFSET + (1U << MIGHT_RESCHED_RCU_SHIFT)) 2119 #endif 2120 2121 #define cond_resched_lock(lock) ({ \ 2122 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2123 __cond_resched_lock(lock); \ 2124 }) 2125 2126 #define cond_resched_rwlock_read(lock) ({ \ 2127 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2128 __cond_resched_rwlock_read(lock); \ 2129 }) 2130 2131 #define cond_resched_rwlock_write(lock) ({ \ 2132 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2133 __cond_resched_rwlock_write(lock); \ 2134 }) 2135 2136 static inline void cond_resched_rcu(void) 2137 { 2138 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU) 2139 rcu_read_unlock(); 2140 cond_resched(); 2141 rcu_read_lock(); 2142 #endif 2143 } 2144 2145 #ifdef CONFIG_PREEMPT_DYNAMIC 2146 2147 extern bool preempt_model_none(void); 2148 extern bool preempt_model_voluntary(void); 2149 extern bool preempt_model_full(void); 2150 2151 #else 2152 2153 static inline bool preempt_model_none(void) 2154 { 2155 return IS_ENABLED(CONFIG_PREEMPT_NONE); 2156 } 2157 static inline bool preempt_model_voluntary(void) 2158 { 2159 return IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY); 2160 } 2161 static inline bool preempt_model_full(void) 2162 { 2163 return IS_ENABLED(CONFIG_PREEMPT); 2164 } 2165 2166 #endif 2167 2168 static inline bool preempt_model_rt(void) 2169 { 2170 return IS_ENABLED(CONFIG_PREEMPT_RT); 2171 } 2172 2173 /* 2174 * Does the preemption model allow non-cooperative preemption? 2175 * 2176 * For !CONFIG_PREEMPT_DYNAMIC kernels this is an exact match with 2177 * CONFIG_PREEMPTION; for CONFIG_PREEMPT_DYNAMIC this doesn't work as the 2178 * kernel is *built* with CONFIG_PREEMPTION=y but may run with e.g. the 2179 * PREEMPT_NONE model. 2180 */ 2181 static inline bool preempt_model_preemptible(void) 2182 { 2183 return preempt_model_full() || preempt_model_rt(); 2184 } 2185 2186 /* 2187 * Does a critical section need to be broken due to another 2188 * task waiting?: (technically does not depend on CONFIG_PREEMPTION, 2189 * but a general need for low latency) 2190 */ 2191 static inline int spin_needbreak(spinlock_t *lock) 2192 { 2193 #ifdef CONFIG_PREEMPTION 2194 return spin_is_contended(lock); 2195 #else 2196 return 0; 2197 #endif 2198 } 2199 2200 /* 2201 * Check if a rwlock is contended. 2202 * Returns non-zero if there is another task waiting on the rwlock. 2203 * Returns zero if the lock is not contended or the system / underlying 2204 * rwlock implementation does not support contention detection. 2205 * Technically does not depend on CONFIG_PREEMPTION, but a general need 2206 * for low latency. 2207 */ 2208 static inline int rwlock_needbreak(rwlock_t *lock) 2209 { 2210 #ifdef CONFIG_PREEMPTION 2211 return rwlock_is_contended(lock); 2212 #else 2213 return 0; 2214 #endif 2215 } 2216 2217 static __always_inline bool need_resched(void) 2218 { 2219 return unlikely(tif_need_resched()); 2220 } 2221 2222 /* 2223 * Wrappers for p->thread_info->cpu access. No-op on UP. 2224 */ 2225 #ifdef CONFIG_SMP 2226 2227 static inline unsigned int task_cpu(const struct task_struct *p) 2228 { 2229 return READ_ONCE(task_thread_info(p)->cpu); 2230 } 2231 2232 extern void set_task_cpu(struct task_struct *p, unsigned int cpu); 2233 2234 #else 2235 2236 static inline unsigned int task_cpu(const struct task_struct *p) 2237 { 2238 return 0; 2239 } 2240 2241 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu) 2242 { 2243 } 2244 2245 #endif /* CONFIG_SMP */ 2246 2247 extern bool sched_task_on_rq(struct task_struct *p); 2248 extern unsigned long get_wchan(struct task_struct *p); 2249 extern struct task_struct *cpu_curr_snapshot(int cpu); 2250 2251 /* 2252 * In order to reduce various lock holder preemption latencies provide an 2253 * interface to see if a vCPU is currently running or not. 2254 * 2255 * This allows us to terminate optimistic spin loops and block, analogous to 2256 * the native optimistic spin heuristic of testing if the lock owner task is 2257 * running or not. 2258 */ 2259 #ifndef vcpu_is_preempted 2260 static inline bool vcpu_is_preempted(int cpu) 2261 { 2262 return false; 2263 } 2264 #endif 2265 2266 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask); 2267 extern long sched_getaffinity(pid_t pid, struct cpumask *mask); 2268 2269 #ifndef TASK_SIZE_OF 2270 #define TASK_SIZE_OF(tsk) TASK_SIZE 2271 #endif 2272 2273 #ifdef CONFIG_SMP 2274 static inline bool owner_on_cpu(struct task_struct *owner) 2275 { 2276 /* 2277 * As lock holder preemption issue, we both skip spinning if 2278 * task is not on cpu or its cpu is preempted 2279 */ 2280 return READ_ONCE(owner->on_cpu) && !vcpu_is_preempted(task_cpu(owner)); 2281 } 2282 2283 /* Returns effective CPU energy utilization, as seen by the scheduler */ 2284 unsigned long sched_cpu_util(int cpu); 2285 #endif /* CONFIG_SMP */ 2286 2287 #ifdef CONFIG_RSEQ 2288 2289 /* 2290 * Map the event mask on the user-space ABI enum rseq_cs_flags 2291 * for direct mask checks. 2292 */ 2293 enum rseq_event_mask_bits { 2294 RSEQ_EVENT_PREEMPT_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT, 2295 RSEQ_EVENT_SIGNAL_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT, 2296 RSEQ_EVENT_MIGRATE_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT, 2297 }; 2298 2299 enum rseq_event_mask { 2300 RSEQ_EVENT_PREEMPT = (1U << RSEQ_EVENT_PREEMPT_BIT), 2301 RSEQ_EVENT_SIGNAL = (1U << RSEQ_EVENT_SIGNAL_BIT), 2302 RSEQ_EVENT_MIGRATE = (1U << RSEQ_EVENT_MIGRATE_BIT), 2303 }; 2304 2305 static inline void rseq_set_notify_resume(struct task_struct *t) 2306 { 2307 if (t->rseq) 2308 set_tsk_thread_flag(t, TIF_NOTIFY_RESUME); 2309 } 2310 2311 void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs); 2312 2313 static inline void rseq_handle_notify_resume(struct ksignal *ksig, 2314 struct pt_regs *regs) 2315 { 2316 if (current->rseq) 2317 __rseq_handle_notify_resume(ksig, regs); 2318 } 2319 2320 static inline void rseq_signal_deliver(struct ksignal *ksig, 2321 struct pt_regs *regs) 2322 { 2323 preempt_disable(); 2324 __set_bit(RSEQ_EVENT_SIGNAL_BIT, ¤t->rseq_event_mask); 2325 preempt_enable(); 2326 rseq_handle_notify_resume(ksig, regs); 2327 } 2328 2329 /* rseq_preempt() requires preemption to be disabled. */ 2330 static inline void rseq_preempt(struct task_struct *t) 2331 { 2332 __set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask); 2333 rseq_set_notify_resume(t); 2334 } 2335 2336 /* rseq_migrate() requires preemption to be disabled. */ 2337 static inline void rseq_migrate(struct task_struct *t) 2338 { 2339 __set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask); 2340 rseq_set_notify_resume(t); 2341 } 2342 2343 /* 2344 * If parent process has a registered restartable sequences area, the 2345 * child inherits. Unregister rseq for a clone with CLONE_VM set. 2346 */ 2347 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags) 2348 { 2349 if (clone_flags & CLONE_VM) { 2350 t->rseq = NULL; 2351 t->rseq_sig = 0; 2352 t->rseq_event_mask = 0; 2353 } else { 2354 t->rseq = current->rseq; 2355 t->rseq_sig = current->rseq_sig; 2356 t->rseq_event_mask = current->rseq_event_mask; 2357 } 2358 } 2359 2360 static inline void rseq_execve(struct task_struct *t) 2361 { 2362 t->rseq = NULL; 2363 t->rseq_sig = 0; 2364 t->rseq_event_mask = 0; 2365 } 2366 2367 #else 2368 2369 static inline void rseq_set_notify_resume(struct task_struct *t) 2370 { 2371 } 2372 static inline void rseq_handle_notify_resume(struct ksignal *ksig, 2373 struct pt_regs *regs) 2374 { 2375 } 2376 static inline void rseq_signal_deliver(struct ksignal *ksig, 2377 struct pt_regs *regs) 2378 { 2379 } 2380 static inline void rseq_preempt(struct task_struct *t) 2381 { 2382 } 2383 static inline void rseq_migrate(struct task_struct *t) 2384 { 2385 } 2386 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags) 2387 { 2388 } 2389 static inline void rseq_execve(struct task_struct *t) 2390 { 2391 } 2392 2393 #endif 2394 2395 #ifdef CONFIG_DEBUG_RSEQ 2396 2397 void rseq_syscall(struct pt_regs *regs); 2398 2399 #else 2400 2401 static inline void rseq_syscall(struct pt_regs *regs) 2402 { 2403 } 2404 2405 #endif 2406 2407 #ifdef CONFIG_SCHED_CORE 2408 extern void sched_core_free(struct task_struct *tsk); 2409 extern void sched_core_fork(struct task_struct *p); 2410 extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type, 2411 unsigned long uaddr); 2412 #else 2413 static inline void sched_core_free(struct task_struct *tsk) { } 2414 static inline void sched_core_fork(struct task_struct *p) { } 2415 #endif 2416 2417 extern void sched_set_stop_task(int cpu, struct task_struct *stop); 2418 2419 #endif 2420