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 <asm/kmap_size.h> 38 39 /* task_struct member predeclarations (sorted alphabetically): */ 40 struct audit_context; 41 struct backing_dev_info; 42 struct bio_list; 43 struct blk_plug; 44 struct bpf_local_storage; 45 struct bpf_run_ctx; 46 struct capture_control; 47 struct cfs_rq; 48 struct fs_struct; 49 struct futex_pi_state; 50 struct io_context; 51 struct io_uring_task; 52 struct mempolicy; 53 struct nameidata; 54 struct nsproxy; 55 struct perf_event_context; 56 struct pid_namespace; 57 struct pipe_inode_info; 58 struct rcu_node; 59 struct reclaim_state; 60 struct robust_list_head; 61 struct root_domain; 62 struct rq; 63 struct sched_attr; 64 struct sched_param; 65 struct seq_file; 66 struct sighand_struct; 67 struct signal_struct; 68 struct task_delay_info; 69 struct task_group; 70 71 /* 72 * Task state bitmask. NOTE! These bits are also 73 * encoded in fs/proc/array.c: get_task_state(). 74 * 75 * We have two separate sets of flags: task->state 76 * is about runnability, while task->exit_state are 77 * about the task exiting. Confusing, but this way 78 * modifying one set can't modify the other one by 79 * mistake. 80 */ 81 82 /* Used in tsk->state: */ 83 #define TASK_RUNNING 0x0000 84 #define TASK_INTERRUPTIBLE 0x0001 85 #define TASK_UNINTERRUPTIBLE 0x0002 86 #define __TASK_STOPPED 0x0004 87 #define __TASK_TRACED 0x0008 88 /* Used in tsk->exit_state: */ 89 #define EXIT_DEAD 0x0010 90 #define EXIT_ZOMBIE 0x0020 91 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD) 92 /* Used in tsk->state again: */ 93 #define TASK_PARKED 0x0040 94 #define TASK_DEAD 0x0080 95 #define TASK_WAKEKILL 0x0100 96 #define TASK_WAKING 0x0200 97 #define TASK_NOLOAD 0x0400 98 #define TASK_NEW 0x0800 99 /* RT specific auxilliary flag to mark RT lock waiters */ 100 #define TASK_RTLOCK_WAIT 0x1000 101 #define TASK_STATE_MAX 0x2000 102 103 /* Convenience macros for the sake of set_current_state: */ 104 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE) 105 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED) 106 #define TASK_TRACED (TASK_WAKEKILL | __TASK_TRACED) 107 108 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD) 109 110 /* Convenience macros for the sake of wake_up(): */ 111 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE) 112 113 /* get_task_state(): */ 114 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \ 115 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \ 116 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \ 117 TASK_PARKED) 118 119 #define task_is_running(task) (READ_ONCE((task)->__state) == TASK_RUNNING) 120 121 #define task_is_traced(task) ((READ_ONCE(task->__state) & __TASK_TRACED) != 0) 122 123 #define task_is_stopped(task) ((READ_ONCE(task->__state) & __TASK_STOPPED) != 0) 124 125 #define task_is_stopped_or_traced(task) ((READ_ONCE(task->__state) & (__TASK_STOPPED | __TASK_TRACED)) != 0) 126 127 /* 128 * Special states are those that do not use the normal wait-loop pattern. See 129 * the comment with set_special_state(). 130 */ 131 #define is_special_task_state(state) \ 132 ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD)) 133 134 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 135 # define debug_normal_state_change(state_value) \ 136 do { \ 137 WARN_ON_ONCE(is_special_task_state(state_value)); \ 138 current->task_state_change = _THIS_IP_; \ 139 } while (0) 140 141 # define debug_special_state_change(state_value) \ 142 do { \ 143 WARN_ON_ONCE(!is_special_task_state(state_value)); \ 144 current->task_state_change = _THIS_IP_; \ 145 } while (0) 146 147 # define debug_rtlock_wait_set_state() \ 148 do { \ 149 current->saved_state_change = current->task_state_change;\ 150 current->task_state_change = _THIS_IP_; \ 151 } while (0) 152 153 # define debug_rtlock_wait_restore_state() \ 154 do { \ 155 current->task_state_change = current->saved_state_change;\ 156 } while (0) 157 158 #else 159 # define debug_normal_state_change(cond) do { } while (0) 160 # define debug_special_state_change(cond) do { } while (0) 161 # define debug_rtlock_wait_set_state() do { } while (0) 162 # define debug_rtlock_wait_restore_state() do { } while (0) 163 #endif 164 165 /* 166 * set_current_state() includes a barrier so that the write of current->state 167 * is correctly serialised wrt the caller's subsequent test of whether to 168 * actually sleep: 169 * 170 * for (;;) { 171 * set_current_state(TASK_UNINTERRUPTIBLE); 172 * if (CONDITION) 173 * break; 174 * 175 * schedule(); 176 * } 177 * __set_current_state(TASK_RUNNING); 178 * 179 * If the caller does not need such serialisation (because, for instance, the 180 * CONDITION test and condition change and wakeup are under the same lock) then 181 * use __set_current_state(). 182 * 183 * The above is typically ordered against the wakeup, which does: 184 * 185 * CONDITION = 1; 186 * wake_up_state(p, TASK_UNINTERRUPTIBLE); 187 * 188 * where wake_up_state()/try_to_wake_up() executes a full memory barrier before 189 * accessing p->state. 190 * 191 * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is, 192 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a 193 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING). 194 * 195 * However, with slightly different timing the wakeup TASK_RUNNING store can 196 * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not 197 * a problem either because that will result in one extra go around the loop 198 * and our @cond test will save the day. 199 * 200 * Also see the comments of try_to_wake_up(). 201 */ 202 #define __set_current_state(state_value) \ 203 do { \ 204 debug_normal_state_change((state_value)); \ 205 WRITE_ONCE(current->__state, (state_value)); \ 206 } while (0) 207 208 #define set_current_state(state_value) \ 209 do { \ 210 debug_normal_state_change((state_value)); \ 211 smp_store_mb(current->__state, (state_value)); \ 212 } while (0) 213 214 /* 215 * set_special_state() should be used for those states when the blocking task 216 * can not use the regular condition based wait-loop. In that case we must 217 * serialize against wakeups such that any possible in-flight TASK_RUNNING 218 * stores will not collide with our state change. 219 */ 220 #define set_special_state(state_value) \ 221 do { \ 222 unsigned long flags; /* may shadow */ \ 223 \ 224 raw_spin_lock_irqsave(¤t->pi_lock, flags); \ 225 debug_special_state_change((state_value)); \ 226 WRITE_ONCE(current->__state, (state_value)); \ 227 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \ 228 } while (0) 229 230 /* 231 * PREEMPT_RT specific variants for "sleeping" spin/rwlocks 232 * 233 * RT's spin/rwlock substitutions are state preserving. The state of the 234 * task when blocking on the lock is saved in task_struct::saved_state and 235 * restored after the lock has been acquired. These operations are 236 * serialized by task_struct::pi_lock against try_to_wake_up(). Any non RT 237 * lock related wakeups while the task is blocked on the lock are 238 * redirected to operate on task_struct::saved_state to ensure that these 239 * are not dropped. On restore task_struct::saved_state is set to 240 * TASK_RUNNING so any wakeup attempt redirected to saved_state will fail. 241 * 242 * The lock operation looks like this: 243 * 244 * current_save_and_set_rtlock_wait_state(); 245 * for (;;) { 246 * if (try_lock()) 247 * break; 248 * raw_spin_unlock_irq(&lock->wait_lock); 249 * schedule_rtlock(); 250 * raw_spin_lock_irq(&lock->wait_lock); 251 * set_current_state(TASK_RTLOCK_WAIT); 252 * } 253 * current_restore_rtlock_saved_state(); 254 */ 255 #define current_save_and_set_rtlock_wait_state() \ 256 do { \ 257 lockdep_assert_irqs_disabled(); \ 258 raw_spin_lock(¤t->pi_lock); \ 259 current->saved_state = current->__state; \ 260 debug_rtlock_wait_set_state(); \ 261 WRITE_ONCE(current->__state, TASK_RTLOCK_WAIT); \ 262 raw_spin_unlock(¤t->pi_lock); \ 263 } while (0); 264 265 #define current_restore_rtlock_saved_state() \ 266 do { \ 267 lockdep_assert_irqs_disabled(); \ 268 raw_spin_lock(¤t->pi_lock); \ 269 debug_rtlock_wait_restore_state(); \ 270 WRITE_ONCE(current->__state, current->saved_state); \ 271 current->saved_state = TASK_RUNNING; \ 272 raw_spin_unlock(¤t->pi_lock); \ 273 } while (0); 274 275 #define get_current_state() READ_ONCE(current->__state) 276 277 /* 278 * Define the task command name length as enum, then it can be visible to 279 * BPF programs. 280 */ 281 enum { 282 TASK_COMM_LEN = 16, 283 }; 284 285 extern void scheduler_tick(void); 286 287 #define MAX_SCHEDULE_TIMEOUT LONG_MAX 288 289 extern long schedule_timeout(long timeout); 290 extern long schedule_timeout_interruptible(long timeout); 291 extern long schedule_timeout_killable(long timeout); 292 extern long schedule_timeout_uninterruptible(long timeout); 293 extern long schedule_timeout_idle(long timeout); 294 asmlinkage void schedule(void); 295 extern void schedule_preempt_disabled(void); 296 asmlinkage void preempt_schedule_irq(void); 297 #ifdef CONFIG_PREEMPT_RT 298 extern void schedule_rtlock(void); 299 #endif 300 301 extern int __must_check io_schedule_prepare(void); 302 extern void io_schedule_finish(int token); 303 extern long io_schedule_timeout(long timeout); 304 extern void io_schedule(void); 305 306 /** 307 * struct prev_cputime - snapshot of system and user cputime 308 * @utime: time spent in user mode 309 * @stime: time spent in system mode 310 * @lock: protects the above two fields 311 * 312 * Stores previous user/system time values such that we can guarantee 313 * monotonicity. 314 */ 315 struct prev_cputime { 316 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE 317 u64 utime; 318 u64 stime; 319 raw_spinlock_t lock; 320 #endif 321 }; 322 323 enum vtime_state { 324 /* Task is sleeping or running in a CPU with VTIME inactive: */ 325 VTIME_INACTIVE = 0, 326 /* Task is idle */ 327 VTIME_IDLE, 328 /* Task runs in kernelspace in a CPU with VTIME active: */ 329 VTIME_SYS, 330 /* Task runs in userspace in a CPU with VTIME active: */ 331 VTIME_USER, 332 /* Task runs as guests in a CPU with VTIME active: */ 333 VTIME_GUEST, 334 }; 335 336 struct vtime { 337 seqcount_t seqcount; 338 unsigned long long starttime; 339 enum vtime_state state; 340 unsigned int cpu; 341 u64 utime; 342 u64 stime; 343 u64 gtime; 344 }; 345 346 /* 347 * Utilization clamp constraints. 348 * @UCLAMP_MIN: Minimum utilization 349 * @UCLAMP_MAX: Maximum utilization 350 * @UCLAMP_CNT: Utilization clamp constraints count 351 */ 352 enum uclamp_id { 353 UCLAMP_MIN = 0, 354 UCLAMP_MAX, 355 UCLAMP_CNT 356 }; 357 358 #ifdef CONFIG_SMP 359 extern struct root_domain def_root_domain; 360 extern struct mutex sched_domains_mutex; 361 #endif 362 363 struct sched_info { 364 #ifdef CONFIG_SCHED_INFO 365 /* Cumulative counters: */ 366 367 /* # of times we have run on this CPU: */ 368 unsigned long pcount; 369 370 /* Time spent waiting on a runqueue: */ 371 unsigned long long run_delay; 372 373 /* Timestamps: */ 374 375 /* When did we last run on a CPU? */ 376 unsigned long long last_arrival; 377 378 /* When were we last queued to run? */ 379 unsigned long long last_queued; 380 381 #endif /* CONFIG_SCHED_INFO */ 382 }; 383 384 /* 385 * Integer metrics need fixed point arithmetic, e.g., sched/fair 386 * has a few: load, load_avg, util_avg, freq, and capacity. 387 * 388 * We define a basic fixed point arithmetic range, and then formalize 389 * all these metrics based on that basic range. 390 */ 391 # define SCHED_FIXEDPOINT_SHIFT 10 392 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT) 393 394 /* Increase resolution of cpu_capacity calculations */ 395 # define SCHED_CAPACITY_SHIFT SCHED_FIXEDPOINT_SHIFT 396 # define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT) 397 398 struct load_weight { 399 unsigned long weight; 400 u32 inv_weight; 401 }; 402 403 /** 404 * struct util_est - Estimation utilization of FAIR tasks 405 * @enqueued: instantaneous estimated utilization of a task/cpu 406 * @ewma: the Exponential Weighted Moving Average (EWMA) 407 * utilization of a task 408 * 409 * Support data structure to track an Exponential Weighted Moving Average 410 * (EWMA) of a FAIR task's utilization. New samples are added to the moving 411 * average each time a task completes an activation. Sample's weight is chosen 412 * so that the EWMA will be relatively insensitive to transient changes to the 413 * task's workload. 414 * 415 * The enqueued attribute has a slightly different meaning for tasks and cpus: 416 * - task: the task's util_avg at last task dequeue time 417 * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU 418 * Thus, the util_est.enqueued of a task represents the contribution on the 419 * estimated utilization of the CPU where that task is currently enqueued. 420 * 421 * Only for tasks we track a moving average of the past instantaneous 422 * estimated utilization. This allows to absorb sporadic drops in utilization 423 * of an otherwise almost periodic task. 424 * 425 * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg 426 * updates. When a task is dequeued, its util_est should not be updated if its 427 * util_avg has not been updated in the meantime. 428 * This information is mapped into the MSB bit of util_est.enqueued at dequeue 429 * time. Since max value of util_est.enqueued for a task is 1024 (PELT util_avg 430 * for a task) it is safe to use MSB. 431 */ 432 struct util_est { 433 unsigned int enqueued; 434 unsigned int ewma; 435 #define UTIL_EST_WEIGHT_SHIFT 2 436 #define UTIL_AVG_UNCHANGED 0x80000000 437 } __attribute__((__aligned__(sizeof(u64)))); 438 439 /* 440 * The load/runnable/util_avg accumulates an infinite geometric series 441 * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c). 442 * 443 * [load_avg definition] 444 * 445 * load_avg = runnable% * scale_load_down(load) 446 * 447 * [runnable_avg definition] 448 * 449 * runnable_avg = runnable% * SCHED_CAPACITY_SCALE 450 * 451 * [util_avg definition] 452 * 453 * util_avg = running% * SCHED_CAPACITY_SCALE 454 * 455 * where runnable% is the time ratio that a sched_entity is runnable and 456 * running% the time ratio that a sched_entity is running. 457 * 458 * For cfs_rq, they are the aggregated values of all runnable and blocked 459 * sched_entities. 460 * 461 * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU 462 * capacity scaling. The scaling is done through the rq_clock_pelt that is used 463 * for computing those signals (see update_rq_clock_pelt()) 464 * 465 * N.B., the above ratios (runnable% and running%) themselves are in the 466 * range of [0, 1]. To do fixed point arithmetics, we therefore scale them 467 * to as large a range as necessary. This is for example reflected by 468 * util_avg's SCHED_CAPACITY_SCALE. 469 * 470 * [Overflow issue] 471 * 472 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities 473 * with the highest load (=88761), always runnable on a single cfs_rq, 474 * and should not overflow as the number already hits PID_MAX_LIMIT. 475 * 476 * For all other cases (including 32-bit kernels), struct load_weight's 477 * weight will overflow first before we do, because: 478 * 479 * Max(load_avg) <= Max(load.weight) 480 * 481 * Then it is the load_weight's responsibility to consider overflow 482 * issues. 483 */ 484 struct sched_avg { 485 u64 last_update_time; 486 u64 load_sum; 487 u64 runnable_sum; 488 u32 util_sum; 489 u32 period_contrib; 490 unsigned long load_avg; 491 unsigned long runnable_avg; 492 unsigned long util_avg; 493 struct util_est util_est; 494 } ____cacheline_aligned; 495 496 struct sched_statistics { 497 #ifdef CONFIG_SCHEDSTATS 498 u64 wait_start; 499 u64 wait_max; 500 u64 wait_count; 501 u64 wait_sum; 502 u64 iowait_count; 503 u64 iowait_sum; 504 505 u64 sleep_start; 506 u64 sleep_max; 507 s64 sum_sleep_runtime; 508 509 u64 block_start; 510 u64 block_max; 511 s64 sum_block_runtime; 512 513 u64 exec_max; 514 u64 slice_max; 515 516 u64 nr_migrations_cold; 517 u64 nr_failed_migrations_affine; 518 u64 nr_failed_migrations_running; 519 u64 nr_failed_migrations_hot; 520 u64 nr_forced_migrations; 521 522 u64 nr_wakeups; 523 u64 nr_wakeups_sync; 524 u64 nr_wakeups_migrate; 525 u64 nr_wakeups_local; 526 u64 nr_wakeups_remote; 527 u64 nr_wakeups_affine; 528 u64 nr_wakeups_affine_attempts; 529 u64 nr_wakeups_passive; 530 u64 nr_wakeups_idle; 531 532 #ifdef CONFIG_SCHED_CORE 533 u64 core_forceidle_sum; 534 #endif 535 #endif /* CONFIG_SCHEDSTATS */ 536 } ____cacheline_aligned; 537 538 struct sched_entity { 539 /* For load-balancing: */ 540 struct load_weight load; 541 struct rb_node run_node; 542 struct list_head group_node; 543 unsigned int on_rq; 544 545 u64 exec_start; 546 u64 sum_exec_runtime; 547 u64 vruntime; 548 u64 prev_sum_exec_runtime; 549 550 u64 nr_migrations; 551 552 #ifdef CONFIG_FAIR_GROUP_SCHED 553 int depth; 554 struct sched_entity *parent; 555 /* rq on which this entity is (to be) queued: */ 556 struct cfs_rq *cfs_rq; 557 /* rq "owned" by this entity/group: */ 558 struct cfs_rq *my_q; 559 /* cached value of my_q->h_nr_running */ 560 unsigned long runnable_weight; 561 #endif 562 563 #ifdef CONFIG_SMP 564 /* 565 * Per entity load average tracking. 566 * 567 * Put into separate cache line so it does not 568 * collide with read-mostly values above. 569 */ 570 struct sched_avg avg; 571 #endif 572 }; 573 574 struct sched_rt_entity { 575 struct list_head run_list; 576 unsigned long timeout; 577 unsigned long watchdog_stamp; 578 unsigned int time_slice; 579 unsigned short on_rq; 580 unsigned short on_list; 581 582 struct sched_rt_entity *back; 583 #ifdef CONFIG_RT_GROUP_SCHED 584 struct sched_rt_entity *parent; 585 /* rq on which this entity is (to be) queued: */ 586 struct rt_rq *rt_rq; 587 /* rq "owned" by this entity/group: */ 588 struct rt_rq *my_q; 589 #endif 590 } __randomize_layout; 591 592 struct sched_dl_entity { 593 struct rb_node rb_node; 594 595 /* 596 * Original scheduling parameters. Copied here from sched_attr 597 * during sched_setattr(), they will remain the same until 598 * the next sched_setattr(). 599 */ 600 u64 dl_runtime; /* Maximum runtime for each instance */ 601 u64 dl_deadline; /* Relative deadline of each instance */ 602 u64 dl_period; /* Separation of two instances (period) */ 603 u64 dl_bw; /* dl_runtime / dl_period */ 604 u64 dl_density; /* dl_runtime / dl_deadline */ 605 606 /* 607 * Actual scheduling parameters. Initialized with the values above, 608 * they are continuously updated during task execution. Note that 609 * the remaining runtime could be < 0 in case we are in overrun. 610 */ 611 s64 runtime; /* Remaining runtime for this instance */ 612 u64 deadline; /* Absolute deadline for this instance */ 613 unsigned int flags; /* Specifying the scheduler behaviour */ 614 615 /* 616 * Some bool flags: 617 * 618 * @dl_throttled tells if we exhausted the runtime. If so, the 619 * task has to wait for a replenishment to be performed at the 620 * next firing of dl_timer. 621 * 622 * @dl_yielded tells if task gave up the CPU before consuming 623 * all its available runtime during the last job. 624 * 625 * @dl_non_contending tells if the task is inactive while still 626 * contributing to the active utilization. In other words, it 627 * indicates if the inactive timer has been armed and its handler 628 * has not been executed yet. This flag is useful to avoid race 629 * conditions between the inactive timer handler and the wakeup 630 * code. 631 * 632 * @dl_overrun tells if the task asked to be informed about runtime 633 * overruns. 634 */ 635 unsigned int dl_throttled : 1; 636 unsigned int dl_yielded : 1; 637 unsigned int dl_non_contending : 1; 638 unsigned int dl_overrun : 1; 639 640 /* 641 * Bandwidth enforcement timer. Each -deadline task has its 642 * own bandwidth to be enforced, thus we need one timer per task. 643 */ 644 struct hrtimer dl_timer; 645 646 /* 647 * Inactive timer, responsible for decreasing the active utilization 648 * at the "0-lag time". When a -deadline task blocks, it contributes 649 * to GRUB's active utilization until the "0-lag time", hence a 650 * timer is needed to decrease the active utilization at the correct 651 * time. 652 */ 653 struct hrtimer inactive_timer; 654 655 #ifdef CONFIG_RT_MUTEXES 656 /* 657 * Priority Inheritance. When a DEADLINE scheduling entity is boosted 658 * pi_se points to the donor, otherwise points to the dl_se it belongs 659 * to (the original one/itself). 660 */ 661 struct sched_dl_entity *pi_se; 662 #endif 663 }; 664 665 #ifdef CONFIG_UCLAMP_TASK 666 /* Number of utilization clamp buckets (shorter alias) */ 667 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT 668 669 /* 670 * Utilization clamp for a scheduling entity 671 * @value: clamp value "assigned" to a se 672 * @bucket_id: bucket index corresponding to the "assigned" value 673 * @active: the se is currently refcounted in a rq's bucket 674 * @user_defined: the requested clamp value comes from user-space 675 * 676 * The bucket_id is the index of the clamp bucket matching the clamp value 677 * which is pre-computed and stored to avoid expensive integer divisions from 678 * the fast path. 679 * 680 * The active bit is set whenever a task has got an "effective" value assigned, 681 * which can be different from the clamp value "requested" from user-space. 682 * This allows to know a task is refcounted in the rq's bucket corresponding 683 * to the "effective" bucket_id. 684 * 685 * The user_defined bit is set whenever a task has got a task-specific clamp 686 * value requested from userspace, i.e. the system defaults apply to this task 687 * just as a restriction. This allows to relax default clamps when a less 688 * restrictive task-specific value has been requested, thus allowing to 689 * implement a "nice" semantic. For example, a task running with a 20% 690 * default boost can still drop its own boosting to 0%. 691 */ 692 struct uclamp_se { 693 unsigned int value : bits_per(SCHED_CAPACITY_SCALE); 694 unsigned int bucket_id : bits_per(UCLAMP_BUCKETS); 695 unsigned int active : 1; 696 unsigned int user_defined : 1; 697 }; 698 #endif /* CONFIG_UCLAMP_TASK */ 699 700 union rcu_special { 701 struct { 702 u8 blocked; 703 u8 need_qs; 704 u8 exp_hint; /* Hint for performance. */ 705 u8 need_mb; /* Readers need smp_mb(). */ 706 } b; /* Bits. */ 707 u32 s; /* Set of bits. */ 708 }; 709 710 enum perf_event_task_context { 711 perf_invalid_context = -1, 712 perf_hw_context = 0, 713 perf_sw_context, 714 perf_nr_task_contexts, 715 }; 716 717 struct wake_q_node { 718 struct wake_q_node *next; 719 }; 720 721 struct kmap_ctrl { 722 #ifdef CONFIG_KMAP_LOCAL 723 int idx; 724 pte_t pteval[KM_MAX_IDX]; 725 #endif 726 }; 727 728 struct task_struct { 729 #ifdef CONFIG_THREAD_INFO_IN_TASK 730 /* 731 * For reasons of header soup (see current_thread_info()), this 732 * must be the first element of task_struct. 733 */ 734 struct thread_info thread_info; 735 #endif 736 unsigned int __state; 737 738 #ifdef CONFIG_PREEMPT_RT 739 /* saved state for "spinlock sleepers" */ 740 unsigned int saved_state; 741 #endif 742 743 /* 744 * This begins the randomizable portion of task_struct. Only 745 * scheduling-critical items should be added above here. 746 */ 747 randomized_struct_fields_start 748 749 void *stack; 750 refcount_t usage; 751 /* Per task flags (PF_*), defined further below: */ 752 unsigned int flags; 753 unsigned int ptrace; 754 755 #ifdef CONFIG_SMP 756 int on_cpu; 757 struct __call_single_node wake_entry; 758 unsigned int wakee_flips; 759 unsigned long wakee_flip_decay_ts; 760 struct task_struct *last_wakee; 761 762 /* 763 * recent_used_cpu is initially set as the last CPU used by a task 764 * that wakes affine another task. Waker/wakee relationships can 765 * push tasks around a CPU where each wakeup moves to the next one. 766 * Tracking a recently used CPU allows a quick search for a recently 767 * used CPU that may be idle. 768 */ 769 int recent_used_cpu; 770 int wake_cpu; 771 #endif 772 int on_rq; 773 774 int prio; 775 int static_prio; 776 int normal_prio; 777 unsigned int rt_priority; 778 779 struct sched_entity se; 780 struct sched_rt_entity rt; 781 struct sched_dl_entity dl; 782 const struct sched_class *sched_class; 783 784 #ifdef CONFIG_SCHED_CORE 785 struct rb_node core_node; 786 unsigned long core_cookie; 787 unsigned int core_occupation; 788 #endif 789 790 #ifdef CONFIG_CGROUP_SCHED 791 struct task_group *sched_task_group; 792 #endif 793 794 #ifdef CONFIG_UCLAMP_TASK 795 /* 796 * Clamp values requested for a scheduling entity. 797 * Must be updated with task_rq_lock() held. 798 */ 799 struct uclamp_se uclamp_req[UCLAMP_CNT]; 800 /* 801 * Effective clamp values used for a scheduling entity. 802 * Must be updated with task_rq_lock() held. 803 */ 804 struct uclamp_se uclamp[UCLAMP_CNT]; 805 #endif 806 807 struct sched_statistics stats; 808 809 #ifdef CONFIG_PREEMPT_NOTIFIERS 810 /* List of struct preempt_notifier: */ 811 struct hlist_head preempt_notifiers; 812 #endif 813 814 #ifdef CONFIG_BLK_DEV_IO_TRACE 815 unsigned int btrace_seq; 816 #endif 817 818 unsigned int policy; 819 int nr_cpus_allowed; 820 const cpumask_t *cpus_ptr; 821 cpumask_t *user_cpus_ptr; 822 cpumask_t cpus_mask; 823 void *migration_pending; 824 #ifdef CONFIG_SMP 825 unsigned short migration_disabled; 826 #endif 827 unsigned short migration_flags; 828 829 #ifdef CONFIG_PREEMPT_RCU 830 int rcu_read_lock_nesting; 831 union rcu_special rcu_read_unlock_special; 832 struct list_head rcu_node_entry; 833 struct rcu_node *rcu_blocked_node; 834 #endif /* #ifdef CONFIG_PREEMPT_RCU */ 835 836 #ifdef CONFIG_TASKS_RCU 837 unsigned long rcu_tasks_nvcsw; 838 u8 rcu_tasks_holdout; 839 u8 rcu_tasks_idx; 840 int rcu_tasks_idle_cpu; 841 struct list_head rcu_tasks_holdout_list; 842 #endif /* #ifdef CONFIG_TASKS_RCU */ 843 844 #ifdef CONFIG_TASKS_TRACE_RCU 845 int trc_reader_nesting; 846 int trc_ipi_to_cpu; 847 union rcu_special trc_reader_special; 848 bool trc_reader_checked; 849 struct list_head trc_holdout_list; 850 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */ 851 852 struct sched_info sched_info; 853 854 struct list_head tasks; 855 #ifdef CONFIG_SMP 856 struct plist_node pushable_tasks; 857 struct rb_node pushable_dl_tasks; 858 #endif 859 860 struct mm_struct *mm; 861 struct mm_struct *active_mm; 862 863 /* Per-thread vma caching: */ 864 struct vmacache vmacache; 865 866 #ifdef SPLIT_RSS_COUNTING 867 struct task_rss_stat rss_stat; 868 #endif 869 int exit_state; 870 int exit_code; 871 int exit_signal; 872 /* The signal sent when the parent dies: */ 873 int pdeath_signal; 874 /* JOBCTL_*, siglock protected: */ 875 unsigned long jobctl; 876 877 /* Used for emulating ABI behavior of previous Linux versions: */ 878 unsigned int personality; 879 880 /* Scheduler bits, serialized by scheduler locks: */ 881 unsigned sched_reset_on_fork:1; 882 unsigned sched_contributes_to_load:1; 883 unsigned sched_migrated:1; 884 #ifdef CONFIG_PSI 885 unsigned sched_psi_wake_requeue:1; 886 #endif 887 888 /* Force alignment to the next boundary: */ 889 unsigned :0; 890 891 /* Unserialized, strictly 'current' */ 892 893 /* 894 * This field must not be in the scheduler word above due to wakelist 895 * queueing no longer being serialized by p->on_cpu. However: 896 * 897 * p->XXX = X; ttwu() 898 * schedule() if (p->on_rq && ..) // false 899 * smp_mb__after_spinlock(); if (smp_load_acquire(&p->on_cpu) && //true 900 * deactivate_task() ttwu_queue_wakelist()) 901 * p->on_rq = 0; p->sched_remote_wakeup = Y; 902 * 903 * guarantees all stores of 'current' are visible before 904 * ->sched_remote_wakeup gets used, so it can be in this word. 905 */ 906 unsigned sched_remote_wakeup:1; 907 908 /* Bit to tell LSMs we're in execve(): */ 909 unsigned in_execve:1; 910 unsigned in_iowait:1; 911 #ifndef TIF_RESTORE_SIGMASK 912 unsigned restore_sigmask:1; 913 #endif 914 #ifdef CONFIG_MEMCG 915 unsigned in_user_fault:1; 916 #endif 917 #ifdef CONFIG_COMPAT_BRK 918 unsigned brk_randomized:1; 919 #endif 920 #ifdef CONFIG_CGROUPS 921 /* disallow userland-initiated cgroup migration */ 922 unsigned no_cgroup_migration:1; 923 /* task is frozen/stopped (used by the cgroup freezer) */ 924 unsigned frozen:1; 925 #endif 926 #ifdef CONFIG_BLK_CGROUP 927 unsigned use_memdelay:1; 928 #endif 929 #ifdef CONFIG_PSI 930 /* Stalled due to lack of memory */ 931 unsigned in_memstall:1; 932 #endif 933 #ifdef CONFIG_PAGE_OWNER 934 /* Used by page_owner=on to detect recursion in page tracking. */ 935 unsigned in_page_owner:1; 936 #endif 937 #ifdef CONFIG_EVENTFD 938 /* Recursion prevention for eventfd_signal() */ 939 unsigned in_eventfd_signal:1; 940 #endif 941 #ifdef CONFIG_IOMMU_SVA 942 unsigned pasid_activated:1; 943 #endif 944 #ifdef CONFIG_CPU_SUP_INTEL 945 unsigned reported_split_lock:1; 946 #endif 947 948 unsigned long atomic_flags; /* Flags requiring atomic access. */ 949 950 struct restart_block restart_block; 951 952 pid_t pid; 953 pid_t tgid; 954 955 #ifdef CONFIG_STACKPROTECTOR 956 /* Canary value for the -fstack-protector GCC feature: */ 957 unsigned long stack_canary; 958 #endif 959 /* 960 * Pointers to the (original) parent process, youngest child, younger sibling, 961 * older sibling, respectively. (p->father can be replaced with 962 * p->real_parent->pid) 963 */ 964 965 /* Real parent process: */ 966 struct task_struct __rcu *real_parent; 967 968 /* Recipient of SIGCHLD, wait4() reports: */ 969 struct task_struct __rcu *parent; 970 971 /* 972 * Children/sibling form the list of natural children: 973 */ 974 struct list_head children; 975 struct list_head sibling; 976 struct task_struct *group_leader; 977 978 /* 979 * 'ptraced' is the list of tasks this task is using ptrace() on. 980 * 981 * This includes both natural children and PTRACE_ATTACH targets. 982 * 'ptrace_entry' is this task's link on the p->parent->ptraced list. 983 */ 984 struct list_head ptraced; 985 struct list_head ptrace_entry; 986 987 /* PID/PID hash table linkage. */ 988 struct pid *thread_pid; 989 struct hlist_node pid_links[PIDTYPE_MAX]; 990 struct list_head thread_group; 991 struct list_head thread_node; 992 993 struct completion *vfork_done; 994 995 /* CLONE_CHILD_SETTID: */ 996 int __user *set_child_tid; 997 998 /* CLONE_CHILD_CLEARTID: */ 999 int __user *clear_child_tid; 1000 1001 /* PF_KTHREAD | PF_IO_WORKER */ 1002 void *worker_private; 1003 1004 u64 utime; 1005 u64 stime; 1006 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME 1007 u64 utimescaled; 1008 u64 stimescaled; 1009 #endif 1010 u64 gtime; 1011 struct prev_cputime prev_cputime; 1012 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN 1013 struct vtime vtime; 1014 #endif 1015 1016 #ifdef CONFIG_NO_HZ_FULL 1017 atomic_t tick_dep_mask; 1018 #endif 1019 /* Context switch counts: */ 1020 unsigned long nvcsw; 1021 unsigned long nivcsw; 1022 1023 /* Monotonic time in nsecs: */ 1024 u64 start_time; 1025 1026 /* Boot based time in nsecs: */ 1027 u64 start_boottime; 1028 1029 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */ 1030 unsigned long min_flt; 1031 unsigned long maj_flt; 1032 1033 /* Empty if CONFIG_POSIX_CPUTIMERS=n */ 1034 struct posix_cputimers posix_cputimers; 1035 1036 #ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK 1037 struct posix_cputimers_work posix_cputimers_work; 1038 #endif 1039 1040 /* Process credentials: */ 1041 1042 /* Tracer's credentials at attach: */ 1043 const struct cred __rcu *ptracer_cred; 1044 1045 /* Objective and real subjective task credentials (COW): */ 1046 const struct cred __rcu *real_cred; 1047 1048 /* Effective (overridable) subjective task credentials (COW): */ 1049 const struct cred __rcu *cred; 1050 1051 #ifdef CONFIG_KEYS 1052 /* Cached requested key. */ 1053 struct key *cached_requested_key; 1054 #endif 1055 1056 /* 1057 * executable name, excluding path. 1058 * 1059 * - normally initialized setup_new_exec() 1060 * - access it with [gs]et_task_comm() 1061 * - lock it with task_lock() 1062 */ 1063 char comm[TASK_COMM_LEN]; 1064 1065 struct nameidata *nameidata; 1066 1067 #ifdef CONFIG_SYSVIPC 1068 struct sysv_sem sysvsem; 1069 struct sysv_shm sysvshm; 1070 #endif 1071 #ifdef CONFIG_DETECT_HUNG_TASK 1072 unsigned long last_switch_count; 1073 unsigned long last_switch_time; 1074 #endif 1075 /* Filesystem information: */ 1076 struct fs_struct *fs; 1077 1078 /* Open file information: */ 1079 struct files_struct *files; 1080 1081 #ifdef CONFIG_IO_URING 1082 struct io_uring_task *io_uring; 1083 #endif 1084 1085 /* Namespaces: */ 1086 struct nsproxy *nsproxy; 1087 1088 /* Signal handlers: */ 1089 struct signal_struct *signal; 1090 struct sighand_struct __rcu *sighand; 1091 sigset_t blocked; 1092 sigset_t real_blocked; 1093 /* Restored if set_restore_sigmask() was used: */ 1094 sigset_t saved_sigmask; 1095 struct sigpending pending; 1096 unsigned long sas_ss_sp; 1097 size_t sas_ss_size; 1098 unsigned int sas_ss_flags; 1099 1100 struct callback_head *task_works; 1101 1102 #ifdef CONFIG_AUDIT 1103 #ifdef CONFIG_AUDITSYSCALL 1104 struct audit_context *audit_context; 1105 #endif 1106 kuid_t loginuid; 1107 unsigned int sessionid; 1108 #endif 1109 struct seccomp seccomp; 1110 struct syscall_user_dispatch syscall_dispatch; 1111 1112 /* Thread group tracking: */ 1113 u64 parent_exec_id; 1114 u64 self_exec_id; 1115 1116 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */ 1117 spinlock_t alloc_lock; 1118 1119 /* Protection of the PI data structures: */ 1120 raw_spinlock_t pi_lock; 1121 1122 struct wake_q_node wake_q; 1123 1124 #ifdef CONFIG_RT_MUTEXES 1125 /* PI waiters blocked on a rt_mutex held by this task: */ 1126 struct rb_root_cached pi_waiters; 1127 /* Updated under owner's pi_lock and rq lock */ 1128 struct task_struct *pi_top_task; 1129 /* Deadlock detection and priority inheritance handling: */ 1130 struct rt_mutex_waiter *pi_blocked_on; 1131 #endif 1132 1133 #ifdef CONFIG_DEBUG_MUTEXES 1134 /* Mutex deadlock detection: */ 1135 struct mutex_waiter *blocked_on; 1136 #endif 1137 1138 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1139 int non_block_count; 1140 #endif 1141 1142 #ifdef CONFIG_TRACE_IRQFLAGS 1143 struct irqtrace_events irqtrace; 1144 unsigned int hardirq_threaded; 1145 u64 hardirq_chain_key; 1146 int softirqs_enabled; 1147 int softirq_context; 1148 int irq_config; 1149 #endif 1150 #ifdef CONFIG_PREEMPT_RT 1151 int softirq_disable_cnt; 1152 #endif 1153 1154 #ifdef CONFIG_LOCKDEP 1155 # define MAX_LOCK_DEPTH 48UL 1156 u64 curr_chain_key; 1157 int lockdep_depth; 1158 unsigned int lockdep_recursion; 1159 struct held_lock held_locks[MAX_LOCK_DEPTH]; 1160 #endif 1161 1162 #if defined(CONFIG_UBSAN) && !defined(CONFIG_UBSAN_TRAP) 1163 unsigned int in_ubsan; 1164 #endif 1165 1166 /* Journalling filesystem info: */ 1167 void *journal_info; 1168 1169 /* Stacked block device info: */ 1170 struct bio_list *bio_list; 1171 1172 /* Stack plugging: */ 1173 struct blk_plug *plug; 1174 1175 /* VM state: */ 1176 struct reclaim_state *reclaim_state; 1177 1178 struct backing_dev_info *backing_dev_info; 1179 1180 struct io_context *io_context; 1181 1182 #ifdef CONFIG_COMPACTION 1183 struct capture_control *capture_control; 1184 #endif 1185 /* Ptrace state: */ 1186 unsigned long ptrace_message; 1187 kernel_siginfo_t *last_siginfo; 1188 1189 struct task_io_accounting ioac; 1190 #ifdef CONFIG_PSI 1191 /* Pressure stall state */ 1192 unsigned int psi_flags; 1193 #endif 1194 #ifdef CONFIG_TASK_XACCT 1195 /* Accumulated RSS usage: */ 1196 u64 acct_rss_mem1; 1197 /* Accumulated virtual memory usage: */ 1198 u64 acct_vm_mem1; 1199 /* stime + utime since last update: */ 1200 u64 acct_timexpd; 1201 #endif 1202 #ifdef CONFIG_CPUSETS 1203 /* Protected by ->alloc_lock: */ 1204 nodemask_t mems_allowed; 1205 /* Sequence number to catch updates: */ 1206 seqcount_spinlock_t mems_allowed_seq; 1207 int cpuset_mem_spread_rotor; 1208 int cpuset_slab_spread_rotor; 1209 #endif 1210 #ifdef CONFIG_CGROUPS 1211 /* Control Group info protected by css_set_lock: */ 1212 struct css_set __rcu *cgroups; 1213 /* cg_list protected by css_set_lock and tsk->alloc_lock: */ 1214 struct list_head cg_list; 1215 #endif 1216 #ifdef CONFIG_X86_CPU_RESCTRL 1217 u32 closid; 1218 u32 rmid; 1219 #endif 1220 #ifdef CONFIG_FUTEX 1221 struct robust_list_head __user *robust_list; 1222 #ifdef CONFIG_COMPAT 1223 struct compat_robust_list_head __user *compat_robust_list; 1224 #endif 1225 struct list_head pi_state_list; 1226 struct futex_pi_state *pi_state_cache; 1227 struct mutex futex_exit_mutex; 1228 unsigned int futex_state; 1229 #endif 1230 #ifdef CONFIG_PERF_EVENTS 1231 struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts]; 1232 struct mutex perf_event_mutex; 1233 struct list_head perf_event_list; 1234 #endif 1235 #ifdef CONFIG_DEBUG_PREEMPT 1236 unsigned long preempt_disable_ip; 1237 #endif 1238 #ifdef CONFIG_NUMA 1239 /* Protected by alloc_lock: */ 1240 struct mempolicy *mempolicy; 1241 short il_prev; 1242 short pref_node_fork; 1243 #endif 1244 #ifdef CONFIG_NUMA_BALANCING 1245 int numa_scan_seq; 1246 unsigned int numa_scan_period; 1247 unsigned int numa_scan_period_max; 1248 int numa_preferred_nid; 1249 unsigned long numa_migrate_retry; 1250 /* Migration stamp: */ 1251 u64 node_stamp; 1252 u64 last_task_numa_placement; 1253 u64 last_sum_exec_runtime; 1254 struct callback_head numa_work; 1255 1256 /* 1257 * This pointer is only modified for current in syscall and 1258 * pagefault context (and for tasks being destroyed), so it can be read 1259 * from any of the following contexts: 1260 * - RCU read-side critical section 1261 * - current->numa_group from everywhere 1262 * - task's runqueue locked, task not running 1263 */ 1264 struct numa_group __rcu *numa_group; 1265 1266 /* 1267 * numa_faults is an array split into four regions: 1268 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer 1269 * in this precise order. 1270 * 1271 * faults_memory: Exponential decaying average of faults on a per-node 1272 * basis. Scheduling placement decisions are made based on these 1273 * counts. The values remain static for the duration of a PTE scan. 1274 * faults_cpu: Track the nodes the process was running on when a NUMA 1275 * hinting fault was incurred. 1276 * faults_memory_buffer and faults_cpu_buffer: Record faults per node 1277 * during the current scan window. When the scan completes, the counts 1278 * in faults_memory and faults_cpu decay and these values are copied. 1279 */ 1280 unsigned long *numa_faults; 1281 unsigned long total_numa_faults; 1282 1283 /* 1284 * numa_faults_locality tracks if faults recorded during the last 1285 * scan window were remote/local or failed to migrate. The task scan 1286 * period is adapted based on the locality of the faults with different 1287 * weights depending on whether they were shared or private faults 1288 */ 1289 unsigned long numa_faults_locality[3]; 1290 1291 unsigned long numa_pages_migrated; 1292 #endif /* CONFIG_NUMA_BALANCING */ 1293 1294 #ifdef CONFIG_RSEQ 1295 struct rseq __user *rseq; 1296 u32 rseq_sig; 1297 /* 1298 * RmW on rseq_event_mask must be performed atomically 1299 * with respect to preemption. 1300 */ 1301 unsigned long rseq_event_mask; 1302 #endif 1303 1304 struct tlbflush_unmap_batch tlb_ubc; 1305 1306 union { 1307 refcount_t rcu_users; 1308 struct rcu_head rcu; 1309 }; 1310 1311 /* Cache last used pipe for splice(): */ 1312 struct pipe_inode_info *splice_pipe; 1313 1314 struct page_frag task_frag; 1315 1316 #ifdef CONFIG_TASK_DELAY_ACCT 1317 struct task_delay_info *delays; 1318 #endif 1319 1320 #ifdef CONFIG_FAULT_INJECTION 1321 int make_it_fail; 1322 unsigned int fail_nth; 1323 #endif 1324 /* 1325 * When (nr_dirtied >= nr_dirtied_pause), it's time to call 1326 * balance_dirty_pages() for a dirty throttling pause: 1327 */ 1328 int nr_dirtied; 1329 int nr_dirtied_pause; 1330 /* Start of a write-and-pause period: */ 1331 unsigned long dirty_paused_when; 1332 1333 #ifdef CONFIG_LATENCYTOP 1334 int latency_record_count; 1335 struct latency_record latency_record[LT_SAVECOUNT]; 1336 #endif 1337 /* 1338 * Time slack values; these are used to round up poll() and 1339 * select() etc timeout values. These are in nanoseconds. 1340 */ 1341 u64 timer_slack_ns; 1342 u64 default_timer_slack_ns; 1343 1344 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) 1345 unsigned int kasan_depth; 1346 #endif 1347 1348 #ifdef CONFIG_KCSAN 1349 struct kcsan_ctx kcsan_ctx; 1350 #ifdef CONFIG_TRACE_IRQFLAGS 1351 struct irqtrace_events kcsan_save_irqtrace; 1352 #endif 1353 #ifdef CONFIG_KCSAN_WEAK_MEMORY 1354 int kcsan_stack_depth; 1355 #endif 1356 #endif 1357 1358 #if IS_ENABLED(CONFIG_KUNIT) 1359 struct kunit *kunit_test; 1360 #endif 1361 1362 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 1363 /* Index of current stored address in ret_stack: */ 1364 int curr_ret_stack; 1365 int curr_ret_depth; 1366 1367 /* Stack of return addresses for return function tracing: */ 1368 struct ftrace_ret_stack *ret_stack; 1369 1370 /* Timestamp for last schedule: */ 1371 unsigned long long ftrace_timestamp; 1372 1373 /* 1374 * Number of functions that haven't been traced 1375 * because of depth overrun: 1376 */ 1377 atomic_t trace_overrun; 1378 1379 /* Pause tracing: */ 1380 atomic_t tracing_graph_pause; 1381 #endif 1382 1383 #ifdef CONFIG_TRACING 1384 /* State flags for use by tracers: */ 1385 unsigned long trace; 1386 1387 /* Bitmask and counter of trace recursion: */ 1388 unsigned long trace_recursion; 1389 #endif /* CONFIG_TRACING */ 1390 1391 #ifdef CONFIG_KCOV 1392 /* See kernel/kcov.c for more details. */ 1393 1394 /* Coverage collection mode enabled for this task (0 if disabled): */ 1395 unsigned int kcov_mode; 1396 1397 /* Size of the kcov_area: */ 1398 unsigned int kcov_size; 1399 1400 /* Buffer for coverage collection: */ 1401 void *kcov_area; 1402 1403 /* KCOV descriptor wired with this task or NULL: */ 1404 struct kcov *kcov; 1405 1406 /* KCOV common handle for remote coverage collection: */ 1407 u64 kcov_handle; 1408 1409 /* KCOV sequence number: */ 1410 int kcov_sequence; 1411 1412 /* Collect coverage from softirq context: */ 1413 unsigned int kcov_softirq; 1414 #endif 1415 1416 #ifdef CONFIG_MEMCG 1417 struct mem_cgroup *memcg_in_oom; 1418 gfp_t memcg_oom_gfp_mask; 1419 int memcg_oom_order; 1420 1421 /* Number of pages to reclaim on returning to userland: */ 1422 unsigned int memcg_nr_pages_over_high; 1423 1424 /* Used by memcontrol for targeted memcg charge: */ 1425 struct mem_cgroup *active_memcg; 1426 #endif 1427 1428 #ifdef CONFIG_BLK_CGROUP 1429 struct request_queue *throttle_queue; 1430 #endif 1431 1432 #ifdef CONFIG_UPROBES 1433 struct uprobe_task *utask; 1434 #endif 1435 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE) 1436 unsigned int sequential_io; 1437 unsigned int sequential_io_avg; 1438 #endif 1439 struct kmap_ctrl kmap_ctrl; 1440 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1441 unsigned long task_state_change; 1442 # ifdef CONFIG_PREEMPT_RT 1443 unsigned long saved_state_change; 1444 # endif 1445 #endif 1446 int pagefault_disabled; 1447 #ifdef CONFIG_MMU 1448 struct task_struct *oom_reaper_list; 1449 struct timer_list oom_reaper_timer; 1450 #endif 1451 #ifdef CONFIG_VMAP_STACK 1452 struct vm_struct *stack_vm_area; 1453 #endif 1454 #ifdef CONFIG_THREAD_INFO_IN_TASK 1455 /* A live task holds one reference: */ 1456 refcount_t stack_refcount; 1457 #endif 1458 #ifdef CONFIG_LIVEPATCH 1459 int patch_state; 1460 #endif 1461 #ifdef CONFIG_SECURITY 1462 /* Used by LSM modules for access restriction: */ 1463 void *security; 1464 #endif 1465 #ifdef CONFIG_BPF_SYSCALL 1466 /* Used by BPF task local storage */ 1467 struct bpf_local_storage __rcu *bpf_storage; 1468 /* Used for BPF run context */ 1469 struct bpf_run_ctx *bpf_ctx; 1470 #endif 1471 1472 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK 1473 unsigned long lowest_stack; 1474 unsigned long prev_lowest_stack; 1475 #endif 1476 1477 #ifdef CONFIG_X86_MCE 1478 void __user *mce_vaddr; 1479 __u64 mce_kflags; 1480 u64 mce_addr; 1481 __u64 mce_ripv : 1, 1482 mce_whole_page : 1, 1483 __mce_reserved : 62; 1484 struct callback_head mce_kill_me; 1485 int mce_count; 1486 #endif 1487 1488 #ifdef CONFIG_KRETPROBES 1489 struct llist_head kretprobe_instances; 1490 #endif 1491 #ifdef CONFIG_RETHOOK 1492 struct llist_head rethooks; 1493 #endif 1494 1495 #ifdef CONFIG_ARCH_HAS_PARANOID_L1D_FLUSH 1496 /* 1497 * If L1D flush is supported on mm context switch 1498 * then we use this callback head to queue kill work 1499 * to kill tasks that are not running on SMT disabled 1500 * cores 1501 */ 1502 struct callback_head l1d_flush_kill; 1503 #endif 1504 1505 /* 1506 * New fields for task_struct should be added above here, so that 1507 * they are included in the randomized portion of task_struct. 1508 */ 1509 randomized_struct_fields_end 1510 1511 /* CPU-specific state of this task: */ 1512 struct thread_struct thread; 1513 1514 /* 1515 * WARNING: on x86, 'thread_struct' contains a variable-sized 1516 * structure. It *MUST* be at the end of 'task_struct'. 1517 * 1518 * Do not put anything below here! 1519 */ 1520 }; 1521 1522 static inline struct pid *task_pid(struct task_struct *task) 1523 { 1524 return task->thread_pid; 1525 } 1526 1527 /* 1528 * the helpers to get the task's different pids as they are seen 1529 * from various namespaces 1530 * 1531 * task_xid_nr() : global id, i.e. the id seen from the init namespace; 1532 * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of 1533 * current. 1534 * task_xid_nr_ns() : id seen from the ns specified; 1535 * 1536 * see also pid_nr() etc in include/linux/pid.h 1537 */ 1538 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns); 1539 1540 static inline pid_t task_pid_nr(struct task_struct *tsk) 1541 { 1542 return tsk->pid; 1543 } 1544 1545 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1546 { 1547 return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns); 1548 } 1549 1550 static inline pid_t task_pid_vnr(struct task_struct *tsk) 1551 { 1552 return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL); 1553 } 1554 1555 1556 static inline pid_t task_tgid_nr(struct task_struct *tsk) 1557 { 1558 return tsk->tgid; 1559 } 1560 1561 /** 1562 * pid_alive - check that a task structure is not stale 1563 * @p: Task structure to be checked. 1564 * 1565 * Test if a process is not yet dead (at most zombie state) 1566 * If pid_alive fails, then pointers within the task structure 1567 * can be stale and must not be dereferenced. 1568 * 1569 * Return: 1 if the process is alive. 0 otherwise. 1570 */ 1571 static inline int pid_alive(const struct task_struct *p) 1572 { 1573 return p->thread_pid != NULL; 1574 } 1575 1576 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1577 { 1578 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns); 1579 } 1580 1581 static inline pid_t task_pgrp_vnr(struct task_struct *tsk) 1582 { 1583 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL); 1584 } 1585 1586 1587 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1588 { 1589 return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns); 1590 } 1591 1592 static inline pid_t task_session_vnr(struct task_struct *tsk) 1593 { 1594 return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL); 1595 } 1596 1597 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1598 { 1599 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, ns); 1600 } 1601 1602 static inline pid_t task_tgid_vnr(struct task_struct *tsk) 1603 { 1604 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, NULL); 1605 } 1606 1607 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns) 1608 { 1609 pid_t pid = 0; 1610 1611 rcu_read_lock(); 1612 if (pid_alive(tsk)) 1613 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns); 1614 rcu_read_unlock(); 1615 1616 return pid; 1617 } 1618 1619 static inline pid_t task_ppid_nr(const struct task_struct *tsk) 1620 { 1621 return task_ppid_nr_ns(tsk, &init_pid_ns); 1622 } 1623 1624 /* Obsolete, do not use: */ 1625 static inline pid_t task_pgrp_nr(struct task_struct *tsk) 1626 { 1627 return task_pgrp_nr_ns(tsk, &init_pid_ns); 1628 } 1629 1630 #define TASK_REPORT_IDLE (TASK_REPORT + 1) 1631 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1) 1632 1633 static inline unsigned int __task_state_index(unsigned int tsk_state, 1634 unsigned int tsk_exit_state) 1635 { 1636 unsigned int state = (tsk_state | tsk_exit_state) & TASK_REPORT; 1637 1638 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX); 1639 1640 if (tsk_state == TASK_IDLE) 1641 state = TASK_REPORT_IDLE; 1642 1643 /* 1644 * We're lying here, but rather than expose a completely new task state 1645 * to userspace, we can make this appear as if the task has gone through 1646 * a regular rt_mutex_lock() call. 1647 */ 1648 if (tsk_state == TASK_RTLOCK_WAIT) 1649 state = TASK_UNINTERRUPTIBLE; 1650 1651 return fls(state); 1652 } 1653 1654 static inline unsigned int task_state_index(struct task_struct *tsk) 1655 { 1656 return __task_state_index(READ_ONCE(tsk->__state), tsk->exit_state); 1657 } 1658 1659 static inline char task_index_to_char(unsigned int state) 1660 { 1661 static const char state_char[] = "RSDTtXZPI"; 1662 1663 BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1); 1664 1665 return state_char[state]; 1666 } 1667 1668 static inline char task_state_to_char(struct task_struct *tsk) 1669 { 1670 return task_index_to_char(task_state_index(tsk)); 1671 } 1672 1673 /** 1674 * is_global_init - check if a task structure is init. Since init 1675 * is free to have sub-threads we need to check tgid. 1676 * @tsk: Task structure to be checked. 1677 * 1678 * Check if a task structure is the first user space task the kernel created. 1679 * 1680 * Return: 1 if the task structure is init. 0 otherwise. 1681 */ 1682 static inline int is_global_init(struct task_struct *tsk) 1683 { 1684 return task_tgid_nr(tsk) == 1; 1685 } 1686 1687 extern struct pid *cad_pid; 1688 1689 /* 1690 * Per process flags 1691 */ 1692 #define PF_VCPU 0x00000001 /* I'm a virtual CPU */ 1693 #define PF_IDLE 0x00000002 /* I am an IDLE thread */ 1694 #define PF_EXITING 0x00000004 /* Getting shut down */ 1695 #define PF_POSTCOREDUMP 0x00000008 /* Coredumps should ignore this task */ 1696 #define PF_IO_WORKER 0x00000010 /* Task is an IO worker */ 1697 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */ 1698 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */ 1699 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */ 1700 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */ 1701 #define PF_DUMPCORE 0x00000200 /* Dumped core */ 1702 #define PF_SIGNALED 0x00000400 /* Killed by a signal */ 1703 #define PF_MEMALLOC 0x00000800 /* Allocating memory */ 1704 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */ 1705 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */ 1706 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */ 1707 #define PF_FROZEN 0x00010000 /* Frozen for system suspend */ 1708 #define PF_KSWAPD 0x00020000 /* I am kswapd */ 1709 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocation requests will inherit GFP_NOFS */ 1710 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocation requests will inherit GFP_NOIO */ 1711 #define PF_LOCAL_THROTTLE 0x00100000 /* Throttle writes only against the bdi I write to, 1712 * I am cleaning dirty pages from some other bdi. */ 1713 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */ 1714 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */ 1715 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */ 1716 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */ 1717 #define PF_MEMALLOC_PIN 0x10000000 /* Allocation context constrained to zones which allow long term pinning. */ 1718 #define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezable */ 1719 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */ 1720 1721 /* 1722 * Only the _current_ task can read/write to tsk->flags, but other 1723 * tasks can access tsk->flags in readonly mode for example 1724 * with tsk_used_math (like during threaded core dumping). 1725 * There is however an exception to this rule during ptrace 1726 * or during fork: the ptracer task is allowed to write to the 1727 * child->flags of its traced child (same goes for fork, the parent 1728 * can write to the child->flags), because we're guaranteed the 1729 * child is not running and in turn not changing child->flags 1730 * at the same time the parent does it. 1731 */ 1732 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0) 1733 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0) 1734 #define clear_used_math() clear_stopped_child_used_math(current) 1735 #define set_used_math() set_stopped_child_used_math(current) 1736 1737 #define conditional_stopped_child_used_math(condition, child) \ 1738 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0) 1739 1740 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current) 1741 1742 #define copy_to_stopped_child_used_math(child) \ 1743 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0) 1744 1745 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */ 1746 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH) 1747 #define used_math() tsk_used_math(current) 1748 1749 static __always_inline bool is_percpu_thread(void) 1750 { 1751 #ifdef CONFIG_SMP 1752 return (current->flags & PF_NO_SETAFFINITY) && 1753 (current->nr_cpus_allowed == 1); 1754 #else 1755 return true; 1756 #endif 1757 } 1758 1759 /* Per-process atomic flags. */ 1760 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */ 1761 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */ 1762 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */ 1763 #define PFA_SPEC_SSB_DISABLE 3 /* Speculative Store Bypass disabled */ 1764 #define PFA_SPEC_SSB_FORCE_DISABLE 4 /* Speculative Store Bypass force disabled*/ 1765 #define PFA_SPEC_IB_DISABLE 5 /* Indirect branch speculation restricted */ 1766 #define PFA_SPEC_IB_FORCE_DISABLE 6 /* Indirect branch speculation permanently restricted */ 1767 #define PFA_SPEC_SSB_NOEXEC 7 /* Speculative Store Bypass clear on execve() */ 1768 1769 #define TASK_PFA_TEST(name, func) \ 1770 static inline bool task_##func(struct task_struct *p) \ 1771 { return test_bit(PFA_##name, &p->atomic_flags); } 1772 1773 #define TASK_PFA_SET(name, func) \ 1774 static inline void task_set_##func(struct task_struct *p) \ 1775 { set_bit(PFA_##name, &p->atomic_flags); } 1776 1777 #define TASK_PFA_CLEAR(name, func) \ 1778 static inline void task_clear_##func(struct task_struct *p) \ 1779 { clear_bit(PFA_##name, &p->atomic_flags); } 1780 1781 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs) 1782 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs) 1783 1784 TASK_PFA_TEST(SPREAD_PAGE, spread_page) 1785 TASK_PFA_SET(SPREAD_PAGE, spread_page) 1786 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page) 1787 1788 TASK_PFA_TEST(SPREAD_SLAB, spread_slab) 1789 TASK_PFA_SET(SPREAD_SLAB, spread_slab) 1790 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab) 1791 1792 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable) 1793 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable) 1794 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable) 1795 1796 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1797 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1798 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1799 1800 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1801 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1802 1803 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable) 1804 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable) 1805 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable) 1806 1807 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1808 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1809 1810 static inline void 1811 current_restore_flags(unsigned long orig_flags, unsigned long flags) 1812 { 1813 current->flags &= ~flags; 1814 current->flags |= orig_flags & flags; 1815 } 1816 1817 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial); 1818 extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed); 1819 #ifdef CONFIG_SMP 1820 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask); 1821 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask); 1822 extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node); 1823 extern void release_user_cpus_ptr(struct task_struct *p); 1824 extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask); 1825 extern void force_compatible_cpus_allowed_ptr(struct task_struct *p); 1826 extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p); 1827 #else 1828 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) 1829 { 1830 } 1831 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) 1832 { 1833 if (!cpumask_test_cpu(0, new_mask)) 1834 return -EINVAL; 1835 return 0; 1836 } 1837 static inline int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node) 1838 { 1839 if (src->user_cpus_ptr) 1840 return -EINVAL; 1841 return 0; 1842 } 1843 static inline void release_user_cpus_ptr(struct task_struct *p) 1844 { 1845 WARN_ON(p->user_cpus_ptr); 1846 } 1847 1848 static inline int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask) 1849 { 1850 return 0; 1851 } 1852 #endif 1853 1854 extern int yield_to(struct task_struct *p, bool preempt); 1855 extern void set_user_nice(struct task_struct *p, long nice); 1856 extern int task_prio(const struct task_struct *p); 1857 1858 /** 1859 * task_nice - return the nice value of a given task. 1860 * @p: the task in question. 1861 * 1862 * Return: The nice value [ -20 ... 0 ... 19 ]. 1863 */ 1864 static inline int task_nice(const struct task_struct *p) 1865 { 1866 return PRIO_TO_NICE((p)->static_prio); 1867 } 1868 1869 extern int can_nice(const struct task_struct *p, const int nice); 1870 extern int task_curr(const struct task_struct *p); 1871 extern int idle_cpu(int cpu); 1872 extern int available_idle_cpu(int cpu); 1873 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *); 1874 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *); 1875 extern void sched_set_fifo(struct task_struct *p); 1876 extern void sched_set_fifo_low(struct task_struct *p); 1877 extern void sched_set_normal(struct task_struct *p, int nice); 1878 extern int sched_setattr(struct task_struct *, const struct sched_attr *); 1879 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *); 1880 extern struct task_struct *idle_task(int cpu); 1881 1882 /** 1883 * is_idle_task - is the specified task an idle task? 1884 * @p: the task in question. 1885 * 1886 * Return: 1 if @p is an idle task. 0 otherwise. 1887 */ 1888 static __always_inline bool is_idle_task(const struct task_struct *p) 1889 { 1890 return !!(p->flags & PF_IDLE); 1891 } 1892 1893 extern struct task_struct *curr_task(int cpu); 1894 extern void ia64_set_curr_task(int cpu, struct task_struct *p); 1895 1896 void yield(void); 1897 1898 union thread_union { 1899 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK 1900 struct task_struct task; 1901 #endif 1902 #ifndef CONFIG_THREAD_INFO_IN_TASK 1903 struct thread_info thread_info; 1904 #endif 1905 unsigned long stack[THREAD_SIZE/sizeof(long)]; 1906 }; 1907 1908 #ifndef CONFIG_THREAD_INFO_IN_TASK 1909 extern struct thread_info init_thread_info; 1910 #endif 1911 1912 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)]; 1913 1914 #ifdef CONFIG_THREAD_INFO_IN_TASK 1915 # define task_thread_info(task) (&(task)->thread_info) 1916 #elif !defined(__HAVE_THREAD_FUNCTIONS) 1917 # define task_thread_info(task) ((struct thread_info *)(task)->stack) 1918 #endif 1919 1920 /* 1921 * find a task by one of its numerical ids 1922 * 1923 * find_task_by_pid_ns(): 1924 * finds a task by its pid in the specified namespace 1925 * find_task_by_vpid(): 1926 * finds a task by its virtual pid 1927 * 1928 * see also find_vpid() etc in include/linux/pid.h 1929 */ 1930 1931 extern struct task_struct *find_task_by_vpid(pid_t nr); 1932 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns); 1933 1934 /* 1935 * find a task by its virtual pid and get the task struct 1936 */ 1937 extern struct task_struct *find_get_task_by_vpid(pid_t nr); 1938 1939 extern int wake_up_state(struct task_struct *tsk, unsigned int state); 1940 extern int wake_up_process(struct task_struct *tsk); 1941 extern void wake_up_new_task(struct task_struct *tsk); 1942 1943 #ifdef CONFIG_SMP 1944 extern void kick_process(struct task_struct *tsk); 1945 #else 1946 static inline void kick_process(struct task_struct *tsk) { } 1947 #endif 1948 1949 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec); 1950 1951 static inline void set_task_comm(struct task_struct *tsk, const char *from) 1952 { 1953 __set_task_comm(tsk, from, false); 1954 } 1955 1956 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk); 1957 #define get_task_comm(buf, tsk) ({ \ 1958 BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN); \ 1959 __get_task_comm(buf, sizeof(buf), tsk); \ 1960 }) 1961 1962 #ifdef CONFIG_SMP 1963 static __always_inline void scheduler_ipi(void) 1964 { 1965 /* 1966 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting 1967 * TIF_NEED_RESCHED remotely (for the first time) will also send 1968 * this IPI. 1969 */ 1970 preempt_fold_need_resched(); 1971 } 1972 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state); 1973 #else 1974 static inline void scheduler_ipi(void) { } 1975 static inline unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state) 1976 { 1977 return 1; 1978 } 1979 #endif 1980 1981 /* 1982 * Set thread flags in other task's structures. 1983 * See asm/thread_info.h for TIF_xxxx flags available: 1984 */ 1985 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag) 1986 { 1987 set_ti_thread_flag(task_thread_info(tsk), flag); 1988 } 1989 1990 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag) 1991 { 1992 clear_ti_thread_flag(task_thread_info(tsk), flag); 1993 } 1994 1995 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag, 1996 bool value) 1997 { 1998 update_ti_thread_flag(task_thread_info(tsk), flag, value); 1999 } 2000 2001 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag) 2002 { 2003 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag); 2004 } 2005 2006 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag) 2007 { 2008 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag); 2009 } 2010 2011 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag) 2012 { 2013 return test_ti_thread_flag(task_thread_info(tsk), flag); 2014 } 2015 2016 static inline void set_tsk_need_resched(struct task_struct *tsk) 2017 { 2018 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 2019 } 2020 2021 static inline void clear_tsk_need_resched(struct task_struct *tsk) 2022 { 2023 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 2024 } 2025 2026 static inline int test_tsk_need_resched(struct task_struct *tsk) 2027 { 2028 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED)); 2029 } 2030 2031 /* 2032 * cond_resched() and cond_resched_lock(): latency reduction via 2033 * explicit rescheduling in places that are safe. The return 2034 * value indicates whether a reschedule was done in fact. 2035 * cond_resched_lock() will drop the spinlock before scheduling, 2036 */ 2037 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) 2038 extern int __cond_resched(void); 2039 2040 #if defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL) 2041 2042 DECLARE_STATIC_CALL(cond_resched, __cond_resched); 2043 2044 static __always_inline int _cond_resched(void) 2045 { 2046 return static_call_mod(cond_resched)(); 2047 } 2048 2049 #elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY) 2050 extern int dynamic_cond_resched(void); 2051 2052 static __always_inline int _cond_resched(void) 2053 { 2054 return dynamic_cond_resched(); 2055 } 2056 2057 #else 2058 2059 static inline int _cond_resched(void) 2060 { 2061 return __cond_resched(); 2062 } 2063 2064 #endif /* CONFIG_PREEMPT_DYNAMIC */ 2065 2066 #else 2067 2068 static inline int _cond_resched(void) { return 0; } 2069 2070 #endif /* !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) */ 2071 2072 #define cond_resched() ({ \ 2073 __might_resched(__FILE__, __LINE__, 0); \ 2074 _cond_resched(); \ 2075 }) 2076 2077 extern int __cond_resched_lock(spinlock_t *lock); 2078 extern int __cond_resched_rwlock_read(rwlock_t *lock); 2079 extern int __cond_resched_rwlock_write(rwlock_t *lock); 2080 2081 #define MIGHT_RESCHED_RCU_SHIFT 8 2082 #define MIGHT_RESCHED_PREEMPT_MASK ((1U << MIGHT_RESCHED_RCU_SHIFT) - 1) 2083 2084 #ifndef CONFIG_PREEMPT_RT 2085 /* 2086 * Non RT kernels have an elevated preempt count due to the held lock, 2087 * but are not allowed to be inside a RCU read side critical section 2088 */ 2089 # define PREEMPT_LOCK_RESCHED_OFFSETS PREEMPT_LOCK_OFFSET 2090 #else 2091 /* 2092 * spin/rw_lock() on RT implies rcu_read_lock(). The might_sleep() check in 2093 * cond_resched*lock() has to take that into account because it checks for 2094 * preempt_count() and rcu_preempt_depth(). 2095 */ 2096 # define PREEMPT_LOCK_RESCHED_OFFSETS \ 2097 (PREEMPT_LOCK_OFFSET + (1U << MIGHT_RESCHED_RCU_SHIFT)) 2098 #endif 2099 2100 #define cond_resched_lock(lock) ({ \ 2101 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2102 __cond_resched_lock(lock); \ 2103 }) 2104 2105 #define cond_resched_rwlock_read(lock) ({ \ 2106 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2107 __cond_resched_rwlock_read(lock); \ 2108 }) 2109 2110 #define cond_resched_rwlock_write(lock) ({ \ 2111 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2112 __cond_resched_rwlock_write(lock); \ 2113 }) 2114 2115 static inline void cond_resched_rcu(void) 2116 { 2117 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU) 2118 rcu_read_unlock(); 2119 cond_resched(); 2120 rcu_read_lock(); 2121 #endif 2122 } 2123 2124 #ifdef CONFIG_PREEMPT_DYNAMIC 2125 2126 extern bool preempt_model_none(void); 2127 extern bool preempt_model_voluntary(void); 2128 extern bool preempt_model_full(void); 2129 2130 #else 2131 2132 static inline bool preempt_model_none(void) 2133 { 2134 return IS_ENABLED(CONFIG_PREEMPT_NONE); 2135 } 2136 static inline bool preempt_model_voluntary(void) 2137 { 2138 return IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY); 2139 } 2140 static inline bool preempt_model_full(void) 2141 { 2142 return IS_ENABLED(CONFIG_PREEMPT); 2143 } 2144 2145 #endif 2146 2147 static inline bool preempt_model_rt(void) 2148 { 2149 return IS_ENABLED(CONFIG_PREEMPT_RT); 2150 } 2151 2152 /* 2153 * Does the preemption model allow non-cooperative preemption? 2154 * 2155 * For !CONFIG_PREEMPT_DYNAMIC kernels this is an exact match with 2156 * CONFIG_PREEMPTION; for CONFIG_PREEMPT_DYNAMIC this doesn't work as the 2157 * kernel is *built* with CONFIG_PREEMPTION=y but may run with e.g. the 2158 * PREEMPT_NONE model. 2159 */ 2160 static inline bool preempt_model_preemptible(void) 2161 { 2162 return preempt_model_full() || preempt_model_rt(); 2163 } 2164 2165 /* 2166 * Does a critical section need to be broken due to another 2167 * task waiting?: (technically does not depend on CONFIG_PREEMPTION, 2168 * but a general need for low latency) 2169 */ 2170 static inline int spin_needbreak(spinlock_t *lock) 2171 { 2172 #ifdef CONFIG_PREEMPTION 2173 return spin_is_contended(lock); 2174 #else 2175 return 0; 2176 #endif 2177 } 2178 2179 /* 2180 * Check if a rwlock is contended. 2181 * Returns non-zero if there is another task waiting on the rwlock. 2182 * Returns zero if the lock is not contended or the system / underlying 2183 * rwlock implementation does not support contention detection. 2184 * Technically does not depend on CONFIG_PREEMPTION, but a general need 2185 * for low latency. 2186 */ 2187 static inline int rwlock_needbreak(rwlock_t *lock) 2188 { 2189 #ifdef CONFIG_PREEMPTION 2190 return rwlock_is_contended(lock); 2191 #else 2192 return 0; 2193 #endif 2194 } 2195 2196 static __always_inline bool need_resched(void) 2197 { 2198 return unlikely(tif_need_resched()); 2199 } 2200 2201 /* 2202 * Wrappers for p->thread_info->cpu access. No-op on UP. 2203 */ 2204 #ifdef CONFIG_SMP 2205 2206 static inline unsigned int task_cpu(const struct task_struct *p) 2207 { 2208 return READ_ONCE(task_thread_info(p)->cpu); 2209 } 2210 2211 extern void set_task_cpu(struct task_struct *p, unsigned int cpu); 2212 2213 #else 2214 2215 static inline unsigned int task_cpu(const struct task_struct *p) 2216 { 2217 return 0; 2218 } 2219 2220 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu) 2221 { 2222 } 2223 2224 #endif /* CONFIG_SMP */ 2225 2226 extern bool sched_task_on_rq(struct task_struct *p); 2227 extern unsigned long get_wchan(struct task_struct *p); 2228 2229 /* 2230 * In order to reduce various lock holder preemption latencies provide an 2231 * interface to see if a vCPU is currently running or not. 2232 * 2233 * This allows us to terminate optimistic spin loops and block, analogous to 2234 * the native optimistic spin heuristic of testing if the lock owner task is 2235 * running or not. 2236 */ 2237 #ifndef vcpu_is_preempted 2238 static inline bool vcpu_is_preempted(int cpu) 2239 { 2240 return false; 2241 } 2242 #endif 2243 2244 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask); 2245 extern long sched_getaffinity(pid_t pid, struct cpumask *mask); 2246 2247 #ifndef TASK_SIZE_OF 2248 #define TASK_SIZE_OF(tsk) TASK_SIZE 2249 #endif 2250 2251 #ifdef CONFIG_SMP 2252 static inline bool owner_on_cpu(struct task_struct *owner) 2253 { 2254 /* 2255 * As lock holder preemption issue, we both skip spinning if 2256 * task is not on cpu or its cpu is preempted 2257 */ 2258 return READ_ONCE(owner->on_cpu) && !vcpu_is_preempted(task_cpu(owner)); 2259 } 2260 2261 /* Returns effective CPU energy utilization, as seen by the scheduler */ 2262 unsigned long sched_cpu_util(int cpu, unsigned long max); 2263 #endif /* CONFIG_SMP */ 2264 2265 #ifdef CONFIG_RSEQ 2266 2267 /* 2268 * Map the event mask on the user-space ABI enum rseq_cs_flags 2269 * for direct mask checks. 2270 */ 2271 enum rseq_event_mask_bits { 2272 RSEQ_EVENT_PREEMPT_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT, 2273 RSEQ_EVENT_SIGNAL_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT, 2274 RSEQ_EVENT_MIGRATE_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT, 2275 }; 2276 2277 enum rseq_event_mask { 2278 RSEQ_EVENT_PREEMPT = (1U << RSEQ_EVENT_PREEMPT_BIT), 2279 RSEQ_EVENT_SIGNAL = (1U << RSEQ_EVENT_SIGNAL_BIT), 2280 RSEQ_EVENT_MIGRATE = (1U << RSEQ_EVENT_MIGRATE_BIT), 2281 }; 2282 2283 static inline void rseq_set_notify_resume(struct task_struct *t) 2284 { 2285 if (t->rseq) 2286 set_tsk_thread_flag(t, TIF_NOTIFY_RESUME); 2287 } 2288 2289 void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs); 2290 2291 static inline void rseq_handle_notify_resume(struct ksignal *ksig, 2292 struct pt_regs *regs) 2293 { 2294 if (current->rseq) 2295 __rseq_handle_notify_resume(ksig, regs); 2296 } 2297 2298 static inline void rseq_signal_deliver(struct ksignal *ksig, 2299 struct pt_regs *regs) 2300 { 2301 preempt_disable(); 2302 __set_bit(RSEQ_EVENT_SIGNAL_BIT, ¤t->rseq_event_mask); 2303 preempt_enable(); 2304 rseq_handle_notify_resume(ksig, regs); 2305 } 2306 2307 /* rseq_preempt() requires preemption to be disabled. */ 2308 static inline void rseq_preempt(struct task_struct *t) 2309 { 2310 __set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask); 2311 rseq_set_notify_resume(t); 2312 } 2313 2314 /* rseq_migrate() requires preemption to be disabled. */ 2315 static inline void rseq_migrate(struct task_struct *t) 2316 { 2317 __set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask); 2318 rseq_set_notify_resume(t); 2319 } 2320 2321 /* 2322 * If parent process has a registered restartable sequences area, the 2323 * child inherits. Unregister rseq for a clone with CLONE_VM set. 2324 */ 2325 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags) 2326 { 2327 if (clone_flags & CLONE_VM) { 2328 t->rseq = NULL; 2329 t->rseq_sig = 0; 2330 t->rseq_event_mask = 0; 2331 } else { 2332 t->rseq = current->rseq; 2333 t->rseq_sig = current->rseq_sig; 2334 t->rseq_event_mask = current->rseq_event_mask; 2335 } 2336 } 2337 2338 static inline void rseq_execve(struct task_struct *t) 2339 { 2340 t->rseq = NULL; 2341 t->rseq_sig = 0; 2342 t->rseq_event_mask = 0; 2343 } 2344 2345 #else 2346 2347 static inline void rseq_set_notify_resume(struct task_struct *t) 2348 { 2349 } 2350 static inline void rseq_handle_notify_resume(struct ksignal *ksig, 2351 struct pt_regs *regs) 2352 { 2353 } 2354 static inline void rseq_signal_deliver(struct ksignal *ksig, 2355 struct pt_regs *regs) 2356 { 2357 } 2358 static inline void rseq_preempt(struct task_struct *t) 2359 { 2360 } 2361 static inline void rseq_migrate(struct task_struct *t) 2362 { 2363 } 2364 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags) 2365 { 2366 } 2367 static inline void rseq_execve(struct task_struct *t) 2368 { 2369 } 2370 2371 #endif 2372 2373 #ifdef CONFIG_DEBUG_RSEQ 2374 2375 void rseq_syscall(struct pt_regs *regs); 2376 2377 #else 2378 2379 static inline void rseq_syscall(struct pt_regs *regs) 2380 { 2381 } 2382 2383 #endif 2384 2385 #ifdef CONFIG_SCHED_CORE 2386 extern void sched_core_free(struct task_struct *tsk); 2387 extern void sched_core_fork(struct task_struct *p); 2388 extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type, 2389 unsigned long uaddr); 2390 #else 2391 static inline void sched_core_free(struct task_struct *tsk) { } 2392 static inline void sched_core_fork(struct task_struct *p) { } 2393 #endif 2394 2395 extern void sched_set_stop_task(int cpu, struct task_struct *stop); 2396 2397 #endif 2398