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 0x0000 85 #define TASK_INTERRUPTIBLE 0x0001 86 #define TASK_UNINTERRUPTIBLE 0x0002 87 #define __TASK_STOPPED 0x0004 88 #define __TASK_TRACED 0x0008 89 /* Used in tsk->exit_state: */ 90 #define EXIT_DEAD 0x0010 91 #define EXIT_ZOMBIE 0x0020 92 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD) 93 /* Used in tsk->state again: */ 94 #define TASK_PARKED 0x0040 95 #define TASK_DEAD 0x0080 96 #define TASK_WAKEKILL 0x0100 97 #define TASK_WAKING 0x0200 98 #define TASK_NOLOAD 0x0400 99 #define TASK_NEW 0x0800 100 /* RT specific auxilliary flag to mark RT lock waiters */ 101 #define TASK_RTLOCK_WAIT 0x1000 102 #define TASK_STATE_MAX 0x2000 103 104 /* Convenience macros for the sake of set_current_state: */ 105 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE) 106 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED) 107 #define TASK_TRACED __TASK_TRACED 108 109 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD) 110 111 /* Convenience macros for the sake of wake_up(): */ 112 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE) 113 114 /* get_task_state(): */ 115 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \ 116 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \ 117 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \ 118 TASK_PARKED) 119 120 #define task_is_running(task) (READ_ONCE((task)->__state) == TASK_RUNNING) 121 122 #define task_is_traced(task) ((READ_ONCE(task->jobctl) & JOBCTL_TRACED) != 0) 123 #define task_is_stopped(task) ((READ_ONCE(task->jobctl) & JOBCTL_STOPPED) != 0) 124 #define task_is_stopped_or_traced(task) ((READ_ONCE(task->jobctl) & (JOBCTL_STOPPED | JOBCTL_TRACED)) != 0) 125 126 /* 127 * Special states are those that do not use the normal wait-loop pattern. See 128 * the comment with set_special_state(). 129 */ 130 #define is_special_task_state(state) \ 131 ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD)) 132 133 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 134 # define debug_normal_state_change(state_value) \ 135 do { \ 136 WARN_ON_ONCE(is_special_task_state(state_value)); \ 137 current->task_state_change = _THIS_IP_; \ 138 } while (0) 139 140 # define debug_special_state_change(state_value) \ 141 do { \ 142 WARN_ON_ONCE(!is_special_task_state(state_value)); \ 143 current->task_state_change = _THIS_IP_; \ 144 } while (0) 145 146 # define debug_rtlock_wait_set_state() \ 147 do { \ 148 current->saved_state_change = current->task_state_change;\ 149 current->task_state_change = _THIS_IP_; \ 150 } while (0) 151 152 # define debug_rtlock_wait_restore_state() \ 153 do { \ 154 current->task_state_change = current->saved_state_change;\ 155 } while (0) 156 157 #else 158 # define debug_normal_state_change(cond) do { } while (0) 159 # define debug_special_state_change(cond) do { } while (0) 160 # define debug_rtlock_wait_set_state() do { } while (0) 161 # define debug_rtlock_wait_restore_state() do { } while (0) 162 #endif 163 164 /* 165 * set_current_state() includes a barrier so that the write of current->state 166 * is correctly serialised wrt the caller's subsequent test of whether to 167 * actually sleep: 168 * 169 * for (;;) { 170 * set_current_state(TASK_UNINTERRUPTIBLE); 171 * if (CONDITION) 172 * break; 173 * 174 * schedule(); 175 * } 176 * __set_current_state(TASK_RUNNING); 177 * 178 * If the caller does not need such serialisation (because, for instance, the 179 * CONDITION test and condition change and wakeup are under the same lock) then 180 * use __set_current_state(). 181 * 182 * The above is typically ordered against the wakeup, which does: 183 * 184 * CONDITION = 1; 185 * wake_up_state(p, TASK_UNINTERRUPTIBLE); 186 * 187 * where wake_up_state()/try_to_wake_up() executes a full memory barrier before 188 * accessing p->state. 189 * 190 * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is, 191 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a 192 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING). 193 * 194 * However, with slightly different timing the wakeup TASK_RUNNING store can 195 * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not 196 * a problem either because that will result in one extra go around the loop 197 * and our @cond test will save the day. 198 * 199 * Also see the comments of try_to_wake_up(). 200 */ 201 #define __set_current_state(state_value) \ 202 do { \ 203 debug_normal_state_change((state_value)); \ 204 WRITE_ONCE(current->__state, (state_value)); \ 205 } while (0) 206 207 #define set_current_state(state_value) \ 208 do { \ 209 debug_normal_state_change((state_value)); \ 210 smp_store_mb(current->__state, (state_value)); \ 211 } while (0) 212 213 /* 214 * set_special_state() should be used for those states when the blocking task 215 * can not use the regular condition based wait-loop. In that case we must 216 * serialize against wakeups such that any possible in-flight TASK_RUNNING 217 * stores will not collide with our state change. 218 */ 219 #define set_special_state(state_value) \ 220 do { \ 221 unsigned long flags; /* may shadow */ \ 222 \ 223 raw_spin_lock_irqsave(¤t->pi_lock, flags); \ 224 debug_special_state_change((state_value)); \ 225 WRITE_ONCE(current->__state, (state_value)); \ 226 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \ 227 } while (0) 228 229 /* 230 * PREEMPT_RT specific variants for "sleeping" spin/rwlocks 231 * 232 * RT's spin/rwlock substitutions are state preserving. The state of the 233 * task when blocking on the lock is saved in task_struct::saved_state and 234 * restored after the lock has been acquired. These operations are 235 * serialized by task_struct::pi_lock against try_to_wake_up(). Any non RT 236 * lock related wakeups while the task is blocked on the lock are 237 * redirected to operate on task_struct::saved_state to ensure that these 238 * are not dropped. On restore task_struct::saved_state is set to 239 * TASK_RUNNING so any wakeup attempt redirected to saved_state will fail. 240 * 241 * The lock operation looks like this: 242 * 243 * current_save_and_set_rtlock_wait_state(); 244 * for (;;) { 245 * if (try_lock()) 246 * break; 247 * raw_spin_unlock_irq(&lock->wait_lock); 248 * schedule_rtlock(); 249 * raw_spin_lock_irq(&lock->wait_lock); 250 * set_current_state(TASK_RTLOCK_WAIT); 251 * } 252 * current_restore_rtlock_saved_state(); 253 */ 254 #define current_save_and_set_rtlock_wait_state() \ 255 do { \ 256 lockdep_assert_irqs_disabled(); \ 257 raw_spin_lock(¤t->pi_lock); \ 258 current->saved_state = current->__state; \ 259 debug_rtlock_wait_set_state(); \ 260 WRITE_ONCE(current->__state, TASK_RTLOCK_WAIT); \ 261 raw_spin_unlock(¤t->pi_lock); \ 262 } while (0); 263 264 #define current_restore_rtlock_saved_state() \ 265 do { \ 266 lockdep_assert_irqs_disabled(); \ 267 raw_spin_lock(¤t->pi_lock); \ 268 debug_rtlock_wait_restore_state(); \ 269 WRITE_ONCE(current->__state, current->saved_state); \ 270 current->saved_state = TASK_RUNNING; \ 271 raw_spin_unlock(¤t->pi_lock); \ 272 } while (0); 273 274 #define get_current_state() READ_ONCE(current->__state) 275 276 /* 277 * Define the task command name length as enum, then it can be visible to 278 * BPF programs. 279 */ 280 enum { 281 TASK_COMM_LEN = 16, 282 }; 283 284 extern void scheduler_tick(void); 285 286 #define MAX_SCHEDULE_TIMEOUT LONG_MAX 287 288 extern long schedule_timeout(long timeout); 289 extern long schedule_timeout_interruptible(long timeout); 290 extern long schedule_timeout_killable(long timeout); 291 extern long schedule_timeout_uninterruptible(long timeout); 292 extern long schedule_timeout_idle(long timeout); 293 asmlinkage void schedule(void); 294 extern void schedule_preempt_disabled(void); 295 asmlinkage void preempt_schedule_irq(void); 296 #ifdef CONFIG_PREEMPT_RT 297 extern void schedule_rtlock(void); 298 #endif 299 300 extern int __must_check io_schedule_prepare(void); 301 extern void io_schedule_finish(int token); 302 extern long io_schedule_timeout(long timeout); 303 extern void io_schedule(void); 304 305 /** 306 * struct prev_cputime - snapshot of system and user cputime 307 * @utime: time spent in user mode 308 * @stime: time spent in system mode 309 * @lock: protects the above two fields 310 * 311 * Stores previous user/system time values such that we can guarantee 312 * monotonicity. 313 */ 314 struct prev_cputime { 315 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE 316 u64 utime; 317 u64 stime; 318 raw_spinlock_t lock; 319 #endif 320 }; 321 322 enum vtime_state { 323 /* Task is sleeping or running in a CPU with VTIME inactive: */ 324 VTIME_INACTIVE = 0, 325 /* Task is idle */ 326 VTIME_IDLE, 327 /* Task runs in kernelspace in a CPU with VTIME active: */ 328 VTIME_SYS, 329 /* Task runs in userspace in a CPU with VTIME active: */ 330 VTIME_USER, 331 /* Task runs as guests in a CPU with VTIME active: */ 332 VTIME_GUEST, 333 }; 334 335 struct vtime { 336 seqcount_t seqcount; 337 unsigned long long starttime; 338 enum vtime_state state; 339 unsigned int cpu; 340 u64 utime; 341 u64 stime; 342 u64 gtime; 343 }; 344 345 /* 346 * Utilization clamp constraints. 347 * @UCLAMP_MIN: Minimum utilization 348 * @UCLAMP_MAX: Maximum utilization 349 * @UCLAMP_CNT: Utilization clamp constraints count 350 */ 351 enum uclamp_id { 352 UCLAMP_MIN = 0, 353 UCLAMP_MAX, 354 UCLAMP_CNT 355 }; 356 357 #ifdef CONFIG_SMP 358 extern struct root_domain def_root_domain; 359 extern struct mutex sched_domains_mutex; 360 #endif 361 362 struct sched_info { 363 #ifdef CONFIG_SCHED_INFO 364 /* Cumulative counters: */ 365 366 /* # of times we have run on this CPU: */ 367 unsigned long pcount; 368 369 /* Time spent waiting on a runqueue: */ 370 unsigned long long run_delay; 371 372 /* Timestamps: */ 373 374 /* When did we last run on a CPU? */ 375 unsigned long long last_arrival; 376 377 /* When were we last queued to run? */ 378 unsigned long long last_queued; 379 380 #endif /* CONFIG_SCHED_INFO */ 381 }; 382 383 /* 384 * Integer metrics need fixed point arithmetic, e.g., sched/fair 385 * has a few: load, load_avg, util_avg, freq, and capacity. 386 * 387 * We define a basic fixed point arithmetic range, and then formalize 388 * all these metrics based on that basic range. 389 */ 390 # define SCHED_FIXEDPOINT_SHIFT 10 391 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT) 392 393 /* Increase resolution of cpu_capacity calculations */ 394 # define SCHED_CAPACITY_SHIFT SCHED_FIXEDPOINT_SHIFT 395 # define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT) 396 397 struct load_weight { 398 unsigned long weight; 399 u32 inv_weight; 400 }; 401 402 /** 403 * struct util_est - Estimation utilization of FAIR tasks 404 * @enqueued: instantaneous estimated utilization of a task/cpu 405 * @ewma: the Exponential Weighted Moving Average (EWMA) 406 * utilization of a task 407 * 408 * Support data structure to track an Exponential Weighted Moving Average 409 * (EWMA) of a FAIR task's utilization. New samples are added to the moving 410 * average each time a task completes an activation. Sample's weight is chosen 411 * so that the EWMA will be relatively insensitive to transient changes to the 412 * task's workload. 413 * 414 * The enqueued attribute has a slightly different meaning for tasks and cpus: 415 * - task: the task's util_avg at last task dequeue time 416 * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU 417 * Thus, the util_est.enqueued of a task represents the contribution on the 418 * estimated utilization of the CPU where that task is currently enqueued. 419 * 420 * Only for tasks we track a moving average of the past instantaneous 421 * estimated utilization. This allows to absorb sporadic drops in utilization 422 * of an otherwise almost periodic task. 423 * 424 * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg 425 * updates. When a task is dequeued, its util_est should not be updated if its 426 * util_avg has not been updated in the meantime. 427 * This information is mapped into the MSB bit of util_est.enqueued at dequeue 428 * time. Since max value of util_est.enqueued for a task is 1024 (PELT util_avg 429 * for a task) it is safe to use MSB. 430 */ 431 struct util_est { 432 unsigned int enqueued; 433 unsigned int ewma; 434 #define UTIL_EST_WEIGHT_SHIFT 2 435 #define UTIL_AVG_UNCHANGED 0x80000000 436 } __attribute__((__aligned__(sizeof(u64)))); 437 438 /* 439 * The load/runnable/util_avg accumulates an infinite geometric series 440 * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c). 441 * 442 * [load_avg definition] 443 * 444 * load_avg = runnable% * scale_load_down(load) 445 * 446 * [runnable_avg definition] 447 * 448 * runnable_avg = runnable% * SCHED_CAPACITY_SCALE 449 * 450 * [util_avg definition] 451 * 452 * util_avg = running% * SCHED_CAPACITY_SCALE 453 * 454 * where runnable% is the time ratio that a sched_entity is runnable and 455 * running% the time ratio that a sched_entity is running. 456 * 457 * For cfs_rq, they are the aggregated values of all runnable and blocked 458 * sched_entities. 459 * 460 * The load/runnable/util_avg doesn't directly factor frequency scaling and CPU 461 * capacity scaling. The scaling is done through the rq_clock_pelt that is used 462 * for computing those signals (see update_rq_clock_pelt()) 463 * 464 * N.B., the above ratios (runnable% and running%) themselves are in the 465 * range of [0, 1]. To do fixed point arithmetics, we therefore scale them 466 * to as large a range as necessary. This is for example reflected by 467 * util_avg's SCHED_CAPACITY_SCALE. 468 * 469 * [Overflow issue] 470 * 471 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities 472 * with the highest load (=88761), always runnable on a single cfs_rq, 473 * and should not overflow as the number already hits PID_MAX_LIMIT. 474 * 475 * For all other cases (including 32-bit kernels), struct load_weight's 476 * weight will overflow first before we do, because: 477 * 478 * Max(load_avg) <= Max(load.weight) 479 * 480 * Then it is the load_weight's responsibility to consider overflow 481 * issues. 482 */ 483 struct sched_avg { 484 u64 last_update_time; 485 u64 load_sum; 486 u64 runnable_sum; 487 u32 util_sum; 488 u32 period_contrib; 489 unsigned long load_avg; 490 unsigned long runnable_avg; 491 unsigned long util_avg; 492 struct util_est util_est; 493 } ____cacheline_aligned; 494 495 struct sched_statistics { 496 #ifdef CONFIG_SCHEDSTATS 497 u64 wait_start; 498 u64 wait_max; 499 u64 wait_count; 500 u64 wait_sum; 501 u64 iowait_count; 502 u64 iowait_sum; 503 504 u64 sleep_start; 505 u64 sleep_max; 506 s64 sum_sleep_runtime; 507 508 u64 block_start; 509 u64 block_max; 510 s64 sum_block_runtime; 511 512 u64 exec_max; 513 u64 slice_max; 514 515 u64 nr_migrations_cold; 516 u64 nr_failed_migrations_affine; 517 u64 nr_failed_migrations_running; 518 u64 nr_failed_migrations_hot; 519 u64 nr_forced_migrations; 520 521 u64 nr_wakeups; 522 u64 nr_wakeups_sync; 523 u64 nr_wakeups_migrate; 524 u64 nr_wakeups_local; 525 u64 nr_wakeups_remote; 526 u64 nr_wakeups_affine; 527 u64 nr_wakeups_affine_attempts; 528 u64 nr_wakeups_passive; 529 u64 nr_wakeups_idle; 530 531 #ifdef CONFIG_SCHED_CORE 532 u64 core_forceidle_sum; 533 #endif 534 #endif /* CONFIG_SCHEDSTATS */ 535 } ____cacheline_aligned; 536 537 struct sched_entity { 538 /* For load-balancing: */ 539 struct load_weight load; 540 struct rb_node run_node; 541 struct list_head group_node; 542 unsigned int on_rq; 543 544 u64 exec_start; 545 u64 sum_exec_runtime; 546 u64 vruntime; 547 u64 prev_sum_exec_runtime; 548 549 u64 nr_migrations; 550 551 #ifdef CONFIG_FAIR_GROUP_SCHED 552 int depth; 553 struct sched_entity *parent; 554 /* rq on which this entity is (to be) queued: */ 555 struct cfs_rq *cfs_rq; 556 /* rq "owned" by this entity/group: */ 557 struct cfs_rq *my_q; 558 /* cached value of my_q->h_nr_running */ 559 unsigned long runnable_weight; 560 #endif 561 562 #ifdef CONFIG_SMP 563 /* 564 * Per entity load average tracking. 565 * 566 * Put into separate cache line so it does not 567 * collide with read-mostly values above. 568 */ 569 struct sched_avg avg; 570 #endif 571 }; 572 573 struct sched_rt_entity { 574 struct list_head run_list; 575 unsigned long timeout; 576 unsigned long watchdog_stamp; 577 unsigned int time_slice; 578 unsigned short on_rq; 579 unsigned short on_list; 580 581 struct sched_rt_entity *back; 582 #ifdef CONFIG_RT_GROUP_SCHED 583 struct sched_rt_entity *parent; 584 /* rq on which this entity is (to be) queued: */ 585 struct rt_rq *rt_rq; 586 /* rq "owned" by this entity/group: */ 587 struct rt_rq *my_q; 588 #endif 589 } __randomize_layout; 590 591 struct sched_dl_entity { 592 struct rb_node rb_node; 593 594 /* 595 * Original scheduling parameters. Copied here from sched_attr 596 * during sched_setattr(), they will remain the same until 597 * the next sched_setattr(). 598 */ 599 u64 dl_runtime; /* Maximum runtime for each instance */ 600 u64 dl_deadline; /* Relative deadline of each instance */ 601 u64 dl_period; /* Separation of two instances (period) */ 602 u64 dl_bw; /* dl_runtime / dl_period */ 603 u64 dl_density; /* dl_runtime / dl_deadline */ 604 605 /* 606 * Actual scheduling parameters. Initialized with the values above, 607 * they are continuously updated during task execution. Note that 608 * the remaining runtime could be < 0 in case we are in overrun. 609 */ 610 s64 runtime; /* Remaining runtime for this instance */ 611 u64 deadline; /* Absolute deadline for this instance */ 612 unsigned int flags; /* Specifying the scheduler behaviour */ 613 614 /* 615 * Some bool flags: 616 * 617 * @dl_throttled tells if we exhausted the runtime. If so, the 618 * task has to wait for a replenishment to be performed at the 619 * next firing of dl_timer. 620 * 621 * @dl_yielded tells if task gave up the CPU before consuming 622 * all its available runtime during the last job. 623 * 624 * @dl_non_contending tells if the task is inactive while still 625 * contributing to the active utilization. In other words, it 626 * indicates if the inactive timer has been armed and its handler 627 * has not been executed yet. This flag is useful to avoid race 628 * conditions between the inactive timer handler and the wakeup 629 * code. 630 * 631 * @dl_overrun tells if the task asked to be informed about runtime 632 * overruns. 633 */ 634 unsigned int dl_throttled : 1; 635 unsigned int dl_yielded : 1; 636 unsigned int dl_non_contending : 1; 637 unsigned int dl_overrun : 1; 638 639 /* 640 * Bandwidth enforcement timer. Each -deadline task has its 641 * own bandwidth to be enforced, thus we need one timer per task. 642 */ 643 struct hrtimer dl_timer; 644 645 /* 646 * Inactive timer, responsible for decreasing the active utilization 647 * at the "0-lag time". When a -deadline task blocks, it contributes 648 * to GRUB's active utilization until the "0-lag time", hence a 649 * timer is needed to decrease the active utilization at the correct 650 * time. 651 */ 652 struct hrtimer inactive_timer; 653 654 #ifdef CONFIG_RT_MUTEXES 655 /* 656 * Priority Inheritance. When a DEADLINE scheduling entity is boosted 657 * pi_se points to the donor, otherwise points to the dl_se it belongs 658 * to (the original one/itself). 659 */ 660 struct sched_dl_entity *pi_se; 661 #endif 662 }; 663 664 #ifdef CONFIG_UCLAMP_TASK 665 /* Number of utilization clamp buckets (shorter alias) */ 666 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT 667 668 /* 669 * Utilization clamp for a scheduling entity 670 * @value: clamp value "assigned" to a se 671 * @bucket_id: bucket index corresponding to the "assigned" value 672 * @active: the se is currently refcounted in a rq's bucket 673 * @user_defined: the requested clamp value comes from user-space 674 * 675 * The bucket_id is the index of the clamp bucket matching the clamp value 676 * which is pre-computed and stored to avoid expensive integer divisions from 677 * the fast path. 678 * 679 * The active bit is set whenever a task has got an "effective" value assigned, 680 * which can be different from the clamp value "requested" from user-space. 681 * This allows to know a task is refcounted in the rq's bucket corresponding 682 * to the "effective" bucket_id. 683 * 684 * The user_defined bit is set whenever a task has got a task-specific clamp 685 * value requested from userspace, i.e. the system defaults apply to this task 686 * just as a restriction. This allows to relax default clamps when a less 687 * restrictive task-specific value has been requested, thus allowing to 688 * implement a "nice" semantic. For example, a task running with a 20% 689 * default boost can still drop its own boosting to 0%. 690 */ 691 struct uclamp_se { 692 unsigned int value : bits_per(SCHED_CAPACITY_SCALE); 693 unsigned int bucket_id : bits_per(UCLAMP_BUCKETS); 694 unsigned int active : 1; 695 unsigned int user_defined : 1; 696 }; 697 #endif /* CONFIG_UCLAMP_TASK */ 698 699 union rcu_special { 700 struct { 701 u8 blocked; 702 u8 need_qs; 703 u8 exp_hint; /* Hint for performance. */ 704 u8 need_mb; /* Readers need smp_mb(). */ 705 } b; /* Bits. */ 706 u32 s; /* Set of bits. */ 707 }; 708 709 enum perf_event_task_context { 710 perf_invalid_context = -1, 711 perf_hw_context = 0, 712 perf_sw_context, 713 perf_nr_task_contexts, 714 }; 715 716 struct wake_q_node { 717 struct wake_q_node *next; 718 }; 719 720 struct kmap_ctrl { 721 #ifdef CONFIG_KMAP_LOCAL 722 int idx; 723 pte_t pteval[KM_MAX_IDX]; 724 #endif 725 }; 726 727 struct task_struct { 728 #ifdef CONFIG_THREAD_INFO_IN_TASK 729 /* 730 * For reasons of header soup (see current_thread_info()), this 731 * must be the first element of task_struct. 732 */ 733 struct thread_info thread_info; 734 #endif 735 unsigned int __state; 736 737 #ifdef CONFIG_PREEMPT_RT 738 /* saved state for "spinlock sleepers" */ 739 unsigned int saved_state; 740 #endif 741 742 /* 743 * This begins the randomizable portion of task_struct. Only 744 * scheduling-critical items should be added above here. 745 */ 746 randomized_struct_fields_start 747 748 void *stack; 749 refcount_t usage; 750 /* Per task flags (PF_*), defined further below: */ 751 unsigned int flags; 752 unsigned int ptrace; 753 754 #ifdef CONFIG_SMP 755 int on_cpu; 756 struct __call_single_node wake_entry; 757 unsigned int wakee_flips; 758 unsigned long wakee_flip_decay_ts; 759 struct task_struct *last_wakee; 760 761 /* 762 * recent_used_cpu is initially set as the last CPU used by a task 763 * that wakes affine another task. Waker/wakee relationships can 764 * push tasks around a CPU where each wakeup moves to the next one. 765 * Tracking a recently used CPU allows a quick search for a recently 766 * used CPU that may be idle. 767 */ 768 int recent_used_cpu; 769 int wake_cpu; 770 #endif 771 int on_rq; 772 773 int prio; 774 int static_prio; 775 int normal_prio; 776 unsigned int rt_priority; 777 778 struct sched_entity se; 779 struct sched_rt_entity rt; 780 struct sched_dl_entity dl; 781 const struct sched_class *sched_class; 782 783 #ifdef CONFIG_SCHED_CORE 784 struct rb_node core_node; 785 unsigned long core_cookie; 786 unsigned int core_occupation; 787 #endif 788 789 #ifdef CONFIG_CGROUP_SCHED 790 struct task_group *sched_task_group; 791 #endif 792 793 #ifdef CONFIG_UCLAMP_TASK 794 /* 795 * Clamp values requested for a scheduling entity. 796 * Must be updated with task_rq_lock() held. 797 */ 798 struct uclamp_se uclamp_req[UCLAMP_CNT]; 799 /* 800 * Effective clamp values used for a scheduling entity. 801 * Must be updated with task_rq_lock() held. 802 */ 803 struct uclamp_se uclamp[UCLAMP_CNT]; 804 #endif 805 806 struct sched_statistics stats; 807 808 #ifdef CONFIG_PREEMPT_NOTIFIERS 809 /* List of struct preempt_notifier: */ 810 struct hlist_head preempt_notifiers; 811 #endif 812 813 #ifdef CONFIG_BLK_DEV_IO_TRACE 814 unsigned int btrace_seq; 815 #endif 816 817 unsigned int policy; 818 int nr_cpus_allowed; 819 const cpumask_t *cpus_ptr; 820 cpumask_t *user_cpus_ptr; 821 cpumask_t cpus_mask; 822 void *migration_pending; 823 #ifdef CONFIG_SMP 824 unsigned short migration_disabled; 825 #endif 826 unsigned short migration_flags; 827 828 #ifdef CONFIG_PREEMPT_RCU 829 int rcu_read_lock_nesting; 830 union rcu_special rcu_read_unlock_special; 831 struct list_head rcu_node_entry; 832 struct rcu_node *rcu_blocked_node; 833 #endif /* #ifdef CONFIG_PREEMPT_RCU */ 834 835 #ifdef CONFIG_TASKS_RCU 836 unsigned long rcu_tasks_nvcsw; 837 u8 rcu_tasks_holdout; 838 u8 rcu_tasks_idx; 839 int rcu_tasks_idle_cpu; 840 struct list_head rcu_tasks_holdout_list; 841 #endif /* #ifdef CONFIG_TASKS_RCU */ 842 843 #ifdef CONFIG_TASKS_TRACE_RCU 844 int trc_reader_nesting; 845 int trc_ipi_to_cpu; 846 union rcu_special trc_reader_special; 847 struct list_head trc_holdout_list; 848 struct list_head trc_blkd_node; 849 int trc_blkd_cpu; 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 #ifdef CONFIG_RV 1506 /* 1507 * Per-task RV monitor. Nowadays fixed in RV_PER_TASK_MONITORS. 1508 * If we find justification for more monitors, we can think 1509 * about adding more or developing a dynamic method. So far, 1510 * none of these are justified. 1511 */ 1512 union rv_task_monitor rv[RV_PER_TASK_MONITORS]; 1513 #endif 1514 1515 /* 1516 * New fields for task_struct should be added above here, so that 1517 * they are included in the randomized portion of task_struct. 1518 */ 1519 randomized_struct_fields_end 1520 1521 /* CPU-specific state of this task: */ 1522 struct thread_struct thread; 1523 1524 /* 1525 * WARNING: on x86, 'thread_struct' contains a variable-sized 1526 * structure. It *MUST* be at the end of 'task_struct'. 1527 * 1528 * Do not put anything below here! 1529 */ 1530 }; 1531 1532 static inline struct pid *task_pid(struct task_struct *task) 1533 { 1534 return task->thread_pid; 1535 } 1536 1537 /* 1538 * the helpers to get the task's different pids as they are seen 1539 * from various namespaces 1540 * 1541 * task_xid_nr() : global id, i.e. the id seen from the init namespace; 1542 * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of 1543 * current. 1544 * task_xid_nr_ns() : id seen from the ns specified; 1545 * 1546 * see also pid_nr() etc in include/linux/pid.h 1547 */ 1548 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns); 1549 1550 static inline pid_t task_pid_nr(struct task_struct *tsk) 1551 { 1552 return tsk->pid; 1553 } 1554 1555 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1556 { 1557 return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns); 1558 } 1559 1560 static inline pid_t task_pid_vnr(struct task_struct *tsk) 1561 { 1562 return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL); 1563 } 1564 1565 1566 static inline pid_t task_tgid_nr(struct task_struct *tsk) 1567 { 1568 return tsk->tgid; 1569 } 1570 1571 /** 1572 * pid_alive - check that a task structure is not stale 1573 * @p: Task structure to be checked. 1574 * 1575 * Test if a process is not yet dead (at most zombie state) 1576 * If pid_alive fails, then pointers within the task structure 1577 * can be stale and must not be dereferenced. 1578 * 1579 * Return: 1 if the process is alive. 0 otherwise. 1580 */ 1581 static inline int pid_alive(const struct task_struct *p) 1582 { 1583 return p->thread_pid != NULL; 1584 } 1585 1586 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1587 { 1588 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns); 1589 } 1590 1591 static inline pid_t task_pgrp_vnr(struct task_struct *tsk) 1592 { 1593 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL); 1594 } 1595 1596 1597 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1598 { 1599 return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns); 1600 } 1601 1602 static inline pid_t task_session_vnr(struct task_struct *tsk) 1603 { 1604 return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL); 1605 } 1606 1607 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1608 { 1609 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, ns); 1610 } 1611 1612 static inline pid_t task_tgid_vnr(struct task_struct *tsk) 1613 { 1614 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, NULL); 1615 } 1616 1617 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns) 1618 { 1619 pid_t pid = 0; 1620 1621 rcu_read_lock(); 1622 if (pid_alive(tsk)) 1623 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns); 1624 rcu_read_unlock(); 1625 1626 return pid; 1627 } 1628 1629 static inline pid_t task_ppid_nr(const struct task_struct *tsk) 1630 { 1631 return task_ppid_nr_ns(tsk, &init_pid_ns); 1632 } 1633 1634 /* Obsolete, do not use: */ 1635 static inline pid_t task_pgrp_nr(struct task_struct *tsk) 1636 { 1637 return task_pgrp_nr_ns(tsk, &init_pid_ns); 1638 } 1639 1640 #define TASK_REPORT_IDLE (TASK_REPORT + 1) 1641 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1) 1642 1643 static inline unsigned int __task_state_index(unsigned int tsk_state, 1644 unsigned int tsk_exit_state) 1645 { 1646 unsigned int state = (tsk_state | tsk_exit_state) & TASK_REPORT; 1647 1648 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX); 1649 1650 if (tsk_state == TASK_IDLE) 1651 state = TASK_REPORT_IDLE; 1652 1653 /* 1654 * We're lying here, but rather than expose a completely new task state 1655 * to userspace, we can make this appear as if the task has gone through 1656 * a regular rt_mutex_lock() call. 1657 */ 1658 if (tsk_state == TASK_RTLOCK_WAIT) 1659 state = TASK_UNINTERRUPTIBLE; 1660 1661 return fls(state); 1662 } 1663 1664 static inline unsigned int task_state_index(struct task_struct *tsk) 1665 { 1666 return __task_state_index(READ_ONCE(tsk->__state), tsk->exit_state); 1667 } 1668 1669 static inline char task_index_to_char(unsigned int state) 1670 { 1671 static const char state_char[] = "RSDTtXZPI"; 1672 1673 BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1); 1674 1675 return state_char[state]; 1676 } 1677 1678 static inline char task_state_to_char(struct task_struct *tsk) 1679 { 1680 return task_index_to_char(task_state_index(tsk)); 1681 } 1682 1683 /** 1684 * is_global_init - check if a task structure is init. Since init 1685 * is free to have sub-threads we need to check tgid. 1686 * @tsk: Task structure to be checked. 1687 * 1688 * Check if a task structure is the first user space task the kernel created. 1689 * 1690 * Return: 1 if the task structure is init. 0 otherwise. 1691 */ 1692 static inline int is_global_init(struct task_struct *tsk) 1693 { 1694 return task_tgid_nr(tsk) == 1; 1695 } 1696 1697 extern struct pid *cad_pid; 1698 1699 /* 1700 * Per process flags 1701 */ 1702 #define PF_VCPU 0x00000001 /* I'm a virtual CPU */ 1703 #define PF_IDLE 0x00000002 /* I am an IDLE thread */ 1704 #define PF_EXITING 0x00000004 /* Getting shut down */ 1705 #define PF_POSTCOREDUMP 0x00000008 /* Coredumps should ignore this task */ 1706 #define PF_IO_WORKER 0x00000010 /* Task is an IO worker */ 1707 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */ 1708 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */ 1709 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */ 1710 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */ 1711 #define PF_DUMPCORE 0x00000200 /* Dumped core */ 1712 #define PF_SIGNALED 0x00000400 /* Killed by a signal */ 1713 #define PF_MEMALLOC 0x00000800 /* Allocating memory */ 1714 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */ 1715 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */ 1716 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */ 1717 #define PF_FROZEN 0x00010000 /* Frozen for system suspend */ 1718 #define PF_KSWAPD 0x00020000 /* I am kswapd */ 1719 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocation requests will inherit GFP_NOFS */ 1720 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocation requests will inherit GFP_NOIO */ 1721 #define PF_LOCAL_THROTTLE 0x00100000 /* Throttle writes only against the bdi I write to, 1722 * I am cleaning dirty pages from some other bdi. */ 1723 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */ 1724 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */ 1725 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */ 1726 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */ 1727 #define PF_MEMALLOC_PIN 0x10000000 /* Allocation context constrained to zones which allow long term pinning. */ 1728 #define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezable */ 1729 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */ 1730 1731 /* 1732 * Only the _current_ task can read/write to tsk->flags, but other 1733 * tasks can access tsk->flags in readonly mode for example 1734 * with tsk_used_math (like during threaded core dumping). 1735 * There is however an exception to this rule during ptrace 1736 * or during fork: the ptracer task is allowed to write to the 1737 * child->flags of its traced child (same goes for fork, the parent 1738 * can write to the child->flags), because we're guaranteed the 1739 * child is not running and in turn not changing child->flags 1740 * at the same time the parent does it. 1741 */ 1742 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0) 1743 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0) 1744 #define clear_used_math() clear_stopped_child_used_math(current) 1745 #define set_used_math() set_stopped_child_used_math(current) 1746 1747 #define conditional_stopped_child_used_math(condition, child) \ 1748 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0) 1749 1750 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current) 1751 1752 #define copy_to_stopped_child_used_math(child) \ 1753 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0) 1754 1755 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */ 1756 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH) 1757 #define used_math() tsk_used_math(current) 1758 1759 static __always_inline bool is_percpu_thread(void) 1760 { 1761 #ifdef CONFIG_SMP 1762 return (current->flags & PF_NO_SETAFFINITY) && 1763 (current->nr_cpus_allowed == 1); 1764 #else 1765 return true; 1766 #endif 1767 } 1768 1769 /* Per-process atomic flags. */ 1770 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */ 1771 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */ 1772 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */ 1773 #define PFA_SPEC_SSB_DISABLE 3 /* Speculative Store Bypass disabled */ 1774 #define PFA_SPEC_SSB_FORCE_DISABLE 4 /* Speculative Store Bypass force disabled*/ 1775 #define PFA_SPEC_IB_DISABLE 5 /* Indirect branch speculation restricted */ 1776 #define PFA_SPEC_IB_FORCE_DISABLE 6 /* Indirect branch speculation permanently restricted */ 1777 #define PFA_SPEC_SSB_NOEXEC 7 /* Speculative Store Bypass clear on execve() */ 1778 1779 #define TASK_PFA_TEST(name, func) \ 1780 static inline bool task_##func(struct task_struct *p) \ 1781 { return test_bit(PFA_##name, &p->atomic_flags); } 1782 1783 #define TASK_PFA_SET(name, func) \ 1784 static inline void task_set_##func(struct task_struct *p) \ 1785 { set_bit(PFA_##name, &p->atomic_flags); } 1786 1787 #define TASK_PFA_CLEAR(name, func) \ 1788 static inline void task_clear_##func(struct task_struct *p) \ 1789 { clear_bit(PFA_##name, &p->atomic_flags); } 1790 1791 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs) 1792 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs) 1793 1794 TASK_PFA_TEST(SPREAD_PAGE, spread_page) 1795 TASK_PFA_SET(SPREAD_PAGE, spread_page) 1796 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page) 1797 1798 TASK_PFA_TEST(SPREAD_SLAB, spread_slab) 1799 TASK_PFA_SET(SPREAD_SLAB, spread_slab) 1800 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab) 1801 1802 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable) 1803 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable) 1804 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable) 1805 1806 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1807 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1808 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec) 1809 1810 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1811 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1812 1813 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable) 1814 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable) 1815 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable) 1816 1817 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1818 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable) 1819 1820 static inline void 1821 current_restore_flags(unsigned long orig_flags, unsigned long flags) 1822 { 1823 current->flags &= ~flags; 1824 current->flags |= orig_flags & flags; 1825 } 1826 1827 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial); 1828 extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_effective_cpus); 1829 #ifdef CONFIG_SMP 1830 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask); 1831 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask); 1832 extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node); 1833 extern void release_user_cpus_ptr(struct task_struct *p); 1834 extern int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask); 1835 extern void force_compatible_cpus_allowed_ptr(struct task_struct *p); 1836 extern void relax_compatible_cpus_allowed_ptr(struct task_struct *p); 1837 #else 1838 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) 1839 { 1840 } 1841 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) 1842 { 1843 if (!cpumask_test_cpu(0, new_mask)) 1844 return -EINVAL; 1845 return 0; 1846 } 1847 static inline int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node) 1848 { 1849 if (src->user_cpus_ptr) 1850 return -EINVAL; 1851 return 0; 1852 } 1853 static inline void release_user_cpus_ptr(struct task_struct *p) 1854 { 1855 WARN_ON(p->user_cpus_ptr); 1856 } 1857 1858 static inline int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask) 1859 { 1860 return 0; 1861 } 1862 #endif 1863 1864 extern int yield_to(struct task_struct *p, bool preempt); 1865 extern void set_user_nice(struct task_struct *p, long nice); 1866 extern int task_prio(const struct task_struct *p); 1867 1868 /** 1869 * task_nice - return the nice value of a given task. 1870 * @p: the task in question. 1871 * 1872 * Return: The nice value [ -20 ... 0 ... 19 ]. 1873 */ 1874 static inline int task_nice(const struct task_struct *p) 1875 { 1876 return PRIO_TO_NICE((p)->static_prio); 1877 } 1878 1879 extern int can_nice(const struct task_struct *p, const int nice); 1880 extern int task_curr(const struct task_struct *p); 1881 extern int idle_cpu(int cpu); 1882 extern int available_idle_cpu(int cpu); 1883 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *); 1884 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *); 1885 extern void sched_set_fifo(struct task_struct *p); 1886 extern void sched_set_fifo_low(struct task_struct *p); 1887 extern void sched_set_normal(struct task_struct *p, int nice); 1888 extern int sched_setattr(struct task_struct *, const struct sched_attr *); 1889 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *); 1890 extern struct task_struct *idle_task(int cpu); 1891 1892 /** 1893 * is_idle_task - is the specified task an idle task? 1894 * @p: the task in question. 1895 * 1896 * Return: 1 if @p is an idle task. 0 otherwise. 1897 */ 1898 static __always_inline bool is_idle_task(const struct task_struct *p) 1899 { 1900 return !!(p->flags & PF_IDLE); 1901 } 1902 1903 extern struct task_struct *curr_task(int cpu); 1904 extern void ia64_set_curr_task(int cpu, struct task_struct *p); 1905 1906 void yield(void); 1907 1908 union thread_union { 1909 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK 1910 struct task_struct task; 1911 #endif 1912 #ifndef CONFIG_THREAD_INFO_IN_TASK 1913 struct thread_info thread_info; 1914 #endif 1915 unsigned long stack[THREAD_SIZE/sizeof(long)]; 1916 }; 1917 1918 #ifndef CONFIG_THREAD_INFO_IN_TASK 1919 extern struct thread_info init_thread_info; 1920 #endif 1921 1922 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)]; 1923 1924 #ifdef CONFIG_THREAD_INFO_IN_TASK 1925 # define task_thread_info(task) (&(task)->thread_info) 1926 #elif !defined(__HAVE_THREAD_FUNCTIONS) 1927 # define task_thread_info(task) ((struct thread_info *)(task)->stack) 1928 #endif 1929 1930 /* 1931 * find a task by one of its numerical ids 1932 * 1933 * find_task_by_pid_ns(): 1934 * finds a task by its pid in the specified namespace 1935 * find_task_by_vpid(): 1936 * finds a task by its virtual pid 1937 * 1938 * see also find_vpid() etc in include/linux/pid.h 1939 */ 1940 1941 extern struct task_struct *find_task_by_vpid(pid_t nr); 1942 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns); 1943 1944 /* 1945 * find a task by its virtual pid and get the task struct 1946 */ 1947 extern struct task_struct *find_get_task_by_vpid(pid_t nr); 1948 1949 extern int wake_up_state(struct task_struct *tsk, unsigned int state); 1950 extern int wake_up_process(struct task_struct *tsk); 1951 extern void wake_up_new_task(struct task_struct *tsk); 1952 1953 #ifdef CONFIG_SMP 1954 extern void kick_process(struct task_struct *tsk); 1955 #else 1956 static inline void kick_process(struct task_struct *tsk) { } 1957 #endif 1958 1959 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec); 1960 1961 static inline void set_task_comm(struct task_struct *tsk, const char *from) 1962 { 1963 __set_task_comm(tsk, from, false); 1964 } 1965 1966 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk); 1967 #define get_task_comm(buf, tsk) ({ \ 1968 BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN); \ 1969 __get_task_comm(buf, sizeof(buf), tsk); \ 1970 }) 1971 1972 #ifdef CONFIG_SMP 1973 static __always_inline void scheduler_ipi(void) 1974 { 1975 /* 1976 * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting 1977 * TIF_NEED_RESCHED remotely (for the first time) will also send 1978 * this IPI. 1979 */ 1980 preempt_fold_need_resched(); 1981 } 1982 extern unsigned long wait_task_inactive(struct task_struct *, unsigned int match_state); 1983 #else 1984 static inline void scheduler_ipi(void) { } 1985 static inline unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state) 1986 { 1987 return 1; 1988 } 1989 #endif 1990 1991 /* 1992 * Set thread flags in other task's structures. 1993 * See asm/thread_info.h for TIF_xxxx flags available: 1994 */ 1995 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag) 1996 { 1997 set_ti_thread_flag(task_thread_info(tsk), flag); 1998 } 1999 2000 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag) 2001 { 2002 clear_ti_thread_flag(task_thread_info(tsk), flag); 2003 } 2004 2005 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag, 2006 bool value) 2007 { 2008 update_ti_thread_flag(task_thread_info(tsk), flag, value); 2009 } 2010 2011 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag) 2012 { 2013 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag); 2014 } 2015 2016 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag) 2017 { 2018 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag); 2019 } 2020 2021 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag) 2022 { 2023 return test_ti_thread_flag(task_thread_info(tsk), flag); 2024 } 2025 2026 static inline void set_tsk_need_resched(struct task_struct *tsk) 2027 { 2028 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 2029 } 2030 2031 static inline void clear_tsk_need_resched(struct task_struct *tsk) 2032 { 2033 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 2034 } 2035 2036 static inline int test_tsk_need_resched(struct task_struct *tsk) 2037 { 2038 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED)); 2039 } 2040 2041 /* 2042 * cond_resched() and cond_resched_lock(): latency reduction via 2043 * explicit rescheduling in places that are safe. The return 2044 * value indicates whether a reschedule was done in fact. 2045 * cond_resched_lock() will drop the spinlock before scheduling, 2046 */ 2047 #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) 2048 extern int __cond_resched(void); 2049 2050 #if defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL) 2051 2052 DECLARE_STATIC_CALL(cond_resched, __cond_resched); 2053 2054 static __always_inline int _cond_resched(void) 2055 { 2056 return static_call_mod(cond_resched)(); 2057 } 2058 2059 #elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY) 2060 extern int dynamic_cond_resched(void); 2061 2062 static __always_inline int _cond_resched(void) 2063 { 2064 return dynamic_cond_resched(); 2065 } 2066 2067 #else 2068 2069 static inline int _cond_resched(void) 2070 { 2071 return __cond_resched(); 2072 } 2073 2074 #endif /* CONFIG_PREEMPT_DYNAMIC */ 2075 2076 #else 2077 2078 static inline int _cond_resched(void) { return 0; } 2079 2080 #endif /* !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) */ 2081 2082 #define cond_resched() ({ \ 2083 __might_resched(__FILE__, __LINE__, 0); \ 2084 _cond_resched(); \ 2085 }) 2086 2087 extern int __cond_resched_lock(spinlock_t *lock); 2088 extern int __cond_resched_rwlock_read(rwlock_t *lock); 2089 extern int __cond_resched_rwlock_write(rwlock_t *lock); 2090 2091 #define MIGHT_RESCHED_RCU_SHIFT 8 2092 #define MIGHT_RESCHED_PREEMPT_MASK ((1U << MIGHT_RESCHED_RCU_SHIFT) - 1) 2093 2094 #ifndef CONFIG_PREEMPT_RT 2095 /* 2096 * Non RT kernels have an elevated preempt count due to the held lock, 2097 * but are not allowed to be inside a RCU read side critical section 2098 */ 2099 # define PREEMPT_LOCK_RESCHED_OFFSETS PREEMPT_LOCK_OFFSET 2100 #else 2101 /* 2102 * spin/rw_lock() on RT implies rcu_read_lock(). The might_sleep() check in 2103 * cond_resched*lock() has to take that into account because it checks for 2104 * preempt_count() and rcu_preempt_depth(). 2105 */ 2106 # define PREEMPT_LOCK_RESCHED_OFFSETS \ 2107 (PREEMPT_LOCK_OFFSET + (1U << MIGHT_RESCHED_RCU_SHIFT)) 2108 #endif 2109 2110 #define cond_resched_lock(lock) ({ \ 2111 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2112 __cond_resched_lock(lock); \ 2113 }) 2114 2115 #define cond_resched_rwlock_read(lock) ({ \ 2116 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2117 __cond_resched_rwlock_read(lock); \ 2118 }) 2119 2120 #define cond_resched_rwlock_write(lock) ({ \ 2121 __might_resched(__FILE__, __LINE__, PREEMPT_LOCK_RESCHED_OFFSETS); \ 2122 __cond_resched_rwlock_write(lock); \ 2123 }) 2124 2125 static inline void cond_resched_rcu(void) 2126 { 2127 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU) 2128 rcu_read_unlock(); 2129 cond_resched(); 2130 rcu_read_lock(); 2131 #endif 2132 } 2133 2134 #ifdef CONFIG_PREEMPT_DYNAMIC 2135 2136 extern bool preempt_model_none(void); 2137 extern bool preempt_model_voluntary(void); 2138 extern bool preempt_model_full(void); 2139 2140 #else 2141 2142 static inline bool preempt_model_none(void) 2143 { 2144 return IS_ENABLED(CONFIG_PREEMPT_NONE); 2145 } 2146 static inline bool preempt_model_voluntary(void) 2147 { 2148 return IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY); 2149 } 2150 static inline bool preempt_model_full(void) 2151 { 2152 return IS_ENABLED(CONFIG_PREEMPT); 2153 } 2154 2155 #endif 2156 2157 static inline bool preempt_model_rt(void) 2158 { 2159 return IS_ENABLED(CONFIG_PREEMPT_RT); 2160 } 2161 2162 /* 2163 * Does the preemption model allow non-cooperative preemption? 2164 * 2165 * For !CONFIG_PREEMPT_DYNAMIC kernels this is an exact match with 2166 * CONFIG_PREEMPTION; for CONFIG_PREEMPT_DYNAMIC this doesn't work as the 2167 * kernel is *built* with CONFIG_PREEMPTION=y but may run with e.g. the 2168 * PREEMPT_NONE model. 2169 */ 2170 static inline bool preempt_model_preemptible(void) 2171 { 2172 return preempt_model_full() || preempt_model_rt(); 2173 } 2174 2175 /* 2176 * Does a critical section need to be broken due to another 2177 * task waiting?: (technically does not depend on CONFIG_PREEMPTION, 2178 * but a general need for low latency) 2179 */ 2180 static inline int spin_needbreak(spinlock_t *lock) 2181 { 2182 #ifdef CONFIG_PREEMPTION 2183 return spin_is_contended(lock); 2184 #else 2185 return 0; 2186 #endif 2187 } 2188 2189 /* 2190 * Check if a rwlock is contended. 2191 * Returns non-zero if there is another task waiting on the rwlock. 2192 * Returns zero if the lock is not contended or the system / underlying 2193 * rwlock implementation does not support contention detection. 2194 * Technically does not depend on CONFIG_PREEMPTION, but a general need 2195 * for low latency. 2196 */ 2197 static inline int rwlock_needbreak(rwlock_t *lock) 2198 { 2199 #ifdef CONFIG_PREEMPTION 2200 return rwlock_is_contended(lock); 2201 #else 2202 return 0; 2203 #endif 2204 } 2205 2206 static __always_inline bool need_resched(void) 2207 { 2208 return unlikely(tif_need_resched()); 2209 } 2210 2211 /* 2212 * Wrappers for p->thread_info->cpu access. No-op on UP. 2213 */ 2214 #ifdef CONFIG_SMP 2215 2216 static inline unsigned int task_cpu(const struct task_struct *p) 2217 { 2218 return READ_ONCE(task_thread_info(p)->cpu); 2219 } 2220 2221 extern void set_task_cpu(struct task_struct *p, unsigned int cpu); 2222 2223 #else 2224 2225 static inline unsigned int task_cpu(const struct task_struct *p) 2226 { 2227 return 0; 2228 } 2229 2230 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu) 2231 { 2232 } 2233 2234 #endif /* CONFIG_SMP */ 2235 2236 extern bool sched_task_on_rq(struct task_struct *p); 2237 extern unsigned long get_wchan(struct task_struct *p); 2238 extern struct task_struct *cpu_curr_snapshot(int cpu); 2239 2240 /* 2241 * In order to reduce various lock holder preemption latencies provide an 2242 * interface to see if a vCPU is currently running or not. 2243 * 2244 * This allows us to terminate optimistic spin loops and block, analogous to 2245 * the native optimistic spin heuristic of testing if the lock owner task is 2246 * running or not. 2247 */ 2248 #ifndef vcpu_is_preempted 2249 static inline bool vcpu_is_preempted(int cpu) 2250 { 2251 return false; 2252 } 2253 #endif 2254 2255 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask); 2256 extern long sched_getaffinity(pid_t pid, struct cpumask *mask); 2257 2258 #ifndef TASK_SIZE_OF 2259 #define TASK_SIZE_OF(tsk) TASK_SIZE 2260 #endif 2261 2262 #ifdef CONFIG_SMP 2263 static inline bool owner_on_cpu(struct task_struct *owner) 2264 { 2265 /* 2266 * As lock holder preemption issue, we both skip spinning if 2267 * task is not on cpu or its cpu is preempted 2268 */ 2269 return READ_ONCE(owner->on_cpu) && !vcpu_is_preempted(task_cpu(owner)); 2270 } 2271 2272 /* Returns effective CPU energy utilization, as seen by the scheduler */ 2273 unsigned long sched_cpu_util(int cpu); 2274 #endif /* CONFIG_SMP */ 2275 2276 #ifdef CONFIG_RSEQ 2277 2278 /* 2279 * Map the event mask on the user-space ABI enum rseq_cs_flags 2280 * for direct mask checks. 2281 */ 2282 enum rseq_event_mask_bits { 2283 RSEQ_EVENT_PREEMPT_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT, 2284 RSEQ_EVENT_SIGNAL_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT, 2285 RSEQ_EVENT_MIGRATE_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT, 2286 }; 2287 2288 enum rseq_event_mask { 2289 RSEQ_EVENT_PREEMPT = (1U << RSEQ_EVENT_PREEMPT_BIT), 2290 RSEQ_EVENT_SIGNAL = (1U << RSEQ_EVENT_SIGNAL_BIT), 2291 RSEQ_EVENT_MIGRATE = (1U << RSEQ_EVENT_MIGRATE_BIT), 2292 }; 2293 2294 static inline void rseq_set_notify_resume(struct task_struct *t) 2295 { 2296 if (t->rseq) 2297 set_tsk_thread_flag(t, TIF_NOTIFY_RESUME); 2298 } 2299 2300 void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs); 2301 2302 static inline void rseq_handle_notify_resume(struct ksignal *ksig, 2303 struct pt_regs *regs) 2304 { 2305 if (current->rseq) 2306 __rseq_handle_notify_resume(ksig, regs); 2307 } 2308 2309 static inline void rseq_signal_deliver(struct ksignal *ksig, 2310 struct pt_regs *regs) 2311 { 2312 preempt_disable(); 2313 __set_bit(RSEQ_EVENT_SIGNAL_BIT, ¤t->rseq_event_mask); 2314 preempt_enable(); 2315 rseq_handle_notify_resume(ksig, regs); 2316 } 2317 2318 /* rseq_preempt() requires preemption to be disabled. */ 2319 static inline void rseq_preempt(struct task_struct *t) 2320 { 2321 __set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask); 2322 rseq_set_notify_resume(t); 2323 } 2324 2325 /* rseq_migrate() requires preemption to be disabled. */ 2326 static inline void rseq_migrate(struct task_struct *t) 2327 { 2328 __set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask); 2329 rseq_set_notify_resume(t); 2330 } 2331 2332 /* 2333 * If parent process has a registered restartable sequences area, the 2334 * child inherits. Unregister rseq for a clone with CLONE_VM set. 2335 */ 2336 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags) 2337 { 2338 if (clone_flags & CLONE_VM) { 2339 t->rseq = NULL; 2340 t->rseq_sig = 0; 2341 t->rseq_event_mask = 0; 2342 } else { 2343 t->rseq = current->rseq; 2344 t->rseq_sig = current->rseq_sig; 2345 t->rseq_event_mask = current->rseq_event_mask; 2346 } 2347 } 2348 2349 static inline void rseq_execve(struct task_struct *t) 2350 { 2351 t->rseq = NULL; 2352 t->rseq_sig = 0; 2353 t->rseq_event_mask = 0; 2354 } 2355 2356 #else 2357 2358 static inline void rseq_set_notify_resume(struct task_struct *t) 2359 { 2360 } 2361 static inline void rseq_handle_notify_resume(struct ksignal *ksig, 2362 struct pt_regs *regs) 2363 { 2364 } 2365 static inline void rseq_signal_deliver(struct ksignal *ksig, 2366 struct pt_regs *regs) 2367 { 2368 } 2369 static inline void rseq_preempt(struct task_struct *t) 2370 { 2371 } 2372 static inline void rseq_migrate(struct task_struct *t) 2373 { 2374 } 2375 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags) 2376 { 2377 } 2378 static inline void rseq_execve(struct task_struct *t) 2379 { 2380 } 2381 2382 #endif 2383 2384 #ifdef CONFIG_DEBUG_RSEQ 2385 2386 void rseq_syscall(struct pt_regs *regs); 2387 2388 #else 2389 2390 static inline void rseq_syscall(struct pt_regs *regs) 2391 { 2392 } 2393 2394 #endif 2395 2396 #ifdef CONFIG_SCHED_CORE 2397 extern void sched_core_free(struct task_struct *tsk); 2398 extern void sched_core_fork(struct task_struct *p); 2399 extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type, 2400 unsigned long uaddr); 2401 #else 2402 static inline void sched_core_free(struct task_struct *tsk) { } 2403 static inline void sched_core_fork(struct task_struct *p) { } 2404 #endif 2405 2406 extern void sched_set_stop_task(int cpu, struct task_struct *stop); 2407 2408 #endif 2409