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