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/kcov.h> 18 #include <linux/mutex.h> 19 #include <linux/plist.h> 20 #include <linux/hrtimer.h> 21 #include <linux/seccomp.h> 22 #include <linux/nodemask.h> 23 #include <linux/rcupdate.h> 24 #include <linux/resource.h> 25 #include <linux/latencytop.h> 26 #include <linux/sched/prio.h> 27 #include <linux/signal_types.h> 28 #include <linux/mm_types_task.h> 29 #include <linux/task_io_accounting.h> 30 31 /* task_struct member predeclarations (sorted alphabetically): */ 32 struct audit_context; 33 struct backing_dev_info; 34 struct bio_list; 35 struct blk_plug; 36 struct cfs_rq; 37 struct fs_struct; 38 struct futex_pi_state; 39 struct io_context; 40 struct mempolicy; 41 struct nameidata; 42 struct nsproxy; 43 struct perf_event_context; 44 struct pid_namespace; 45 struct pipe_inode_info; 46 struct rcu_node; 47 struct reclaim_state; 48 struct robust_list_head; 49 struct sched_attr; 50 struct sched_param; 51 struct seq_file; 52 struct sighand_struct; 53 struct signal_struct; 54 struct task_delay_info; 55 struct task_group; 56 57 /* 58 * Task state bitmask. NOTE! These bits are also 59 * encoded in fs/proc/array.c: get_task_state(). 60 * 61 * We have two separate sets of flags: task->state 62 * is about runnability, while task->exit_state are 63 * about the task exiting. Confusing, but this way 64 * modifying one set can't modify the other one by 65 * mistake. 66 */ 67 68 /* Used in tsk->state: */ 69 #define TASK_RUNNING 0x0000 70 #define TASK_INTERRUPTIBLE 0x0001 71 #define TASK_UNINTERRUPTIBLE 0x0002 72 #define __TASK_STOPPED 0x0004 73 #define __TASK_TRACED 0x0008 74 /* Used in tsk->exit_state: */ 75 #define EXIT_DEAD 0x0010 76 #define EXIT_ZOMBIE 0x0020 77 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD) 78 /* Used in tsk->state again: */ 79 #define TASK_PARKED 0x0040 80 #define TASK_DEAD 0x0080 81 #define TASK_WAKEKILL 0x0100 82 #define TASK_WAKING 0x0200 83 #define TASK_NOLOAD 0x0400 84 #define TASK_NEW 0x0800 85 #define TASK_STATE_MAX 0x1000 86 87 /* Convenience macros for the sake of set_current_state: */ 88 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE) 89 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED) 90 #define TASK_TRACED (TASK_WAKEKILL | __TASK_TRACED) 91 92 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD) 93 94 /* Convenience macros for the sake of wake_up(): */ 95 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE) 96 97 /* get_task_state(): */ 98 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \ 99 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \ 100 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \ 101 TASK_PARKED) 102 103 #define task_is_traced(task) ((task->state & __TASK_TRACED) != 0) 104 105 #define task_is_stopped(task) ((task->state & __TASK_STOPPED) != 0) 106 107 #define task_is_stopped_or_traced(task) ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0) 108 109 #define task_contributes_to_load(task) ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \ 110 (task->flags & PF_FROZEN) == 0 && \ 111 (task->state & TASK_NOLOAD) == 0) 112 113 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 114 115 /* 116 * Special states are those that do not use the normal wait-loop pattern. See 117 * the comment with set_special_state(). 118 */ 119 #define is_special_task_state(state) \ 120 ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_DEAD)) 121 122 #define __set_current_state(state_value) \ 123 do { \ 124 WARN_ON_ONCE(is_special_task_state(state_value));\ 125 current->task_state_change = _THIS_IP_; \ 126 current->state = (state_value); \ 127 } while (0) 128 129 #define set_current_state(state_value) \ 130 do { \ 131 WARN_ON_ONCE(is_special_task_state(state_value));\ 132 current->task_state_change = _THIS_IP_; \ 133 smp_store_mb(current->state, (state_value)); \ 134 } while (0) 135 136 #define set_special_state(state_value) \ 137 do { \ 138 unsigned long flags; /* may shadow */ \ 139 WARN_ON_ONCE(!is_special_task_state(state_value)); \ 140 raw_spin_lock_irqsave(¤t->pi_lock, flags); \ 141 current->task_state_change = _THIS_IP_; \ 142 current->state = (state_value); \ 143 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \ 144 } while (0) 145 #else 146 /* 147 * set_current_state() includes a barrier so that the write of current->state 148 * is correctly serialised wrt the caller's subsequent test of whether to 149 * actually sleep: 150 * 151 * for (;;) { 152 * set_current_state(TASK_UNINTERRUPTIBLE); 153 * if (!need_sleep) 154 * break; 155 * 156 * schedule(); 157 * } 158 * __set_current_state(TASK_RUNNING); 159 * 160 * If the caller does not need such serialisation (because, for instance, the 161 * condition test and condition change and wakeup are under the same lock) then 162 * use __set_current_state(). 163 * 164 * The above is typically ordered against the wakeup, which does: 165 * 166 * need_sleep = false; 167 * wake_up_state(p, TASK_UNINTERRUPTIBLE); 168 * 169 * Where wake_up_state() (and all other wakeup primitives) imply enough 170 * barriers to order the store of the variable against wakeup. 171 * 172 * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is, 173 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a 174 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING). 175 * 176 * However, with slightly different timing the wakeup TASK_RUNNING store can 177 * also collide with the TASK_UNINTERRUPTIBLE store. Loosing that store is not 178 * a problem either because that will result in one extra go around the loop 179 * and our @cond test will save the day. 180 * 181 * Also see the comments of try_to_wake_up(). 182 */ 183 #define __set_current_state(state_value) \ 184 current->state = (state_value) 185 186 #define set_current_state(state_value) \ 187 smp_store_mb(current->state, (state_value)) 188 189 /* 190 * set_special_state() should be used for those states when the blocking task 191 * can not use the regular condition based wait-loop. In that case we must 192 * serialize against wakeups such that any possible in-flight TASK_RUNNING stores 193 * will not collide with our state change. 194 */ 195 #define set_special_state(state_value) \ 196 do { \ 197 unsigned long flags; /* may shadow */ \ 198 raw_spin_lock_irqsave(¤t->pi_lock, flags); \ 199 current->state = (state_value); \ 200 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \ 201 } while (0) 202 203 #endif 204 205 /* Task command name length: */ 206 #define TASK_COMM_LEN 16 207 208 extern void scheduler_tick(void); 209 210 #define MAX_SCHEDULE_TIMEOUT LONG_MAX 211 212 extern long schedule_timeout(long timeout); 213 extern long schedule_timeout_interruptible(long timeout); 214 extern long schedule_timeout_killable(long timeout); 215 extern long schedule_timeout_uninterruptible(long timeout); 216 extern long schedule_timeout_idle(long timeout); 217 asmlinkage void schedule(void); 218 extern void schedule_preempt_disabled(void); 219 220 extern int __must_check io_schedule_prepare(void); 221 extern void io_schedule_finish(int token); 222 extern long io_schedule_timeout(long timeout); 223 extern void io_schedule(void); 224 225 /** 226 * struct prev_cputime - snapshot of system and user cputime 227 * @utime: time spent in user mode 228 * @stime: time spent in system mode 229 * @lock: protects the above two fields 230 * 231 * Stores previous user/system time values such that we can guarantee 232 * monotonicity. 233 */ 234 struct prev_cputime { 235 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE 236 u64 utime; 237 u64 stime; 238 raw_spinlock_t lock; 239 #endif 240 }; 241 242 /** 243 * struct task_cputime - collected CPU time counts 244 * @utime: time spent in user mode, in nanoseconds 245 * @stime: time spent in kernel mode, in nanoseconds 246 * @sum_exec_runtime: total time spent on the CPU, in nanoseconds 247 * 248 * This structure groups together three kinds of CPU time that are tracked for 249 * threads and thread groups. Most things considering CPU time want to group 250 * these counts together and treat all three of them in parallel. 251 */ 252 struct task_cputime { 253 u64 utime; 254 u64 stime; 255 unsigned long long sum_exec_runtime; 256 }; 257 258 /* Alternate field names when used on cache expirations: */ 259 #define virt_exp utime 260 #define prof_exp stime 261 #define sched_exp sum_exec_runtime 262 263 enum vtime_state { 264 /* Task is sleeping or running in a CPU with VTIME inactive: */ 265 VTIME_INACTIVE = 0, 266 /* Task runs in userspace in a CPU with VTIME active: */ 267 VTIME_USER, 268 /* Task runs in kernelspace in a CPU with VTIME active: */ 269 VTIME_SYS, 270 }; 271 272 struct vtime { 273 seqcount_t seqcount; 274 unsigned long long starttime; 275 enum vtime_state state; 276 u64 utime; 277 u64 stime; 278 u64 gtime; 279 }; 280 281 struct sched_info { 282 #ifdef CONFIG_SCHED_INFO 283 /* Cumulative counters: */ 284 285 /* # of times we have run on this CPU: */ 286 unsigned long pcount; 287 288 /* Time spent waiting on a runqueue: */ 289 unsigned long long run_delay; 290 291 /* Timestamps: */ 292 293 /* When did we last run on a CPU? */ 294 unsigned long long last_arrival; 295 296 /* When were we last queued to run? */ 297 unsigned long long last_queued; 298 299 #endif /* CONFIG_SCHED_INFO */ 300 }; 301 302 /* 303 * Integer metrics need fixed point arithmetic, e.g., sched/fair 304 * has a few: load, load_avg, util_avg, freq, and capacity. 305 * 306 * We define a basic fixed point arithmetic range, and then formalize 307 * all these metrics based on that basic range. 308 */ 309 # define SCHED_FIXEDPOINT_SHIFT 10 310 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT) 311 312 struct load_weight { 313 unsigned long weight; 314 u32 inv_weight; 315 }; 316 317 /** 318 * struct util_est - Estimation utilization of FAIR tasks 319 * @enqueued: instantaneous estimated utilization of a task/cpu 320 * @ewma: the Exponential Weighted Moving Average (EWMA) 321 * utilization of a task 322 * 323 * Support data structure to track an Exponential Weighted Moving Average 324 * (EWMA) of a FAIR task's utilization. New samples are added to the moving 325 * average each time a task completes an activation. Sample's weight is chosen 326 * so that the EWMA will be relatively insensitive to transient changes to the 327 * task's workload. 328 * 329 * The enqueued attribute has a slightly different meaning for tasks and cpus: 330 * - task: the task's util_avg at last task dequeue time 331 * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU 332 * Thus, the util_est.enqueued of a task represents the contribution on the 333 * estimated utilization of the CPU where that task is currently enqueued. 334 * 335 * Only for tasks we track a moving average of the past instantaneous 336 * estimated utilization. This allows to absorb sporadic drops in utilization 337 * of an otherwise almost periodic task. 338 */ 339 struct util_est { 340 unsigned int enqueued; 341 unsigned int ewma; 342 #define UTIL_EST_WEIGHT_SHIFT 2 343 } __attribute__((__aligned__(sizeof(u64)))); 344 345 /* 346 * The load_avg/util_avg accumulates an infinite geometric series 347 * (see __update_load_avg() in kernel/sched/fair.c). 348 * 349 * [load_avg definition] 350 * 351 * load_avg = runnable% * scale_load_down(load) 352 * 353 * where runnable% is the time ratio that a sched_entity is runnable. 354 * For cfs_rq, it is the aggregated load_avg of all runnable and 355 * blocked sched_entities. 356 * 357 * load_avg may also take frequency scaling into account: 358 * 359 * load_avg = runnable% * scale_load_down(load) * freq% 360 * 361 * where freq% is the CPU frequency normalized to the highest frequency. 362 * 363 * [util_avg definition] 364 * 365 * util_avg = running% * SCHED_CAPACITY_SCALE 366 * 367 * where running% is the time ratio that a sched_entity is running on 368 * a CPU. For cfs_rq, it is the aggregated util_avg of all runnable 369 * and blocked sched_entities. 370 * 371 * util_avg may also factor frequency scaling and CPU capacity scaling: 372 * 373 * util_avg = running% * SCHED_CAPACITY_SCALE * freq% * capacity% 374 * 375 * where freq% is the same as above, and capacity% is the CPU capacity 376 * normalized to the greatest capacity (due to uarch differences, etc). 377 * 378 * N.B., the above ratios (runnable%, running%, freq%, and capacity%) 379 * themselves are in the range of [0, 1]. To do fixed point arithmetics, 380 * we therefore scale them to as large a range as necessary. This is for 381 * example reflected by util_avg's SCHED_CAPACITY_SCALE. 382 * 383 * [Overflow issue] 384 * 385 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities 386 * with the highest load (=88761), always runnable on a single cfs_rq, 387 * and should not overflow as the number already hits PID_MAX_LIMIT. 388 * 389 * For all other cases (including 32-bit kernels), struct load_weight's 390 * weight will overflow first before we do, because: 391 * 392 * Max(load_avg) <= Max(load.weight) 393 * 394 * Then it is the load_weight's responsibility to consider overflow 395 * issues. 396 */ 397 struct sched_avg { 398 u64 last_update_time; 399 u64 load_sum; 400 u64 runnable_load_sum; 401 u32 util_sum; 402 u32 period_contrib; 403 unsigned long load_avg; 404 unsigned long runnable_load_avg; 405 unsigned long util_avg; 406 struct util_est util_est; 407 } ____cacheline_aligned; 408 409 struct sched_statistics { 410 #ifdef CONFIG_SCHEDSTATS 411 u64 wait_start; 412 u64 wait_max; 413 u64 wait_count; 414 u64 wait_sum; 415 u64 iowait_count; 416 u64 iowait_sum; 417 418 u64 sleep_start; 419 u64 sleep_max; 420 s64 sum_sleep_runtime; 421 422 u64 block_start; 423 u64 block_max; 424 u64 exec_max; 425 u64 slice_max; 426 427 u64 nr_migrations_cold; 428 u64 nr_failed_migrations_affine; 429 u64 nr_failed_migrations_running; 430 u64 nr_failed_migrations_hot; 431 u64 nr_forced_migrations; 432 433 u64 nr_wakeups; 434 u64 nr_wakeups_sync; 435 u64 nr_wakeups_migrate; 436 u64 nr_wakeups_local; 437 u64 nr_wakeups_remote; 438 u64 nr_wakeups_affine; 439 u64 nr_wakeups_affine_attempts; 440 u64 nr_wakeups_passive; 441 u64 nr_wakeups_idle; 442 #endif 443 }; 444 445 struct sched_entity { 446 /* For load-balancing: */ 447 struct load_weight load; 448 unsigned long runnable_weight; 449 struct rb_node run_node; 450 struct list_head group_node; 451 unsigned int on_rq; 452 453 u64 exec_start; 454 u64 sum_exec_runtime; 455 u64 vruntime; 456 u64 prev_sum_exec_runtime; 457 458 u64 nr_migrations; 459 460 struct sched_statistics statistics; 461 462 #ifdef CONFIG_FAIR_GROUP_SCHED 463 int depth; 464 struct sched_entity *parent; 465 /* rq on which this entity is (to be) queued: */ 466 struct cfs_rq *cfs_rq; 467 /* rq "owned" by this entity/group: */ 468 struct cfs_rq *my_q; 469 #endif 470 471 #ifdef CONFIG_SMP 472 /* 473 * Per entity load average tracking. 474 * 475 * Put into separate cache line so it does not 476 * collide with read-mostly values above. 477 */ 478 struct sched_avg avg; 479 #endif 480 }; 481 482 struct sched_rt_entity { 483 struct list_head run_list; 484 unsigned long timeout; 485 unsigned long watchdog_stamp; 486 unsigned int time_slice; 487 unsigned short on_rq; 488 unsigned short on_list; 489 490 struct sched_rt_entity *back; 491 #ifdef CONFIG_RT_GROUP_SCHED 492 struct sched_rt_entity *parent; 493 /* rq on which this entity is (to be) queued: */ 494 struct rt_rq *rt_rq; 495 /* rq "owned" by this entity/group: */ 496 struct rt_rq *my_q; 497 #endif 498 } __randomize_layout; 499 500 struct sched_dl_entity { 501 struct rb_node rb_node; 502 503 /* 504 * Original scheduling parameters. Copied here from sched_attr 505 * during sched_setattr(), they will remain the same until 506 * the next sched_setattr(). 507 */ 508 u64 dl_runtime; /* Maximum runtime for each instance */ 509 u64 dl_deadline; /* Relative deadline of each instance */ 510 u64 dl_period; /* Separation of two instances (period) */ 511 u64 dl_bw; /* dl_runtime / dl_period */ 512 u64 dl_density; /* dl_runtime / dl_deadline */ 513 514 /* 515 * Actual scheduling parameters. Initialized with the values above, 516 * they are continously updated during task execution. Note that 517 * the remaining runtime could be < 0 in case we are in overrun. 518 */ 519 s64 runtime; /* Remaining runtime for this instance */ 520 u64 deadline; /* Absolute deadline for this instance */ 521 unsigned int flags; /* Specifying the scheduler behaviour */ 522 523 /* 524 * Some bool flags: 525 * 526 * @dl_throttled tells if we exhausted the runtime. If so, the 527 * task has to wait for a replenishment to be performed at the 528 * next firing of dl_timer. 529 * 530 * @dl_boosted tells if we are boosted due to DI. If so we are 531 * outside bandwidth enforcement mechanism (but only until we 532 * exit the critical section); 533 * 534 * @dl_yielded tells if task gave up the CPU before consuming 535 * all its available runtime during the last job. 536 * 537 * @dl_non_contending tells if the task is inactive while still 538 * contributing to the active utilization. In other words, it 539 * indicates if the inactive timer has been armed and its handler 540 * has not been executed yet. This flag is useful to avoid race 541 * conditions between the inactive timer handler and the wakeup 542 * code. 543 * 544 * @dl_overrun tells if the task asked to be informed about runtime 545 * overruns. 546 */ 547 unsigned int dl_throttled : 1; 548 unsigned int dl_boosted : 1; 549 unsigned int dl_yielded : 1; 550 unsigned int dl_non_contending : 1; 551 unsigned int dl_overrun : 1; 552 553 /* 554 * Bandwidth enforcement timer. Each -deadline task has its 555 * own bandwidth to be enforced, thus we need one timer per task. 556 */ 557 struct hrtimer dl_timer; 558 559 /* 560 * Inactive timer, responsible for decreasing the active utilization 561 * at the "0-lag time". When a -deadline task blocks, it contributes 562 * to GRUB's active utilization until the "0-lag time", hence a 563 * timer is needed to decrease the active utilization at the correct 564 * time. 565 */ 566 struct hrtimer inactive_timer; 567 }; 568 569 union rcu_special { 570 struct { 571 u8 blocked; 572 u8 need_qs; 573 u8 exp_need_qs; 574 575 /* Otherwise the compiler can store garbage here: */ 576 u8 pad; 577 } b; /* Bits. */ 578 u32 s; /* Set of bits. */ 579 }; 580 581 enum perf_event_task_context { 582 perf_invalid_context = -1, 583 perf_hw_context = 0, 584 perf_sw_context, 585 perf_nr_task_contexts, 586 }; 587 588 struct wake_q_node { 589 struct wake_q_node *next; 590 }; 591 592 struct task_struct { 593 #ifdef CONFIG_THREAD_INFO_IN_TASK 594 /* 595 * For reasons of header soup (see current_thread_info()), this 596 * must be the first element of task_struct. 597 */ 598 struct thread_info thread_info; 599 #endif 600 /* -1 unrunnable, 0 runnable, >0 stopped: */ 601 volatile long state; 602 603 /* 604 * This begins the randomizable portion of task_struct. Only 605 * scheduling-critical items should be added above here. 606 */ 607 randomized_struct_fields_start 608 609 void *stack; 610 atomic_t usage; 611 /* Per task flags (PF_*), defined further below: */ 612 unsigned int flags; 613 unsigned int ptrace; 614 615 #ifdef CONFIG_SMP 616 struct llist_node wake_entry; 617 int on_cpu; 618 #ifdef CONFIG_THREAD_INFO_IN_TASK 619 /* Current CPU: */ 620 unsigned int cpu; 621 #endif 622 unsigned int wakee_flips; 623 unsigned long wakee_flip_decay_ts; 624 struct task_struct *last_wakee; 625 626 /* 627 * recent_used_cpu is initially set as the last CPU used by a task 628 * that wakes affine another task. Waker/wakee relationships can 629 * push tasks around a CPU where each wakeup moves to the next one. 630 * Tracking a recently used CPU allows a quick search for a recently 631 * used CPU that may be idle. 632 */ 633 int recent_used_cpu; 634 int wake_cpu; 635 #endif 636 int on_rq; 637 638 int prio; 639 int static_prio; 640 int normal_prio; 641 unsigned int rt_priority; 642 643 const struct sched_class *sched_class; 644 struct sched_entity se; 645 struct sched_rt_entity rt; 646 #ifdef CONFIG_CGROUP_SCHED 647 struct task_group *sched_task_group; 648 #endif 649 struct sched_dl_entity dl; 650 651 #ifdef CONFIG_PREEMPT_NOTIFIERS 652 /* List of struct preempt_notifier: */ 653 struct hlist_head preempt_notifiers; 654 #endif 655 656 #ifdef CONFIG_BLK_DEV_IO_TRACE 657 unsigned int btrace_seq; 658 #endif 659 660 unsigned int policy; 661 int nr_cpus_allowed; 662 cpumask_t cpus_allowed; 663 664 #ifdef CONFIG_PREEMPT_RCU 665 int rcu_read_lock_nesting; 666 union rcu_special rcu_read_unlock_special; 667 struct list_head rcu_node_entry; 668 struct rcu_node *rcu_blocked_node; 669 #endif /* #ifdef CONFIG_PREEMPT_RCU */ 670 671 #ifdef CONFIG_TASKS_RCU 672 unsigned long rcu_tasks_nvcsw; 673 u8 rcu_tasks_holdout; 674 u8 rcu_tasks_idx; 675 int rcu_tasks_idle_cpu; 676 struct list_head rcu_tasks_holdout_list; 677 #endif /* #ifdef CONFIG_TASKS_RCU */ 678 679 struct sched_info sched_info; 680 681 struct list_head tasks; 682 #ifdef CONFIG_SMP 683 struct plist_node pushable_tasks; 684 struct rb_node pushable_dl_tasks; 685 #endif 686 687 struct mm_struct *mm; 688 struct mm_struct *active_mm; 689 690 /* Per-thread vma caching: */ 691 struct vmacache vmacache; 692 693 #ifdef SPLIT_RSS_COUNTING 694 struct task_rss_stat rss_stat; 695 #endif 696 int exit_state; 697 int exit_code; 698 int exit_signal; 699 /* The signal sent when the parent dies: */ 700 int pdeath_signal; 701 /* JOBCTL_*, siglock protected: */ 702 unsigned long jobctl; 703 704 /* Used for emulating ABI behavior of previous Linux versions: */ 705 unsigned int personality; 706 707 /* Scheduler bits, serialized by scheduler locks: */ 708 unsigned sched_reset_on_fork:1; 709 unsigned sched_contributes_to_load:1; 710 unsigned sched_migrated:1; 711 unsigned sched_remote_wakeup:1; 712 /* Force alignment to the next boundary: */ 713 unsigned :0; 714 715 /* Unserialized, strictly 'current' */ 716 717 /* Bit to tell LSMs we're in execve(): */ 718 unsigned in_execve:1; 719 unsigned in_iowait:1; 720 #ifndef TIF_RESTORE_SIGMASK 721 unsigned restore_sigmask:1; 722 #endif 723 #ifdef CONFIG_MEMCG 724 unsigned memcg_may_oom:1; 725 #ifndef CONFIG_SLOB 726 unsigned memcg_kmem_skip_account:1; 727 #endif 728 #endif 729 #ifdef CONFIG_COMPAT_BRK 730 unsigned brk_randomized:1; 731 #endif 732 #ifdef CONFIG_CGROUPS 733 /* disallow userland-initiated cgroup migration */ 734 unsigned no_cgroup_migration:1; 735 #endif 736 737 unsigned long atomic_flags; /* Flags requiring atomic access. */ 738 739 struct restart_block restart_block; 740 741 pid_t pid; 742 pid_t tgid; 743 744 #ifdef CONFIG_CC_STACKPROTECTOR 745 /* Canary value for the -fstack-protector GCC feature: */ 746 unsigned long stack_canary; 747 #endif 748 /* 749 * Pointers to the (original) parent process, youngest child, younger sibling, 750 * older sibling, respectively. (p->father can be replaced with 751 * p->real_parent->pid) 752 */ 753 754 /* Real parent process: */ 755 struct task_struct __rcu *real_parent; 756 757 /* Recipient of SIGCHLD, wait4() reports: */ 758 struct task_struct __rcu *parent; 759 760 /* 761 * Children/sibling form the list of natural children: 762 */ 763 struct list_head children; 764 struct list_head sibling; 765 struct task_struct *group_leader; 766 767 /* 768 * 'ptraced' is the list of tasks this task is using ptrace() on. 769 * 770 * This includes both natural children and PTRACE_ATTACH targets. 771 * 'ptrace_entry' is this task's link on the p->parent->ptraced list. 772 */ 773 struct list_head ptraced; 774 struct list_head ptrace_entry; 775 776 /* PID/PID hash table linkage. */ 777 struct pid_link pids[PIDTYPE_MAX]; 778 struct list_head thread_group; 779 struct list_head thread_node; 780 781 struct completion *vfork_done; 782 783 /* CLONE_CHILD_SETTID: */ 784 int __user *set_child_tid; 785 786 /* CLONE_CHILD_CLEARTID: */ 787 int __user *clear_child_tid; 788 789 u64 utime; 790 u64 stime; 791 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME 792 u64 utimescaled; 793 u64 stimescaled; 794 #endif 795 u64 gtime; 796 struct prev_cputime prev_cputime; 797 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN 798 struct vtime vtime; 799 #endif 800 801 #ifdef CONFIG_NO_HZ_FULL 802 atomic_t tick_dep_mask; 803 #endif 804 /* Context switch counts: */ 805 unsigned long nvcsw; 806 unsigned long nivcsw; 807 808 /* Monotonic time in nsecs: */ 809 u64 start_time; 810 811 /* Boot based time in nsecs: */ 812 u64 real_start_time; 813 814 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */ 815 unsigned long min_flt; 816 unsigned long maj_flt; 817 818 #ifdef CONFIG_POSIX_TIMERS 819 struct task_cputime cputime_expires; 820 struct list_head cpu_timers[3]; 821 #endif 822 823 /* Process credentials: */ 824 825 /* Tracer's credentials at attach: */ 826 const struct cred __rcu *ptracer_cred; 827 828 /* Objective and real subjective task credentials (COW): */ 829 const struct cred __rcu *real_cred; 830 831 /* Effective (overridable) subjective task credentials (COW): */ 832 const struct cred __rcu *cred; 833 834 /* 835 * executable name, excluding path. 836 * 837 * - normally initialized setup_new_exec() 838 * - access it with [gs]et_task_comm() 839 * - lock it with task_lock() 840 */ 841 char comm[TASK_COMM_LEN]; 842 843 struct nameidata *nameidata; 844 845 #ifdef CONFIG_SYSVIPC 846 struct sysv_sem sysvsem; 847 struct sysv_shm sysvshm; 848 #endif 849 #ifdef CONFIG_DETECT_HUNG_TASK 850 unsigned long last_switch_count; 851 #endif 852 /* Filesystem information: */ 853 struct fs_struct *fs; 854 855 /* Open file information: */ 856 struct files_struct *files; 857 858 /* Namespaces: */ 859 struct nsproxy *nsproxy; 860 861 /* Signal handlers: */ 862 struct signal_struct *signal; 863 struct sighand_struct *sighand; 864 sigset_t blocked; 865 sigset_t real_blocked; 866 /* Restored if set_restore_sigmask() was used: */ 867 sigset_t saved_sigmask; 868 struct sigpending pending; 869 unsigned long sas_ss_sp; 870 size_t sas_ss_size; 871 unsigned int sas_ss_flags; 872 873 struct callback_head *task_works; 874 875 struct audit_context *audit_context; 876 #ifdef CONFIG_AUDITSYSCALL 877 kuid_t loginuid; 878 unsigned int sessionid; 879 #endif 880 struct seccomp seccomp; 881 882 /* Thread group tracking: */ 883 u32 parent_exec_id; 884 u32 self_exec_id; 885 886 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */ 887 spinlock_t alloc_lock; 888 889 /* Protection of the PI data structures: */ 890 raw_spinlock_t pi_lock; 891 892 struct wake_q_node wake_q; 893 894 #ifdef CONFIG_RT_MUTEXES 895 /* PI waiters blocked on a rt_mutex held by this task: */ 896 struct rb_root_cached pi_waiters; 897 /* Updated under owner's pi_lock and rq lock */ 898 struct task_struct *pi_top_task; 899 /* Deadlock detection and priority inheritance handling: */ 900 struct rt_mutex_waiter *pi_blocked_on; 901 #endif 902 903 #ifdef CONFIG_DEBUG_MUTEXES 904 /* Mutex deadlock detection: */ 905 struct mutex_waiter *blocked_on; 906 #endif 907 908 #ifdef CONFIG_TRACE_IRQFLAGS 909 unsigned int irq_events; 910 unsigned long hardirq_enable_ip; 911 unsigned long hardirq_disable_ip; 912 unsigned int hardirq_enable_event; 913 unsigned int hardirq_disable_event; 914 int hardirqs_enabled; 915 int hardirq_context; 916 unsigned long softirq_disable_ip; 917 unsigned long softirq_enable_ip; 918 unsigned int softirq_disable_event; 919 unsigned int softirq_enable_event; 920 int softirqs_enabled; 921 int softirq_context; 922 #endif 923 924 #ifdef CONFIG_LOCKDEP 925 # define MAX_LOCK_DEPTH 48UL 926 u64 curr_chain_key; 927 int lockdep_depth; 928 unsigned int lockdep_recursion; 929 struct held_lock held_locks[MAX_LOCK_DEPTH]; 930 #endif 931 932 #ifdef CONFIG_UBSAN 933 unsigned int in_ubsan; 934 #endif 935 936 /* Journalling filesystem info: */ 937 void *journal_info; 938 939 /* Stacked block device info: */ 940 struct bio_list *bio_list; 941 942 #ifdef CONFIG_BLOCK 943 /* Stack plugging: */ 944 struct blk_plug *plug; 945 #endif 946 947 /* VM state: */ 948 struct reclaim_state *reclaim_state; 949 950 struct backing_dev_info *backing_dev_info; 951 952 struct io_context *io_context; 953 954 /* Ptrace state: */ 955 unsigned long ptrace_message; 956 siginfo_t *last_siginfo; 957 958 struct task_io_accounting ioac; 959 #ifdef CONFIG_TASK_XACCT 960 /* Accumulated RSS usage: */ 961 u64 acct_rss_mem1; 962 /* Accumulated virtual memory usage: */ 963 u64 acct_vm_mem1; 964 /* stime + utime since last update: */ 965 u64 acct_timexpd; 966 #endif 967 #ifdef CONFIG_CPUSETS 968 /* Protected by ->alloc_lock: */ 969 nodemask_t mems_allowed; 970 /* Seqence number to catch updates: */ 971 seqcount_t mems_allowed_seq; 972 int cpuset_mem_spread_rotor; 973 int cpuset_slab_spread_rotor; 974 #endif 975 #ifdef CONFIG_CGROUPS 976 /* Control Group info protected by css_set_lock: */ 977 struct css_set __rcu *cgroups; 978 /* cg_list protected by css_set_lock and tsk->alloc_lock: */ 979 struct list_head cg_list; 980 #endif 981 #ifdef CONFIG_INTEL_RDT 982 u32 closid; 983 u32 rmid; 984 #endif 985 #ifdef CONFIG_FUTEX 986 struct robust_list_head __user *robust_list; 987 #ifdef CONFIG_COMPAT 988 struct compat_robust_list_head __user *compat_robust_list; 989 #endif 990 struct list_head pi_state_list; 991 struct futex_pi_state *pi_state_cache; 992 #endif 993 #ifdef CONFIG_PERF_EVENTS 994 struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts]; 995 struct mutex perf_event_mutex; 996 struct list_head perf_event_list; 997 #endif 998 #ifdef CONFIG_DEBUG_PREEMPT 999 unsigned long preempt_disable_ip; 1000 #endif 1001 #ifdef CONFIG_NUMA 1002 /* Protected by alloc_lock: */ 1003 struct mempolicy *mempolicy; 1004 short il_prev; 1005 short pref_node_fork; 1006 #endif 1007 #ifdef CONFIG_NUMA_BALANCING 1008 int numa_scan_seq; 1009 unsigned int numa_scan_period; 1010 unsigned int numa_scan_period_max; 1011 int numa_preferred_nid; 1012 unsigned long numa_migrate_retry; 1013 /* Migration stamp: */ 1014 u64 node_stamp; 1015 u64 last_task_numa_placement; 1016 u64 last_sum_exec_runtime; 1017 struct callback_head numa_work; 1018 1019 struct list_head numa_entry; 1020 struct numa_group *numa_group; 1021 1022 /* 1023 * numa_faults is an array split into four regions: 1024 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer 1025 * in this precise order. 1026 * 1027 * faults_memory: Exponential decaying average of faults on a per-node 1028 * basis. Scheduling placement decisions are made based on these 1029 * counts. The values remain static for the duration of a PTE scan. 1030 * faults_cpu: Track the nodes the process was running on when a NUMA 1031 * hinting fault was incurred. 1032 * faults_memory_buffer and faults_cpu_buffer: Record faults per node 1033 * during the current scan window. When the scan completes, the counts 1034 * in faults_memory and faults_cpu decay and these values are copied. 1035 */ 1036 unsigned long *numa_faults; 1037 unsigned long total_numa_faults; 1038 1039 /* 1040 * numa_faults_locality tracks if faults recorded during the last 1041 * scan window were remote/local or failed to migrate. The task scan 1042 * period is adapted based on the locality of the faults with different 1043 * weights depending on whether they were shared or private faults 1044 */ 1045 unsigned long numa_faults_locality[3]; 1046 1047 unsigned long numa_pages_migrated; 1048 #endif /* CONFIG_NUMA_BALANCING */ 1049 1050 struct tlbflush_unmap_batch tlb_ubc; 1051 1052 struct rcu_head rcu; 1053 1054 /* Cache last used pipe for splice(): */ 1055 struct pipe_inode_info *splice_pipe; 1056 1057 struct page_frag task_frag; 1058 1059 #ifdef CONFIG_TASK_DELAY_ACCT 1060 struct task_delay_info *delays; 1061 #endif 1062 1063 #ifdef CONFIG_FAULT_INJECTION 1064 int make_it_fail; 1065 unsigned int fail_nth; 1066 #endif 1067 /* 1068 * When (nr_dirtied >= nr_dirtied_pause), it's time to call 1069 * balance_dirty_pages() for a dirty throttling pause: 1070 */ 1071 int nr_dirtied; 1072 int nr_dirtied_pause; 1073 /* Start of a write-and-pause period: */ 1074 unsigned long dirty_paused_when; 1075 1076 #ifdef CONFIG_LATENCYTOP 1077 int latency_record_count; 1078 struct latency_record latency_record[LT_SAVECOUNT]; 1079 #endif 1080 /* 1081 * Time slack values; these are used to round up poll() and 1082 * select() etc timeout values. These are in nanoseconds. 1083 */ 1084 u64 timer_slack_ns; 1085 u64 default_timer_slack_ns; 1086 1087 #ifdef CONFIG_KASAN 1088 unsigned int kasan_depth; 1089 #endif 1090 1091 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 1092 /* Index of current stored address in ret_stack: */ 1093 int curr_ret_stack; 1094 1095 /* Stack of return addresses for return function tracing: */ 1096 struct ftrace_ret_stack *ret_stack; 1097 1098 /* Timestamp for last schedule: */ 1099 unsigned long long ftrace_timestamp; 1100 1101 /* 1102 * Number of functions that haven't been traced 1103 * because of depth overrun: 1104 */ 1105 atomic_t trace_overrun; 1106 1107 /* Pause tracing: */ 1108 atomic_t tracing_graph_pause; 1109 #endif 1110 1111 #ifdef CONFIG_TRACING 1112 /* State flags for use by tracers: */ 1113 unsigned long trace; 1114 1115 /* Bitmask and counter of trace recursion: */ 1116 unsigned long trace_recursion; 1117 #endif /* CONFIG_TRACING */ 1118 1119 #ifdef CONFIG_KCOV 1120 /* Coverage collection mode enabled for this task (0 if disabled): */ 1121 enum kcov_mode kcov_mode; 1122 1123 /* Size of the kcov_area: */ 1124 unsigned int kcov_size; 1125 1126 /* Buffer for coverage collection: */ 1127 void *kcov_area; 1128 1129 /* KCOV descriptor wired with this task or NULL: */ 1130 struct kcov *kcov; 1131 #endif 1132 1133 #ifdef CONFIG_MEMCG 1134 struct mem_cgroup *memcg_in_oom; 1135 gfp_t memcg_oom_gfp_mask; 1136 int memcg_oom_order; 1137 1138 /* Number of pages to reclaim on returning to userland: */ 1139 unsigned int memcg_nr_pages_over_high; 1140 #endif 1141 1142 #ifdef CONFIG_UPROBES 1143 struct uprobe_task *utask; 1144 #endif 1145 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE) 1146 unsigned int sequential_io; 1147 unsigned int sequential_io_avg; 1148 #endif 1149 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 1150 unsigned long task_state_change; 1151 #endif 1152 int pagefault_disabled; 1153 #ifdef CONFIG_MMU 1154 struct task_struct *oom_reaper_list; 1155 #endif 1156 #ifdef CONFIG_VMAP_STACK 1157 struct vm_struct *stack_vm_area; 1158 #endif 1159 #ifdef CONFIG_THREAD_INFO_IN_TASK 1160 /* A live task holds one reference: */ 1161 atomic_t stack_refcount; 1162 #endif 1163 #ifdef CONFIG_LIVEPATCH 1164 int patch_state; 1165 #endif 1166 #ifdef CONFIG_SECURITY 1167 /* Used by LSM modules for access restriction: */ 1168 void *security; 1169 #endif 1170 1171 /* 1172 * New fields for task_struct should be added above here, so that 1173 * they are included in the randomized portion of task_struct. 1174 */ 1175 randomized_struct_fields_end 1176 1177 /* CPU-specific state of this task: */ 1178 struct thread_struct thread; 1179 1180 /* 1181 * WARNING: on x86, 'thread_struct' contains a variable-sized 1182 * structure. It *MUST* be at the end of 'task_struct'. 1183 * 1184 * Do not put anything below here! 1185 */ 1186 }; 1187 1188 static inline struct pid *task_pid(struct task_struct *task) 1189 { 1190 return task->pids[PIDTYPE_PID].pid; 1191 } 1192 1193 static inline struct pid *task_tgid(struct task_struct *task) 1194 { 1195 return task->group_leader->pids[PIDTYPE_PID].pid; 1196 } 1197 1198 /* 1199 * Without tasklist or RCU lock it is not safe to dereference 1200 * the result of task_pgrp/task_session even if task == current, 1201 * we can race with another thread doing sys_setsid/sys_setpgid. 1202 */ 1203 static inline struct pid *task_pgrp(struct task_struct *task) 1204 { 1205 return task->group_leader->pids[PIDTYPE_PGID].pid; 1206 } 1207 1208 static inline struct pid *task_session(struct task_struct *task) 1209 { 1210 return task->group_leader->pids[PIDTYPE_SID].pid; 1211 } 1212 1213 /* 1214 * the helpers to get the task's different pids as they are seen 1215 * from various namespaces 1216 * 1217 * task_xid_nr() : global id, i.e. the id seen from the init namespace; 1218 * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of 1219 * current. 1220 * task_xid_nr_ns() : id seen from the ns specified; 1221 * 1222 * see also pid_nr() etc in include/linux/pid.h 1223 */ 1224 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns); 1225 1226 static inline pid_t task_pid_nr(struct task_struct *tsk) 1227 { 1228 return tsk->pid; 1229 } 1230 1231 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1232 { 1233 return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns); 1234 } 1235 1236 static inline pid_t task_pid_vnr(struct task_struct *tsk) 1237 { 1238 return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL); 1239 } 1240 1241 1242 static inline pid_t task_tgid_nr(struct task_struct *tsk) 1243 { 1244 return tsk->tgid; 1245 } 1246 1247 /** 1248 * pid_alive - check that a task structure is not stale 1249 * @p: Task structure to be checked. 1250 * 1251 * Test if a process is not yet dead (at most zombie state) 1252 * If pid_alive fails, then pointers within the task structure 1253 * can be stale and must not be dereferenced. 1254 * 1255 * Return: 1 if the process is alive. 0 otherwise. 1256 */ 1257 static inline int pid_alive(const struct task_struct *p) 1258 { 1259 return p->pids[PIDTYPE_PID].pid != NULL; 1260 } 1261 1262 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1263 { 1264 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns); 1265 } 1266 1267 static inline pid_t task_pgrp_vnr(struct task_struct *tsk) 1268 { 1269 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL); 1270 } 1271 1272 1273 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1274 { 1275 return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns); 1276 } 1277 1278 static inline pid_t task_session_vnr(struct task_struct *tsk) 1279 { 1280 return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL); 1281 } 1282 1283 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) 1284 { 1285 return __task_pid_nr_ns(tsk, __PIDTYPE_TGID, ns); 1286 } 1287 1288 static inline pid_t task_tgid_vnr(struct task_struct *tsk) 1289 { 1290 return __task_pid_nr_ns(tsk, __PIDTYPE_TGID, NULL); 1291 } 1292 1293 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns) 1294 { 1295 pid_t pid = 0; 1296 1297 rcu_read_lock(); 1298 if (pid_alive(tsk)) 1299 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns); 1300 rcu_read_unlock(); 1301 1302 return pid; 1303 } 1304 1305 static inline pid_t task_ppid_nr(const struct task_struct *tsk) 1306 { 1307 return task_ppid_nr_ns(tsk, &init_pid_ns); 1308 } 1309 1310 /* Obsolete, do not use: */ 1311 static inline pid_t task_pgrp_nr(struct task_struct *tsk) 1312 { 1313 return task_pgrp_nr_ns(tsk, &init_pid_ns); 1314 } 1315 1316 #define TASK_REPORT_IDLE (TASK_REPORT + 1) 1317 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1) 1318 1319 static inline unsigned int task_state_index(struct task_struct *tsk) 1320 { 1321 unsigned int tsk_state = READ_ONCE(tsk->state); 1322 unsigned int state = (tsk_state | tsk->exit_state) & TASK_REPORT; 1323 1324 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX); 1325 1326 if (tsk_state == TASK_IDLE) 1327 state = TASK_REPORT_IDLE; 1328 1329 return fls(state); 1330 } 1331 1332 static inline char task_index_to_char(unsigned int state) 1333 { 1334 static const char state_char[] = "RSDTtXZPI"; 1335 1336 BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1); 1337 1338 return state_char[state]; 1339 } 1340 1341 static inline char task_state_to_char(struct task_struct *tsk) 1342 { 1343 return task_index_to_char(task_state_index(tsk)); 1344 } 1345 1346 /** 1347 * is_global_init - check if a task structure is init. Since init 1348 * is free to have sub-threads we need to check tgid. 1349 * @tsk: Task structure to be checked. 1350 * 1351 * Check if a task structure is the first user space task the kernel created. 1352 * 1353 * Return: 1 if the task structure is init. 0 otherwise. 1354 */ 1355 static inline int is_global_init(struct task_struct *tsk) 1356 { 1357 return task_tgid_nr(tsk) == 1; 1358 } 1359 1360 extern struct pid *cad_pid; 1361 1362 /* 1363 * Per process flags 1364 */ 1365 #define PF_IDLE 0x00000002 /* I am an IDLE thread */ 1366 #define PF_EXITING 0x00000004 /* Getting shut down */ 1367 #define PF_EXITPIDONE 0x00000008 /* PI exit done on shut down */ 1368 #define PF_VCPU 0x00000010 /* I'm a virtual CPU */ 1369 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */ 1370 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */ 1371 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */ 1372 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */ 1373 #define PF_DUMPCORE 0x00000200 /* Dumped core */ 1374 #define PF_SIGNALED 0x00000400 /* Killed by a signal */ 1375 #define PF_MEMALLOC 0x00000800 /* Allocating memory */ 1376 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */ 1377 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */ 1378 #define PF_USED_ASYNC 0x00004000 /* Used async_schedule*(), used by module init */ 1379 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */ 1380 #define PF_FROZEN 0x00010000 /* Frozen for system suspend */ 1381 #define PF_KSWAPD 0x00020000 /* I am kswapd */ 1382 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocation requests will inherit GFP_NOFS */ 1383 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocation requests will inherit GFP_NOIO */ 1384 #define PF_LESS_THROTTLE 0x00100000 /* Throttle me less: I clean memory */ 1385 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */ 1386 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */ 1387 #define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */ 1388 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_allowed */ 1389 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */ 1390 #define PF_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */ 1391 #define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezable */ 1392 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */ 1393 1394 /* 1395 * Only the _current_ task can read/write to tsk->flags, but other 1396 * tasks can access tsk->flags in readonly mode for example 1397 * with tsk_used_math (like during threaded core dumping). 1398 * There is however an exception to this rule during ptrace 1399 * or during fork: the ptracer task is allowed to write to the 1400 * child->flags of its traced child (same goes for fork, the parent 1401 * can write to the child->flags), because we're guaranteed the 1402 * child is not running and in turn not changing child->flags 1403 * at the same time the parent does it. 1404 */ 1405 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0) 1406 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0) 1407 #define clear_used_math() clear_stopped_child_used_math(current) 1408 #define set_used_math() set_stopped_child_used_math(current) 1409 1410 #define conditional_stopped_child_used_math(condition, child) \ 1411 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0) 1412 1413 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current) 1414 1415 #define copy_to_stopped_child_used_math(child) \ 1416 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0) 1417 1418 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */ 1419 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH) 1420 #define used_math() tsk_used_math(current) 1421 1422 static inline bool is_percpu_thread(void) 1423 { 1424 #ifdef CONFIG_SMP 1425 return (current->flags & PF_NO_SETAFFINITY) && 1426 (current->nr_cpus_allowed == 1); 1427 #else 1428 return true; 1429 #endif 1430 } 1431 1432 /* Per-process atomic flags. */ 1433 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */ 1434 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */ 1435 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */ 1436 #define PFA_SPEC_SSB_DISABLE 3 /* Speculative Store Bypass disabled */ 1437 #define PFA_SPEC_SSB_FORCE_DISABLE 4 /* Speculative Store Bypass force disabled*/ 1438 1439 #define TASK_PFA_TEST(name, func) \ 1440 static inline bool task_##func(struct task_struct *p) \ 1441 { return test_bit(PFA_##name, &p->atomic_flags); } 1442 1443 #define TASK_PFA_SET(name, func) \ 1444 static inline void task_set_##func(struct task_struct *p) \ 1445 { set_bit(PFA_##name, &p->atomic_flags); } 1446 1447 #define TASK_PFA_CLEAR(name, func) \ 1448 static inline void task_clear_##func(struct task_struct *p) \ 1449 { clear_bit(PFA_##name, &p->atomic_flags); } 1450 1451 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs) 1452 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs) 1453 1454 TASK_PFA_TEST(SPREAD_PAGE, spread_page) 1455 TASK_PFA_SET(SPREAD_PAGE, spread_page) 1456 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page) 1457 1458 TASK_PFA_TEST(SPREAD_SLAB, spread_slab) 1459 TASK_PFA_SET(SPREAD_SLAB, spread_slab) 1460 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab) 1461 1462 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable) 1463 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable) 1464 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable) 1465 1466 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1467 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable) 1468 1469 static inline void 1470 current_restore_flags(unsigned long orig_flags, unsigned long flags) 1471 { 1472 current->flags &= ~flags; 1473 current->flags |= orig_flags & flags; 1474 } 1475 1476 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial); 1477 extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed); 1478 #ifdef CONFIG_SMP 1479 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask); 1480 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask); 1481 #else 1482 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) 1483 { 1484 } 1485 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) 1486 { 1487 if (!cpumask_test_cpu(0, new_mask)) 1488 return -EINVAL; 1489 return 0; 1490 } 1491 #endif 1492 1493 #ifndef cpu_relax_yield 1494 #define cpu_relax_yield() cpu_relax() 1495 #endif 1496 1497 extern int yield_to(struct task_struct *p, bool preempt); 1498 extern void set_user_nice(struct task_struct *p, long nice); 1499 extern int task_prio(const struct task_struct *p); 1500 1501 /** 1502 * task_nice - return the nice value of a given task. 1503 * @p: the task in question. 1504 * 1505 * Return: The nice value [ -20 ... 0 ... 19 ]. 1506 */ 1507 static inline int task_nice(const struct task_struct *p) 1508 { 1509 return PRIO_TO_NICE((p)->static_prio); 1510 } 1511 1512 extern int can_nice(const struct task_struct *p, const int nice); 1513 extern int task_curr(const struct task_struct *p); 1514 extern int idle_cpu(int cpu); 1515 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *); 1516 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *); 1517 extern int sched_setattr(struct task_struct *, const struct sched_attr *); 1518 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *); 1519 extern struct task_struct *idle_task(int cpu); 1520 1521 /** 1522 * is_idle_task - is the specified task an idle task? 1523 * @p: the task in question. 1524 * 1525 * Return: 1 if @p is an idle task. 0 otherwise. 1526 */ 1527 static inline bool is_idle_task(const struct task_struct *p) 1528 { 1529 return !!(p->flags & PF_IDLE); 1530 } 1531 1532 extern struct task_struct *curr_task(int cpu); 1533 extern void ia64_set_curr_task(int cpu, struct task_struct *p); 1534 1535 void yield(void); 1536 1537 union thread_union { 1538 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK 1539 struct task_struct task; 1540 #endif 1541 #ifndef CONFIG_THREAD_INFO_IN_TASK 1542 struct thread_info thread_info; 1543 #endif 1544 unsigned long stack[THREAD_SIZE/sizeof(long)]; 1545 }; 1546 1547 #ifndef CONFIG_THREAD_INFO_IN_TASK 1548 extern struct thread_info init_thread_info; 1549 #endif 1550 1551 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)]; 1552 1553 #ifdef CONFIG_THREAD_INFO_IN_TASK 1554 static inline struct thread_info *task_thread_info(struct task_struct *task) 1555 { 1556 return &task->thread_info; 1557 } 1558 #elif !defined(__HAVE_THREAD_FUNCTIONS) 1559 # define task_thread_info(task) ((struct thread_info *)(task)->stack) 1560 #endif 1561 1562 /* 1563 * find a task by one of its numerical ids 1564 * 1565 * find_task_by_pid_ns(): 1566 * finds a task by its pid in the specified namespace 1567 * find_task_by_vpid(): 1568 * finds a task by its virtual pid 1569 * 1570 * see also find_vpid() etc in include/linux/pid.h 1571 */ 1572 1573 extern struct task_struct *find_task_by_vpid(pid_t nr); 1574 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns); 1575 1576 /* 1577 * find a task by its virtual pid and get the task struct 1578 */ 1579 extern struct task_struct *find_get_task_by_vpid(pid_t nr); 1580 1581 extern int wake_up_state(struct task_struct *tsk, unsigned int state); 1582 extern int wake_up_process(struct task_struct *tsk); 1583 extern void wake_up_new_task(struct task_struct *tsk); 1584 1585 #ifdef CONFIG_SMP 1586 extern void kick_process(struct task_struct *tsk); 1587 #else 1588 static inline void kick_process(struct task_struct *tsk) { } 1589 #endif 1590 1591 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec); 1592 1593 static inline void set_task_comm(struct task_struct *tsk, const char *from) 1594 { 1595 __set_task_comm(tsk, from, false); 1596 } 1597 1598 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk); 1599 #define get_task_comm(buf, tsk) ({ \ 1600 BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN); \ 1601 __get_task_comm(buf, sizeof(buf), tsk); \ 1602 }) 1603 1604 #ifdef CONFIG_SMP 1605 void scheduler_ipi(void); 1606 extern unsigned long wait_task_inactive(struct task_struct *, long match_state); 1607 #else 1608 static inline void scheduler_ipi(void) { } 1609 static inline unsigned long wait_task_inactive(struct task_struct *p, long match_state) 1610 { 1611 return 1; 1612 } 1613 #endif 1614 1615 /* 1616 * Set thread flags in other task's structures. 1617 * See asm/thread_info.h for TIF_xxxx flags available: 1618 */ 1619 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag) 1620 { 1621 set_ti_thread_flag(task_thread_info(tsk), flag); 1622 } 1623 1624 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag) 1625 { 1626 clear_ti_thread_flag(task_thread_info(tsk), flag); 1627 } 1628 1629 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag) 1630 { 1631 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag); 1632 } 1633 1634 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag) 1635 { 1636 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag); 1637 } 1638 1639 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag) 1640 { 1641 return test_ti_thread_flag(task_thread_info(tsk), flag); 1642 } 1643 1644 static inline void set_tsk_need_resched(struct task_struct *tsk) 1645 { 1646 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 1647 } 1648 1649 static inline void clear_tsk_need_resched(struct task_struct *tsk) 1650 { 1651 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED); 1652 } 1653 1654 static inline int test_tsk_need_resched(struct task_struct *tsk) 1655 { 1656 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED)); 1657 } 1658 1659 /* 1660 * cond_resched() and cond_resched_lock(): latency reduction via 1661 * explicit rescheduling in places that are safe. The return 1662 * value indicates whether a reschedule was done in fact. 1663 * cond_resched_lock() will drop the spinlock before scheduling, 1664 * cond_resched_softirq() will enable bhs before scheduling. 1665 */ 1666 #ifndef CONFIG_PREEMPT 1667 extern int _cond_resched(void); 1668 #else 1669 static inline int _cond_resched(void) { return 0; } 1670 #endif 1671 1672 #define cond_resched() ({ \ 1673 ___might_sleep(__FILE__, __LINE__, 0); \ 1674 _cond_resched(); \ 1675 }) 1676 1677 extern int __cond_resched_lock(spinlock_t *lock); 1678 1679 #define cond_resched_lock(lock) ({ \ 1680 ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\ 1681 __cond_resched_lock(lock); \ 1682 }) 1683 1684 extern int __cond_resched_softirq(void); 1685 1686 #define cond_resched_softirq() ({ \ 1687 ___might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET); \ 1688 __cond_resched_softirq(); \ 1689 }) 1690 1691 static inline void cond_resched_rcu(void) 1692 { 1693 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU) 1694 rcu_read_unlock(); 1695 cond_resched(); 1696 rcu_read_lock(); 1697 #endif 1698 } 1699 1700 /* 1701 * Does a critical section need to be broken due to another 1702 * task waiting?: (technically does not depend on CONFIG_PREEMPT, 1703 * but a general need for low latency) 1704 */ 1705 static inline int spin_needbreak(spinlock_t *lock) 1706 { 1707 #ifdef CONFIG_PREEMPT 1708 return spin_is_contended(lock); 1709 #else 1710 return 0; 1711 #endif 1712 } 1713 1714 static __always_inline bool need_resched(void) 1715 { 1716 return unlikely(tif_need_resched()); 1717 } 1718 1719 /* 1720 * Wrappers for p->thread_info->cpu access. No-op on UP. 1721 */ 1722 #ifdef CONFIG_SMP 1723 1724 static inline unsigned int task_cpu(const struct task_struct *p) 1725 { 1726 #ifdef CONFIG_THREAD_INFO_IN_TASK 1727 return p->cpu; 1728 #else 1729 return task_thread_info(p)->cpu; 1730 #endif 1731 } 1732 1733 extern void set_task_cpu(struct task_struct *p, unsigned int cpu); 1734 1735 #else 1736 1737 static inline unsigned int task_cpu(const struct task_struct *p) 1738 { 1739 return 0; 1740 } 1741 1742 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu) 1743 { 1744 } 1745 1746 #endif /* CONFIG_SMP */ 1747 1748 /* 1749 * In order to reduce various lock holder preemption latencies provide an 1750 * interface to see if a vCPU is currently running or not. 1751 * 1752 * This allows us to terminate optimistic spin loops and block, analogous to 1753 * the native optimistic spin heuristic of testing if the lock owner task is 1754 * running or not. 1755 */ 1756 #ifndef vcpu_is_preempted 1757 # define vcpu_is_preempted(cpu) false 1758 #endif 1759 1760 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask); 1761 extern long sched_getaffinity(pid_t pid, struct cpumask *mask); 1762 1763 #ifndef TASK_SIZE_OF 1764 #define TASK_SIZE_OF(tsk) TASK_SIZE 1765 #endif 1766 1767 #endif 1768