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