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