1 /* SPDX-License-Identifier: GPL-2.0 */
6 * Define 'struct task_struct' and provide the main scheduler
7 * APIs (schedule(), wakeup variants, etc.)
10 #include <uapi/linux/sched.h>
12 #include <asm/current.h>
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 #include <linux/rseq.h>
32 /* task_struct member predeclarations (sorted alphabetically): */
34 struct backing_dev_info;
39 struct futex_pi_state;
44 struct perf_event_context;
46 struct pipe_inode_info;
49 struct robust_list_head;
53 struct sighand_struct;
55 struct task_delay_info;
59 * Task state bitmask. NOTE! These bits are also
60 * encoded in fs/proc/array.c: get_task_state().
62 * We have two separate sets of flags: task->state
63 * is about runnability, while task->exit_state are
64 * about the task exiting. Confusing, but this way
65 * modifying one set can't modify the other one by
69 /* Used in tsk->state: */
70 #define TASK_RUNNING 0x0000
71 #define TASK_INTERRUPTIBLE 0x0001
72 #define TASK_UNINTERRUPTIBLE 0x0002
73 #define __TASK_STOPPED 0x0004
74 #define __TASK_TRACED 0x0008
75 /* Used in tsk->exit_state: */
76 #define EXIT_DEAD 0x0010
77 #define EXIT_ZOMBIE 0x0020
78 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD)
79 /* Used in tsk->state again: */
80 #define TASK_PARKED 0x0040
81 #define TASK_DEAD 0x0080
82 #define TASK_WAKEKILL 0x0100
83 #define TASK_WAKING 0x0200
84 #define TASK_NOLOAD 0x0400
85 #define TASK_NEW 0x0800
86 #define TASK_STATE_MAX 0x1000
88 /* Convenience macros for the sake of set_current_state: */
89 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
90 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED)
91 #define TASK_TRACED (TASK_WAKEKILL | __TASK_TRACED)
93 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
95 /* Convenience macros for the sake of wake_up(): */
96 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
98 /* get_task_state(): */
99 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \
100 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
101 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
104 #define task_is_traced(task) ((task->state & __TASK_TRACED) != 0)
106 #define task_is_stopped(task) ((task->state & __TASK_STOPPED) != 0)
108 #define task_is_stopped_or_traced(task) ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
110 #define task_contributes_to_load(task) ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
111 (task->flags & PF_FROZEN) == 0 && \
112 (task->state & TASK_NOLOAD) == 0)
114 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
117 * Special states are those that do not use the normal wait-loop pattern. See
118 * the comment with set_special_state().
120 #define is_special_task_state(state) \
121 ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD))
123 #define __set_current_state(state_value) \
125 WARN_ON_ONCE(is_special_task_state(state_value));\
126 current->task_state_change = _THIS_IP_; \
127 current->state = (state_value); \
130 #define set_current_state(state_value) \
132 WARN_ON_ONCE(is_special_task_state(state_value));\
133 current->task_state_change = _THIS_IP_; \
134 smp_store_mb(current->state, (state_value)); \
137 #define set_special_state(state_value) \
139 unsigned long flags; /* may shadow */ \
140 WARN_ON_ONCE(!is_special_task_state(state_value)); \
141 raw_spin_lock_irqsave(¤t->pi_lock, flags); \
142 current->task_state_change = _THIS_IP_; \
143 current->state = (state_value); \
144 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \
148 * set_current_state() includes a barrier so that the write of current->state
149 * is correctly serialised wrt the caller's subsequent test of whether to
153 * set_current_state(TASK_UNINTERRUPTIBLE);
159 * __set_current_state(TASK_RUNNING);
161 * If the caller does not need such serialisation (because, for instance, the
162 * condition test and condition change and wakeup are under the same lock) then
163 * use __set_current_state().
165 * The above is typically ordered against the wakeup, which does:
167 * need_sleep = false;
168 * wake_up_state(p, TASK_UNINTERRUPTIBLE);
170 * where wake_up_state() executes a full memory barrier before accessing the
173 * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is,
174 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
175 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
177 * However, with slightly different timing the wakeup TASK_RUNNING store can
178 * also collide with the TASK_UNINTERRUPTIBLE store. Loosing that store is not
179 * a problem either because that will result in one extra go around the loop
180 * and our @cond test will save the day.
182 * Also see the comments of try_to_wake_up().
184 #define __set_current_state(state_value) \
185 current->state = (state_value)
187 #define set_current_state(state_value) \
188 smp_store_mb(current->state, (state_value))
191 * set_special_state() should be used for those states when the blocking task
192 * can not use the regular condition based wait-loop. In that case we must
193 * serialize against wakeups such that any possible in-flight TASK_RUNNING stores
194 * will not collide with our state change.
196 #define set_special_state(state_value) \
198 unsigned long flags; /* may shadow */ \
199 raw_spin_lock_irqsave(¤t->pi_lock, flags); \
200 current->state = (state_value); \
201 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \
206 /* Task command name length: */
207 #define TASK_COMM_LEN 16
209 extern void scheduler_tick(void);
211 #define MAX_SCHEDULE_TIMEOUT LONG_MAX
213 extern long schedule_timeout(long timeout);
214 extern long schedule_timeout_interruptible(long timeout);
215 extern long schedule_timeout_killable(long timeout);
216 extern long schedule_timeout_uninterruptible(long timeout);
217 extern long schedule_timeout_idle(long timeout);
218 asmlinkage void schedule(void);
219 extern void schedule_preempt_disabled(void);
221 extern int __must_check io_schedule_prepare(void);
222 extern void io_schedule_finish(int token);
223 extern long io_schedule_timeout(long timeout);
224 extern void io_schedule(void);
227 * struct prev_cputime - snapshot of system and user cputime
228 * @utime: time spent in user mode
229 * @stime: time spent in system mode
230 * @lock: protects the above two fields
232 * Stores previous user/system time values such that we can guarantee
235 struct prev_cputime {
236 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
244 * struct task_cputime - collected CPU time counts
245 * @utime: time spent in user mode, in nanoseconds
246 * @stime: time spent in kernel mode, in nanoseconds
247 * @sum_exec_runtime: total time spent on the CPU, in nanoseconds
249 * This structure groups together three kinds of CPU time that are tracked for
250 * threads and thread groups. Most things considering CPU time want to group
251 * these counts together and treat all three of them in parallel.
253 struct task_cputime {
256 unsigned long long sum_exec_runtime;
259 /* Alternate field names when used on cache expirations: */
260 #define virt_exp utime
261 #define prof_exp stime
262 #define sched_exp sum_exec_runtime
265 /* Task is sleeping or running in a CPU with VTIME inactive: */
267 /* Task runs in userspace in a CPU with VTIME active: */
269 /* Task runs in kernelspace in a CPU with VTIME active: */
275 unsigned long long starttime;
276 enum vtime_state state;
283 #ifdef CONFIG_SCHED_INFO
284 /* Cumulative counters: */
286 /* # of times we have run on this CPU: */
287 unsigned long pcount;
289 /* Time spent waiting on a runqueue: */
290 unsigned long long run_delay;
294 /* When did we last run on a CPU? */
295 unsigned long long last_arrival;
297 /* When were we last queued to run? */
298 unsigned long long last_queued;
300 #endif /* CONFIG_SCHED_INFO */
304 * Integer metrics need fixed point arithmetic, e.g., sched/fair
305 * has a few: load, load_avg, util_avg, freq, and capacity.
307 * We define a basic fixed point arithmetic range, and then formalize
308 * all these metrics based on that basic range.
310 # define SCHED_FIXEDPOINT_SHIFT 10
311 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT)
314 unsigned long weight;
319 * struct util_est - Estimation utilization of FAIR tasks
320 * @enqueued: instantaneous estimated utilization of a task/cpu
321 * @ewma: the Exponential Weighted Moving Average (EWMA)
322 * utilization of a task
324 * Support data structure to track an Exponential Weighted Moving Average
325 * (EWMA) of a FAIR task's utilization. New samples are added to the moving
326 * average each time a task completes an activation. Sample's weight is chosen
327 * so that the EWMA will be relatively insensitive to transient changes to the
330 * The enqueued attribute has a slightly different meaning for tasks and cpus:
331 * - task: the task's util_avg at last task dequeue time
332 * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU
333 * Thus, the util_est.enqueued of a task represents the contribution on the
334 * estimated utilization of the CPU where that task is currently enqueued.
336 * Only for tasks we track a moving average of the past instantaneous
337 * estimated utilization. This allows to absorb sporadic drops in utilization
338 * of an otherwise almost periodic task.
341 unsigned int enqueued;
343 #define UTIL_EST_WEIGHT_SHIFT 2
344 } __attribute__((__aligned__(sizeof(u64))));
347 * The load_avg/util_avg accumulates an infinite geometric series
348 * (see __update_load_avg() in kernel/sched/fair.c).
350 * [load_avg definition]
352 * load_avg = runnable% * scale_load_down(load)
354 * where runnable% is the time ratio that a sched_entity is runnable.
355 * For cfs_rq, it is the aggregated load_avg of all runnable and
356 * blocked sched_entities.
358 * load_avg may also take frequency scaling into account:
360 * load_avg = runnable% * scale_load_down(load) * freq%
362 * where freq% is the CPU frequency normalized to the highest frequency.
364 * [util_avg definition]
366 * util_avg = running% * SCHED_CAPACITY_SCALE
368 * where running% is the time ratio that a sched_entity is running on
369 * a CPU. For cfs_rq, it is the aggregated util_avg of all runnable
370 * and blocked sched_entities.
372 * util_avg may also factor frequency scaling and CPU capacity scaling:
374 * util_avg = running% * SCHED_CAPACITY_SCALE * freq% * capacity%
376 * where freq% is the same as above, and capacity% is the CPU capacity
377 * normalized to the greatest capacity (due to uarch differences, etc).
379 * N.B., the above ratios (runnable%, running%, freq%, and capacity%)
380 * themselves are in the range of [0, 1]. To do fixed point arithmetics,
381 * we therefore scale them to as large a range as necessary. This is for
382 * example reflected by util_avg's SCHED_CAPACITY_SCALE.
386 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
387 * with the highest load (=88761), always runnable on a single cfs_rq,
388 * and should not overflow as the number already hits PID_MAX_LIMIT.
390 * For all other cases (including 32-bit kernels), struct load_weight's
391 * weight will overflow first before we do, because:
393 * Max(load_avg) <= Max(load.weight)
395 * Then it is the load_weight's responsibility to consider overflow
399 u64 last_update_time;
401 u64 runnable_load_sum;
404 unsigned long load_avg;
405 unsigned long runnable_load_avg;
406 unsigned long util_avg;
407 struct util_est util_est;
408 } ____cacheline_aligned;
410 struct sched_statistics {
411 #ifdef CONFIG_SCHEDSTATS
421 s64 sum_sleep_runtime;
428 u64 nr_migrations_cold;
429 u64 nr_failed_migrations_affine;
430 u64 nr_failed_migrations_running;
431 u64 nr_failed_migrations_hot;
432 u64 nr_forced_migrations;
436 u64 nr_wakeups_migrate;
437 u64 nr_wakeups_local;
438 u64 nr_wakeups_remote;
439 u64 nr_wakeups_affine;
440 u64 nr_wakeups_affine_attempts;
441 u64 nr_wakeups_passive;
446 struct sched_entity {
447 /* For load-balancing: */
448 struct load_weight load;
449 unsigned long runnable_weight;
450 struct rb_node run_node;
451 struct list_head group_node;
455 u64 sum_exec_runtime;
457 u64 prev_sum_exec_runtime;
461 struct sched_statistics statistics;
463 #ifdef CONFIG_FAIR_GROUP_SCHED
465 struct sched_entity *parent;
466 /* rq on which this entity is (to be) queued: */
467 struct cfs_rq *cfs_rq;
468 /* rq "owned" by this entity/group: */
474 * Per entity load average tracking.
476 * Put into separate cache line so it does not
477 * collide with read-mostly values above.
479 struct sched_avg avg;
483 struct sched_rt_entity {
484 struct list_head run_list;
485 unsigned long timeout;
486 unsigned long watchdog_stamp;
487 unsigned int time_slice;
488 unsigned short on_rq;
489 unsigned short on_list;
491 struct sched_rt_entity *back;
492 #ifdef CONFIG_RT_GROUP_SCHED
493 struct sched_rt_entity *parent;
494 /* rq on which this entity is (to be) queued: */
496 /* rq "owned" by this entity/group: */
499 } __randomize_layout;
501 struct sched_dl_entity {
502 struct rb_node rb_node;
505 * Original scheduling parameters. Copied here from sched_attr
506 * during sched_setattr(), they will remain the same until
507 * the next sched_setattr().
509 u64 dl_runtime; /* Maximum runtime for each instance */
510 u64 dl_deadline; /* Relative deadline of each instance */
511 u64 dl_period; /* Separation of two instances (period) */
512 u64 dl_bw; /* dl_runtime / dl_period */
513 u64 dl_density; /* dl_runtime / dl_deadline */
516 * Actual scheduling parameters. Initialized with the values above,
517 * they are continously updated during task execution. Note that
518 * the remaining runtime could be < 0 in case we are in overrun.
520 s64 runtime; /* Remaining runtime for this instance */
521 u64 deadline; /* Absolute deadline for this instance */
522 unsigned int flags; /* Specifying the scheduler behaviour */
527 * @dl_throttled tells if we exhausted the runtime. If so, the
528 * task has to wait for a replenishment to be performed at the
529 * next firing of dl_timer.
531 * @dl_boosted tells if we are boosted due to DI. If so we are
532 * outside bandwidth enforcement mechanism (but only until we
533 * exit the critical section);
535 * @dl_yielded tells if task gave up the CPU before consuming
536 * all its available runtime during the last job.
538 * @dl_non_contending tells if the task is inactive while still
539 * contributing to the active utilization. In other words, it
540 * indicates if the inactive timer has been armed and its handler
541 * has not been executed yet. This flag is useful to avoid race
542 * conditions between the inactive timer handler and the wakeup
545 * @dl_overrun tells if the task asked to be informed about runtime
548 unsigned int dl_throttled : 1;
549 unsigned int dl_boosted : 1;
550 unsigned int dl_yielded : 1;
551 unsigned int dl_non_contending : 1;
552 unsigned int dl_overrun : 1;
555 * Bandwidth enforcement timer. Each -deadline task has its
556 * own bandwidth to be enforced, thus we need one timer per task.
558 struct hrtimer dl_timer;
561 * Inactive timer, responsible for decreasing the active utilization
562 * at the "0-lag time". When a -deadline task blocks, it contributes
563 * to GRUB's active utilization until the "0-lag time", hence a
564 * timer is needed to decrease the active utilization at the correct
567 struct hrtimer inactive_timer;
575 u16 s; /* Set of bits. */
578 enum perf_event_task_context {
579 perf_invalid_context = -1,
582 perf_nr_task_contexts,
586 struct wake_q_node *next;
590 #ifdef CONFIG_THREAD_INFO_IN_TASK
592 * For reasons of header soup (see current_thread_info()), this
593 * must be the first element of task_struct.
595 struct thread_info thread_info;
597 /* -1 unrunnable, 0 runnable, >0 stopped: */
601 * This begins the randomizable portion of task_struct. Only
602 * scheduling-critical items should be added above here.
604 randomized_struct_fields_start
608 /* Per task flags (PF_*), defined further below: */
613 struct llist_node wake_entry;
615 #ifdef CONFIG_THREAD_INFO_IN_TASK
619 unsigned int wakee_flips;
620 unsigned long wakee_flip_decay_ts;
621 struct task_struct *last_wakee;
624 * recent_used_cpu is initially set as the last CPU used by a task
625 * that wakes affine another task. Waker/wakee relationships can
626 * push tasks around a CPU where each wakeup moves to the next one.
627 * Tracking a recently used CPU allows a quick search for a recently
628 * used CPU that may be idle.
638 unsigned int rt_priority;
640 const struct sched_class *sched_class;
641 struct sched_entity se;
642 struct sched_rt_entity rt;
643 #ifdef CONFIG_CGROUP_SCHED
644 struct task_group *sched_task_group;
646 struct sched_dl_entity dl;
648 #ifdef CONFIG_PREEMPT_NOTIFIERS
649 /* List of struct preempt_notifier: */
650 struct hlist_head preempt_notifiers;
653 #ifdef CONFIG_BLK_DEV_IO_TRACE
654 unsigned int btrace_seq;
659 cpumask_t cpus_allowed;
661 #ifdef CONFIG_PREEMPT_RCU
662 int rcu_read_lock_nesting;
663 union rcu_special rcu_read_unlock_special;
664 struct list_head rcu_node_entry;
665 struct rcu_node *rcu_blocked_node;
666 #endif /* #ifdef CONFIG_PREEMPT_RCU */
668 #ifdef CONFIG_TASKS_RCU
669 unsigned long rcu_tasks_nvcsw;
670 u8 rcu_tasks_holdout;
672 int rcu_tasks_idle_cpu;
673 struct list_head rcu_tasks_holdout_list;
674 #endif /* #ifdef CONFIG_TASKS_RCU */
676 struct sched_info sched_info;
678 struct list_head tasks;
680 struct plist_node pushable_tasks;
681 struct rb_node pushable_dl_tasks;
684 struct mm_struct *mm;
685 struct mm_struct *active_mm;
687 /* Per-thread vma caching: */
688 struct vmacache vmacache;
690 #ifdef SPLIT_RSS_COUNTING
691 struct task_rss_stat rss_stat;
696 /* The signal sent when the parent dies: */
698 /* JOBCTL_*, siglock protected: */
699 unsigned long jobctl;
701 /* Used for emulating ABI behavior of previous Linux versions: */
702 unsigned int personality;
704 /* Scheduler bits, serialized by scheduler locks: */
705 unsigned sched_reset_on_fork:1;
706 unsigned sched_contributes_to_load:1;
707 unsigned sched_migrated:1;
708 unsigned sched_remote_wakeup:1;
709 /* Force alignment to the next boundary: */
712 /* Unserialized, strictly 'current' */
714 /* Bit to tell LSMs we're in execve(): */
715 unsigned in_execve:1;
716 unsigned in_iowait:1;
717 #ifndef TIF_RESTORE_SIGMASK
718 unsigned restore_sigmask:1;
721 unsigned in_user_fault:1;
722 #ifdef CONFIG_MEMCG_KMEM
723 unsigned memcg_kmem_skip_account:1;
726 #ifdef CONFIG_COMPAT_BRK
727 unsigned brk_randomized:1;
729 #ifdef CONFIG_CGROUPS
730 /* disallow userland-initiated cgroup migration */
731 unsigned no_cgroup_migration:1;
733 #ifdef CONFIG_BLK_CGROUP
734 /* to be used once the psi infrastructure lands upstream. */
735 unsigned use_memdelay:1;
739 * May usercopy functions fault on kernel addresses?
740 * This is not just a single bit because this can potentially nest.
742 unsigned int kernel_uaccess_faults_ok;
744 unsigned long atomic_flags; /* Flags requiring atomic access. */
746 struct restart_block restart_block;
751 #ifdef CONFIG_STACKPROTECTOR
752 /* Canary value for the -fstack-protector GCC feature: */
753 unsigned long stack_canary;
756 * Pointers to the (original) parent process, youngest child, younger sibling,
757 * older sibling, respectively. (p->father can be replaced with
758 * p->real_parent->pid)
761 /* Real parent process: */
762 struct task_struct __rcu *real_parent;
764 /* Recipient of SIGCHLD, wait4() reports: */
765 struct task_struct __rcu *parent;
768 * Children/sibling form the list of natural children:
770 struct list_head children;
771 struct list_head sibling;
772 struct task_struct *group_leader;
775 * 'ptraced' is the list of tasks this task is using ptrace() on.
777 * This includes both natural children and PTRACE_ATTACH targets.
778 * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
780 struct list_head ptraced;
781 struct list_head ptrace_entry;
783 /* PID/PID hash table linkage. */
784 struct pid *thread_pid;
785 struct hlist_node pid_links[PIDTYPE_MAX];
786 struct list_head thread_group;
787 struct list_head thread_node;
789 struct completion *vfork_done;
791 /* CLONE_CHILD_SETTID: */
792 int __user *set_child_tid;
794 /* CLONE_CHILD_CLEARTID: */
795 int __user *clear_child_tid;
799 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
804 struct prev_cputime prev_cputime;
805 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
809 #ifdef CONFIG_NO_HZ_FULL
810 atomic_t tick_dep_mask;
812 /* Context switch counts: */
814 unsigned long nivcsw;
816 /* Monotonic time in nsecs: */
819 /* Boot based time in nsecs: */
822 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
823 unsigned long min_flt;
824 unsigned long maj_flt;
826 #ifdef CONFIG_POSIX_TIMERS
827 struct task_cputime cputime_expires;
828 struct list_head cpu_timers[3];
831 /* Process credentials: */
833 /* Tracer's credentials at attach: */
834 const struct cred __rcu *ptracer_cred;
836 /* Objective and real subjective task credentials (COW): */
837 const struct cred __rcu *real_cred;
839 /* Effective (overridable) subjective task credentials (COW): */
840 const struct cred __rcu *cred;
843 * executable name, excluding path.
845 * - normally initialized setup_new_exec()
846 * - access it with [gs]et_task_comm()
847 * - lock it with task_lock()
849 char comm[TASK_COMM_LEN];
851 struct nameidata *nameidata;
853 #ifdef CONFIG_SYSVIPC
854 struct sysv_sem sysvsem;
855 struct sysv_shm sysvshm;
857 #ifdef CONFIG_DETECT_HUNG_TASK
858 unsigned long last_switch_count;
859 unsigned long last_switch_time;
861 /* Filesystem information: */
862 struct fs_struct *fs;
864 /* Open file information: */
865 struct files_struct *files;
868 struct nsproxy *nsproxy;
870 /* Signal handlers: */
871 struct signal_struct *signal;
872 struct sighand_struct *sighand;
874 sigset_t real_blocked;
875 /* Restored if set_restore_sigmask() was used: */
876 sigset_t saved_sigmask;
877 struct sigpending pending;
878 unsigned long sas_ss_sp;
880 unsigned int sas_ss_flags;
882 struct callback_head *task_works;
884 struct audit_context *audit_context;
885 #ifdef CONFIG_AUDITSYSCALL
887 unsigned int sessionid;
889 struct seccomp seccomp;
891 /* Thread group tracking: */
895 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
896 spinlock_t alloc_lock;
898 /* Protection of the PI data structures: */
899 raw_spinlock_t pi_lock;
901 struct wake_q_node wake_q;
903 #ifdef CONFIG_RT_MUTEXES
904 /* PI waiters blocked on a rt_mutex held by this task: */
905 struct rb_root_cached pi_waiters;
906 /* Updated under owner's pi_lock and rq lock */
907 struct task_struct *pi_top_task;
908 /* Deadlock detection and priority inheritance handling: */
909 struct rt_mutex_waiter *pi_blocked_on;
912 #ifdef CONFIG_DEBUG_MUTEXES
913 /* Mutex deadlock detection: */
914 struct mutex_waiter *blocked_on;
917 #ifdef CONFIG_TRACE_IRQFLAGS
918 unsigned int irq_events;
919 unsigned long hardirq_enable_ip;
920 unsigned long hardirq_disable_ip;
921 unsigned int hardirq_enable_event;
922 unsigned int hardirq_disable_event;
923 int hardirqs_enabled;
925 unsigned long softirq_disable_ip;
926 unsigned long softirq_enable_ip;
927 unsigned int softirq_disable_event;
928 unsigned int softirq_enable_event;
929 int softirqs_enabled;
933 #ifdef CONFIG_LOCKDEP
934 # define MAX_LOCK_DEPTH 48UL
937 unsigned int lockdep_recursion;
938 struct held_lock held_locks[MAX_LOCK_DEPTH];
942 unsigned int in_ubsan;
945 /* Journalling filesystem info: */
948 /* Stacked block device info: */
949 struct bio_list *bio_list;
952 /* Stack plugging: */
953 struct blk_plug *plug;
957 struct reclaim_state *reclaim_state;
959 struct backing_dev_info *backing_dev_info;
961 struct io_context *io_context;
964 unsigned long ptrace_message;
965 siginfo_t *last_siginfo;
967 struct task_io_accounting ioac;
968 #ifdef CONFIG_TASK_XACCT
969 /* Accumulated RSS usage: */
971 /* Accumulated virtual memory usage: */
973 /* stime + utime since last update: */
976 #ifdef CONFIG_CPUSETS
977 /* Protected by ->alloc_lock: */
978 nodemask_t mems_allowed;
979 /* Seqence number to catch updates: */
980 seqcount_t mems_allowed_seq;
981 int cpuset_mem_spread_rotor;
982 int cpuset_slab_spread_rotor;
984 #ifdef CONFIG_CGROUPS
985 /* Control Group info protected by css_set_lock: */
986 struct css_set __rcu *cgroups;
987 /* cg_list protected by css_set_lock and tsk->alloc_lock: */
988 struct list_head cg_list;
990 #ifdef CONFIG_INTEL_RDT
995 struct robust_list_head __user *robust_list;
997 struct compat_robust_list_head __user *compat_robust_list;
999 struct list_head pi_state_list;
1000 struct futex_pi_state *pi_state_cache;
1002 #ifdef CONFIG_PERF_EVENTS
1003 struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1004 struct mutex perf_event_mutex;
1005 struct list_head perf_event_list;
1007 #ifdef CONFIG_DEBUG_PREEMPT
1008 unsigned long preempt_disable_ip;
1011 /* Protected by alloc_lock: */
1012 struct mempolicy *mempolicy;
1014 short pref_node_fork;
1016 #ifdef CONFIG_NUMA_BALANCING
1018 unsigned int numa_scan_period;
1019 unsigned int numa_scan_period_max;
1020 int numa_preferred_nid;
1021 unsigned long numa_migrate_retry;
1022 /* Migration stamp: */
1024 u64 last_task_numa_placement;
1025 u64 last_sum_exec_runtime;
1026 struct callback_head numa_work;
1028 struct numa_group *numa_group;
1031 * numa_faults is an array split into four regions:
1032 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1033 * in this precise order.
1035 * faults_memory: Exponential decaying average of faults on a per-node
1036 * basis. Scheduling placement decisions are made based on these
1037 * counts. The values remain static for the duration of a PTE scan.
1038 * faults_cpu: Track the nodes the process was running on when a NUMA
1039 * hinting fault was incurred.
1040 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1041 * during the current scan window. When the scan completes, the counts
1042 * in faults_memory and faults_cpu decay and these values are copied.
1044 unsigned long *numa_faults;
1045 unsigned long total_numa_faults;
1048 * numa_faults_locality tracks if faults recorded during the last
1049 * scan window were remote/local or failed to migrate. The task scan
1050 * period is adapted based on the locality of the faults with different
1051 * weights depending on whether they were shared or private faults
1053 unsigned long numa_faults_locality[3];
1055 unsigned long numa_pages_migrated;
1056 #endif /* CONFIG_NUMA_BALANCING */
1059 struct rseq __user *rseq;
1063 * RmW on rseq_event_mask must be performed atomically
1064 * with respect to preemption.
1066 unsigned long rseq_event_mask;
1069 struct tlbflush_unmap_batch tlb_ubc;
1071 struct rcu_head rcu;
1073 /* Cache last used pipe for splice(): */
1074 struct pipe_inode_info *splice_pipe;
1076 struct page_frag task_frag;
1078 #ifdef CONFIG_TASK_DELAY_ACCT
1079 struct task_delay_info *delays;
1082 #ifdef CONFIG_FAULT_INJECTION
1084 unsigned int fail_nth;
1087 * When (nr_dirtied >= nr_dirtied_pause), it's time to call
1088 * balance_dirty_pages() for a dirty throttling pause:
1091 int nr_dirtied_pause;
1092 /* Start of a write-and-pause period: */
1093 unsigned long dirty_paused_when;
1095 #ifdef CONFIG_LATENCYTOP
1096 int latency_record_count;
1097 struct latency_record latency_record[LT_SAVECOUNT];
1100 * Time slack values; these are used to round up poll() and
1101 * select() etc timeout values. These are in nanoseconds.
1104 u64 default_timer_slack_ns;
1107 unsigned int kasan_depth;
1110 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1111 /* Index of current stored address in ret_stack: */
1114 /* Stack of return addresses for return function tracing: */
1115 struct ftrace_ret_stack *ret_stack;
1117 /* Timestamp for last schedule: */
1118 unsigned long long ftrace_timestamp;
1121 * Number of functions that haven't been traced
1122 * because of depth overrun:
1124 atomic_t trace_overrun;
1126 /* Pause tracing: */
1127 atomic_t tracing_graph_pause;
1130 #ifdef CONFIG_TRACING
1131 /* State flags for use by tracers: */
1132 unsigned long trace;
1134 /* Bitmask and counter of trace recursion: */
1135 unsigned long trace_recursion;
1136 #endif /* CONFIG_TRACING */
1139 /* Coverage collection mode enabled for this task (0 if disabled): */
1140 unsigned int kcov_mode;
1142 /* Size of the kcov_area: */
1143 unsigned int kcov_size;
1145 /* Buffer for coverage collection: */
1148 /* KCOV descriptor wired with this task or NULL: */
1153 struct mem_cgroup *memcg_in_oom;
1154 gfp_t memcg_oom_gfp_mask;
1155 int memcg_oom_order;
1157 /* Number of pages to reclaim on returning to userland: */
1158 unsigned int memcg_nr_pages_over_high;
1160 /* Used by memcontrol for targeted memcg charge: */
1161 struct mem_cgroup *active_memcg;
1164 #ifdef CONFIG_BLK_CGROUP
1165 struct request_queue *throttle_queue;
1168 #ifdef CONFIG_UPROBES
1169 struct uprobe_task *utask;
1171 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1172 unsigned int sequential_io;
1173 unsigned int sequential_io_avg;
1175 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1176 unsigned long task_state_change;
1178 int pagefault_disabled;
1180 struct task_struct *oom_reaper_list;
1182 #ifdef CONFIG_VMAP_STACK
1183 struct vm_struct *stack_vm_area;
1185 #ifdef CONFIG_THREAD_INFO_IN_TASK
1186 /* A live task holds one reference: */
1187 atomic_t stack_refcount;
1189 #ifdef CONFIG_LIVEPATCH
1192 #ifdef CONFIG_SECURITY
1193 /* Used by LSM modules for access restriction: */
1198 * New fields for task_struct should be added above here, so that
1199 * they are included in the randomized portion of task_struct.
1201 randomized_struct_fields_end
1203 /* CPU-specific state of this task: */
1204 struct thread_struct thread;
1207 * WARNING: on x86, 'thread_struct' contains a variable-sized
1208 * structure. It *MUST* be at the end of 'task_struct'.
1210 * Do not put anything below here!
1214 static inline struct pid *task_pid(struct task_struct *task)
1216 return task->thread_pid;
1220 * the helpers to get the task's different pids as they are seen
1221 * from various namespaces
1223 * task_xid_nr() : global id, i.e. the id seen from the init namespace;
1224 * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of
1226 * task_xid_nr_ns() : id seen from the ns specified;
1228 * see also pid_nr() etc in include/linux/pid.h
1230 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns);
1232 static inline pid_t task_pid_nr(struct task_struct *tsk)
1237 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1239 return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1242 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1244 return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1248 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1254 * pid_alive - check that a task structure is not stale
1255 * @p: Task structure to be checked.
1257 * Test if a process is not yet dead (at most zombie state)
1258 * If pid_alive fails, then pointers within the task structure
1259 * can be stale and must not be dereferenced.
1261 * Return: 1 if the process is alive. 0 otherwise.
1263 static inline int pid_alive(const struct task_struct *p)
1265 return p->thread_pid != NULL;
1268 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1270 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1273 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1275 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1279 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1281 return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1284 static inline pid_t task_session_vnr(struct task_struct *tsk)
1286 return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1289 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1291 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, ns);
1294 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1296 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, NULL);
1299 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1305 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1311 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1313 return task_ppid_nr_ns(tsk, &init_pid_ns);
1316 /* Obsolete, do not use: */
1317 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1319 return task_pgrp_nr_ns(tsk, &init_pid_ns);
1322 #define TASK_REPORT_IDLE (TASK_REPORT + 1)
1323 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1)
1325 static inline unsigned int task_state_index(struct task_struct *tsk)
1327 unsigned int tsk_state = READ_ONCE(tsk->state);
1328 unsigned int state = (tsk_state | tsk->exit_state) & TASK_REPORT;
1330 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX);
1332 if (tsk_state == TASK_IDLE)
1333 state = TASK_REPORT_IDLE;
1338 static inline char task_index_to_char(unsigned int state)
1340 static const char state_char[] = "RSDTtXZPI";
1342 BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1);
1344 return state_char[state];
1347 static inline char task_state_to_char(struct task_struct *tsk)
1349 return task_index_to_char(task_state_index(tsk));
1353 * is_global_init - check if a task structure is init. Since init
1354 * is free to have sub-threads we need to check tgid.
1355 * @tsk: Task structure to be checked.
1357 * Check if a task structure is the first user space task the kernel created.
1359 * Return: 1 if the task structure is init. 0 otherwise.
1361 static inline int is_global_init(struct task_struct *tsk)
1363 return task_tgid_nr(tsk) == 1;
1366 extern struct pid *cad_pid;
1371 #define PF_IDLE 0x00000002 /* I am an IDLE thread */
1372 #define PF_EXITING 0x00000004 /* Getting shut down */
1373 #define PF_EXITPIDONE 0x00000008 /* PI exit done on shut down */
1374 #define PF_VCPU 0x00000010 /* I'm a virtual CPU */
1375 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */
1376 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */
1377 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */
1378 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */
1379 #define PF_DUMPCORE 0x00000200 /* Dumped core */
1380 #define PF_SIGNALED 0x00000400 /* Killed by a signal */
1381 #define PF_MEMALLOC 0x00000800 /* Allocating memory */
1382 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */
1383 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */
1384 #define PF_USED_ASYNC 0x00004000 /* Used async_schedule*(), used by module init */
1385 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */
1386 #define PF_FROZEN 0x00010000 /* Frozen for system suspend */
1387 #define PF_KSWAPD 0x00020000 /* I am kswapd */
1388 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocation requests will inherit GFP_NOFS */
1389 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocation requests will inherit GFP_NOIO */
1390 #define PF_LESS_THROTTLE 0x00100000 /* Throttle me less: I clean memory */
1391 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */
1392 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */
1393 #define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */
1394 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_allowed */
1395 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */
1396 #define PF_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */
1397 #define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezable */
1398 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */
1401 * Only the _current_ task can read/write to tsk->flags, but other
1402 * tasks can access tsk->flags in readonly mode for example
1403 * with tsk_used_math (like during threaded core dumping).
1404 * There is however an exception to this rule during ptrace
1405 * or during fork: the ptracer task is allowed to write to the
1406 * child->flags of its traced child (same goes for fork, the parent
1407 * can write to the child->flags), because we're guaranteed the
1408 * child is not running and in turn not changing child->flags
1409 * at the same time the parent does it.
1411 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1412 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1413 #define clear_used_math() clear_stopped_child_used_math(current)
1414 #define set_used_math() set_stopped_child_used_math(current)
1416 #define conditional_stopped_child_used_math(condition, child) \
1417 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1419 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current)
1421 #define copy_to_stopped_child_used_math(child) \
1422 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1424 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1425 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1426 #define used_math() tsk_used_math(current)
1428 static inline bool is_percpu_thread(void)
1431 return (current->flags & PF_NO_SETAFFINITY) &&
1432 (current->nr_cpus_allowed == 1);
1438 /* Per-process atomic flags. */
1439 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */
1440 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */
1441 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */
1442 #define PFA_SPEC_SSB_DISABLE 3 /* Speculative Store Bypass disabled */
1443 #define PFA_SPEC_SSB_FORCE_DISABLE 4 /* Speculative Store Bypass force disabled*/
1445 #define TASK_PFA_TEST(name, func) \
1446 static inline bool task_##func(struct task_struct *p) \
1447 { return test_bit(PFA_##name, &p->atomic_flags); }
1449 #define TASK_PFA_SET(name, func) \
1450 static inline void task_set_##func(struct task_struct *p) \
1451 { set_bit(PFA_##name, &p->atomic_flags); }
1453 #define TASK_PFA_CLEAR(name, func) \
1454 static inline void task_clear_##func(struct task_struct *p) \
1455 { clear_bit(PFA_##name, &p->atomic_flags); }
1457 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
1458 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
1460 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
1461 TASK_PFA_SET(SPREAD_PAGE, spread_page)
1462 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
1464 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
1465 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
1466 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
1468 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable)
1469 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable)
1470 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable)
1472 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1473 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1476 current_restore_flags(unsigned long orig_flags, unsigned long flags)
1478 current->flags &= ~flags;
1479 current->flags |= orig_flags & flags;
1482 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
1483 extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed);
1485 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
1486 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
1488 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
1491 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
1493 if (!cpumask_test_cpu(0, new_mask))
1499 #ifndef cpu_relax_yield
1500 #define cpu_relax_yield() cpu_relax()
1503 extern int yield_to(struct task_struct *p, bool preempt);
1504 extern void set_user_nice(struct task_struct *p, long nice);
1505 extern int task_prio(const struct task_struct *p);
1508 * task_nice - return the nice value of a given task.
1509 * @p: the task in question.
1511 * Return: The nice value [ -20 ... 0 ... 19 ].
1513 static inline int task_nice(const struct task_struct *p)
1515 return PRIO_TO_NICE((p)->static_prio);
1518 extern int can_nice(const struct task_struct *p, const int nice);
1519 extern int task_curr(const struct task_struct *p);
1520 extern int idle_cpu(int cpu);
1521 extern int available_idle_cpu(int cpu);
1522 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *);
1523 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *);
1524 extern int sched_setattr(struct task_struct *, const struct sched_attr *);
1525 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *);
1526 extern struct task_struct *idle_task(int cpu);
1529 * is_idle_task - is the specified task an idle task?
1530 * @p: the task in question.
1532 * Return: 1 if @p is an idle task. 0 otherwise.
1534 static inline bool is_idle_task(const struct task_struct *p)
1536 return !!(p->flags & PF_IDLE);
1539 extern struct task_struct *curr_task(int cpu);
1540 extern void ia64_set_curr_task(int cpu, struct task_struct *p);
1544 union thread_union {
1545 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK
1546 struct task_struct task;
1548 #ifndef CONFIG_THREAD_INFO_IN_TASK
1549 struct thread_info thread_info;
1551 unsigned long stack[THREAD_SIZE/sizeof(long)];
1554 #ifndef CONFIG_THREAD_INFO_IN_TASK
1555 extern struct thread_info init_thread_info;
1558 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
1560 #ifdef CONFIG_THREAD_INFO_IN_TASK
1561 static inline struct thread_info *task_thread_info(struct task_struct *task)
1563 return &task->thread_info;
1565 #elif !defined(__HAVE_THREAD_FUNCTIONS)
1566 # define task_thread_info(task) ((struct thread_info *)(task)->stack)
1570 * find a task by one of its numerical ids
1572 * find_task_by_pid_ns():
1573 * finds a task by its pid in the specified namespace
1574 * find_task_by_vpid():
1575 * finds a task by its virtual pid
1577 * see also find_vpid() etc in include/linux/pid.h
1580 extern struct task_struct *find_task_by_vpid(pid_t nr);
1581 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns);
1584 * find a task by its virtual pid and get the task struct
1586 extern struct task_struct *find_get_task_by_vpid(pid_t nr);
1588 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
1589 extern int wake_up_process(struct task_struct *tsk);
1590 extern void wake_up_new_task(struct task_struct *tsk);
1593 extern void kick_process(struct task_struct *tsk);
1595 static inline void kick_process(struct task_struct *tsk) { }
1598 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
1600 static inline void set_task_comm(struct task_struct *tsk, const char *from)
1602 __set_task_comm(tsk, from, false);
1605 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk);
1606 #define get_task_comm(buf, tsk) ({ \
1607 BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN); \
1608 __get_task_comm(buf, sizeof(buf), tsk); \
1612 void scheduler_ipi(void);
1613 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
1615 static inline void scheduler_ipi(void) { }
1616 static inline unsigned long wait_task_inactive(struct task_struct *p, long match_state)
1623 * Set thread flags in other task's structures.
1624 * See asm/thread_info.h for TIF_xxxx flags available:
1626 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
1628 set_ti_thread_flag(task_thread_info(tsk), flag);
1631 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1633 clear_ti_thread_flag(task_thread_info(tsk), flag);
1636 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag,
1639 update_ti_thread_flag(task_thread_info(tsk), flag, value);
1642 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
1644 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
1647 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1649 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
1652 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
1654 return test_ti_thread_flag(task_thread_info(tsk), flag);
1657 static inline void set_tsk_need_resched(struct task_struct *tsk)
1659 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1662 static inline void clear_tsk_need_resched(struct task_struct *tsk)
1664 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1667 static inline int test_tsk_need_resched(struct task_struct *tsk)
1669 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
1673 * cond_resched() and cond_resched_lock(): latency reduction via
1674 * explicit rescheduling in places that are safe. The return
1675 * value indicates whether a reschedule was done in fact.
1676 * cond_resched_lock() will drop the spinlock before scheduling,
1678 #ifndef CONFIG_PREEMPT
1679 extern int _cond_resched(void);
1681 static inline int _cond_resched(void) { return 0; }
1684 #define cond_resched() ({ \
1685 ___might_sleep(__FILE__, __LINE__, 0); \
1689 extern int __cond_resched_lock(spinlock_t *lock);
1691 #define cond_resched_lock(lock) ({ \
1692 ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
1693 __cond_resched_lock(lock); \
1696 static inline void cond_resched_rcu(void)
1698 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
1706 * Does a critical section need to be broken due to another
1707 * task waiting?: (technically does not depend on CONFIG_PREEMPT,
1708 * but a general need for low latency)
1710 static inline int spin_needbreak(spinlock_t *lock)
1712 #ifdef CONFIG_PREEMPT
1713 return spin_is_contended(lock);
1719 static __always_inline bool need_resched(void)
1721 return unlikely(tif_need_resched());
1725 * Wrappers for p->thread_info->cpu access. No-op on UP.
1729 static inline unsigned int task_cpu(const struct task_struct *p)
1731 #ifdef CONFIG_THREAD_INFO_IN_TASK
1734 return task_thread_info(p)->cpu;
1738 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
1742 static inline unsigned int task_cpu(const struct task_struct *p)
1747 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
1751 #endif /* CONFIG_SMP */
1754 * In order to reduce various lock holder preemption latencies provide an
1755 * interface to see if a vCPU is currently running or not.
1757 * This allows us to terminate optimistic spin loops and block, analogous to
1758 * the native optimistic spin heuristic of testing if the lock owner task is
1761 #ifndef vcpu_is_preempted
1762 # define vcpu_is_preempted(cpu) false
1765 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
1766 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
1768 #ifndef TASK_SIZE_OF
1769 #define TASK_SIZE_OF(tsk) TASK_SIZE
1775 * Map the event mask on the user-space ABI enum rseq_cs_flags
1776 * for direct mask checks.
1778 enum rseq_event_mask_bits {
1779 RSEQ_EVENT_PREEMPT_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT,
1780 RSEQ_EVENT_SIGNAL_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT,
1781 RSEQ_EVENT_MIGRATE_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT,
1784 enum rseq_event_mask {
1785 RSEQ_EVENT_PREEMPT = (1U << RSEQ_EVENT_PREEMPT_BIT),
1786 RSEQ_EVENT_SIGNAL = (1U << RSEQ_EVENT_SIGNAL_BIT),
1787 RSEQ_EVENT_MIGRATE = (1U << RSEQ_EVENT_MIGRATE_BIT),
1790 static inline void rseq_set_notify_resume(struct task_struct *t)
1793 set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
1796 void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs);
1798 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
1799 struct pt_regs *regs)
1802 __rseq_handle_notify_resume(ksig, regs);
1805 static inline void rseq_signal_deliver(struct ksignal *ksig,
1806 struct pt_regs *regs)
1809 __set_bit(RSEQ_EVENT_SIGNAL_BIT, ¤t->rseq_event_mask);
1811 rseq_handle_notify_resume(ksig, regs);
1814 /* rseq_preempt() requires preemption to be disabled. */
1815 static inline void rseq_preempt(struct task_struct *t)
1817 __set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask);
1818 rseq_set_notify_resume(t);
1821 /* rseq_migrate() requires preemption to be disabled. */
1822 static inline void rseq_migrate(struct task_struct *t)
1824 __set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask);
1825 rseq_set_notify_resume(t);
1829 * If parent process has a registered restartable sequences area, the
1830 * child inherits. Only applies when forking a process, not a thread.
1832 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
1834 if (clone_flags & CLONE_THREAD) {
1838 t->rseq_event_mask = 0;
1840 t->rseq = current->rseq;
1841 t->rseq_len = current->rseq_len;
1842 t->rseq_sig = current->rseq_sig;
1843 t->rseq_event_mask = current->rseq_event_mask;
1847 static inline void rseq_execve(struct task_struct *t)
1852 t->rseq_event_mask = 0;
1857 static inline void rseq_set_notify_resume(struct task_struct *t)
1860 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
1861 struct pt_regs *regs)
1864 static inline void rseq_signal_deliver(struct ksignal *ksig,
1865 struct pt_regs *regs)
1868 static inline void rseq_preempt(struct task_struct *t)
1871 static inline void rseq_migrate(struct task_struct *t)
1874 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
1877 static inline void rseq_execve(struct task_struct *t)
1883 #ifdef CONFIG_DEBUG_RSEQ
1885 void rseq_syscall(struct pt_regs *regs);
1889 static inline void rseq_syscall(struct pt_regs *regs)