ipv6: tcp: add rcu locking in tcp_v6_send_synack()
[deliverable/linux.git] / include / linux / sched.h
... / ...
CommitLineData
1#ifndef _LINUX_SCHED_H
2#define _LINUX_SCHED_H
3
4#include <uapi/linux/sched.h>
5
6#include <linux/sched/prio.h>
7
8
9struct sched_param {
10 int sched_priority;
11};
12
13#include <asm/param.h> /* for HZ */
14
15#include <linux/capability.h>
16#include <linux/threads.h>
17#include <linux/kernel.h>
18#include <linux/types.h>
19#include <linux/timex.h>
20#include <linux/jiffies.h>
21#include <linux/plist.h>
22#include <linux/rbtree.h>
23#include <linux/thread_info.h>
24#include <linux/cpumask.h>
25#include <linux/errno.h>
26#include <linux/nodemask.h>
27#include <linux/mm_types.h>
28#include <linux/preempt.h>
29
30#include <asm/page.h>
31#include <asm/ptrace.h>
32#include <linux/cputime.h>
33
34#include <linux/smp.h>
35#include <linux/sem.h>
36#include <linux/shm.h>
37#include <linux/signal.h>
38#include <linux/compiler.h>
39#include <linux/completion.h>
40#include <linux/pid.h>
41#include <linux/percpu.h>
42#include <linux/topology.h>
43#include <linux/proportions.h>
44#include <linux/seccomp.h>
45#include <linux/rcupdate.h>
46#include <linux/rculist.h>
47#include <linux/rtmutex.h>
48
49#include <linux/time.h>
50#include <linux/param.h>
51#include <linux/resource.h>
52#include <linux/timer.h>
53#include <linux/hrtimer.h>
54#include <linux/task_io_accounting.h>
55#include <linux/latencytop.h>
56#include <linux/cred.h>
57#include <linux/llist.h>
58#include <linux/uidgid.h>
59#include <linux/gfp.h>
60#include <linux/magic.h>
61#include <linux/cgroup-defs.h>
62
63#include <asm/processor.h>
64
65#define SCHED_ATTR_SIZE_VER0 48 /* sizeof first published struct */
66
67/*
68 * Extended scheduling parameters data structure.
69 *
70 * This is needed because the original struct sched_param can not be
71 * altered without introducing ABI issues with legacy applications
72 * (e.g., in sched_getparam()).
73 *
74 * However, the possibility of specifying more than just a priority for
75 * the tasks may be useful for a wide variety of application fields, e.g.,
76 * multimedia, streaming, automation and control, and many others.
77 *
78 * This variant (sched_attr) is meant at describing a so-called
79 * sporadic time-constrained task. In such model a task is specified by:
80 * - the activation period or minimum instance inter-arrival time;
81 * - the maximum (or average, depending on the actual scheduling
82 * discipline) computation time of all instances, a.k.a. runtime;
83 * - the deadline (relative to the actual activation time) of each
84 * instance.
85 * Very briefly, a periodic (sporadic) task asks for the execution of
86 * some specific computation --which is typically called an instance--
87 * (at most) every period. Moreover, each instance typically lasts no more
88 * than the runtime and must be completed by time instant t equal to
89 * the instance activation time + the deadline.
90 *
91 * This is reflected by the actual fields of the sched_attr structure:
92 *
93 * @size size of the structure, for fwd/bwd compat.
94 *
95 * @sched_policy task's scheduling policy
96 * @sched_flags for customizing the scheduler behaviour
97 * @sched_nice task's nice value (SCHED_NORMAL/BATCH)
98 * @sched_priority task's static priority (SCHED_FIFO/RR)
99 * @sched_deadline representative of the task's deadline
100 * @sched_runtime representative of the task's runtime
101 * @sched_period representative of the task's period
102 *
103 * Given this task model, there are a multiplicity of scheduling algorithms
104 * and policies, that can be used to ensure all the tasks will make their
105 * timing constraints.
106 *
107 * As of now, the SCHED_DEADLINE policy (sched_dl scheduling class) is the
108 * only user of this new interface. More information about the algorithm
109 * available in the scheduling class file or in Documentation/.
110 */
111struct sched_attr {
112 u32 size;
113
114 u32 sched_policy;
115 u64 sched_flags;
116
117 /* SCHED_NORMAL, SCHED_BATCH */
118 s32 sched_nice;
119
120 /* SCHED_FIFO, SCHED_RR */
121 u32 sched_priority;
122
123 /* SCHED_DEADLINE */
124 u64 sched_runtime;
125 u64 sched_deadline;
126 u64 sched_period;
127};
128
129struct futex_pi_state;
130struct robust_list_head;
131struct bio_list;
132struct fs_struct;
133struct perf_event_context;
134struct blk_plug;
135struct filename;
136struct nameidata;
137
138#define VMACACHE_BITS 2
139#define VMACACHE_SIZE (1U << VMACACHE_BITS)
140#define VMACACHE_MASK (VMACACHE_SIZE - 1)
141
142/*
143 * These are the constant used to fake the fixed-point load-average
144 * counting. Some notes:
145 * - 11 bit fractions expand to 22 bits by the multiplies: this gives
146 * a load-average precision of 10 bits integer + 11 bits fractional
147 * - if you want to count load-averages more often, you need more
148 * precision, or rounding will get you. With 2-second counting freq,
149 * the EXP_n values would be 1981, 2034 and 2043 if still using only
150 * 11 bit fractions.
151 */
152extern unsigned long avenrun[]; /* Load averages */
153extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
154
155#define FSHIFT 11 /* nr of bits of precision */
156#define FIXED_1 (1<<FSHIFT) /* 1.0 as fixed-point */
157#define LOAD_FREQ (5*HZ+1) /* 5 sec intervals */
158#define EXP_1 1884 /* 1/exp(5sec/1min) as fixed-point */
159#define EXP_5 2014 /* 1/exp(5sec/5min) */
160#define EXP_15 2037 /* 1/exp(5sec/15min) */
161
162#define CALC_LOAD(load,exp,n) \
163 load *= exp; \
164 load += n*(FIXED_1-exp); \
165 load >>= FSHIFT;
166
167extern unsigned long total_forks;
168extern int nr_threads;
169DECLARE_PER_CPU(unsigned long, process_counts);
170extern int nr_processes(void);
171extern unsigned long nr_running(void);
172extern bool single_task_running(void);
173extern unsigned long nr_iowait(void);
174extern unsigned long nr_iowait_cpu(int cpu);
175extern void get_iowait_load(unsigned long *nr_waiters, unsigned long *load);
176
177extern void calc_global_load(unsigned long ticks);
178
179#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
180extern void update_cpu_load_nohz(void);
181#else
182static inline void update_cpu_load_nohz(void) { }
183#endif
184
185extern unsigned long get_parent_ip(unsigned long addr);
186
187extern void dump_cpu_task(int cpu);
188
189struct seq_file;
190struct cfs_rq;
191struct task_group;
192#ifdef CONFIG_SCHED_DEBUG
193extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
194extern void proc_sched_set_task(struct task_struct *p);
195#endif
196
197/*
198 * Task state bitmask. NOTE! These bits are also
199 * encoded in fs/proc/array.c: get_task_state().
200 *
201 * We have two separate sets of flags: task->state
202 * is about runnability, while task->exit_state are
203 * about the task exiting. Confusing, but this way
204 * modifying one set can't modify the other one by
205 * mistake.
206 */
207#define TASK_RUNNING 0
208#define TASK_INTERRUPTIBLE 1
209#define TASK_UNINTERRUPTIBLE 2
210#define __TASK_STOPPED 4
211#define __TASK_TRACED 8
212/* in tsk->exit_state */
213#define EXIT_DEAD 16
214#define EXIT_ZOMBIE 32
215#define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD)
216/* in tsk->state again */
217#define TASK_DEAD 64
218#define TASK_WAKEKILL 128
219#define TASK_WAKING 256
220#define TASK_PARKED 512
221#define TASK_NOLOAD 1024
222#define TASK_STATE_MAX 2048
223
224#define TASK_STATE_TO_CHAR_STR "RSDTtXZxKWPN"
225
226extern char ___assert_task_state[1 - 2*!!(
227 sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
228
229/* Convenience macros for the sake of set_task_state */
230#define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
231#define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED)
232#define TASK_TRACED (TASK_WAKEKILL | __TASK_TRACED)
233
234#define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
235
236/* Convenience macros for the sake of wake_up */
237#define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
238#define TASK_ALL (TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
239
240/* get_task_state() */
241#define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \
242 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
243 __TASK_TRACED | EXIT_ZOMBIE | EXIT_DEAD)
244
245#define task_is_traced(task) ((task->state & __TASK_TRACED) != 0)
246#define task_is_stopped(task) ((task->state & __TASK_STOPPED) != 0)
247#define task_is_stopped_or_traced(task) \
248 ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
249#define task_contributes_to_load(task) \
250 ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
251 (task->flags & PF_FROZEN) == 0 && \
252 (task->state & TASK_NOLOAD) == 0)
253
254#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
255
256#define __set_task_state(tsk, state_value) \
257 do { \
258 (tsk)->task_state_change = _THIS_IP_; \
259 (tsk)->state = (state_value); \
260 } while (0)
261#define set_task_state(tsk, state_value) \
262 do { \
263 (tsk)->task_state_change = _THIS_IP_; \
264 smp_store_mb((tsk)->state, (state_value)); \
265 } while (0)
266
267/*
268 * set_current_state() includes a barrier so that the write of current->state
269 * is correctly serialised wrt the caller's subsequent test of whether to
270 * actually sleep:
271 *
272 * set_current_state(TASK_UNINTERRUPTIBLE);
273 * if (do_i_need_to_sleep())
274 * schedule();
275 *
276 * If the caller does not need such serialisation then use __set_current_state()
277 */
278#define __set_current_state(state_value) \
279 do { \
280 current->task_state_change = _THIS_IP_; \
281 current->state = (state_value); \
282 } while (0)
283#define set_current_state(state_value) \
284 do { \
285 current->task_state_change = _THIS_IP_; \
286 smp_store_mb(current->state, (state_value)); \
287 } while (0)
288
289#else
290
291#define __set_task_state(tsk, state_value) \
292 do { (tsk)->state = (state_value); } while (0)
293#define set_task_state(tsk, state_value) \
294 smp_store_mb((tsk)->state, (state_value))
295
296/*
297 * set_current_state() includes a barrier so that the write of current->state
298 * is correctly serialised wrt the caller's subsequent test of whether to
299 * actually sleep:
300 *
301 * set_current_state(TASK_UNINTERRUPTIBLE);
302 * if (do_i_need_to_sleep())
303 * schedule();
304 *
305 * If the caller does not need such serialisation then use __set_current_state()
306 */
307#define __set_current_state(state_value) \
308 do { current->state = (state_value); } while (0)
309#define set_current_state(state_value) \
310 smp_store_mb(current->state, (state_value))
311
312#endif
313
314/* Task command name length */
315#define TASK_COMM_LEN 16
316
317#include <linux/spinlock.h>
318
319/*
320 * This serializes "schedule()" and also protects
321 * the run-queue from deletions/modifications (but
322 * _adding_ to the beginning of the run-queue has
323 * a separate lock).
324 */
325extern rwlock_t tasklist_lock;
326extern spinlock_t mmlist_lock;
327
328struct task_struct;
329
330#ifdef CONFIG_PROVE_RCU
331extern int lockdep_tasklist_lock_is_held(void);
332#endif /* #ifdef CONFIG_PROVE_RCU */
333
334extern void sched_init(void);
335extern void sched_init_smp(void);
336extern asmlinkage void schedule_tail(struct task_struct *prev);
337extern void init_idle(struct task_struct *idle, int cpu);
338extern void init_idle_bootup_task(struct task_struct *idle);
339
340extern cpumask_var_t cpu_isolated_map;
341
342extern int runqueue_is_locked(int cpu);
343
344#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
345extern void nohz_balance_enter_idle(int cpu);
346extern void set_cpu_sd_state_idle(void);
347extern int get_nohz_timer_target(void);
348#else
349static inline void nohz_balance_enter_idle(int cpu) { }
350static inline void set_cpu_sd_state_idle(void) { }
351#endif
352
353/*
354 * Only dump TASK_* tasks. (0 for all tasks)
355 */
356extern void show_state_filter(unsigned long state_filter);
357
358static inline void show_state(void)
359{
360 show_state_filter(0);
361}
362
363extern void show_regs(struct pt_regs *);
364
365/*
366 * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
367 * task), SP is the stack pointer of the first frame that should be shown in the back
368 * trace (or NULL if the entire call-chain of the task should be shown).
369 */
370extern void show_stack(struct task_struct *task, unsigned long *sp);
371
372extern void cpu_init (void);
373extern void trap_init(void);
374extern void update_process_times(int user);
375extern void scheduler_tick(void);
376
377extern void sched_show_task(struct task_struct *p);
378
379#ifdef CONFIG_LOCKUP_DETECTOR
380extern void touch_softlockup_watchdog(void);
381extern void touch_softlockup_watchdog_sync(void);
382extern void touch_all_softlockup_watchdogs(void);
383extern int proc_dowatchdog_thresh(struct ctl_table *table, int write,
384 void __user *buffer,
385 size_t *lenp, loff_t *ppos);
386extern unsigned int softlockup_panic;
387extern unsigned int hardlockup_panic;
388void lockup_detector_init(void);
389#else
390static inline void touch_softlockup_watchdog(void)
391{
392}
393static inline void touch_softlockup_watchdog_sync(void)
394{
395}
396static inline void touch_all_softlockup_watchdogs(void)
397{
398}
399static inline void lockup_detector_init(void)
400{
401}
402#endif
403
404#ifdef CONFIG_DETECT_HUNG_TASK
405void reset_hung_task_detector(void);
406#else
407static inline void reset_hung_task_detector(void)
408{
409}
410#endif
411
412/* Attach to any functions which should be ignored in wchan output. */
413#define __sched __attribute__((__section__(".sched.text")))
414
415/* Linker adds these: start and end of __sched functions */
416extern char __sched_text_start[], __sched_text_end[];
417
418/* Is this address in the __sched functions? */
419extern int in_sched_functions(unsigned long addr);
420
421#define MAX_SCHEDULE_TIMEOUT LONG_MAX
422extern signed long schedule_timeout(signed long timeout);
423extern signed long schedule_timeout_interruptible(signed long timeout);
424extern signed long schedule_timeout_killable(signed long timeout);
425extern signed long schedule_timeout_uninterruptible(signed long timeout);
426asmlinkage void schedule(void);
427extern void schedule_preempt_disabled(void);
428
429extern long io_schedule_timeout(long timeout);
430
431static inline void io_schedule(void)
432{
433 io_schedule_timeout(MAX_SCHEDULE_TIMEOUT);
434}
435
436struct nsproxy;
437struct user_namespace;
438
439#ifdef CONFIG_MMU
440extern void arch_pick_mmap_layout(struct mm_struct *mm);
441extern unsigned long
442arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
443 unsigned long, unsigned long);
444extern unsigned long
445arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
446 unsigned long len, unsigned long pgoff,
447 unsigned long flags);
448#else
449static inline void arch_pick_mmap_layout(struct mm_struct *mm) {}
450#endif
451
452#define SUID_DUMP_DISABLE 0 /* No setuid dumping */
453#define SUID_DUMP_USER 1 /* Dump as user of process */
454#define SUID_DUMP_ROOT 2 /* Dump as root */
455
456/* mm flags */
457
458/* for SUID_DUMP_* above */
459#define MMF_DUMPABLE_BITS 2
460#define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
461
462extern void set_dumpable(struct mm_struct *mm, int value);
463/*
464 * This returns the actual value of the suid_dumpable flag. For things
465 * that are using this for checking for privilege transitions, it must
466 * test against SUID_DUMP_USER rather than treating it as a boolean
467 * value.
468 */
469static inline int __get_dumpable(unsigned long mm_flags)
470{
471 return mm_flags & MMF_DUMPABLE_MASK;
472}
473
474static inline int get_dumpable(struct mm_struct *mm)
475{
476 return __get_dumpable(mm->flags);
477}
478
479/* coredump filter bits */
480#define MMF_DUMP_ANON_PRIVATE 2
481#define MMF_DUMP_ANON_SHARED 3
482#define MMF_DUMP_MAPPED_PRIVATE 4
483#define MMF_DUMP_MAPPED_SHARED 5
484#define MMF_DUMP_ELF_HEADERS 6
485#define MMF_DUMP_HUGETLB_PRIVATE 7
486#define MMF_DUMP_HUGETLB_SHARED 8
487#define MMF_DUMP_DAX_PRIVATE 9
488#define MMF_DUMP_DAX_SHARED 10
489
490#define MMF_DUMP_FILTER_SHIFT MMF_DUMPABLE_BITS
491#define MMF_DUMP_FILTER_BITS 9
492#define MMF_DUMP_FILTER_MASK \
493 (((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
494#define MMF_DUMP_FILTER_DEFAULT \
495 ((1 << MMF_DUMP_ANON_PRIVATE) | (1 << MMF_DUMP_ANON_SHARED) |\
496 (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
497
498#ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
499# define MMF_DUMP_MASK_DEFAULT_ELF (1 << MMF_DUMP_ELF_HEADERS)
500#else
501# define MMF_DUMP_MASK_DEFAULT_ELF 0
502#endif
503 /* leave room for more dump flags */
504#define MMF_VM_MERGEABLE 16 /* KSM may merge identical pages */
505#define MMF_VM_HUGEPAGE 17 /* set when VM_HUGEPAGE is set on vma */
506#define MMF_EXE_FILE_CHANGED 18 /* see prctl_set_mm_exe_file() */
507
508#define MMF_HAS_UPROBES 19 /* has uprobes */
509#define MMF_RECALC_UPROBES 20 /* MMF_HAS_UPROBES can be wrong */
510
511#define MMF_INIT_MASK (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
512
513struct sighand_struct {
514 atomic_t count;
515 struct k_sigaction action[_NSIG];
516 spinlock_t siglock;
517 wait_queue_head_t signalfd_wqh;
518};
519
520struct pacct_struct {
521 int ac_flag;
522 long ac_exitcode;
523 unsigned long ac_mem;
524 cputime_t ac_utime, ac_stime;
525 unsigned long ac_minflt, ac_majflt;
526};
527
528struct cpu_itimer {
529 cputime_t expires;
530 cputime_t incr;
531 u32 error;
532 u32 incr_error;
533};
534
535/**
536 * struct prev_cputime - snaphsot of system and user cputime
537 * @utime: time spent in user mode
538 * @stime: time spent in system mode
539 * @lock: protects the above two fields
540 *
541 * Stores previous user/system time values such that we can guarantee
542 * monotonicity.
543 */
544struct prev_cputime {
545#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
546 cputime_t utime;
547 cputime_t stime;
548 raw_spinlock_t lock;
549#endif
550};
551
552static inline void prev_cputime_init(struct prev_cputime *prev)
553{
554#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
555 prev->utime = prev->stime = 0;
556 raw_spin_lock_init(&prev->lock);
557#endif
558}
559
560/**
561 * struct task_cputime - collected CPU time counts
562 * @utime: time spent in user mode, in &cputime_t units
563 * @stime: time spent in kernel mode, in &cputime_t units
564 * @sum_exec_runtime: total time spent on the CPU, in nanoseconds
565 *
566 * This structure groups together three kinds of CPU time that are tracked for
567 * threads and thread groups. Most things considering CPU time want to group
568 * these counts together and treat all three of them in parallel.
569 */
570struct task_cputime {
571 cputime_t utime;
572 cputime_t stime;
573 unsigned long long sum_exec_runtime;
574};
575
576/* Alternate field names when used to cache expirations. */
577#define virt_exp utime
578#define prof_exp stime
579#define sched_exp sum_exec_runtime
580
581#define INIT_CPUTIME \
582 (struct task_cputime) { \
583 .utime = 0, \
584 .stime = 0, \
585 .sum_exec_runtime = 0, \
586 }
587
588/*
589 * This is the atomic variant of task_cputime, which can be used for
590 * storing and updating task_cputime statistics without locking.
591 */
592struct task_cputime_atomic {
593 atomic64_t utime;
594 atomic64_t stime;
595 atomic64_t sum_exec_runtime;
596};
597
598#define INIT_CPUTIME_ATOMIC \
599 (struct task_cputime_atomic) { \
600 .utime = ATOMIC64_INIT(0), \
601 .stime = ATOMIC64_INIT(0), \
602 .sum_exec_runtime = ATOMIC64_INIT(0), \
603 }
604
605#define PREEMPT_DISABLED (PREEMPT_DISABLE_OFFSET + PREEMPT_ENABLED)
606
607/*
608 * Disable preemption until the scheduler is running -- use an unconditional
609 * value so that it also works on !PREEMPT_COUNT kernels.
610 *
611 * Reset by start_kernel()->sched_init()->init_idle()->init_idle_preempt_count().
612 */
613#define INIT_PREEMPT_COUNT PREEMPT_OFFSET
614
615/*
616 * Initial preempt_count value; reflects the preempt_count schedule invariant
617 * which states that during context switches:
618 *
619 * preempt_count() == 2*PREEMPT_DISABLE_OFFSET
620 *
621 * Note: PREEMPT_DISABLE_OFFSET is 0 for !PREEMPT_COUNT kernels.
622 * Note: See finish_task_switch().
623 */
624#define FORK_PREEMPT_COUNT (2*PREEMPT_DISABLE_OFFSET + PREEMPT_ENABLED)
625
626/**
627 * struct thread_group_cputimer - thread group interval timer counts
628 * @cputime_atomic: atomic thread group interval timers.
629 * @running: true when there are timers running and
630 * @cputime_atomic receives updates.
631 * @checking_timer: true when a thread in the group is in the
632 * process of checking for thread group timers.
633 *
634 * This structure contains the version of task_cputime, above, that is
635 * used for thread group CPU timer calculations.
636 */
637struct thread_group_cputimer {
638 struct task_cputime_atomic cputime_atomic;
639 bool running;
640 bool checking_timer;
641};
642
643#include <linux/rwsem.h>
644struct autogroup;
645
646/*
647 * NOTE! "signal_struct" does not have its own
648 * locking, because a shared signal_struct always
649 * implies a shared sighand_struct, so locking
650 * sighand_struct is always a proper superset of
651 * the locking of signal_struct.
652 */
653struct signal_struct {
654 atomic_t sigcnt;
655 atomic_t live;
656 int nr_threads;
657 struct list_head thread_head;
658
659 wait_queue_head_t wait_chldexit; /* for wait4() */
660
661 /* current thread group signal load-balancing target: */
662 struct task_struct *curr_target;
663
664 /* shared signal handling: */
665 struct sigpending shared_pending;
666
667 /* thread group exit support */
668 int group_exit_code;
669 /* overloaded:
670 * - notify group_exit_task when ->count is equal to notify_count
671 * - everyone except group_exit_task is stopped during signal delivery
672 * of fatal signals, group_exit_task processes the signal.
673 */
674 int notify_count;
675 struct task_struct *group_exit_task;
676
677 /* thread group stop support, overloads group_exit_code too */
678 int group_stop_count;
679 unsigned int flags; /* see SIGNAL_* flags below */
680
681 /*
682 * PR_SET_CHILD_SUBREAPER marks a process, like a service
683 * manager, to re-parent orphan (double-forking) child processes
684 * to this process instead of 'init'. The service manager is
685 * able to receive SIGCHLD signals and is able to investigate
686 * the process until it calls wait(). All children of this
687 * process will inherit a flag if they should look for a
688 * child_subreaper process at exit.
689 */
690 unsigned int is_child_subreaper:1;
691 unsigned int has_child_subreaper:1;
692
693 /* POSIX.1b Interval Timers */
694 int posix_timer_id;
695 struct list_head posix_timers;
696
697 /* ITIMER_REAL timer for the process */
698 struct hrtimer real_timer;
699 struct pid *leader_pid;
700 ktime_t it_real_incr;
701
702 /*
703 * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
704 * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
705 * values are defined to 0 and 1 respectively
706 */
707 struct cpu_itimer it[2];
708
709 /*
710 * Thread group totals for process CPU timers.
711 * See thread_group_cputimer(), et al, for details.
712 */
713 struct thread_group_cputimer cputimer;
714
715 /* Earliest-expiration cache. */
716 struct task_cputime cputime_expires;
717
718 struct list_head cpu_timers[3];
719
720 struct pid *tty_old_pgrp;
721
722 /* boolean value for session group leader */
723 int leader;
724
725 struct tty_struct *tty; /* NULL if no tty */
726
727#ifdef CONFIG_SCHED_AUTOGROUP
728 struct autogroup *autogroup;
729#endif
730 /*
731 * Cumulative resource counters for dead threads in the group,
732 * and for reaped dead child processes forked by this group.
733 * Live threads maintain their own counters and add to these
734 * in __exit_signal, except for the group leader.
735 */
736 seqlock_t stats_lock;
737 cputime_t utime, stime, cutime, cstime;
738 cputime_t gtime;
739 cputime_t cgtime;
740 struct prev_cputime prev_cputime;
741 unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
742 unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
743 unsigned long inblock, oublock, cinblock, coublock;
744 unsigned long maxrss, cmaxrss;
745 struct task_io_accounting ioac;
746
747 /*
748 * Cumulative ns of schedule CPU time fo dead threads in the
749 * group, not including a zombie group leader, (This only differs
750 * from jiffies_to_ns(utime + stime) if sched_clock uses something
751 * other than jiffies.)
752 */
753 unsigned long long sum_sched_runtime;
754
755 /*
756 * We don't bother to synchronize most readers of this at all,
757 * because there is no reader checking a limit that actually needs
758 * to get both rlim_cur and rlim_max atomically, and either one
759 * alone is a single word that can safely be read normally.
760 * getrlimit/setrlimit use task_lock(current->group_leader) to
761 * protect this instead of the siglock, because they really
762 * have no need to disable irqs.
763 */
764 struct rlimit rlim[RLIM_NLIMITS];
765
766#ifdef CONFIG_BSD_PROCESS_ACCT
767 struct pacct_struct pacct; /* per-process accounting information */
768#endif
769#ifdef CONFIG_TASKSTATS
770 struct taskstats *stats;
771#endif
772#ifdef CONFIG_AUDIT
773 unsigned audit_tty;
774 unsigned audit_tty_log_passwd;
775 struct tty_audit_buf *tty_audit_buf;
776#endif
777
778 oom_flags_t oom_flags;
779 short oom_score_adj; /* OOM kill score adjustment */
780 short oom_score_adj_min; /* OOM kill score adjustment min value.
781 * Only settable by CAP_SYS_RESOURCE. */
782
783 struct mutex cred_guard_mutex; /* guard against foreign influences on
784 * credential calculations
785 * (notably. ptrace) */
786};
787
788/*
789 * Bits in flags field of signal_struct.
790 */
791#define SIGNAL_STOP_STOPPED 0x00000001 /* job control stop in effect */
792#define SIGNAL_STOP_CONTINUED 0x00000002 /* SIGCONT since WCONTINUED reap */
793#define SIGNAL_GROUP_EXIT 0x00000004 /* group exit in progress */
794#define SIGNAL_GROUP_COREDUMP 0x00000008 /* coredump in progress */
795/*
796 * Pending notifications to parent.
797 */
798#define SIGNAL_CLD_STOPPED 0x00000010
799#define SIGNAL_CLD_CONTINUED 0x00000020
800#define SIGNAL_CLD_MASK (SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
801
802#define SIGNAL_UNKILLABLE 0x00000040 /* for init: ignore fatal signals */
803
804/* If true, all threads except ->group_exit_task have pending SIGKILL */
805static inline int signal_group_exit(const struct signal_struct *sig)
806{
807 return (sig->flags & SIGNAL_GROUP_EXIT) ||
808 (sig->group_exit_task != NULL);
809}
810
811/*
812 * Some day this will be a full-fledged user tracking system..
813 */
814struct user_struct {
815 atomic_t __count; /* reference count */
816 atomic_t processes; /* How many processes does this user have? */
817 atomic_t sigpending; /* How many pending signals does this user have? */
818#ifdef CONFIG_INOTIFY_USER
819 atomic_t inotify_watches; /* How many inotify watches does this user have? */
820 atomic_t inotify_devs; /* How many inotify devs does this user have opened? */
821#endif
822#ifdef CONFIG_FANOTIFY
823 atomic_t fanotify_listeners;
824#endif
825#ifdef CONFIG_EPOLL
826 atomic_long_t epoll_watches; /* The number of file descriptors currently watched */
827#endif
828#ifdef CONFIG_POSIX_MQUEUE
829 /* protected by mq_lock */
830 unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */
831#endif
832 unsigned long locked_shm; /* How many pages of mlocked shm ? */
833
834#ifdef CONFIG_KEYS
835 struct key *uid_keyring; /* UID specific keyring */
836 struct key *session_keyring; /* UID's default session keyring */
837#endif
838
839 /* Hash table maintenance information */
840 struct hlist_node uidhash_node;
841 kuid_t uid;
842
843#if defined(CONFIG_PERF_EVENTS) || defined(CONFIG_BPF_SYSCALL)
844 atomic_long_t locked_vm;
845#endif
846};
847
848extern int uids_sysfs_init(void);
849
850extern struct user_struct *find_user(kuid_t);
851
852extern struct user_struct root_user;
853#define INIT_USER (&root_user)
854
855
856struct backing_dev_info;
857struct reclaim_state;
858
859#ifdef CONFIG_SCHED_INFO
860struct sched_info {
861 /* cumulative counters */
862 unsigned long pcount; /* # of times run on this cpu */
863 unsigned long long run_delay; /* time spent waiting on a runqueue */
864
865 /* timestamps */
866 unsigned long long last_arrival,/* when we last ran on a cpu */
867 last_queued; /* when we were last queued to run */
868};
869#endif /* CONFIG_SCHED_INFO */
870
871#ifdef CONFIG_TASK_DELAY_ACCT
872struct task_delay_info {
873 spinlock_t lock;
874 unsigned int flags; /* Private per-task flags */
875
876 /* For each stat XXX, add following, aligned appropriately
877 *
878 * struct timespec XXX_start, XXX_end;
879 * u64 XXX_delay;
880 * u32 XXX_count;
881 *
882 * Atomicity of updates to XXX_delay, XXX_count protected by
883 * single lock above (split into XXX_lock if contention is an issue).
884 */
885
886 /*
887 * XXX_count is incremented on every XXX operation, the delay
888 * associated with the operation is added to XXX_delay.
889 * XXX_delay contains the accumulated delay time in nanoseconds.
890 */
891 u64 blkio_start; /* Shared by blkio, swapin */
892 u64 blkio_delay; /* wait for sync block io completion */
893 u64 swapin_delay; /* wait for swapin block io completion */
894 u32 blkio_count; /* total count of the number of sync block */
895 /* io operations performed */
896 u32 swapin_count; /* total count of the number of swapin block */
897 /* io operations performed */
898
899 u64 freepages_start;
900 u64 freepages_delay; /* wait for memory reclaim */
901 u32 freepages_count; /* total count of memory reclaim */
902};
903#endif /* CONFIG_TASK_DELAY_ACCT */
904
905static inline int sched_info_on(void)
906{
907#ifdef CONFIG_SCHEDSTATS
908 return 1;
909#elif defined(CONFIG_TASK_DELAY_ACCT)
910 extern int delayacct_on;
911 return delayacct_on;
912#else
913 return 0;
914#endif
915}
916
917enum cpu_idle_type {
918 CPU_IDLE,
919 CPU_NOT_IDLE,
920 CPU_NEWLY_IDLE,
921 CPU_MAX_IDLE_TYPES
922};
923
924/*
925 * Increase resolution of cpu_capacity calculations
926 */
927#define SCHED_CAPACITY_SHIFT 10
928#define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT)
929
930/*
931 * Wake-queues are lists of tasks with a pending wakeup, whose
932 * callers have already marked the task as woken internally,
933 * and can thus carry on. A common use case is being able to
934 * do the wakeups once the corresponding user lock as been
935 * released.
936 *
937 * We hold reference to each task in the list across the wakeup,
938 * thus guaranteeing that the memory is still valid by the time
939 * the actual wakeups are performed in wake_up_q().
940 *
941 * One per task suffices, because there's never a need for a task to be
942 * in two wake queues simultaneously; it is forbidden to abandon a task
943 * in a wake queue (a call to wake_up_q() _must_ follow), so if a task is
944 * already in a wake queue, the wakeup will happen soon and the second
945 * waker can just skip it.
946 *
947 * The WAKE_Q macro declares and initializes the list head.
948 * wake_up_q() does NOT reinitialize the list; it's expected to be
949 * called near the end of a function, where the fact that the queue is
950 * not used again will be easy to see by inspection.
951 *
952 * Note that this can cause spurious wakeups. schedule() callers
953 * must ensure the call is done inside a loop, confirming that the
954 * wakeup condition has in fact occurred.
955 */
956struct wake_q_node {
957 struct wake_q_node *next;
958};
959
960struct wake_q_head {
961 struct wake_q_node *first;
962 struct wake_q_node **lastp;
963};
964
965#define WAKE_Q_TAIL ((struct wake_q_node *) 0x01)
966
967#define WAKE_Q(name) \
968 struct wake_q_head name = { WAKE_Q_TAIL, &name.first }
969
970extern void wake_q_add(struct wake_q_head *head,
971 struct task_struct *task);
972extern void wake_up_q(struct wake_q_head *head);
973
974/*
975 * sched-domains (multiprocessor balancing) declarations:
976 */
977#ifdef CONFIG_SMP
978#define SD_LOAD_BALANCE 0x0001 /* Do load balancing on this domain. */
979#define SD_BALANCE_NEWIDLE 0x0002 /* Balance when about to become idle */
980#define SD_BALANCE_EXEC 0x0004 /* Balance on exec */
981#define SD_BALANCE_FORK 0x0008 /* Balance on fork, clone */
982#define SD_BALANCE_WAKE 0x0010 /* Balance on wakeup */
983#define SD_WAKE_AFFINE 0x0020 /* Wake task to waking CPU */
984#define SD_SHARE_CPUCAPACITY 0x0080 /* Domain members share cpu power */
985#define SD_SHARE_POWERDOMAIN 0x0100 /* Domain members share power domain */
986#define SD_SHARE_PKG_RESOURCES 0x0200 /* Domain members share cpu pkg resources */
987#define SD_SERIALIZE 0x0400 /* Only a single load balancing instance */
988#define SD_ASYM_PACKING 0x0800 /* Place busy groups earlier in the domain */
989#define SD_PREFER_SIBLING 0x1000 /* Prefer to place tasks in a sibling domain */
990#define SD_OVERLAP 0x2000 /* sched_domains of this level overlap */
991#define SD_NUMA 0x4000 /* cross-node balancing */
992
993#ifdef CONFIG_SCHED_SMT
994static inline int cpu_smt_flags(void)
995{
996 return SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
997}
998#endif
999
1000#ifdef CONFIG_SCHED_MC
1001static inline int cpu_core_flags(void)
1002{
1003 return SD_SHARE_PKG_RESOURCES;
1004}
1005#endif
1006
1007#ifdef CONFIG_NUMA
1008static inline int cpu_numa_flags(void)
1009{
1010 return SD_NUMA;
1011}
1012#endif
1013
1014struct sched_domain_attr {
1015 int relax_domain_level;
1016};
1017
1018#define SD_ATTR_INIT (struct sched_domain_attr) { \
1019 .relax_domain_level = -1, \
1020}
1021
1022extern int sched_domain_level_max;
1023
1024struct sched_group;
1025
1026struct sched_domain {
1027 /* These fields must be setup */
1028 struct sched_domain *parent; /* top domain must be null terminated */
1029 struct sched_domain *child; /* bottom domain must be null terminated */
1030 struct sched_group *groups; /* the balancing groups of the domain */
1031 unsigned long min_interval; /* Minimum balance interval ms */
1032 unsigned long max_interval; /* Maximum balance interval ms */
1033 unsigned int busy_factor; /* less balancing by factor if busy */
1034 unsigned int imbalance_pct; /* No balance until over watermark */
1035 unsigned int cache_nice_tries; /* Leave cache hot tasks for # tries */
1036 unsigned int busy_idx;
1037 unsigned int idle_idx;
1038 unsigned int newidle_idx;
1039 unsigned int wake_idx;
1040 unsigned int forkexec_idx;
1041 unsigned int smt_gain;
1042
1043 int nohz_idle; /* NOHZ IDLE status */
1044 int flags; /* See SD_* */
1045 int level;
1046
1047 /* Runtime fields. */
1048 unsigned long last_balance; /* init to jiffies. units in jiffies */
1049 unsigned int balance_interval; /* initialise to 1. units in ms. */
1050 unsigned int nr_balance_failed; /* initialise to 0 */
1051
1052 /* idle_balance() stats */
1053 u64 max_newidle_lb_cost;
1054 unsigned long next_decay_max_lb_cost;
1055
1056#ifdef CONFIG_SCHEDSTATS
1057 /* load_balance() stats */
1058 unsigned int lb_count[CPU_MAX_IDLE_TYPES];
1059 unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
1060 unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
1061 unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
1062 unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
1063 unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
1064 unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
1065 unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
1066
1067 /* Active load balancing */
1068 unsigned int alb_count;
1069 unsigned int alb_failed;
1070 unsigned int alb_pushed;
1071
1072 /* SD_BALANCE_EXEC stats */
1073 unsigned int sbe_count;
1074 unsigned int sbe_balanced;
1075 unsigned int sbe_pushed;
1076
1077 /* SD_BALANCE_FORK stats */
1078 unsigned int sbf_count;
1079 unsigned int sbf_balanced;
1080 unsigned int sbf_pushed;
1081
1082 /* try_to_wake_up() stats */
1083 unsigned int ttwu_wake_remote;
1084 unsigned int ttwu_move_affine;
1085 unsigned int ttwu_move_balance;
1086#endif
1087#ifdef CONFIG_SCHED_DEBUG
1088 char *name;
1089#endif
1090 union {
1091 void *private; /* used during construction */
1092 struct rcu_head rcu; /* used during destruction */
1093 };
1094
1095 unsigned int span_weight;
1096 /*
1097 * Span of all CPUs in this domain.
1098 *
1099 * NOTE: this field is variable length. (Allocated dynamically
1100 * by attaching extra space to the end of the structure,
1101 * depending on how many CPUs the kernel has booted up with)
1102 */
1103 unsigned long span[0];
1104};
1105
1106static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
1107{
1108 return to_cpumask(sd->span);
1109}
1110
1111extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1112 struct sched_domain_attr *dattr_new);
1113
1114/* Allocate an array of sched domains, for partition_sched_domains(). */
1115cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
1116void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
1117
1118bool cpus_share_cache(int this_cpu, int that_cpu);
1119
1120typedef const struct cpumask *(*sched_domain_mask_f)(int cpu);
1121typedef int (*sched_domain_flags_f)(void);
1122
1123#define SDTL_OVERLAP 0x01
1124
1125struct sd_data {
1126 struct sched_domain **__percpu sd;
1127 struct sched_group **__percpu sg;
1128 struct sched_group_capacity **__percpu sgc;
1129};
1130
1131struct sched_domain_topology_level {
1132 sched_domain_mask_f mask;
1133 sched_domain_flags_f sd_flags;
1134 int flags;
1135 int numa_level;
1136 struct sd_data data;
1137#ifdef CONFIG_SCHED_DEBUG
1138 char *name;
1139#endif
1140};
1141
1142extern void set_sched_topology(struct sched_domain_topology_level *tl);
1143extern void wake_up_if_idle(int cpu);
1144
1145#ifdef CONFIG_SCHED_DEBUG
1146# define SD_INIT_NAME(type) .name = #type
1147#else
1148# define SD_INIT_NAME(type)
1149#endif
1150
1151#else /* CONFIG_SMP */
1152
1153struct sched_domain_attr;
1154
1155static inline void
1156partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1157 struct sched_domain_attr *dattr_new)
1158{
1159}
1160
1161static inline bool cpus_share_cache(int this_cpu, int that_cpu)
1162{
1163 return true;
1164}
1165
1166#endif /* !CONFIG_SMP */
1167
1168
1169struct io_context; /* See blkdev.h */
1170
1171
1172#ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
1173extern void prefetch_stack(struct task_struct *t);
1174#else
1175static inline void prefetch_stack(struct task_struct *t) { }
1176#endif
1177
1178struct audit_context; /* See audit.c */
1179struct mempolicy;
1180struct pipe_inode_info;
1181struct uts_namespace;
1182
1183struct load_weight {
1184 unsigned long weight;
1185 u32 inv_weight;
1186};
1187
1188/*
1189 * The load_avg/util_avg accumulates an infinite geometric series.
1190 * 1) load_avg factors frequency scaling into the amount of time that a
1191 * sched_entity is runnable on a rq into its weight. For cfs_rq, it is the
1192 * aggregated such weights of all runnable and blocked sched_entities.
1193 * 2) util_avg factors frequency and cpu scaling into the amount of time
1194 * that a sched_entity is running on a CPU, in the range [0..SCHED_LOAD_SCALE].
1195 * For cfs_rq, it is the aggregated such times of all runnable and
1196 * blocked sched_entities.
1197 * The 64 bit load_sum can:
1198 * 1) for cfs_rq, afford 4353082796 (=2^64/47742/88761) entities with
1199 * the highest weight (=88761) always runnable, we should not overflow
1200 * 2) for entity, support any load.weight always runnable
1201 */
1202struct sched_avg {
1203 u64 last_update_time, load_sum;
1204 u32 util_sum, period_contrib;
1205 unsigned long load_avg, util_avg;
1206};
1207
1208#ifdef CONFIG_SCHEDSTATS
1209struct sched_statistics {
1210 u64 wait_start;
1211 u64 wait_max;
1212 u64 wait_count;
1213 u64 wait_sum;
1214 u64 iowait_count;
1215 u64 iowait_sum;
1216
1217 u64 sleep_start;
1218 u64 sleep_max;
1219 s64 sum_sleep_runtime;
1220
1221 u64 block_start;
1222 u64 block_max;
1223 u64 exec_max;
1224 u64 slice_max;
1225
1226 u64 nr_migrations_cold;
1227 u64 nr_failed_migrations_affine;
1228 u64 nr_failed_migrations_running;
1229 u64 nr_failed_migrations_hot;
1230 u64 nr_forced_migrations;
1231
1232 u64 nr_wakeups;
1233 u64 nr_wakeups_sync;
1234 u64 nr_wakeups_migrate;
1235 u64 nr_wakeups_local;
1236 u64 nr_wakeups_remote;
1237 u64 nr_wakeups_affine;
1238 u64 nr_wakeups_affine_attempts;
1239 u64 nr_wakeups_passive;
1240 u64 nr_wakeups_idle;
1241};
1242#endif
1243
1244struct sched_entity {
1245 struct load_weight load; /* for load-balancing */
1246 struct rb_node run_node;
1247 struct list_head group_node;
1248 unsigned int on_rq;
1249
1250 u64 exec_start;
1251 u64 sum_exec_runtime;
1252 u64 vruntime;
1253 u64 prev_sum_exec_runtime;
1254
1255 u64 nr_migrations;
1256
1257#ifdef CONFIG_SCHEDSTATS
1258 struct sched_statistics statistics;
1259#endif
1260
1261#ifdef CONFIG_FAIR_GROUP_SCHED
1262 int depth;
1263 struct sched_entity *parent;
1264 /* rq on which this entity is (to be) queued: */
1265 struct cfs_rq *cfs_rq;
1266 /* rq "owned" by this entity/group: */
1267 struct cfs_rq *my_q;
1268#endif
1269
1270#ifdef CONFIG_SMP
1271 /* Per entity load average tracking */
1272 struct sched_avg avg;
1273#endif
1274};
1275
1276struct sched_rt_entity {
1277 struct list_head run_list;
1278 unsigned long timeout;
1279 unsigned long watchdog_stamp;
1280 unsigned int time_slice;
1281
1282 struct sched_rt_entity *back;
1283#ifdef CONFIG_RT_GROUP_SCHED
1284 struct sched_rt_entity *parent;
1285 /* rq on which this entity is (to be) queued: */
1286 struct rt_rq *rt_rq;
1287 /* rq "owned" by this entity/group: */
1288 struct rt_rq *my_q;
1289#endif
1290};
1291
1292struct sched_dl_entity {
1293 struct rb_node rb_node;
1294
1295 /*
1296 * Original scheduling parameters. Copied here from sched_attr
1297 * during sched_setattr(), they will remain the same until
1298 * the next sched_setattr().
1299 */
1300 u64 dl_runtime; /* maximum runtime for each instance */
1301 u64 dl_deadline; /* relative deadline of each instance */
1302 u64 dl_period; /* separation of two instances (period) */
1303 u64 dl_bw; /* dl_runtime / dl_deadline */
1304
1305 /*
1306 * Actual scheduling parameters. Initialized with the values above,
1307 * they are continously updated during task execution. Note that
1308 * the remaining runtime could be < 0 in case we are in overrun.
1309 */
1310 s64 runtime; /* remaining runtime for this instance */
1311 u64 deadline; /* absolute deadline for this instance */
1312 unsigned int flags; /* specifying the scheduler behaviour */
1313
1314 /*
1315 * Some bool flags:
1316 *
1317 * @dl_throttled tells if we exhausted the runtime. If so, the
1318 * task has to wait for a replenishment to be performed at the
1319 * next firing of dl_timer.
1320 *
1321 * @dl_new tells if a new instance arrived. If so we must
1322 * start executing it with full runtime and reset its absolute
1323 * deadline;
1324 *
1325 * @dl_boosted tells if we are boosted due to DI. If so we are
1326 * outside bandwidth enforcement mechanism (but only until we
1327 * exit the critical section);
1328 *
1329 * @dl_yielded tells if task gave up the cpu before consuming
1330 * all its available runtime during the last job.
1331 */
1332 int dl_throttled, dl_new, dl_boosted, dl_yielded;
1333
1334 /*
1335 * Bandwidth enforcement timer. Each -deadline task has its
1336 * own bandwidth to be enforced, thus we need one timer per task.
1337 */
1338 struct hrtimer dl_timer;
1339};
1340
1341union rcu_special {
1342 struct {
1343 u8 blocked;
1344 u8 need_qs;
1345 u8 exp_need_qs;
1346 u8 pad; /* Otherwise the compiler can store garbage here. */
1347 } b; /* Bits. */
1348 u32 s; /* Set of bits. */
1349};
1350struct rcu_node;
1351
1352enum perf_event_task_context {
1353 perf_invalid_context = -1,
1354 perf_hw_context = 0,
1355 perf_sw_context,
1356 perf_nr_task_contexts,
1357};
1358
1359/* Track pages that require TLB flushes */
1360struct tlbflush_unmap_batch {
1361 /*
1362 * Each bit set is a CPU that potentially has a TLB entry for one of
1363 * the PFNs being flushed. See set_tlb_ubc_flush_pending().
1364 */
1365 struct cpumask cpumask;
1366
1367 /* True if any bit in cpumask is set */
1368 bool flush_required;
1369
1370 /*
1371 * If true then the PTE was dirty when unmapped. The entry must be
1372 * flushed before IO is initiated or a stale TLB entry potentially
1373 * allows an update without redirtying the page.
1374 */
1375 bool writable;
1376};
1377
1378struct task_struct {
1379 volatile long state; /* -1 unrunnable, 0 runnable, >0 stopped */
1380 void *stack;
1381 atomic_t usage;
1382 unsigned int flags; /* per process flags, defined below */
1383 unsigned int ptrace;
1384
1385#ifdef CONFIG_SMP
1386 struct llist_node wake_entry;
1387 int on_cpu;
1388 unsigned int wakee_flips;
1389 unsigned long wakee_flip_decay_ts;
1390 struct task_struct *last_wakee;
1391
1392 int wake_cpu;
1393#endif
1394 int on_rq;
1395
1396 int prio, static_prio, normal_prio;
1397 unsigned int rt_priority;
1398 const struct sched_class *sched_class;
1399 struct sched_entity se;
1400 struct sched_rt_entity rt;
1401#ifdef CONFIG_CGROUP_SCHED
1402 struct task_group *sched_task_group;
1403#endif
1404 struct sched_dl_entity dl;
1405
1406#ifdef CONFIG_PREEMPT_NOTIFIERS
1407 /* list of struct preempt_notifier: */
1408 struct hlist_head preempt_notifiers;
1409#endif
1410
1411#ifdef CONFIG_BLK_DEV_IO_TRACE
1412 unsigned int btrace_seq;
1413#endif
1414
1415 unsigned int policy;
1416 int nr_cpus_allowed;
1417 cpumask_t cpus_allowed;
1418
1419#ifdef CONFIG_PREEMPT_RCU
1420 int rcu_read_lock_nesting;
1421 union rcu_special rcu_read_unlock_special;
1422 struct list_head rcu_node_entry;
1423 struct rcu_node *rcu_blocked_node;
1424#endif /* #ifdef CONFIG_PREEMPT_RCU */
1425#ifdef CONFIG_TASKS_RCU
1426 unsigned long rcu_tasks_nvcsw;
1427 bool rcu_tasks_holdout;
1428 struct list_head rcu_tasks_holdout_list;
1429 int rcu_tasks_idle_cpu;
1430#endif /* #ifdef CONFIG_TASKS_RCU */
1431
1432#ifdef CONFIG_SCHED_INFO
1433 struct sched_info sched_info;
1434#endif
1435
1436 struct list_head tasks;
1437#ifdef CONFIG_SMP
1438 struct plist_node pushable_tasks;
1439 struct rb_node pushable_dl_tasks;
1440#endif
1441
1442 struct mm_struct *mm, *active_mm;
1443 /* per-thread vma caching */
1444 u32 vmacache_seqnum;
1445 struct vm_area_struct *vmacache[VMACACHE_SIZE];
1446#if defined(SPLIT_RSS_COUNTING)
1447 struct task_rss_stat rss_stat;
1448#endif
1449/* task state */
1450 int exit_state;
1451 int exit_code, exit_signal;
1452 int pdeath_signal; /* The signal sent when the parent dies */
1453 unsigned long jobctl; /* JOBCTL_*, siglock protected */
1454
1455 /* Used for emulating ABI behavior of previous Linux versions */
1456 unsigned int personality;
1457
1458 unsigned in_execve:1; /* Tell the LSMs that the process is doing an
1459 * execve */
1460 unsigned in_iowait:1;
1461
1462 /* Revert to default priority/policy when forking */
1463 unsigned sched_reset_on_fork:1;
1464 unsigned sched_contributes_to_load:1;
1465 unsigned sched_migrated:1;
1466#ifdef CONFIG_MEMCG
1467 unsigned memcg_may_oom:1;
1468#endif
1469#ifdef CONFIG_MEMCG_KMEM
1470 unsigned memcg_kmem_skip_account:1;
1471#endif
1472#ifdef CONFIG_COMPAT_BRK
1473 unsigned brk_randomized:1;
1474#endif
1475
1476 unsigned long atomic_flags; /* Flags needing atomic access. */
1477
1478 struct restart_block restart_block;
1479
1480 pid_t pid;
1481 pid_t tgid;
1482
1483#ifdef CONFIG_CC_STACKPROTECTOR
1484 /* Canary value for the -fstack-protector gcc feature */
1485 unsigned long stack_canary;
1486#endif
1487 /*
1488 * pointers to (original) parent process, youngest child, younger sibling,
1489 * older sibling, respectively. (p->father can be replaced with
1490 * p->real_parent->pid)
1491 */
1492 struct task_struct __rcu *real_parent; /* real parent process */
1493 struct task_struct __rcu *parent; /* recipient of SIGCHLD, wait4() reports */
1494 /*
1495 * children/sibling forms the list of my natural children
1496 */
1497 struct list_head children; /* list of my children */
1498 struct list_head sibling; /* linkage in my parent's children list */
1499 struct task_struct *group_leader; /* threadgroup leader */
1500
1501 /*
1502 * ptraced is the list of tasks this task is using ptrace on.
1503 * This includes both natural children and PTRACE_ATTACH targets.
1504 * p->ptrace_entry is p's link on the p->parent->ptraced list.
1505 */
1506 struct list_head ptraced;
1507 struct list_head ptrace_entry;
1508
1509 /* PID/PID hash table linkage. */
1510 struct pid_link pids[PIDTYPE_MAX];
1511 struct list_head thread_group;
1512 struct list_head thread_node;
1513
1514 struct completion *vfork_done; /* for vfork() */
1515 int __user *set_child_tid; /* CLONE_CHILD_SETTID */
1516 int __user *clear_child_tid; /* CLONE_CHILD_CLEARTID */
1517
1518 cputime_t utime, stime, utimescaled, stimescaled;
1519 cputime_t gtime;
1520 struct prev_cputime prev_cputime;
1521#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1522 seqlock_t vtime_seqlock;
1523 unsigned long long vtime_snap;
1524 enum {
1525 VTIME_SLEEPING = 0,
1526 VTIME_USER,
1527 VTIME_SYS,
1528 } vtime_snap_whence;
1529#endif
1530 unsigned long nvcsw, nivcsw; /* context switch counts */
1531 u64 start_time; /* monotonic time in nsec */
1532 u64 real_start_time; /* boot based time in nsec */
1533/* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1534 unsigned long min_flt, maj_flt;
1535
1536 struct task_cputime cputime_expires;
1537 struct list_head cpu_timers[3];
1538
1539/* process credentials */
1540 const struct cred __rcu *real_cred; /* objective and real subjective task
1541 * credentials (COW) */
1542 const struct cred __rcu *cred; /* effective (overridable) subjective task
1543 * credentials (COW) */
1544 char comm[TASK_COMM_LEN]; /* executable name excluding path
1545 - access with [gs]et_task_comm (which lock
1546 it with task_lock())
1547 - initialized normally by setup_new_exec */
1548/* file system info */
1549 struct nameidata *nameidata;
1550#ifdef CONFIG_SYSVIPC
1551/* ipc stuff */
1552 struct sysv_sem sysvsem;
1553 struct sysv_shm sysvshm;
1554#endif
1555#ifdef CONFIG_DETECT_HUNG_TASK
1556/* hung task detection */
1557 unsigned long last_switch_count;
1558#endif
1559/* filesystem information */
1560 struct fs_struct *fs;
1561/* open file information */
1562 struct files_struct *files;
1563/* namespaces */
1564 struct nsproxy *nsproxy;
1565/* signal handlers */
1566 struct signal_struct *signal;
1567 struct sighand_struct *sighand;
1568
1569 sigset_t blocked, real_blocked;
1570 sigset_t saved_sigmask; /* restored if set_restore_sigmask() was used */
1571 struct sigpending pending;
1572
1573 unsigned long sas_ss_sp;
1574 size_t sas_ss_size;
1575
1576 struct callback_head *task_works;
1577
1578 struct audit_context *audit_context;
1579#ifdef CONFIG_AUDITSYSCALL
1580 kuid_t loginuid;
1581 unsigned int sessionid;
1582#endif
1583 struct seccomp seccomp;
1584
1585/* Thread group tracking */
1586 u32 parent_exec_id;
1587 u32 self_exec_id;
1588/* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1589 * mempolicy */
1590 spinlock_t alloc_lock;
1591
1592 /* Protection of the PI data structures: */
1593 raw_spinlock_t pi_lock;
1594
1595 struct wake_q_node wake_q;
1596
1597#ifdef CONFIG_RT_MUTEXES
1598 /* PI waiters blocked on a rt_mutex held by this task */
1599 struct rb_root pi_waiters;
1600 struct rb_node *pi_waiters_leftmost;
1601 /* Deadlock detection and priority inheritance handling */
1602 struct rt_mutex_waiter *pi_blocked_on;
1603#endif
1604
1605#ifdef CONFIG_DEBUG_MUTEXES
1606 /* mutex deadlock detection */
1607 struct mutex_waiter *blocked_on;
1608#endif
1609#ifdef CONFIG_TRACE_IRQFLAGS
1610 unsigned int irq_events;
1611 unsigned long hardirq_enable_ip;
1612 unsigned long hardirq_disable_ip;
1613 unsigned int hardirq_enable_event;
1614 unsigned int hardirq_disable_event;
1615 int hardirqs_enabled;
1616 int hardirq_context;
1617 unsigned long softirq_disable_ip;
1618 unsigned long softirq_enable_ip;
1619 unsigned int softirq_disable_event;
1620 unsigned int softirq_enable_event;
1621 int softirqs_enabled;
1622 int softirq_context;
1623#endif
1624#ifdef CONFIG_LOCKDEP
1625# define MAX_LOCK_DEPTH 48UL
1626 u64 curr_chain_key;
1627 int lockdep_depth;
1628 unsigned int lockdep_recursion;
1629 struct held_lock held_locks[MAX_LOCK_DEPTH];
1630 gfp_t lockdep_reclaim_gfp;
1631#endif
1632
1633/* journalling filesystem info */
1634 void *journal_info;
1635
1636/* stacked block device info */
1637 struct bio_list *bio_list;
1638
1639#ifdef CONFIG_BLOCK
1640/* stack plugging */
1641 struct blk_plug *plug;
1642#endif
1643
1644/* VM state */
1645 struct reclaim_state *reclaim_state;
1646
1647 struct backing_dev_info *backing_dev_info;
1648
1649 struct io_context *io_context;
1650
1651 unsigned long ptrace_message;
1652 siginfo_t *last_siginfo; /* For ptrace use. */
1653 struct task_io_accounting ioac;
1654#if defined(CONFIG_TASK_XACCT)
1655 u64 acct_rss_mem1; /* accumulated rss usage */
1656 u64 acct_vm_mem1; /* accumulated virtual memory usage */
1657 cputime_t acct_timexpd; /* stime + utime since last update */
1658#endif
1659#ifdef CONFIG_CPUSETS
1660 nodemask_t mems_allowed; /* Protected by alloc_lock */
1661 seqcount_t mems_allowed_seq; /* Seqence no to catch updates */
1662 int cpuset_mem_spread_rotor;
1663 int cpuset_slab_spread_rotor;
1664#endif
1665#ifdef CONFIG_CGROUPS
1666 /* Control Group info protected by css_set_lock */
1667 struct css_set __rcu *cgroups;
1668 /* cg_list protected by css_set_lock and tsk->alloc_lock */
1669 struct list_head cg_list;
1670#endif
1671#ifdef CONFIG_FUTEX
1672 struct robust_list_head __user *robust_list;
1673#ifdef CONFIG_COMPAT
1674 struct compat_robust_list_head __user *compat_robust_list;
1675#endif
1676 struct list_head pi_state_list;
1677 struct futex_pi_state *pi_state_cache;
1678#endif
1679#ifdef CONFIG_PERF_EVENTS
1680 struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1681 struct mutex perf_event_mutex;
1682 struct list_head perf_event_list;
1683#endif
1684#ifdef CONFIG_DEBUG_PREEMPT
1685 unsigned long preempt_disable_ip;
1686#endif
1687#ifdef CONFIG_NUMA
1688 struct mempolicy *mempolicy; /* Protected by alloc_lock */
1689 short il_next;
1690 short pref_node_fork;
1691#endif
1692#ifdef CONFIG_NUMA_BALANCING
1693 int numa_scan_seq;
1694 unsigned int numa_scan_period;
1695 unsigned int numa_scan_period_max;
1696 int numa_preferred_nid;
1697 unsigned long numa_migrate_retry;
1698 u64 node_stamp; /* migration stamp */
1699 u64 last_task_numa_placement;
1700 u64 last_sum_exec_runtime;
1701 struct callback_head numa_work;
1702
1703 struct list_head numa_entry;
1704 struct numa_group *numa_group;
1705
1706 /*
1707 * numa_faults is an array split into four regions:
1708 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1709 * in this precise order.
1710 *
1711 * faults_memory: Exponential decaying average of faults on a per-node
1712 * basis. Scheduling placement decisions are made based on these
1713 * counts. The values remain static for the duration of a PTE scan.
1714 * faults_cpu: Track the nodes the process was running on when a NUMA
1715 * hinting fault was incurred.
1716 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1717 * during the current scan window. When the scan completes, the counts
1718 * in faults_memory and faults_cpu decay and these values are copied.
1719 */
1720 unsigned long *numa_faults;
1721 unsigned long total_numa_faults;
1722
1723 /*
1724 * numa_faults_locality tracks if faults recorded during the last
1725 * scan window were remote/local or failed to migrate. The task scan
1726 * period is adapted based on the locality of the faults with different
1727 * weights depending on whether they were shared or private faults
1728 */
1729 unsigned long numa_faults_locality[3];
1730
1731 unsigned long numa_pages_migrated;
1732#endif /* CONFIG_NUMA_BALANCING */
1733
1734#ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
1735 struct tlbflush_unmap_batch tlb_ubc;
1736#endif
1737
1738 struct rcu_head rcu;
1739
1740 /*
1741 * cache last used pipe for splice
1742 */
1743 struct pipe_inode_info *splice_pipe;
1744
1745 struct page_frag task_frag;
1746
1747#ifdef CONFIG_TASK_DELAY_ACCT
1748 struct task_delay_info *delays;
1749#endif
1750#ifdef CONFIG_FAULT_INJECTION
1751 int make_it_fail;
1752#endif
1753 /*
1754 * when (nr_dirtied >= nr_dirtied_pause), it's time to call
1755 * balance_dirty_pages() for some dirty throttling pause
1756 */
1757 int nr_dirtied;
1758 int nr_dirtied_pause;
1759 unsigned long dirty_paused_when; /* start of a write-and-pause period */
1760
1761#ifdef CONFIG_LATENCYTOP
1762 int latency_record_count;
1763 struct latency_record latency_record[LT_SAVECOUNT];
1764#endif
1765 /*
1766 * time slack values; these are used to round up poll() and
1767 * select() etc timeout values. These are in nanoseconds.
1768 */
1769 unsigned long timer_slack_ns;
1770 unsigned long default_timer_slack_ns;
1771
1772#ifdef CONFIG_KASAN
1773 unsigned int kasan_depth;
1774#endif
1775#ifdef CONFIG_FUNCTION_GRAPH_TRACER
1776 /* Index of current stored address in ret_stack */
1777 int curr_ret_stack;
1778 /* Stack of return addresses for return function tracing */
1779 struct ftrace_ret_stack *ret_stack;
1780 /* time stamp for last schedule */
1781 unsigned long long ftrace_timestamp;
1782 /*
1783 * Number of functions that haven't been traced
1784 * because of depth overrun.
1785 */
1786 atomic_t trace_overrun;
1787 /* Pause for the tracing */
1788 atomic_t tracing_graph_pause;
1789#endif
1790#ifdef CONFIG_TRACING
1791 /* state flags for use by tracers */
1792 unsigned long trace;
1793 /* bitmask and counter of trace recursion */
1794 unsigned long trace_recursion;
1795#endif /* CONFIG_TRACING */
1796#ifdef CONFIG_MEMCG
1797 struct mem_cgroup *memcg_in_oom;
1798 gfp_t memcg_oom_gfp_mask;
1799 int memcg_oom_order;
1800
1801 /* number of pages to reclaim on returning to userland */
1802 unsigned int memcg_nr_pages_over_high;
1803#endif
1804#ifdef CONFIG_UPROBES
1805 struct uprobe_task *utask;
1806#endif
1807#if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1808 unsigned int sequential_io;
1809 unsigned int sequential_io_avg;
1810#endif
1811#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1812 unsigned long task_state_change;
1813#endif
1814 int pagefault_disabled;
1815/* CPU-specific state of this task */
1816 struct thread_struct thread;
1817/*
1818 * WARNING: on x86, 'thread_struct' contains a variable-sized
1819 * structure. It *MUST* be at the end of 'task_struct'.
1820 *
1821 * Do not put anything below here!
1822 */
1823};
1824
1825#ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
1826extern int arch_task_struct_size __read_mostly;
1827#else
1828# define arch_task_struct_size (sizeof(struct task_struct))
1829#endif
1830
1831/* Future-safe accessor for struct task_struct's cpus_allowed. */
1832#define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
1833
1834#define TNF_MIGRATED 0x01
1835#define TNF_NO_GROUP 0x02
1836#define TNF_SHARED 0x04
1837#define TNF_FAULT_LOCAL 0x08
1838#define TNF_MIGRATE_FAIL 0x10
1839
1840#ifdef CONFIG_NUMA_BALANCING
1841extern void task_numa_fault(int last_node, int node, int pages, int flags);
1842extern pid_t task_numa_group_id(struct task_struct *p);
1843extern void set_numabalancing_state(bool enabled);
1844extern void task_numa_free(struct task_struct *p);
1845extern bool should_numa_migrate_memory(struct task_struct *p, struct page *page,
1846 int src_nid, int dst_cpu);
1847#else
1848static inline void task_numa_fault(int last_node, int node, int pages,
1849 int flags)
1850{
1851}
1852static inline pid_t task_numa_group_id(struct task_struct *p)
1853{
1854 return 0;
1855}
1856static inline void set_numabalancing_state(bool enabled)
1857{
1858}
1859static inline void task_numa_free(struct task_struct *p)
1860{
1861}
1862static inline bool should_numa_migrate_memory(struct task_struct *p,
1863 struct page *page, int src_nid, int dst_cpu)
1864{
1865 return true;
1866}
1867#endif
1868
1869static inline struct pid *task_pid(struct task_struct *task)
1870{
1871 return task->pids[PIDTYPE_PID].pid;
1872}
1873
1874static inline struct pid *task_tgid(struct task_struct *task)
1875{
1876 return task->group_leader->pids[PIDTYPE_PID].pid;
1877}
1878
1879/*
1880 * Without tasklist or rcu lock it is not safe to dereference
1881 * the result of task_pgrp/task_session even if task == current,
1882 * we can race with another thread doing sys_setsid/sys_setpgid.
1883 */
1884static inline struct pid *task_pgrp(struct task_struct *task)
1885{
1886 return task->group_leader->pids[PIDTYPE_PGID].pid;
1887}
1888
1889static inline struct pid *task_session(struct task_struct *task)
1890{
1891 return task->group_leader->pids[PIDTYPE_SID].pid;
1892}
1893
1894struct pid_namespace;
1895
1896/*
1897 * the helpers to get the task's different pids as they are seen
1898 * from various namespaces
1899 *
1900 * task_xid_nr() : global id, i.e. the id seen from the init namespace;
1901 * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of
1902 * current.
1903 * task_xid_nr_ns() : id seen from the ns specified;
1904 *
1905 * set_task_vxid() : assigns a virtual id to a task;
1906 *
1907 * see also pid_nr() etc in include/linux/pid.h
1908 */
1909pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
1910 struct pid_namespace *ns);
1911
1912static inline pid_t task_pid_nr(struct task_struct *tsk)
1913{
1914 return tsk->pid;
1915}
1916
1917static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
1918 struct pid_namespace *ns)
1919{
1920 return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1921}
1922
1923static inline pid_t task_pid_vnr(struct task_struct *tsk)
1924{
1925 return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1926}
1927
1928
1929static inline pid_t task_tgid_nr(struct task_struct *tsk)
1930{
1931 return tsk->tgid;
1932}
1933
1934pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1935
1936static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1937{
1938 return pid_vnr(task_tgid(tsk));
1939}
1940
1941
1942static inline int pid_alive(const struct task_struct *p);
1943static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1944{
1945 pid_t pid = 0;
1946
1947 rcu_read_lock();
1948 if (pid_alive(tsk))
1949 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1950 rcu_read_unlock();
1951
1952 return pid;
1953}
1954
1955static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1956{
1957 return task_ppid_nr_ns(tsk, &init_pid_ns);
1958}
1959
1960static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
1961 struct pid_namespace *ns)
1962{
1963 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1964}
1965
1966static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1967{
1968 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1969}
1970
1971
1972static inline pid_t task_session_nr_ns(struct task_struct *tsk,
1973 struct pid_namespace *ns)
1974{
1975 return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1976}
1977
1978static inline pid_t task_session_vnr(struct task_struct *tsk)
1979{
1980 return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1981}
1982
1983/* obsolete, do not use */
1984static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1985{
1986 return task_pgrp_nr_ns(tsk, &init_pid_ns);
1987}
1988
1989/**
1990 * pid_alive - check that a task structure is not stale
1991 * @p: Task structure to be checked.
1992 *
1993 * Test if a process is not yet dead (at most zombie state)
1994 * If pid_alive fails, then pointers within the task structure
1995 * can be stale and must not be dereferenced.
1996 *
1997 * Return: 1 if the process is alive. 0 otherwise.
1998 */
1999static inline int pid_alive(const struct task_struct *p)
2000{
2001 return p->pids[PIDTYPE_PID].pid != NULL;
2002}
2003
2004/**
2005 * is_global_init - check if a task structure is init
2006 * @tsk: Task structure to be checked.
2007 *
2008 * Check if a task structure is the first user space task the kernel created.
2009 *
2010 * Return: 1 if the task structure is init. 0 otherwise.
2011 */
2012static inline int is_global_init(struct task_struct *tsk)
2013{
2014 return tsk->pid == 1;
2015}
2016
2017extern struct pid *cad_pid;
2018
2019extern void free_task(struct task_struct *tsk);
2020#define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
2021
2022extern void __put_task_struct(struct task_struct *t);
2023
2024static inline void put_task_struct(struct task_struct *t)
2025{
2026 if (atomic_dec_and_test(&t->usage))
2027 __put_task_struct(t);
2028}
2029
2030#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
2031extern void task_cputime(struct task_struct *t,
2032 cputime_t *utime, cputime_t *stime);
2033extern void task_cputime_scaled(struct task_struct *t,
2034 cputime_t *utimescaled, cputime_t *stimescaled);
2035extern cputime_t task_gtime(struct task_struct *t);
2036#else
2037static inline void task_cputime(struct task_struct *t,
2038 cputime_t *utime, cputime_t *stime)
2039{
2040 if (utime)
2041 *utime = t->utime;
2042 if (stime)
2043 *stime = t->stime;
2044}
2045
2046static inline void task_cputime_scaled(struct task_struct *t,
2047 cputime_t *utimescaled,
2048 cputime_t *stimescaled)
2049{
2050 if (utimescaled)
2051 *utimescaled = t->utimescaled;
2052 if (stimescaled)
2053 *stimescaled = t->stimescaled;
2054}
2055
2056static inline cputime_t task_gtime(struct task_struct *t)
2057{
2058 return t->gtime;
2059}
2060#endif
2061extern void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
2062extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
2063
2064/*
2065 * Per process flags
2066 */
2067#define PF_EXITING 0x00000004 /* getting shut down */
2068#define PF_EXITPIDONE 0x00000008 /* pi exit done on shut down */
2069#define PF_VCPU 0x00000010 /* I'm a virtual CPU */
2070#define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */
2071#define PF_FORKNOEXEC 0x00000040 /* forked but didn't exec */
2072#define PF_MCE_PROCESS 0x00000080 /* process policy on mce errors */
2073#define PF_SUPERPRIV 0x00000100 /* used super-user privileges */
2074#define PF_DUMPCORE 0x00000200 /* dumped core */
2075#define PF_SIGNALED 0x00000400 /* killed by a signal */
2076#define PF_MEMALLOC 0x00000800 /* Allocating memory */
2077#define PF_NPROC_EXCEEDED 0x00001000 /* set_user noticed that RLIMIT_NPROC was exceeded */
2078#define PF_USED_MATH 0x00002000 /* if unset the fpu must be initialized before use */
2079#define PF_USED_ASYNC 0x00004000 /* used async_schedule*(), used by module init */
2080#define PF_NOFREEZE 0x00008000 /* this thread should not be frozen */
2081#define PF_FROZEN 0x00010000 /* frozen for system suspend */
2082#define PF_FSTRANS 0x00020000 /* inside a filesystem transaction */
2083#define PF_KSWAPD 0x00040000 /* I am kswapd */
2084#define PF_MEMALLOC_NOIO 0x00080000 /* Allocating memory without IO involved */
2085#define PF_LESS_THROTTLE 0x00100000 /* Throttle me less: I clean memory */
2086#define PF_KTHREAD 0x00200000 /* I am a kernel thread */
2087#define PF_RANDOMIZE 0x00400000 /* randomize virtual address space */
2088#define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */
2089#define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_allowed */
2090#define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */
2091#define PF_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */
2092#define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezable */
2093#define PF_SUSPEND_TASK 0x80000000 /* this thread called freeze_processes and should not be frozen */
2094
2095/*
2096 * Only the _current_ task can read/write to tsk->flags, but other
2097 * tasks can access tsk->flags in readonly mode for example
2098 * with tsk_used_math (like during threaded core dumping).
2099 * There is however an exception to this rule during ptrace
2100 * or during fork: the ptracer task is allowed to write to the
2101 * child->flags of its traced child (same goes for fork, the parent
2102 * can write to the child->flags), because we're guaranteed the
2103 * child is not running and in turn not changing child->flags
2104 * at the same time the parent does it.
2105 */
2106#define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
2107#define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
2108#define clear_used_math() clear_stopped_child_used_math(current)
2109#define set_used_math() set_stopped_child_used_math(current)
2110#define conditional_stopped_child_used_math(condition, child) \
2111 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
2112#define conditional_used_math(condition) \
2113 conditional_stopped_child_used_math(condition, current)
2114#define copy_to_stopped_child_used_math(child) \
2115 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
2116/* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
2117#define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
2118#define used_math() tsk_used_math(current)
2119
2120/* __GFP_IO isn't allowed if PF_MEMALLOC_NOIO is set in current->flags
2121 * __GFP_FS is also cleared as it implies __GFP_IO.
2122 */
2123static inline gfp_t memalloc_noio_flags(gfp_t flags)
2124{
2125 if (unlikely(current->flags & PF_MEMALLOC_NOIO))
2126 flags &= ~(__GFP_IO | __GFP_FS);
2127 return flags;
2128}
2129
2130static inline unsigned int memalloc_noio_save(void)
2131{
2132 unsigned int flags = current->flags & PF_MEMALLOC_NOIO;
2133 current->flags |= PF_MEMALLOC_NOIO;
2134 return flags;
2135}
2136
2137static inline void memalloc_noio_restore(unsigned int flags)
2138{
2139 current->flags = (current->flags & ~PF_MEMALLOC_NOIO) | flags;
2140}
2141
2142/* Per-process atomic flags. */
2143#define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */
2144#define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */
2145#define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */
2146
2147
2148#define TASK_PFA_TEST(name, func) \
2149 static inline bool task_##func(struct task_struct *p) \
2150 { return test_bit(PFA_##name, &p->atomic_flags); }
2151#define TASK_PFA_SET(name, func) \
2152 static inline void task_set_##func(struct task_struct *p) \
2153 { set_bit(PFA_##name, &p->atomic_flags); }
2154#define TASK_PFA_CLEAR(name, func) \
2155 static inline void task_clear_##func(struct task_struct *p) \
2156 { clear_bit(PFA_##name, &p->atomic_flags); }
2157
2158TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
2159TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
2160
2161TASK_PFA_TEST(SPREAD_PAGE, spread_page)
2162TASK_PFA_SET(SPREAD_PAGE, spread_page)
2163TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
2164
2165TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
2166TASK_PFA_SET(SPREAD_SLAB, spread_slab)
2167TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
2168
2169/*
2170 * task->jobctl flags
2171 */
2172#define JOBCTL_STOP_SIGMASK 0xffff /* signr of the last group stop */
2173
2174#define JOBCTL_STOP_DEQUEUED_BIT 16 /* stop signal dequeued */
2175#define JOBCTL_STOP_PENDING_BIT 17 /* task should stop for group stop */
2176#define JOBCTL_STOP_CONSUME_BIT 18 /* consume group stop count */
2177#define JOBCTL_TRAP_STOP_BIT 19 /* trap for STOP */
2178#define JOBCTL_TRAP_NOTIFY_BIT 20 /* trap for NOTIFY */
2179#define JOBCTL_TRAPPING_BIT 21 /* switching to TRACED */
2180#define JOBCTL_LISTENING_BIT 22 /* ptracer is listening for events */
2181
2182#define JOBCTL_STOP_DEQUEUED (1UL << JOBCTL_STOP_DEQUEUED_BIT)
2183#define JOBCTL_STOP_PENDING (1UL << JOBCTL_STOP_PENDING_BIT)
2184#define JOBCTL_STOP_CONSUME (1UL << JOBCTL_STOP_CONSUME_BIT)
2185#define JOBCTL_TRAP_STOP (1UL << JOBCTL_TRAP_STOP_BIT)
2186#define JOBCTL_TRAP_NOTIFY (1UL << JOBCTL_TRAP_NOTIFY_BIT)
2187#define JOBCTL_TRAPPING (1UL << JOBCTL_TRAPPING_BIT)
2188#define JOBCTL_LISTENING (1UL << JOBCTL_LISTENING_BIT)
2189
2190#define JOBCTL_TRAP_MASK (JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
2191#define JOBCTL_PENDING_MASK (JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)
2192
2193extern bool task_set_jobctl_pending(struct task_struct *task,
2194 unsigned long mask);
2195extern void task_clear_jobctl_trapping(struct task_struct *task);
2196extern void task_clear_jobctl_pending(struct task_struct *task,
2197 unsigned long mask);
2198
2199static inline void rcu_copy_process(struct task_struct *p)
2200{
2201#ifdef CONFIG_PREEMPT_RCU
2202 p->rcu_read_lock_nesting = 0;
2203 p->rcu_read_unlock_special.s = 0;
2204 p->rcu_blocked_node = NULL;
2205 INIT_LIST_HEAD(&p->rcu_node_entry);
2206#endif /* #ifdef CONFIG_PREEMPT_RCU */
2207#ifdef CONFIG_TASKS_RCU
2208 p->rcu_tasks_holdout = false;
2209 INIT_LIST_HEAD(&p->rcu_tasks_holdout_list);
2210 p->rcu_tasks_idle_cpu = -1;
2211#endif /* #ifdef CONFIG_TASKS_RCU */
2212}
2213
2214static inline void tsk_restore_flags(struct task_struct *task,
2215 unsigned long orig_flags, unsigned long flags)
2216{
2217 task->flags &= ~flags;
2218 task->flags |= orig_flags & flags;
2219}
2220
2221extern int cpuset_cpumask_can_shrink(const struct cpumask *cur,
2222 const struct cpumask *trial);
2223extern int task_can_attach(struct task_struct *p,
2224 const struct cpumask *cs_cpus_allowed);
2225#ifdef CONFIG_SMP
2226extern void do_set_cpus_allowed(struct task_struct *p,
2227 const struct cpumask *new_mask);
2228
2229extern int set_cpus_allowed_ptr(struct task_struct *p,
2230 const struct cpumask *new_mask);
2231#else
2232static inline void do_set_cpus_allowed(struct task_struct *p,
2233 const struct cpumask *new_mask)
2234{
2235}
2236static inline int set_cpus_allowed_ptr(struct task_struct *p,
2237 const struct cpumask *new_mask)
2238{
2239 if (!cpumask_test_cpu(0, new_mask))
2240 return -EINVAL;
2241 return 0;
2242}
2243#endif
2244
2245#ifdef CONFIG_NO_HZ_COMMON
2246void calc_load_enter_idle(void);
2247void calc_load_exit_idle(void);
2248#else
2249static inline void calc_load_enter_idle(void) { }
2250static inline void calc_load_exit_idle(void) { }
2251#endif /* CONFIG_NO_HZ_COMMON */
2252
2253/*
2254 * Do not use outside of architecture code which knows its limitations.
2255 *
2256 * sched_clock() has no promise of monotonicity or bounded drift between
2257 * CPUs, use (which you should not) requires disabling IRQs.
2258 *
2259 * Please use one of the three interfaces below.
2260 */
2261extern unsigned long long notrace sched_clock(void);
2262/*
2263 * See the comment in kernel/sched/clock.c
2264 */
2265extern u64 cpu_clock(int cpu);
2266extern u64 local_clock(void);
2267extern u64 running_clock(void);
2268extern u64 sched_clock_cpu(int cpu);
2269
2270
2271extern void sched_clock_init(void);
2272
2273#ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
2274static inline void sched_clock_tick(void)
2275{
2276}
2277
2278static inline void sched_clock_idle_sleep_event(void)
2279{
2280}
2281
2282static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
2283{
2284}
2285#else
2286/*
2287 * Architectures can set this to 1 if they have specified
2288 * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
2289 * but then during bootup it turns out that sched_clock()
2290 * is reliable after all:
2291 */
2292extern int sched_clock_stable(void);
2293extern void set_sched_clock_stable(void);
2294extern void clear_sched_clock_stable(void);
2295
2296extern void sched_clock_tick(void);
2297extern void sched_clock_idle_sleep_event(void);
2298extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2299#endif
2300
2301#ifdef CONFIG_IRQ_TIME_ACCOUNTING
2302/*
2303 * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
2304 * The reason for this explicit opt-in is not to have perf penalty with
2305 * slow sched_clocks.
2306 */
2307extern void enable_sched_clock_irqtime(void);
2308extern void disable_sched_clock_irqtime(void);
2309#else
2310static inline void enable_sched_clock_irqtime(void) {}
2311static inline void disable_sched_clock_irqtime(void) {}
2312#endif
2313
2314extern unsigned long long
2315task_sched_runtime(struct task_struct *task);
2316
2317/* sched_exec is called by processes performing an exec */
2318#ifdef CONFIG_SMP
2319extern void sched_exec(void);
2320#else
2321#define sched_exec() {}
2322#endif
2323
2324extern void sched_clock_idle_sleep_event(void);
2325extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2326
2327#ifdef CONFIG_HOTPLUG_CPU
2328extern void idle_task_exit(void);
2329#else
2330static inline void idle_task_exit(void) {}
2331#endif
2332
2333#if defined(CONFIG_NO_HZ_COMMON) && defined(CONFIG_SMP)
2334extern void wake_up_nohz_cpu(int cpu);
2335#else
2336static inline void wake_up_nohz_cpu(int cpu) { }
2337#endif
2338
2339#ifdef CONFIG_NO_HZ_FULL
2340extern bool sched_can_stop_tick(void);
2341extern u64 scheduler_tick_max_deferment(void);
2342#else
2343static inline bool sched_can_stop_tick(void) { return false; }
2344#endif
2345
2346#ifdef CONFIG_SCHED_AUTOGROUP
2347extern void sched_autogroup_create_attach(struct task_struct *p);
2348extern void sched_autogroup_detach(struct task_struct *p);
2349extern void sched_autogroup_fork(struct signal_struct *sig);
2350extern void sched_autogroup_exit(struct signal_struct *sig);
2351#ifdef CONFIG_PROC_FS
2352extern void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m);
2353extern int proc_sched_autogroup_set_nice(struct task_struct *p, int nice);
2354#endif
2355#else
2356static inline void sched_autogroup_create_attach(struct task_struct *p) { }
2357static inline void sched_autogroup_detach(struct task_struct *p) { }
2358static inline void sched_autogroup_fork(struct signal_struct *sig) { }
2359static inline void sched_autogroup_exit(struct signal_struct *sig) { }
2360#endif
2361
2362extern int yield_to(struct task_struct *p, bool preempt);
2363extern void set_user_nice(struct task_struct *p, long nice);
2364extern int task_prio(const struct task_struct *p);
2365/**
2366 * task_nice - return the nice value of a given task.
2367 * @p: the task in question.
2368 *
2369 * Return: The nice value [ -20 ... 0 ... 19 ].
2370 */
2371static inline int task_nice(const struct task_struct *p)
2372{
2373 return PRIO_TO_NICE((p)->static_prio);
2374}
2375extern int can_nice(const struct task_struct *p, const int nice);
2376extern int task_curr(const struct task_struct *p);
2377extern int idle_cpu(int cpu);
2378extern int sched_setscheduler(struct task_struct *, int,
2379 const struct sched_param *);
2380extern int sched_setscheduler_nocheck(struct task_struct *, int,
2381 const struct sched_param *);
2382extern int sched_setattr(struct task_struct *,
2383 const struct sched_attr *);
2384extern struct task_struct *idle_task(int cpu);
2385/**
2386 * is_idle_task - is the specified task an idle task?
2387 * @p: the task in question.
2388 *
2389 * Return: 1 if @p is an idle task. 0 otherwise.
2390 */
2391static inline bool is_idle_task(const struct task_struct *p)
2392{
2393 return p->pid == 0;
2394}
2395extern struct task_struct *curr_task(int cpu);
2396extern void set_curr_task(int cpu, struct task_struct *p);
2397
2398void yield(void);
2399
2400union thread_union {
2401 struct thread_info thread_info;
2402 unsigned long stack[THREAD_SIZE/sizeof(long)];
2403};
2404
2405#ifndef __HAVE_ARCH_KSTACK_END
2406static inline int kstack_end(void *addr)
2407{
2408 /* Reliable end of stack detection:
2409 * Some APM bios versions misalign the stack
2410 */
2411 return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
2412}
2413#endif
2414
2415extern union thread_union init_thread_union;
2416extern struct task_struct init_task;
2417
2418extern struct mm_struct init_mm;
2419
2420extern struct pid_namespace init_pid_ns;
2421
2422/*
2423 * find a task by one of its numerical ids
2424 *
2425 * find_task_by_pid_ns():
2426 * finds a task by its pid in the specified namespace
2427 * find_task_by_vpid():
2428 * finds a task by its virtual pid
2429 *
2430 * see also find_vpid() etc in include/linux/pid.h
2431 */
2432
2433extern struct task_struct *find_task_by_vpid(pid_t nr);
2434extern struct task_struct *find_task_by_pid_ns(pid_t nr,
2435 struct pid_namespace *ns);
2436
2437/* per-UID process charging. */
2438extern struct user_struct * alloc_uid(kuid_t);
2439static inline struct user_struct *get_uid(struct user_struct *u)
2440{
2441 atomic_inc(&u->__count);
2442 return u;
2443}
2444extern void free_uid(struct user_struct *);
2445
2446#include <asm/current.h>
2447
2448extern void xtime_update(unsigned long ticks);
2449
2450extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2451extern int wake_up_process(struct task_struct *tsk);
2452extern void wake_up_new_task(struct task_struct *tsk);
2453#ifdef CONFIG_SMP
2454 extern void kick_process(struct task_struct *tsk);
2455#else
2456 static inline void kick_process(struct task_struct *tsk) { }
2457#endif
2458extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
2459extern void sched_dead(struct task_struct *p);
2460
2461extern void proc_caches_init(void);
2462extern void flush_signals(struct task_struct *);
2463extern void ignore_signals(struct task_struct *);
2464extern void flush_signal_handlers(struct task_struct *, int force_default);
2465extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
2466
2467static inline int kernel_dequeue_signal(siginfo_t *info)
2468{
2469 struct task_struct *tsk = current;
2470 siginfo_t __info;
2471 int ret;
2472
2473 spin_lock_irq(&tsk->sighand->siglock);
2474 ret = dequeue_signal(tsk, &tsk->blocked, info ?: &__info);
2475 spin_unlock_irq(&tsk->sighand->siglock);
2476
2477 return ret;
2478}
2479
2480static inline void kernel_signal_stop(void)
2481{
2482 spin_lock_irq(&current->sighand->siglock);
2483 if (current->jobctl & JOBCTL_STOP_DEQUEUED)
2484 __set_current_state(TASK_STOPPED);
2485 spin_unlock_irq(&current->sighand->siglock);
2486
2487 schedule();
2488}
2489
2490extern void release_task(struct task_struct * p);
2491extern int send_sig_info(int, struct siginfo *, struct task_struct *);
2492extern int force_sigsegv(int, struct task_struct *);
2493extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2494extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
2495extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2496extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *,
2497 const struct cred *, u32);
2498extern int kill_pgrp(struct pid *pid, int sig, int priv);
2499extern int kill_pid(struct pid *pid, int sig, int priv);
2500extern int kill_proc_info(int, struct siginfo *, pid_t);
2501extern __must_check bool do_notify_parent(struct task_struct *, int);
2502extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
2503extern void force_sig(int, struct task_struct *);
2504extern int send_sig(int, struct task_struct *, int);
2505extern int zap_other_threads(struct task_struct *p);
2506extern struct sigqueue *sigqueue_alloc(void);
2507extern void sigqueue_free(struct sigqueue *);
2508extern int send_sigqueue(struct sigqueue *, struct task_struct *, int group);
2509extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
2510
2511static inline void restore_saved_sigmask(void)
2512{
2513 if (test_and_clear_restore_sigmask())
2514 __set_current_blocked(&current->saved_sigmask);
2515}
2516
2517static inline sigset_t *sigmask_to_save(void)
2518{
2519 sigset_t *res = &current->blocked;
2520 if (unlikely(test_restore_sigmask()))
2521 res = &current->saved_sigmask;
2522 return res;
2523}
2524
2525static inline int kill_cad_pid(int sig, int priv)
2526{
2527 return kill_pid(cad_pid, sig, priv);
2528}
2529
2530/* These can be the second arg to send_sig_info/send_group_sig_info. */
2531#define SEND_SIG_NOINFO ((struct siginfo *) 0)
2532#define SEND_SIG_PRIV ((struct siginfo *) 1)
2533#define SEND_SIG_FORCED ((struct siginfo *) 2)
2534
2535/*
2536 * True if we are on the alternate signal stack.
2537 */
2538static inline int on_sig_stack(unsigned long sp)
2539{
2540#ifdef CONFIG_STACK_GROWSUP
2541 return sp >= current->sas_ss_sp &&
2542 sp - current->sas_ss_sp < current->sas_ss_size;
2543#else
2544 return sp > current->sas_ss_sp &&
2545 sp - current->sas_ss_sp <= current->sas_ss_size;
2546#endif
2547}
2548
2549static inline int sas_ss_flags(unsigned long sp)
2550{
2551 if (!current->sas_ss_size)
2552 return SS_DISABLE;
2553
2554 return on_sig_stack(sp) ? SS_ONSTACK : 0;
2555}
2556
2557static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig)
2558{
2559 if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))
2560#ifdef CONFIG_STACK_GROWSUP
2561 return current->sas_ss_sp;
2562#else
2563 return current->sas_ss_sp + current->sas_ss_size;
2564#endif
2565 return sp;
2566}
2567
2568/*
2569 * Routines for handling mm_structs
2570 */
2571extern struct mm_struct * mm_alloc(void);
2572
2573/* mmdrop drops the mm and the page tables */
2574extern void __mmdrop(struct mm_struct *);
2575static inline void mmdrop(struct mm_struct * mm)
2576{
2577 if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2578 __mmdrop(mm);
2579}
2580
2581/* mmput gets rid of the mappings and all user-space */
2582extern void mmput(struct mm_struct *);
2583/* Grab a reference to a task's mm, if it is not already going away */
2584extern struct mm_struct *get_task_mm(struct task_struct *task);
2585/*
2586 * Grab a reference to a task's mm, if it is not already going away
2587 * and ptrace_may_access with the mode parameter passed to it
2588 * succeeds.
2589 */
2590extern struct mm_struct *mm_access(struct task_struct *task, unsigned int mode);
2591/* Remove the current tasks stale references to the old mm_struct */
2592extern void mm_release(struct task_struct *, struct mm_struct *);
2593
2594#ifdef CONFIG_HAVE_COPY_THREAD_TLS
2595extern int copy_thread_tls(unsigned long, unsigned long, unsigned long,
2596 struct task_struct *, unsigned long);
2597#else
2598extern int copy_thread(unsigned long, unsigned long, unsigned long,
2599 struct task_struct *);
2600
2601/* Architectures that haven't opted into copy_thread_tls get the tls argument
2602 * via pt_regs, so ignore the tls argument passed via C. */
2603static inline int copy_thread_tls(
2604 unsigned long clone_flags, unsigned long sp, unsigned long arg,
2605 struct task_struct *p, unsigned long tls)
2606{
2607 return copy_thread(clone_flags, sp, arg, p);
2608}
2609#endif
2610extern void flush_thread(void);
2611extern void exit_thread(void);
2612
2613extern void exit_files(struct task_struct *);
2614extern void __cleanup_sighand(struct sighand_struct *);
2615
2616extern void exit_itimers(struct signal_struct *);
2617extern void flush_itimer_signals(void);
2618
2619extern void do_group_exit(int);
2620
2621extern int do_execve(struct filename *,
2622 const char __user * const __user *,
2623 const char __user * const __user *);
2624extern int do_execveat(int, struct filename *,
2625 const char __user * const __user *,
2626 const char __user * const __user *,
2627 int);
2628extern long _do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *, unsigned long);
2629extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
2630struct task_struct *fork_idle(int);
2631extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
2632
2633extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
2634static inline void set_task_comm(struct task_struct *tsk, const char *from)
2635{
2636 __set_task_comm(tsk, from, false);
2637}
2638extern char *get_task_comm(char *to, struct task_struct *tsk);
2639
2640#ifdef CONFIG_SMP
2641void scheduler_ipi(void);
2642extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
2643#else
2644static inline void scheduler_ipi(void) { }
2645static inline unsigned long wait_task_inactive(struct task_struct *p,
2646 long match_state)
2647{
2648 return 1;
2649}
2650#endif
2651
2652#define tasklist_empty() \
2653 list_empty(&init_task.tasks)
2654
2655#define next_task(p) \
2656 list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
2657
2658#define for_each_process(p) \
2659 for (p = &init_task ; (p = next_task(p)) != &init_task ; )
2660
2661extern bool current_is_single_threaded(void);
2662
2663/*
2664 * Careful: do_each_thread/while_each_thread is a double loop so
2665 * 'break' will not work as expected - use goto instead.
2666 */
2667#define do_each_thread(g, t) \
2668 for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
2669
2670#define while_each_thread(g, t) \
2671 while ((t = next_thread(t)) != g)
2672
2673#define __for_each_thread(signal, t) \
2674 list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node)
2675
2676#define for_each_thread(p, t) \
2677 __for_each_thread((p)->signal, t)
2678
2679/* Careful: this is a double loop, 'break' won't work as expected. */
2680#define for_each_process_thread(p, t) \
2681 for_each_process(p) for_each_thread(p, t)
2682
2683static inline int get_nr_threads(struct task_struct *tsk)
2684{
2685 return tsk->signal->nr_threads;
2686}
2687
2688static inline bool thread_group_leader(struct task_struct *p)
2689{
2690 return p->exit_signal >= 0;
2691}
2692
2693/* Do to the insanities of de_thread it is possible for a process
2694 * to have the pid of the thread group leader without actually being
2695 * the thread group leader. For iteration through the pids in proc
2696 * all we care about is that we have a task with the appropriate
2697 * pid, we don't actually care if we have the right task.
2698 */
2699static inline bool has_group_leader_pid(struct task_struct *p)
2700{
2701 return task_pid(p) == p->signal->leader_pid;
2702}
2703
2704static inline
2705bool same_thread_group(struct task_struct *p1, struct task_struct *p2)
2706{
2707 return p1->signal == p2->signal;
2708}
2709
2710static inline struct task_struct *next_thread(const struct task_struct *p)
2711{
2712 return list_entry_rcu(p->thread_group.next,
2713 struct task_struct, thread_group);
2714}
2715
2716static inline int thread_group_empty(struct task_struct *p)
2717{
2718 return list_empty(&p->thread_group);
2719}
2720
2721#define delay_group_leader(p) \
2722 (thread_group_leader(p) && !thread_group_empty(p))
2723
2724/*
2725 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
2726 * subscriptions and synchronises with wait4(). Also used in procfs. Also
2727 * pins the final release of task.io_context. Also protects ->cpuset and
2728 * ->cgroup.subsys[]. And ->vfork_done.
2729 *
2730 * Nests both inside and outside of read_lock(&tasklist_lock).
2731 * It must not be nested with write_lock_irq(&tasklist_lock),
2732 * neither inside nor outside.
2733 */
2734static inline void task_lock(struct task_struct *p)
2735{
2736 spin_lock(&p->alloc_lock);
2737}
2738
2739static inline void task_unlock(struct task_struct *p)
2740{
2741 spin_unlock(&p->alloc_lock);
2742}
2743
2744extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
2745 unsigned long *flags);
2746
2747static inline struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
2748 unsigned long *flags)
2749{
2750 struct sighand_struct *ret;
2751
2752 ret = __lock_task_sighand(tsk, flags);
2753 (void)__cond_lock(&tsk->sighand->siglock, ret);
2754 return ret;
2755}
2756
2757static inline void unlock_task_sighand(struct task_struct *tsk,
2758 unsigned long *flags)
2759{
2760 spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
2761}
2762
2763/**
2764 * threadgroup_change_begin - mark the beginning of changes to a threadgroup
2765 * @tsk: task causing the changes
2766 *
2767 * All operations which modify a threadgroup - a new thread joining the
2768 * group, death of a member thread (the assertion of PF_EXITING) and
2769 * exec(2) dethreading the process and replacing the leader - are wrapped
2770 * by threadgroup_change_{begin|end}(). This is to provide a place which
2771 * subsystems needing threadgroup stability can hook into for
2772 * synchronization.
2773 */
2774static inline void threadgroup_change_begin(struct task_struct *tsk)
2775{
2776 might_sleep();
2777 cgroup_threadgroup_change_begin(tsk);
2778}
2779
2780/**
2781 * threadgroup_change_end - mark the end of changes to a threadgroup
2782 * @tsk: task causing the changes
2783 *
2784 * See threadgroup_change_begin().
2785 */
2786static inline void threadgroup_change_end(struct task_struct *tsk)
2787{
2788 cgroup_threadgroup_change_end(tsk);
2789}
2790
2791#ifndef __HAVE_THREAD_FUNCTIONS
2792
2793#define task_thread_info(task) ((struct thread_info *)(task)->stack)
2794#define task_stack_page(task) ((task)->stack)
2795
2796static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
2797{
2798 *task_thread_info(p) = *task_thread_info(org);
2799 task_thread_info(p)->task = p;
2800}
2801
2802/*
2803 * Return the address of the last usable long on the stack.
2804 *
2805 * When the stack grows down, this is just above the thread
2806 * info struct. Going any lower will corrupt the threadinfo.
2807 *
2808 * When the stack grows up, this is the highest address.
2809 * Beyond that position, we corrupt data on the next page.
2810 */
2811static inline unsigned long *end_of_stack(struct task_struct *p)
2812{
2813#ifdef CONFIG_STACK_GROWSUP
2814 return (unsigned long *)((unsigned long)task_thread_info(p) + THREAD_SIZE) - 1;
2815#else
2816 return (unsigned long *)(task_thread_info(p) + 1);
2817#endif
2818}
2819
2820#endif
2821#define task_stack_end_corrupted(task) \
2822 (*(end_of_stack(task)) != STACK_END_MAGIC)
2823
2824static inline int object_is_on_stack(void *obj)
2825{
2826 void *stack = task_stack_page(current);
2827
2828 return (obj >= stack) && (obj < (stack + THREAD_SIZE));
2829}
2830
2831extern void thread_info_cache_init(void);
2832
2833#ifdef CONFIG_DEBUG_STACK_USAGE
2834static inline unsigned long stack_not_used(struct task_struct *p)
2835{
2836 unsigned long *n = end_of_stack(p);
2837
2838 do { /* Skip over canary */
2839 n++;
2840 } while (!*n);
2841
2842 return (unsigned long)n - (unsigned long)end_of_stack(p);
2843}
2844#endif
2845extern void set_task_stack_end_magic(struct task_struct *tsk);
2846
2847/* set thread flags in other task's structures
2848 * - see asm/thread_info.h for TIF_xxxx flags available
2849 */
2850static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2851{
2852 set_ti_thread_flag(task_thread_info(tsk), flag);
2853}
2854
2855static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2856{
2857 clear_ti_thread_flag(task_thread_info(tsk), flag);
2858}
2859
2860static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2861{
2862 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2863}
2864
2865static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2866{
2867 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2868}
2869
2870static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2871{
2872 return test_ti_thread_flag(task_thread_info(tsk), flag);
2873}
2874
2875static inline void set_tsk_need_resched(struct task_struct *tsk)
2876{
2877 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2878}
2879
2880static inline void clear_tsk_need_resched(struct task_struct *tsk)
2881{
2882 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2883}
2884
2885static inline int test_tsk_need_resched(struct task_struct *tsk)
2886{
2887 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2888}
2889
2890static inline int restart_syscall(void)
2891{
2892 set_tsk_thread_flag(current, TIF_SIGPENDING);
2893 return -ERESTARTNOINTR;
2894}
2895
2896static inline int signal_pending(struct task_struct *p)
2897{
2898 return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
2899}
2900
2901static inline int __fatal_signal_pending(struct task_struct *p)
2902{
2903 return unlikely(sigismember(&p->pending.signal, SIGKILL));
2904}
2905
2906static inline int fatal_signal_pending(struct task_struct *p)
2907{
2908 return signal_pending(p) && __fatal_signal_pending(p);
2909}
2910
2911static inline int signal_pending_state(long state, struct task_struct *p)
2912{
2913 if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
2914 return 0;
2915 if (!signal_pending(p))
2916 return 0;
2917
2918 return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
2919}
2920
2921/*
2922 * cond_resched() and cond_resched_lock(): latency reduction via
2923 * explicit rescheduling in places that are safe. The return
2924 * value indicates whether a reschedule was done in fact.
2925 * cond_resched_lock() will drop the spinlock before scheduling,
2926 * cond_resched_softirq() will enable bhs before scheduling.
2927 */
2928extern int _cond_resched(void);
2929
2930#define cond_resched() ({ \
2931 ___might_sleep(__FILE__, __LINE__, 0); \
2932 _cond_resched(); \
2933})
2934
2935extern int __cond_resched_lock(spinlock_t *lock);
2936
2937#define cond_resched_lock(lock) ({ \
2938 ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
2939 __cond_resched_lock(lock); \
2940})
2941
2942extern int __cond_resched_softirq(void);
2943
2944#define cond_resched_softirq() ({ \
2945 ___might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET); \
2946 __cond_resched_softirq(); \
2947})
2948
2949static inline void cond_resched_rcu(void)
2950{
2951#if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
2952 rcu_read_unlock();
2953 cond_resched();
2954 rcu_read_lock();
2955#endif
2956}
2957
2958/*
2959 * Does a critical section need to be broken due to another
2960 * task waiting?: (technically does not depend on CONFIG_PREEMPT,
2961 * but a general need for low latency)
2962 */
2963static inline int spin_needbreak(spinlock_t *lock)
2964{
2965#ifdef CONFIG_PREEMPT
2966 return spin_is_contended(lock);
2967#else
2968 return 0;
2969#endif
2970}
2971
2972/*
2973 * Idle thread specific functions to determine the need_resched
2974 * polling state.
2975 */
2976#ifdef TIF_POLLING_NRFLAG
2977static inline int tsk_is_polling(struct task_struct *p)
2978{
2979 return test_tsk_thread_flag(p, TIF_POLLING_NRFLAG);
2980}
2981
2982static inline void __current_set_polling(void)
2983{
2984 set_thread_flag(TIF_POLLING_NRFLAG);
2985}
2986
2987static inline bool __must_check current_set_polling_and_test(void)
2988{
2989 __current_set_polling();
2990
2991 /*
2992 * Polling state must be visible before we test NEED_RESCHED,
2993 * paired by resched_curr()
2994 */
2995 smp_mb__after_atomic();
2996
2997 return unlikely(tif_need_resched());
2998}
2999
3000static inline void __current_clr_polling(void)
3001{
3002 clear_thread_flag(TIF_POLLING_NRFLAG);
3003}
3004
3005static inline bool __must_check current_clr_polling_and_test(void)
3006{
3007 __current_clr_polling();
3008
3009 /*
3010 * Polling state must be visible before we test NEED_RESCHED,
3011 * paired by resched_curr()
3012 */
3013 smp_mb__after_atomic();
3014
3015 return unlikely(tif_need_resched());
3016}
3017
3018#else
3019static inline int tsk_is_polling(struct task_struct *p) { return 0; }
3020static inline void __current_set_polling(void) { }
3021static inline void __current_clr_polling(void) { }
3022
3023static inline bool __must_check current_set_polling_and_test(void)
3024{
3025 return unlikely(tif_need_resched());
3026}
3027static inline bool __must_check current_clr_polling_and_test(void)
3028{
3029 return unlikely(tif_need_resched());
3030}
3031#endif
3032
3033static inline void current_clr_polling(void)
3034{
3035 __current_clr_polling();
3036
3037 /*
3038 * Ensure we check TIF_NEED_RESCHED after we clear the polling bit.
3039 * Once the bit is cleared, we'll get IPIs with every new
3040 * TIF_NEED_RESCHED and the IPI handler, scheduler_ipi(), will also
3041 * fold.
3042 */
3043 smp_mb(); /* paired with resched_curr() */
3044
3045 preempt_fold_need_resched();
3046}
3047
3048static __always_inline bool need_resched(void)
3049{
3050 return unlikely(tif_need_resched());
3051}
3052
3053/*
3054 * Thread group CPU time accounting.
3055 */
3056void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
3057void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
3058
3059/*
3060 * Reevaluate whether the task has signals pending delivery.
3061 * Wake the task if so.
3062 * This is required every time the blocked sigset_t changes.
3063 * callers must hold sighand->siglock.
3064 */
3065extern void recalc_sigpending_and_wake(struct task_struct *t);
3066extern void recalc_sigpending(void);
3067
3068extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
3069
3070static inline void signal_wake_up(struct task_struct *t, bool resume)
3071{
3072 signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0);
3073}
3074static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
3075{
3076 signal_wake_up_state(t, resume ? __TASK_TRACED : 0);
3077}
3078
3079/*
3080 * Wrappers for p->thread_info->cpu access. No-op on UP.
3081 */
3082#ifdef CONFIG_SMP
3083
3084static inline unsigned int task_cpu(const struct task_struct *p)
3085{
3086 return task_thread_info(p)->cpu;
3087}
3088
3089static inline int task_node(const struct task_struct *p)
3090{
3091 return cpu_to_node(task_cpu(p));
3092}
3093
3094extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
3095
3096#else
3097
3098static inline unsigned int task_cpu(const struct task_struct *p)
3099{
3100 return 0;
3101}
3102
3103static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
3104{
3105}
3106
3107#endif /* CONFIG_SMP */
3108
3109extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
3110extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
3111
3112#ifdef CONFIG_CGROUP_SCHED
3113extern struct task_group root_task_group;
3114#endif /* CONFIG_CGROUP_SCHED */
3115
3116extern int task_can_switch_user(struct user_struct *up,
3117 struct task_struct *tsk);
3118
3119#ifdef CONFIG_TASK_XACCT
3120static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
3121{
3122 tsk->ioac.rchar += amt;
3123}
3124
3125static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
3126{
3127 tsk->ioac.wchar += amt;
3128}
3129
3130static inline void inc_syscr(struct task_struct *tsk)
3131{
3132 tsk->ioac.syscr++;
3133}
3134
3135static inline void inc_syscw(struct task_struct *tsk)
3136{
3137 tsk->ioac.syscw++;
3138}
3139#else
3140static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
3141{
3142}
3143
3144static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
3145{
3146}
3147
3148static inline void inc_syscr(struct task_struct *tsk)
3149{
3150}
3151
3152static inline void inc_syscw(struct task_struct *tsk)
3153{
3154}
3155#endif
3156
3157#ifndef TASK_SIZE_OF
3158#define TASK_SIZE_OF(tsk) TASK_SIZE
3159#endif
3160
3161#ifdef CONFIG_MEMCG
3162extern void mm_update_next_owner(struct mm_struct *mm);
3163#else
3164static inline void mm_update_next_owner(struct mm_struct *mm)
3165{
3166}
3167#endif /* CONFIG_MEMCG */
3168
3169static inline unsigned long task_rlimit(const struct task_struct *tsk,
3170 unsigned int limit)
3171{
3172 return READ_ONCE(tsk->signal->rlim[limit].rlim_cur);
3173}
3174
3175static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
3176 unsigned int limit)
3177{
3178 return READ_ONCE(tsk->signal->rlim[limit].rlim_max);
3179}
3180
3181static inline unsigned long rlimit(unsigned int limit)
3182{
3183 return task_rlimit(current, limit);
3184}
3185
3186static inline unsigned long rlimit_max(unsigned int limit)
3187{
3188 return task_rlimit_max(current, limit);
3189}
3190
3191#endif
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