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