sched.h revision 716a42348cdaf04534b15fbdc9c83e25baebfed5
1#ifndef _LINUX_SCHED_H
2#define _LINUX_SCHED_H
3
4/*
5 * cloning flags:
6 */
7#define CSIGNAL		0x000000ff	/* signal mask to be sent at exit */
8#define CLONE_VM	0x00000100	/* set if VM shared between processes */
9#define CLONE_FS	0x00000200	/* set if fs info shared between processes */
10#define CLONE_FILES	0x00000400	/* set if open files shared between processes */
11#define CLONE_SIGHAND	0x00000800	/* set if signal handlers and blocked signals shared */
12#define CLONE_PTRACE	0x00002000	/* set if we want to let tracing continue on the child too */
13#define CLONE_VFORK	0x00004000	/* set if the parent wants the child to wake it up on mm_release */
14#define CLONE_PARENT	0x00008000	/* set if we want to have the same parent as the cloner */
15#define CLONE_THREAD	0x00010000	/* Same thread group? */
16#define CLONE_NEWNS	0x00020000	/* New namespace group? */
17#define CLONE_SYSVSEM	0x00040000	/* share system V SEM_UNDO semantics */
18#define CLONE_SETTLS	0x00080000	/* create a new TLS for the child */
19#define CLONE_PARENT_SETTID	0x00100000	/* set the TID in the parent */
20#define CLONE_CHILD_CLEARTID	0x00200000	/* clear the TID in the child */
21#define CLONE_DETACHED		0x00400000	/* Unused, ignored */
22#define CLONE_UNTRACED		0x00800000	/* set if the tracing process can't force CLONE_PTRACE on this clone */
23#define CLONE_CHILD_SETTID	0x01000000	/* set the TID in the child */
24#define CLONE_STOPPED		0x02000000	/* Start in stopped state */
25#define CLONE_NEWUTS		0x04000000	/* New utsname group? */
26#define CLONE_NEWIPC		0x08000000	/* New ipcs */
27#define CLONE_NEWUSER		0x10000000	/* New user namespace */
28#define CLONE_NEWPID		0x20000000	/* New pid namespace */
29#define CLONE_NEWNET		0x40000000	/* New network namespace */
30#define CLONE_IO		0x80000000	/* Clone io context */
31
32/*
33 * Scheduling policies
34 */
35#define SCHED_NORMAL		0
36#define SCHED_FIFO		1
37#define SCHED_RR		2
38#define SCHED_BATCH		3
39/* SCHED_ISO: reserved but not implemented yet */
40#define SCHED_IDLE		5
41/* Can be ORed in to make sure the process is reverted back to SCHED_NORMAL on fork */
42#define SCHED_RESET_ON_FORK     0x40000000
43
44#ifdef __KERNEL__
45
46struct sched_param {
47	int sched_priority;
48};
49
50#include <asm/param.h>	/* for HZ */
51
52#include <linux/capability.h>
53#include <linux/threads.h>
54#include <linux/kernel.h>
55#include <linux/types.h>
56#include <linux/timex.h>
57#include <linux/jiffies.h>
58#include <linux/rbtree.h>
59#include <linux/thread_info.h>
60#include <linux/cpumask.h>
61#include <linux/errno.h>
62#include <linux/nodemask.h>
63#include <linux/mm_types.h>
64
65#include <asm/system.h>
66#include <asm/page.h>
67#include <asm/ptrace.h>
68#include <asm/cputime.h>
69
70#include <linux/smp.h>
71#include <linux/sem.h>
72#include <linux/signal.h>
73#include <linux/path.h>
74#include <linux/compiler.h>
75#include <linux/completion.h>
76#include <linux/pid.h>
77#include <linux/percpu.h>
78#include <linux/topology.h>
79#include <linux/proportions.h>
80#include <linux/seccomp.h>
81#include <linux/rcupdate.h>
82#include <linux/rculist.h>
83#include <linux/rtmutex.h>
84
85#include <linux/time.h>
86#include <linux/param.h>
87#include <linux/resource.h>
88#include <linux/timer.h>
89#include <linux/hrtimer.h>
90#include <linux/task_io_accounting.h>
91#include <linux/kobject.h>
92#include <linux/latencytop.h>
93#include <linux/cred.h>
94
95#include <asm/processor.h>
96
97struct exec_domain;
98struct futex_pi_state;
99struct robust_list_head;
100struct bio;
101struct fs_struct;
102struct bts_context;
103struct perf_counter_context;
104
105/*
106 * List of flags we want to share for kernel threads,
107 * if only because they are not used by them anyway.
108 */
109#define CLONE_KERNEL	(CLONE_FS | CLONE_FILES | CLONE_SIGHAND)
110
111/*
112 * These are the constant used to fake the fixed-point load-average
113 * counting. Some notes:
114 *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
115 *    a load-average precision of 10 bits integer + 11 bits fractional
116 *  - if you want to count load-averages more often, you need more
117 *    precision, or rounding will get you. With 2-second counting freq,
118 *    the EXP_n values would be 1981, 2034 and 2043 if still using only
119 *    11 bit fractions.
120 */
121extern unsigned long avenrun[];		/* Load averages */
122extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
123
124#define FSHIFT		11		/* nr of bits of precision */
125#define FIXED_1		(1<<FSHIFT)	/* 1.0 as fixed-point */
126#define LOAD_FREQ	(5*HZ+1)	/* 5 sec intervals */
127#define EXP_1		1884		/* 1/exp(5sec/1min) as fixed-point */
128#define EXP_5		2014		/* 1/exp(5sec/5min) */
129#define EXP_15		2037		/* 1/exp(5sec/15min) */
130
131#define CALC_LOAD(load,exp,n) \
132	load *= exp; \
133	load += n*(FIXED_1-exp); \
134	load >>= FSHIFT;
135
136extern unsigned long total_forks;
137extern int nr_threads;
138DECLARE_PER_CPU(unsigned long, process_counts);
139extern int nr_processes(void);
140extern unsigned long nr_running(void);
141extern unsigned long nr_uninterruptible(void);
142extern unsigned long nr_iowait(void);
143extern void calc_global_load(void);
144extern u64 cpu_nr_migrations(int cpu);
145
146extern unsigned long get_parent_ip(unsigned long addr);
147
148struct seq_file;
149struct cfs_rq;
150struct task_group;
151#ifdef CONFIG_SCHED_DEBUG
152extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
153extern void proc_sched_set_task(struct task_struct *p);
154extern void
155print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
156#else
157static inline void
158proc_sched_show_task(struct task_struct *p, struct seq_file *m)
159{
160}
161static inline void proc_sched_set_task(struct task_struct *p)
162{
163}
164static inline void
165print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
166{
167}
168#endif
169
170extern unsigned long long time_sync_thresh;
171
172/*
173 * Task state bitmask. NOTE! These bits are also
174 * encoded in fs/proc/array.c: get_task_state().
175 *
176 * We have two separate sets of flags: task->state
177 * is about runnability, while task->exit_state are
178 * about the task exiting. Confusing, but this way
179 * modifying one set can't modify the other one by
180 * mistake.
181 */
182#define TASK_RUNNING		0
183#define TASK_INTERRUPTIBLE	1
184#define TASK_UNINTERRUPTIBLE	2
185#define __TASK_STOPPED		4
186#define __TASK_TRACED		8
187/* in tsk->exit_state */
188#define EXIT_ZOMBIE		16
189#define EXIT_DEAD		32
190/* in tsk->state again */
191#define TASK_DEAD		64
192#define TASK_WAKEKILL		128
193
194/* Convenience macros for the sake of set_task_state */
195#define TASK_KILLABLE		(TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
196#define TASK_STOPPED		(TASK_WAKEKILL | __TASK_STOPPED)
197#define TASK_TRACED		(TASK_WAKEKILL | __TASK_TRACED)
198
199/* Convenience macros for the sake of wake_up */
200#define TASK_NORMAL		(TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
201#define TASK_ALL		(TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
202
203/* get_task_state() */
204#define TASK_REPORT		(TASK_RUNNING | TASK_INTERRUPTIBLE | \
205				 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
206				 __TASK_TRACED)
207
208#define task_is_traced(task)	((task->state & __TASK_TRACED) != 0)
209#define task_is_stopped(task)	((task->state & __TASK_STOPPED) != 0)
210#define task_is_stopped_or_traced(task)	\
211			((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
212#define task_contributes_to_load(task)	\
213				((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
214				 (task->flags & PF_FROZEN) == 0)
215
216#define __set_task_state(tsk, state_value)		\
217	do { (tsk)->state = (state_value); } while (0)
218#define set_task_state(tsk, state_value)		\
219	set_mb((tsk)->state, (state_value))
220
221/*
222 * set_current_state() includes a barrier so that the write of current->state
223 * is correctly serialised wrt the caller's subsequent test of whether to
224 * actually sleep:
225 *
226 *	set_current_state(TASK_UNINTERRUPTIBLE);
227 *	if (do_i_need_to_sleep())
228 *		schedule();
229 *
230 * If the caller does not need such serialisation then use __set_current_state()
231 */
232#define __set_current_state(state_value)			\
233	do { current->state = (state_value); } while (0)
234#define set_current_state(state_value)		\
235	set_mb(current->state, (state_value))
236
237/* Task command name length */
238#define TASK_COMM_LEN 16
239
240#include <linux/spinlock.h>
241
242/*
243 * This serializes "schedule()" and also protects
244 * the run-queue from deletions/modifications (but
245 * _adding_ to the beginning of the run-queue has
246 * a separate lock).
247 */
248extern rwlock_t tasklist_lock;
249extern spinlock_t mmlist_lock;
250
251struct task_struct;
252
253extern void sched_init(void);
254extern void sched_init_smp(void);
255extern asmlinkage void schedule_tail(struct task_struct *prev);
256extern void init_idle(struct task_struct *idle, int cpu);
257extern void init_idle_bootup_task(struct task_struct *idle);
258
259extern int runqueue_is_locked(void);
260extern void task_rq_unlock_wait(struct task_struct *p);
261
262extern cpumask_var_t nohz_cpu_mask;
263#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ)
264extern int select_nohz_load_balancer(int cpu);
265extern int get_nohz_load_balancer(void);
266#else
267static inline int select_nohz_load_balancer(int cpu)
268{
269	return 0;
270}
271#endif
272
273/*
274 * Only dump TASK_* tasks. (0 for all tasks)
275 */
276extern void show_state_filter(unsigned long state_filter);
277
278static inline void show_state(void)
279{
280	show_state_filter(0);
281}
282
283extern void show_regs(struct pt_regs *);
284
285/*
286 * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
287 * task), SP is the stack pointer of the first frame that should be shown in the back
288 * trace (or NULL if the entire call-chain of the task should be shown).
289 */
290extern void show_stack(struct task_struct *task, unsigned long *sp);
291
292void io_schedule(void);
293long io_schedule_timeout(long timeout);
294
295extern void cpu_init (void);
296extern void trap_init(void);
297extern void update_process_times(int user);
298extern void scheduler_tick(void);
299
300extern void sched_show_task(struct task_struct *p);
301
302#ifdef CONFIG_DETECT_SOFTLOCKUP
303extern void softlockup_tick(void);
304extern void touch_softlockup_watchdog(void);
305extern void touch_all_softlockup_watchdogs(void);
306extern int proc_dosoftlockup_thresh(struct ctl_table *table, int write,
307				    struct file *filp, void __user *buffer,
308				    size_t *lenp, loff_t *ppos);
309extern unsigned int  softlockup_panic;
310extern int softlockup_thresh;
311#else
312static inline void softlockup_tick(void)
313{
314}
315static inline void touch_softlockup_watchdog(void)
316{
317}
318static inline void touch_all_softlockup_watchdogs(void)
319{
320}
321#endif
322
323#ifdef CONFIG_DETECT_HUNG_TASK
324extern unsigned int  sysctl_hung_task_panic;
325extern unsigned long sysctl_hung_task_check_count;
326extern unsigned long sysctl_hung_task_timeout_secs;
327extern unsigned long sysctl_hung_task_warnings;
328extern int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
329					 struct file *filp, void __user *buffer,
330					 size_t *lenp, loff_t *ppos);
331#endif
332
333/* Attach to any functions which should be ignored in wchan output. */
334#define __sched		__attribute__((__section__(".sched.text")))
335
336/* Linker adds these: start and end of __sched functions */
337extern char __sched_text_start[], __sched_text_end[];
338
339/* Is this address in the __sched functions? */
340extern int in_sched_functions(unsigned long addr);
341
342#define	MAX_SCHEDULE_TIMEOUT	LONG_MAX
343extern signed long schedule_timeout(signed long timeout);
344extern signed long schedule_timeout_interruptible(signed long timeout);
345extern signed long schedule_timeout_killable(signed long timeout);
346extern signed long schedule_timeout_uninterruptible(signed long timeout);
347asmlinkage void __schedule(void);
348asmlinkage void schedule(void);
349extern int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner);
350
351struct nsproxy;
352struct user_namespace;
353
354/*
355 * Default maximum number of active map areas, this limits the number of vmas
356 * per mm struct. Users can overwrite this number by sysctl but there is a
357 * problem.
358 *
359 * When a program's coredump is generated as ELF format, a section is created
360 * per a vma. In ELF, the number of sections is represented in unsigned short.
361 * This means the number of sections should be smaller than 65535 at coredump.
362 * Because the kernel adds some informative sections to a image of program at
363 * generating coredump, we need some margin. The number of extra sections is
364 * 1-3 now and depends on arch. We use "5" as safe margin, here.
365 */
366#define MAPCOUNT_ELF_CORE_MARGIN	(5)
367#define DEFAULT_MAX_MAP_COUNT	(USHORT_MAX - MAPCOUNT_ELF_CORE_MARGIN)
368
369extern int sysctl_max_map_count;
370
371#include <linux/aio.h>
372
373extern unsigned long
374arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
375		       unsigned long, unsigned long);
376extern unsigned long
377arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
378			  unsigned long len, unsigned long pgoff,
379			  unsigned long flags);
380extern void arch_unmap_area(struct mm_struct *, unsigned long);
381extern void arch_unmap_area_topdown(struct mm_struct *, unsigned long);
382
383#if USE_SPLIT_PTLOCKS
384/*
385 * The mm counters are not protected by its page_table_lock,
386 * so must be incremented atomically.
387 */
388#define set_mm_counter(mm, member, value) atomic_long_set(&(mm)->_##member, value)
389#define get_mm_counter(mm, member) ((unsigned long)atomic_long_read(&(mm)->_##member))
390#define add_mm_counter(mm, member, value) atomic_long_add(value, &(mm)->_##member)
391#define inc_mm_counter(mm, member) atomic_long_inc(&(mm)->_##member)
392#define dec_mm_counter(mm, member) atomic_long_dec(&(mm)->_##member)
393
394#else  /* !USE_SPLIT_PTLOCKS */
395/*
396 * The mm counters are protected by its page_table_lock,
397 * so can be incremented directly.
398 */
399#define set_mm_counter(mm, member, value) (mm)->_##member = (value)
400#define get_mm_counter(mm, member) ((mm)->_##member)
401#define add_mm_counter(mm, member, value) (mm)->_##member += (value)
402#define inc_mm_counter(mm, member) (mm)->_##member++
403#define dec_mm_counter(mm, member) (mm)->_##member--
404
405#endif /* !USE_SPLIT_PTLOCKS */
406
407#define get_mm_rss(mm)					\
408	(get_mm_counter(mm, file_rss) + get_mm_counter(mm, anon_rss))
409#define update_hiwater_rss(mm)	do {			\
410	unsigned long _rss = get_mm_rss(mm);		\
411	if ((mm)->hiwater_rss < _rss)			\
412		(mm)->hiwater_rss = _rss;		\
413} while (0)
414#define update_hiwater_vm(mm)	do {			\
415	if ((mm)->hiwater_vm < (mm)->total_vm)		\
416		(mm)->hiwater_vm = (mm)->total_vm;	\
417} while (0)
418
419static inline unsigned long get_mm_hiwater_rss(struct mm_struct *mm)
420{
421	return max(mm->hiwater_rss, get_mm_rss(mm));
422}
423
424static inline unsigned long get_mm_hiwater_vm(struct mm_struct *mm)
425{
426	return max(mm->hiwater_vm, mm->total_vm);
427}
428
429extern void set_dumpable(struct mm_struct *mm, int value);
430extern int get_dumpable(struct mm_struct *mm);
431
432/* mm flags */
433/* dumpable bits */
434#define MMF_DUMPABLE      0  /* core dump is permitted */
435#define MMF_DUMP_SECURELY 1  /* core file is readable only by root */
436#define MMF_DUMPABLE_BITS 2
437
438/* coredump filter bits */
439#define MMF_DUMP_ANON_PRIVATE	2
440#define MMF_DUMP_ANON_SHARED	3
441#define MMF_DUMP_MAPPED_PRIVATE	4
442#define MMF_DUMP_MAPPED_SHARED	5
443#define MMF_DUMP_ELF_HEADERS	6
444#define MMF_DUMP_HUGETLB_PRIVATE 7
445#define MMF_DUMP_HUGETLB_SHARED  8
446#define MMF_DUMP_FILTER_SHIFT	MMF_DUMPABLE_BITS
447#define MMF_DUMP_FILTER_BITS	7
448#define MMF_DUMP_FILTER_MASK \
449	(((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
450#define MMF_DUMP_FILTER_DEFAULT \
451	((1 << MMF_DUMP_ANON_PRIVATE) |	(1 << MMF_DUMP_ANON_SHARED) |\
452	 (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
453
454#ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
455# define MMF_DUMP_MASK_DEFAULT_ELF	(1 << MMF_DUMP_ELF_HEADERS)
456#else
457# define MMF_DUMP_MASK_DEFAULT_ELF	0
458#endif
459
460struct sighand_struct {
461	atomic_t		count;
462	struct k_sigaction	action[_NSIG];
463	spinlock_t		siglock;
464	wait_queue_head_t	signalfd_wqh;
465};
466
467struct pacct_struct {
468	int			ac_flag;
469	long			ac_exitcode;
470	unsigned long		ac_mem;
471	cputime_t		ac_utime, ac_stime;
472	unsigned long		ac_minflt, ac_majflt;
473};
474
475/**
476 * struct task_cputime - collected CPU time counts
477 * @utime:		time spent in user mode, in &cputime_t units
478 * @stime:		time spent in kernel mode, in &cputime_t units
479 * @sum_exec_runtime:	total time spent on the CPU, in nanoseconds
480 *
481 * This structure groups together three kinds of CPU time that are
482 * tracked for threads and thread groups.  Most things considering
483 * CPU time want to group these counts together and treat all three
484 * of them in parallel.
485 */
486struct task_cputime {
487	cputime_t utime;
488	cputime_t stime;
489	unsigned long long sum_exec_runtime;
490};
491/* Alternate field names when used to cache expirations. */
492#define prof_exp	stime
493#define virt_exp	utime
494#define sched_exp	sum_exec_runtime
495
496#define INIT_CPUTIME	\
497	(struct task_cputime) {					\
498		.utime = cputime_zero,				\
499		.stime = cputime_zero,				\
500		.sum_exec_runtime = 0,				\
501	}
502
503/*
504 * Disable preemption until the scheduler is running.
505 * Reset by start_kernel()->sched_init()->init_idle().
506 *
507 * We include PREEMPT_ACTIVE to avoid cond_resched() from working
508 * before the scheduler is active -- see should_resched().
509 */
510#define INIT_PREEMPT_COUNT	(1 + PREEMPT_ACTIVE)
511
512/**
513 * struct thread_group_cputimer - thread group interval timer counts
514 * @cputime:		thread group interval timers.
515 * @running:		non-zero when there are timers running and
516 * 			@cputime receives updates.
517 * @lock:		lock for fields in this struct.
518 *
519 * This structure contains the version of task_cputime, above, that is
520 * used for thread group CPU timer calculations.
521 */
522struct thread_group_cputimer {
523	struct task_cputime cputime;
524	int running;
525	spinlock_t lock;
526};
527
528/*
529 * NOTE! "signal_struct" does not have it's own
530 * locking, because a shared signal_struct always
531 * implies a shared sighand_struct, so locking
532 * sighand_struct is always a proper superset of
533 * the locking of signal_struct.
534 */
535struct signal_struct {
536	atomic_t		count;
537	atomic_t		live;
538
539	wait_queue_head_t	wait_chldexit;	/* for wait4() */
540
541	/* current thread group signal load-balancing target: */
542	struct task_struct	*curr_target;
543
544	/* shared signal handling: */
545	struct sigpending	shared_pending;
546
547	/* thread group exit support */
548	int			group_exit_code;
549	/* overloaded:
550	 * - notify group_exit_task when ->count is equal to notify_count
551	 * - everyone except group_exit_task is stopped during signal delivery
552	 *   of fatal signals, group_exit_task processes the signal.
553	 */
554	int			notify_count;
555	struct task_struct	*group_exit_task;
556
557	/* thread group stop support, overloads group_exit_code too */
558	int			group_stop_count;
559	unsigned int		flags; /* see SIGNAL_* flags below */
560
561	/* POSIX.1b Interval Timers */
562	struct list_head posix_timers;
563
564	/* ITIMER_REAL timer for the process */
565	struct hrtimer real_timer;
566	struct pid *leader_pid;
567	ktime_t it_real_incr;
568
569	/* ITIMER_PROF and ITIMER_VIRTUAL timers for the process */
570	cputime_t it_prof_expires, it_virt_expires;
571	cputime_t it_prof_incr, it_virt_incr;
572
573	/*
574	 * Thread group totals for process CPU timers.
575	 * See thread_group_cputimer(), et al, for details.
576	 */
577	struct thread_group_cputimer cputimer;
578
579	/* Earliest-expiration cache. */
580	struct task_cputime cputime_expires;
581
582	struct list_head cpu_timers[3];
583
584	struct pid *tty_old_pgrp;
585
586	/* boolean value for session group leader */
587	int leader;
588
589	struct tty_struct *tty; /* NULL if no tty */
590
591	/*
592	 * Cumulative resource counters for dead threads in the group,
593	 * and for reaped dead child processes forked by this group.
594	 * Live threads maintain their own counters and add to these
595	 * in __exit_signal, except for the group leader.
596	 */
597	cputime_t utime, stime, cutime, cstime;
598	cputime_t gtime;
599	cputime_t cgtime;
600	unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
601	unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
602	unsigned long inblock, oublock, cinblock, coublock;
603	struct task_io_accounting ioac;
604
605	/*
606	 * Cumulative ns of schedule CPU time fo dead threads in the
607	 * group, not including a zombie group leader, (This only differs
608	 * from jiffies_to_ns(utime + stime) if sched_clock uses something
609	 * other than jiffies.)
610	 */
611	unsigned long long sum_sched_runtime;
612
613	/*
614	 * We don't bother to synchronize most readers of this at all,
615	 * because there is no reader checking a limit that actually needs
616	 * to get both rlim_cur and rlim_max atomically, and either one
617	 * alone is a single word that can safely be read normally.
618	 * getrlimit/setrlimit use task_lock(current->group_leader) to
619	 * protect this instead of the siglock, because they really
620	 * have no need to disable irqs.
621	 */
622	struct rlimit rlim[RLIM_NLIMITS];
623
624#ifdef CONFIG_BSD_PROCESS_ACCT
625	struct pacct_struct pacct;	/* per-process accounting information */
626#endif
627#ifdef CONFIG_TASKSTATS
628	struct taskstats *stats;
629#endif
630#ifdef CONFIG_AUDIT
631	unsigned audit_tty;
632	struct tty_audit_buf *tty_audit_buf;
633#endif
634};
635
636/* Context switch must be unlocked if interrupts are to be enabled */
637#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
638# define __ARCH_WANT_UNLOCKED_CTXSW
639#endif
640
641/*
642 * Bits in flags field of signal_struct.
643 */
644#define SIGNAL_STOP_STOPPED	0x00000001 /* job control stop in effect */
645#define SIGNAL_STOP_DEQUEUED	0x00000002 /* stop signal dequeued */
646#define SIGNAL_STOP_CONTINUED	0x00000004 /* SIGCONT since WCONTINUED reap */
647#define SIGNAL_GROUP_EXIT	0x00000008 /* group exit in progress */
648/*
649 * Pending notifications to parent.
650 */
651#define SIGNAL_CLD_STOPPED	0x00000010
652#define SIGNAL_CLD_CONTINUED	0x00000020
653#define SIGNAL_CLD_MASK		(SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
654
655#define SIGNAL_UNKILLABLE	0x00000040 /* for init: ignore fatal signals */
656
657/* If true, all threads except ->group_exit_task have pending SIGKILL */
658static inline int signal_group_exit(const struct signal_struct *sig)
659{
660	return	(sig->flags & SIGNAL_GROUP_EXIT) ||
661		(sig->group_exit_task != NULL);
662}
663
664/*
665 * Some day this will be a full-fledged user tracking system..
666 */
667struct user_struct {
668	atomic_t __count;	/* reference count */
669	atomic_t processes;	/* How many processes does this user have? */
670	atomic_t files;		/* How many open files does this user have? */
671	atomic_t sigpending;	/* How many pending signals does this user have? */
672#ifdef CONFIG_INOTIFY_USER
673	atomic_t inotify_watches; /* How many inotify watches does this user have? */
674	atomic_t inotify_devs;	/* How many inotify devs does this user have opened? */
675#endif
676#ifdef CONFIG_EPOLL
677	atomic_t epoll_watches;	/* The number of file descriptors currently watched */
678#endif
679#ifdef CONFIG_POSIX_MQUEUE
680	/* protected by mq_lock	*/
681	unsigned long mq_bytes;	/* How many bytes can be allocated to mqueue? */
682#endif
683	unsigned long locked_shm; /* How many pages of mlocked shm ? */
684
685#ifdef CONFIG_KEYS
686	struct key *uid_keyring;	/* UID specific keyring */
687	struct key *session_keyring;	/* UID's default session keyring */
688#endif
689
690	/* Hash table maintenance information */
691	struct hlist_node uidhash_node;
692	uid_t uid;
693	struct user_namespace *user_ns;
694
695#ifdef CONFIG_USER_SCHED
696	struct task_group *tg;
697#ifdef CONFIG_SYSFS
698	struct kobject kobj;
699	struct delayed_work work;
700#endif
701#endif
702
703#ifdef CONFIG_PERF_COUNTERS
704	atomic_long_t locked_vm;
705#endif
706};
707
708extern int uids_sysfs_init(void);
709
710extern struct user_struct *find_user(uid_t);
711
712extern struct user_struct root_user;
713#define INIT_USER (&root_user)
714
715
716struct backing_dev_info;
717struct reclaim_state;
718
719#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
720struct sched_info {
721	/* cumulative counters */
722	unsigned long pcount;	      /* # of times run on this cpu */
723	unsigned long long run_delay; /* time spent waiting on a runqueue */
724
725	/* timestamps */
726	unsigned long long last_arrival,/* when we last ran on a cpu */
727			   last_queued;	/* when we were last queued to run */
728#ifdef CONFIG_SCHEDSTATS
729	/* BKL stats */
730	unsigned int bkl_count;
731#endif
732};
733#endif /* defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) */
734
735#ifdef CONFIG_TASK_DELAY_ACCT
736struct task_delay_info {
737	spinlock_t	lock;
738	unsigned int	flags;	/* Private per-task flags */
739
740	/* For each stat XXX, add following, aligned appropriately
741	 *
742	 * struct timespec XXX_start, XXX_end;
743	 * u64 XXX_delay;
744	 * u32 XXX_count;
745	 *
746	 * Atomicity of updates to XXX_delay, XXX_count protected by
747	 * single lock above (split into XXX_lock if contention is an issue).
748	 */
749
750	/*
751	 * XXX_count is incremented on every XXX operation, the delay
752	 * associated with the operation is added to XXX_delay.
753	 * XXX_delay contains the accumulated delay time in nanoseconds.
754	 */
755	struct timespec blkio_start, blkio_end;	/* Shared by blkio, swapin */
756	u64 blkio_delay;	/* wait for sync block io completion */
757	u64 swapin_delay;	/* wait for swapin block io completion */
758	u32 blkio_count;	/* total count of the number of sync block */
759				/* io operations performed */
760	u32 swapin_count;	/* total count of the number of swapin block */
761				/* io operations performed */
762
763	struct timespec freepages_start, freepages_end;
764	u64 freepages_delay;	/* wait for memory reclaim */
765	u32 freepages_count;	/* total count of memory reclaim */
766};
767#endif	/* CONFIG_TASK_DELAY_ACCT */
768
769static inline int sched_info_on(void)
770{
771#ifdef CONFIG_SCHEDSTATS
772	return 1;
773#elif defined(CONFIG_TASK_DELAY_ACCT)
774	extern int delayacct_on;
775	return delayacct_on;
776#else
777	return 0;
778#endif
779}
780
781enum cpu_idle_type {
782	CPU_IDLE,
783	CPU_NOT_IDLE,
784	CPU_NEWLY_IDLE,
785	CPU_MAX_IDLE_TYPES
786};
787
788/*
789 * sched-domains (multiprocessor balancing) declarations:
790 */
791
792/*
793 * Increase resolution of nice-level calculations:
794 */
795#define SCHED_LOAD_SHIFT	10
796#define SCHED_LOAD_SCALE	(1L << SCHED_LOAD_SHIFT)
797
798#define SCHED_LOAD_SCALE_FUZZ	SCHED_LOAD_SCALE
799
800#ifdef CONFIG_SMP
801#define SD_LOAD_BALANCE		1	/* Do load balancing on this domain. */
802#define SD_BALANCE_NEWIDLE	2	/* Balance when about to become idle */
803#define SD_BALANCE_EXEC		4	/* Balance on exec */
804#define SD_BALANCE_FORK		8	/* Balance on fork, clone */
805#define SD_WAKE_IDLE		16	/* Wake to idle CPU on task wakeup */
806#define SD_WAKE_AFFINE		32	/* Wake task to waking CPU */
807#define SD_WAKE_BALANCE		64	/* Perform balancing at task wakeup */
808#define SD_SHARE_CPUPOWER	128	/* Domain members share cpu power */
809#define SD_POWERSAVINGS_BALANCE	256	/* Balance for power savings */
810#define SD_SHARE_PKG_RESOURCES	512	/* Domain members share cpu pkg resources */
811#define SD_SERIALIZE		1024	/* Only a single load balancing instance */
812#define SD_WAKE_IDLE_FAR	2048	/* Gain latency sacrificing cache hit */
813
814enum powersavings_balance_level {
815	POWERSAVINGS_BALANCE_NONE = 0,  /* No power saving load balance */
816	POWERSAVINGS_BALANCE_BASIC,	/* Fill one thread/core/package
817					 * first for long running threads
818					 */
819	POWERSAVINGS_BALANCE_WAKEUP,	/* Also bias task wakeups to semi-idle
820					 * cpu package for power savings
821					 */
822	MAX_POWERSAVINGS_BALANCE_LEVELS
823};
824
825extern int sched_mc_power_savings, sched_smt_power_savings;
826
827static inline int sd_balance_for_mc_power(void)
828{
829	if (sched_smt_power_savings)
830		return SD_POWERSAVINGS_BALANCE;
831
832	return 0;
833}
834
835static inline int sd_balance_for_package_power(void)
836{
837	if (sched_mc_power_savings | sched_smt_power_savings)
838		return SD_POWERSAVINGS_BALANCE;
839
840	return 0;
841}
842
843/*
844 * Optimise SD flags for power savings:
845 * SD_BALANCE_NEWIDLE helps agressive task consolidation and power savings.
846 * Keep default SD flags if sched_{smt,mc}_power_saving=0
847 */
848
849static inline int sd_power_saving_flags(void)
850{
851	if (sched_mc_power_savings | sched_smt_power_savings)
852		return SD_BALANCE_NEWIDLE;
853
854	return 0;
855}
856
857struct sched_group {
858	struct sched_group *next;	/* Must be a circular list */
859
860	/*
861	 * CPU power of this group, SCHED_LOAD_SCALE being max power for a
862	 * single CPU. This is read only (except for setup, hotplug CPU).
863	 * Note : Never change cpu_power without recompute its reciprocal
864	 */
865	unsigned int __cpu_power;
866	/*
867	 * reciprocal value of cpu_power to avoid expensive divides
868	 * (see include/linux/reciprocal_div.h)
869	 */
870	u32 reciprocal_cpu_power;
871
872	/*
873	 * The CPUs this group covers.
874	 *
875	 * NOTE: this field is variable length. (Allocated dynamically
876	 * by attaching extra space to the end of the structure,
877	 * depending on how many CPUs the kernel has booted up with)
878	 *
879	 * It is also be embedded into static data structures at build
880	 * time. (See 'struct static_sched_group' in kernel/sched.c)
881	 */
882	unsigned long cpumask[0];
883};
884
885static inline struct cpumask *sched_group_cpus(struct sched_group *sg)
886{
887	return to_cpumask(sg->cpumask);
888}
889
890enum sched_domain_level {
891	SD_LV_NONE = 0,
892	SD_LV_SIBLING,
893	SD_LV_MC,
894	SD_LV_CPU,
895	SD_LV_NODE,
896	SD_LV_ALLNODES,
897	SD_LV_MAX
898};
899
900struct sched_domain_attr {
901	int relax_domain_level;
902};
903
904#define SD_ATTR_INIT	(struct sched_domain_attr) {	\
905	.relax_domain_level = -1,			\
906}
907
908struct sched_domain {
909	/* These fields must be setup */
910	struct sched_domain *parent;	/* top domain must be null terminated */
911	struct sched_domain *child;	/* bottom domain must be null terminated */
912	struct sched_group *groups;	/* the balancing groups of the domain */
913	unsigned long min_interval;	/* Minimum balance interval ms */
914	unsigned long max_interval;	/* Maximum balance interval ms */
915	unsigned int busy_factor;	/* less balancing by factor if busy */
916	unsigned int imbalance_pct;	/* No balance until over watermark */
917	unsigned int cache_nice_tries;	/* Leave cache hot tasks for # tries */
918	unsigned int busy_idx;
919	unsigned int idle_idx;
920	unsigned int newidle_idx;
921	unsigned int wake_idx;
922	unsigned int forkexec_idx;
923	int flags;			/* See SD_* */
924	enum sched_domain_level level;
925
926	/* Runtime fields. */
927	unsigned long last_balance;	/* init to jiffies. units in jiffies */
928	unsigned int balance_interval;	/* initialise to 1. units in ms. */
929	unsigned int nr_balance_failed; /* initialise to 0 */
930
931	u64 last_update;
932
933#ifdef CONFIG_SCHEDSTATS
934	/* load_balance() stats */
935	unsigned int lb_count[CPU_MAX_IDLE_TYPES];
936	unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
937	unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
938	unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
939	unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
940	unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
941	unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
942	unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
943
944	/* Active load balancing */
945	unsigned int alb_count;
946	unsigned int alb_failed;
947	unsigned int alb_pushed;
948
949	/* SD_BALANCE_EXEC stats */
950	unsigned int sbe_count;
951	unsigned int sbe_balanced;
952	unsigned int sbe_pushed;
953
954	/* SD_BALANCE_FORK stats */
955	unsigned int sbf_count;
956	unsigned int sbf_balanced;
957	unsigned int sbf_pushed;
958
959	/* try_to_wake_up() stats */
960	unsigned int ttwu_wake_remote;
961	unsigned int ttwu_move_affine;
962	unsigned int ttwu_move_balance;
963#endif
964#ifdef CONFIG_SCHED_DEBUG
965	char *name;
966#endif
967
968	/*
969	 * Span of all CPUs in this domain.
970	 *
971	 * NOTE: this field is variable length. (Allocated dynamically
972	 * by attaching extra space to the end of the structure,
973	 * depending on how many CPUs the kernel has booted up with)
974	 *
975	 * It is also be embedded into static data structures at build
976	 * time. (See 'struct static_sched_domain' in kernel/sched.c)
977	 */
978	unsigned long span[0];
979};
980
981static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
982{
983	return to_cpumask(sd->span);
984}
985
986extern void partition_sched_domains(int ndoms_new, struct cpumask *doms_new,
987				    struct sched_domain_attr *dattr_new);
988
989/* Test a flag in parent sched domain */
990static inline int test_sd_parent(struct sched_domain *sd, int flag)
991{
992	if (sd->parent && (sd->parent->flags & flag))
993		return 1;
994
995	return 0;
996}
997
998#else /* CONFIG_SMP */
999
1000struct sched_domain_attr;
1001
1002static inline void
1003partition_sched_domains(int ndoms_new, struct cpumask *doms_new,
1004			struct sched_domain_attr *dattr_new)
1005{
1006}
1007#endif	/* !CONFIG_SMP */
1008
1009struct io_context;			/* See blkdev.h */
1010
1011
1012#ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
1013extern void prefetch_stack(struct task_struct *t);
1014#else
1015static inline void prefetch_stack(struct task_struct *t) { }
1016#endif
1017
1018struct audit_context;		/* See audit.c */
1019struct mempolicy;
1020struct pipe_inode_info;
1021struct uts_namespace;
1022
1023struct rq;
1024struct sched_domain;
1025
1026struct sched_class {
1027	const struct sched_class *next;
1028
1029	void (*enqueue_task) (struct rq *rq, struct task_struct *p, int wakeup);
1030	void (*dequeue_task) (struct rq *rq, struct task_struct *p, int sleep);
1031	void (*yield_task) (struct rq *rq);
1032
1033	void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int sync);
1034
1035	struct task_struct * (*pick_next_task) (struct rq *rq);
1036	void (*put_prev_task) (struct rq *rq, struct task_struct *p);
1037
1038#ifdef CONFIG_SMP
1039	int  (*select_task_rq)(struct task_struct *p, int sync);
1040
1041	unsigned long (*load_balance) (struct rq *this_rq, int this_cpu,
1042			struct rq *busiest, unsigned long max_load_move,
1043			struct sched_domain *sd, enum cpu_idle_type idle,
1044			int *all_pinned, int *this_best_prio);
1045
1046	int (*move_one_task) (struct rq *this_rq, int this_cpu,
1047			      struct rq *busiest, struct sched_domain *sd,
1048			      enum cpu_idle_type idle);
1049	void (*pre_schedule) (struct rq *this_rq, struct task_struct *task);
1050	int (*needs_post_schedule) (struct rq *this_rq);
1051	void (*post_schedule) (struct rq *this_rq);
1052	void (*task_wake_up) (struct rq *this_rq, struct task_struct *task);
1053
1054	void (*set_cpus_allowed)(struct task_struct *p,
1055				 const struct cpumask *newmask);
1056
1057	void (*rq_online)(struct rq *rq);
1058	void (*rq_offline)(struct rq *rq);
1059#endif
1060
1061	void (*set_curr_task) (struct rq *rq);
1062	void (*task_tick) (struct rq *rq, struct task_struct *p, int queued);
1063	void (*task_new) (struct rq *rq, struct task_struct *p);
1064
1065	void (*switched_from) (struct rq *this_rq, struct task_struct *task,
1066			       int running);
1067	void (*switched_to) (struct rq *this_rq, struct task_struct *task,
1068			     int running);
1069	void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
1070			     int oldprio, int running);
1071
1072#ifdef CONFIG_FAIR_GROUP_SCHED
1073	void (*moved_group) (struct task_struct *p);
1074#endif
1075};
1076
1077struct load_weight {
1078	unsigned long weight, inv_weight;
1079};
1080
1081/*
1082 * CFS stats for a schedulable entity (task, task-group etc)
1083 *
1084 * Current field usage histogram:
1085 *
1086 *     4 se->block_start
1087 *     4 se->run_node
1088 *     4 se->sleep_start
1089 *     6 se->load.weight
1090 */
1091struct sched_entity {
1092	struct load_weight	load;		/* for load-balancing */
1093	struct rb_node		run_node;
1094	struct list_head	group_node;
1095	unsigned int		on_rq;
1096
1097	u64			exec_start;
1098	u64			sum_exec_runtime;
1099	u64			vruntime;
1100	u64			prev_sum_exec_runtime;
1101
1102	u64			last_wakeup;
1103	u64			avg_overlap;
1104
1105	u64			nr_migrations;
1106
1107	u64			start_runtime;
1108	u64			avg_wakeup;
1109
1110#ifdef CONFIG_SCHEDSTATS
1111	u64			wait_start;
1112	u64			wait_max;
1113	u64			wait_count;
1114	u64			wait_sum;
1115
1116	u64			sleep_start;
1117	u64			sleep_max;
1118	s64			sum_sleep_runtime;
1119
1120	u64			block_start;
1121	u64			block_max;
1122	u64			exec_max;
1123	u64			slice_max;
1124
1125	u64			nr_migrations_cold;
1126	u64			nr_failed_migrations_affine;
1127	u64			nr_failed_migrations_running;
1128	u64			nr_failed_migrations_hot;
1129	u64			nr_forced_migrations;
1130	u64			nr_forced2_migrations;
1131
1132	u64			nr_wakeups;
1133	u64			nr_wakeups_sync;
1134	u64			nr_wakeups_migrate;
1135	u64			nr_wakeups_local;
1136	u64			nr_wakeups_remote;
1137	u64			nr_wakeups_affine;
1138	u64			nr_wakeups_affine_attempts;
1139	u64			nr_wakeups_passive;
1140	u64			nr_wakeups_idle;
1141#endif
1142
1143#ifdef CONFIG_FAIR_GROUP_SCHED
1144	struct sched_entity	*parent;
1145	/* rq on which this entity is (to be) queued: */
1146	struct cfs_rq		*cfs_rq;
1147	/* rq "owned" by this entity/group: */
1148	struct cfs_rq		*my_q;
1149#endif
1150};
1151
1152struct sched_rt_entity {
1153	struct list_head run_list;
1154	unsigned long timeout;
1155	unsigned int time_slice;
1156	int nr_cpus_allowed;
1157
1158	struct sched_rt_entity *back;
1159#ifdef CONFIG_RT_GROUP_SCHED
1160	struct sched_rt_entity	*parent;
1161	/* rq on which this entity is (to be) queued: */
1162	struct rt_rq		*rt_rq;
1163	/* rq "owned" by this entity/group: */
1164	struct rt_rq		*my_q;
1165#endif
1166};
1167
1168struct task_struct {
1169	volatile long state;	/* -1 unrunnable, 0 runnable, >0 stopped */
1170	void *stack;
1171	atomic_t usage;
1172	unsigned int flags;	/* per process flags, defined below */
1173	unsigned int ptrace;
1174
1175	int lock_depth;		/* BKL lock depth */
1176
1177#ifdef CONFIG_SMP
1178#ifdef __ARCH_WANT_UNLOCKED_CTXSW
1179	int oncpu;
1180#endif
1181#endif
1182
1183	int prio, static_prio, normal_prio;
1184	unsigned int rt_priority;
1185	const struct sched_class *sched_class;
1186	struct sched_entity se;
1187	struct sched_rt_entity rt;
1188
1189#ifdef CONFIG_PREEMPT_NOTIFIERS
1190	/* list of struct preempt_notifier: */
1191	struct hlist_head preempt_notifiers;
1192#endif
1193
1194	/*
1195	 * fpu_counter contains the number of consecutive context switches
1196	 * that the FPU is used. If this is over a threshold, the lazy fpu
1197	 * saving becomes unlazy to save the trap. This is an unsigned char
1198	 * so that after 256 times the counter wraps and the behavior turns
1199	 * lazy again; this to deal with bursty apps that only use FPU for
1200	 * a short time
1201	 */
1202	unsigned char fpu_counter;
1203#ifdef CONFIG_BLK_DEV_IO_TRACE
1204	unsigned int btrace_seq;
1205#endif
1206
1207	unsigned int policy;
1208	cpumask_t cpus_allowed;
1209
1210#ifdef CONFIG_PREEMPT_RCU
1211	int rcu_read_lock_nesting;
1212	int rcu_flipctr_idx;
1213#endif /* #ifdef CONFIG_PREEMPT_RCU */
1214
1215#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
1216	struct sched_info sched_info;
1217#endif
1218
1219	struct list_head tasks;
1220	struct plist_node pushable_tasks;
1221
1222	struct mm_struct *mm, *active_mm;
1223
1224/* task state */
1225	struct linux_binfmt *binfmt;
1226	int exit_state;
1227	int exit_code, exit_signal;
1228	int pdeath_signal;  /*  The signal sent when the parent dies  */
1229	/* ??? */
1230	unsigned int personality;
1231	unsigned did_exec:1;
1232	unsigned in_execve:1;	/* Tell the LSMs that the process is doing an
1233				 * execve */
1234
1235	/* Revert to default priority/policy when forking */
1236	unsigned sched_reset_on_fork:1;
1237
1238	pid_t pid;
1239	pid_t tgid;
1240
1241	/* Canary value for the -fstack-protector gcc feature */
1242	unsigned long stack_canary;
1243
1244	/*
1245	 * pointers to (original) parent process, youngest child, younger sibling,
1246	 * older sibling, respectively.  (p->father can be replaced with
1247	 * p->real_parent->pid)
1248	 */
1249	struct task_struct *real_parent; /* real parent process */
1250	struct task_struct *parent; /* recipient of SIGCHLD, wait4() reports */
1251	/*
1252	 * children/sibling forms the list of my natural children
1253	 */
1254	struct list_head children;	/* list of my children */
1255	struct list_head sibling;	/* linkage in my parent's children list */
1256	struct task_struct *group_leader;	/* threadgroup leader */
1257
1258	/*
1259	 * ptraced is the list of tasks this task is using ptrace on.
1260	 * This includes both natural children and PTRACE_ATTACH targets.
1261	 * p->ptrace_entry is p's link on the p->parent->ptraced list.
1262	 */
1263	struct list_head ptraced;
1264	struct list_head ptrace_entry;
1265
1266	/*
1267	 * This is the tracer handle for the ptrace BTS extension.
1268	 * This field actually belongs to the ptracer task.
1269	 */
1270	struct bts_context *bts;
1271
1272	/* PID/PID hash table linkage. */
1273	struct pid_link pids[PIDTYPE_MAX];
1274	struct list_head thread_group;
1275
1276	struct completion *vfork_done;		/* for vfork() */
1277	int __user *set_child_tid;		/* CLONE_CHILD_SETTID */
1278	int __user *clear_child_tid;		/* CLONE_CHILD_CLEARTID */
1279
1280	cputime_t utime, stime, utimescaled, stimescaled;
1281	cputime_t gtime;
1282	cputime_t prev_utime, prev_stime;
1283	unsigned long nvcsw, nivcsw; /* context switch counts */
1284	struct timespec start_time; 		/* monotonic time */
1285	struct timespec real_start_time;	/* boot based time */
1286/* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1287	unsigned long min_flt, maj_flt;
1288
1289	struct task_cputime cputime_expires;
1290	struct list_head cpu_timers[3];
1291
1292/* process credentials */
1293	const struct cred *real_cred;	/* objective and real subjective task
1294					 * credentials (COW) */
1295	const struct cred *cred;	/* effective (overridable) subjective task
1296					 * credentials (COW) */
1297	struct mutex cred_guard_mutex;	/* guard against foreign influences on
1298					 * credential calculations
1299					 * (notably. ptrace) */
1300
1301	char comm[TASK_COMM_LEN]; /* executable name excluding path
1302				     - access with [gs]et_task_comm (which lock
1303				       it with task_lock())
1304				     - initialized normally by flush_old_exec */
1305/* file system info */
1306	int link_count, total_link_count;
1307#ifdef CONFIG_SYSVIPC
1308/* ipc stuff */
1309	struct sysv_sem sysvsem;
1310#endif
1311#ifdef CONFIG_DETECT_HUNG_TASK
1312/* hung task detection */
1313	unsigned long last_switch_count;
1314#endif
1315/* CPU-specific state of this task */
1316	struct thread_struct thread;
1317/* filesystem information */
1318	struct fs_struct *fs;
1319/* open file information */
1320	struct files_struct *files;
1321/* namespaces */
1322	struct nsproxy *nsproxy;
1323/* signal handlers */
1324	struct signal_struct *signal;
1325	struct sighand_struct *sighand;
1326
1327	sigset_t blocked, real_blocked;
1328	sigset_t saved_sigmask;	/* restored if set_restore_sigmask() was used */
1329	struct sigpending pending;
1330
1331	unsigned long sas_ss_sp;
1332	size_t sas_ss_size;
1333	int (*notifier)(void *priv);
1334	void *notifier_data;
1335	sigset_t *notifier_mask;
1336	struct audit_context *audit_context;
1337#ifdef CONFIG_AUDITSYSCALL
1338	uid_t loginuid;
1339	unsigned int sessionid;
1340#endif
1341	seccomp_t seccomp;
1342
1343/* Thread group tracking */
1344   	u32 parent_exec_id;
1345   	u32 self_exec_id;
1346/* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1347 * mempolicy */
1348	spinlock_t alloc_lock;
1349
1350#ifdef CONFIG_GENERIC_HARDIRQS
1351	/* IRQ handler threads */
1352	struct irqaction *irqaction;
1353#endif
1354
1355	/* Protection of the PI data structures: */
1356	spinlock_t pi_lock;
1357
1358#ifdef CONFIG_RT_MUTEXES
1359	/* PI waiters blocked on a rt_mutex held by this task */
1360	struct plist_head pi_waiters;
1361	/* Deadlock detection and priority inheritance handling */
1362	struct rt_mutex_waiter *pi_blocked_on;
1363#endif
1364
1365#ifdef CONFIG_DEBUG_MUTEXES
1366	/* mutex deadlock detection */
1367	struct mutex_waiter *blocked_on;
1368#endif
1369#ifdef CONFIG_TRACE_IRQFLAGS
1370	unsigned int irq_events;
1371	int hardirqs_enabled;
1372	unsigned long hardirq_enable_ip;
1373	unsigned int hardirq_enable_event;
1374	unsigned long hardirq_disable_ip;
1375	unsigned int hardirq_disable_event;
1376	int softirqs_enabled;
1377	unsigned long softirq_disable_ip;
1378	unsigned int softirq_disable_event;
1379	unsigned long softirq_enable_ip;
1380	unsigned int softirq_enable_event;
1381	int hardirq_context;
1382	int softirq_context;
1383#endif
1384#ifdef CONFIG_LOCKDEP
1385# define MAX_LOCK_DEPTH 48UL
1386	u64 curr_chain_key;
1387	int lockdep_depth;
1388	unsigned int lockdep_recursion;
1389	struct held_lock held_locks[MAX_LOCK_DEPTH];
1390	gfp_t lockdep_reclaim_gfp;
1391#endif
1392
1393/* journalling filesystem info */
1394	void *journal_info;
1395
1396/* stacked block device info */
1397	struct bio *bio_list, **bio_tail;
1398
1399/* VM state */
1400	struct reclaim_state *reclaim_state;
1401
1402	struct backing_dev_info *backing_dev_info;
1403
1404	struct io_context *io_context;
1405
1406	unsigned long ptrace_message;
1407	siginfo_t *last_siginfo; /* For ptrace use.  */
1408	struct task_io_accounting ioac;
1409#if defined(CONFIG_TASK_XACCT)
1410	u64 acct_rss_mem1;	/* accumulated rss usage */
1411	u64 acct_vm_mem1;	/* accumulated virtual memory usage */
1412	cputime_t acct_timexpd;	/* stime + utime since last update */
1413#endif
1414#ifdef CONFIG_CPUSETS
1415	nodemask_t mems_allowed;	/* Protected by alloc_lock */
1416	int cpuset_mem_spread_rotor;
1417#endif
1418#ifdef CONFIG_CGROUPS
1419	/* Control Group info protected by css_set_lock */
1420	struct css_set *cgroups;
1421	/* cg_list protected by css_set_lock and tsk->alloc_lock */
1422	struct list_head cg_list;
1423#endif
1424#ifdef CONFIG_FUTEX
1425	struct robust_list_head __user *robust_list;
1426#ifdef CONFIG_COMPAT
1427	struct compat_robust_list_head __user *compat_robust_list;
1428#endif
1429	struct list_head pi_state_list;
1430	struct futex_pi_state *pi_state_cache;
1431#endif
1432#ifdef CONFIG_PERF_COUNTERS
1433	struct perf_counter_context *perf_counter_ctxp;
1434	struct mutex perf_counter_mutex;
1435	struct list_head perf_counter_list;
1436#endif
1437#ifdef CONFIG_NUMA
1438	struct mempolicy *mempolicy;	/* Protected by alloc_lock */
1439	short il_next;
1440#endif
1441	atomic_t fs_excl;	/* holding fs exclusive resources */
1442	struct rcu_head rcu;
1443
1444	/*
1445	 * cache last used pipe for splice
1446	 */
1447	struct pipe_inode_info *splice_pipe;
1448#ifdef	CONFIG_TASK_DELAY_ACCT
1449	struct task_delay_info *delays;
1450#endif
1451#ifdef CONFIG_FAULT_INJECTION
1452	int make_it_fail;
1453#endif
1454	struct prop_local_single dirties;
1455#ifdef CONFIG_LATENCYTOP
1456	int latency_record_count;
1457	struct latency_record latency_record[LT_SAVECOUNT];
1458#endif
1459	/*
1460	 * time slack values; these are used to round up poll() and
1461	 * select() etc timeout values. These are in nanoseconds.
1462	 */
1463	unsigned long timer_slack_ns;
1464	unsigned long default_timer_slack_ns;
1465
1466	struct list_head	*scm_work_list;
1467#ifdef CONFIG_FUNCTION_GRAPH_TRACER
1468	/* Index of current stored adress in ret_stack */
1469	int curr_ret_stack;
1470	/* Stack of return addresses for return function tracing */
1471	struct ftrace_ret_stack	*ret_stack;
1472	/* time stamp for last schedule */
1473	unsigned long long ftrace_timestamp;
1474	/*
1475	 * Number of functions that haven't been traced
1476	 * because of depth overrun.
1477	 */
1478	atomic_t trace_overrun;
1479	/* Pause for the tracing */
1480	atomic_t tracing_graph_pause;
1481#endif
1482#ifdef CONFIG_TRACING
1483	/* state flags for use by tracers */
1484	unsigned long trace;
1485	/* bitmask of trace recursion */
1486	unsigned long trace_recursion;
1487#endif /* CONFIG_TRACING */
1488};
1489
1490/* Future-safe accessor for struct task_struct's cpus_allowed. */
1491#define tsk_cpumask(tsk) (&(tsk)->cpus_allowed)
1492
1493/*
1494 * Priority of a process goes from 0..MAX_PRIO-1, valid RT
1495 * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
1496 * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority
1497 * values are inverted: lower p->prio value means higher priority.
1498 *
1499 * The MAX_USER_RT_PRIO value allows the actual maximum
1500 * RT priority to be separate from the value exported to
1501 * user-space.  This allows kernel threads to set their
1502 * priority to a value higher than any user task. Note:
1503 * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
1504 */
1505
1506#define MAX_USER_RT_PRIO	100
1507#define MAX_RT_PRIO		MAX_USER_RT_PRIO
1508
1509#define MAX_PRIO		(MAX_RT_PRIO + 40)
1510#define DEFAULT_PRIO		(MAX_RT_PRIO + 20)
1511
1512static inline int rt_prio(int prio)
1513{
1514	if (unlikely(prio < MAX_RT_PRIO))
1515		return 1;
1516	return 0;
1517}
1518
1519static inline int rt_task(struct task_struct *p)
1520{
1521	return rt_prio(p->prio);
1522}
1523
1524static inline struct pid *task_pid(struct task_struct *task)
1525{
1526	return task->pids[PIDTYPE_PID].pid;
1527}
1528
1529static inline struct pid *task_tgid(struct task_struct *task)
1530{
1531	return task->group_leader->pids[PIDTYPE_PID].pid;
1532}
1533
1534/*
1535 * Without tasklist or rcu lock it is not safe to dereference
1536 * the result of task_pgrp/task_session even if task == current,
1537 * we can race with another thread doing sys_setsid/sys_setpgid.
1538 */
1539static inline struct pid *task_pgrp(struct task_struct *task)
1540{
1541	return task->group_leader->pids[PIDTYPE_PGID].pid;
1542}
1543
1544static inline struct pid *task_session(struct task_struct *task)
1545{
1546	return task->group_leader->pids[PIDTYPE_SID].pid;
1547}
1548
1549struct pid_namespace;
1550
1551/*
1552 * the helpers to get the task's different pids as they are seen
1553 * from various namespaces
1554 *
1555 * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1556 * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1557 *                     current.
1558 * task_xid_nr_ns()  : id seen from the ns specified;
1559 *
1560 * set_task_vxid()   : assigns a virtual id to a task;
1561 *
1562 * see also pid_nr() etc in include/linux/pid.h
1563 */
1564pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
1565			struct pid_namespace *ns);
1566
1567static inline pid_t task_pid_nr(struct task_struct *tsk)
1568{
1569	return tsk->pid;
1570}
1571
1572static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
1573					struct pid_namespace *ns)
1574{
1575	return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1576}
1577
1578static inline pid_t task_pid_vnr(struct task_struct *tsk)
1579{
1580	return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1581}
1582
1583
1584static inline pid_t task_tgid_nr(struct task_struct *tsk)
1585{
1586	return tsk->tgid;
1587}
1588
1589pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1590
1591static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1592{
1593	return pid_vnr(task_tgid(tsk));
1594}
1595
1596
1597static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
1598					struct pid_namespace *ns)
1599{
1600	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1601}
1602
1603static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1604{
1605	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1606}
1607
1608
1609static inline pid_t task_session_nr_ns(struct task_struct *tsk,
1610					struct pid_namespace *ns)
1611{
1612	return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1613}
1614
1615static inline pid_t task_session_vnr(struct task_struct *tsk)
1616{
1617	return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1618}
1619
1620/* obsolete, do not use */
1621static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1622{
1623	return task_pgrp_nr_ns(tsk, &init_pid_ns);
1624}
1625
1626/**
1627 * pid_alive - check that a task structure is not stale
1628 * @p: Task structure to be checked.
1629 *
1630 * Test if a process is not yet dead (at most zombie state)
1631 * If pid_alive fails, then pointers within the task structure
1632 * can be stale and must not be dereferenced.
1633 */
1634static inline int pid_alive(struct task_struct *p)
1635{
1636	return p->pids[PIDTYPE_PID].pid != NULL;
1637}
1638
1639/**
1640 * is_global_init - check if a task structure is init
1641 * @tsk: Task structure to be checked.
1642 *
1643 * Check if a task structure is the first user space task the kernel created.
1644 */
1645static inline int is_global_init(struct task_struct *tsk)
1646{
1647	return tsk->pid == 1;
1648}
1649
1650/*
1651 * is_container_init:
1652 * check whether in the task is init in its own pid namespace.
1653 */
1654extern int is_container_init(struct task_struct *tsk);
1655
1656extern struct pid *cad_pid;
1657
1658extern void free_task(struct task_struct *tsk);
1659#define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
1660
1661extern void __put_task_struct(struct task_struct *t);
1662
1663static inline void put_task_struct(struct task_struct *t)
1664{
1665	if (atomic_dec_and_test(&t->usage))
1666		__put_task_struct(t);
1667}
1668
1669extern cputime_t task_utime(struct task_struct *p);
1670extern cputime_t task_stime(struct task_struct *p);
1671extern cputime_t task_gtime(struct task_struct *p);
1672
1673/*
1674 * Per process flags
1675 */
1676#define PF_ALIGNWARN	0x00000001	/* Print alignment warning msgs */
1677					/* Not implemented yet, only for 486*/
1678#define PF_STARTING	0x00000002	/* being created */
1679#define PF_EXITING	0x00000004	/* getting shut down */
1680#define PF_EXITPIDONE	0x00000008	/* pi exit done on shut down */
1681#define PF_VCPU		0x00000010	/* I'm a virtual CPU */
1682#define PF_FORKNOEXEC	0x00000040	/* forked but didn't exec */
1683#define PF_SUPERPRIV	0x00000100	/* used super-user privileges */
1684#define PF_DUMPCORE	0x00000200	/* dumped core */
1685#define PF_SIGNALED	0x00000400	/* killed by a signal */
1686#define PF_MEMALLOC	0x00000800	/* Allocating memory */
1687#define PF_FLUSHER	0x00001000	/* responsible for disk writeback */
1688#define PF_USED_MATH	0x00002000	/* if unset the fpu must be initialized before use */
1689#define PF_NOFREEZE	0x00008000	/* this thread should not be frozen */
1690#define PF_FROZEN	0x00010000	/* frozen for system suspend */
1691#define PF_FSTRANS	0x00020000	/* inside a filesystem transaction */
1692#define PF_KSWAPD	0x00040000	/* I am kswapd */
1693#define PF_SWAPOFF	0x00080000	/* I am in swapoff */
1694#define PF_LESS_THROTTLE 0x00100000	/* Throttle me less: I clean memory */
1695#define PF_KTHREAD	0x00200000	/* I am a kernel thread */
1696#define PF_RANDOMIZE	0x00400000	/* randomize virtual address space */
1697#define PF_SWAPWRITE	0x00800000	/* Allowed to write to swap */
1698#define PF_SPREAD_PAGE	0x01000000	/* Spread page cache over cpuset */
1699#define PF_SPREAD_SLAB	0x02000000	/* Spread some slab caches over cpuset */
1700#define PF_THREAD_BOUND	0x04000000	/* Thread bound to specific cpu */
1701#define PF_MEMPOLICY	0x10000000	/* Non-default NUMA mempolicy */
1702#define PF_MUTEX_TESTER	0x20000000	/* Thread belongs to the rt mutex tester */
1703#define PF_FREEZER_SKIP	0x40000000	/* Freezer should not count it as freezeable */
1704#define PF_FREEZER_NOSIG 0x80000000	/* Freezer won't send signals to it */
1705
1706/*
1707 * Only the _current_ task can read/write to tsk->flags, but other
1708 * tasks can access tsk->flags in readonly mode for example
1709 * with tsk_used_math (like during threaded core dumping).
1710 * There is however an exception to this rule during ptrace
1711 * or during fork: the ptracer task is allowed to write to the
1712 * child->flags of its traced child (same goes for fork, the parent
1713 * can write to the child->flags), because we're guaranteed the
1714 * child is not running and in turn not changing child->flags
1715 * at the same time the parent does it.
1716 */
1717#define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1718#define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1719#define clear_used_math() clear_stopped_child_used_math(current)
1720#define set_used_math() set_stopped_child_used_math(current)
1721#define conditional_stopped_child_used_math(condition, child) \
1722	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1723#define conditional_used_math(condition) \
1724	conditional_stopped_child_used_math(condition, current)
1725#define copy_to_stopped_child_used_math(child) \
1726	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1727/* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1728#define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1729#define used_math() tsk_used_math(current)
1730
1731#ifdef CONFIG_SMP
1732extern int set_cpus_allowed_ptr(struct task_struct *p,
1733				const struct cpumask *new_mask);
1734#else
1735static inline int set_cpus_allowed_ptr(struct task_struct *p,
1736				       const struct cpumask *new_mask)
1737{
1738	if (!cpumask_test_cpu(0, new_mask))
1739		return -EINVAL;
1740	return 0;
1741}
1742#endif
1743static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
1744{
1745	return set_cpus_allowed_ptr(p, &new_mask);
1746}
1747
1748/*
1749 * Architectures can set this to 1 if they have specified
1750 * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
1751 * but then during bootup it turns out that sched_clock()
1752 * is reliable after all:
1753 */
1754#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
1755extern int sched_clock_stable;
1756#endif
1757
1758extern unsigned long long sched_clock(void);
1759
1760extern void sched_clock_init(void);
1761extern u64 sched_clock_cpu(int cpu);
1762
1763#ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
1764static inline void sched_clock_tick(void)
1765{
1766}
1767
1768static inline void sched_clock_idle_sleep_event(void)
1769{
1770}
1771
1772static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
1773{
1774}
1775#else
1776extern void sched_clock_tick(void);
1777extern void sched_clock_idle_sleep_event(void);
1778extern void sched_clock_idle_wakeup_event(u64 delta_ns);
1779#endif
1780
1781/*
1782 * For kernel-internal use: high-speed (but slightly incorrect) per-cpu
1783 * clock constructed from sched_clock():
1784 */
1785extern unsigned long long cpu_clock(int cpu);
1786
1787extern unsigned long long
1788task_sched_runtime(struct task_struct *task);
1789extern unsigned long long thread_group_sched_runtime(struct task_struct *task);
1790
1791/* sched_exec is called by processes performing an exec */
1792#ifdef CONFIG_SMP
1793extern void sched_exec(void);
1794#else
1795#define sched_exec()   {}
1796#endif
1797
1798extern void sched_clock_idle_sleep_event(void);
1799extern void sched_clock_idle_wakeup_event(u64 delta_ns);
1800
1801#ifdef CONFIG_HOTPLUG_CPU
1802extern void idle_task_exit(void);
1803#else
1804static inline void idle_task_exit(void) {}
1805#endif
1806
1807extern void sched_idle_next(void);
1808
1809#if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP)
1810extern void wake_up_idle_cpu(int cpu);
1811#else
1812static inline void wake_up_idle_cpu(int cpu) { }
1813#endif
1814
1815extern unsigned int sysctl_sched_latency;
1816extern unsigned int sysctl_sched_min_granularity;
1817extern unsigned int sysctl_sched_wakeup_granularity;
1818extern unsigned int sysctl_sched_shares_ratelimit;
1819extern unsigned int sysctl_sched_shares_thresh;
1820#ifdef CONFIG_SCHED_DEBUG
1821extern unsigned int sysctl_sched_child_runs_first;
1822extern unsigned int sysctl_sched_features;
1823extern unsigned int sysctl_sched_migration_cost;
1824extern unsigned int sysctl_sched_nr_migrate;
1825extern unsigned int sysctl_timer_migration;
1826
1827int sched_nr_latency_handler(struct ctl_table *table, int write,
1828		struct file *file, void __user *buffer, size_t *length,
1829		loff_t *ppos);
1830#endif
1831#ifdef CONFIG_SCHED_DEBUG
1832static inline unsigned int get_sysctl_timer_migration(void)
1833{
1834	return sysctl_timer_migration;
1835}
1836#else
1837static inline unsigned int get_sysctl_timer_migration(void)
1838{
1839	return 1;
1840}
1841#endif
1842extern unsigned int sysctl_sched_rt_period;
1843extern int sysctl_sched_rt_runtime;
1844
1845int sched_rt_handler(struct ctl_table *table, int write,
1846		struct file *filp, void __user *buffer, size_t *lenp,
1847		loff_t *ppos);
1848
1849extern unsigned int sysctl_sched_compat_yield;
1850
1851#ifdef CONFIG_RT_MUTEXES
1852extern int rt_mutex_getprio(struct task_struct *p);
1853extern void rt_mutex_setprio(struct task_struct *p, int prio);
1854extern void rt_mutex_adjust_pi(struct task_struct *p);
1855#else
1856static inline int rt_mutex_getprio(struct task_struct *p)
1857{
1858	return p->normal_prio;
1859}
1860# define rt_mutex_adjust_pi(p)		do { } while (0)
1861#endif
1862
1863extern void set_user_nice(struct task_struct *p, long nice);
1864extern int task_prio(const struct task_struct *p);
1865extern int task_nice(const struct task_struct *p);
1866extern int can_nice(const struct task_struct *p, const int nice);
1867extern int task_curr(const struct task_struct *p);
1868extern int idle_cpu(int cpu);
1869extern int sched_setscheduler(struct task_struct *, int, struct sched_param *);
1870extern int sched_setscheduler_nocheck(struct task_struct *, int,
1871				      struct sched_param *);
1872extern struct task_struct *idle_task(int cpu);
1873extern struct task_struct *curr_task(int cpu);
1874extern void set_curr_task(int cpu, struct task_struct *p);
1875
1876void yield(void);
1877
1878/*
1879 * The default (Linux) execution domain.
1880 */
1881extern struct exec_domain	default_exec_domain;
1882
1883union thread_union {
1884	struct thread_info thread_info;
1885	unsigned long stack[THREAD_SIZE/sizeof(long)];
1886};
1887
1888#ifndef __HAVE_ARCH_KSTACK_END
1889static inline int kstack_end(void *addr)
1890{
1891	/* Reliable end of stack detection:
1892	 * Some APM bios versions misalign the stack
1893	 */
1894	return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
1895}
1896#endif
1897
1898extern union thread_union init_thread_union;
1899extern struct task_struct init_task;
1900
1901extern struct   mm_struct init_mm;
1902
1903extern struct pid_namespace init_pid_ns;
1904
1905/*
1906 * find a task by one of its numerical ids
1907 *
1908 * find_task_by_pid_ns():
1909 *      finds a task by its pid in the specified namespace
1910 * find_task_by_vpid():
1911 *      finds a task by its virtual pid
1912 *
1913 * see also find_vpid() etc in include/linux/pid.h
1914 */
1915
1916extern struct task_struct *find_task_by_vpid(pid_t nr);
1917extern struct task_struct *find_task_by_pid_ns(pid_t nr,
1918		struct pid_namespace *ns);
1919
1920extern void __set_special_pids(struct pid *pid);
1921
1922/* per-UID process charging. */
1923extern struct user_struct * alloc_uid(struct user_namespace *, uid_t);
1924static inline struct user_struct *get_uid(struct user_struct *u)
1925{
1926	atomic_inc(&u->__count);
1927	return u;
1928}
1929extern void free_uid(struct user_struct *);
1930extern void release_uids(struct user_namespace *ns);
1931
1932#include <asm/current.h>
1933
1934extern void do_timer(unsigned long ticks);
1935
1936extern int wake_up_state(struct task_struct *tsk, unsigned int state);
1937extern int wake_up_process(struct task_struct *tsk);
1938extern void wake_up_new_task(struct task_struct *tsk,
1939				unsigned long clone_flags);
1940#ifdef CONFIG_SMP
1941 extern void kick_process(struct task_struct *tsk);
1942#else
1943 static inline void kick_process(struct task_struct *tsk) { }
1944#endif
1945extern void sched_fork(struct task_struct *p, int clone_flags);
1946extern void sched_dead(struct task_struct *p);
1947
1948extern void proc_caches_init(void);
1949extern void flush_signals(struct task_struct *);
1950extern void __flush_signals(struct task_struct *);
1951extern void ignore_signals(struct task_struct *);
1952extern void flush_signal_handlers(struct task_struct *, int force_default);
1953extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
1954
1955static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
1956{
1957	unsigned long flags;
1958	int ret;
1959
1960	spin_lock_irqsave(&tsk->sighand->siglock, flags);
1961	ret = dequeue_signal(tsk, mask, info);
1962	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
1963
1964	return ret;
1965}
1966
1967extern void block_all_signals(int (*notifier)(void *priv), void *priv,
1968			      sigset_t *mask);
1969extern void unblock_all_signals(void);
1970extern void release_task(struct task_struct * p);
1971extern int send_sig_info(int, struct siginfo *, struct task_struct *);
1972extern int force_sigsegv(int, struct task_struct *);
1973extern int force_sig_info(int, struct siginfo *, struct task_struct *);
1974extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
1975extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
1976extern int kill_pid_info_as_uid(int, struct siginfo *, struct pid *, uid_t, uid_t, u32);
1977extern int kill_pgrp(struct pid *pid, int sig, int priv);
1978extern int kill_pid(struct pid *pid, int sig, int priv);
1979extern int kill_proc_info(int, struct siginfo *, pid_t);
1980extern int do_notify_parent(struct task_struct *, int);
1981extern void force_sig(int, struct task_struct *);
1982extern void force_sig_specific(int, struct task_struct *);
1983extern int send_sig(int, struct task_struct *, int);
1984extern void zap_other_threads(struct task_struct *p);
1985extern struct sigqueue *sigqueue_alloc(void);
1986extern void sigqueue_free(struct sigqueue *);
1987extern int send_sigqueue(struct sigqueue *,  struct task_struct *, int group);
1988extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
1989extern int do_sigaltstack(const stack_t __user *, stack_t __user *, unsigned long);
1990
1991static inline int kill_cad_pid(int sig, int priv)
1992{
1993	return kill_pid(cad_pid, sig, priv);
1994}
1995
1996/* These can be the second arg to send_sig_info/send_group_sig_info.  */
1997#define SEND_SIG_NOINFO ((struct siginfo *) 0)
1998#define SEND_SIG_PRIV	((struct siginfo *) 1)
1999#define SEND_SIG_FORCED	((struct siginfo *) 2)
2000
2001static inline int is_si_special(const struct siginfo *info)
2002{
2003	return info <= SEND_SIG_FORCED;
2004}
2005
2006/* True if we are on the alternate signal stack.  */
2007
2008static inline int on_sig_stack(unsigned long sp)
2009{
2010	return (sp - current->sas_ss_sp < current->sas_ss_size);
2011}
2012
2013static inline int sas_ss_flags(unsigned long sp)
2014{
2015	return (current->sas_ss_size == 0 ? SS_DISABLE
2016		: on_sig_stack(sp) ? SS_ONSTACK : 0);
2017}
2018
2019/*
2020 * Routines for handling mm_structs
2021 */
2022extern struct mm_struct * mm_alloc(void);
2023
2024/* mmdrop drops the mm and the page tables */
2025extern void __mmdrop(struct mm_struct *);
2026static inline void mmdrop(struct mm_struct * mm)
2027{
2028	if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2029		__mmdrop(mm);
2030}
2031
2032/* mmput gets rid of the mappings and all user-space */
2033extern void mmput(struct mm_struct *);
2034/* Grab a reference to a task's mm, if it is not already going away */
2035extern struct mm_struct *get_task_mm(struct task_struct *task);
2036/* Remove the current tasks stale references to the old mm_struct */
2037extern void mm_release(struct task_struct *, struct mm_struct *);
2038/* Allocate a new mm structure and copy contents from tsk->mm */
2039extern struct mm_struct *dup_mm(struct task_struct *tsk);
2040
2041extern int copy_thread(unsigned long, unsigned long, unsigned long,
2042			struct task_struct *, struct pt_regs *);
2043extern void flush_thread(void);
2044extern void exit_thread(void);
2045
2046extern void exit_files(struct task_struct *);
2047extern void __cleanup_signal(struct signal_struct *);
2048extern void __cleanup_sighand(struct sighand_struct *);
2049
2050extern void exit_itimers(struct signal_struct *);
2051extern void flush_itimer_signals(void);
2052
2053extern NORET_TYPE void do_group_exit(int);
2054
2055extern void daemonize(const char *, ...);
2056extern int allow_signal(int);
2057extern int disallow_signal(int);
2058
2059extern int do_execve(char *, char __user * __user *, char __user * __user *, struct pt_regs *);
2060extern long do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *);
2061struct task_struct *fork_idle(int);
2062
2063extern void set_task_comm(struct task_struct *tsk, char *from);
2064extern char *get_task_comm(char *to, struct task_struct *tsk);
2065
2066#ifdef CONFIG_SMP
2067extern void wait_task_context_switch(struct task_struct *p);
2068extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
2069#else
2070static inline void wait_task_context_switch(struct task_struct *p) {}
2071static inline unsigned long wait_task_inactive(struct task_struct *p,
2072					       long match_state)
2073{
2074	return 1;
2075}
2076#endif
2077
2078#define next_task(p) \
2079	list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
2080
2081#define for_each_process(p) \
2082	for (p = &init_task ; (p = next_task(p)) != &init_task ; )
2083
2084extern bool is_single_threaded(struct task_struct *);
2085
2086/*
2087 * Careful: do_each_thread/while_each_thread is a double loop so
2088 *          'break' will not work as expected - use goto instead.
2089 */
2090#define do_each_thread(g, t) \
2091	for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
2092
2093#define while_each_thread(g, t) \
2094	while ((t = next_thread(t)) != g)
2095
2096/* de_thread depends on thread_group_leader not being a pid based check */
2097#define thread_group_leader(p)	(p == p->group_leader)
2098
2099/* Do to the insanities of de_thread it is possible for a process
2100 * to have the pid of the thread group leader without actually being
2101 * the thread group leader.  For iteration through the pids in proc
2102 * all we care about is that we have a task with the appropriate
2103 * pid, we don't actually care if we have the right task.
2104 */
2105static inline int has_group_leader_pid(struct task_struct *p)
2106{
2107	return p->pid == p->tgid;
2108}
2109
2110static inline
2111int same_thread_group(struct task_struct *p1, struct task_struct *p2)
2112{
2113	return p1->tgid == p2->tgid;
2114}
2115
2116static inline struct task_struct *next_thread(const struct task_struct *p)
2117{
2118	return list_entry_rcu(p->thread_group.next,
2119			      struct task_struct, thread_group);
2120}
2121
2122static inline int thread_group_empty(struct task_struct *p)
2123{
2124	return list_empty(&p->thread_group);
2125}
2126
2127#define delay_group_leader(p) \
2128		(thread_group_leader(p) && !thread_group_empty(p))
2129
2130static inline int task_detached(struct task_struct *p)
2131{
2132	return p->exit_signal == -1;
2133}
2134
2135/*
2136 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
2137 * subscriptions and synchronises with wait4().  Also used in procfs.  Also
2138 * pins the final release of task.io_context.  Also protects ->cpuset and
2139 * ->cgroup.subsys[].
2140 *
2141 * Nests both inside and outside of read_lock(&tasklist_lock).
2142 * It must not be nested with write_lock_irq(&tasklist_lock),
2143 * neither inside nor outside.
2144 */
2145static inline void task_lock(struct task_struct *p)
2146{
2147	spin_lock(&p->alloc_lock);
2148}
2149
2150static inline void task_unlock(struct task_struct *p)
2151{
2152	spin_unlock(&p->alloc_lock);
2153}
2154
2155extern struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
2156							unsigned long *flags);
2157
2158static inline void unlock_task_sighand(struct task_struct *tsk,
2159						unsigned long *flags)
2160{
2161	spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
2162}
2163
2164#ifndef __HAVE_THREAD_FUNCTIONS
2165
2166#define task_thread_info(task)	((struct thread_info *)(task)->stack)
2167#define task_stack_page(task)	((task)->stack)
2168
2169static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
2170{
2171	*task_thread_info(p) = *task_thread_info(org);
2172	task_thread_info(p)->task = p;
2173}
2174
2175static inline unsigned long *end_of_stack(struct task_struct *p)
2176{
2177	return (unsigned long *)(task_thread_info(p) + 1);
2178}
2179
2180#endif
2181
2182static inline int object_is_on_stack(void *obj)
2183{
2184	void *stack = task_stack_page(current);
2185
2186	return (obj >= stack) && (obj < (stack + THREAD_SIZE));
2187}
2188
2189extern void thread_info_cache_init(void);
2190
2191#ifdef CONFIG_DEBUG_STACK_USAGE
2192static inline unsigned long stack_not_used(struct task_struct *p)
2193{
2194	unsigned long *n = end_of_stack(p);
2195
2196	do { 	/* Skip over canary */
2197		n++;
2198	} while (!*n);
2199
2200	return (unsigned long)n - (unsigned long)end_of_stack(p);
2201}
2202#endif
2203
2204/* set thread flags in other task's structures
2205 * - see asm/thread_info.h for TIF_xxxx flags available
2206 */
2207static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2208{
2209	set_ti_thread_flag(task_thread_info(tsk), flag);
2210}
2211
2212static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2213{
2214	clear_ti_thread_flag(task_thread_info(tsk), flag);
2215}
2216
2217static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2218{
2219	return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2220}
2221
2222static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2223{
2224	return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2225}
2226
2227static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2228{
2229	return test_ti_thread_flag(task_thread_info(tsk), flag);
2230}
2231
2232static inline void set_tsk_need_resched(struct task_struct *tsk)
2233{
2234	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2235}
2236
2237static inline void clear_tsk_need_resched(struct task_struct *tsk)
2238{
2239	clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2240}
2241
2242static inline int test_tsk_need_resched(struct task_struct *tsk)
2243{
2244	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2245}
2246
2247static inline int restart_syscall(void)
2248{
2249	set_tsk_thread_flag(current, TIF_SIGPENDING);
2250	return -ERESTARTNOINTR;
2251}
2252
2253static inline int signal_pending(struct task_struct *p)
2254{
2255	return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
2256}
2257
2258extern int __fatal_signal_pending(struct task_struct *p);
2259
2260static inline int fatal_signal_pending(struct task_struct *p)
2261{
2262	return signal_pending(p) && __fatal_signal_pending(p);
2263}
2264
2265static inline int signal_pending_state(long state, struct task_struct *p)
2266{
2267	if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
2268		return 0;
2269	if (!signal_pending(p))
2270		return 0;
2271
2272	return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
2273}
2274
2275static inline int need_resched(void)
2276{
2277	return unlikely(test_thread_flag(TIF_NEED_RESCHED));
2278}
2279
2280/*
2281 * cond_resched() and cond_resched_lock(): latency reduction via
2282 * explicit rescheduling in places that are safe. The return
2283 * value indicates whether a reschedule was done in fact.
2284 * cond_resched_lock() will drop the spinlock before scheduling,
2285 * cond_resched_softirq() will enable bhs before scheduling.
2286 */
2287extern int _cond_resched(void);
2288
2289#define cond_resched() ({			\
2290	__might_sleep(__FILE__, __LINE__, 0);	\
2291	_cond_resched();			\
2292})
2293
2294extern int __cond_resched_lock(spinlock_t *lock);
2295
2296#ifdef CONFIG_PREEMPT
2297#define PREEMPT_LOCK_OFFSET	PREEMPT_OFFSET
2298#else
2299#define PREEMPT_LOCK_OFFSET	0
2300#endif
2301
2302#define cond_resched_lock(lock) ({				\
2303	__might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);	\
2304	__cond_resched_lock(lock);				\
2305})
2306
2307extern int __cond_resched_softirq(void);
2308
2309#define cond_resched_softirq() ({				\
2310	__might_sleep(__FILE__, __LINE__, SOFTIRQ_OFFSET);	\
2311	__cond_resched_softirq();				\
2312})
2313
2314/*
2315 * Does a critical section need to be broken due to another
2316 * task waiting?: (technically does not depend on CONFIG_PREEMPT,
2317 * but a general need for low latency)
2318 */
2319static inline int spin_needbreak(spinlock_t *lock)
2320{
2321#ifdef CONFIG_PREEMPT
2322	return spin_is_contended(lock);
2323#else
2324	return 0;
2325#endif
2326}
2327
2328/*
2329 * Thread group CPU time accounting.
2330 */
2331void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
2332void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
2333
2334static inline void thread_group_cputime_init(struct signal_struct *sig)
2335{
2336	sig->cputimer.cputime = INIT_CPUTIME;
2337	spin_lock_init(&sig->cputimer.lock);
2338	sig->cputimer.running = 0;
2339}
2340
2341static inline void thread_group_cputime_free(struct signal_struct *sig)
2342{
2343}
2344
2345/*
2346 * Reevaluate whether the task has signals pending delivery.
2347 * Wake the task if so.
2348 * This is required every time the blocked sigset_t changes.
2349 * callers must hold sighand->siglock.
2350 */
2351extern void recalc_sigpending_and_wake(struct task_struct *t);
2352extern void recalc_sigpending(void);
2353
2354extern void signal_wake_up(struct task_struct *t, int resume_stopped);
2355
2356/*
2357 * Wrappers for p->thread_info->cpu access. No-op on UP.
2358 */
2359#ifdef CONFIG_SMP
2360
2361static inline unsigned int task_cpu(const struct task_struct *p)
2362{
2363	return task_thread_info(p)->cpu;
2364}
2365
2366extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2367
2368#else
2369
2370static inline unsigned int task_cpu(const struct task_struct *p)
2371{
2372	return 0;
2373}
2374
2375static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2376{
2377}
2378
2379#endif /* CONFIG_SMP */
2380
2381extern void arch_pick_mmap_layout(struct mm_struct *mm);
2382
2383#ifdef CONFIG_TRACING
2384extern void
2385__trace_special(void *__tr, void *__data,
2386		unsigned long arg1, unsigned long arg2, unsigned long arg3);
2387#else
2388static inline void
2389__trace_special(void *__tr, void *__data,
2390		unsigned long arg1, unsigned long arg2, unsigned long arg3)
2391{
2392}
2393#endif
2394
2395extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2396extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2397
2398extern void normalize_rt_tasks(void);
2399
2400#ifdef CONFIG_GROUP_SCHED
2401
2402extern struct task_group init_task_group;
2403#ifdef CONFIG_USER_SCHED
2404extern struct task_group root_task_group;
2405extern void set_tg_uid(struct user_struct *user);
2406#endif
2407
2408extern struct task_group *sched_create_group(struct task_group *parent);
2409extern void sched_destroy_group(struct task_group *tg);
2410extern void sched_move_task(struct task_struct *tsk);
2411#ifdef CONFIG_FAIR_GROUP_SCHED
2412extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
2413extern unsigned long sched_group_shares(struct task_group *tg);
2414#endif
2415#ifdef CONFIG_RT_GROUP_SCHED
2416extern int sched_group_set_rt_runtime(struct task_group *tg,
2417				      long rt_runtime_us);
2418extern long sched_group_rt_runtime(struct task_group *tg);
2419extern int sched_group_set_rt_period(struct task_group *tg,
2420				      long rt_period_us);
2421extern long sched_group_rt_period(struct task_group *tg);
2422extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk);
2423#endif
2424#endif
2425
2426extern int task_can_switch_user(struct user_struct *up,
2427					struct task_struct *tsk);
2428
2429#ifdef CONFIG_TASK_XACCT
2430static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2431{
2432	tsk->ioac.rchar += amt;
2433}
2434
2435static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2436{
2437	tsk->ioac.wchar += amt;
2438}
2439
2440static inline void inc_syscr(struct task_struct *tsk)
2441{
2442	tsk->ioac.syscr++;
2443}
2444
2445static inline void inc_syscw(struct task_struct *tsk)
2446{
2447	tsk->ioac.syscw++;
2448}
2449#else
2450static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2451{
2452}
2453
2454static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2455{
2456}
2457
2458static inline void inc_syscr(struct task_struct *tsk)
2459{
2460}
2461
2462static inline void inc_syscw(struct task_struct *tsk)
2463{
2464}
2465#endif
2466
2467#ifndef TASK_SIZE_OF
2468#define TASK_SIZE_OF(tsk)	TASK_SIZE
2469#endif
2470
2471/*
2472 * Call the function if the target task is executing on a CPU right now:
2473 */
2474extern void task_oncpu_function_call(struct task_struct *p,
2475				     void (*func) (void *info), void *info);
2476
2477
2478#ifdef CONFIG_MM_OWNER
2479extern void mm_update_next_owner(struct mm_struct *mm);
2480extern void mm_init_owner(struct mm_struct *mm, struct task_struct *p);
2481#else
2482static inline void mm_update_next_owner(struct mm_struct *mm)
2483{
2484}
2485
2486static inline void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
2487{
2488}
2489#endif /* CONFIG_MM_OWNER */
2490
2491#define TASK_STATE_TO_CHAR_STR "RSDTtZX"
2492
2493#endif /* __KERNEL__ */
2494
2495#endif
2496