xref: /linux/include/linux/sched.h (revision f58c91ce82cbb55a48fbc1a0cb7c84c0d0a4e1bd)
1 #ifndef _LINUX_SCHED_H
2 #define _LINUX_SCHED_H
3 
4 #include <uapi/linux/sched.h>
5 
6 
7 struct sched_param {
8 	int sched_priority;
9 };
10 
11 #include <asm/param.h>	/* for HZ */
12 
13 #include <linux/capability.h>
14 #include <linux/threads.h>
15 #include <linux/kernel.h>
16 #include <linux/types.h>
17 #include <linux/timex.h>
18 #include <linux/jiffies.h>
19 #include <linux/rbtree.h>
20 #include <linux/thread_info.h>
21 #include <linux/cpumask.h>
22 #include <linux/errno.h>
23 #include <linux/nodemask.h>
24 #include <linux/mm_types.h>
25 #include <linux/preempt_mask.h>
26 
27 #include <asm/page.h>
28 #include <asm/ptrace.h>
29 #include <asm/cputime.h>
30 
31 #include <linux/smp.h>
32 #include <linux/sem.h>
33 #include <linux/signal.h>
34 #include <linux/compiler.h>
35 #include <linux/completion.h>
36 #include <linux/pid.h>
37 #include <linux/percpu.h>
38 #include <linux/topology.h>
39 #include <linux/proportions.h>
40 #include <linux/seccomp.h>
41 #include <linux/rcupdate.h>
42 #include <linux/rculist.h>
43 #include <linux/rtmutex.h>
44 
45 #include <linux/time.h>
46 #include <linux/param.h>
47 #include <linux/resource.h>
48 #include <linux/timer.h>
49 #include <linux/hrtimer.h>
50 #include <linux/task_io_accounting.h>
51 #include <linux/latencytop.h>
52 #include <linux/cred.h>
53 #include <linux/llist.h>
54 #include <linux/uidgid.h>
55 #include <linux/gfp.h>
56 
57 #include <asm/processor.h>
58 
59 struct exec_domain;
60 struct futex_pi_state;
61 struct robust_list_head;
62 struct bio_list;
63 struct fs_struct;
64 struct perf_event_context;
65 struct blk_plug;
66 
67 /*
68  * List of flags we want to share for kernel threads,
69  * if only because they are not used by them anyway.
70  */
71 #define CLONE_KERNEL	(CLONE_FS | CLONE_FILES | CLONE_SIGHAND)
72 
73 /*
74  * These are the constant used to fake the fixed-point load-average
75  * counting. Some notes:
76  *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
77  *    a load-average precision of 10 bits integer + 11 bits fractional
78  *  - if you want to count load-averages more often, you need more
79  *    precision, or rounding will get you. With 2-second counting freq,
80  *    the EXP_n values would be 1981, 2034 and 2043 if still using only
81  *    11 bit fractions.
82  */
83 extern unsigned long avenrun[];		/* Load averages */
84 extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
85 
86 #define FSHIFT		11		/* nr of bits of precision */
87 #define FIXED_1		(1<<FSHIFT)	/* 1.0 as fixed-point */
88 #define LOAD_FREQ	(5*HZ+1)	/* 5 sec intervals */
89 #define EXP_1		1884		/* 1/exp(5sec/1min) as fixed-point */
90 #define EXP_5		2014		/* 1/exp(5sec/5min) */
91 #define EXP_15		2037		/* 1/exp(5sec/15min) */
92 
93 #define CALC_LOAD(load,exp,n) \
94 	load *= exp; \
95 	load += n*(FIXED_1-exp); \
96 	load >>= FSHIFT;
97 
98 extern unsigned long total_forks;
99 extern int nr_threads;
100 DECLARE_PER_CPU(unsigned long, process_counts);
101 extern int nr_processes(void);
102 extern unsigned long nr_running(void);
103 extern unsigned long nr_iowait(void);
104 extern unsigned long nr_iowait_cpu(int cpu);
105 extern unsigned long this_cpu_load(void);
106 
107 
108 extern void calc_global_load(unsigned long ticks);
109 extern void update_cpu_load_nohz(void);
110 
111 extern unsigned long get_parent_ip(unsigned long addr);
112 
113 extern void dump_cpu_task(int cpu);
114 
115 struct seq_file;
116 struct cfs_rq;
117 struct task_group;
118 #ifdef CONFIG_SCHED_DEBUG
119 extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
120 extern void proc_sched_set_task(struct task_struct *p);
121 extern void
122 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
123 #endif
124 
125 /*
126  * Task state bitmask. NOTE! These bits are also
127  * encoded in fs/proc/array.c: get_task_state().
128  *
129  * We have two separate sets of flags: task->state
130  * is about runnability, while task->exit_state are
131  * about the task exiting. Confusing, but this way
132  * modifying one set can't modify the other one by
133  * mistake.
134  */
135 #define TASK_RUNNING		0
136 #define TASK_INTERRUPTIBLE	1
137 #define TASK_UNINTERRUPTIBLE	2
138 #define __TASK_STOPPED		4
139 #define __TASK_TRACED		8
140 /* in tsk->exit_state */
141 #define EXIT_ZOMBIE		16
142 #define EXIT_DEAD		32
143 /* in tsk->state again */
144 #define TASK_DEAD		64
145 #define TASK_WAKEKILL		128
146 #define TASK_WAKING		256
147 #define TASK_PARKED		512
148 #define TASK_STATE_MAX		1024
149 
150 #define TASK_STATE_TO_CHAR_STR "RSDTtZXxKWP"
151 
152 extern char ___assert_task_state[1 - 2*!!(
153 		sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
154 
155 /* Convenience macros for the sake of set_task_state */
156 #define TASK_KILLABLE		(TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
157 #define TASK_STOPPED		(TASK_WAKEKILL | __TASK_STOPPED)
158 #define TASK_TRACED		(TASK_WAKEKILL | __TASK_TRACED)
159 
160 /* Convenience macros for the sake of wake_up */
161 #define TASK_NORMAL		(TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
162 #define TASK_ALL		(TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
163 
164 /* get_task_state() */
165 #define TASK_REPORT		(TASK_RUNNING | TASK_INTERRUPTIBLE | \
166 				 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
167 				 __TASK_TRACED)
168 
169 #define task_is_traced(task)	((task->state & __TASK_TRACED) != 0)
170 #define task_is_stopped(task)	((task->state & __TASK_STOPPED) != 0)
171 #define task_is_dead(task)	((task)->exit_state != 0)
172 #define task_is_stopped_or_traced(task)	\
173 			((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
174 #define task_contributes_to_load(task)	\
175 				((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
176 				 (task->flags & PF_FROZEN) == 0)
177 
178 #define __set_task_state(tsk, state_value)		\
179 	do { (tsk)->state = (state_value); } while (0)
180 #define set_task_state(tsk, state_value)		\
181 	set_mb((tsk)->state, (state_value))
182 
183 /*
184  * set_current_state() includes a barrier so that the write of current->state
185  * is correctly serialised wrt the caller's subsequent test of whether to
186  * actually sleep:
187  *
188  *	set_current_state(TASK_UNINTERRUPTIBLE);
189  *	if (do_i_need_to_sleep())
190  *		schedule();
191  *
192  * If the caller does not need such serialisation then use __set_current_state()
193  */
194 #define __set_current_state(state_value)			\
195 	do { current->state = (state_value); } while (0)
196 #define set_current_state(state_value)		\
197 	set_mb(current->state, (state_value))
198 
199 /* Task command name length */
200 #define TASK_COMM_LEN 16
201 
202 #include <linux/spinlock.h>
203 
204 /*
205  * This serializes "schedule()" and also protects
206  * the run-queue from deletions/modifications (but
207  * _adding_ to the beginning of the run-queue has
208  * a separate lock).
209  */
210 extern rwlock_t tasklist_lock;
211 extern spinlock_t mmlist_lock;
212 
213 struct task_struct;
214 
215 #ifdef CONFIG_PROVE_RCU
216 extern int lockdep_tasklist_lock_is_held(void);
217 #endif /* #ifdef CONFIG_PROVE_RCU */
218 
219 extern void sched_init(void);
220 extern void sched_init_smp(void);
221 extern asmlinkage void schedule_tail(struct task_struct *prev);
222 extern void init_idle(struct task_struct *idle, int cpu);
223 extern void init_idle_bootup_task(struct task_struct *idle);
224 
225 extern int runqueue_is_locked(int cpu);
226 
227 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
228 extern void nohz_balance_enter_idle(int cpu);
229 extern void set_cpu_sd_state_idle(void);
230 extern int get_nohz_timer_target(void);
231 #else
232 static inline void nohz_balance_enter_idle(int cpu) { }
233 static inline void set_cpu_sd_state_idle(void) { }
234 #endif
235 
236 /*
237  * Only dump TASK_* tasks. (0 for all tasks)
238  */
239 extern void show_state_filter(unsigned long state_filter);
240 
241 static inline void show_state(void)
242 {
243 	show_state_filter(0);
244 }
245 
246 extern void show_regs(struct pt_regs *);
247 
248 /*
249  * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
250  * task), SP is the stack pointer of the first frame that should be shown in the back
251  * trace (or NULL if the entire call-chain of the task should be shown).
252  */
253 extern void show_stack(struct task_struct *task, unsigned long *sp);
254 
255 void io_schedule(void);
256 long io_schedule_timeout(long timeout);
257 
258 extern void cpu_init (void);
259 extern void trap_init(void);
260 extern void update_process_times(int user);
261 extern void scheduler_tick(void);
262 
263 extern void sched_show_task(struct task_struct *p);
264 
265 #ifdef CONFIG_LOCKUP_DETECTOR
266 extern void touch_softlockup_watchdog(void);
267 extern void touch_softlockup_watchdog_sync(void);
268 extern void touch_all_softlockup_watchdogs(void);
269 extern int proc_dowatchdog_thresh(struct ctl_table *table, int write,
270 				  void __user *buffer,
271 				  size_t *lenp, loff_t *ppos);
272 extern unsigned int  softlockup_panic;
273 void lockup_detector_init(void);
274 #else
275 static inline void touch_softlockup_watchdog(void)
276 {
277 }
278 static inline void touch_softlockup_watchdog_sync(void)
279 {
280 }
281 static inline void touch_all_softlockup_watchdogs(void)
282 {
283 }
284 static inline void lockup_detector_init(void)
285 {
286 }
287 #endif
288 
289 #ifdef CONFIG_DETECT_HUNG_TASK
290 void reset_hung_task_detector(void);
291 #else
292 static inline void reset_hung_task_detector(void)
293 {
294 }
295 #endif
296 
297 /* Attach to any functions which should be ignored in wchan output. */
298 #define __sched		__attribute__((__section__(".sched.text")))
299 
300 /* Linker adds these: start and end of __sched functions */
301 extern char __sched_text_start[], __sched_text_end[];
302 
303 /* Is this address in the __sched functions? */
304 extern int in_sched_functions(unsigned long addr);
305 
306 #define	MAX_SCHEDULE_TIMEOUT	LONG_MAX
307 extern signed long schedule_timeout(signed long timeout);
308 extern signed long schedule_timeout_interruptible(signed long timeout);
309 extern signed long schedule_timeout_killable(signed long timeout);
310 extern signed long schedule_timeout_uninterruptible(signed long timeout);
311 asmlinkage void schedule(void);
312 extern void schedule_preempt_disabled(void);
313 
314 struct nsproxy;
315 struct user_namespace;
316 
317 #ifdef CONFIG_MMU
318 extern void arch_pick_mmap_layout(struct mm_struct *mm);
319 extern unsigned long
320 arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
321 		       unsigned long, unsigned long);
322 extern unsigned long
323 arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
324 			  unsigned long len, unsigned long pgoff,
325 			  unsigned long flags);
326 #else
327 static inline void arch_pick_mmap_layout(struct mm_struct *mm) {}
328 #endif
329 
330 
331 extern void set_dumpable(struct mm_struct *mm, int value);
332 extern int get_dumpable(struct mm_struct *mm);
333 
334 #define SUID_DUMP_DISABLE	0	/* No setuid dumping */
335 #define SUID_DUMP_USER		1	/* Dump as user of process */
336 #define SUID_DUMP_ROOT		2	/* Dump as root */
337 
338 /* mm flags */
339 /* dumpable bits */
340 #define MMF_DUMPABLE      0  /* core dump is permitted */
341 #define MMF_DUMP_SECURELY 1  /* core file is readable only by root */
342 
343 #define MMF_DUMPABLE_BITS 2
344 #define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
345 
346 /* coredump filter bits */
347 #define MMF_DUMP_ANON_PRIVATE	2
348 #define MMF_DUMP_ANON_SHARED	3
349 #define MMF_DUMP_MAPPED_PRIVATE	4
350 #define MMF_DUMP_MAPPED_SHARED	5
351 #define MMF_DUMP_ELF_HEADERS	6
352 #define MMF_DUMP_HUGETLB_PRIVATE 7
353 #define MMF_DUMP_HUGETLB_SHARED  8
354 
355 #define MMF_DUMP_FILTER_SHIFT	MMF_DUMPABLE_BITS
356 #define MMF_DUMP_FILTER_BITS	7
357 #define MMF_DUMP_FILTER_MASK \
358 	(((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
359 #define MMF_DUMP_FILTER_DEFAULT \
360 	((1 << MMF_DUMP_ANON_PRIVATE) |	(1 << MMF_DUMP_ANON_SHARED) |\
361 	 (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
362 
363 #ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
364 # define MMF_DUMP_MASK_DEFAULT_ELF	(1 << MMF_DUMP_ELF_HEADERS)
365 #else
366 # define MMF_DUMP_MASK_DEFAULT_ELF	0
367 #endif
368 					/* leave room for more dump flags */
369 #define MMF_VM_MERGEABLE	16	/* KSM may merge identical pages */
370 #define MMF_VM_HUGEPAGE		17	/* set when VM_HUGEPAGE is set on vma */
371 #define MMF_EXE_FILE_CHANGED	18	/* see prctl_set_mm_exe_file() */
372 
373 #define MMF_HAS_UPROBES		19	/* has uprobes */
374 #define MMF_RECALC_UPROBES	20	/* MMF_HAS_UPROBES can be wrong */
375 
376 #define MMF_INIT_MASK		(MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
377 
378 struct sighand_struct {
379 	atomic_t		count;
380 	struct k_sigaction	action[_NSIG];
381 	spinlock_t		siglock;
382 	wait_queue_head_t	signalfd_wqh;
383 };
384 
385 struct pacct_struct {
386 	int			ac_flag;
387 	long			ac_exitcode;
388 	unsigned long		ac_mem;
389 	cputime_t		ac_utime, ac_stime;
390 	unsigned long		ac_minflt, ac_majflt;
391 };
392 
393 struct cpu_itimer {
394 	cputime_t expires;
395 	cputime_t incr;
396 	u32 error;
397 	u32 incr_error;
398 };
399 
400 /**
401  * struct cputime - snaphsot of system and user cputime
402  * @utime: time spent in user mode
403  * @stime: time spent in system mode
404  *
405  * Gathers a generic snapshot of user and system time.
406  */
407 struct cputime {
408 	cputime_t utime;
409 	cputime_t stime;
410 };
411 
412 /**
413  * struct task_cputime - collected CPU time counts
414  * @utime:		time spent in user mode, in &cputime_t units
415  * @stime:		time spent in kernel mode, in &cputime_t units
416  * @sum_exec_runtime:	total time spent on the CPU, in nanoseconds
417  *
418  * This is an extension of struct cputime that includes the total runtime
419  * spent by the task from the scheduler point of view.
420  *
421  * As a result, this structure groups together three kinds of CPU time
422  * that are tracked for threads and thread groups.  Most things considering
423  * CPU time want to group these counts together and treat all three
424  * of them in parallel.
425  */
426 struct task_cputime {
427 	cputime_t utime;
428 	cputime_t stime;
429 	unsigned long long sum_exec_runtime;
430 };
431 /* Alternate field names when used to cache expirations. */
432 #define prof_exp	stime
433 #define virt_exp	utime
434 #define sched_exp	sum_exec_runtime
435 
436 #define INIT_CPUTIME	\
437 	(struct task_cputime) {					\
438 		.utime = 0,					\
439 		.stime = 0,					\
440 		.sum_exec_runtime = 0,				\
441 	}
442 
443 #define PREEMPT_ENABLED		(PREEMPT_NEED_RESCHED)
444 
445 #ifdef CONFIG_PREEMPT_COUNT
446 #define PREEMPT_DISABLED	(1 + PREEMPT_ENABLED)
447 #else
448 #define PREEMPT_DISABLED	PREEMPT_ENABLED
449 #endif
450 
451 /*
452  * Disable preemption until the scheduler is running.
453  * Reset by start_kernel()->sched_init()->init_idle().
454  *
455  * We include PREEMPT_ACTIVE to avoid cond_resched() from working
456  * before the scheduler is active -- see should_resched().
457  */
458 #define INIT_PREEMPT_COUNT	(PREEMPT_DISABLED + PREEMPT_ACTIVE)
459 
460 /**
461  * struct thread_group_cputimer - thread group interval timer counts
462  * @cputime:		thread group interval timers.
463  * @running:		non-zero when there are timers running and
464  * 			@cputime receives updates.
465  * @lock:		lock for fields in this struct.
466  *
467  * This structure contains the version of task_cputime, above, that is
468  * used for thread group CPU timer calculations.
469  */
470 struct thread_group_cputimer {
471 	struct task_cputime cputime;
472 	int running;
473 	raw_spinlock_t lock;
474 };
475 
476 #include <linux/rwsem.h>
477 struct autogroup;
478 
479 /*
480  * NOTE! "signal_struct" does not have its own
481  * locking, because a shared signal_struct always
482  * implies a shared sighand_struct, so locking
483  * sighand_struct is always a proper superset of
484  * the locking of signal_struct.
485  */
486 struct signal_struct {
487 	atomic_t		sigcnt;
488 	atomic_t		live;
489 	int			nr_threads;
490 
491 	wait_queue_head_t	wait_chldexit;	/* for wait4() */
492 
493 	/* current thread group signal load-balancing target: */
494 	struct task_struct	*curr_target;
495 
496 	/* shared signal handling: */
497 	struct sigpending	shared_pending;
498 
499 	/* thread group exit support */
500 	int			group_exit_code;
501 	/* overloaded:
502 	 * - notify group_exit_task when ->count is equal to notify_count
503 	 * - everyone except group_exit_task is stopped during signal delivery
504 	 *   of fatal signals, group_exit_task processes the signal.
505 	 */
506 	int			notify_count;
507 	struct task_struct	*group_exit_task;
508 
509 	/* thread group stop support, overloads group_exit_code too */
510 	int			group_stop_count;
511 	unsigned int		flags; /* see SIGNAL_* flags below */
512 
513 	/*
514 	 * PR_SET_CHILD_SUBREAPER marks a process, like a service
515 	 * manager, to re-parent orphan (double-forking) child processes
516 	 * to this process instead of 'init'. The service manager is
517 	 * able to receive SIGCHLD signals and is able to investigate
518 	 * the process until it calls wait(). All children of this
519 	 * process will inherit a flag if they should look for a
520 	 * child_subreaper process at exit.
521 	 */
522 	unsigned int		is_child_subreaper:1;
523 	unsigned int		has_child_subreaper:1;
524 
525 	/* POSIX.1b Interval Timers */
526 	int			posix_timer_id;
527 	struct list_head	posix_timers;
528 
529 	/* ITIMER_REAL timer for the process */
530 	struct hrtimer real_timer;
531 	struct pid *leader_pid;
532 	ktime_t it_real_incr;
533 
534 	/*
535 	 * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
536 	 * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
537 	 * values are defined to 0 and 1 respectively
538 	 */
539 	struct cpu_itimer it[2];
540 
541 	/*
542 	 * Thread group totals for process CPU timers.
543 	 * See thread_group_cputimer(), et al, for details.
544 	 */
545 	struct thread_group_cputimer cputimer;
546 
547 	/* Earliest-expiration cache. */
548 	struct task_cputime cputime_expires;
549 
550 	struct list_head cpu_timers[3];
551 
552 	struct pid *tty_old_pgrp;
553 
554 	/* boolean value for session group leader */
555 	int leader;
556 
557 	struct tty_struct *tty; /* NULL if no tty */
558 
559 #ifdef CONFIG_SCHED_AUTOGROUP
560 	struct autogroup *autogroup;
561 #endif
562 	/*
563 	 * Cumulative resource counters for dead threads in the group,
564 	 * and for reaped dead child processes forked by this group.
565 	 * Live threads maintain their own counters and add to these
566 	 * in __exit_signal, except for the group leader.
567 	 */
568 	cputime_t utime, stime, cutime, cstime;
569 	cputime_t gtime;
570 	cputime_t cgtime;
571 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
572 	struct cputime prev_cputime;
573 #endif
574 	unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
575 	unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
576 	unsigned long inblock, oublock, cinblock, coublock;
577 	unsigned long maxrss, cmaxrss;
578 	struct task_io_accounting ioac;
579 
580 	/*
581 	 * Cumulative ns of schedule CPU time fo dead threads in the
582 	 * group, not including a zombie group leader, (This only differs
583 	 * from jiffies_to_ns(utime + stime) if sched_clock uses something
584 	 * other than jiffies.)
585 	 */
586 	unsigned long long sum_sched_runtime;
587 
588 	/*
589 	 * We don't bother to synchronize most readers of this at all,
590 	 * because there is no reader checking a limit that actually needs
591 	 * to get both rlim_cur and rlim_max atomically, and either one
592 	 * alone is a single word that can safely be read normally.
593 	 * getrlimit/setrlimit use task_lock(current->group_leader) to
594 	 * protect this instead of the siglock, because they really
595 	 * have no need to disable irqs.
596 	 */
597 	struct rlimit rlim[RLIM_NLIMITS];
598 
599 #ifdef CONFIG_BSD_PROCESS_ACCT
600 	struct pacct_struct pacct;	/* per-process accounting information */
601 #endif
602 #ifdef CONFIG_TASKSTATS
603 	struct taskstats *stats;
604 #endif
605 #ifdef CONFIG_AUDIT
606 	unsigned audit_tty;
607 	unsigned audit_tty_log_passwd;
608 	struct tty_audit_buf *tty_audit_buf;
609 #endif
610 #ifdef CONFIG_CGROUPS
611 	/*
612 	 * group_rwsem prevents new tasks from entering the threadgroup and
613 	 * member tasks from exiting,a more specifically, setting of
614 	 * PF_EXITING.  fork and exit paths are protected with this rwsem
615 	 * using threadgroup_change_begin/end().  Users which require
616 	 * threadgroup to remain stable should use threadgroup_[un]lock()
617 	 * which also takes care of exec path.  Currently, cgroup is the
618 	 * only user.
619 	 */
620 	struct rw_semaphore group_rwsem;
621 #endif
622 
623 	oom_flags_t oom_flags;
624 	short oom_score_adj;		/* OOM kill score adjustment */
625 	short oom_score_adj_min;	/* OOM kill score adjustment min value.
626 					 * Only settable by CAP_SYS_RESOURCE. */
627 
628 	struct mutex cred_guard_mutex;	/* guard against foreign influences on
629 					 * credential calculations
630 					 * (notably. ptrace) */
631 };
632 
633 /*
634  * Bits in flags field of signal_struct.
635  */
636 #define SIGNAL_STOP_STOPPED	0x00000001 /* job control stop in effect */
637 #define SIGNAL_STOP_CONTINUED	0x00000002 /* SIGCONT since WCONTINUED reap */
638 #define SIGNAL_GROUP_EXIT	0x00000004 /* group exit in progress */
639 #define SIGNAL_GROUP_COREDUMP	0x00000008 /* coredump in progress */
640 /*
641  * Pending notifications to parent.
642  */
643 #define SIGNAL_CLD_STOPPED	0x00000010
644 #define SIGNAL_CLD_CONTINUED	0x00000020
645 #define SIGNAL_CLD_MASK		(SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
646 
647 #define SIGNAL_UNKILLABLE	0x00000040 /* for init: ignore fatal signals */
648 
649 /* If true, all threads except ->group_exit_task have pending SIGKILL */
650 static inline int signal_group_exit(const struct signal_struct *sig)
651 {
652 	return	(sig->flags & SIGNAL_GROUP_EXIT) ||
653 		(sig->group_exit_task != NULL);
654 }
655 
656 /*
657  * Some day this will be a full-fledged user tracking system..
658  */
659 struct user_struct {
660 	atomic_t __count;	/* reference count */
661 	atomic_t processes;	/* How many processes does this user have? */
662 	atomic_t files;		/* How many open files does this user have? */
663 	atomic_t sigpending;	/* How many pending signals does this user have? */
664 #ifdef CONFIG_INOTIFY_USER
665 	atomic_t inotify_watches; /* How many inotify watches does this user have? */
666 	atomic_t inotify_devs;	/* How many inotify devs does this user have opened? */
667 #endif
668 #ifdef CONFIG_FANOTIFY
669 	atomic_t fanotify_listeners;
670 #endif
671 #ifdef CONFIG_EPOLL
672 	atomic_long_t epoll_watches; /* The number of file descriptors currently watched */
673 #endif
674 #ifdef CONFIG_POSIX_MQUEUE
675 	/* protected by mq_lock	*/
676 	unsigned long mq_bytes;	/* How many bytes can be allocated to mqueue? */
677 #endif
678 	unsigned long locked_shm; /* How many pages of mlocked shm ? */
679 
680 #ifdef CONFIG_KEYS
681 	struct key *uid_keyring;	/* UID specific keyring */
682 	struct key *session_keyring;	/* UID's default session keyring */
683 #endif
684 
685 	/* Hash table maintenance information */
686 	struct hlist_node uidhash_node;
687 	kuid_t uid;
688 
689 #ifdef CONFIG_PERF_EVENTS
690 	atomic_long_t locked_vm;
691 #endif
692 };
693 
694 extern int uids_sysfs_init(void);
695 
696 extern struct user_struct *find_user(kuid_t);
697 
698 extern struct user_struct root_user;
699 #define INIT_USER (&root_user)
700 
701 
702 struct backing_dev_info;
703 struct reclaim_state;
704 
705 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
706 struct sched_info {
707 	/* cumulative counters */
708 	unsigned long pcount;	      /* # of times run on this cpu */
709 	unsigned long long run_delay; /* time spent waiting on a runqueue */
710 
711 	/* timestamps */
712 	unsigned long long last_arrival,/* when we last ran on a cpu */
713 			   last_queued;	/* when we were last queued to run */
714 };
715 #endif /* defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) */
716 
717 #ifdef CONFIG_TASK_DELAY_ACCT
718 struct task_delay_info {
719 	spinlock_t	lock;
720 	unsigned int	flags;	/* Private per-task flags */
721 
722 	/* For each stat XXX, add following, aligned appropriately
723 	 *
724 	 * struct timespec XXX_start, XXX_end;
725 	 * u64 XXX_delay;
726 	 * u32 XXX_count;
727 	 *
728 	 * Atomicity of updates to XXX_delay, XXX_count protected by
729 	 * single lock above (split into XXX_lock if contention is an issue).
730 	 */
731 
732 	/*
733 	 * XXX_count is incremented on every XXX operation, the delay
734 	 * associated with the operation is added to XXX_delay.
735 	 * XXX_delay contains the accumulated delay time in nanoseconds.
736 	 */
737 	struct timespec blkio_start, blkio_end;	/* Shared by blkio, swapin */
738 	u64 blkio_delay;	/* wait for sync block io completion */
739 	u64 swapin_delay;	/* wait for swapin block io completion */
740 	u32 blkio_count;	/* total count of the number of sync block */
741 				/* io operations performed */
742 	u32 swapin_count;	/* total count of the number of swapin block */
743 				/* io operations performed */
744 
745 	struct timespec freepages_start, freepages_end;
746 	u64 freepages_delay;	/* wait for memory reclaim */
747 	u32 freepages_count;	/* total count of memory reclaim */
748 };
749 #endif	/* CONFIG_TASK_DELAY_ACCT */
750 
751 static inline int sched_info_on(void)
752 {
753 #ifdef CONFIG_SCHEDSTATS
754 	return 1;
755 #elif defined(CONFIG_TASK_DELAY_ACCT)
756 	extern int delayacct_on;
757 	return delayacct_on;
758 #else
759 	return 0;
760 #endif
761 }
762 
763 enum cpu_idle_type {
764 	CPU_IDLE,
765 	CPU_NOT_IDLE,
766 	CPU_NEWLY_IDLE,
767 	CPU_MAX_IDLE_TYPES
768 };
769 
770 /*
771  * Increase resolution of cpu_power calculations
772  */
773 #define SCHED_POWER_SHIFT	10
774 #define SCHED_POWER_SCALE	(1L << SCHED_POWER_SHIFT)
775 
776 /*
777  * sched-domains (multiprocessor balancing) declarations:
778  */
779 #ifdef CONFIG_SMP
780 #define SD_LOAD_BALANCE		0x0001	/* Do load balancing on this domain. */
781 #define SD_BALANCE_NEWIDLE	0x0002	/* Balance when about to become idle */
782 #define SD_BALANCE_EXEC		0x0004	/* Balance on exec */
783 #define SD_BALANCE_FORK		0x0008	/* Balance on fork, clone */
784 #define SD_BALANCE_WAKE		0x0010  /* Balance on wakeup */
785 #define SD_WAKE_AFFINE		0x0020	/* Wake task to waking CPU */
786 #define SD_SHARE_CPUPOWER	0x0080	/* Domain members share cpu power */
787 #define SD_SHARE_PKG_RESOURCES	0x0200	/* Domain members share cpu pkg resources */
788 #define SD_SERIALIZE		0x0400	/* Only a single load balancing instance */
789 #define SD_ASYM_PACKING		0x0800  /* Place busy groups earlier in the domain */
790 #define SD_PREFER_SIBLING	0x1000	/* Prefer to place tasks in a sibling domain */
791 #define SD_OVERLAP		0x2000	/* sched_domains of this level overlap */
792 #define SD_NUMA			0x4000	/* cross-node balancing */
793 
794 extern int __weak arch_sd_sibiling_asym_packing(void);
795 
796 struct sched_domain_attr {
797 	int relax_domain_level;
798 };
799 
800 #define SD_ATTR_INIT	(struct sched_domain_attr) {	\
801 	.relax_domain_level = -1,			\
802 }
803 
804 extern int sched_domain_level_max;
805 
806 struct sched_group;
807 
808 struct sched_domain {
809 	/* These fields must be setup */
810 	struct sched_domain *parent;	/* top domain must be null terminated */
811 	struct sched_domain *child;	/* bottom domain must be null terminated */
812 	struct sched_group *groups;	/* the balancing groups of the domain */
813 	unsigned long min_interval;	/* Minimum balance interval ms */
814 	unsigned long max_interval;	/* Maximum balance interval ms */
815 	unsigned int busy_factor;	/* less balancing by factor if busy */
816 	unsigned int imbalance_pct;	/* No balance until over watermark */
817 	unsigned int cache_nice_tries;	/* Leave cache hot tasks for # tries */
818 	unsigned int busy_idx;
819 	unsigned int idle_idx;
820 	unsigned int newidle_idx;
821 	unsigned int wake_idx;
822 	unsigned int forkexec_idx;
823 	unsigned int smt_gain;
824 
825 	int nohz_idle;			/* NOHZ IDLE status */
826 	int flags;			/* See SD_* */
827 	int level;
828 
829 	/* Runtime fields. */
830 	unsigned long last_balance;	/* init to jiffies. units in jiffies */
831 	unsigned int balance_interval;	/* initialise to 1. units in ms. */
832 	unsigned int nr_balance_failed; /* initialise to 0 */
833 
834 	u64 last_update;
835 
836 	/* idle_balance() stats */
837 	u64 max_newidle_lb_cost;
838 	unsigned long next_decay_max_lb_cost;
839 
840 #ifdef CONFIG_SCHEDSTATS
841 	/* load_balance() stats */
842 	unsigned int lb_count[CPU_MAX_IDLE_TYPES];
843 	unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
844 	unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
845 	unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
846 	unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
847 	unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
848 	unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
849 	unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
850 
851 	/* Active load balancing */
852 	unsigned int alb_count;
853 	unsigned int alb_failed;
854 	unsigned int alb_pushed;
855 
856 	/* SD_BALANCE_EXEC stats */
857 	unsigned int sbe_count;
858 	unsigned int sbe_balanced;
859 	unsigned int sbe_pushed;
860 
861 	/* SD_BALANCE_FORK stats */
862 	unsigned int sbf_count;
863 	unsigned int sbf_balanced;
864 	unsigned int sbf_pushed;
865 
866 	/* try_to_wake_up() stats */
867 	unsigned int ttwu_wake_remote;
868 	unsigned int ttwu_move_affine;
869 	unsigned int ttwu_move_balance;
870 #endif
871 #ifdef CONFIG_SCHED_DEBUG
872 	char *name;
873 #endif
874 	union {
875 		void *private;		/* used during construction */
876 		struct rcu_head rcu;	/* used during destruction */
877 	};
878 
879 	unsigned int span_weight;
880 	/*
881 	 * Span of all CPUs in this domain.
882 	 *
883 	 * NOTE: this field is variable length. (Allocated dynamically
884 	 * by attaching extra space to the end of the structure,
885 	 * depending on how many CPUs the kernel has booted up with)
886 	 */
887 	unsigned long span[0];
888 };
889 
890 static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
891 {
892 	return to_cpumask(sd->span);
893 }
894 
895 extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
896 				    struct sched_domain_attr *dattr_new);
897 
898 /* Allocate an array of sched domains, for partition_sched_domains(). */
899 cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
900 void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
901 
902 bool cpus_share_cache(int this_cpu, int that_cpu);
903 
904 #else /* CONFIG_SMP */
905 
906 struct sched_domain_attr;
907 
908 static inline void
909 partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
910 			struct sched_domain_attr *dattr_new)
911 {
912 }
913 
914 static inline bool cpus_share_cache(int this_cpu, int that_cpu)
915 {
916 	return true;
917 }
918 
919 #endif	/* !CONFIG_SMP */
920 
921 
922 struct io_context;			/* See blkdev.h */
923 
924 
925 #ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
926 extern void prefetch_stack(struct task_struct *t);
927 #else
928 static inline void prefetch_stack(struct task_struct *t) { }
929 #endif
930 
931 struct audit_context;		/* See audit.c */
932 struct mempolicy;
933 struct pipe_inode_info;
934 struct uts_namespace;
935 
936 struct load_weight {
937 	unsigned long weight, inv_weight;
938 };
939 
940 struct sched_avg {
941 	/*
942 	 * These sums represent an infinite geometric series and so are bound
943 	 * above by 1024/(1-y).  Thus we only need a u32 to store them for all
944 	 * choices of y < 1-2^(-32)*1024.
945 	 */
946 	u32 runnable_avg_sum, runnable_avg_period;
947 	u64 last_runnable_update;
948 	s64 decay_count;
949 	unsigned long load_avg_contrib;
950 };
951 
952 #ifdef CONFIG_SCHEDSTATS
953 struct sched_statistics {
954 	u64			wait_start;
955 	u64			wait_max;
956 	u64			wait_count;
957 	u64			wait_sum;
958 	u64			iowait_count;
959 	u64			iowait_sum;
960 
961 	u64			sleep_start;
962 	u64			sleep_max;
963 	s64			sum_sleep_runtime;
964 
965 	u64			block_start;
966 	u64			block_max;
967 	u64			exec_max;
968 	u64			slice_max;
969 
970 	u64			nr_migrations_cold;
971 	u64			nr_failed_migrations_affine;
972 	u64			nr_failed_migrations_running;
973 	u64			nr_failed_migrations_hot;
974 	u64			nr_forced_migrations;
975 
976 	u64			nr_wakeups;
977 	u64			nr_wakeups_sync;
978 	u64			nr_wakeups_migrate;
979 	u64			nr_wakeups_local;
980 	u64			nr_wakeups_remote;
981 	u64			nr_wakeups_affine;
982 	u64			nr_wakeups_affine_attempts;
983 	u64			nr_wakeups_passive;
984 	u64			nr_wakeups_idle;
985 };
986 #endif
987 
988 struct sched_entity {
989 	struct load_weight	load;		/* for load-balancing */
990 	struct rb_node		run_node;
991 	struct list_head	group_node;
992 	unsigned int		on_rq;
993 
994 	u64			exec_start;
995 	u64			sum_exec_runtime;
996 	u64			vruntime;
997 	u64			prev_sum_exec_runtime;
998 
999 	u64			nr_migrations;
1000 
1001 #ifdef CONFIG_SCHEDSTATS
1002 	struct sched_statistics statistics;
1003 #endif
1004 
1005 #ifdef CONFIG_FAIR_GROUP_SCHED
1006 	struct sched_entity	*parent;
1007 	/* rq on which this entity is (to be) queued: */
1008 	struct cfs_rq		*cfs_rq;
1009 	/* rq "owned" by this entity/group: */
1010 	struct cfs_rq		*my_q;
1011 #endif
1012 
1013 #ifdef CONFIG_SMP
1014 	/* Per-entity load-tracking */
1015 	struct sched_avg	avg;
1016 #endif
1017 };
1018 
1019 struct sched_rt_entity {
1020 	struct list_head run_list;
1021 	unsigned long timeout;
1022 	unsigned long watchdog_stamp;
1023 	unsigned int time_slice;
1024 
1025 	struct sched_rt_entity *back;
1026 #ifdef CONFIG_RT_GROUP_SCHED
1027 	struct sched_rt_entity	*parent;
1028 	/* rq on which this entity is (to be) queued: */
1029 	struct rt_rq		*rt_rq;
1030 	/* rq "owned" by this entity/group: */
1031 	struct rt_rq		*my_q;
1032 #endif
1033 };
1034 
1035 
1036 struct rcu_node;
1037 
1038 enum perf_event_task_context {
1039 	perf_invalid_context = -1,
1040 	perf_hw_context = 0,
1041 	perf_sw_context,
1042 	perf_nr_task_contexts,
1043 };
1044 
1045 struct task_struct {
1046 	volatile long state;	/* -1 unrunnable, 0 runnable, >0 stopped */
1047 	void *stack;
1048 	atomic_t usage;
1049 	unsigned int flags;	/* per process flags, defined below */
1050 	unsigned int ptrace;
1051 
1052 #ifdef CONFIG_SMP
1053 	struct llist_node wake_entry;
1054 	int on_cpu;
1055 	struct task_struct *last_wakee;
1056 	unsigned long wakee_flips;
1057 	unsigned long wakee_flip_decay_ts;
1058 
1059 	int wake_cpu;
1060 #endif
1061 	int on_rq;
1062 
1063 	int prio, static_prio, normal_prio;
1064 	unsigned int rt_priority;
1065 	const struct sched_class *sched_class;
1066 	struct sched_entity se;
1067 	struct sched_rt_entity rt;
1068 #ifdef CONFIG_CGROUP_SCHED
1069 	struct task_group *sched_task_group;
1070 #endif
1071 
1072 #ifdef CONFIG_PREEMPT_NOTIFIERS
1073 	/* list of struct preempt_notifier: */
1074 	struct hlist_head preempt_notifiers;
1075 #endif
1076 
1077 #ifdef CONFIG_BLK_DEV_IO_TRACE
1078 	unsigned int btrace_seq;
1079 #endif
1080 
1081 	unsigned int policy;
1082 	int nr_cpus_allowed;
1083 	cpumask_t cpus_allowed;
1084 
1085 #ifdef CONFIG_PREEMPT_RCU
1086 	int rcu_read_lock_nesting;
1087 	char rcu_read_unlock_special;
1088 	struct list_head rcu_node_entry;
1089 #endif /* #ifdef CONFIG_PREEMPT_RCU */
1090 #ifdef CONFIG_TREE_PREEMPT_RCU
1091 	struct rcu_node *rcu_blocked_node;
1092 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
1093 #ifdef CONFIG_RCU_BOOST
1094 	struct rt_mutex *rcu_boost_mutex;
1095 #endif /* #ifdef CONFIG_RCU_BOOST */
1096 
1097 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
1098 	struct sched_info sched_info;
1099 #endif
1100 
1101 	struct list_head tasks;
1102 #ifdef CONFIG_SMP
1103 	struct plist_node pushable_tasks;
1104 #endif
1105 
1106 	struct mm_struct *mm, *active_mm;
1107 #ifdef CONFIG_COMPAT_BRK
1108 	unsigned brk_randomized:1;
1109 #endif
1110 #if defined(SPLIT_RSS_COUNTING)
1111 	struct task_rss_stat	rss_stat;
1112 #endif
1113 /* task state */
1114 	int exit_state;
1115 	int exit_code, exit_signal;
1116 	int pdeath_signal;  /*  The signal sent when the parent dies  */
1117 	unsigned int jobctl;	/* JOBCTL_*, siglock protected */
1118 
1119 	/* Used for emulating ABI behavior of previous Linux versions */
1120 	unsigned int personality;
1121 
1122 	unsigned did_exec:1;
1123 	unsigned in_execve:1;	/* Tell the LSMs that the process is doing an
1124 				 * execve */
1125 	unsigned in_iowait:1;
1126 
1127 	/* task may not gain privileges */
1128 	unsigned no_new_privs:1;
1129 
1130 	/* Revert to default priority/policy when forking */
1131 	unsigned sched_reset_on_fork:1;
1132 	unsigned sched_contributes_to_load:1;
1133 
1134 	pid_t pid;
1135 	pid_t tgid;
1136 
1137 #ifdef CONFIG_CC_STACKPROTECTOR
1138 	/* Canary value for the -fstack-protector gcc feature */
1139 	unsigned long stack_canary;
1140 #endif
1141 	/*
1142 	 * pointers to (original) parent process, youngest child, younger sibling,
1143 	 * older sibling, respectively.  (p->father can be replaced with
1144 	 * p->real_parent->pid)
1145 	 */
1146 	struct task_struct __rcu *real_parent; /* real parent process */
1147 	struct task_struct __rcu *parent; /* recipient of SIGCHLD, wait4() reports */
1148 	/*
1149 	 * children/sibling forms the list of my natural children
1150 	 */
1151 	struct list_head children;	/* list of my children */
1152 	struct list_head sibling;	/* linkage in my parent's children list */
1153 	struct task_struct *group_leader;	/* threadgroup leader */
1154 
1155 	/*
1156 	 * ptraced is the list of tasks this task is using ptrace on.
1157 	 * This includes both natural children and PTRACE_ATTACH targets.
1158 	 * p->ptrace_entry is p's link on the p->parent->ptraced list.
1159 	 */
1160 	struct list_head ptraced;
1161 	struct list_head ptrace_entry;
1162 
1163 	/* PID/PID hash table linkage. */
1164 	struct pid_link pids[PIDTYPE_MAX];
1165 	struct list_head thread_group;
1166 
1167 	struct completion *vfork_done;		/* for vfork() */
1168 	int __user *set_child_tid;		/* CLONE_CHILD_SETTID */
1169 	int __user *clear_child_tid;		/* CLONE_CHILD_CLEARTID */
1170 
1171 	cputime_t utime, stime, utimescaled, stimescaled;
1172 	cputime_t gtime;
1173 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
1174 	struct cputime prev_cputime;
1175 #endif
1176 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1177 	seqlock_t vtime_seqlock;
1178 	unsigned long long vtime_snap;
1179 	enum {
1180 		VTIME_SLEEPING = 0,
1181 		VTIME_USER,
1182 		VTIME_SYS,
1183 	} vtime_snap_whence;
1184 #endif
1185 	unsigned long nvcsw, nivcsw; /* context switch counts */
1186 	struct timespec start_time; 		/* monotonic time */
1187 	struct timespec real_start_time;	/* boot based time */
1188 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1189 	unsigned long min_flt, maj_flt;
1190 
1191 	struct task_cputime cputime_expires;
1192 	struct list_head cpu_timers[3];
1193 
1194 /* process credentials */
1195 	const struct cred __rcu *real_cred; /* objective and real subjective task
1196 					 * credentials (COW) */
1197 	const struct cred __rcu *cred;	/* effective (overridable) subjective task
1198 					 * credentials (COW) */
1199 	char comm[TASK_COMM_LEN]; /* executable name excluding path
1200 				     - access with [gs]et_task_comm (which lock
1201 				       it with task_lock())
1202 				     - initialized normally by setup_new_exec */
1203 /* file system info */
1204 	int link_count, total_link_count;
1205 #ifdef CONFIG_SYSVIPC
1206 /* ipc stuff */
1207 	struct sysv_sem sysvsem;
1208 #endif
1209 #ifdef CONFIG_DETECT_HUNG_TASK
1210 /* hung task detection */
1211 	unsigned long last_switch_count;
1212 #endif
1213 /* CPU-specific state of this task */
1214 	struct thread_struct thread;
1215 /* filesystem information */
1216 	struct fs_struct *fs;
1217 /* open file information */
1218 	struct files_struct *files;
1219 /* namespaces */
1220 	struct nsproxy *nsproxy;
1221 /* signal handlers */
1222 	struct signal_struct *signal;
1223 	struct sighand_struct *sighand;
1224 
1225 	sigset_t blocked, real_blocked;
1226 	sigset_t saved_sigmask;	/* restored if set_restore_sigmask() was used */
1227 	struct sigpending pending;
1228 
1229 	unsigned long sas_ss_sp;
1230 	size_t sas_ss_size;
1231 	int (*notifier)(void *priv);
1232 	void *notifier_data;
1233 	sigset_t *notifier_mask;
1234 	struct callback_head *task_works;
1235 
1236 	struct audit_context *audit_context;
1237 #ifdef CONFIG_AUDITSYSCALL
1238 	kuid_t loginuid;
1239 	unsigned int sessionid;
1240 #endif
1241 	struct seccomp seccomp;
1242 
1243 /* Thread group tracking */
1244    	u32 parent_exec_id;
1245    	u32 self_exec_id;
1246 /* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1247  * mempolicy */
1248 	spinlock_t alloc_lock;
1249 
1250 	/* Protection of the PI data structures: */
1251 	raw_spinlock_t pi_lock;
1252 
1253 #ifdef CONFIG_RT_MUTEXES
1254 	/* PI waiters blocked on a rt_mutex held by this task */
1255 	struct plist_head pi_waiters;
1256 	/* Deadlock detection and priority inheritance handling */
1257 	struct rt_mutex_waiter *pi_blocked_on;
1258 #endif
1259 
1260 #ifdef CONFIG_DEBUG_MUTEXES
1261 	/* mutex deadlock detection */
1262 	struct mutex_waiter *blocked_on;
1263 #endif
1264 #ifdef CONFIG_TRACE_IRQFLAGS
1265 	unsigned int irq_events;
1266 	unsigned long hardirq_enable_ip;
1267 	unsigned long hardirq_disable_ip;
1268 	unsigned int hardirq_enable_event;
1269 	unsigned int hardirq_disable_event;
1270 	int hardirqs_enabled;
1271 	int hardirq_context;
1272 	unsigned long softirq_disable_ip;
1273 	unsigned long softirq_enable_ip;
1274 	unsigned int softirq_disable_event;
1275 	unsigned int softirq_enable_event;
1276 	int softirqs_enabled;
1277 	int softirq_context;
1278 #endif
1279 #ifdef CONFIG_LOCKDEP
1280 # define MAX_LOCK_DEPTH 48UL
1281 	u64 curr_chain_key;
1282 	int lockdep_depth;
1283 	unsigned int lockdep_recursion;
1284 	struct held_lock held_locks[MAX_LOCK_DEPTH];
1285 	gfp_t lockdep_reclaim_gfp;
1286 #endif
1287 
1288 /* journalling filesystem info */
1289 	void *journal_info;
1290 
1291 /* stacked block device info */
1292 	struct bio_list *bio_list;
1293 
1294 #ifdef CONFIG_BLOCK
1295 /* stack plugging */
1296 	struct blk_plug *plug;
1297 #endif
1298 
1299 /* VM state */
1300 	struct reclaim_state *reclaim_state;
1301 
1302 	struct backing_dev_info *backing_dev_info;
1303 
1304 	struct io_context *io_context;
1305 
1306 	unsigned long ptrace_message;
1307 	siginfo_t *last_siginfo; /* For ptrace use.  */
1308 	struct task_io_accounting ioac;
1309 #if defined(CONFIG_TASK_XACCT)
1310 	u64 acct_rss_mem1;	/* accumulated rss usage */
1311 	u64 acct_vm_mem1;	/* accumulated virtual memory usage */
1312 	cputime_t acct_timexpd;	/* stime + utime since last update */
1313 #endif
1314 #ifdef CONFIG_CPUSETS
1315 	nodemask_t mems_allowed;	/* Protected by alloc_lock */
1316 	seqcount_t mems_allowed_seq;	/* Seqence no to catch updates */
1317 	int cpuset_mem_spread_rotor;
1318 	int cpuset_slab_spread_rotor;
1319 #endif
1320 #ifdef CONFIG_CGROUPS
1321 	/* Control Group info protected by css_set_lock */
1322 	struct css_set __rcu *cgroups;
1323 	/* cg_list protected by css_set_lock and tsk->alloc_lock */
1324 	struct list_head cg_list;
1325 #endif
1326 #ifdef CONFIG_FUTEX
1327 	struct robust_list_head __user *robust_list;
1328 #ifdef CONFIG_COMPAT
1329 	struct compat_robust_list_head __user *compat_robust_list;
1330 #endif
1331 	struct list_head pi_state_list;
1332 	struct futex_pi_state *pi_state_cache;
1333 #endif
1334 #ifdef CONFIG_PERF_EVENTS
1335 	struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1336 	struct mutex perf_event_mutex;
1337 	struct list_head perf_event_list;
1338 #endif
1339 #ifdef CONFIG_NUMA
1340 	struct mempolicy *mempolicy;	/* Protected by alloc_lock */
1341 	short il_next;
1342 	short pref_node_fork;
1343 #endif
1344 #ifdef CONFIG_NUMA_BALANCING
1345 	int numa_scan_seq;
1346 	unsigned int numa_scan_period;
1347 	unsigned int numa_scan_period_max;
1348 	int numa_preferred_nid;
1349 	int numa_migrate_deferred;
1350 	unsigned long numa_migrate_retry;
1351 	u64 node_stamp;			/* migration stamp  */
1352 	struct callback_head numa_work;
1353 
1354 	struct list_head numa_entry;
1355 	struct numa_group *numa_group;
1356 
1357 	/*
1358 	 * Exponential decaying average of faults on a per-node basis.
1359 	 * Scheduling placement decisions are made based on the these counts.
1360 	 * The values remain static for the duration of a PTE scan
1361 	 */
1362 	unsigned long *numa_faults;
1363 	unsigned long total_numa_faults;
1364 
1365 	/*
1366 	 * numa_faults_buffer records faults per node during the current
1367 	 * scan window. When the scan completes, the counts in numa_faults
1368 	 * decay and these values are copied.
1369 	 */
1370 	unsigned long *numa_faults_buffer;
1371 
1372 	/*
1373 	 * numa_faults_locality tracks if faults recorded during the last
1374 	 * scan window were remote/local. The task scan period is adapted
1375 	 * based on the locality of the faults with different weights
1376 	 * depending on whether they were shared or private faults
1377 	 */
1378 	unsigned long numa_faults_locality[2];
1379 
1380 	unsigned long numa_pages_migrated;
1381 #endif /* CONFIG_NUMA_BALANCING */
1382 
1383 	struct rcu_head rcu;
1384 
1385 	/*
1386 	 * cache last used pipe for splice
1387 	 */
1388 	struct pipe_inode_info *splice_pipe;
1389 
1390 	struct page_frag task_frag;
1391 
1392 #ifdef	CONFIG_TASK_DELAY_ACCT
1393 	struct task_delay_info *delays;
1394 #endif
1395 #ifdef CONFIG_FAULT_INJECTION
1396 	int make_it_fail;
1397 #endif
1398 	/*
1399 	 * when (nr_dirtied >= nr_dirtied_pause), it's time to call
1400 	 * balance_dirty_pages() for some dirty throttling pause
1401 	 */
1402 	int nr_dirtied;
1403 	int nr_dirtied_pause;
1404 	unsigned long dirty_paused_when; /* start of a write-and-pause period */
1405 
1406 #ifdef CONFIG_LATENCYTOP
1407 	int latency_record_count;
1408 	struct latency_record latency_record[LT_SAVECOUNT];
1409 #endif
1410 	/*
1411 	 * time slack values; these are used to round up poll() and
1412 	 * select() etc timeout values. These are in nanoseconds.
1413 	 */
1414 	unsigned long timer_slack_ns;
1415 	unsigned long default_timer_slack_ns;
1416 
1417 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1418 	/* Index of current stored address in ret_stack */
1419 	int curr_ret_stack;
1420 	/* Stack of return addresses for return function tracing */
1421 	struct ftrace_ret_stack	*ret_stack;
1422 	/* time stamp for last schedule */
1423 	unsigned long long ftrace_timestamp;
1424 	/*
1425 	 * Number of functions that haven't been traced
1426 	 * because of depth overrun.
1427 	 */
1428 	atomic_t trace_overrun;
1429 	/* Pause for the tracing */
1430 	atomic_t tracing_graph_pause;
1431 #endif
1432 #ifdef CONFIG_TRACING
1433 	/* state flags for use by tracers */
1434 	unsigned long trace;
1435 	/* bitmask and counter of trace recursion */
1436 	unsigned long trace_recursion;
1437 #endif /* CONFIG_TRACING */
1438 #ifdef CONFIG_MEMCG /* memcg uses this to do batch job */
1439 	struct memcg_batch_info {
1440 		int do_batch;	/* incremented when batch uncharge started */
1441 		struct mem_cgroup *memcg; /* target memcg of uncharge */
1442 		unsigned long nr_pages;	/* uncharged usage */
1443 		unsigned long memsw_nr_pages; /* uncharged mem+swap usage */
1444 	} memcg_batch;
1445 	unsigned int memcg_kmem_skip_account;
1446 	struct memcg_oom_info {
1447 		struct mem_cgroup *memcg;
1448 		gfp_t gfp_mask;
1449 		int order;
1450 		unsigned int may_oom:1;
1451 	} memcg_oom;
1452 #endif
1453 #ifdef CONFIG_UPROBES
1454 	struct uprobe_task *utask;
1455 #endif
1456 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1457 	unsigned int	sequential_io;
1458 	unsigned int	sequential_io_avg;
1459 #endif
1460 };
1461 
1462 /* Future-safe accessor for struct task_struct's cpus_allowed. */
1463 #define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
1464 
1465 #define TNF_MIGRATED	0x01
1466 #define TNF_NO_GROUP	0x02
1467 #define TNF_SHARED	0x04
1468 #define TNF_FAULT_LOCAL	0x08
1469 
1470 #ifdef CONFIG_NUMA_BALANCING
1471 extern void task_numa_fault(int last_node, int node, int pages, int flags);
1472 extern pid_t task_numa_group_id(struct task_struct *p);
1473 extern void set_numabalancing_state(bool enabled);
1474 extern void task_numa_free(struct task_struct *p);
1475 
1476 extern unsigned int sysctl_numa_balancing_migrate_deferred;
1477 #else
1478 static inline void task_numa_fault(int last_node, int node, int pages,
1479 				   int flags)
1480 {
1481 }
1482 static inline pid_t task_numa_group_id(struct task_struct *p)
1483 {
1484 	return 0;
1485 }
1486 static inline void set_numabalancing_state(bool enabled)
1487 {
1488 }
1489 static inline void task_numa_free(struct task_struct *p)
1490 {
1491 }
1492 #endif
1493 
1494 static inline struct pid *task_pid(struct task_struct *task)
1495 {
1496 	return task->pids[PIDTYPE_PID].pid;
1497 }
1498 
1499 static inline struct pid *task_tgid(struct task_struct *task)
1500 {
1501 	return task->group_leader->pids[PIDTYPE_PID].pid;
1502 }
1503 
1504 /*
1505  * Without tasklist or rcu lock it is not safe to dereference
1506  * the result of task_pgrp/task_session even if task == current,
1507  * we can race with another thread doing sys_setsid/sys_setpgid.
1508  */
1509 static inline struct pid *task_pgrp(struct task_struct *task)
1510 {
1511 	return task->group_leader->pids[PIDTYPE_PGID].pid;
1512 }
1513 
1514 static inline struct pid *task_session(struct task_struct *task)
1515 {
1516 	return task->group_leader->pids[PIDTYPE_SID].pid;
1517 }
1518 
1519 struct pid_namespace;
1520 
1521 /*
1522  * the helpers to get the task's different pids as they are seen
1523  * from various namespaces
1524  *
1525  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1526  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1527  *                     current.
1528  * task_xid_nr_ns()  : id seen from the ns specified;
1529  *
1530  * set_task_vxid()   : assigns a virtual id to a task;
1531  *
1532  * see also pid_nr() etc in include/linux/pid.h
1533  */
1534 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
1535 			struct pid_namespace *ns);
1536 
1537 static inline pid_t task_pid_nr(struct task_struct *tsk)
1538 {
1539 	return tsk->pid;
1540 }
1541 
1542 static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
1543 					struct pid_namespace *ns)
1544 {
1545 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1546 }
1547 
1548 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1549 {
1550 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1551 }
1552 
1553 
1554 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1555 {
1556 	return tsk->tgid;
1557 }
1558 
1559 pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1560 
1561 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1562 {
1563 	return pid_vnr(task_tgid(tsk));
1564 }
1565 
1566 
1567 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
1568 					struct pid_namespace *ns)
1569 {
1570 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1571 }
1572 
1573 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1574 {
1575 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1576 }
1577 
1578 
1579 static inline pid_t task_session_nr_ns(struct task_struct *tsk,
1580 					struct pid_namespace *ns)
1581 {
1582 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1583 }
1584 
1585 static inline pid_t task_session_vnr(struct task_struct *tsk)
1586 {
1587 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1588 }
1589 
1590 /* obsolete, do not use */
1591 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1592 {
1593 	return task_pgrp_nr_ns(tsk, &init_pid_ns);
1594 }
1595 
1596 /**
1597  * pid_alive - check that a task structure is not stale
1598  * @p: Task structure to be checked.
1599  *
1600  * Test if a process is not yet dead (at most zombie state)
1601  * If pid_alive fails, then pointers within the task structure
1602  * can be stale and must not be dereferenced.
1603  *
1604  * Return: 1 if the process is alive. 0 otherwise.
1605  */
1606 static inline int pid_alive(struct task_struct *p)
1607 {
1608 	return p->pids[PIDTYPE_PID].pid != NULL;
1609 }
1610 
1611 /**
1612  * is_global_init - check if a task structure is init
1613  * @tsk: Task structure to be checked.
1614  *
1615  * Check if a task structure is the first user space task the kernel created.
1616  *
1617  * Return: 1 if the task structure is init. 0 otherwise.
1618  */
1619 static inline int is_global_init(struct task_struct *tsk)
1620 {
1621 	return tsk->pid == 1;
1622 }
1623 
1624 extern struct pid *cad_pid;
1625 
1626 extern void free_task(struct task_struct *tsk);
1627 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
1628 
1629 extern void __put_task_struct(struct task_struct *t);
1630 
1631 static inline void put_task_struct(struct task_struct *t)
1632 {
1633 	if (atomic_dec_and_test(&t->usage))
1634 		__put_task_struct(t);
1635 }
1636 
1637 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1638 extern void task_cputime(struct task_struct *t,
1639 			 cputime_t *utime, cputime_t *stime);
1640 extern void task_cputime_scaled(struct task_struct *t,
1641 				cputime_t *utimescaled, cputime_t *stimescaled);
1642 extern cputime_t task_gtime(struct task_struct *t);
1643 #else
1644 static inline void task_cputime(struct task_struct *t,
1645 				cputime_t *utime, cputime_t *stime)
1646 {
1647 	if (utime)
1648 		*utime = t->utime;
1649 	if (stime)
1650 		*stime = t->stime;
1651 }
1652 
1653 static inline void task_cputime_scaled(struct task_struct *t,
1654 				       cputime_t *utimescaled,
1655 				       cputime_t *stimescaled)
1656 {
1657 	if (utimescaled)
1658 		*utimescaled = t->utimescaled;
1659 	if (stimescaled)
1660 		*stimescaled = t->stimescaled;
1661 }
1662 
1663 static inline cputime_t task_gtime(struct task_struct *t)
1664 {
1665 	return t->gtime;
1666 }
1667 #endif
1668 extern void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
1669 extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
1670 
1671 /*
1672  * Per process flags
1673  */
1674 #define PF_EXITING	0x00000004	/* getting shut down */
1675 #define PF_EXITPIDONE	0x00000008	/* pi exit done on shut down */
1676 #define PF_VCPU		0x00000010	/* I'm a virtual CPU */
1677 #define PF_WQ_WORKER	0x00000020	/* I'm a workqueue worker */
1678 #define PF_FORKNOEXEC	0x00000040	/* forked but didn't exec */
1679 #define PF_MCE_PROCESS  0x00000080      /* process policy on mce errors */
1680 #define PF_SUPERPRIV	0x00000100	/* used super-user privileges */
1681 #define PF_DUMPCORE	0x00000200	/* dumped core */
1682 #define PF_SIGNALED	0x00000400	/* killed by a signal */
1683 #define PF_MEMALLOC	0x00000800	/* Allocating memory */
1684 #define PF_NPROC_EXCEEDED 0x00001000	/* set_user noticed that RLIMIT_NPROC was exceeded */
1685 #define PF_USED_MATH	0x00002000	/* if unset the fpu must be initialized before use */
1686 #define PF_USED_ASYNC	0x00004000	/* used async_schedule*(), used by module init */
1687 #define PF_NOFREEZE	0x00008000	/* this thread should not be frozen */
1688 #define PF_FROZEN	0x00010000	/* frozen for system suspend */
1689 #define PF_FSTRANS	0x00020000	/* inside a filesystem transaction */
1690 #define PF_KSWAPD	0x00040000	/* I am kswapd */
1691 #define PF_MEMALLOC_NOIO 0x00080000	/* Allocating memory without IO involved */
1692 #define PF_LESS_THROTTLE 0x00100000	/* Throttle me less: I clean memory */
1693 #define PF_KTHREAD	0x00200000	/* I am a kernel thread */
1694 #define PF_RANDOMIZE	0x00400000	/* randomize virtual address space */
1695 #define PF_SWAPWRITE	0x00800000	/* Allowed to write to swap */
1696 #define PF_SPREAD_PAGE	0x01000000	/* Spread page cache over cpuset */
1697 #define PF_SPREAD_SLAB	0x02000000	/* Spread some slab caches over cpuset */
1698 #define PF_NO_SETAFFINITY 0x04000000	/* Userland is not allowed to meddle with cpus_allowed */
1699 #define PF_MCE_EARLY    0x08000000      /* Early kill for mce process policy */
1700 #define PF_MEMPOLICY	0x10000000	/* Non-default NUMA mempolicy */
1701 #define PF_MUTEX_TESTER	0x20000000	/* Thread belongs to the rt mutex tester */
1702 #define PF_FREEZER_SKIP	0x40000000	/* Freezer should not count it as freezable */
1703 #define PF_SUSPEND_TASK 0x80000000      /* this thread called freeze_processes and should not be frozen */
1704 
1705 /*
1706  * Only the _current_ task can read/write to tsk->flags, but other
1707  * tasks can access tsk->flags in readonly mode for example
1708  * with tsk_used_math (like during threaded core dumping).
1709  * There is however an exception to this rule during ptrace
1710  * or during fork: the ptracer task is allowed to write to the
1711  * child->flags of its traced child (same goes for fork, the parent
1712  * can write to the child->flags), because we're guaranteed the
1713  * child is not running and in turn not changing child->flags
1714  * at the same time the parent does it.
1715  */
1716 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1717 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1718 #define clear_used_math() clear_stopped_child_used_math(current)
1719 #define set_used_math() set_stopped_child_used_math(current)
1720 #define conditional_stopped_child_used_math(condition, child) \
1721 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1722 #define conditional_used_math(condition) \
1723 	conditional_stopped_child_used_math(condition, current)
1724 #define copy_to_stopped_child_used_math(child) \
1725 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1726 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1727 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1728 #define used_math() tsk_used_math(current)
1729 
1730 /* __GFP_IO isn't allowed if PF_MEMALLOC_NOIO is set in current->flags */
1731 static inline gfp_t memalloc_noio_flags(gfp_t flags)
1732 {
1733 	if (unlikely(current->flags & PF_MEMALLOC_NOIO))
1734 		flags &= ~__GFP_IO;
1735 	return flags;
1736 }
1737 
1738 static inline unsigned int memalloc_noio_save(void)
1739 {
1740 	unsigned int flags = current->flags & PF_MEMALLOC_NOIO;
1741 	current->flags |= PF_MEMALLOC_NOIO;
1742 	return flags;
1743 }
1744 
1745 static inline void memalloc_noio_restore(unsigned int flags)
1746 {
1747 	current->flags = (current->flags & ~PF_MEMALLOC_NOIO) | flags;
1748 }
1749 
1750 /*
1751  * task->jobctl flags
1752  */
1753 #define JOBCTL_STOP_SIGMASK	0xffff	/* signr of the last group stop */
1754 
1755 #define JOBCTL_STOP_DEQUEUED_BIT 16	/* stop signal dequeued */
1756 #define JOBCTL_STOP_PENDING_BIT	17	/* task should stop for group stop */
1757 #define JOBCTL_STOP_CONSUME_BIT	18	/* consume group stop count */
1758 #define JOBCTL_TRAP_STOP_BIT	19	/* trap for STOP */
1759 #define JOBCTL_TRAP_NOTIFY_BIT	20	/* trap for NOTIFY */
1760 #define JOBCTL_TRAPPING_BIT	21	/* switching to TRACED */
1761 #define JOBCTL_LISTENING_BIT	22	/* ptracer is listening for events */
1762 
1763 #define JOBCTL_STOP_DEQUEUED	(1 << JOBCTL_STOP_DEQUEUED_BIT)
1764 #define JOBCTL_STOP_PENDING	(1 << JOBCTL_STOP_PENDING_BIT)
1765 #define JOBCTL_STOP_CONSUME	(1 << JOBCTL_STOP_CONSUME_BIT)
1766 #define JOBCTL_TRAP_STOP	(1 << JOBCTL_TRAP_STOP_BIT)
1767 #define JOBCTL_TRAP_NOTIFY	(1 << JOBCTL_TRAP_NOTIFY_BIT)
1768 #define JOBCTL_TRAPPING		(1 << JOBCTL_TRAPPING_BIT)
1769 #define JOBCTL_LISTENING	(1 << JOBCTL_LISTENING_BIT)
1770 
1771 #define JOBCTL_TRAP_MASK	(JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
1772 #define JOBCTL_PENDING_MASK	(JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)
1773 
1774 extern bool task_set_jobctl_pending(struct task_struct *task,
1775 				    unsigned int mask);
1776 extern void task_clear_jobctl_trapping(struct task_struct *task);
1777 extern void task_clear_jobctl_pending(struct task_struct *task,
1778 				      unsigned int mask);
1779 
1780 #ifdef CONFIG_PREEMPT_RCU
1781 
1782 #define RCU_READ_UNLOCK_BLOCKED (1 << 0) /* blocked while in RCU read-side. */
1783 #define RCU_READ_UNLOCK_NEED_QS (1 << 1) /* RCU core needs CPU response. */
1784 
1785 static inline void rcu_copy_process(struct task_struct *p)
1786 {
1787 	p->rcu_read_lock_nesting = 0;
1788 	p->rcu_read_unlock_special = 0;
1789 #ifdef CONFIG_TREE_PREEMPT_RCU
1790 	p->rcu_blocked_node = NULL;
1791 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
1792 #ifdef CONFIG_RCU_BOOST
1793 	p->rcu_boost_mutex = NULL;
1794 #endif /* #ifdef CONFIG_RCU_BOOST */
1795 	INIT_LIST_HEAD(&p->rcu_node_entry);
1796 }
1797 
1798 #else
1799 
1800 static inline void rcu_copy_process(struct task_struct *p)
1801 {
1802 }
1803 
1804 #endif
1805 
1806 static inline void tsk_restore_flags(struct task_struct *task,
1807 				unsigned long orig_flags, unsigned long flags)
1808 {
1809 	task->flags &= ~flags;
1810 	task->flags |= orig_flags & flags;
1811 }
1812 
1813 #ifdef CONFIG_SMP
1814 extern void do_set_cpus_allowed(struct task_struct *p,
1815 			       const struct cpumask *new_mask);
1816 
1817 extern int set_cpus_allowed_ptr(struct task_struct *p,
1818 				const struct cpumask *new_mask);
1819 #else
1820 static inline void do_set_cpus_allowed(struct task_struct *p,
1821 				      const struct cpumask *new_mask)
1822 {
1823 }
1824 static inline int set_cpus_allowed_ptr(struct task_struct *p,
1825 				       const struct cpumask *new_mask)
1826 {
1827 	if (!cpumask_test_cpu(0, new_mask))
1828 		return -EINVAL;
1829 	return 0;
1830 }
1831 #endif
1832 
1833 #ifdef CONFIG_NO_HZ_COMMON
1834 void calc_load_enter_idle(void);
1835 void calc_load_exit_idle(void);
1836 #else
1837 static inline void calc_load_enter_idle(void) { }
1838 static inline void calc_load_exit_idle(void) { }
1839 #endif /* CONFIG_NO_HZ_COMMON */
1840 
1841 #ifndef CONFIG_CPUMASK_OFFSTACK
1842 static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
1843 {
1844 	return set_cpus_allowed_ptr(p, &new_mask);
1845 }
1846 #endif
1847 
1848 /*
1849  * Do not use outside of architecture code which knows its limitations.
1850  *
1851  * sched_clock() has no promise of monotonicity or bounded drift between
1852  * CPUs, use (which you should not) requires disabling IRQs.
1853  *
1854  * Please use one of the three interfaces below.
1855  */
1856 extern unsigned long long notrace sched_clock(void);
1857 /*
1858  * See the comment in kernel/sched/clock.c
1859  */
1860 extern u64 cpu_clock(int cpu);
1861 extern u64 local_clock(void);
1862 extern u64 sched_clock_cpu(int cpu);
1863 
1864 
1865 extern void sched_clock_init(void);
1866 
1867 #ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
1868 static inline void sched_clock_tick(void)
1869 {
1870 }
1871 
1872 static inline void sched_clock_idle_sleep_event(void)
1873 {
1874 }
1875 
1876 static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
1877 {
1878 }
1879 #else
1880 /*
1881  * Architectures can set this to 1 if they have specified
1882  * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
1883  * but then during bootup it turns out that sched_clock()
1884  * is reliable after all:
1885  */
1886 extern int sched_clock_stable;
1887 
1888 extern void sched_clock_tick(void);
1889 extern void sched_clock_idle_sleep_event(void);
1890 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
1891 #endif
1892 
1893 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
1894 /*
1895  * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
1896  * The reason for this explicit opt-in is not to have perf penalty with
1897  * slow sched_clocks.
1898  */
1899 extern void enable_sched_clock_irqtime(void);
1900 extern void disable_sched_clock_irqtime(void);
1901 #else
1902 static inline void enable_sched_clock_irqtime(void) {}
1903 static inline void disable_sched_clock_irqtime(void) {}
1904 #endif
1905 
1906 extern unsigned long long
1907 task_sched_runtime(struct task_struct *task);
1908 
1909 /* sched_exec is called by processes performing an exec */
1910 #ifdef CONFIG_SMP
1911 extern void sched_exec(void);
1912 #else
1913 #define sched_exec()   {}
1914 #endif
1915 
1916 extern void sched_clock_idle_sleep_event(void);
1917 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
1918 
1919 #ifdef CONFIG_HOTPLUG_CPU
1920 extern void idle_task_exit(void);
1921 #else
1922 static inline void idle_task_exit(void) {}
1923 #endif
1924 
1925 #if defined(CONFIG_NO_HZ_COMMON) && defined(CONFIG_SMP)
1926 extern void wake_up_nohz_cpu(int cpu);
1927 #else
1928 static inline void wake_up_nohz_cpu(int cpu) { }
1929 #endif
1930 
1931 #ifdef CONFIG_NO_HZ_FULL
1932 extern bool sched_can_stop_tick(void);
1933 extern u64 scheduler_tick_max_deferment(void);
1934 #else
1935 static inline bool sched_can_stop_tick(void) { return false; }
1936 #endif
1937 
1938 #ifdef CONFIG_SCHED_AUTOGROUP
1939 extern void sched_autogroup_create_attach(struct task_struct *p);
1940 extern void sched_autogroup_detach(struct task_struct *p);
1941 extern void sched_autogroup_fork(struct signal_struct *sig);
1942 extern void sched_autogroup_exit(struct signal_struct *sig);
1943 #ifdef CONFIG_PROC_FS
1944 extern void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m);
1945 extern int proc_sched_autogroup_set_nice(struct task_struct *p, int nice);
1946 #endif
1947 #else
1948 static inline void sched_autogroup_create_attach(struct task_struct *p) { }
1949 static inline void sched_autogroup_detach(struct task_struct *p) { }
1950 static inline void sched_autogroup_fork(struct signal_struct *sig) { }
1951 static inline void sched_autogroup_exit(struct signal_struct *sig) { }
1952 #endif
1953 
1954 extern bool yield_to(struct task_struct *p, bool preempt);
1955 extern void set_user_nice(struct task_struct *p, long nice);
1956 extern int task_prio(const struct task_struct *p);
1957 extern int task_nice(const struct task_struct *p);
1958 extern int can_nice(const struct task_struct *p, const int nice);
1959 extern int task_curr(const struct task_struct *p);
1960 extern int idle_cpu(int cpu);
1961 extern int sched_setscheduler(struct task_struct *, int,
1962 			      const struct sched_param *);
1963 extern int sched_setscheduler_nocheck(struct task_struct *, int,
1964 				      const struct sched_param *);
1965 extern struct task_struct *idle_task(int cpu);
1966 /**
1967  * is_idle_task - is the specified task an idle task?
1968  * @p: the task in question.
1969  *
1970  * Return: 1 if @p is an idle task. 0 otherwise.
1971  */
1972 static inline bool is_idle_task(const struct task_struct *p)
1973 {
1974 	return p->pid == 0;
1975 }
1976 extern struct task_struct *curr_task(int cpu);
1977 extern void set_curr_task(int cpu, struct task_struct *p);
1978 
1979 void yield(void);
1980 
1981 /*
1982  * The default (Linux) execution domain.
1983  */
1984 extern struct exec_domain	default_exec_domain;
1985 
1986 union thread_union {
1987 	struct thread_info thread_info;
1988 	unsigned long stack[THREAD_SIZE/sizeof(long)];
1989 };
1990 
1991 #ifndef __HAVE_ARCH_KSTACK_END
1992 static inline int kstack_end(void *addr)
1993 {
1994 	/* Reliable end of stack detection:
1995 	 * Some APM bios versions misalign the stack
1996 	 */
1997 	return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
1998 }
1999 #endif
2000 
2001 extern union thread_union init_thread_union;
2002 extern struct task_struct init_task;
2003 
2004 extern struct   mm_struct init_mm;
2005 
2006 extern struct pid_namespace init_pid_ns;
2007 
2008 /*
2009  * find a task by one of its numerical ids
2010  *
2011  * find_task_by_pid_ns():
2012  *      finds a task by its pid in the specified namespace
2013  * find_task_by_vpid():
2014  *      finds a task by its virtual pid
2015  *
2016  * see also find_vpid() etc in include/linux/pid.h
2017  */
2018 
2019 extern struct task_struct *find_task_by_vpid(pid_t nr);
2020 extern struct task_struct *find_task_by_pid_ns(pid_t nr,
2021 		struct pid_namespace *ns);
2022 
2023 /* per-UID process charging. */
2024 extern struct user_struct * alloc_uid(kuid_t);
2025 static inline struct user_struct *get_uid(struct user_struct *u)
2026 {
2027 	atomic_inc(&u->__count);
2028 	return u;
2029 }
2030 extern void free_uid(struct user_struct *);
2031 
2032 #include <asm/current.h>
2033 
2034 extern void xtime_update(unsigned long ticks);
2035 
2036 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2037 extern int wake_up_process(struct task_struct *tsk);
2038 extern void wake_up_new_task(struct task_struct *tsk);
2039 #ifdef CONFIG_SMP
2040  extern void kick_process(struct task_struct *tsk);
2041 #else
2042  static inline void kick_process(struct task_struct *tsk) { }
2043 #endif
2044 extern void sched_fork(unsigned long clone_flags, struct task_struct *p);
2045 extern void sched_dead(struct task_struct *p);
2046 
2047 extern void proc_caches_init(void);
2048 extern void flush_signals(struct task_struct *);
2049 extern void __flush_signals(struct task_struct *);
2050 extern void ignore_signals(struct task_struct *);
2051 extern void flush_signal_handlers(struct task_struct *, int force_default);
2052 extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
2053 
2054 static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
2055 {
2056 	unsigned long flags;
2057 	int ret;
2058 
2059 	spin_lock_irqsave(&tsk->sighand->siglock, flags);
2060 	ret = dequeue_signal(tsk, mask, info);
2061 	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
2062 
2063 	return ret;
2064 }
2065 
2066 extern void block_all_signals(int (*notifier)(void *priv), void *priv,
2067 			      sigset_t *mask);
2068 extern void unblock_all_signals(void);
2069 extern void release_task(struct task_struct * p);
2070 extern int send_sig_info(int, struct siginfo *, struct task_struct *);
2071 extern int force_sigsegv(int, struct task_struct *);
2072 extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2073 extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
2074 extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2075 extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *,
2076 				const struct cred *, u32);
2077 extern int kill_pgrp(struct pid *pid, int sig, int priv);
2078 extern int kill_pid(struct pid *pid, int sig, int priv);
2079 extern int kill_proc_info(int, struct siginfo *, pid_t);
2080 extern __must_check bool do_notify_parent(struct task_struct *, int);
2081 extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
2082 extern void force_sig(int, struct task_struct *);
2083 extern int send_sig(int, struct task_struct *, int);
2084 extern int zap_other_threads(struct task_struct *p);
2085 extern struct sigqueue *sigqueue_alloc(void);
2086 extern void sigqueue_free(struct sigqueue *);
2087 extern int send_sigqueue(struct sigqueue *,  struct task_struct *, int group);
2088 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
2089 
2090 static inline void restore_saved_sigmask(void)
2091 {
2092 	if (test_and_clear_restore_sigmask())
2093 		__set_current_blocked(&current->saved_sigmask);
2094 }
2095 
2096 static inline sigset_t *sigmask_to_save(void)
2097 {
2098 	sigset_t *res = &current->blocked;
2099 	if (unlikely(test_restore_sigmask()))
2100 		res = &current->saved_sigmask;
2101 	return res;
2102 }
2103 
2104 static inline int kill_cad_pid(int sig, int priv)
2105 {
2106 	return kill_pid(cad_pid, sig, priv);
2107 }
2108 
2109 /* These can be the second arg to send_sig_info/send_group_sig_info.  */
2110 #define SEND_SIG_NOINFO ((struct siginfo *) 0)
2111 #define SEND_SIG_PRIV	((struct siginfo *) 1)
2112 #define SEND_SIG_FORCED	((struct siginfo *) 2)
2113 
2114 /*
2115  * True if we are on the alternate signal stack.
2116  */
2117 static inline int on_sig_stack(unsigned long sp)
2118 {
2119 #ifdef CONFIG_STACK_GROWSUP
2120 	return sp >= current->sas_ss_sp &&
2121 		sp - current->sas_ss_sp < current->sas_ss_size;
2122 #else
2123 	return sp > current->sas_ss_sp &&
2124 		sp - current->sas_ss_sp <= current->sas_ss_size;
2125 #endif
2126 }
2127 
2128 static inline int sas_ss_flags(unsigned long sp)
2129 {
2130 	return (current->sas_ss_size == 0 ? SS_DISABLE
2131 		: on_sig_stack(sp) ? SS_ONSTACK : 0);
2132 }
2133 
2134 static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig)
2135 {
2136 	if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))
2137 #ifdef CONFIG_STACK_GROWSUP
2138 		return current->sas_ss_sp;
2139 #else
2140 		return current->sas_ss_sp + current->sas_ss_size;
2141 #endif
2142 	return sp;
2143 }
2144 
2145 /*
2146  * Routines for handling mm_structs
2147  */
2148 extern struct mm_struct * mm_alloc(void);
2149 
2150 /* mmdrop drops the mm and the page tables */
2151 extern void __mmdrop(struct mm_struct *);
2152 static inline void mmdrop(struct mm_struct * mm)
2153 {
2154 	if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2155 		__mmdrop(mm);
2156 }
2157 
2158 /* mmput gets rid of the mappings and all user-space */
2159 extern void mmput(struct mm_struct *);
2160 /* Grab a reference to a task's mm, if it is not already going away */
2161 extern struct mm_struct *get_task_mm(struct task_struct *task);
2162 /*
2163  * Grab a reference to a task's mm, if it is not already going away
2164  * and ptrace_may_access with the mode parameter passed to it
2165  * succeeds.
2166  */
2167 extern struct mm_struct *mm_access(struct task_struct *task, unsigned int mode);
2168 /* Remove the current tasks stale references to the old mm_struct */
2169 extern void mm_release(struct task_struct *, struct mm_struct *);
2170 /* Allocate a new mm structure and copy contents from tsk->mm */
2171 extern struct mm_struct *dup_mm(struct task_struct *tsk);
2172 
2173 extern int copy_thread(unsigned long, unsigned long, unsigned long,
2174 			struct task_struct *);
2175 extern void flush_thread(void);
2176 extern void exit_thread(void);
2177 
2178 extern void exit_files(struct task_struct *);
2179 extern void __cleanup_sighand(struct sighand_struct *);
2180 
2181 extern void exit_itimers(struct signal_struct *);
2182 extern void flush_itimer_signals(void);
2183 
2184 extern void do_group_exit(int);
2185 
2186 extern int allow_signal(int);
2187 extern int disallow_signal(int);
2188 
2189 extern int do_execve(const char *,
2190 		     const char __user * const __user *,
2191 		     const char __user * const __user *);
2192 extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
2193 struct task_struct *fork_idle(int);
2194 extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
2195 
2196 extern void set_task_comm(struct task_struct *tsk, char *from);
2197 extern char *get_task_comm(char *to, struct task_struct *tsk);
2198 
2199 #ifdef CONFIG_SMP
2200 void scheduler_ipi(void);
2201 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
2202 #else
2203 static inline void scheduler_ipi(void) { }
2204 static inline unsigned long wait_task_inactive(struct task_struct *p,
2205 					       long match_state)
2206 {
2207 	return 1;
2208 }
2209 #endif
2210 
2211 #define next_task(p) \
2212 	list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
2213 
2214 #define for_each_process(p) \
2215 	for (p = &init_task ; (p = next_task(p)) != &init_task ; )
2216 
2217 extern bool current_is_single_threaded(void);
2218 
2219 /*
2220  * Careful: do_each_thread/while_each_thread is a double loop so
2221  *          'break' will not work as expected - use goto instead.
2222  */
2223 #define do_each_thread(g, t) \
2224 	for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
2225 
2226 #define while_each_thread(g, t) \
2227 	while ((t = next_thread(t)) != g)
2228 
2229 static inline int get_nr_threads(struct task_struct *tsk)
2230 {
2231 	return tsk->signal->nr_threads;
2232 }
2233 
2234 static inline bool thread_group_leader(struct task_struct *p)
2235 {
2236 	return p->exit_signal >= 0;
2237 }
2238 
2239 /* Do to the insanities of de_thread it is possible for a process
2240  * to have the pid of the thread group leader without actually being
2241  * the thread group leader.  For iteration through the pids in proc
2242  * all we care about is that we have a task with the appropriate
2243  * pid, we don't actually care if we have the right task.
2244  */
2245 static inline bool has_group_leader_pid(struct task_struct *p)
2246 {
2247 	return task_pid(p) == p->signal->leader_pid;
2248 }
2249 
2250 static inline
2251 bool same_thread_group(struct task_struct *p1, struct task_struct *p2)
2252 {
2253 	return p1->signal == p2->signal;
2254 }
2255 
2256 static inline struct task_struct *next_thread(const struct task_struct *p)
2257 {
2258 	return list_entry_rcu(p->thread_group.next,
2259 			      struct task_struct, thread_group);
2260 }
2261 
2262 static inline int thread_group_empty(struct task_struct *p)
2263 {
2264 	return list_empty(&p->thread_group);
2265 }
2266 
2267 #define delay_group_leader(p) \
2268 		(thread_group_leader(p) && !thread_group_empty(p))
2269 
2270 /*
2271  * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
2272  * subscriptions and synchronises with wait4().  Also used in procfs.  Also
2273  * pins the final release of task.io_context.  Also protects ->cpuset and
2274  * ->cgroup.subsys[]. And ->vfork_done.
2275  *
2276  * Nests both inside and outside of read_lock(&tasklist_lock).
2277  * It must not be nested with write_lock_irq(&tasklist_lock),
2278  * neither inside nor outside.
2279  */
2280 static inline void task_lock(struct task_struct *p)
2281 {
2282 	spin_lock(&p->alloc_lock);
2283 }
2284 
2285 static inline void task_unlock(struct task_struct *p)
2286 {
2287 	spin_unlock(&p->alloc_lock);
2288 }
2289 
2290 extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
2291 							unsigned long *flags);
2292 
2293 static inline struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
2294 						       unsigned long *flags)
2295 {
2296 	struct sighand_struct *ret;
2297 
2298 	ret = __lock_task_sighand(tsk, flags);
2299 	(void)__cond_lock(&tsk->sighand->siglock, ret);
2300 	return ret;
2301 }
2302 
2303 static inline void unlock_task_sighand(struct task_struct *tsk,
2304 						unsigned long *flags)
2305 {
2306 	spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
2307 }
2308 
2309 #ifdef CONFIG_CGROUPS
2310 static inline void threadgroup_change_begin(struct task_struct *tsk)
2311 {
2312 	down_read(&tsk->signal->group_rwsem);
2313 }
2314 static inline void threadgroup_change_end(struct task_struct *tsk)
2315 {
2316 	up_read(&tsk->signal->group_rwsem);
2317 }
2318 
2319 /**
2320  * threadgroup_lock - lock threadgroup
2321  * @tsk: member task of the threadgroup to lock
2322  *
2323  * Lock the threadgroup @tsk belongs to.  No new task is allowed to enter
2324  * and member tasks aren't allowed to exit (as indicated by PF_EXITING) or
2325  * change ->group_leader/pid.  This is useful for cases where the threadgroup
2326  * needs to stay stable across blockable operations.
2327  *
2328  * fork and exit paths explicitly call threadgroup_change_{begin|end}() for
2329  * synchronization.  While held, no new task will be added to threadgroup
2330  * and no existing live task will have its PF_EXITING set.
2331  *
2332  * de_thread() does threadgroup_change_{begin|end}() when a non-leader
2333  * sub-thread becomes a new leader.
2334  */
2335 static inline void threadgroup_lock(struct task_struct *tsk)
2336 {
2337 	down_write(&tsk->signal->group_rwsem);
2338 }
2339 
2340 /**
2341  * threadgroup_unlock - unlock threadgroup
2342  * @tsk: member task of the threadgroup to unlock
2343  *
2344  * Reverse threadgroup_lock().
2345  */
2346 static inline void threadgroup_unlock(struct task_struct *tsk)
2347 {
2348 	up_write(&tsk->signal->group_rwsem);
2349 }
2350 #else
2351 static inline void threadgroup_change_begin(struct task_struct *tsk) {}
2352 static inline void threadgroup_change_end(struct task_struct *tsk) {}
2353 static inline void threadgroup_lock(struct task_struct *tsk) {}
2354 static inline void threadgroup_unlock(struct task_struct *tsk) {}
2355 #endif
2356 
2357 #ifndef __HAVE_THREAD_FUNCTIONS
2358 
2359 #define task_thread_info(task)	((struct thread_info *)(task)->stack)
2360 #define task_stack_page(task)	((task)->stack)
2361 
2362 static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
2363 {
2364 	*task_thread_info(p) = *task_thread_info(org);
2365 	task_thread_info(p)->task = p;
2366 }
2367 
2368 static inline unsigned long *end_of_stack(struct task_struct *p)
2369 {
2370 	return (unsigned long *)(task_thread_info(p) + 1);
2371 }
2372 
2373 #endif
2374 
2375 static inline int object_is_on_stack(void *obj)
2376 {
2377 	void *stack = task_stack_page(current);
2378 
2379 	return (obj >= stack) && (obj < (stack + THREAD_SIZE));
2380 }
2381 
2382 extern void thread_info_cache_init(void);
2383 
2384 #ifdef CONFIG_DEBUG_STACK_USAGE
2385 static inline unsigned long stack_not_used(struct task_struct *p)
2386 {
2387 	unsigned long *n = end_of_stack(p);
2388 
2389 	do { 	/* Skip over canary */
2390 		n++;
2391 	} while (!*n);
2392 
2393 	return (unsigned long)n - (unsigned long)end_of_stack(p);
2394 }
2395 #endif
2396 
2397 /* set thread flags in other task's structures
2398  * - see asm/thread_info.h for TIF_xxxx flags available
2399  */
2400 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2401 {
2402 	set_ti_thread_flag(task_thread_info(tsk), flag);
2403 }
2404 
2405 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2406 {
2407 	clear_ti_thread_flag(task_thread_info(tsk), flag);
2408 }
2409 
2410 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2411 {
2412 	return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2413 }
2414 
2415 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2416 {
2417 	return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2418 }
2419 
2420 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2421 {
2422 	return test_ti_thread_flag(task_thread_info(tsk), flag);
2423 }
2424 
2425 static inline void set_tsk_need_resched(struct task_struct *tsk)
2426 {
2427 	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2428 }
2429 
2430 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2431 {
2432 	clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2433 }
2434 
2435 static inline int test_tsk_need_resched(struct task_struct *tsk)
2436 {
2437 	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2438 }
2439 
2440 static inline int restart_syscall(void)
2441 {
2442 	set_tsk_thread_flag(current, TIF_SIGPENDING);
2443 	return -ERESTARTNOINTR;
2444 }
2445 
2446 static inline int signal_pending(struct task_struct *p)
2447 {
2448 	return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
2449 }
2450 
2451 static inline int __fatal_signal_pending(struct task_struct *p)
2452 {
2453 	return unlikely(sigismember(&p->pending.signal, SIGKILL));
2454 }
2455 
2456 static inline int fatal_signal_pending(struct task_struct *p)
2457 {
2458 	return signal_pending(p) && __fatal_signal_pending(p);
2459 }
2460 
2461 static inline int signal_pending_state(long state, struct task_struct *p)
2462 {
2463 	if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
2464 		return 0;
2465 	if (!signal_pending(p))
2466 		return 0;
2467 
2468 	return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
2469 }
2470 
2471 /*
2472  * cond_resched() and cond_resched_lock(): latency reduction via
2473  * explicit rescheduling in places that are safe. The return
2474  * value indicates whether a reschedule was done in fact.
2475  * cond_resched_lock() will drop the spinlock before scheduling,
2476  * cond_resched_softirq() will enable bhs before scheduling.
2477  */
2478 extern int _cond_resched(void);
2479 
2480 #define cond_resched() ({			\
2481 	__might_sleep(__FILE__, __LINE__, 0);	\
2482 	_cond_resched();			\
2483 })
2484 
2485 extern int __cond_resched_lock(spinlock_t *lock);
2486 
2487 #ifdef CONFIG_PREEMPT_COUNT
2488 #define PREEMPT_LOCK_OFFSET	PREEMPT_OFFSET
2489 #else
2490 #define PREEMPT_LOCK_OFFSET	0
2491 #endif
2492 
2493 #define cond_resched_lock(lock) ({				\
2494 	__might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);	\
2495 	__cond_resched_lock(lock);				\
2496 })
2497 
2498 extern int __cond_resched_softirq(void);
2499 
2500 #define cond_resched_softirq() ({					\
2501 	__might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET);	\
2502 	__cond_resched_softirq();					\
2503 })
2504 
2505 static inline void cond_resched_rcu(void)
2506 {
2507 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
2508 	rcu_read_unlock();
2509 	cond_resched();
2510 	rcu_read_lock();
2511 #endif
2512 }
2513 
2514 /*
2515  * Does a critical section need to be broken due to another
2516  * task waiting?: (technically does not depend on CONFIG_PREEMPT,
2517  * but a general need for low latency)
2518  */
2519 static inline int spin_needbreak(spinlock_t *lock)
2520 {
2521 #ifdef CONFIG_PREEMPT
2522 	return spin_is_contended(lock);
2523 #else
2524 	return 0;
2525 #endif
2526 }
2527 
2528 /*
2529  * Idle thread specific functions to determine the need_resched
2530  * polling state. We have two versions, one based on TS_POLLING in
2531  * thread_info.status and one based on TIF_POLLING_NRFLAG in
2532  * thread_info.flags
2533  */
2534 #ifdef TS_POLLING
2535 static inline int tsk_is_polling(struct task_struct *p)
2536 {
2537 	return task_thread_info(p)->status & TS_POLLING;
2538 }
2539 static inline void __current_set_polling(void)
2540 {
2541 	current_thread_info()->status |= TS_POLLING;
2542 }
2543 
2544 static inline bool __must_check current_set_polling_and_test(void)
2545 {
2546 	__current_set_polling();
2547 
2548 	/*
2549 	 * Polling state must be visible before we test NEED_RESCHED,
2550 	 * paired by resched_task()
2551 	 */
2552 	smp_mb();
2553 
2554 	return unlikely(tif_need_resched());
2555 }
2556 
2557 static inline void __current_clr_polling(void)
2558 {
2559 	current_thread_info()->status &= ~TS_POLLING;
2560 }
2561 
2562 static inline bool __must_check current_clr_polling_and_test(void)
2563 {
2564 	__current_clr_polling();
2565 
2566 	/*
2567 	 * Polling state must be visible before we test NEED_RESCHED,
2568 	 * paired by resched_task()
2569 	 */
2570 	smp_mb();
2571 
2572 	return unlikely(tif_need_resched());
2573 }
2574 #elif defined(TIF_POLLING_NRFLAG)
2575 static inline int tsk_is_polling(struct task_struct *p)
2576 {
2577 	return test_tsk_thread_flag(p, TIF_POLLING_NRFLAG);
2578 }
2579 
2580 static inline void __current_set_polling(void)
2581 {
2582 	set_thread_flag(TIF_POLLING_NRFLAG);
2583 }
2584 
2585 static inline bool __must_check current_set_polling_and_test(void)
2586 {
2587 	__current_set_polling();
2588 
2589 	/*
2590 	 * Polling state must be visible before we test NEED_RESCHED,
2591 	 * paired by resched_task()
2592 	 *
2593 	 * XXX: assumes set/clear bit are identical barrier wise.
2594 	 */
2595 	smp_mb__after_clear_bit();
2596 
2597 	return unlikely(tif_need_resched());
2598 }
2599 
2600 static inline void __current_clr_polling(void)
2601 {
2602 	clear_thread_flag(TIF_POLLING_NRFLAG);
2603 }
2604 
2605 static inline bool __must_check current_clr_polling_and_test(void)
2606 {
2607 	__current_clr_polling();
2608 
2609 	/*
2610 	 * Polling state must be visible before we test NEED_RESCHED,
2611 	 * paired by resched_task()
2612 	 */
2613 	smp_mb__after_clear_bit();
2614 
2615 	return unlikely(tif_need_resched());
2616 }
2617 
2618 #else
2619 static inline int tsk_is_polling(struct task_struct *p) { return 0; }
2620 static inline void __current_set_polling(void) { }
2621 static inline void __current_clr_polling(void) { }
2622 
2623 static inline bool __must_check current_set_polling_and_test(void)
2624 {
2625 	return unlikely(tif_need_resched());
2626 }
2627 static inline bool __must_check current_clr_polling_and_test(void)
2628 {
2629 	return unlikely(tif_need_resched());
2630 }
2631 #endif
2632 
2633 static __always_inline bool need_resched(void)
2634 {
2635 	return unlikely(tif_need_resched());
2636 }
2637 
2638 /*
2639  * Thread group CPU time accounting.
2640  */
2641 void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
2642 void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
2643 
2644 static inline void thread_group_cputime_init(struct signal_struct *sig)
2645 {
2646 	raw_spin_lock_init(&sig->cputimer.lock);
2647 }
2648 
2649 /*
2650  * Reevaluate whether the task has signals pending delivery.
2651  * Wake the task if so.
2652  * This is required every time the blocked sigset_t changes.
2653  * callers must hold sighand->siglock.
2654  */
2655 extern void recalc_sigpending_and_wake(struct task_struct *t);
2656 extern void recalc_sigpending(void);
2657 
2658 extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
2659 
2660 static inline void signal_wake_up(struct task_struct *t, bool resume)
2661 {
2662 	signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0);
2663 }
2664 static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
2665 {
2666 	signal_wake_up_state(t, resume ? __TASK_TRACED : 0);
2667 }
2668 
2669 /*
2670  * Wrappers for p->thread_info->cpu access. No-op on UP.
2671  */
2672 #ifdef CONFIG_SMP
2673 
2674 static inline unsigned int task_cpu(const struct task_struct *p)
2675 {
2676 	return task_thread_info(p)->cpu;
2677 }
2678 
2679 static inline int task_node(const struct task_struct *p)
2680 {
2681 	return cpu_to_node(task_cpu(p));
2682 }
2683 
2684 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2685 
2686 #else
2687 
2688 static inline unsigned int task_cpu(const struct task_struct *p)
2689 {
2690 	return 0;
2691 }
2692 
2693 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2694 {
2695 }
2696 
2697 #endif /* CONFIG_SMP */
2698 
2699 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2700 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2701 
2702 #ifdef CONFIG_CGROUP_SCHED
2703 extern struct task_group root_task_group;
2704 #endif /* CONFIG_CGROUP_SCHED */
2705 
2706 extern int task_can_switch_user(struct user_struct *up,
2707 					struct task_struct *tsk);
2708 
2709 #ifdef CONFIG_TASK_XACCT
2710 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2711 {
2712 	tsk->ioac.rchar += amt;
2713 }
2714 
2715 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2716 {
2717 	tsk->ioac.wchar += amt;
2718 }
2719 
2720 static inline void inc_syscr(struct task_struct *tsk)
2721 {
2722 	tsk->ioac.syscr++;
2723 }
2724 
2725 static inline void inc_syscw(struct task_struct *tsk)
2726 {
2727 	tsk->ioac.syscw++;
2728 }
2729 #else
2730 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2731 {
2732 }
2733 
2734 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2735 {
2736 }
2737 
2738 static inline void inc_syscr(struct task_struct *tsk)
2739 {
2740 }
2741 
2742 static inline void inc_syscw(struct task_struct *tsk)
2743 {
2744 }
2745 #endif
2746 
2747 #ifndef TASK_SIZE_OF
2748 #define TASK_SIZE_OF(tsk)	TASK_SIZE
2749 #endif
2750 
2751 #ifdef CONFIG_MM_OWNER
2752 extern void mm_update_next_owner(struct mm_struct *mm);
2753 extern void mm_init_owner(struct mm_struct *mm, struct task_struct *p);
2754 #else
2755 static inline void mm_update_next_owner(struct mm_struct *mm)
2756 {
2757 }
2758 
2759 static inline void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
2760 {
2761 }
2762 #endif /* CONFIG_MM_OWNER */
2763 
2764 static inline unsigned long task_rlimit(const struct task_struct *tsk,
2765 		unsigned int limit)
2766 {
2767 	return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_cur);
2768 }
2769 
2770 static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
2771 		unsigned int limit)
2772 {
2773 	return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_max);
2774 }
2775 
2776 static inline unsigned long rlimit(unsigned int limit)
2777 {
2778 	return task_rlimit(current, limit);
2779 }
2780 
2781 static inline unsigned long rlimit_max(unsigned int limit)
2782 {
2783 	return task_rlimit_max(current, limit);
2784 }
2785 
2786 #endif
2787