xref: /linux/include/linux/sched.h (revision 62e7ca5280fd8cbf523970757e13f0324ce0daa0)
1 #ifndef _LINUX_SCHED_H
2 #define _LINUX_SCHED_H
3 
4 #include <uapi/linux/sched.h>
5 
6 #include <linux/sched/prio.h>
7 
8 
9 struct sched_param {
10 	int sched_priority;
11 };
12 
13 #include <asm/param.h>	/* for HZ */
14 
15 #include <linux/capability.h>
16 #include <linux/threads.h>
17 #include <linux/kernel.h>
18 #include <linux/types.h>
19 #include <linux/timex.h>
20 #include <linux/jiffies.h>
21 #include <linux/plist.h>
22 #include <linux/rbtree.h>
23 #include <linux/thread_info.h>
24 #include <linux/cpumask.h>
25 #include <linux/errno.h>
26 #include <linux/nodemask.h>
27 #include <linux/mm_types.h>
28 #include <linux/preempt_mask.h>
29 
30 #include <asm/page.h>
31 #include <asm/ptrace.h>
32 #include <linux/cputime.h>
33 
34 #include <linux/smp.h>
35 #include <linux/sem.h>
36 #include <linux/signal.h>
37 #include <linux/compiler.h>
38 #include <linux/completion.h>
39 #include <linux/pid.h>
40 #include <linux/percpu.h>
41 #include <linux/topology.h>
42 #include <linux/proportions.h>
43 #include <linux/seccomp.h>
44 #include <linux/rcupdate.h>
45 #include <linux/rculist.h>
46 #include <linux/rtmutex.h>
47 
48 #include <linux/time.h>
49 #include <linux/param.h>
50 #include <linux/resource.h>
51 #include <linux/timer.h>
52 #include <linux/hrtimer.h>
53 #include <linux/task_io_accounting.h>
54 #include <linux/latencytop.h>
55 #include <linux/cred.h>
56 #include <linux/llist.h>
57 #include <linux/uidgid.h>
58 #include <linux/gfp.h>
59 
60 #include <asm/processor.h>
61 
62 #define SCHED_ATTR_SIZE_VER0	48	/* sizeof first published struct */
63 
64 /*
65  * Extended scheduling parameters data structure.
66  *
67  * This is needed because the original struct sched_param can not be
68  * altered without introducing ABI issues with legacy applications
69  * (e.g., in sched_getparam()).
70  *
71  * However, the possibility of specifying more than just a priority for
72  * the tasks may be useful for a wide variety of application fields, e.g.,
73  * multimedia, streaming, automation and control, and many others.
74  *
75  * This variant (sched_attr) is meant at describing a so-called
76  * sporadic time-constrained task. In such model a task is specified by:
77  *  - the activation period or minimum instance inter-arrival time;
78  *  - the maximum (or average, depending on the actual scheduling
79  *    discipline) computation time of all instances, a.k.a. runtime;
80  *  - the deadline (relative to the actual activation time) of each
81  *    instance.
82  * Very briefly, a periodic (sporadic) task asks for the execution of
83  * some specific computation --which is typically called an instance--
84  * (at most) every period. Moreover, each instance typically lasts no more
85  * than the runtime and must be completed by time instant t equal to
86  * the instance activation time + the deadline.
87  *
88  * This is reflected by the actual fields of the sched_attr structure:
89  *
90  *  @size		size of the structure, for fwd/bwd compat.
91  *
92  *  @sched_policy	task's scheduling policy
93  *  @sched_flags	for customizing the scheduler behaviour
94  *  @sched_nice		task's nice value      (SCHED_NORMAL/BATCH)
95  *  @sched_priority	task's static priority (SCHED_FIFO/RR)
96  *  @sched_deadline	representative of the task's deadline
97  *  @sched_runtime	representative of the task's runtime
98  *  @sched_period	representative of the task's period
99  *
100  * Given this task model, there are a multiplicity of scheduling algorithms
101  * and policies, that can be used to ensure all the tasks will make their
102  * timing constraints.
103  *
104  * As of now, the SCHED_DEADLINE policy (sched_dl scheduling class) is the
105  * only user of this new interface. More information about the algorithm
106  * available in the scheduling class file or in Documentation/.
107  */
108 struct sched_attr {
109 	u32 size;
110 
111 	u32 sched_policy;
112 	u64 sched_flags;
113 
114 	/* SCHED_NORMAL, SCHED_BATCH */
115 	s32 sched_nice;
116 
117 	/* SCHED_FIFO, SCHED_RR */
118 	u32 sched_priority;
119 
120 	/* SCHED_DEADLINE */
121 	u64 sched_runtime;
122 	u64 sched_deadline;
123 	u64 sched_period;
124 };
125 
126 struct exec_domain;
127 struct futex_pi_state;
128 struct robust_list_head;
129 struct bio_list;
130 struct fs_struct;
131 struct perf_event_context;
132 struct blk_plug;
133 struct filename;
134 
135 #define VMACACHE_BITS 2
136 #define VMACACHE_SIZE (1U << VMACACHE_BITS)
137 #define VMACACHE_MASK (VMACACHE_SIZE - 1)
138 
139 /*
140  * These are the constant used to fake the fixed-point load-average
141  * counting. Some notes:
142  *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
143  *    a load-average precision of 10 bits integer + 11 bits fractional
144  *  - if you want to count load-averages more often, you need more
145  *    precision, or rounding will get you. With 2-second counting freq,
146  *    the EXP_n values would be 1981, 2034 and 2043 if still using only
147  *    11 bit fractions.
148  */
149 extern unsigned long avenrun[];		/* Load averages */
150 extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
151 
152 #define FSHIFT		11		/* nr of bits of precision */
153 #define FIXED_1		(1<<FSHIFT)	/* 1.0 as fixed-point */
154 #define LOAD_FREQ	(5*HZ+1)	/* 5 sec intervals */
155 #define EXP_1		1884		/* 1/exp(5sec/1min) as fixed-point */
156 #define EXP_5		2014		/* 1/exp(5sec/5min) */
157 #define EXP_15		2037		/* 1/exp(5sec/15min) */
158 
159 #define CALC_LOAD(load,exp,n) \
160 	load *= exp; \
161 	load += n*(FIXED_1-exp); \
162 	load >>= FSHIFT;
163 
164 extern unsigned long total_forks;
165 extern int nr_threads;
166 DECLARE_PER_CPU(unsigned long, process_counts);
167 extern int nr_processes(void);
168 extern unsigned long nr_running(void);
169 extern unsigned long nr_iowait(void);
170 extern unsigned long nr_iowait_cpu(int cpu);
171 extern unsigned long this_cpu_load(void);
172 
173 
174 extern void calc_global_load(unsigned long ticks);
175 extern void update_cpu_load_nohz(void);
176 
177 extern unsigned long get_parent_ip(unsigned long addr);
178 
179 extern void dump_cpu_task(int cpu);
180 
181 struct seq_file;
182 struct cfs_rq;
183 struct task_group;
184 #ifdef CONFIG_SCHED_DEBUG
185 extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
186 extern void proc_sched_set_task(struct task_struct *p);
187 extern void
188 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
189 #endif
190 
191 /*
192  * Task state bitmask. NOTE! These bits are also
193  * encoded in fs/proc/array.c: get_task_state().
194  *
195  * We have two separate sets of flags: task->state
196  * is about runnability, while task->exit_state are
197  * about the task exiting. Confusing, but this way
198  * modifying one set can't modify the other one by
199  * mistake.
200  */
201 #define TASK_RUNNING		0
202 #define TASK_INTERRUPTIBLE	1
203 #define TASK_UNINTERRUPTIBLE	2
204 #define __TASK_STOPPED		4
205 #define __TASK_TRACED		8
206 /* in tsk->exit_state */
207 #define EXIT_DEAD		16
208 #define EXIT_ZOMBIE		32
209 #define EXIT_TRACE		(EXIT_ZOMBIE | EXIT_DEAD)
210 /* in tsk->state again */
211 #define TASK_DEAD		64
212 #define TASK_WAKEKILL		128
213 #define TASK_WAKING		256
214 #define TASK_PARKED		512
215 #define TASK_STATE_MAX		1024
216 
217 #define TASK_STATE_TO_CHAR_STR "RSDTtXZxKWP"
218 
219 extern char ___assert_task_state[1 - 2*!!(
220 		sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
221 
222 /* Convenience macros for the sake of set_task_state */
223 #define TASK_KILLABLE		(TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
224 #define TASK_STOPPED		(TASK_WAKEKILL | __TASK_STOPPED)
225 #define TASK_TRACED		(TASK_WAKEKILL | __TASK_TRACED)
226 
227 /* Convenience macros for the sake of wake_up */
228 #define TASK_NORMAL		(TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
229 #define TASK_ALL		(TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
230 
231 /* get_task_state() */
232 #define TASK_REPORT		(TASK_RUNNING | TASK_INTERRUPTIBLE | \
233 				 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
234 				 __TASK_TRACED | EXIT_ZOMBIE | EXIT_DEAD)
235 
236 #define task_is_traced(task)	((task->state & __TASK_TRACED) != 0)
237 #define task_is_stopped(task)	((task->state & __TASK_STOPPED) != 0)
238 #define task_is_stopped_or_traced(task)	\
239 			((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
240 #define task_contributes_to_load(task)	\
241 				((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
242 				 (task->flags & PF_FROZEN) == 0)
243 
244 #define __set_task_state(tsk, state_value)		\
245 	do { (tsk)->state = (state_value); } while (0)
246 #define set_task_state(tsk, state_value)		\
247 	set_mb((tsk)->state, (state_value))
248 
249 /*
250  * set_current_state() includes a barrier so that the write of current->state
251  * is correctly serialised wrt the caller's subsequent test of whether to
252  * actually sleep:
253  *
254  *	set_current_state(TASK_UNINTERRUPTIBLE);
255  *	if (do_i_need_to_sleep())
256  *		schedule();
257  *
258  * If the caller does not need such serialisation then use __set_current_state()
259  */
260 #define __set_current_state(state_value)			\
261 	do { current->state = (state_value); } while (0)
262 #define set_current_state(state_value)		\
263 	set_mb(current->state, (state_value))
264 
265 /* Task command name length */
266 #define TASK_COMM_LEN 16
267 
268 #include <linux/spinlock.h>
269 
270 /*
271  * This serializes "schedule()" and also protects
272  * the run-queue from deletions/modifications (but
273  * _adding_ to the beginning of the run-queue has
274  * a separate lock).
275  */
276 extern rwlock_t tasklist_lock;
277 extern spinlock_t mmlist_lock;
278 
279 struct task_struct;
280 
281 #ifdef CONFIG_PROVE_RCU
282 extern int lockdep_tasklist_lock_is_held(void);
283 #endif /* #ifdef CONFIG_PROVE_RCU */
284 
285 extern void sched_init(void);
286 extern void sched_init_smp(void);
287 extern asmlinkage void schedule_tail(struct task_struct *prev);
288 extern void init_idle(struct task_struct *idle, int cpu);
289 extern void init_idle_bootup_task(struct task_struct *idle);
290 
291 extern int runqueue_is_locked(int cpu);
292 
293 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
294 extern void nohz_balance_enter_idle(int cpu);
295 extern void set_cpu_sd_state_idle(void);
296 extern int get_nohz_timer_target(int pinned);
297 #else
298 static inline void nohz_balance_enter_idle(int cpu) { }
299 static inline void set_cpu_sd_state_idle(void) { }
300 static inline int get_nohz_timer_target(int pinned)
301 {
302 	return smp_processor_id();
303 }
304 #endif
305 
306 /*
307  * Only dump TASK_* tasks. (0 for all tasks)
308  */
309 extern void show_state_filter(unsigned long state_filter);
310 
311 static inline void show_state(void)
312 {
313 	show_state_filter(0);
314 }
315 
316 extern void show_regs(struct pt_regs *);
317 
318 /*
319  * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
320  * task), SP is the stack pointer of the first frame that should be shown in the back
321  * trace (or NULL if the entire call-chain of the task should be shown).
322  */
323 extern void show_stack(struct task_struct *task, unsigned long *sp);
324 
325 void io_schedule(void);
326 long io_schedule_timeout(long timeout);
327 
328 extern void cpu_init (void);
329 extern void trap_init(void);
330 extern void update_process_times(int user);
331 extern void scheduler_tick(void);
332 
333 extern void sched_show_task(struct task_struct *p);
334 
335 #ifdef CONFIG_LOCKUP_DETECTOR
336 extern void touch_softlockup_watchdog(void);
337 extern void touch_softlockup_watchdog_sync(void);
338 extern void touch_all_softlockup_watchdogs(void);
339 extern int proc_dowatchdog_thresh(struct ctl_table *table, int write,
340 				  void __user *buffer,
341 				  size_t *lenp, loff_t *ppos);
342 extern unsigned int  softlockup_panic;
343 void lockup_detector_init(void);
344 #else
345 static inline void touch_softlockup_watchdog(void)
346 {
347 }
348 static inline void touch_softlockup_watchdog_sync(void)
349 {
350 }
351 static inline void touch_all_softlockup_watchdogs(void)
352 {
353 }
354 static inline void lockup_detector_init(void)
355 {
356 }
357 #endif
358 
359 #ifdef CONFIG_DETECT_HUNG_TASK
360 void reset_hung_task_detector(void);
361 #else
362 static inline void reset_hung_task_detector(void)
363 {
364 }
365 #endif
366 
367 /* Attach to any functions which should be ignored in wchan output. */
368 #define __sched		__attribute__((__section__(".sched.text")))
369 
370 /* Linker adds these: start and end of __sched functions */
371 extern char __sched_text_start[], __sched_text_end[];
372 
373 /* Is this address in the __sched functions? */
374 extern int in_sched_functions(unsigned long addr);
375 
376 #define	MAX_SCHEDULE_TIMEOUT	LONG_MAX
377 extern signed long schedule_timeout(signed long timeout);
378 extern signed long schedule_timeout_interruptible(signed long timeout);
379 extern signed long schedule_timeout_killable(signed long timeout);
380 extern signed long schedule_timeout_uninterruptible(signed long timeout);
381 asmlinkage void schedule(void);
382 extern void schedule_preempt_disabled(void);
383 
384 struct nsproxy;
385 struct user_namespace;
386 
387 #ifdef CONFIG_MMU
388 extern void arch_pick_mmap_layout(struct mm_struct *mm);
389 extern unsigned long
390 arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
391 		       unsigned long, unsigned long);
392 extern unsigned long
393 arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
394 			  unsigned long len, unsigned long pgoff,
395 			  unsigned long flags);
396 #else
397 static inline void arch_pick_mmap_layout(struct mm_struct *mm) {}
398 #endif
399 
400 #define SUID_DUMP_DISABLE	0	/* No setuid dumping */
401 #define SUID_DUMP_USER		1	/* Dump as user of process */
402 #define SUID_DUMP_ROOT		2	/* Dump as root */
403 
404 /* mm flags */
405 
406 /* for SUID_DUMP_* above */
407 #define MMF_DUMPABLE_BITS 2
408 #define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
409 
410 extern void set_dumpable(struct mm_struct *mm, int value);
411 /*
412  * This returns the actual value of the suid_dumpable flag. For things
413  * that are using this for checking for privilege transitions, it must
414  * test against SUID_DUMP_USER rather than treating it as a boolean
415  * value.
416  */
417 static inline int __get_dumpable(unsigned long mm_flags)
418 {
419 	return mm_flags & MMF_DUMPABLE_MASK;
420 }
421 
422 static inline int get_dumpable(struct mm_struct *mm)
423 {
424 	return __get_dumpable(mm->flags);
425 }
426 
427 /* coredump filter bits */
428 #define MMF_DUMP_ANON_PRIVATE	2
429 #define MMF_DUMP_ANON_SHARED	3
430 #define MMF_DUMP_MAPPED_PRIVATE	4
431 #define MMF_DUMP_MAPPED_SHARED	5
432 #define MMF_DUMP_ELF_HEADERS	6
433 #define MMF_DUMP_HUGETLB_PRIVATE 7
434 #define MMF_DUMP_HUGETLB_SHARED  8
435 
436 #define MMF_DUMP_FILTER_SHIFT	MMF_DUMPABLE_BITS
437 #define MMF_DUMP_FILTER_BITS	7
438 #define MMF_DUMP_FILTER_MASK \
439 	(((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
440 #define MMF_DUMP_FILTER_DEFAULT \
441 	((1 << MMF_DUMP_ANON_PRIVATE) |	(1 << MMF_DUMP_ANON_SHARED) |\
442 	 (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
443 
444 #ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
445 # define MMF_DUMP_MASK_DEFAULT_ELF	(1 << MMF_DUMP_ELF_HEADERS)
446 #else
447 # define MMF_DUMP_MASK_DEFAULT_ELF	0
448 #endif
449 					/* leave room for more dump flags */
450 #define MMF_VM_MERGEABLE	16	/* KSM may merge identical pages */
451 #define MMF_VM_HUGEPAGE		17	/* set when VM_HUGEPAGE is set on vma */
452 #define MMF_EXE_FILE_CHANGED	18	/* see prctl_set_mm_exe_file() */
453 
454 #define MMF_HAS_UPROBES		19	/* has uprobes */
455 #define MMF_RECALC_UPROBES	20	/* MMF_HAS_UPROBES can be wrong */
456 
457 #define MMF_INIT_MASK		(MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
458 
459 struct sighand_struct {
460 	atomic_t		count;
461 	struct k_sigaction	action[_NSIG];
462 	spinlock_t		siglock;
463 	wait_queue_head_t	signalfd_wqh;
464 };
465 
466 struct pacct_struct {
467 	int			ac_flag;
468 	long			ac_exitcode;
469 	unsigned long		ac_mem;
470 	cputime_t		ac_utime, ac_stime;
471 	unsigned long		ac_minflt, ac_majflt;
472 };
473 
474 struct cpu_itimer {
475 	cputime_t expires;
476 	cputime_t incr;
477 	u32 error;
478 	u32 incr_error;
479 };
480 
481 /**
482  * struct cputime - snaphsot of system and user cputime
483  * @utime: time spent in user mode
484  * @stime: time spent in system mode
485  *
486  * Gathers a generic snapshot of user and system time.
487  */
488 struct cputime {
489 	cputime_t utime;
490 	cputime_t stime;
491 };
492 
493 /**
494  * struct task_cputime - collected CPU time counts
495  * @utime:		time spent in user mode, in &cputime_t units
496  * @stime:		time spent in kernel mode, in &cputime_t units
497  * @sum_exec_runtime:	total time spent on the CPU, in nanoseconds
498  *
499  * This is an extension of struct cputime that includes the total runtime
500  * spent by the task from the scheduler point of view.
501  *
502  * As a result, this structure groups together three kinds of CPU time
503  * that are tracked for threads and thread groups.  Most things considering
504  * CPU time want to group these counts together and treat all three
505  * of them in parallel.
506  */
507 struct task_cputime {
508 	cputime_t utime;
509 	cputime_t stime;
510 	unsigned long long sum_exec_runtime;
511 };
512 /* Alternate field names when used to cache expirations. */
513 #define prof_exp	stime
514 #define virt_exp	utime
515 #define sched_exp	sum_exec_runtime
516 
517 #define INIT_CPUTIME	\
518 	(struct task_cputime) {					\
519 		.utime = 0,					\
520 		.stime = 0,					\
521 		.sum_exec_runtime = 0,				\
522 	}
523 
524 #ifdef CONFIG_PREEMPT_COUNT
525 #define PREEMPT_DISABLED	(1 + PREEMPT_ENABLED)
526 #else
527 #define PREEMPT_DISABLED	PREEMPT_ENABLED
528 #endif
529 
530 /*
531  * Disable preemption until the scheduler is running.
532  * Reset by start_kernel()->sched_init()->init_idle().
533  *
534  * We include PREEMPT_ACTIVE to avoid cond_resched() from working
535  * before the scheduler is active -- see should_resched().
536  */
537 #define INIT_PREEMPT_COUNT	(PREEMPT_DISABLED + PREEMPT_ACTIVE)
538 
539 /**
540  * struct thread_group_cputimer - thread group interval timer counts
541  * @cputime:		thread group interval timers.
542  * @running:		non-zero when there are timers running and
543  * 			@cputime receives updates.
544  * @lock:		lock for fields in this struct.
545  *
546  * This structure contains the version of task_cputime, above, that is
547  * used for thread group CPU timer calculations.
548  */
549 struct thread_group_cputimer {
550 	struct task_cputime cputime;
551 	int running;
552 	raw_spinlock_t lock;
553 };
554 
555 #include <linux/rwsem.h>
556 struct autogroup;
557 
558 /*
559  * NOTE! "signal_struct" does not have its own
560  * locking, because a shared signal_struct always
561  * implies a shared sighand_struct, so locking
562  * sighand_struct is always a proper superset of
563  * the locking of signal_struct.
564  */
565 struct signal_struct {
566 	atomic_t		sigcnt;
567 	atomic_t		live;
568 	int			nr_threads;
569 	struct list_head	thread_head;
570 
571 	wait_queue_head_t	wait_chldexit;	/* for wait4() */
572 
573 	/* current thread group signal load-balancing target: */
574 	struct task_struct	*curr_target;
575 
576 	/* shared signal handling: */
577 	struct sigpending	shared_pending;
578 
579 	/* thread group exit support */
580 	int			group_exit_code;
581 	/* overloaded:
582 	 * - notify group_exit_task when ->count is equal to notify_count
583 	 * - everyone except group_exit_task is stopped during signal delivery
584 	 *   of fatal signals, group_exit_task processes the signal.
585 	 */
586 	int			notify_count;
587 	struct task_struct	*group_exit_task;
588 
589 	/* thread group stop support, overloads group_exit_code too */
590 	int			group_stop_count;
591 	unsigned int		flags; /* see SIGNAL_* flags below */
592 
593 	/*
594 	 * PR_SET_CHILD_SUBREAPER marks a process, like a service
595 	 * manager, to re-parent orphan (double-forking) child processes
596 	 * to this process instead of 'init'. The service manager is
597 	 * able to receive SIGCHLD signals and is able to investigate
598 	 * the process until it calls wait(). All children of this
599 	 * process will inherit a flag if they should look for a
600 	 * child_subreaper process at exit.
601 	 */
602 	unsigned int		is_child_subreaper:1;
603 	unsigned int		has_child_subreaper:1;
604 
605 	/* POSIX.1b Interval Timers */
606 	int			posix_timer_id;
607 	struct list_head	posix_timers;
608 
609 	/* ITIMER_REAL timer for the process */
610 	struct hrtimer real_timer;
611 	struct pid *leader_pid;
612 	ktime_t it_real_incr;
613 
614 	/*
615 	 * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
616 	 * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
617 	 * values are defined to 0 and 1 respectively
618 	 */
619 	struct cpu_itimer it[2];
620 
621 	/*
622 	 * Thread group totals for process CPU timers.
623 	 * See thread_group_cputimer(), et al, for details.
624 	 */
625 	struct thread_group_cputimer cputimer;
626 
627 	/* Earliest-expiration cache. */
628 	struct task_cputime cputime_expires;
629 
630 	struct list_head cpu_timers[3];
631 
632 	struct pid *tty_old_pgrp;
633 
634 	/* boolean value for session group leader */
635 	int leader;
636 
637 	struct tty_struct *tty; /* NULL if no tty */
638 
639 #ifdef CONFIG_SCHED_AUTOGROUP
640 	struct autogroup *autogroup;
641 #endif
642 	/*
643 	 * Cumulative resource counters for dead threads in the group,
644 	 * and for reaped dead child processes forked by this group.
645 	 * Live threads maintain their own counters and add to these
646 	 * in __exit_signal, except for the group leader.
647 	 */
648 	cputime_t utime, stime, cutime, cstime;
649 	cputime_t gtime;
650 	cputime_t cgtime;
651 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
652 	struct cputime prev_cputime;
653 #endif
654 	unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
655 	unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
656 	unsigned long inblock, oublock, cinblock, coublock;
657 	unsigned long maxrss, cmaxrss;
658 	struct task_io_accounting ioac;
659 
660 	/*
661 	 * Cumulative ns of schedule CPU time fo dead threads in the
662 	 * group, not including a zombie group leader, (This only differs
663 	 * from jiffies_to_ns(utime + stime) if sched_clock uses something
664 	 * other than jiffies.)
665 	 */
666 	unsigned long long sum_sched_runtime;
667 
668 	/*
669 	 * We don't bother to synchronize most readers of this at all,
670 	 * because there is no reader checking a limit that actually needs
671 	 * to get both rlim_cur and rlim_max atomically, and either one
672 	 * alone is a single word that can safely be read normally.
673 	 * getrlimit/setrlimit use task_lock(current->group_leader) to
674 	 * protect this instead of the siglock, because they really
675 	 * have no need to disable irqs.
676 	 */
677 	struct rlimit rlim[RLIM_NLIMITS];
678 
679 #ifdef CONFIG_BSD_PROCESS_ACCT
680 	struct pacct_struct pacct;	/* per-process accounting information */
681 #endif
682 #ifdef CONFIG_TASKSTATS
683 	struct taskstats *stats;
684 #endif
685 #ifdef CONFIG_AUDIT
686 	unsigned audit_tty;
687 	unsigned audit_tty_log_passwd;
688 	struct tty_audit_buf *tty_audit_buf;
689 #endif
690 #ifdef CONFIG_CGROUPS
691 	/*
692 	 * group_rwsem prevents new tasks from entering the threadgroup and
693 	 * member tasks from exiting,a more specifically, setting of
694 	 * PF_EXITING.  fork and exit paths are protected with this rwsem
695 	 * using threadgroup_change_begin/end().  Users which require
696 	 * threadgroup to remain stable should use threadgroup_[un]lock()
697 	 * which also takes care of exec path.  Currently, cgroup is the
698 	 * only user.
699 	 */
700 	struct rw_semaphore group_rwsem;
701 #endif
702 
703 	oom_flags_t oom_flags;
704 	short oom_score_adj;		/* OOM kill score adjustment */
705 	short oom_score_adj_min;	/* OOM kill score adjustment min value.
706 					 * Only settable by CAP_SYS_RESOURCE. */
707 
708 	struct mutex cred_guard_mutex;	/* guard against foreign influences on
709 					 * credential calculations
710 					 * (notably. ptrace) */
711 };
712 
713 /*
714  * Bits in flags field of signal_struct.
715  */
716 #define SIGNAL_STOP_STOPPED	0x00000001 /* job control stop in effect */
717 #define SIGNAL_STOP_CONTINUED	0x00000002 /* SIGCONT since WCONTINUED reap */
718 #define SIGNAL_GROUP_EXIT	0x00000004 /* group exit in progress */
719 #define SIGNAL_GROUP_COREDUMP	0x00000008 /* coredump in progress */
720 /*
721  * Pending notifications to parent.
722  */
723 #define SIGNAL_CLD_STOPPED	0x00000010
724 #define SIGNAL_CLD_CONTINUED	0x00000020
725 #define SIGNAL_CLD_MASK		(SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
726 
727 #define SIGNAL_UNKILLABLE	0x00000040 /* for init: ignore fatal signals */
728 
729 /* If true, all threads except ->group_exit_task have pending SIGKILL */
730 static inline int signal_group_exit(const struct signal_struct *sig)
731 {
732 	return	(sig->flags & SIGNAL_GROUP_EXIT) ||
733 		(sig->group_exit_task != NULL);
734 }
735 
736 /*
737  * Some day this will be a full-fledged user tracking system..
738  */
739 struct user_struct {
740 	atomic_t __count;	/* reference count */
741 	atomic_t processes;	/* How many processes does this user have? */
742 	atomic_t sigpending;	/* How many pending signals does this user have? */
743 #ifdef CONFIG_INOTIFY_USER
744 	atomic_t inotify_watches; /* How many inotify watches does this user have? */
745 	atomic_t inotify_devs;	/* How many inotify devs does this user have opened? */
746 #endif
747 #ifdef CONFIG_FANOTIFY
748 	atomic_t fanotify_listeners;
749 #endif
750 #ifdef CONFIG_EPOLL
751 	atomic_long_t epoll_watches; /* The number of file descriptors currently watched */
752 #endif
753 #ifdef CONFIG_POSIX_MQUEUE
754 	/* protected by mq_lock	*/
755 	unsigned long mq_bytes;	/* How many bytes can be allocated to mqueue? */
756 #endif
757 	unsigned long locked_shm; /* How many pages of mlocked shm ? */
758 
759 #ifdef CONFIG_KEYS
760 	struct key *uid_keyring;	/* UID specific keyring */
761 	struct key *session_keyring;	/* UID's default session keyring */
762 #endif
763 
764 	/* Hash table maintenance information */
765 	struct hlist_node uidhash_node;
766 	kuid_t uid;
767 
768 #ifdef CONFIG_PERF_EVENTS
769 	atomic_long_t locked_vm;
770 #endif
771 };
772 
773 extern int uids_sysfs_init(void);
774 
775 extern struct user_struct *find_user(kuid_t);
776 
777 extern struct user_struct root_user;
778 #define INIT_USER (&root_user)
779 
780 
781 struct backing_dev_info;
782 struct reclaim_state;
783 
784 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
785 struct sched_info {
786 	/* cumulative counters */
787 	unsigned long pcount;	      /* # of times run on this cpu */
788 	unsigned long long run_delay; /* time spent waiting on a runqueue */
789 
790 	/* timestamps */
791 	unsigned long long last_arrival,/* when we last ran on a cpu */
792 			   last_queued;	/* when we were last queued to run */
793 };
794 #endif /* defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) */
795 
796 #ifdef CONFIG_TASK_DELAY_ACCT
797 struct task_delay_info {
798 	spinlock_t	lock;
799 	unsigned int	flags;	/* Private per-task flags */
800 
801 	/* For each stat XXX, add following, aligned appropriately
802 	 *
803 	 * struct timespec XXX_start, XXX_end;
804 	 * u64 XXX_delay;
805 	 * u32 XXX_count;
806 	 *
807 	 * Atomicity of updates to XXX_delay, XXX_count protected by
808 	 * single lock above (split into XXX_lock if contention is an issue).
809 	 */
810 
811 	/*
812 	 * XXX_count is incremented on every XXX operation, the delay
813 	 * associated with the operation is added to XXX_delay.
814 	 * XXX_delay contains the accumulated delay time in nanoseconds.
815 	 */
816 	u64 blkio_start;	/* Shared by blkio, swapin */
817 	u64 blkio_delay;	/* wait for sync block io completion */
818 	u64 swapin_delay;	/* wait for swapin block io completion */
819 	u32 blkio_count;	/* total count of the number of sync block */
820 				/* io operations performed */
821 	u32 swapin_count;	/* total count of the number of swapin block */
822 				/* io operations performed */
823 
824 	u64 freepages_start;
825 	u64 freepages_delay;	/* wait for memory reclaim */
826 	u32 freepages_count;	/* total count of memory reclaim */
827 };
828 #endif	/* CONFIG_TASK_DELAY_ACCT */
829 
830 static inline int sched_info_on(void)
831 {
832 #ifdef CONFIG_SCHEDSTATS
833 	return 1;
834 #elif defined(CONFIG_TASK_DELAY_ACCT)
835 	extern int delayacct_on;
836 	return delayacct_on;
837 #else
838 	return 0;
839 #endif
840 }
841 
842 enum cpu_idle_type {
843 	CPU_IDLE,
844 	CPU_NOT_IDLE,
845 	CPU_NEWLY_IDLE,
846 	CPU_MAX_IDLE_TYPES
847 };
848 
849 /*
850  * Increase resolution of cpu_capacity calculations
851  */
852 #define SCHED_CAPACITY_SHIFT	10
853 #define SCHED_CAPACITY_SCALE	(1L << SCHED_CAPACITY_SHIFT)
854 
855 /*
856  * sched-domains (multiprocessor balancing) declarations:
857  */
858 #ifdef CONFIG_SMP
859 #define SD_LOAD_BALANCE		0x0001	/* Do load balancing on this domain. */
860 #define SD_BALANCE_NEWIDLE	0x0002	/* Balance when about to become idle */
861 #define SD_BALANCE_EXEC		0x0004	/* Balance on exec */
862 #define SD_BALANCE_FORK		0x0008	/* Balance on fork, clone */
863 #define SD_BALANCE_WAKE		0x0010  /* Balance on wakeup */
864 #define SD_WAKE_AFFINE		0x0020	/* Wake task to waking CPU */
865 #define SD_SHARE_CPUCAPACITY	0x0080	/* Domain members share cpu power */
866 #define SD_SHARE_POWERDOMAIN	0x0100	/* Domain members share power domain */
867 #define SD_SHARE_PKG_RESOURCES	0x0200	/* Domain members share cpu pkg resources */
868 #define SD_SERIALIZE		0x0400	/* Only a single load balancing instance */
869 #define SD_ASYM_PACKING		0x0800  /* Place busy groups earlier in the domain */
870 #define SD_PREFER_SIBLING	0x1000	/* Prefer to place tasks in a sibling domain */
871 #define SD_OVERLAP		0x2000	/* sched_domains of this level overlap */
872 #define SD_NUMA			0x4000	/* cross-node balancing */
873 
874 #ifdef CONFIG_SCHED_SMT
875 static inline int cpu_smt_flags(void)
876 {
877 	return SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
878 }
879 #endif
880 
881 #ifdef CONFIG_SCHED_MC
882 static inline int cpu_core_flags(void)
883 {
884 	return SD_SHARE_PKG_RESOURCES;
885 }
886 #endif
887 
888 #ifdef CONFIG_NUMA
889 static inline int cpu_numa_flags(void)
890 {
891 	return SD_NUMA;
892 }
893 #endif
894 
895 struct sched_domain_attr {
896 	int relax_domain_level;
897 };
898 
899 #define SD_ATTR_INIT	(struct sched_domain_attr) {	\
900 	.relax_domain_level = -1,			\
901 }
902 
903 extern int sched_domain_level_max;
904 
905 struct sched_group;
906 
907 struct sched_domain {
908 	/* These fields must be setup */
909 	struct sched_domain *parent;	/* top domain must be null terminated */
910 	struct sched_domain *child;	/* bottom domain must be null terminated */
911 	struct sched_group *groups;	/* the balancing groups of the domain */
912 	unsigned long min_interval;	/* Minimum balance interval ms */
913 	unsigned long max_interval;	/* Maximum balance interval ms */
914 	unsigned int busy_factor;	/* less balancing by factor if busy */
915 	unsigned int imbalance_pct;	/* No balance until over watermark */
916 	unsigned int cache_nice_tries;	/* Leave cache hot tasks for # tries */
917 	unsigned int busy_idx;
918 	unsigned int idle_idx;
919 	unsigned int newidle_idx;
920 	unsigned int wake_idx;
921 	unsigned int forkexec_idx;
922 	unsigned int smt_gain;
923 
924 	int nohz_idle;			/* NOHZ IDLE status */
925 	int flags;			/* See SD_* */
926 	int level;
927 
928 	/* Runtime fields. */
929 	unsigned long last_balance;	/* init to jiffies. units in jiffies */
930 	unsigned int balance_interval;	/* initialise to 1. units in ms. */
931 	unsigned int nr_balance_failed; /* initialise to 0 */
932 
933 	/* idle_balance() stats */
934 	u64 max_newidle_lb_cost;
935 	unsigned long next_decay_max_lb_cost;
936 
937 #ifdef CONFIG_SCHEDSTATS
938 	/* load_balance() stats */
939 	unsigned int lb_count[CPU_MAX_IDLE_TYPES];
940 	unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
941 	unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
942 	unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
943 	unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
944 	unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
945 	unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
946 	unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
947 
948 	/* Active load balancing */
949 	unsigned int alb_count;
950 	unsigned int alb_failed;
951 	unsigned int alb_pushed;
952 
953 	/* SD_BALANCE_EXEC stats */
954 	unsigned int sbe_count;
955 	unsigned int sbe_balanced;
956 	unsigned int sbe_pushed;
957 
958 	/* SD_BALANCE_FORK stats */
959 	unsigned int sbf_count;
960 	unsigned int sbf_balanced;
961 	unsigned int sbf_pushed;
962 
963 	/* try_to_wake_up() stats */
964 	unsigned int ttwu_wake_remote;
965 	unsigned int ttwu_move_affine;
966 	unsigned int ttwu_move_balance;
967 #endif
968 #ifdef CONFIG_SCHED_DEBUG
969 	char *name;
970 #endif
971 	union {
972 		void *private;		/* used during construction */
973 		struct rcu_head rcu;	/* used during destruction */
974 	};
975 
976 	unsigned int span_weight;
977 	/*
978 	 * Span of all CPUs in this domain.
979 	 *
980 	 * NOTE: this field is variable length. (Allocated dynamically
981 	 * by attaching extra space to the end of the structure,
982 	 * depending on how many CPUs the kernel has booted up with)
983 	 */
984 	unsigned long span[0];
985 };
986 
987 static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
988 {
989 	return to_cpumask(sd->span);
990 }
991 
992 extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
993 				    struct sched_domain_attr *dattr_new);
994 
995 /* Allocate an array of sched domains, for partition_sched_domains(). */
996 cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
997 void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
998 
999 bool cpus_share_cache(int this_cpu, int that_cpu);
1000 
1001 typedef const struct cpumask *(*sched_domain_mask_f)(int cpu);
1002 typedef int (*sched_domain_flags_f)(void);
1003 
1004 #define SDTL_OVERLAP	0x01
1005 
1006 struct sd_data {
1007 	struct sched_domain **__percpu sd;
1008 	struct sched_group **__percpu sg;
1009 	struct sched_group_capacity **__percpu sgc;
1010 };
1011 
1012 struct sched_domain_topology_level {
1013 	sched_domain_mask_f mask;
1014 	sched_domain_flags_f sd_flags;
1015 	int		    flags;
1016 	int		    numa_level;
1017 	struct sd_data      data;
1018 #ifdef CONFIG_SCHED_DEBUG
1019 	char                *name;
1020 #endif
1021 };
1022 
1023 extern struct sched_domain_topology_level *sched_domain_topology;
1024 
1025 extern void set_sched_topology(struct sched_domain_topology_level *tl);
1026 
1027 #ifdef CONFIG_SCHED_DEBUG
1028 # define SD_INIT_NAME(type)		.name = #type
1029 #else
1030 # define SD_INIT_NAME(type)
1031 #endif
1032 
1033 #else /* CONFIG_SMP */
1034 
1035 struct sched_domain_attr;
1036 
1037 static inline void
1038 partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1039 			struct sched_domain_attr *dattr_new)
1040 {
1041 }
1042 
1043 static inline bool cpus_share_cache(int this_cpu, int that_cpu)
1044 {
1045 	return true;
1046 }
1047 
1048 #endif	/* !CONFIG_SMP */
1049 
1050 
1051 struct io_context;			/* See blkdev.h */
1052 
1053 
1054 #ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
1055 extern void prefetch_stack(struct task_struct *t);
1056 #else
1057 static inline void prefetch_stack(struct task_struct *t) { }
1058 #endif
1059 
1060 struct audit_context;		/* See audit.c */
1061 struct mempolicy;
1062 struct pipe_inode_info;
1063 struct uts_namespace;
1064 
1065 struct load_weight {
1066 	unsigned long weight;
1067 	u32 inv_weight;
1068 };
1069 
1070 struct sched_avg {
1071 	/*
1072 	 * These sums represent an infinite geometric series and so are bound
1073 	 * above by 1024/(1-y).  Thus we only need a u32 to store them for all
1074 	 * choices of y < 1-2^(-32)*1024.
1075 	 */
1076 	u32 runnable_avg_sum, runnable_avg_period;
1077 	u64 last_runnable_update;
1078 	s64 decay_count;
1079 	unsigned long load_avg_contrib;
1080 };
1081 
1082 #ifdef CONFIG_SCHEDSTATS
1083 struct sched_statistics {
1084 	u64			wait_start;
1085 	u64			wait_max;
1086 	u64			wait_count;
1087 	u64			wait_sum;
1088 	u64			iowait_count;
1089 	u64			iowait_sum;
1090 
1091 	u64			sleep_start;
1092 	u64			sleep_max;
1093 	s64			sum_sleep_runtime;
1094 
1095 	u64			block_start;
1096 	u64			block_max;
1097 	u64			exec_max;
1098 	u64			slice_max;
1099 
1100 	u64			nr_migrations_cold;
1101 	u64			nr_failed_migrations_affine;
1102 	u64			nr_failed_migrations_running;
1103 	u64			nr_failed_migrations_hot;
1104 	u64			nr_forced_migrations;
1105 
1106 	u64			nr_wakeups;
1107 	u64			nr_wakeups_sync;
1108 	u64			nr_wakeups_migrate;
1109 	u64			nr_wakeups_local;
1110 	u64			nr_wakeups_remote;
1111 	u64			nr_wakeups_affine;
1112 	u64			nr_wakeups_affine_attempts;
1113 	u64			nr_wakeups_passive;
1114 	u64			nr_wakeups_idle;
1115 };
1116 #endif
1117 
1118 struct sched_entity {
1119 	struct load_weight	load;		/* for load-balancing */
1120 	struct rb_node		run_node;
1121 	struct list_head	group_node;
1122 	unsigned int		on_rq;
1123 
1124 	u64			exec_start;
1125 	u64			sum_exec_runtime;
1126 	u64			vruntime;
1127 	u64			prev_sum_exec_runtime;
1128 
1129 	u64			nr_migrations;
1130 
1131 #ifdef CONFIG_SCHEDSTATS
1132 	struct sched_statistics statistics;
1133 #endif
1134 
1135 #ifdef CONFIG_FAIR_GROUP_SCHED
1136 	int			depth;
1137 	struct sched_entity	*parent;
1138 	/* rq on which this entity is (to be) queued: */
1139 	struct cfs_rq		*cfs_rq;
1140 	/* rq "owned" by this entity/group: */
1141 	struct cfs_rq		*my_q;
1142 #endif
1143 
1144 #ifdef CONFIG_SMP
1145 	/* Per-entity load-tracking */
1146 	struct sched_avg	avg;
1147 #endif
1148 };
1149 
1150 struct sched_rt_entity {
1151 	struct list_head run_list;
1152 	unsigned long timeout;
1153 	unsigned long watchdog_stamp;
1154 	unsigned int time_slice;
1155 
1156 	struct sched_rt_entity *back;
1157 #ifdef CONFIG_RT_GROUP_SCHED
1158 	struct sched_rt_entity	*parent;
1159 	/* rq on which this entity is (to be) queued: */
1160 	struct rt_rq		*rt_rq;
1161 	/* rq "owned" by this entity/group: */
1162 	struct rt_rq		*my_q;
1163 #endif
1164 };
1165 
1166 struct sched_dl_entity {
1167 	struct rb_node	rb_node;
1168 
1169 	/*
1170 	 * Original scheduling parameters. Copied here from sched_attr
1171 	 * during sched_setattr(), they will remain the same until
1172 	 * the next sched_setattr().
1173 	 */
1174 	u64 dl_runtime;		/* maximum runtime for each instance	*/
1175 	u64 dl_deadline;	/* relative deadline of each instance	*/
1176 	u64 dl_period;		/* separation of two instances (period) */
1177 	u64 dl_bw;		/* dl_runtime / dl_deadline		*/
1178 
1179 	/*
1180 	 * Actual scheduling parameters. Initialized with the values above,
1181 	 * they are continously updated during task execution. Note that
1182 	 * the remaining runtime could be < 0 in case we are in overrun.
1183 	 */
1184 	s64 runtime;		/* remaining runtime for this instance	*/
1185 	u64 deadline;		/* absolute deadline for this instance	*/
1186 	unsigned int flags;	/* specifying the scheduler behaviour	*/
1187 
1188 	/*
1189 	 * Some bool flags:
1190 	 *
1191 	 * @dl_throttled tells if we exhausted the runtime. If so, the
1192 	 * task has to wait for a replenishment to be performed at the
1193 	 * next firing of dl_timer.
1194 	 *
1195 	 * @dl_new tells if a new instance arrived. If so we must
1196 	 * start executing it with full runtime and reset its absolute
1197 	 * deadline;
1198 	 *
1199 	 * @dl_boosted tells if we are boosted due to DI. If so we are
1200 	 * outside bandwidth enforcement mechanism (but only until we
1201 	 * exit the critical section);
1202 	 *
1203 	 * @dl_yielded tells if task gave up the cpu before consuming
1204 	 * all its available runtime during the last job.
1205 	 */
1206 	int dl_throttled, dl_new, dl_boosted, dl_yielded;
1207 
1208 	/*
1209 	 * Bandwidth enforcement timer. Each -deadline task has its
1210 	 * own bandwidth to be enforced, thus we need one timer per task.
1211 	 */
1212 	struct hrtimer dl_timer;
1213 };
1214 
1215 struct rcu_node;
1216 
1217 enum perf_event_task_context {
1218 	perf_invalid_context = -1,
1219 	perf_hw_context = 0,
1220 	perf_sw_context,
1221 	perf_nr_task_contexts,
1222 };
1223 
1224 struct task_struct {
1225 	volatile long state;	/* -1 unrunnable, 0 runnable, >0 stopped */
1226 	void *stack;
1227 	atomic_t usage;
1228 	unsigned int flags;	/* per process flags, defined below */
1229 	unsigned int ptrace;
1230 
1231 #ifdef CONFIG_SMP
1232 	struct llist_node wake_entry;
1233 	int on_cpu;
1234 	struct task_struct *last_wakee;
1235 	unsigned long wakee_flips;
1236 	unsigned long wakee_flip_decay_ts;
1237 
1238 	int wake_cpu;
1239 #endif
1240 	int on_rq;
1241 
1242 	int prio, static_prio, normal_prio;
1243 	unsigned int rt_priority;
1244 	const struct sched_class *sched_class;
1245 	struct sched_entity se;
1246 	struct sched_rt_entity rt;
1247 #ifdef CONFIG_CGROUP_SCHED
1248 	struct task_group *sched_task_group;
1249 #endif
1250 	struct sched_dl_entity dl;
1251 
1252 #ifdef CONFIG_PREEMPT_NOTIFIERS
1253 	/* list of struct preempt_notifier: */
1254 	struct hlist_head preempt_notifiers;
1255 #endif
1256 
1257 #ifdef CONFIG_BLK_DEV_IO_TRACE
1258 	unsigned int btrace_seq;
1259 #endif
1260 
1261 	unsigned int policy;
1262 	int nr_cpus_allowed;
1263 	cpumask_t cpus_allowed;
1264 
1265 #ifdef CONFIG_PREEMPT_RCU
1266 	int rcu_read_lock_nesting;
1267 	char rcu_read_unlock_special;
1268 	struct list_head rcu_node_entry;
1269 #endif /* #ifdef CONFIG_PREEMPT_RCU */
1270 #ifdef CONFIG_TREE_PREEMPT_RCU
1271 	struct rcu_node *rcu_blocked_node;
1272 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
1273 
1274 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
1275 	struct sched_info sched_info;
1276 #endif
1277 
1278 	struct list_head tasks;
1279 #ifdef CONFIG_SMP
1280 	struct plist_node pushable_tasks;
1281 	struct rb_node pushable_dl_tasks;
1282 #endif
1283 
1284 	struct mm_struct *mm, *active_mm;
1285 #ifdef CONFIG_COMPAT_BRK
1286 	unsigned brk_randomized:1;
1287 #endif
1288 	/* per-thread vma caching */
1289 	u32 vmacache_seqnum;
1290 	struct vm_area_struct *vmacache[VMACACHE_SIZE];
1291 #if defined(SPLIT_RSS_COUNTING)
1292 	struct task_rss_stat	rss_stat;
1293 #endif
1294 /* task state */
1295 	int exit_state;
1296 	int exit_code, exit_signal;
1297 	int pdeath_signal;  /*  The signal sent when the parent dies  */
1298 	unsigned int jobctl;	/* JOBCTL_*, siglock protected */
1299 
1300 	/* Used for emulating ABI behavior of previous Linux versions */
1301 	unsigned int personality;
1302 
1303 	unsigned in_execve:1;	/* Tell the LSMs that the process is doing an
1304 				 * execve */
1305 	unsigned in_iowait:1;
1306 
1307 	/* Revert to default priority/policy when forking */
1308 	unsigned sched_reset_on_fork:1;
1309 	unsigned sched_contributes_to_load:1;
1310 
1311 	unsigned long atomic_flags; /* Flags needing atomic access. */
1312 
1313 	pid_t pid;
1314 	pid_t tgid;
1315 
1316 #ifdef CONFIG_CC_STACKPROTECTOR
1317 	/* Canary value for the -fstack-protector gcc feature */
1318 	unsigned long stack_canary;
1319 #endif
1320 	/*
1321 	 * pointers to (original) parent process, youngest child, younger sibling,
1322 	 * older sibling, respectively.  (p->father can be replaced with
1323 	 * p->real_parent->pid)
1324 	 */
1325 	struct task_struct __rcu *real_parent; /* real parent process */
1326 	struct task_struct __rcu *parent; /* recipient of SIGCHLD, wait4() reports */
1327 	/*
1328 	 * children/sibling forms the list of my natural children
1329 	 */
1330 	struct list_head children;	/* list of my children */
1331 	struct list_head sibling;	/* linkage in my parent's children list */
1332 	struct task_struct *group_leader;	/* threadgroup leader */
1333 
1334 	/*
1335 	 * ptraced is the list of tasks this task is using ptrace on.
1336 	 * This includes both natural children and PTRACE_ATTACH targets.
1337 	 * p->ptrace_entry is p's link on the p->parent->ptraced list.
1338 	 */
1339 	struct list_head ptraced;
1340 	struct list_head ptrace_entry;
1341 
1342 	/* PID/PID hash table linkage. */
1343 	struct pid_link pids[PIDTYPE_MAX];
1344 	struct list_head thread_group;
1345 	struct list_head thread_node;
1346 
1347 	struct completion *vfork_done;		/* for vfork() */
1348 	int __user *set_child_tid;		/* CLONE_CHILD_SETTID */
1349 	int __user *clear_child_tid;		/* CLONE_CHILD_CLEARTID */
1350 
1351 	cputime_t utime, stime, utimescaled, stimescaled;
1352 	cputime_t gtime;
1353 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
1354 	struct cputime prev_cputime;
1355 #endif
1356 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1357 	seqlock_t vtime_seqlock;
1358 	unsigned long long vtime_snap;
1359 	enum {
1360 		VTIME_SLEEPING = 0,
1361 		VTIME_USER,
1362 		VTIME_SYS,
1363 	} vtime_snap_whence;
1364 #endif
1365 	unsigned long nvcsw, nivcsw; /* context switch counts */
1366 	u64 start_time;		/* monotonic time in nsec */
1367 	u64 real_start_time;	/* boot based time in nsec */
1368 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1369 	unsigned long min_flt, maj_flt;
1370 
1371 	struct task_cputime cputime_expires;
1372 	struct list_head cpu_timers[3];
1373 
1374 /* process credentials */
1375 	const struct cred __rcu *real_cred; /* objective and real subjective task
1376 					 * credentials (COW) */
1377 	const struct cred __rcu *cred;	/* effective (overridable) subjective task
1378 					 * credentials (COW) */
1379 	char comm[TASK_COMM_LEN]; /* executable name excluding path
1380 				     - access with [gs]et_task_comm (which lock
1381 				       it with task_lock())
1382 				     - initialized normally by setup_new_exec */
1383 /* file system info */
1384 	int link_count, total_link_count;
1385 #ifdef CONFIG_SYSVIPC
1386 /* ipc stuff */
1387 	struct sysv_sem sysvsem;
1388 #endif
1389 #ifdef CONFIG_DETECT_HUNG_TASK
1390 /* hung task detection */
1391 	unsigned long last_switch_count;
1392 #endif
1393 /* CPU-specific state of this task */
1394 	struct thread_struct thread;
1395 /* filesystem information */
1396 	struct fs_struct *fs;
1397 /* open file information */
1398 	struct files_struct *files;
1399 /* namespaces */
1400 	struct nsproxy *nsproxy;
1401 /* signal handlers */
1402 	struct signal_struct *signal;
1403 	struct sighand_struct *sighand;
1404 
1405 	sigset_t blocked, real_blocked;
1406 	sigset_t saved_sigmask;	/* restored if set_restore_sigmask() was used */
1407 	struct sigpending pending;
1408 
1409 	unsigned long sas_ss_sp;
1410 	size_t sas_ss_size;
1411 	int (*notifier)(void *priv);
1412 	void *notifier_data;
1413 	sigset_t *notifier_mask;
1414 	struct callback_head *task_works;
1415 
1416 	struct audit_context *audit_context;
1417 #ifdef CONFIG_AUDITSYSCALL
1418 	kuid_t loginuid;
1419 	unsigned int sessionid;
1420 #endif
1421 	struct seccomp seccomp;
1422 
1423 /* Thread group tracking */
1424    	u32 parent_exec_id;
1425    	u32 self_exec_id;
1426 /* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1427  * mempolicy */
1428 	spinlock_t alloc_lock;
1429 
1430 	/* Protection of the PI data structures: */
1431 	raw_spinlock_t pi_lock;
1432 
1433 #ifdef CONFIG_RT_MUTEXES
1434 	/* PI waiters blocked on a rt_mutex held by this task */
1435 	struct rb_root pi_waiters;
1436 	struct rb_node *pi_waiters_leftmost;
1437 	/* Deadlock detection and priority inheritance handling */
1438 	struct rt_mutex_waiter *pi_blocked_on;
1439 #endif
1440 
1441 #ifdef CONFIG_DEBUG_MUTEXES
1442 	/* mutex deadlock detection */
1443 	struct mutex_waiter *blocked_on;
1444 #endif
1445 #ifdef CONFIG_TRACE_IRQFLAGS
1446 	unsigned int irq_events;
1447 	unsigned long hardirq_enable_ip;
1448 	unsigned long hardirq_disable_ip;
1449 	unsigned int hardirq_enable_event;
1450 	unsigned int hardirq_disable_event;
1451 	int hardirqs_enabled;
1452 	int hardirq_context;
1453 	unsigned long softirq_disable_ip;
1454 	unsigned long softirq_enable_ip;
1455 	unsigned int softirq_disable_event;
1456 	unsigned int softirq_enable_event;
1457 	int softirqs_enabled;
1458 	int softirq_context;
1459 #endif
1460 #ifdef CONFIG_LOCKDEP
1461 # define MAX_LOCK_DEPTH 48UL
1462 	u64 curr_chain_key;
1463 	int lockdep_depth;
1464 	unsigned int lockdep_recursion;
1465 	struct held_lock held_locks[MAX_LOCK_DEPTH];
1466 	gfp_t lockdep_reclaim_gfp;
1467 #endif
1468 
1469 /* journalling filesystem info */
1470 	void *journal_info;
1471 
1472 /* stacked block device info */
1473 	struct bio_list *bio_list;
1474 
1475 #ifdef CONFIG_BLOCK
1476 /* stack plugging */
1477 	struct blk_plug *plug;
1478 #endif
1479 
1480 /* VM state */
1481 	struct reclaim_state *reclaim_state;
1482 
1483 	struct backing_dev_info *backing_dev_info;
1484 
1485 	struct io_context *io_context;
1486 
1487 	unsigned long ptrace_message;
1488 	siginfo_t *last_siginfo; /* For ptrace use.  */
1489 	struct task_io_accounting ioac;
1490 #if defined(CONFIG_TASK_XACCT)
1491 	u64 acct_rss_mem1;	/* accumulated rss usage */
1492 	u64 acct_vm_mem1;	/* accumulated virtual memory usage */
1493 	cputime_t acct_timexpd;	/* stime + utime since last update */
1494 #endif
1495 #ifdef CONFIG_CPUSETS
1496 	nodemask_t mems_allowed;	/* Protected by alloc_lock */
1497 	seqcount_t mems_allowed_seq;	/* Seqence no to catch updates */
1498 	int cpuset_mem_spread_rotor;
1499 	int cpuset_slab_spread_rotor;
1500 #endif
1501 #ifdef CONFIG_CGROUPS
1502 	/* Control Group info protected by css_set_lock */
1503 	struct css_set __rcu *cgroups;
1504 	/* cg_list protected by css_set_lock and tsk->alloc_lock */
1505 	struct list_head cg_list;
1506 #endif
1507 #ifdef CONFIG_FUTEX
1508 	struct robust_list_head __user *robust_list;
1509 #ifdef CONFIG_COMPAT
1510 	struct compat_robust_list_head __user *compat_robust_list;
1511 #endif
1512 	struct list_head pi_state_list;
1513 	struct futex_pi_state *pi_state_cache;
1514 #endif
1515 #ifdef CONFIG_PERF_EVENTS
1516 	struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1517 	struct mutex perf_event_mutex;
1518 	struct list_head perf_event_list;
1519 #endif
1520 #ifdef CONFIG_DEBUG_PREEMPT
1521 	unsigned long preempt_disable_ip;
1522 #endif
1523 #ifdef CONFIG_NUMA
1524 	struct mempolicy *mempolicy;	/* Protected by alloc_lock */
1525 	short il_next;
1526 	short pref_node_fork;
1527 #endif
1528 #ifdef CONFIG_NUMA_BALANCING
1529 	int numa_scan_seq;
1530 	unsigned int numa_scan_period;
1531 	unsigned int numa_scan_period_max;
1532 	int numa_preferred_nid;
1533 	unsigned long numa_migrate_retry;
1534 	u64 node_stamp;			/* migration stamp  */
1535 	u64 last_task_numa_placement;
1536 	u64 last_sum_exec_runtime;
1537 	struct callback_head numa_work;
1538 
1539 	struct list_head numa_entry;
1540 	struct numa_group *numa_group;
1541 
1542 	/*
1543 	 * Exponential decaying average of faults on a per-node basis.
1544 	 * Scheduling placement decisions are made based on the these counts.
1545 	 * The values remain static for the duration of a PTE scan
1546 	 */
1547 	unsigned long *numa_faults_memory;
1548 	unsigned long total_numa_faults;
1549 
1550 	/*
1551 	 * numa_faults_buffer records faults per node during the current
1552 	 * scan window. When the scan completes, the counts in
1553 	 * numa_faults_memory decay and these values are copied.
1554 	 */
1555 	unsigned long *numa_faults_buffer_memory;
1556 
1557 	/*
1558 	 * Track the nodes the process was running on when a NUMA hinting
1559 	 * fault was incurred.
1560 	 */
1561 	unsigned long *numa_faults_cpu;
1562 	unsigned long *numa_faults_buffer_cpu;
1563 
1564 	/*
1565 	 * numa_faults_locality tracks if faults recorded during the last
1566 	 * scan window were remote/local. The task scan period is adapted
1567 	 * based on the locality of the faults with different weights
1568 	 * depending on whether they were shared or private faults
1569 	 */
1570 	unsigned long numa_faults_locality[2];
1571 
1572 	unsigned long numa_pages_migrated;
1573 #endif /* CONFIG_NUMA_BALANCING */
1574 
1575 	struct rcu_head rcu;
1576 
1577 	/*
1578 	 * cache last used pipe for splice
1579 	 */
1580 	struct pipe_inode_info *splice_pipe;
1581 
1582 	struct page_frag task_frag;
1583 
1584 #ifdef	CONFIG_TASK_DELAY_ACCT
1585 	struct task_delay_info *delays;
1586 #endif
1587 #ifdef CONFIG_FAULT_INJECTION
1588 	int make_it_fail;
1589 #endif
1590 	/*
1591 	 * when (nr_dirtied >= nr_dirtied_pause), it's time to call
1592 	 * balance_dirty_pages() for some dirty throttling pause
1593 	 */
1594 	int nr_dirtied;
1595 	int nr_dirtied_pause;
1596 	unsigned long dirty_paused_when; /* start of a write-and-pause period */
1597 
1598 #ifdef CONFIG_LATENCYTOP
1599 	int latency_record_count;
1600 	struct latency_record latency_record[LT_SAVECOUNT];
1601 #endif
1602 	/*
1603 	 * time slack values; these are used to round up poll() and
1604 	 * select() etc timeout values. These are in nanoseconds.
1605 	 */
1606 	unsigned long timer_slack_ns;
1607 	unsigned long default_timer_slack_ns;
1608 
1609 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1610 	/* Index of current stored address in ret_stack */
1611 	int curr_ret_stack;
1612 	/* Stack of return addresses for return function tracing */
1613 	struct ftrace_ret_stack	*ret_stack;
1614 	/* time stamp for last schedule */
1615 	unsigned long long ftrace_timestamp;
1616 	/*
1617 	 * Number of functions that haven't been traced
1618 	 * because of depth overrun.
1619 	 */
1620 	atomic_t trace_overrun;
1621 	/* Pause for the tracing */
1622 	atomic_t tracing_graph_pause;
1623 #endif
1624 #ifdef CONFIG_TRACING
1625 	/* state flags for use by tracers */
1626 	unsigned long trace;
1627 	/* bitmask and counter of trace recursion */
1628 	unsigned long trace_recursion;
1629 #endif /* CONFIG_TRACING */
1630 #ifdef CONFIG_MEMCG /* memcg uses this to do batch job */
1631 	struct memcg_batch_info {
1632 		int do_batch;	/* incremented when batch uncharge started */
1633 		struct mem_cgroup *memcg; /* target memcg of uncharge */
1634 		unsigned long nr_pages;	/* uncharged usage */
1635 		unsigned long memsw_nr_pages; /* uncharged mem+swap usage */
1636 	} memcg_batch;
1637 	unsigned int memcg_kmem_skip_account;
1638 	struct memcg_oom_info {
1639 		struct mem_cgroup *memcg;
1640 		gfp_t gfp_mask;
1641 		int order;
1642 		unsigned int may_oom:1;
1643 	} memcg_oom;
1644 #endif
1645 #ifdef CONFIG_UPROBES
1646 	struct uprobe_task *utask;
1647 #endif
1648 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1649 	unsigned int	sequential_io;
1650 	unsigned int	sequential_io_avg;
1651 #endif
1652 };
1653 
1654 /* Future-safe accessor for struct task_struct's cpus_allowed. */
1655 #define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
1656 
1657 #define TNF_MIGRATED	0x01
1658 #define TNF_NO_GROUP	0x02
1659 #define TNF_SHARED	0x04
1660 #define TNF_FAULT_LOCAL	0x08
1661 
1662 #ifdef CONFIG_NUMA_BALANCING
1663 extern void task_numa_fault(int last_node, int node, int pages, int flags);
1664 extern pid_t task_numa_group_id(struct task_struct *p);
1665 extern void set_numabalancing_state(bool enabled);
1666 extern void task_numa_free(struct task_struct *p);
1667 extern bool should_numa_migrate_memory(struct task_struct *p, struct page *page,
1668 					int src_nid, int dst_cpu);
1669 #else
1670 static inline void task_numa_fault(int last_node, int node, int pages,
1671 				   int flags)
1672 {
1673 }
1674 static inline pid_t task_numa_group_id(struct task_struct *p)
1675 {
1676 	return 0;
1677 }
1678 static inline void set_numabalancing_state(bool enabled)
1679 {
1680 }
1681 static inline void task_numa_free(struct task_struct *p)
1682 {
1683 }
1684 static inline bool should_numa_migrate_memory(struct task_struct *p,
1685 				struct page *page, int src_nid, int dst_cpu)
1686 {
1687 	return true;
1688 }
1689 #endif
1690 
1691 static inline struct pid *task_pid(struct task_struct *task)
1692 {
1693 	return task->pids[PIDTYPE_PID].pid;
1694 }
1695 
1696 static inline struct pid *task_tgid(struct task_struct *task)
1697 {
1698 	return task->group_leader->pids[PIDTYPE_PID].pid;
1699 }
1700 
1701 /*
1702  * Without tasklist or rcu lock it is not safe to dereference
1703  * the result of task_pgrp/task_session even if task == current,
1704  * we can race with another thread doing sys_setsid/sys_setpgid.
1705  */
1706 static inline struct pid *task_pgrp(struct task_struct *task)
1707 {
1708 	return task->group_leader->pids[PIDTYPE_PGID].pid;
1709 }
1710 
1711 static inline struct pid *task_session(struct task_struct *task)
1712 {
1713 	return task->group_leader->pids[PIDTYPE_SID].pid;
1714 }
1715 
1716 struct pid_namespace;
1717 
1718 /*
1719  * the helpers to get the task's different pids as they are seen
1720  * from various namespaces
1721  *
1722  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1723  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1724  *                     current.
1725  * task_xid_nr_ns()  : id seen from the ns specified;
1726  *
1727  * set_task_vxid()   : assigns a virtual id to a task;
1728  *
1729  * see also pid_nr() etc in include/linux/pid.h
1730  */
1731 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
1732 			struct pid_namespace *ns);
1733 
1734 static inline pid_t task_pid_nr(struct task_struct *tsk)
1735 {
1736 	return tsk->pid;
1737 }
1738 
1739 static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
1740 					struct pid_namespace *ns)
1741 {
1742 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1743 }
1744 
1745 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1746 {
1747 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1748 }
1749 
1750 
1751 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1752 {
1753 	return tsk->tgid;
1754 }
1755 
1756 pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1757 
1758 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1759 {
1760 	return pid_vnr(task_tgid(tsk));
1761 }
1762 
1763 
1764 static inline int pid_alive(const struct task_struct *p);
1765 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1766 {
1767 	pid_t pid = 0;
1768 
1769 	rcu_read_lock();
1770 	if (pid_alive(tsk))
1771 		pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1772 	rcu_read_unlock();
1773 
1774 	return pid;
1775 }
1776 
1777 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1778 {
1779 	return task_ppid_nr_ns(tsk, &init_pid_ns);
1780 }
1781 
1782 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
1783 					struct pid_namespace *ns)
1784 {
1785 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1786 }
1787 
1788 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1789 {
1790 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1791 }
1792 
1793 
1794 static inline pid_t task_session_nr_ns(struct task_struct *tsk,
1795 					struct pid_namespace *ns)
1796 {
1797 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1798 }
1799 
1800 static inline pid_t task_session_vnr(struct task_struct *tsk)
1801 {
1802 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1803 }
1804 
1805 /* obsolete, do not use */
1806 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1807 {
1808 	return task_pgrp_nr_ns(tsk, &init_pid_ns);
1809 }
1810 
1811 /**
1812  * pid_alive - check that a task structure is not stale
1813  * @p: Task structure to be checked.
1814  *
1815  * Test if a process is not yet dead (at most zombie state)
1816  * If pid_alive fails, then pointers within the task structure
1817  * can be stale and must not be dereferenced.
1818  *
1819  * Return: 1 if the process is alive. 0 otherwise.
1820  */
1821 static inline int pid_alive(const struct task_struct *p)
1822 {
1823 	return p->pids[PIDTYPE_PID].pid != NULL;
1824 }
1825 
1826 /**
1827  * is_global_init - check if a task structure is init
1828  * @tsk: Task structure to be checked.
1829  *
1830  * Check if a task structure is the first user space task the kernel created.
1831  *
1832  * Return: 1 if the task structure is init. 0 otherwise.
1833  */
1834 static inline int is_global_init(struct task_struct *tsk)
1835 {
1836 	return tsk->pid == 1;
1837 }
1838 
1839 extern struct pid *cad_pid;
1840 
1841 extern void free_task(struct task_struct *tsk);
1842 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
1843 
1844 extern void __put_task_struct(struct task_struct *t);
1845 
1846 static inline void put_task_struct(struct task_struct *t)
1847 {
1848 	if (atomic_dec_and_test(&t->usage))
1849 		__put_task_struct(t);
1850 }
1851 
1852 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1853 extern void task_cputime(struct task_struct *t,
1854 			 cputime_t *utime, cputime_t *stime);
1855 extern void task_cputime_scaled(struct task_struct *t,
1856 				cputime_t *utimescaled, cputime_t *stimescaled);
1857 extern cputime_t task_gtime(struct task_struct *t);
1858 #else
1859 static inline void task_cputime(struct task_struct *t,
1860 				cputime_t *utime, cputime_t *stime)
1861 {
1862 	if (utime)
1863 		*utime = t->utime;
1864 	if (stime)
1865 		*stime = t->stime;
1866 }
1867 
1868 static inline void task_cputime_scaled(struct task_struct *t,
1869 				       cputime_t *utimescaled,
1870 				       cputime_t *stimescaled)
1871 {
1872 	if (utimescaled)
1873 		*utimescaled = t->utimescaled;
1874 	if (stimescaled)
1875 		*stimescaled = t->stimescaled;
1876 }
1877 
1878 static inline cputime_t task_gtime(struct task_struct *t)
1879 {
1880 	return t->gtime;
1881 }
1882 #endif
1883 extern void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
1884 extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
1885 
1886 /*
1887  * Per process flags
1888  */
1889 #define PF_EXITING	0x00000004	/* getting shut down */
1890 #define PF_EXITPIDONE	0x00000008	/* pi exit done on shut down */
1891 #define PF_VCPU		0x00000010	/* I'm a virtual CPU */
1892 #define PF_WQ_WORKER	0x00000020	/* I'm a workqueue worker */
1893 #define PF_FORKNOEXEC	0x00000040	/* forked but didn't exec */
1894 #define PF_MCE_PROCESS  0x00000080      /* process policy on mce errors */
1895 #define PF_SUPERPRIV	0x00000100	/* used super-user privileges */
1896 #define PF_DUMPCORE	0x00000200	/* dumped core */
1897 #define PF_SIGNALED	0x00000400	/* killed by a signal */
1898 #define PF_MEMALLOC	0x00000800	/* Allocating memory */
1899 #define PF_NPROC_EXCEEDED 0x00001000	/* set_user noticed that RLIMIT_NPROC was exceeded */
1900 #define PF_USED_MATH	0x00002000	/* if unset the fpu must be initialized before use */
1901 #define PF_USED_ASYNC	0x00004000	/* used async_schedule*(), used by module init */
1902 #define PF_NOFREEZE	0x00008000	/* this thread should not be frozen */
1903 #define PF_FROZEN	0x00010000	/* frozen for system suspend */
1904 #define PF_FSTRANS	0x00020000	/* inside a filesystem transaction */
1905 #define PF_KSWAPD	0x00040000	/* I am kswapd */
1906 #define PF_MEMALLOC_NOIO 0x00080000	/* Allocating memory without IO involved */
1907 #define PF_LESS_THROTTLE 0x00100000	/* Throttle me less: I clean memory */
1908 #define PF_KTHREAD	0x00200000	/* I am a kernel thread */
1909 #define PF_RANDOMIZE	0x00400000	/* randomize virtual address space */
1910 #define PF_SWAPWRITE	0x00800000	/* Allowed to write to swap */
1911 #define PF_SPREAD_PAGE	0x01000000	/* Spread page cache over cpuset */
1912 #define PF_SPREAD_SLAB	0x02000000	/* Spread some slab caches over cpuset */
1913 #define PF_NO_SETAFFINITY 0x04000000	/* Userland is not allowed to meddle with cpus_allowed */
1914 #define PF_MCE_EARLY    0x08000000      /* Early kill for mce process policy */
1915 #define PF_MUTEX_TESTER	0x20000000	/* Thread belongs to the rt mutex tester */
1916 #define PF_FREEZER_SKIP	0x40000000	/* Freezer should not count it as freezable */
1917 #define PF_SUSPEND_TASK 0x80000000      /* this thread called freeze_processes and should not be frozen */
1918 
1919 /*
1920  * Only the _current_ task can read/write to tsk->flags, but other
1921  * tasks can access tsk->flags in readonly mode for example
1922  * with tsk_used_math (like during threaded core dumping).
1923  * There is however an exception to this rule during ptrace
1924  * or during fork: the ptracer task is allowed to write to the
1925  * child->flags of its traced child (same goes for fork, the parent
1926  * can write to the child->flags), because we're guaranteed the
1927  * child is not running and in turn not changing child->flags
1928  * at the same time the parent does it.
1929  */
1930 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1931 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1932 #define clear_used_math() clear_stopped_child_used_math(current)
1933 #define set_used_math() set_stopped_child_used_math(current)
1934 #define conditional_stopped_child_used_math(condition, child) \
1935 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1936 #define conditional_used_math(condition) \
1937 	conditional_stopped_child_used_math(condition, current)
1938 #define copy_to_stopped_child_used_math(child) \
1939 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1940 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1941 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1942 #define used_math() tsk_used_math(current)
1943 
1944 /* __GFP_IO isn't allowed if PF_MEMALLOC_NOIO is set in current->flags */
1945 static inline gfp_t memalloc_noio_flags(gfp_t flags)
1946 {
1947 	if (unlikely(current->flags & PF_MEMALLOC_NOIO))
1948 		flags &= ~__GFP_IO;
1949 	return flags;
1950 }
1951 
1952 static inline unsigned int memalloc_noio_save(void)
1953 {
1954 	unsigned int flags = current->flags & PF_MEMALLOC_NOIO;
1955 	current->flags |= PF_MEMALLOC_NOIO;
1956 	return flags;
1957 }
1958 
1959 static inline void memalloc_noio_restore(unsigned int flags)
1960 {
1961 	current->flags = (current->flags & ~PF_MEMALLOC_NOIO) | flags;
1962 }
1963 
1964 /* Per-process atomic flags. */
1965 #define PFA_NO_NEW_PRIVS 0x00000001	/* May not gain new privileges. */
1966 
1967 static inline bool task_no_new_privs(struct task_struct *p)
1968 {
1969 	return test_bit(PFA_NO_NEW_PRIVS, &p->atomic_flags);
1970 }
1971 
1972 static inline void task_set_no_new_privs(struct task_struct *p)
1973 {
1974 	set_bit(PFA_NO_NEW_PRIVS, &p->atomic_flags);
1975 }
1976 
1977 /*
1978  * task->jobctl flags
1979  */
1980 #define JOBCTL_STOP_SIGMASK	0xffff	/* signr of the last group stop */
1981 
1982 #define JOBCTL_STOP_DEQUEUED_BIT 16	/* stop signal dequeued */
1983 #define JOBCTL_STOP_PENDING_BIT	17	/* task should stop for group stop */
1984 #define JOBCTL_STOP_CONSUME_BIT	18	/* consume group stop count */
1985 #define JOBCTL_TRAP_STOP_BIT	19	/* trap for STOP */
1986 #define JOBCTL_TRAP_NOTIFY_BIT	20	/* trap for NOTIFY */
1987 #define JOBCTL_TRAPPING_BIT	21	/* switching to TRACED */
1988 #define JOBCTL_LISTENING_BIT	22	/* ptracer is listening for events */
1989 
1990 #define JOBCTL_STOP_DEQUEUED	(1 << JOBCTL_STOP_DEQUEUED_BIT)
1991 #define JOBCTL_STOP_PENDING	(1 << JOBCTL_STOP_PENDING_BIT)
1992 #define JOBCTL_STOP_CONSUME	(1 << JOBCTL_STOP_CONSUME_BIT)
1993 #define JOBCTL_TRAP_STOP	(1 << JOBCTL_TRAP_STOP_BIT)
1994 #define JOBCTL_TRAP_NOTIFY	(1 << JOBCTL_TRAP_NOTIFY_BIT)
1995 #define JOBCTL_TRAPPING		(1 << JOBCTL_TRAPPING_BIT)
1996 #define JOBCTL_LISTENING	(1 << JOBCTL_LISTENING_BIT)
1997 
1998 #define JOBCTL_TRAP_MASK	(JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
1999 #define JOBCTL_PENDING_MASK	(JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)
2000 
2001 extern bool task_set_jobctl_pending(struct task_struct *task,
2002 				    unsigned int mask);
2003 extern void task_clear_jobctl_trapping(struct task_struct *task);
2004 extern void task_clear_jobctl_pending(struct task_struct *task,
2005 				      unsigned int mask);
2006 
2007 #ifdef CONFIG_PREEMPT_RCU
2008 
2009 #define RCU_READ_UNLOCK_BLOCKED (1 << 0) /* blocked while in RCU read-side. */
2010 #define RCU_READ_UNLOCK_NEED_QS (1 << 1) /* RCU core needs CPU response. */
2011 
2012 static inline void rcu_copy_process(struct task_struct *p)
2013 {
2014 	p->rcu_read_lock_nesting = 0;
2015 	p->rcu_read_unlock_special = 0;
2016 #ifdef CONFIG_TREE_PREEMPT_RCU
2017 	p->rcu_blocked_node = NULL;
2018 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
2019 	INIT_LIST_HEAD(&p->rcu_node_entry);
2020 }
2021 
2022 #else
2023 
2024 static inline void rcu_copy_process(struct task_struct *p)
2025 {
2026 }
2027 
2028 #endif
2029 
2030 static inline void tsk_restore_flags(struct task_struct *task,
2031 				unsigned long orig_flags, unsigned long flags)
2032 {
2033 	task->flags &= ~flags;
2034 	task->flags |= orig_flags & flags;
2035 }
2036 
2037 #ifdef CONFIG_SMP
2038 extern void do_set_cpus_allowed(struct task_struct *p,
2039 			       const struct cpumask *new_mask);
2040 
2041 extern int set_cpus_allowed_ptr(struct task_struct *p,
2042 				const struct cpumask *new_mask);
2043 #else
2044 static inline void do_set_cpus_allowed(struct task_struct *p,
2045 				      const struct cpumask *new_mask)
2046 {
2047 }
2048 static inline int set_cpus_allowed_ptr(struct task_struct *p,
2049 				       const struct cpumask *new_mask)
2050 {
2051 	if (!cpumask_test_cpu(0, new_mask))
2052 		return -EINVAL;
2053 	return 0;
2054 }
2055 #endif
2056 
2057 #ifdef CONFIG_NO_HZ_COMMON
2058 void calc_load_enter_idle(void);
2059 void calc_load_exit_idle(void);
2060 #else
2061 static inline void calc_load_enter_idle(void) { }
2062 static inline void calc_load_exit_idle(void) { }
2063 #endif /* CONFIG_NO_HZ_COMMON */
2064 
2065 #ifndef CONFIG_CPUMASK_OFFSTACK
2066 static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
2067 {
2068 	return set_cpus_allowed_ptr(p, &new_mask);
2069 }
2070 #endif
2071 
2072 /*
2073  * Do not use outside of architecture code which knows its limitations.
2074  *
2075  * sched_clock() has no promise of monotonicity or bounded drift between
2076  * CPUs, use (which you should not) requires disabling IRQs.
2077  *
2078  * Please use one of the three interfaces below.
2079  */
2080 extern unsigned long long notrace sched_clock(void);
2081 /*
2082  * See the comment in kernel/sched/clock.c
2083  */
2084 extern u64 cpu_clock(int cpu);
2085 extern u64 local_clock(void);
2086 extern u64 sched_clock_cpu(int cpu);
2087 
2088 
2089 extern void sched_clock_init(void);
2090 
2091 #ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
2092 static inline void sched_clock_tick(void)
2093 {
2094 }
2095 
2096 static inline void sched_clock_idle_sleep_event(void)
2097 {
2098 }
2099 
2100 static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
2101 {
2102 }
2103 #else
2104 /*
2105  * Architectures can set this to 1 if they have specified
2106  * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
2107  * but then during bootup it turns out that sched_clock()
2108  * is reliable after all:
2109  */
2110 extern int sched_clock_stable(void);
2111 extern void set_sched_clock_stable(void);
2112 extern void clear_sched_clock_stable(void);
2113 
2114 extern void sched_clock_tick(void);
2115 extern void sched_clock_idle_sleep_event(void);
2116 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2117 #endif
2118 
2119 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
2120 /*
2121  * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
2122  * The reason for this explicit opt-in is not to have perf penalty with
2123  * slow sched_clocks.
2124  */
2125 extern void enable_sched_clock_irqtime(void);
2126 extern void disable_sched_clock_irqtime(void);
2127 #else
2128 static inline void enable_sched_clock_irqtime(void) {}
2129 static inline void disable_sched_clock_irqtime(void) {}
2130 #endif
2131 
2132 extern unsigned long long
2133 task_sched_runtime(struct task_struct *task);
2134 
2135 /* sched_exec is called by processes performing an exec */
2136 #ifdef CONFIG_SMP
2137 extern void sched_exec(void);
2138 #else
2139 #define sched_exec()   {}
2140 #endif
2141 
2142 extern void sched_clock_idle_sleep_event(void);
2143 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2144 
2145 #ifdef CONFIG_HOTPLUG_CPU
2146 extern void idle_task_exit(void);
2147 #else
2148 static inline void idle_task_exit(void) {}
2149 #endif
2150 
2151 #if defined(CONFIG_NO_HZ_COMMON) && defined(CONFIG_SMP)
2152 extern void wake_up_nohz_cpu(int cpu);
2153 #else
2154 static inline void wake_up_nohz_cpu(int cpu) { }
2155 #endif
2156 
2157 #ifdef CONFIG_NO_HZ_FULL
2158 extern bool sched_can_stop_tick(void);
2159 extern u64 scheduler_tick_max_deferment(void);
2160 #else
2161 static inline bool sched_can_stop_tick(void) { return false; }
2162 #endif
2163 
2164 #ifdef CONFIG_SCHED_AUTOGROUP
2165 extern void sched_autogroup_create_attach(struct task_struct *p);
2166 extern void sched_autogroup_detach(struct task_struct *p);
2167 extern void sched_autogroup_fork(struct signal_struct *sig);
2168 extern void sched_autogroup_exit(struct signal_struct *sig);
2169 #ifdef CONFIG_PROC_FS
2170 extern void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m);
2171 extern int proc_sched_autogroup_set_nice(struct task_struct *p, int nice);
2172 #endif
2173 #else
2174 static inline void sched_autogroup_create_attach(struct task_struct *p) { }
2175 static inline void sched_autogroup_detach(struct task_struct *p) { }
2176 static inline void sched_autogroup_fork(struct signal_struct *sig) { }
2177 static inline void sched_autogroup_exit(struct signal_struct *sig) { }
2178 #endif
2179 
2180 extern int yield_to(struct task_struct *p, bool preempt);
2181 extern void set_user_nice(struct task_struct *p, long nice);
2182 extern int task_prio(const struct task_struct *p);
2183 /**
2184  * task_nice - return the nice value of a given task.
2185  * @p: the task in question.
2186  *
2187  * Return: The nice value [ -20 ... 0 ... 19 ].
2188  */
2189 static inline int task_nice(const struct task_struct *p)
2190 {
2191 	return PRIO_TO_NICE((p)->static_prio);
2192 }
2193 extern int can_nice(const struct task_struct *p, const int nice);
2194 extern int task_curr(const struct task_struct *p);
2195 extern int idle_cpu(int cpu);
2196 extern int sched_setscheduler(struct task_struct *, int,
2197 			      const struct sched_param *);
2198 extern int sched_setscheduler_nocheck(struct task_struct *, int,
2199 				      const struct sched_param *);
2200 extern int sched_setattr(struct task_struct *,
2201 			 const struct sched_attr *);
2202 extern struct task_struct *idle_task(int cpu);
2203 /**
2204  * is_idle_task - is the specified task an idle task?
2205  * @p: the task in question.
2206  *
2207  * Return: 1 if @p is an idle task. 0 otherwise.
2208  */
2209 static inline bool is_idle_task(const struct task_struct *p)
2210 {
2211 	return p->pid == 0;
2212 }
2213 extern struct task_struct *curr_task(int cpu);
2214 extern void set_curr_task(int cpu, struct task_struct *p);
2215 
2216 void yield(void);
2217 
2218 /*
2219  * The default (Linux) execution domain.
2220  */
2221 extern struct exec_domain	default_exec_domain;
2222 
2223 union thread_union {
2224 	struct thread_info thread_info;
2225 	unsigned long stack[THREAD_SIZE/sizeof(long)];
2226 };
2227 
2228 #ifndef __HAVE_ARCH_KSTACK_END
2229 static inline int kstack_end(void *addr)
2230 {
2231 	/* Reliable end of stack detection:
2232 	 * Some APM bios versions misalign the stack
2233 	 */
2234 	return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
2235 }
2236 #endif
2237 
2238 extern union thread_union init_thread_union;
2239 extern struct task_struct init_task;
2240 
2241 extern struct   mm_struct init_mm;
2242 
2243 extern struct pid_namespace init_pid_ns;
2244 
2245 /*
2246  * find a task by one of its numerical ids
2247  *
2248  * find_task_by_pid_ns():
2249  *      finds a task by its pid in the specified namespace
2250  * find_task_by_vpid():
2251  *      finds a task by its virtual pid
2252  *
2253  * see also find_vpid() etc in include/linux/pid.h
2254  */
2255 
2256 extern struct task_struct *find_task_by_vpid(pid_t nr);
2257 extern struct task_struct *find_task_by_pid_ns(pid_t nr,
2258 		struct pid_namespace *ns);
2259 
2260 /* per-UID process charging. */
2261 extern struct user_struct * alloc_uid(kuid_t);
2262 static inline struct user_struct *get_uid(struct user_struct *u)
2263 {
2264 	atomic_inc(&u->__count);
2265 	return u;
2266 }
2267 extern void free_uid(struct user_struct *);
2268 
2269 #include <asm/current.h>
2270 
2271 extern void xtime_update(unsigned long ticks);
2272 
2273 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2274 extern int wake_up_process(struct task_struct *tsk);
2275 extern void wake_up_new_task(struct task_struct *tsk);
2276 #ifdef CONFIG_SMP
2277  extern void kick_process(struct task_struct *tsk);
2278 #else
2279  static inline void kick_process(struct task_struct *tsk) { }
2280 #endif
2281 extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
2282 extern void sched_dead(struct task_struct *p);
2283 
2284 extern void proc_caches_init(void);
2285 extern void flush_signals(struct task_struct *);
2286 extern void __flush_signals(struct task_struct *);
2287 extern void ignore_signals(struct task_struct *);
2288 extern void flush_signal_handlers(struct task_struct *, int force_default);
2289 extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
2290 
2291 static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
2292 {
2293 	unsigned long flags;
2294 	int ret;
2295 
2296 	spin_lock_irqsave(&tsk->sighand->siglock, flags);
2297 	ret = dequeue_signal(tsk, mask, info);
2298 	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
2299 
2300 	return ret;
2301 }
2302 
2303 extern void block_all_signals(int (*notifier)(void *priv), void *priv,
2304 			      sigset_t *mask);
2305 extern void unblock_all_signals(void);
2306 extern void release_task(struct task_struct * p);
2307 extern int send_sig_info(int, struct siginfo *, struct task_struct *);
2308 extern int force_sigsegv(int, struct task_struct *);
2309 extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2310 extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
2311 extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2312 extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *,
2313 				const struct cred *, u32);
2314 extern int kill_pgrp(struct pid *pid, int sig, int priv);
2315 extern int kill_pid(struct pid *pid, int sig, int priv);
2316 extern int kill_proc_info(int, struct siginfo *, pid_t);
2317 extern __must_check bool do_notify_parent(struct task_struct *, int);
2318 extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
2319 extern void force_sig(int, struct task_struct *);
2320 extern int send_sig(int, struct task_struct *, int);
2321 extern int zap_other_threads(struct task_struct *p);
2322 extern struct sigqueue *sigqueue_alloc(void);
2323 extern void sigqueue_free(struct sigqueue *);
2324 extern int send_sigqueue(struct sigqueue *,  struct task_struct *, int group);
2325 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
2326 
2327 static inline void restore_saved_sigmask(void)
2328 {
2329 	if (test_and_clear_restore_sigmask())
2330 		__set_current_blocked(&current->saved_sigmask);
2331 }
2332 
2333 static inline sigset_t *sigmask_to_save(void)
2334 {
2335 	sigset_t *res = &current->blocked;
2336 	if (unlikely(test_restore_sigmask()))
2337 		res = &current->saved_sigmask;
2338 	return res;
2339 }
2340 
2341 static inline int kill_cad_pid(int sig, int priv)
2342 {
2343 	return kill_pid(cad_pid, sig, priv);
2344 }
2345 
2346 /* These can be the second arg to send_sig_info/send_group_sig_info.  */
2347 #define SEND_SIG_NOINFO ((struct siginfo *) 0)
2348 #define SEND_SIG_PRIV	((struct siginfo *) 1)
2349 #define SEND_SIG_FORCED	((struct siginfo *) 2)
2350 
2351 /*
2352  * True if we are on the alternate signal stack.
2353  */
2354 static inline int on_sig_stack(unsigned long sp)
2355 {
2356 #ifdef CONFIG_STACK_GROWSUP
2357 	return sp >= current->sas_ss_sp &&
2358 		sp - current->sas_ss_sp < current->sas_ss_size;
2359 #else
2360 	return sp > current->sas_ss_sp &&
2361 		sp - current->sas_ss_sp <= current->sas_ss_size;
2362 #endif
2363 }
2364 
2365 static inline int sas_ss_flags(unsigned long sp)
2366 {
2367 	return (current->sas_ss_size == 0 ? SS_DISABLE
2368 		: on_sig_stack(sp) ? SS_ONSTACK : 0);
2369 }
2370 
2371 static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig)
2372 {
2373 	if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))
2374 #ifdef CONFIG_STACK_GROWSUP
2375 		return current->sas_ss_sp;
2376 #else
2377 		return current->sas_ss_sp + current->sas_ss_size;
2378 #endif
2379 	return sp;
2380 }
2381 
2382 /*
2383  * Routines for handling mm_structs
2384  */
2385 extern struct mm_struct * mm_alloc(void);
2386 
2387 /* mmdrop drops the mm and the page tables */
2388 extern void __mmdrop(struct mm_struct *);
2389 static inline void mmdrop(struct mm_struct * mm)
2390 {
2391 	if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2392 		__mmdrop(mm);
2393 }
2394 
2395 /* mmput gets rid of the mappings and all user-space */
2396 extern void mmput(struct mm_struct *);
2397 /* Grab a reference to a task's mm, if it is not already going away */
2398 extern struct mm_struct *get_task_mm(struct task_struct *task);
2399 /*
2400  * Grab a reference to a task's mm, if it is not already going away
2401  * and ptrace_may_access with the mode parameter passed to it
2402  * succeeds.
2403  */
2404 extern struct mm_struct *mm_access(struct task_struct *task, unsigned int mode);
2405 /* Remove the current tasks stale references to the old mm_struct */
2406 extern void mm_release(struct task_struct *, struct mm_struct *);
2407 
2408 extern int copy_thread(unsigned long, unsigned long, unsigned long,
2409 			struct task_struct *);
2410 extern void flush_thread(void);
2411 extern void exit_thread(void);
2412 
2413 extern void exit_files(struct task_struct *);
2414 extern void __cleanup_sighand(struct sighand_struct *);
2415 
2416 extern void exit_itimers(struct signal_struct *);
2417 extern void flush_itimer_signals(void);
2418 
2419 extern void do_group_exit(int);
2420 
2421 extern int do_execve(struct filename *,
2422 		     const char __user * const __user *,
2423 		     const char __user * const __user *);
2424 extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
2425 struct task_struct *fork_idle(int);
2426 extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
2427 
2428 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
2429 static inline void set_task_comm(struct task_struct *tsk, const char *from)
2430 {
2431 	__set_task_comm(tsk, from, false);
2432 }
2433 extern char *get_task_comm(char *to, struct task_struct *tsk);
2434 
2435 #ifdef CONFIG_SMP
2436 void scheduler_ipi(void);
2437 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
2438 #else
2439 static inline void scheduler_ipi(void) { }
2440 static inline unsigned long wait_task_inactive(struct task_struct *p,
2441 					       long match_state)
2442 {
2443 	return 1;
2444 }
2445 #endif
2446 
2447 #define next_task(p) \
2448 	list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
2449 
2450 #define for_each_process(p) \
2451 	for (p = &init_task ; (p = next_task(p)) != &init_task ; )
2452 
2453 extern bool current_is_single_threaded(void);
2454 
2455 /*
2456  * Careful: do_each_thread/while_each_thread is a double loop so
2457  *          'break' will not work as expected - use goto instead.
2458  */
2459 #define do_each_thread(g, t) \
2460 	for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
2461 
2462 #define while_each_thread(g, t) \
2463 	while ((t = next_thread(t)) != g)
2464 
2465 #define __for_each_thread(signal, t)	\
2466 	list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node)
2467 
2468 #define for_each_thread(p, t)		\
2469 	__for_each_thread((p)->signal, t)
2470 
2471 /* Careful: this is a double loop, 'break' won't work as expected. */
2472 #define for_each_process_thread(p, t)	\
2473 	for_each_process(p) for_each_thread(p, t)
2474 
2475 static inline int get_nr_threads(struct task_struct *tsk)
2476 {
2477 	return tsk->signal->nr_threads;
2478 }
2479 
2480 static inline bool thread_group_leader(struct task_struct *p)
2481 {
2482 	return p->exit_signal >= 0;
2483 }
2484 
2485 /* Do to the insanities of de_thread it is possible for a process
2486  * to have the pid of the thread group leader without actually being
2487  * the thread group leader.  For iteration through the pids in proc
2488  * all we care about is that we have a task with the appropriate
2489  * pid, we don't actually care if we have the right task.
2490  */
2491 static inline bool has_group_leader_pid(struct task_struct *p)
2492 {
2493 	return task_pid(p) == p->signal->leader_pid;
2494 }
2495 
2496 static inline
2497 bool same_thread_group(struct task_struct *p1, struct task_struct *p2)
2498 {
2499 	return p1->signal == p2->signal;
2500 }
2501 
2502 static inline struct task_struct *next_thread(const struct task_struct *p)
2503 {
2504 	return list_entry_rcu(p->thread_group.next,
2505 			      struct task_struct, thread_group);
2506 }
2507 
2508 static inline int thread_group_empty(struct task_struct *p)
2509 {
2510 	return list_empty(&p->thread_group);
2511 }
2512 
2513 #define delay_group_leader(p) \
2514 		(thread_group_leader(p) && !thread_group_empty(p))
2515 
2516 /*
2517  * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
2518  * subscriptions and synchronises with wait4().  Also used in procfs.  Also
2519  * pins the final release of task.io_context.  Also protects ->cpuset and
2520  * ->cgroup.subsys[]. And ->vfork_done.
2521  *
2522  * Nests both inside and outside of read_lock(&tasklist_lock).
2523  * It must not be nested with write_lock_irq(&tasklist_lock),
2524  * neither inside nor outside.
2525  */
2526 static inline void task_lock(struct task_struct *p)
2527 {
2528 	spin_lock(&p->alloc_lock);
2529 }
2530 
2531 static inline void task_unlock(struct task_struct *p)
2532 {
2533 	spin_unlock(&p->alloc_lock);
2534 }
2535 
2536 extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
2537 							unsigned long *flags);
2538 
2539 static inline struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
2540 						       unsigned long *flags)
2541 {
2542 	struct sighand_struct *ret;
2543 
2544 	ret = __lock_task_sighand(tsk, flags);
2545 	(void)__cond_lock(&tsk->sighand->siglock, ret);
2546 	return ret;
2547 }
2548 
2549 static inline void unlock_task_sighand(struct task_struct *tsk,
2550 						unsigned long *flags)
2551 {
2552 	spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
2553 }
2554 
2555 #ifdef CONFIG_CGROUPS
2556 static inline void threadgroup_change_begin(struct task_struct *tsk)
2557 {
2558 	down_read(&tsk->signal->group_rwsem);
2559 }
2560 static inline void threadgroup_change_end(struct task_struct *tsk)
2561 {
2562 	up_read(&tsk->signal->group_rwsem);
2563 }
2564 
2565 /**
2566  * threadgroup_lock - lock threadgroup
2567  * @tsk: member task of the threadgroup to lock
2568  *
2569  * Lock the threadgroup @tsk belongs to.  No new task is allowed to enter
2570  * and member tasks aren't allowed to exit (as indicated by PF_EXITING) or
2571  * change ->group_leader/pid.  This is useful for cases where the threadgroup
2572  * needs to stay stable across blockable operations.
2573  *
2574  * fork and exit paths explicitly call threadgroup_change_{begin|end}() for
2575  * synchronization.  While held, no new task will be added to threadgroup
2576  * and no existing live task will have its PF_EXITING set.
2577  *
2578  * de_thread() does threadgroup_change_{begin|end}() when a non-leader
2579  * sub-thread becomes a new leader.
2580  */
2581 static inline void threadgroup_lock(struct task_struct *tsk)
2582 {
2583 	down_write(&tsk->signal->group_rwsem);
2584 }
2585 
2586 /**
2587  * threadgroup_unlock - unlock threadgroup
2588  * @tsk: member task of the threadgroup to unlock
2589  *
2590  * Reverse threadgroup_lock().
2591  */
2592 static inline void threadgroup_unlock(struct task_struct *tsk)
2593 {
2594 	up_write(&tsk->signal->group_rwsem);
2595 }
2596 #else
2597 static inline void threadgroup_change_begin(struct task_struct *tsk) {}
2598 static inline void threadgroup_change_end(struct task_struct *tsk) {}
2599 static inline void threadgroup_lock(struct task_struct *tsk) {}
2600 static inline void threadgroup_unlock(struct task_struct *tsk) {}
2601 #endif
2602 
2603 #ifndef __HAVE_THREAD_FUNCTIONS
2604 
2605 #define task_thread_info(task)	((struct thread_info *)(task)->stack)
2606 #define task_stack_page(task)	((task)->stack)
2607 
2608 static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
2609 {
2610 	*task_thread_info(p) = *task_thread_info(org);
2611 	task_thread_info(p)->task = p;
2612 }
2613 
2614 static inline unsigned long *end_of_stack(struct task_struct *p)
2615 {
2616 	return (unsigned long *)(task_thread_info(p) + 1);
2617 }
2618 
2619 #endif
2620 
2621 static inline int object_is_on_stack(void *obj)
2622 {
2623 	void *stack = task_stack_page(current);
2624 
2625 	return (obj >= stack) && (obj < (stack + THREAD_SIZE));
2626 }
2627 
2628 extern void thread_info_cache_init(void);
2629 
2630 #ifdef CONFIG_DEBUG_STACK_USAGE
2631 static inline unsigned long stack_not_used(struct task_struct *p)
2632 {
2633 	unsigned long *n = end_of_stack(p);
2634 
2635 	do { 	/* Skip over canary */
2636 		n++;
2637 	} while (!*n);
2638 
2639 	return (unsigned long)n - (unsigned long)end_of_stack(p);
2640 }
2641 #endif
2642 
2643 /* set thread flags in other task's structures
2644  * - see asm/thread_info.h for TIF_xxxx flags available
2645  */
2646 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2647 {
2648 	set_ti_thread_flag(task_thread_info(tsk), flag);
2649 }
2650 
2651 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2652 {
2653 	clear_ti_thread_flag(task_thread_info(tsk), flag);
2654 }
2655 
2656 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2657 {
2658 	return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2659 }
2660 
2661 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2662 {
2663 	return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2664 }
2665 
2666 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2667 {
2668 	return test_ti_thread_flag(task_thread_info(tsk), flag);
2669 }
2670 
2671 static inline void set_tsk_need_resched(struct task_struct *tsk)
2672 {
2673 	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2674 }
2675 
2676 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2677 {
2678 	clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2679 }
2680 
2681 static inline int test_tsk_need_resched(struct task_struct *tsk)
2682 {
2683 	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2684 }
2685 
2686 static inline int restart_syscall(void)
2687 {
2688 	set_tsk_thread_flag(current, TIF_SIGPENDING);
2689 	return -ERESTARTNOINTR;
2690 }
2691 
2692 static inline int signal_pending(struct task_struct *p)
2693 {
2694 	return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
2695 }
2696 
2697 static inline int __fatal_signal_pending(struct task_struct *p)
2698 {
2699 	return unlikely(sigismember(&p->pending.signal, SIGKILL));
2700 }
2701 
2702 static inline int fatal_signal_pending(struct task_struct *p)
2703 {
2704 	return signal_pending(p) && __fatal_signal_pending(p);
2705 }
2706 
2707 static inline int signal_pending_state(long state, struct task_struct *p)
2708 {
2709 	if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
2710 		return 0;
2711 	if (!signal_pending(p))
2712 		return 0;
2713 
2714 	return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
2715 }
2716 
2717 /*
2718  * cond_resched() and cond_resched_lock(): latency reduction via
2719  * explicit rescheduling in places that are safe. The return
2720  * value indicates whether a reschedule was done in fact.
2721  * cond_resched_lock() will drop the spinlock before scheduling,
2722  * cond_resched_softirq() will enable bhs before scheduling.
2723  */
2724 extern int _cond_resched(void);
2725 
2726 #define cond_resched() ({			\
2727 	__might_sleep(__FILE__, __LINE__, 0);	\
2728 	_cond_resched();			\
2729 })
2730 
2731 extern int __cond_resched_lock(spinlock_t *lock);
2732 
2733 #ifdef CONFIG_PREEMPT_COUNT
2734 #define PREEMPT_LOCK_OFFSET	PREEMPT_OFFSET
2735 #else
2736 #define PREEMPT_LOCK_OFFSET	0
2737 #endif
2738 
2739 #define cond_resched_lock(lock) ({				\
2740 	__might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);	\
2741 	__cond_resched_lock(lock);				\
2742 })
2743 
2744 extern int __cond_resched_softirq(void);
2745 
2746 #define cond_resched_softirq() ({					\
2747 	__might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET);	\
2748 	__cond_resched_softirq();					\
2749 })
2750 
2751 static inline void cond_resched_rcu(void)
2752 {
2753 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
2754 	rcu_read_unlock();
2755 	cond_resched();
2756 	rcu_read_lock();
2757 #endif
2758 }
2759 
2760 /*
2761  * Does a critical section need to be broken due to another
2762  * task waiting?: (technically does not depend on CONFIG_PREEMPT,
2763  * but a general need for low latency)
2764  */
2765 static inline int spin_needbreak(spinlock_t *lock)
2766 {
2767 #ifdef CONFIG_PREEMPT
2768 	return spin_is_contended(lock);
2769 #else
2770 	return 0;
2771 #endif
2772 }
2773 
2774 /*
2775  * Idle thread specific functions to determine the need_resched
2776  * polling state.
2777  */
2778 #ifdef TIF_POLLING_NRFLAG
2779 static inline int tsk_is_polling(struct task_struct *p)
2780 {
2781 	return test_tsk_thread_flag(p, TIF_POLLING_NRFLAG);
2782 }
2783 
2784 static inline void __current_set_polling(void)
2785 {
2786 	set_thread_flag(TIF_POLLING_NRFLAG);
2787 }
2788 
2789 static inline bool __must_check current_set_polling_and_test(void)
2790 {
2791 	__current_set_polling();
2792 
2793 	/*
2794 	 * Polling state must be visible before we test NEED_RESCHED,
2795 	 * paired by resched_curr()
2796 	 */
2797 	smp_mb__after_atomic();
2798 
2799 	return unlikely(tif_need_resched());
2800 }
2801 
2802 static inline void __current_clr_polling(void)
2803 {
2804 	clear_thread_flag(TIF_POLLING_NRFLAG);
2805 }
2806 
2807 static inline bool __must_check current_clr_polling_and_test(void)
2808 {
2809 	__current_clr_polling();
2810 
2811 	/*
2812 	 * Polling state must be visible before we test NEED_RESCHED,
2813 	 * paired by resched_curr()
2814 	 */
2815 	smp_mb__after_atomic();
2816 
2817 	return unlikely(tif_need_resched());
2818 }
2819 
2820 #else
2821 static inline int tsk_is_polling(struct task_struct *p) { return 0; }
2822 static inline void __current_set_polling(void) { }
2823 static inline void __current_clr_polling(void) { }
2824 
2825 static inline bool __must_check current_set_polling_and_test(void)
2826 {
2827 	return unlikely(tif_need_resched());
2828 }
2829 static inline bool __must_check current_clr_polling_and_test(void)
2830 {
2831 	return unlikely(tif_need_resched());
2832 }
2833 #endif
2834 
2835 static inline void current_clr_polling(void)
2836 {
2837 	__current_clr_polling();
2838 
2839 	/*
2840 	 * Ensure we check TIF_NEED_RESCHED after we clear the polling bit.
2841 	 * Once the bit is cleared, we'll get IPIs with every new
2842 	 * TIF_NEED_RESCHED and the IPI handler, scheduler_ipi(), will also
2843 	 * fold.
2844 	 */
2845 	smp_mb(); /* paired with resched_curr() */
2846 
2847 	preempt_fold_need_resched();
2848 }
2849 
2850 static __always_inline bool need_resched(void)
2851 {
2852 	return unlikely(tif_need_resched());
2853 }
2854 
2855 /*
2856  * Thread group CPU time accounting.
2857  */
2858 void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
2859 void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
2860 
2861 static inline void thread_group_cputime_init(struct signal_struct *sig)
2862 {
2863 	raw_spin_lock_init(&sig->cputimer.lock);
2864 }
2865 
2866 /*
2867  * Reevaluate whether the task has signals pending delivery.
2868  * Wake the task if so.
2869  * This is required every time the blocked sigset_t changes.
2870  * callers must hold sighand->siglock.
2871  */
2872 extern void recalc_sigpending_and_wake(struct task_struct *t);
2873 extern void recalc_sigpending(void);
2874 
2875 extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
2876 
2877 static inline void signal_wake_up(struct task_struct *t, bool resume)
2878 {
2879 	signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0);
2880 }
2881 static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
2882 {
2883 	signal_wake_up_state(t, resume ? __TASK_TRACED : 0);
2884 }
2885 
2886 /*
2887  * Wrappers for p->thread_info->cpu access. No-op on UP.
2888  */
2889 #ifdef CONFIG_SMP
2890 
2891 static inline unsigned int task_cpu(const struct task_struct *p)
2892 {
2893 	return task_thread_info(p)->cpu;
2894 }
2895 
2896 static inline int task_node(const struct task_struct *p)
2897 {
2898 	return cpu_to_node(task_cpu(p));
2899 }
2900 
2901 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2902 
2903 #else
2904 
2905 static inline unsigned int task_cpu(const struct task_struct *p)
2906 {
2907 	return 0;
2908 }
2909 
2910 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2911 {
2912 }
2913 
2914 #endif /* CONFIG_SMP */
2915 
2916 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2917 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2918 
2919 #ifdef CONFIG_CGROUP_SCHED
2920 extern struct task_group root_task_group;
2921 #endif /* CONFIG_CGROUP_SCHED */
2922 
2923 extern int task_can_switch_user(struct user_struct *up,
2924 					struct task_struct *tsk);
2925 
2926 #ifdef CONFIG_TASK_XACCT
2927 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2928 {
2929 	tsk->ioac.rchar += amt;
2930 }
2931 
2932 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2933 {
2934 	tsk->ioac.wchar += amt;
2935 }
2936 
2937 static inline void inc_syscr(struct task_struct *tsk)
2938 {
2939 	tsk->ioac.syscr++;
2940 }
2941 
2942 static inline void inc_syscw(struct task_struct *tsk)
2943 {
2944 	tsk->ioac.syscw++;
2945 }
2946 #else
2947 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2948 {
2949 }
2950 
2951 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2952 {
2953 }
2954 
2955 static inline void inc_syscr(struct task_struct *tsk)
2956 {
2957 }
2958 
2959 static inline void inc_syscw(struct task_struct *tsk)
2960 {
2961 }
2962 #endif
2963 
2964 #ifndef TASK_SIZE_OF
2965 #define TASK_SIZE_OF(tsk)	TASK_SIZE
2966 #endif
2967 
2968 #ifdef CONFIG_MEMCG
2969 extern void mm_update_next_owner(struct mm_struct *mm);
2970 extern void mm_init_owner(struct mm_struct *mm, struct task_struct *p);
2971 #else
2972 static inline void mm_update_next_owner(struct mm_struct *mm)
2973 {
2974 }
2975 
2976 static inline void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
2977 {
2978 }
2979 #endif /* CONFIG_MEMCG */
2980 
2981 static inline unsigned long task_rlimit(const struct task_struct *tsk,
2982 		unsigned int limit)
2983 {
2984 	return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_cur);
2985 }
2986 
2987 static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
2988 		unsigned int limit)
2989 {
2990 	return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_max);
2991 }
2992 
2993 static inline unsigned long rlimit(unsigned int limit)
2994 {
2995 	return task_rlimit(current, limit);
2996 }
2997 
2998 static inline unsigned long rlimit_max(unsigned int limit)
2999 {
3000 	return task_rlimit_max(current, limit);
3001 }
3002 
3003 #endif
3004