xref: /linux-6.15/include/linux/sched.h (revision fe2a1bb1)
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/shm.h>
37 #include <linux/signal.h>
38 #include <linux/compiler.h>
39 #include <linux/completion.h>
40 #include <linux/pid.h>
41 #include <linux/percpu.h>
42 #include <linux/topology.h>
43 #include <linux/proportions.h>
44 #include <linux/seccomp.h>
45 #include <linux/rcupdate.h>
46 #include <linux/rculist.h>
47 #include <linux/rtmutex.h>
48 
49 #include <linux/time.h>
50 #include <linux/param.h>
51 #include <linux/resource.h>
52 #include <linux/timer.h>
53 #include <linux/hrtimer.h>
54 #include <linux/task_io_accounting.h>
55 #include <linux/latencytop.h>
56 #include <linux/cred.h>
57 #include <linux/llist.h>
58 #include <linux/uidgid.h>
59 #include <linux/gfp.h>
60 
61 #include <asm/processor.h>
62 
63 #define SCHED_ATTR_SIZE_VER0	48	/* sizeof first published struct */
64 
65 /*
66  * Extended scheduling parameters data structure.
67  *
68  * This is needed because the original struct sched_param can not be
69  * altered without introducing ABI issues with legacy applications
70  * (e.g., in sched_getparam()).
71  *
72  * However, the possibility of specifying more than just a priority for
73  * the tasks may be useful for a wide variety of application fields, e.g.,
74  * multimedia, streaming, automation and control, and many others.
75  *
76  * This variant (sched_attr) is meant at describing a so-called
77  * sporadic time-constrained task. In such model a task is specified by:
78  *  - the activation period or minimum instance inter-arrival time;
79  *  - the maximum (or average, depending on the actual scheduling
80  *    discipline) computation time of all instances, a.k.a. runtime;
81  *  - the deadline (relative to the actual activation time) of each
82  *    instance.
83  * Very briefly, a periodic (sporadic) task asks for the execution of
84  * some specific computation --which is typically called an instance--
85  * (at most) every period. Moreover, each instance typically lasts no more
86  * than the runtime and must be completed by time instant t equal to
87  * the instance activation time + the deadline.
88  *
89  * This is reflected by the actual fields of the sched_attr structure:
90  *
91  *  @size		size of the structure, for fwd/bwd compat.
92  *
93  *  @sched_policy	task's scheduling policy
94  *  @sched_flags	for customizing the scheduler behaviour
95  *  @sched_nice		task's nice value      (SCHED_NORMAL/BATCH)
96  *  @sched_priority	task's static priority (SCHED_FIFO/RR)
97  *  @sched_deadline	representative of the task's deadline
98  *  @sched_runtime	representative of the task's runtime
99  *  @sched_period	representative of the task's period
100  *
101  * Given this task model, there are a multiplicity of scheduling algorithms
102  * and policies, that can be used to ensure all the tasks will make their
103  * timing constraints.
104  *
105  * As of now, the SCHED_DEADLINE policy (sched_dl scheduling class) is the
106  * only user of this new interface. More information about the algorithm
107  * available in the scheduling class file or in Documentation/.
108  */
109 struct sched_attr {
110 	u32 size;
111 
112 	u32 sched_policy;
113 	u64 sched_flags;
114 
115 	/* SCHED_NORMAL, SCHED_BATCH */
116 	s32 sched_nice;
117 
118 	/* SCHED_FIFO, SCHED_RR */
119 	u32 sched_priority;
120 
121 	/* SCHED_DEADLINE */
122 	u64 sched_runtime;
123 	u64 sched_deadline;
124 	u64 sched_period;
125 };
126 
127 struct exec_domain;
128 struct futex_pi_state;
129 struct robust_list_head;
130 struct bio_list;
131 struct fs_struct;
132 struct perf_event_context;
133 struct blk_plug;
134 struct filename;
135 
136 #define VMACACHE_BITS 2
137 #define VMACACHE_SIZE (1U << VMACACHE_BITS)
138 #define VMACACHE_MASK (VMACACHE_SIZE - 1)
139 
140 /*
141  * These are the constant used to fake the fixed-point load-average
142  * counting. Some notes:
143  *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
144  *    a load-average precision of 10 bits integer + 11 bits fractional
145  *  - if you want to count load-averages more often, you need more
146  *    precision, or rounding will get you. With 2-second counting freq,
147  *    the EXP_n values would be 1981, 2034 and 2043 if still using only
148  *    11 bit fractions.
149  */
150 extern unsigned long avenrun[];		/* Load averages */
151 extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
152 
153 #define FSHIFT		11		/* nr of bits of precision */
154 #define FIXED_1		(1<<FSHIFT)	/* 1.0 as fixed-point */
155 #define LOAD_FREQ	(5*HZ+1)	/* 5 sec intervals */
156 #define EXP_1		1884		/* 1/exp(5sec/1min) as fixed-point */
157 #define EXP_5		2014		/* 1/exp(5sec/5min) */
158 #define EXP_15		2037		/* 1/exp(5sec/15min) */
159 
160 #define CALC_LOAD(load,exp,n) \
161 	load *= exp; \
162 	load += n*(FIXED_1-exp); \
163 	load >>= FSHIFT;
164 
165 extern unsigned long total_forks;
166 extern int nr_threads;
167 DECLARE_PER_CPU(unsigned long, process_counts);
168 extern int nr_processes(void);
169 extern unsigned long nr_running(void);
170 extern unsigned long nr_iowait(void);
171 extern unsigned long nr_iowait_cpu(int cpu);
172 extern void get_iowait_load(unsigned long *nr_waiters, unsigned long *load);
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 	struct sysv_shm sysvshm;
1389 #endif
1390 #ifdef CONFIG_DETECT_HUNG_TASK
1391 /* hung task detection */
1392 	unsigned long last_switch_count;
1393 #endif
1394 /* CPU-specific state of this task */
1395 	struct thread_struct thread;
1396 /* filesystem information */
1397 	struct fs_struct *fs;
1398 /* open file information */
1399 	struct files_struct *files;
1400 /* namespaces */
1401 	struct nsproxy *nsproxy;
1402 /* signal handlers */
1403 	struct signal_struct *signal;
1404 	struct sighand_struct *sighand;
1405 
1406 	sigset_t blocked, real_blocked;
1407 	sigset_t saved_sigmask;	/* restored if set_restore_sigmask() was used */
1408 	struct sigpending pending;
1409 
1410 	unsigned long sas_ss_sp;
1411 	size_t sas_ss_size;
1412 	int (*notifier)(void *priv);
1413 	void *notifier_data;
1414 	sigset_t *notifier_mask;
1415 	struct callback_head *task_works;
1416 
1417 	struct audit_context *audit_context;
1418 #ifdef CONFIG_AUDITSYSCALL
1419 	kuid_t loginuid;
1420 	unsigned int sessionid;
1421 #endif
1422 	struct seccomp seccomp;
1423 
1424 /* Thread group tracking */
1425    	u32 parent_exec_id;
1426    	u32 self_exec_id;
1427 /* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1428  * mempolicy */
1429 	spinlock_t alloc_lock;
1430 
1431 	/* Protection of the PI data structures: */
1432 	raw_spinlock_t pi_lock;
1433 
1434 #ifdef CONFIG_RT_MUTEXES
1435 	/* PI waiters blocked on a rt_mutex held by this task */
1436 	struct rb_root pi_waiters;
1437 	struct rb_node *pi_waiters_leftmost;
1438 	/* Deadlock detection and priority inheritance handling */
1439 	struct rt_mutex_waiter *pi_blocked_on;
1440 #endif
1441 
1442 #ifdef CONFIG_DEBUG_MUTEXES
1443 	/* mutex deadlock detection */
1444 	struct mutex_waiter *blocked_on;
1445 #endif
1446 #ifdef CONFIG_TRACE_IRQFLAGS
1447 	unsigned int irq_events;
1448 	unsigned long hardirq_enable_ip;
1449 	unsigned long hardirq_disable_ip;
1450 	unsigned int hardirq_enable_event;
1451 	unsigned int hardirq_disable_event;
1452 	int hardirqs_enabled;
1453 	int hardirq_context;
1454 	unsigned long softirq_disable_ip;
1455 	unsigned long softirq_enable_ip;
1456 	unsigned int softirq_disable_event;
1457 	unsigned int softirq_enable_event;
1458 	int softirqs_enabled;
1459 	int softirq_context;
1460 #endif
1461 #ifdef CONFIG_LOCKDEP
1462 # define MAX_LOCK_DEPTH 48UL
1463 	u64 curr_chain_key;
1464 	int lockdep_depth;
1465 	unsigned int lockdep_recursion;
1466 	struct held_lock held_locks[MAX_LOCK_DEPTH];
1467 	gfp_t lockdep_reclaim_gfp;
1468 #endif
1469 
1470 /* journalling filesystem info */
1471 	void *journal_info;
1472 
1473 /* stacked block device info */
1474 	struct bio_list *bio_list;
1475 
1476 #ifdef CONFIG_BLOCK
1477 /* stack plugging */
1478 	struct blk_plug *plug;
1479 #endif
1480 
1481 /* VM state */
1482 	struct reclaim_state *reclaim_state;
1483 
1484 	struct backing_dev_info *backing_dev_info;
1485 
1486 	struct io_context *io_context;
1487 
1488 	unsigned long ptrace_message;
1489 	siginfo_t *last_siginfo; /* For ptrace use.  */
1490 	struct task_io_accounting ioac;
1491 #if defined(CONFIG_TASK_XACCT)
1492 	u64 acct_rss_mem1;	/* accumulated rss usage */
1493 	u64 acct_vm_mem1;	/* accumulated virtual memory usage */
1494 	cputime_t acct_timexpd;	/* stime + utime since last update */
1495 #endif
1496 #ifdef CONFIG_CPUSETS
1497 	nodemask_t mems_allowed;	/* Protected by alloc_lock */
1498 	seqcount_t mems_allowed_seq;	/* Seqence no to catch updates */
1499 	int cpuset_mem_spread_rotor;
1500 	int cpuset_slab_spread_rotor;
1501 #endif
1502 #ifdef CONFIG_CGROUPS
1503 	/* Control Group info protected by css_set_lock */
1504 	struct css_set __rcu *cgroups;
1505 	/* cg_list protected by css_set_lock and tsk->alloc_lock */
1506 	struct list_head cg_list;
1507 #endif
1508 #ifdef CONFIG_FUTEX
1509 	struct robust_list_head __user *robust_list;
1510 #ifdef CONFIG_COMPAT
1511 	struct compat_robust_list_head __user *compat_robust_list;
1512 #endif
1513 	struct list_head pi_state_list;
1514 	struct futex_pi_state *pi_state_cache;
1515 #endif
1516 #ifdef CONFIG_PERF_EVENTS
1517 	struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1518 	struct mutex perf_event_mutex;
1519 	struct list_head perf_event_list;
1520 #endif
1521 #ifdef CONFIG_DEBUG_PREEMPT
1522 	unsigned long preempt_disable_ip;
1523 #endif
1524 #ifdef CONFIG_NUMA
1525 	struct mempolicy *mempolicy;	/* Protected by alloc_lock */
1526 	short il_next;
1527 	short pref_node_fork;
1528 #endif
1529 #ifdef CONFIG_NUMA_BALANCING
1530 	int numa_scan_seq;
1531 	unsigned int numa_scan_period;
1532 	unsigned int numa_scan_period_max;
1533 	int numa_preferred_nid;
1534 	unsigned long numa_migrate_retry;
1535 	u64 node_stamp;			/* migration stamp  */
1536 	u64 last_task_numa_placement;
1537 	u64 last_sum_exec_runtime;
1538 	struct callback_head numa_work;
1539 
1540 	struct list_head numa_entry;
1541 	struct numa_group *numa_group;
1542 
1543 	/*
1544 	 * Exponential decaying average of faults on a per-node basis.
1545 	 * Scheduling placement decisions are made based on the these counts.
1546 	 * The values remain static for the duration of a PTE scan
1547 	 */
1548 	unsigned long *numa_faults_memory;
1549 	unsigned long total_numa_faults;
1550 
1551 	/*
1552 	 * numa_faults_buffer records faults per node during the current
1553 	 * scan window. When the scan completes, the counts in
1554 	 * numa_faults_memory decay and these values are copied.
1555 	 */
1556 	unsigned long *numa_faults_buffer_memory;
1557 
1558 	/*
1559 	 * Track the nodes the process was running on when a NUMA hinting
1560 	 * fault was incurred.
1561 	 */
1562 	unsigned long *numa_faults_cpu;
1563 	unsigned long *numa_faults_buffer_cpu;
1564 
1565 	/*
1566 	 * numa_faults_locality tracks if faults recorded during the last
1567 	 * scan window were remote/local. The task scan period is adapted
1568 	 * based on the locality of the faults with different weights
1569 	 * depending on whether they were shared or private faults
1570 	 */
1571 	unsigned long numa_faults_locality[2];
1572 
1573 	unsigned long numa_pages_migrated;
1574 #endif /* CONFIG_NUMA_BALANCING */
1575 
1576 	struct rcu_head rcu;
1577 
1578 	/*
1579 	 * cache last used pipe for splice
1580 	 */
1581 	struct pipe_inode_info *splice_pipe;
1582 
1583 	struct page_frag task_frag;
1584 
1585 #ifdef	CONFIG_TASK_DELAY_ACCT
1586 	struct task_delay_info *delays;
1587 #endif
1588 #ifdef CONFIG_FAULT_INJECTION
1589 	int make_it_fail;
1590 #endif
1591 	/*
1592 	 * when (nr_dirtied >= nr_dirtied_pause), it's time to call
1593 	 * balance_dirty_pages() for some dirty throttling pause
1594 	 */
1595 	int nr_dirtied;
1596 	int nr_dirtied_pause;
1597 	unsigned long dirty_paused_when; /* start of a write-and-pause period */
1598 
1599 #ifdef CONFIG_LATENCYTOP
1600 	int latency_record_count;
1601 	struct latency_record latency_record[LT_SAVECOUNT];
1602 #endif
1603 	/*
1604 	 * time slack values; these are used to round up poll() and
1605 	 * select() etc timeout values. These are in nanoseconds.
1606 	 */
1607 	unsigned long timer_slack_ns;
1608 	unsigned long default_timer_slack_ns;
1609 
1610 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1611 	/* Index of current stored address in ret_stack */
1612 	int curr_ret_stack;
1613 	/* Stack of return addresses for return function tracing */
1614 	struct ftrace_ret_stack	*ret_stack;
1615 	/* time stamp for last schedule */
1616 	unsigned long long ftrace_timestamp;
1617 	/*
1618 	 * Number of functions that haven't been traced
1619 	 * because of depth overrun.
1620 	 */
1621 	atomic_t trace_overrun;
1622 	/* Pause for the tracing */
1623 	atomic_t tracing_graph_pause;
1624 #endif
1625 #ifdef CONFIG_TRACING
1626 	/* state flags for use by tracers */
1627 	unsigned long trace;
1628 	/* bitmask and counter of trace recursion */
1629 	unsigned long trace_recursion;
1630 #endif /* CONFIG_TRACING */
1631 #ifdef CONFIG_MEMCG /* memcg uses this to do batch job */
1632 	unsigned int memcg_kmem_skip_account;
1633 	struct memcg_oom_info {
1634 		struct mem_cgroup *memcg;
1635 		gfp_t gfp_mask;
1636 		int order;
1637 		unsigned int may_oom:1;
1638 	} memcg_oom;
1639 #endif
1640 #ifdef CONFIG_UPROBES
1641 	struct uprobe_task *utask;
1642 #endif
1643 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1644 	unsigned int	sequential_io;
1645 	unsigned int	sequential_io_avg;
1646 #endif
1647 };
1648 
1649 /* Future-safe accessor for struct task_struct's cpus_allowed. */
1650 #define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
1651 
1652 #define TNF_MIGRATED	0x01
1653 #define TNF_NO_GROUP	0x02
1654 #define TNF_SHARED	0x04
1655 #define TNF_FAULT_LOCAL	0x08
1656 
1657 #ifdef CONFIG_NUMA_BALANCING
1658 extern void task_numa_fault(int last_node, int node, int pages, int flags);
1659 extern pid_t task_numa_group_id(struct task_struct *p);
1660 extern void set_numabalancing_state(bool enabled);
1661 extern void task_numa_free(struct task_struct *p);
1662 extern bool should_numa_migrate_memory(struct task_struct *p, struct page *page,
1663 					int src_nid, int dst_cpu);
1664 #else
1665 static inline void task_numa_fault(int last_node, int node, int pages,
1666 				   int flags)
1667 {
1668 }
1669 static inline pid_t task_numa_group_id(struct task_struct *p)
1670 {
1671 	return 0;
1672 }
1673 static inline void set_numabalancing_state(bool enabled)
1674 {
1675 }
1676 static inline void task_numa_free(struct task_struct *p)
1677 {
1678 }
1679 static inline bool should_numa_migrate_memory(struct task_struct *p,
1680 				struct page *page, int src_nid, int dst_cpu)
1681 {
1682 	return true;
1683 }
1684 #endif
1685 
1686 static inline struct pid *task_pid(struct task_struct *task)
1687 {
1688 	return task->pids[PIDTYPE_PID].pid;
1689 }
1690 
1691 static inline struct pid *task_tgid(struct task_struct *task)
1692 {
1693 	return task->group_leader->pids[PIDTYPE_PID].pid;
1694 }
1695 
1696 /*
1697  * Without tasklist or rcu lock it is not safe to dereference
1698  * the result of task_pgrp/task_session even if task == current,
1699  * we can race with another thread doing sys_setsid/sys_setpgid.
1700  */
1701 static inline struct pid *task_pgrp(struct task_struct *task)
1702 {
1703 	return task->group_leader->pids[PIDTYPE_PGID].pid;
1704 }
1705 
1706 static inline struct pid *task_session(struct task_struct *task)
1707 {
1708 	return task->group_leader->pids[PIDTYPE_SID].pid;
1709 }
1710 
1711 struct pid_namespace;
1712 
1713 /*
1714  * the helpers to get the task's different pids as they are seen
1715  * from various namespaces
1716  *
1717  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1718  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1719  *                     current.
1720  * task_xid_nr_ns()  : id seen from the ns specified;
1721  *
1722  * set_task_vxid()   : assigns a virtual id to a task;
1723  *
1724  * see also pid_nr() etc in include/linux/pid.h
1725  */
1726 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
1727 			struct pid_namespace *ns);
1728 
1729 static inline pid_t task_pid_nr(struct task_struct *tsk)
1730 {
1731 	return tsk->pid;
1732 }
1733 
1734 static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
1735 					struct pid_namespace *ns)
1736 {
1737 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1738 }
1739 
1740 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1741 {
1742 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1743 }
1744 
1745 
1746 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1747 {
1748 	return tsk->tgid;
1749 }
1750 
1751 pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1752 
1753 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1754 {
1755 	return pid_vnr(task_tgid(tsk));
1756 }
1757 
1758 
1759 static inline int pid_alive(const struct task_struct *p);
1760 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1761 {
1762 	pid_t pid = 0;
1763 
1764 	rcu_read_lock();
1765 	if (pid_alive(tsk))
1766 		pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1767 	rcu_read_unlock();
1768 
1769 	return pid;
1770 }
1771 
1772 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1773 {
1774 	return task_ppid_nr_ns(tsk, &init_pid_ns);
1775 }
1776 
1777 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
1778 					struct pid_namespace *ns)
1779 {
1780 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1781 }
1782 
1783 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1784 {
1785 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1786 }
1787 
1788 
1789 static inline pid_t task_session_nr_ns(struct task_struct *tsk,
1790 					struct pid_namespace *ns)
1791 {
1792 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1793 }
1794 
1795 static inline pid_t task_session_vnr(struct task_struct *tsk)
1796 {
1797 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1798 }
1799 
1800 /* obsolete, do not use */
1801 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1802 {
1803 	return task_pgrp_nr_ns(tsk, &init_pid_ns);
1804 }
1805 
1806 /**
1807  * pid_alive - check that a task structure is not stale
1808  * @p: Task structure to be checked.
1809  *
1810  * Test if a process is not yet dead (at most zombie state)
1811  * If pid_alive fails, then pointers within the task structure
1812  * can be stale and must not be dereferenced.
1813  *
1814  * Return: 1 if the process is alive. 0 otherwise.
1815  */
1816 static inline int pid_alive(const struct task_struct *p)
1817 {
1818 	return p->pids[PIDTYPE_PID].pid != NULL;
1819 }
1820 
1821 /**
1822  * is_global_init - check if a task structure is init
1823  * @tsk: Task structure to be checked.
1824  *
1825  * Check if a task structure is the first user space task the kernel created.
1826  *
1827  * Return: 1 if the task structure is init. 0 otherwise.
1828  */
1829 static inline int is_global_init(struct task_struct *tsk)
1830 {
1831 	return tsk->pid == 1;
1832 }
1833 
1834 extern struct pid *cad_pid;
1835 
1836 extern void free_task(struct task_struct *tsk);
1837 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
1838 
1839 extern void __put_task_struct(struct task_struct *t);
1840 
1841 static inline void put_task_struct(struct task_struct *t)
1842 {
1843 	if (atomic_dec_and_test(&t->usage))
1844 		__put_task_struct(t);
1845 }
1846 
1847 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1848 extern void task_cputime(struct task_struct *t,
1849 			 cputime_t *utime, cputime_t *stime);
1850 extern void task_cputime_scaled(struct task_struct *t,
1851 				cputime_t *utimescaled, cputime_t *stimescaled);
1852 extern cputime_t task_gtime(struct task_struct *t);
1853 #else
1854 static inline void task_cputime(struct task_struct *t,
1855 				cputime_t *utime, cputime_t *stime)
1856 {
1857 	if (utime)
1858 		*utime = t->utime;
1859 	if (stime)
1860 		*stime = t->stime;
1861 }
1862 
1863 static inline void task_cputime_scaled(struct task_struct *t,
1864 				       cputime_t *utimescaled,
1865 				       cputime_t *stimescaled)
1866 {
1867 	if (utimescaled)
1868 		*utimescaled = t->utimescaled;
1869 	if (stimescaled)
1870 		*stimescaled = t->stimescaled;
1871 }
1872 
1873 static inline cputime_t task_gtime(struct task_struct *t)
1874 {
1875 	return t->gtime;
1876 }
1877 #endif
1878 extern void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
1879 extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
1880 
1881 /*
1882  * Per process flags
1883  */
1884 #define PF_EXITING	0x00000004	/* getting shut down */
1885 #define PF_EXITPIDONE	0x00000008	/* pi exit done on shut down */
1886 #define PF_VCPU		0x00000010	/* I'm a virtual CPU */
1887 #define PF_WQ_WORKER	0x00000020	/* I'm a workqueue worker */
1888 #define PF_FORKNOEXEC	0x00000040	/* forked but didn't exec */
1889 #define PF_MCE_PROCESS  0x00000080      /* process policy on mce errors */
1890 #define PF_SUPERPRIV	0x00000100	/* used super-user privileges */
1891 #define PF_DUMPCORE	0x00000200	/* dumped core */
1892 #define PF_SIGNALED	0x00000400	/* killed by a signal */
1893 #define PF_MEMALLOC	0x00000800	/* Allocating memory */
1894 #define PF_NPROC_EXCEEDED 0x00001000	/* set_user noticed that RLIMIT_NPROC was exceeded */
1895 #define PF_USED_MATH	0x00002000	/* if unset the fpu must be initialized before use */
1896 #define PF_USED_ASYNC	0x00004000	/* used async_schedule*(), used by module init */
1897 #define PF_NOFREEZE	0x00008000	/* this thread should not be frozen */
1898 #define PF_FROZEN	0x00010000	/* frozen for system suspend */
1899 #define PF_FSTRANS	0x00020000	/* inside a filesystem transaction */
1900 #define PF_KSWAPD	0x00040000	/* I am kswapd */
1901 #define PF_MEMALLOC_NOIO 0x00080000	/* Allocating memory without IO involved */
1902 #define PF_LESS_THROTTLE 0x00100000	/* Throttle me less: I clean memory */
1903 #define PF_KTHREAD	0x00200000	/* I am a kernel thread */
1904 #define PF_RANDOMIZE	0x00400000	/* randomize virtual address space */
1905 #define PF_SWAPWRITE	0x00800000	/* Allowed to write to swap */
1906 #define PF_SPREAD_PAGE	0x01000000	/* Spread page cache over cpuset */
1907 #define PF_SPREAD_SLAB	0x02000000	/* Spread some slab caches over cpuset */
1908 #define PF_NO_SETAFFINITY 0x04000000	/* Userland is not allowed to meddle with cpus_allowed */
1909 #define PF_MCE_EARLY    0x08000000      /* Early kill for mce process policy */
1910 #define PF_MUTEX_TESTER	0x20000000	/* Thread belongs to the rt mutex tester */
1911 #define PF_FREEZER_SKIP	0x40000000	/* Freezer should not count it as freezable */
1912 #define PF_SUSPEND_TASK 0x80000000      /* this thread called freeze_processes and should not be frozen */
1913 
1914 /*
1915  * Only the _current_ task can read/write to tsk->flags, but other
1916  * tasks can access tsk->flags in readonly mode for example
1917  * with tsk_used_math (like during threaded core dumping).
1918  * There is however an exception to this rule during ptrace
1919  * or during fork: the ptracer task is allowed to write to the
1920  * child->flags of its traced child (same goes for fork, the parent
1921  * can write to the child->flags), because we're guaranteed the
1922  * child is not running and in turn not changing child->flags
1923  * at the same time the parent does it.
1924  */
1925 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1926 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1927 #define clear_used_math() clear_stopped_child_used_math(current)
1928 #define set_used_math() set_stopped_child_used_math(current)
1929 #define conditional_stopped_child_used_math(condition, child) \
1930 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1931 #define conditional_used_math(condition) \
1932 	conditional_stopped_child_used_math(condition, current)
1933 #define copy_to_stopped_child_used_math(child) \
1934 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1935 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1936 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1937 #define used_math() tsk_used_math(current)
1938 
1939 /* __GFP_IO isn't allowed if PF_MEMALLOC_NOIO is set in current->flags */
1940 static inline gfp_t memalloc_noio_flags(gfp_t flags)
1941 {
1942 	if (unlikely(current->flags & PF_MEMALLOC_NOIO))
1943 		flags &= ~__GFP_IO;
1944 	return flags;
1945 }
1946 
1947 static inline unsigned int memalloc_noio_save(void)
1948 {
1949 	unsigned int flags = current->flags & PF_MEMALLOC_NOIO;
1950 	current->flags |= PF_MEMALLOC_NOIO;
1951 	return flags;
1952 }
1953 
1954 static inline void memalloc_noio_restore(unsigned int flags)
1955 {
1956 	current->flags = (current->flags & ~PF_MEMALLOC_NOIO) | flags;
1957 }
1958 
1959 /* Per-process atomic flags. */
1960 #define PFA_NO_NEW_PRIVS 0x00000001	/* May not gain new privileges. */
1961 
1962 static inline bool task_no_new_privs(struct task_struct *p)
1963 {
1964 	return test_bit(PFA_NO_NEW_PRIVS, &p->atomic_flags);
1965 }
1966 
1967 static inline void task_set_no_new_privs(struct task_struct *p)
1968 {
1969 	set_bit(PFA_NO_NEW_PRIVS, &p->atomic_flags);
1970 }
1971 
1972 /*
1973  * task->jobctl flags
1974  */
1975 #define JOBCTL_STOP_SIGMASK	0xffff	/* signr of the last group stop */
1976 
1977 #define JOBCTL_STOP_DEQUEUED_BIT 16	/* stop signal dequeued */
1978 #define JOBCTL_STOP_PENDING_BIT	17	/* task should stop for group stop */
1979 #define JOBCTL_STOP_CONSUME_BIT	18	/* consume group stop count */
1980 #define JOBCTL_TRAP_STOP_BIT	19	/* trap for STOP */
1981 #define JOBCTL_TRAP_NOTIFY_BIT	20	/* trap for NOTIFY */
1982 #define JOBCTL_TRAPPING_BIT	21	/* switching to TRACED */
1983 #define JOBCTL_LISTENING_BIT	22	/* ptracer is listening for events */
1984 
1985 #define JOBCTL_STOP_DEQUEUED	(1 << JOBCTL_STOP_DEQUEUED_BIT)
1986 #define JOBCTL_STOP_PENDING	(1 << JOBCTL_STOP_PENDING_BIT)
1987 #define JOBCTL_STOP_CONSUME	(1 << JOBCTL_STOP_CONSUME_BIT)
1988 #define JOBCTL_TRAP_STOP	(1 << JOBCTL_TRAP_STOP_BIT)
1989 #define JOBCTL_TRAP_NOTIFY	(1 << JOBCTL_TRAP_NOTIFY_BIT)
1990 #define JOBCTL_TRAPPING		(1 << JOBCTL_TRAPPING_BIT)
1991 #define JOBCTL_LISTENING	(1 << JOBCTL_LISTENING_BIT)
1992 
1993 #define JOBCTL_TRAP_MASK	(JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
1994 #define JOBCTL_PENDING_MASK	(JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)
1995 
1996 extern bool task_set_jobctl_pending(struct task_struct *task,
1997 				    unsigned int mask);
1998 extern void task_clear_jobctl_trapping(struct task_struct *task);
1999 extern void task_clear_jobctl_pending(struct task_struct *task,
2000 				      unsigned int mask);
2001 
2002 #ifdef CONFIG_PREEMPT_RCU
2003 
2004 #define RCU_READ_UNLOCK_BLOCKED (1 << 0) /* blocked while in RCU read-side. */
2005 #define RCU_READ_UNLOCK_NEED_QS (1 << 1) /* RCU core needs CPU response. */
2006 
2007 static inline void rcu_copy_process(struct task_struct *p)
2008 {
2009 	p->rcu_read_lock_nesting = 0;
2010 	p->rcu_read_unlock_special = 0;
2011 #ifdef CONFIG_TREE_PREEMPT_RCU
2012 	p->rcu_blocked_node = NULL;
2013 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
2014 	INIT_LIST_HEAD(&p->rcu_node_entry);
2015 }
2016 
2017 #else
2018 
2019 static inline void rcu_copy_process(struct task_struct *p)
2020 {
2021 }
2022 
2023 #endif
2024 
2025 static inline void tsk_restore_flags(struct task_struct *task,
2026 				unsigned long orig_flags, unsigned long flags)
2027 {
2028 	task->flags &= ~flags;
2029 	task->flags |= orig_flags & flags;
2030 }
2031 
2032 #ifdef CONFIG_SMP
2033 extern void do_set_cpus_allowed(struct task_struct *p,
2034 			       const struct cpumask *new_mask);
2035 
2036 extern int set_cpus_allowed_ptr(struct task_struct *p,
2037 				const struct cpumask *new_mask);
2038 #else
2039 static inline void do_set_cpus_allowed(struct task_struct *p,
2040 				      const struct cpumask *new_mask)
2041 {
2042 }
2043 static inline int set_cpus_allowed_ptr(struct task_struct *p,
2044 				       const struct cpumask *new_mask)
2045 {
2046 	if (!cpumask_test_cpu(0, new_mask))
2047 		return -EINVAL;
2048 	return 0;
2049 }
2050 #endif
2051 
2052 #ifdef CONFIG_NO_HZ_COMMON
2053 void calc_load_enter_idle(void);
2054 void calc_load_exit_idle(void);
2055 #else
2056 static inline void calc_load_enter_idle(void) { }
2057 static inline void calc_load_exit_idle(void) { }
2058 #endif /* CONFIG_NO_HZ_COMMON */
2059 
2060 #ifndef CONFIG_CPUMASK_OFFSTACK
2061 static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
2062 {
2063 	return set_cpus_allowed_ptr(p, &new_mask);
2064 }
2065 #endif
2066 
2067 /*
2068  * Do not use outside of architecture code which knows its limitations.
2069  *
2070  * sched_clock() has no promise of monotonicity or bounded drift between
2071  * CPUs, use (which you should not) requires disabling IRQs.
2072  *
2073  * Please use one of the three interfaces below.
2074  */
2075 extern unsigned long long notrace sched_clock(void);
2076 /*
2077  * See the comment in kernel/sched/clock.c
2078  */
2079 extern u64 cpu_clock(int cpu);
2080 extern u64 local_clock(void);
2081 extern u64 sched_clock_cpu(int cpu);
2082 
2083 
2084 extern void sched_clock_init(void);
2085 
2086 #ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
2087 static inline void sched_clock_tick(void)
2088 {
2089 }
2090 
2091 static inline void sched_clock_idle_sleep_event(void)
2092 {
2093 }
2094 
2095 static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
2096 {
2097 }
2098 #else
2099 /*
2100  * Architectures can set this to 1 if they have specified
2101  * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
2102  * but then during bootup it turns out that sched_clock()
2103  * is reliable after all:
2104  */
2105 extern int sched_clock_stable(void);
2106 extern void set_sched_clock_stable(void);
2107 extern void clear_sched_clock_stable(void);
2108 
2109 extern void sched_clock_tick(void);
2110 extern void sched_clock_idle_sleep_event(void);
2111 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2112 #endif
2113 
2114 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
2115 /*
2116  * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
2117  * The reason for this explicit opt-in is not to have perf penalty with
2118  * slow sched_clocks.
2119  */
2120 extern void enable_sched_clock_irqtime(void);
2121 extern void disable_sched_clock_irqtime(void);
2122 #else
2123 static inline void enable_sched_clock_irqtime(void) {}
2124 static inline void disable_sched_clock_irqtime(void) {}
2125 #endif
2126 
2127 extern unsigned long long
2128 task_sched_runtime(struct task_struct *task);
2129 
2130 /* sched_exec is called by processes performing an exec */
2131 #ifdef CONFIG_SMP
2132 extern void sched_exec(void);
2133 #else
2134 #define sched_exec()   {}
2135 #endif
2136 
2137 extern void sched_clock_idle_sleep_event(void);
2138 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2139 
2140 #ifdef CONFIG_HOTPLUG_CPU
2141 extern void idle_task_exit(void);
2142 #else
2143 static inline void idle_task_exit(void) {}
2144 #endif
2145 
2146 #if defined(CONFIG_NO_HZ_COMMON) && defined(CONFIG_SMP)
2147 extern void wake_up_nohz_cpu(int cpu);
2148 #else
2149 static inline void wake_up_nohz_cpu(int cpu) { }
2150 #endif
2151 
2152 #ifdef CONFIG_NO_HZ_FULL
2153 extern bool sched_can_stop_tick(void);
2154 extern u64 scheduler_tick_max_deferment(void);
2155 #else
2156 static inline bool sched_can_stop_tick(void) { return false; }
2157 #endif
2158 
2159 #ifdef CONFIG_SCHED_AUTOGROUP
2160 extern void sched_autogroup_create_attach(struct task_struct *p);
2161 extern void sched_autogroup_detach(struct task_struct *p);
2162 extern void sched_autogroup_fork(struct signal_struct *sig);
2163 extern void sched_autogroup_exit(struct signal_struct *sig);
2164 #ifdef CONFIG_PROC_FS
2165 extern void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m);
2166 extern int proc_sched_autogroup_set_nice(struct task_struct *p, int nice);
2167 #endif
2168 #else
2169 static inline void sched_autogroup_create_attach(struct task_struct *p) { }
2170 static inline void sched_autogroup_detach(struct task_struct *p) { }
2171 static inline void sched_autogroup_fork(struct signal_struct *sig) { }
2172 static inline void sched_autogroup_exit(struct signal_struct *sig) { }
2173 #endif
2174 
2175 extern int yield_to(struct task_struct *p, bool preempt);
2176 extern void set_user_nice(struct task_struct *p, long nice);
2177 extern int task_prio(const struct task_struct *p);
2178 /**
2179  * task_nice - return the nice value of a given task.
2180  * @p: the task in question.
2181  *
2182  * Return: The nice value [ -20 ... 0 ... 19 ].
2183  */
2184 static inline int task_nice(const struct task_struct *p)
2185 {
2186 	return PRIO_TO_NICE((p)->static_prio);
2187 }
2188 extern int can_nice(const struct task_struct *p, const int nice);
2189 extern int task_curr(const struct task_struct *p);
2190 extern int idle_cpu(int cpu);
2191 extern int sched_setscheduler(struct task_struct *, int,
2192 			      const struct sched_param *);
2193 extern int sched_setscheduler_nocheck(struct task_struct *, int,
2194 				      const struct sched_param *);
2195 extern int sched_setattr(struct task_struct *,
2196 			 const struct sched_attr *);
2197 extern struct task_struct *idle_task(int cpu);
2198 /**
2199  * is_idle_task - is the specified task an idle task?
2200  * @p: the task in question.
2201  *
2202  * Return: 1 if @p is an idle task. 0 otherwise.
2203  */
2204 static inline bool is_idle_task(const struct task_struct *p)
2205 {
2206 	return p->pid == 0;
2207 }
2208 extern struct task_struct *curr_task(int cpu);
2209 extern void set_curr_task(int cpu, struct task_struct *p);
2210 
2211 void yield(void);
2212 
2213 /*
2214  * The default (Linux) execution domain.
2215  */
2216 extern struct exec_domain	default_exec_domain;
2217 
2218 union thread_union {
2219 	struct thread_info thread_info;
2220 	unsigned long stack[THREAD_SIZE/sizeof(long)];
2221 };
2222 
2223 #ifndef __HAVE_ARCH_KSTACK_END
2224 static inline int kstack_end(void *addr)
2225 {
2226 	/* Reliable end of stack detection:
2227 	 * Some APM bios versions misalign the stack
2228 	 */
2229 	return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
2230 }
2231 #endif
2232 
2233 extern union thread_union init_thread_union;
2234 extern struct task_struct init_task;
2235 
2236 extern struct   mm_struct init_mm;
2237 
2238 extern struct pid_namespace init_pid_ns;
2239 
2240 /*
2241  * find a task by one of its numerical ids
2242  *
2243  * find_task_by_pid_ns():
2244  *      finds a task by its pid in the specified namespace
2245  * find_task_by_vpid():
2246  *      finds a task by its virtual pid
2247  *
2248  * see also find_vpid() etc in include/linux/pid.h
2249  */
2250 
2251 extern struct task_struct *find_task_by_vpid(pid_t nr);
2252 extern struct task_struct *find_task_by_pid_ns(pid_t nr,
2253 		struct pid_namespace *ns);
2254 
2255 /* per-UID process charging. */
2256 extern struct user_struct * alloc_uid(kuid_t);
2257 static inline struct user_struct *get_uid(struct user_struct *u)
2258 {
2259 	atomic_inc(&u->__count);
2260 	return u;
2261 }
2262 extern void free_uid(struct user_struct *);
2263 
2264 #include <asm/current.h>
2265 
2266 extern void xtime_update(unsigned long ticks);
2267 
2268 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2269 extern int wake_up_process(struct task_struct *tsk);
2270 extern void wake_up_new_task(struct task_struct *tsk);
2271 #ifdef CONFIG_SMP
2272  extern void kick_process(struct task_struct *tsk);
2273 #else
2274  static inline void kick_process(struct task_struct *tsk) { }
2275 #endif
2276 extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
2277 extern void sched_dead(struct task_struct *p);
2278 
2279 extern void proc_caches_init(void);
2280 extern void flush_signals(struct task_struct *);
2281 extern void __flush_signals(struct task_struct *);
2282 extern void ignore_signals(struct task_struct *);
2283 extern void flush_signal_handlers(struct task_struct *, int force_default);
2284 extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
2285 
2286 static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
2287 {
2288 	unsigned long flags;
2289 	int ret;
2290 
2291 	spin_lock_irqsave(&tsk->sighand->siglock, flags);
2292 	ret = dequeue_signal(tsk, mask, info);
2293 	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
2294 
2295 	return ret;
2296 }
2297 
2298 extern void block_all_signals(int (*notifier)(void *priv), void *priv,
2299 			      sigset_t *mask);
2300 extern void unblock_all_signals(void);
2301 extern void release_task(struct task_struct * p);
2302 extern int send_sig_info(int, struct siginfo *, struct task_struct *);
2303 extern int force_sigsegv(int, struct task_struct *);
2304 extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2305 extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
2306 extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2307 extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *,
2308 				const struct cred *, u32);
2309 extern int kill_pgrp(struct pid *pid, int sig, int priv);
2310 extern int kill_pid(struct pid *pid, int sig, int priv);
2311 extern int kill_proc_info(int, struct siginfo *, pid_t);
2312 extern __must_check bool do_notify_parent(struct task_struct *, int);
2313 extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
2314 extern void force_sig(int, struct task_struct *);
2315 extern int send_sig(int, struct task_struct *, int);
2316 extern int zap_other_threads(struct task_struct *p);
2317 extern struct sigqueue *sigqueue_alloc(void);
2318 extern void sigqueue_free(struct sigqueue *);
2319 extern int send_sigqueue(struct sigqueue *,  struct task_struct *, int group);
2320 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
2321 
2322 static inline void restore_saved_sigmask(void)
2323 {
2324 	if (test_and_clear_restore_sigmask())
2325 		__set_current_blocked(&current->saved_sigmask);
2326 }
2327 
2328 static inline sigset_t *sigmask_to_save(void)
2329 {
2330 	sigset_t *res = &current->blocked;
2331 	if (unlikely(test_restore_sigmask()))
2332 		res = &current->saved_sigmask;
2333 	return res;
2334 }
2335 
2336 static inline int kill_cad_pid(int sig, int priv)
2337 {
2338 	return kill_pid(cad_pid, sig, priv);
2339 }
2340 
2341 /* These can be the second arg to send_sig_info/send_group_sig_info.  */
2342 #define SEND_SIG_NOINFO ((struct siginfo *) 0)
2343 #define SEND_SIG_PRIV	((struct siginfo *) 1)
2344 #define SEND_SIG_FORCED	((struct siginfo *) 2)
2345 
2346 /*
2347  * True if we are on the alternate signal stack.
2348  */
2349 static inline int on_sig_stack(unsigned long sp)
2350 {
2351 #ifdef CONFIG_STACK_GROWSUP
2352 	return sp >= current->sas_ss_sp &&
2353 		sp - current->sas_ss_sp < current->sas_ss_size;
2354 #else
2355 	return sp > current->sas_ss_sp &&
2356 		sp - current->sas_ss_sp <= current->sas_ss_size;
2357 #endif
2358 }
2359 
2360 static inline int sas_ss_flags(unsigned long sp)
2361 {
2362 	if (!current->sas_ss_size)
2363 		return SS_DISABLE;
2364 
2365 	return on_sig_stack(sp) ? SS_ONSTACK : 0;
2366 }
2367 
2368 static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig)
2369 {
2370 	if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))
2371 #ifdef CONFIG_STACK_GROWSUP
2372 		return current->sas_ss_sp;
2373 #else
2374 		return current->sas_ss_sp + current->sas_ss_size;
2375 #endif
2376 	return sp;
2377 }
2378 
2379 /*
2380  * Routines for handling mm_structs
2381  */
2382 extern struct mm_struct * mm_alloc(void);
2383 
2384 /* mmdrop drops the mm and the page tables */
2385 extern void __mmdrop(struct mm_struct *);
2386 static inline void mmdrop(struct mm_struct * mm)
2387 {
2388 	if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2389 		__mmdrop(mm);
2390 }
2391 
2392 /* mmput gets rid of the mappings and all user-space */
2393 extern void mmput(struct mm_struct *);
2394 /* Grab a reference to a task's mm, if it is not already going away */
2395 extern struct mm_struct *get_task_mm(struct task_struct *task);
2396 /*
2397  * Grab a reference to a task's mm, if it is not already going away
2398  * and ptrace_may_access with the mode parameter passed to it
2399  * succeeds.
2400  */
2401 extern struct mm_struct *mm_access(struct task_struct *task, unsigned int mode);
2402 /* Remove the current tasks stale references to the old mm_struct */
2403 extern void mm_release(struct task_struct *, struct mm_struct *);
2404 
2405 extern int copy_thread(unsigned long, unsigned long, unsigned long,
2406 			struct task_struct *);
2407 extern void flush_thread(void);
2408 extern void exit_thread(void);
2409 
2410 extern void exit_files(struct task_struct *);
2411 extern void __cleanup_sighand(struct sighand_struct *);
2412 
2413 extern void exit_itimers(struct signal_struct *);
2414 extern void flush_itimer_signals(void);
2415 
2416 extern void do_group_exit(int);
2417 
2418 extern int do_execve(struct filename *,
2419 		     const char __user * const __user *,
2420 		     const char __user * const __user *);
2421 extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
2422 struct task_struct *fork_idle(int);
2423 extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
2424 
2425 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
2426 static inline void set_task_comm(struct task_struct *tsk, const char *from)
2427 {
2428 	__set_task_comm(tsk, from, false);
2429 }
2430 extern char *get_task_comm(char *to, struct task_struct *tsk);
2431 
2432 #ifdef CONFIG_SMP
2433 void scheduler_ipi(void);
2434 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
2435 #else
2436 static inline void scheduler_ipi(void) { }
2437 static inline unsigned long wait_task_inactive(struct task_struct *p,
2438 					       long match_state)
2439 {
2440 	return 1;
2441 }
2442 #endif
2443 
2444 #define next_task(p) \
2445 	list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
2446 
2447 #define for_each_process(p) \
2448 	for (p = &init_task ; (p = next_task(p)) != &init_task ; )
2449 
2450 extern bool current_is_single_threaded(void);
2451 
2452 /*
2453  * Careful: do_each_thread/while_each_thread is a double loop so
2454  *          'break' will not work as expected - use goto instead.
2455  */
2456 #define do_each_thread(g, t) \
2457 	for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
2458 
2459 #define while_each_thread(g, t) \
2460 	while ((t = next_thread(t)) != g)
2461 
2462 #define __for_each_thread(signal, t)	\
2463 	list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node)
2464 
2465 #define for_each_thread(p, t)		\
2466 	__for_each_thread((p)->signal, t)
2467 
2468 /* Careful: this is a double loop, 'break' won't work as expected. */
2469 #define for_each_process_thread(p, t)	\
2470 	for_each_process(p) for_each_thread(p, t)
2471 
2472 static inline int get_nr_threads(struct task_struct *tsk)
2473 {
2474 	return tsk->signal->nr_threads;
2475 }
2476 
2477 static inline bool thread_group_leader(struct task_struct *p)
2478 {
2479 	return p->exit_signal >= 0;
2480 }
2481 
2482 /* Do to the insanities of de_thread it is possible for a process
2483  * to have the pid of the thread group leader without actually being
2484  * the thread group leader.  For iteration through the pids in proc
2485  * all we care about is that we have a task with the appropriate
2486  * pid, we don't actually care if we have the right task.
2487  */
2488 static inline bool has_group_leader_pid(struct task_struct *p)
2489 {
2490 	return task_pid(p) == p->signal->leader_pid;
2491 }
2492 
2493 static inline
2494 bool same_thread_group(struct task_struct *p1, struct task_struct *p2)
2495 {
2496 	return p1->signal == p2->signal;
2497 }
2498 
2499 static inline struct task_struct *next_thread(const struct task_struct *p)
2500 {
2501 	return list_entry_rcu(p->thread_group.next,
2502 			      struct task_struct, thread_group);
2503 }
2504 
2505 static inline int thread_group_empty(struct task_struct *p)
2506 {
2507 	return list_empty(&p->thread_group);
2508 }
2509 
2510 #define delay_group_leader(p) \
2511 		(thread_group_leader(p) && !thread_group_empty(p))
2512 
2513 /*
2514  * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
2515  * subscriptions and synchronises with wait4().  Also used in procfs.  Also
2516  * pins the final release of task.io_context.  Also protects ->cpuset and
2517  * ->cgroup.subsys[]. And ->vfork_done.
2518  *
2519  * Nests both inside and outside of read_lock(&tasklist_lock).
2520  * It must not be nested with write_lock_irq(&tasklist_lock),
2521  * neither inside nor outside.
2522  */
2523 static inline void task_lock(struct task_struct *p)
2524 {
2525 	spin_lock(&p->alloc_lock);
2526 }
2527 
2528 static inline void task_unlock(struct task_struct *p)
2529 {
2530 	spin_unlock(&p->alloc_lock);
2531 }
2532 
2533 extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
2534 							unsigned long *flags);
2535 
2536 static inline struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
2537 						       unsigned long *flags)
2538 {
2539 	struct sighand_struct *ret;
2540 
2541 	ret = __lock_task_sighand(tsk, flags);
2542 	(void)__cond_lock(&tsk->sighand->siglock, ret);
2543 	return ret;
2544 }
2545 
2546 static inline void unlock_task_sighand(struct task_struct *tsk,
2547 						unsigned long *flags)
2548 {
2549 	spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
2550 }
2551 
2552 #ifdef CONFIG_CGROUPS
2553 static inline void threadgroup_change_begin(struct task_struct *tsk)
2554 {
2555 	down_read(&tsk->signal->group_rwsem);
2556 }
2557 static inline void threadgroup_change_end(struct task_struct *tsk)
2558 {
2559 	up_read(&tsk->signal->group_rwsem);
2560 }
2561 
2562 /**
2563  * threadgroup_lock - lock threadgroup
2564  * @tsk: member task of the threadgroup to lock
2565  *
2566  * Lock the threadgroup @tsk belongs to.  No new task is allowed to enter
2567  * and member tasks aren't allowed to exit (as indicated by PF_EXITING) or
2568  * change ->group_leader/pid.  This is useful for cases where the threadgroup
2569  * needs to stay stable across blockable operations.
2570  *
2571  * fork and exit paths explicitly call threadgroup_change_{begin|end}() for
2572  * synchronization.  While held, no new task will be added to threadgroup
2573  * and no existing live task will have its PF_EXITING set.
2574  *
2575  * de_thread() does threadgroup_change_{begin|end}() when a non-leader
2576  * sub-thread becomes a new leader.
2577  */
2578 static inline void threadgroup_lock(struct task_struct *tsk)
2579 {
2580 	down_write(&tsk->signal->group_rwsem);
2581 }
2582 
2583 /**
2584  * threadgroup_unlock - unlock threadgroup
2585  * @tsk: member task of the threadgroup to unlock
2586  *
2587  * Reverse threadgroup_lock().
2588  */
2589 static inline void threadgroup_unlock(struct task_struct *tsk)
2590 {
2591 	up_write(&tsk->signal->group_rwsem);
2592 }
2593 #else
2594 static inline void threadgroup_change_begin(struct task_struct *tsk) {}
2595 static inline void threadgroup_change_end(struct task_struct *tsk) {}
2596 static inline void threadgroup_lock(struct task_struct *tsk) {}
2597 static inline void threadgroup_unlock(struct task_struct *tsk) {}
2598 #endif
2599 
2600 #ifndef __HAVE_THREAD_FUNCTIONS
2601 
2602 #define task_thread_info(task)	((struct thread_info *)(task)->stack)
2603 #define task_stack_page(task)	((task)->stack)
2604 
2605 static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
2606 {
2607 	*task_thread_info(p) = *task_thread_info(org);
2608 	task_thread_info(p)->task = p;
2609 }
2610 
2611 static inline unsigned long *end_of_stack(struct task_struct *p)
2612 {
2613 	return (unsigned long *)(task_thread_info(p) + 1);
2614 }
2615 
2616 #endif
2617 
2618 static inline int object_is_on_stack(void *obj)
2619 {
2620 	void *stack = task_stack_page(current);
2621 
2622 	return (obj >= stack) && (obj < (stack + THREAD_SIZE));
2623 }
2624 
2625 extern void thread_info_cache_init(void);
2626 
2627 #ifdef CONFIG_DEBUG_STACK_USAGE
2628 static inline unsigned long stack_not_used(struct task_struct *p)
2629 {
2630 	unsigned long *n = end_of_stack(p);
2631 
2632 	do { 	/* Skip over canary */
2633 		n++;
2634 	} while (!*n);
2635 
2636 	return (unsigned long)n - (unsigned long)end_of_stack(p);
2637 }
2638 #endif
2639 
2640 /* set thread flags in other task's structures
2641  * - see asm/thread_info.h for TIF_xxxx flags available
2642  */
2643 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2644 {
2645 	set_ti_thread_flag(task_thread_info(tsk), flag);
2646 }
2647 
2648 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2649 {
2650 	clear_ti_thread_flag(task_thread_info(tsk), flag);
2651 }
2652 
2653 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2654 {
2655 	return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2656 }
2657 
2658 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2659 {
2660 	return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2661 }
2662 
2663 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2664 {
2665 	return test_ti_thread_flag(task_thread_info(tsk), flag);
2666 }
2667 
2668 static inline void set_tsk_need_resched(struct task_struct *tsk)
2669 {
2670 	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2671 }
2672 
2673 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2674 {
2675 	clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2676 }
2677 
2678 static inline int test_tsk_need_resched(struct task_struct *tsk)
2679 {
2680 	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2681 }
2682 
2683 static inline int restart_syscall(void)
2684 {
2685 	set_tsk_thread_flag(current, TIF_SIGPENDING);
2686 	return -ERESTARTNOINTR;
2687 }
2688 
2689 static inline int signal_pending(struct task_struct *p)
2690 {
2691 	return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
2692 }
2693 
2694 static inline int __fatal_signal_pending(struct task_struct *p)
2695 {
2696 	return unlikely(sigismember(&p->pending.signal, SIGKILL));
2697 }
2698 
2699 static inline int fatal_signal_pending(struct task_struct *p)
2700 {
2701 	return signal_pending(p) && __fatal_signal_pending(p);
2702 }
2703 
2704 static inline int signal_pending_state(long state, struct task_struct *p)
2705 {
2706 	if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
2707 		return 0;
2708 	if (!signal_pending(p))
2709 		return 0;
2710 
2711 	return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
2712 }
2713 
2714 /*
2715  * cond_resched() and cond_resched_lock(): latency reduction via
2716  * explicit rescheduling in places that are safe. The return
2717  * value indicates whether a reschedule was done in fact.
2718  * cond_resched_lock() will drop the spinlock before scheduling,
2719  * cond_resched_softirq() will enable bhs before scheduling.
2720  */
2721 extern int _cond_resched(void);
2722 
2723 #define cond_resched() ({			\
2724 	__might_sleep(__FILE__, __LINE__, 0);	\
2725 	_cond_resched();			\
2726 })
2727 
2728 extern int __cond_resched_lock(spinlock_t *lock);
2729 
2730 #ifdef CONFIG_PREEMPT_COUNT
2731 #define PREEMPT_LOCK_OFFSET	PREEMPT_OFFSET
2732 #else
2733 #define PREEMPT_LOCK_OFFSET	0
2734 #endif
2735 
2736 #define cond_resched_lock(lock) ({				\
2737 	__might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);	\
2738 	__cond_resched_lock(lock);				\
2739 })
2740 
2741 extern int __cond_resched_softirq(void);
2742 
2743 #define cond_resched_softirq() ({					\
2744 	__might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET);	\
2745 	__cond_resched_softirq();					\
2746 })
2747 
2748 static inline void cond_resched_rcu(void)
2749 {
2750 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
2751 	rcu_read_unlock();
2752 	cond_resched();
2753 	rcu_read_lock();
2754 #endif
2755 }
2756 
2757 /*
2758  * Does a critical section need to be broken due to another
2759  * task waiting?: (technically does not depend on CONFIG_PREEMPT,
2760  * but a general need for low latency)
2761  */
2762 static inline int spin_needbreak(spinlock_t *lock)
2763 {
2764 #ifdef CONFIG_PREEMPT
2765 	return spin_is_contended(lock);
2766 #else
2767 	return 0;
2768 #endif
2769 }
2770 
2771 /*
2772  * Idle thread specific functions to determine the need_resched
2773  * polling state.
2774  */
2775 #ifdef TIF_POLLING_NRFLAG
2776 static inline int tsk_is_polling(struct task_struct *p)
2777 {
2778 	return test_tsk_thread_flag(p, TIF_POLLING_NRFLAG);
2779 }
2780 
2781 static inline void __current_set_polling(void)
2782 {
2783 	set_thread_flag(TIF_POLLING_NRFLAG);
2784 }
2785 
2786 static inline bool __must_check current_set_polling_and_test(void)
2787 {
2788 	__current_set_polling();
2789 
2790 	/*
2791 	 * Polling state must be visible before we test NEED_RESCHED,
2792 	 * paired by resched_curr()
2793 	 */
2794 	smp_mb__after_atomic();
2795 
2796 	return unlikely(tif_need_resched());
2797 }
2798 
2799 static inline void __current_clr_polling(void)
2800 {
2801 	clear_thread_flag(TIF_POLLING_NRFLAG);
2802 }
2803 
2804 static inline bool __must_check current_clr_polling_and_test(void)
2805 {
2806 	__current_clr_polling();
2807 
2808 	/*
2809 	 * Polling state must be visible before we test NEED_RESCHED,
2810 	 * paired by resched_curr()
2811 	 */
2812 	smp_mb__after_atomic();
2813 
2814 	return unlikely(tif_need_resched());
2815 }
2816 
2817 #else
2818 static inline int tsk_is_polling(struct task_struct *p) { return 0; }
2819 static inline void __current_set_polling(void) { }
2820 static inline void __current_clr_polling(void) { }
2821 
2822 static inline bool __must_check current_set_polling_and_test(void)
2823 {
2824 	return unlikely(tif_need_resched());
2825 }
2826 static inline bool __must_check current_clr_polling_and_test(void)
2827 {
2828 	return unlikely(tif_need_resched());
2829 }
2830 #endif
2831 
2832 static inline void current_clr_polling(void)
2833 {
2834 	__current_clr_polling();
2835 
2836 	/*
2837 	 * Ensure we check TIF_NEED_RESCHED after we clear the polling bit.
2838 	 * Once the bit is cleared, we'll get IPIs with every new
2839 	 * TIF_NEED_RESCHED and the IPI handler, scheduler_ipi(), will also
2840 	 * fold.
2841 	 */
2842 	smp_mb(); /* paired with resched_curr() */
2843 
2844 	preempt_fold_need_resched();
2845 }
2846 
2847 static __always_inline bool need_resched(void)
2848 {
2849 	return unlikely(tif_need_resched());
2850 }
2851 
2852 /*
2853  * Thread group CPU time accounting.
2854  */
2855 void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
2856 void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
2857 
2858 static inline void thread_group_cputime_init(struct signal_struct *sig)
2859 {
2860 	raw_spin_lock_init(&sig->cputimer.lock);
2861 }
2862 
2863 /*
2864  * Reevaluate whether the task has signals pending delivery.
2865  * Wake the task if so.
2866  * This is required every time the blocked sigset_t changes.
2867  * callers must hold sighand->siglock.
2868  */
2869 extern void recalc_sigpending_and_wake(struct task_struct *t);
2870 extern void recalc_sigpending(void);
2871 
2872 extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
2873 
2874 static inline void signal_wake_up(struct task_struct *t, bool resume)
2875 {
2876 	signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0);
2877 }
2878 static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
2879 {
2880 	signal_wake_up_state(t, resume ? __TASK_TRACED : 0);
2881 }
2882 
2883 /*
2884  * Wrappers for p->thread_info->cpu access. No-op on UP.
2885  */
2886 #ifdef CONFIG_SMP
2887 
2888 static inline unsigned int task_cpu(const struct task_struct *p)
2889 {
2890 	return task_thread_info(p)->cpu;
2891 }
2892 
2893 static inline int task_node(const struct task_struct *p)
2894 {
2895 	return cpu_to_node(task_cpu(p));
2896 }
2897 
2898 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2899 
2900 #else
2901 
2902 static inline unsigned int task_cpu(const struct task_struct *p)
2903 {
2904 	return 0;
2905 }
2906 
2907 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2908 {
2909 }
2910 
2911 #endif /* CONFIG_SMP */
2912 
2913 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2914 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2915 
2916 #ifdef CONFIG_CGROUP_SCHED
2917 extern struct task_group root_task_group;
2918 #endif /* CONFIG_CGROUP_SCHED */
2919 
2920 extern int task_can_switch_user(struct user_struct *up,
2921 					struct task_struct *tsk);
2922 
2923 #ifdef CONFIG_TASK_XACCT
2924 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2925 {
2926 	tsk->ioac.rchar += amt;
2927 }
2928 
2929 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2930 {
2931 	tsk->ioac.wchar += amt;
2932 }
2933 
2934 static inline void inc_syscr(struct task_struct *tsk)
2935 {
2936 	tsk->ioac.syscr++;
2937 }
2938 
2939 static inline void inc_syscw(struct task_struct *tsk)
2940 {
2941 	tsk->ioac.syscw++;
2942 }
2943 #else
2944 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2945 {
2946 }
2947 
2948 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2949 {
2950 }
2951 
2952 static inline void inc_syscr(struct task_struct *tsk)
2953 {
2954 }
2955 
2956 static inline void inc_syscw(struct task_struct *tsk)
2957 {
2958 }
2959 #endif
2960 
2961 #ifndef TASK_SIZE_OF
2962 #define TASK_SIZE_OF(tsk)	TASK_SIZE
2963 #endif
2964 
2965 #ifdef CONFIG_MEMCG
2966 extern void mm_update_next_owner(struct mm_struct *mm);
2967 #else
2968 static inline void mm_update_next_owner(struct mm_struct *mm)
2969 {
2970 }
2971 #endif /* CONFIG_MEMCG */
2972 
2973 static inline unsigned long task_rlimit(const struct task_struct *tsk,
2974 		unsigned int limit)
2975 {
2976 	return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_cur);
2977 }
2978 
2979 static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
2980 		unsigned int limit)
2981 {
2982 	return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_max);
2983 }
2984 
2985 static inline unsigned long rlimit(unsigned int limit)
2986 {
2987 	return task_rlimit(current, limit);
2988 }
2989 
2990 static inline unsigned long rlimit_max(unsigned int limit)
2991 {
2992 	return task_rlimit_max(current, limit);
2993 }
2994 
2995 #endif
2996