xref: /linux/include/linux/sched.h (revision 58dae82843f508b0f1e7e8e593496ba6e2822979)
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 #include <linux/magic.h>
61 
62 #include <asm/processor.h>
63 
64 #define SCHED_ATTR_SIZE_VER0	48	/* sizeof first published struct */
65 
66 /*
67  * Extended scheduling parameters data structure.
68  *
69  * This is needed because the original struct sched_param can not be
70  * altered without introducing ABI issues with legacy applications
71  * (e.g., in sched_getparam()).
72  *
73  * However, the possibility of specifying more than just a priority for
74  * the tasks may be useful for a wide variety of application fields, e.g.,
75  * multimedia, streaming, automation and control, and many others.
76  *
77  * This variant (sched_attr) is meant at describing a so-called
78  * sporadic time-constrained task. In such model a task is specified by:
79  *  - the activation period or minimum instance inter-arrival time;
80  *  - the maximum (or average, depending on the actual scheduling
81  *    discipline) computation time of all instances, a.k.a. runtime;
82  *  - the deadline (relative to the actual activation time) of each
83  *    instance.
84  * Very briefly, a periodic (sporadic) task asks for the execution of
85  * some specific computation --which is typically called an instance--
86  * (at most) every period. Moreover, each instance typically lasts no more
87  * than the runtime and must be completed by time instant t equal to
88  * the instance activation time + the deadline.
89  *
90  * This is reflected by the actual fields of the sched_attr structure:
91  *
92  *  @size		size of the structure, for fwd/bwd compat.
93  *
94  *  @sched_policy	task's scheduling policy
95  *  @sched_flags	for customizing the scheduler behaviour
96  *  @sched_nice		task's nice value      (SCHED_NORMAL/BATCH)
97  *  @sched_priority	task's static priority (SCHED_FIFO/RR)
98  *  @sched_deadline	representative of the task's deadline
99  *  @sched_runtime	representative of the task's runtime
100  *  @sched_period	representative of the task's period
101  *
102  * Given this task model, there are a multiplicity of scheduling algorithms
103  * and policies, that can be used to ensure all the tasks will make their
104  * timing constraints.
105  *
106  * As of now, the SCHED_DEADLINE policy (sched_dl scheduling class) is the
107  * only user of this new interface. More information about the algorithm
108  * available in the scheduling class file or in Documentation/.
109  */
110 struct sched_attr {
111 	u32 size;
112 
113 	u32 sched_policy;
114 	u64 sched_flags;
115 
116 	/* SCHED_NORMAL, SCHED_BATCH */
117 	s32 sched_nice;
118 
119 	/* SCHED_FIFO, SCHED_RR */
120 	u32 sched_priority;
121 
122 	/* SCHED_DEADLINE */
123 	u64 sched_runtime;
124 	u64 sched_deadline;
125 	u64 sched_period;
126 };
127 
128 struct exec_domain;
129 struct futex_pi_state;
130 struct robust_list_head;
131 struct bio_list;
132 struct fs_struct;
133 struct perf_event_context;
134 struct blk_plug;
135 struct filename;
136 
137 #define VMACACHE_BITS 2
138 #define VMACACHE_SIZE (1U << VMACACHE_BITS)
139 #define VMACACHE_MASK (VMACACHE_SIZE - 1)
140 
141 /*
142  * These are the constant used to fake the fixed-point load-average
143  * counting. Some notes:
144  *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
145  *    a load-average precision of 10 bits integer + 11 bits fractional
146  *  - if you want to count load-averages more often, you need more
147  *    precision, or rounding will get you. With 2-second counting freq,
148  *    the EXP_n values would be 1981, 2034 and 2043 if still using only
149  *    11 bit fractions.
150  */
151 extern unsigned long avenrun[];		/* Load averages */
152 extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
153 
154 #define FSHIFT		11		/* nr of bits of precision */
155 #define FIXED_1		(1<<FSHIFT)	/* 1.0 as fixed-point */
156 #define LOAD_FREQ	(5*HZ+1)	/* 5 sec intervals */
157 #define EXP_1		1884		/* 1/exp(5sec/1min) as fixed-point */
158 #define EXP_5		2014		/* 1/exp(5sec/5min) */
159 #define EXP_15		2037		/* 1/exp(5sec/15min) */
160 
161 #define CALC_LOAD(load,exp,n) \
162 	load *= exp; \
163 	load += n*(FIXED_1-exp); \
164 	load >>= FSHIFT;
165 
166 extern unsigned long total_forks;
167 extern int nr_threads;
168 DECLARE_PER_CPU(unsigned long, process_counts);
169 extern int nr_processes(void);
170 extern unsigned long nr_running(void);
171 extern bool single_task_running(void);
172 extern unsigned long nr_iowait(void);
173 extern unsigned long nr_iowait_cpu(int cpu);
174 extern void get_iowait_load(unsigned long *nr_waiters, unsigned long *load);
175 
176 extern void calc_global_load(unsigned long ticks);
177 extern void update_cpu_load_nohz(void);
178 
179 extern unsigned long get_parent_ip(unsigned long addr);
180 
181 extern void dump_cpu_task(int cpu);
182 
183 struct seq_file;
184 struct cfs_rq;
185 struct task_group;
186 #ifdef CONFIG_SCHED_DEBUG
187 extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
188 extern void proc_sched_set_task(struct task_struct *p);
189 extern void
190 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
191 #endif
192 
193 /*
194  * Task state bitmask. NOTE! These bits are also
195  * encoded in fs/proc/array.c: get_task_state().
196  *
197  * We have two separate sets of flags: task->state
198  * is about runnability, while task->exit_state are
199  * about the task exiting. Confusing, but this way
200  * modifying one set can't modify the other one by
201  * mistake.
202  */
203 #define TASK_RUNNING		0
204 #define TASK_INTERRUPTIBLE	1
205 #define TASK_UNINTERRUPTIBLE	2
206 #define __TASK_STOPPED		4
207 #define __TASK_TRACED		8
208 /* in tsk->exit_state */
209 #define EXIT_DEAD		16
210 #define EXIT_ZOMBIE		32
211 #define EXIT_TRACE		(EXIT_ZOMBIE | EXIT_DEAD)
212 /* in tsk->state again */
213 #define TASK_DEAD		64
214 #define TASK_WAKEKILL		128
215 #define TASK_WAKING		256
216 #define TASK_PARKED		512
217 #define TASK_STATE_MAX		1024
218 
219 #define TASK_STATE_TO_CHAR_STR "RSDTtXZxKWP"
220 
221 extern char ___assert_task_state[1 - 2*!!(
222 		sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
223 
224 /* Convenience macros for the sake of set_task_state */
225 #define TASK_KILLABLE		(TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
226 #define TASK_STOPPED		(TASK_WAKEKILL | __TASK_STOPPED)
227 #define TASK_TRACED		(TASK_WAKEKILL | __TASK_TRACED)
228 
229 /* Convenience macros for the sake of wake_up */
230 #define TASK_NORMAL		(TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
231 #define TASK_ALL		(TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
232 
233 /* get_task_state() */
234 #define TASK_REPORT		(TASK_RUNNING | TASK_INTERRUPTIBLE | \
235 				 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
236 				 __TASK_TRACED | EXIT_ZOMBIE | EXIT_DEAD)
237 
238 #define task_is_traced(task)	((task->state & __TASK_TRACED) != 0)
239 #define task_is_stopped(task)	((task->state & __TASK_STOPPED) != 0)
240 #define task_is_stopped_or_traced(task)	\
241 			((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
242 #define task_contributes_to_load(task)	\
243 				((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
244 				 (task->flags & PF_FROZEN) == 0)
245 
246 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
247 
248 #define __set_task_state(tsk, state_value)			\
249 	do {							\
250 		(tsk)->task_state_change = _THIS_IP_;		\
251 		(tsk)->state = (state_value);			\
252 	} while (0)
253 #define set_task_state(tsk, state_value)			\
254 	do {							\
255 		(tsk)->task_state_change = _THIS_IP_;		\
256 		set_mb((tsk)->state, (state_value));		\
257 	} while (0)
258 
259 /*
260  * set_current_state() includes a barrier so that the write of current->state
261  * is correctly serialised wrt the caller's subsequent test of whether to
262  * actually sleep:
263  *
264  *	set_current_state(TASK_UNINTERRUPTIBLE);
265  *	if (do_i_need_to_sleep())
266  *		schedule();
267  *
268  * If the caller does not need such serialisation then use __set_current_state()
269  */
270 #define __set_current_state(state_value)			\
271 	do {							\
272 		current->task_state_change = _THIS_IP_;		\
273 		current->state = (state_value);			\
274 	} while (0)
275 #define set_current_state(state_value)				\
276 	do {							\
277 		current->task_state_change = _THIS_IP_;		\
278 		set_mb(current->state, (state_value));		\
279 	} while (0)
280 
281 #else
282 
283 #define __set_task_state(tsk, state_value)		\
284 	do { (tsk)->state = (state_value); } while (0)
285 #define set_task_state(tsk, state_value)		\
286 	set_mb((tsk)->state, (state_value))
287 
288 /*
289  * set_current_state() includes a barrier so that the write of current->state
290  * is correctly serialised wrt the caller's subsequent test of whether to
291  * actually sleep:
292  *
293  *	set_current_state(TASK_UNINTERRUPTIBLE);
294  *	if (do_i_need_to_sleep())
295  *		schedule();
296  *
297  * If the caller does not need such serialisation then use __set_current_state()
298  */
299 #define __set_current_state(state_value)		\
300 	do { current->state = (state_value); } while (0)
301 #define set_current_state(state_value)			\
302 	set_mb(current->state, (state_value))
303 
304 #endif
305 
306 /* Task command name length */
307 #define TASK_COMM_LEN 16
308 
309 #include <linux/spinlock.h>
310 
311 /*
312  * This serializes "schedule()" and also protects
313  * the run-queue from deletions/modifications (but
314  * _adding_ to the beginning of the run-queue has
315  * a separate lock).
316  */
317 extern rwlock_t tasklist_lock;
318 extern spinlock_t mmlist_lock;
319 
320 struct task_struct;
321 
322 #ifdef CONFIG_PROVE_RCU
323 extern int lockdep_tasklist_lock_is_held(void);
324 #endif /* #ifdef CONFIG_PROVE_RCU */
325 
326 extern void sched_init(void);
327 extern void sched_init_smp(void);
328 extern asmlinkage void schedule_tail(struct task_struct *prev);
329 extern void init_idle(struct task_struct *idle, int cpu);
330 extern void init_idle_bootup_task(struct task_struct *idle);
331 
332 extern int runqueue_is_locked(int cpu);
333 
334 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
335 extern void nohz_balance_enter_idle(int cpu);
336 extern void set_cpu_sd_state_idle(void);
337 extern int get_nohz_timer_target(int pinned);
338 #else
339 static inline void nohz_balance_enter_idle(int cpu) { }
340 static inline void set_cpu_sd_state_idle(void) { }
341 static inline int get_nohz_timer_target(int pinned)
342 {
343 	return smp_processor_id();
344 }
345 #endif
346 
347 /*
348  * Only dump TASK_* tasks. (0 for all tasks)
349  */
350 extern void show_state_filter(unsigned long state_filter);
351 
352 static inline void show_state(void)
353 {
354 	show_state_filter(0);
355 }
356 
357 extern void show_regs(struct pt_regs *);
358 
359 /*
360  * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
361  * task), SP is the stack pointer of the first frame that should be shown in the back
362  * trace (or NULL if the entire call-chain of the task should be shown).
363  */
364 extern void show_stack(struct task_struct *task, unsigned long *sp);
365 
366 extern void cpu_init (void);
367 extern void trap_init(void);
368 extern void update_process_times(int user);
369 extern void scheduler_tick(void);
370 
371 extern void sched_show_task(struct task_struct *p);
372 
373 #ifdef CONFIG_LOCKUP_DETECTOR
374 extern void touch_softlockup_watchdog(void);
375 extern void touch_softlockup_watchdog_sync(void);
376 extern void touch_all_softlockup_watchdogs(void);
377 extern int proc_dowatchdog_thresh(struct ctl_table *table, int write,
378 				  void __user *buffer,
379 				  size_t *lenp, loff_t *ppos);
380 extern unsigned int  softlockup_panic;
381 void lockup_detector_init(void);
382 #else
383 static inline void touch_softlockup_watchdog(void)
384 {
385 }
386 static inline void touch_softlockup_watchdog_sync(void)
387 {
388 }
389 static inline void touch_all_softlockup_watchdogs(void)
390 {
391 }
392 static inline void lockup_detector_init(void)
393 {
394 }
395 #endif
396 
397 #ifdef CONFIG_DETECT_HUNG_TASK
398 void reset_hung_task_detector(void);
399 #else
400 static inline void reset_hung_task_detector(void)
401 {
402 }
403 #endif
404 
405 /* Attach to any functions which should be ignored in wchan output. */
406 #define __sched		__attribute__((__section__(".sched.text")))
407 
408 /* Linker adds these: start and end of __sched functions */
409 extern char __sched_text_start[], __sched_text_end[];
410 
411 /* Is this address in the __sched functions? */
412 extern int in_sched_functions(unsigned long addr);
413 
414 #define	MAX_SCHEDULE_TIMEOUT	LONG_MAX
415 extern signed long schedule_timeout(signed long timeout);
416 extern signed long schedule_timeout_interruptible(signed long timeout);
417 extern signed long schedule_timeout_killable(signed long timeout);
418 extern signed long schedule_timeout_uninterruptible(signed long timeout);
419 asmlinkage void schedule(void);
420 extern void schedule_preempt_disabled(void);
421 
422 extern long io_schedule_timeout(long timeout);
423 
424 static inline void io_schedule(void)
425 {
426 	io_schedule_timeout(MAX_SCHEDULE_TIMEOUT);
427 }
428 
429 struct nsproxy;
430 struct user_namespace;
431 
432 #ifdef CONFIG_MMU
433 extern void arch_pick_mmap_layout(struct mm_struct *mm);
434 extern unsigned long
435 arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
436 		       unsigned long, unsigned long);
437 extern unsigned long
438 arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
439 			  unsigned long len, unsigned long pgoff,
440 			  unsigned long flags);
441 #else
442 static inline void arch_pick_mmap_layout(struct mm_struct *mm) {}
443 #endif
444 
445 #define SUID_DUMP_DISABLE	0	/* No setuid dumping */
446 #define SUID_DUMP_USER		1	/* Dump as user of process */
447 #define SUID_DUMP_ROOT		2	/* Dump as root */
448 
449 /* mm flags */
450 
451 /* for SUID_DUMP_* above */
452 #define MMF_DUMPABLE_BITS 2
453 #define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
454 
455 extern void set_dumpable(struct mm_struct *mm, int value);
456 /*
457  * This returns the actual value of the suid_dumpable flag. For things
458  * that are using this for checking for privilege transitions, it must
459  * test against SUID_DUMP_USER rather than treating it as a boolean
460  * value.
461  */
462 static inline int __get_dumpable(unsigned long mm_flags)
463 {
464 	return mm_flags & MMF_DUMPABLE_MASK;
465 }
466 
467 static inline int get_dumpable(struct mm_struct *mm)
468 {
469 	return __get_dumpable(mm->flags);
470 }
471 
472 /* coredump filter bits */
473 #define MMF_DUMP_ANON_PRIVATE	2
474 #define MMF_DUMP_ANON_SHARED	3
475 #define MMF_DUMP_MAPPED_PRIVATE	4
476 #define MMF_DUMP_MAPPED_SHARED	5
477 #define MMF_DUMP_ELF_HEADERS	6
478 #define MMF_DUMP_HUGETLB_PRIVATE 7
479 #define MMF_DUMP_HUGETLB_SHARED  8
480 
481 #define MMF_DUMP_FILTER_SHIFT	MMF_DUMPABLE_BITS
482 #define MMF_DUMP_FILTER_BITS	7
483 #define MMF_DUMP_FILTER_MASK \
484 	(((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
485 #define MMF_DUMP_FILTER_DEFAULT \
486 	((1 << MMF_DUMP_ANON_PRIVATE) |	(1 << MMF_DUMP_ANON_SHARED) |\
487 	 (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
488 
489 #ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
490 # define MMF_DUMP_MASK_DEFAULT_ELF	(1 << MMF_DUMP_ELF_HEADERS)
491 #else
492 # define MMF_DUMP_MASK_DEFAULT_ELF	0
493 #endif
494 					/* leave room for more dump flags */
495 #define MMF_VM_MERGEABLE	16	/* KSM may merge identical pages */
496 #define MMF_VM_HUGEPAGE		17	/* set when VM_HUGEPAGE is set on vma */
497 #define MMF_EXE_FILE_CHANGED	18	/* see prctl_set_mm_exe_file() */
498 
499 #define MMF_HAS_UPROBES		19	/* has uprobes */
500 #define MMF_RECALC_UPROBES	20	/* MMF_HAS_UPROBES can be wrong */
501 
502 #define MMF_INIT_MASK		(MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
503 
504 struct sighand_struct {
505 	atomic_t		count;
506 	struct k_sigaction	action[_NSIG];
507 	spinlock_t		siglock;
508 	wait_queue_head_t	signalfd_wqh;
509 };
510 
511 struct pacct_struct {
512 	int			ac_flag;
513 	long			ac_exitcode;
514 	unsigned long		ac_mem;
515 	cputime_t		ac_utime, ac_stime;
516 	unsigned long		ac_minflt, ac_majflt;
517 };
518 
519 struct cpu_itimer {
520 	cputime_t expires;
521 	cputime_t incr;
522 	u32 error;
523 	u32 incr_error;
524 };
525 
526 /**
527  * struct cputime - snaphsot of system and user cputime
528  * @utime: time spent in user mode
529  * @stime: time spent in system mode
530  *
531  * Gathers a generic snapshot of user and system time.
532  */
533 struct cputime {
534 	cputime_t utime;
535 	cputime_t stime;
536 };
537 
538 /**
539  * struct task_cputime - collected CPU time counts
540  * @utime:		time spent in user mode, in &cputime_t units
541  * @stime:		time spent in kernel mode, in &cputime_t units
542  * @sum_exec_runtime:	total time spent on the CPU, in nanoseconds
543  *
544  * This is an extension of struct cputime that includes the total runtime
545  * spent by the task from the scheduler point of view.
546  *
547  * As a result, this structure groups together three kinds of CPU time
548  * that are tracked for threads and thread groups.  Most things considering
549  * CPU time want to group these counts together and treat all three
550  * of them in parallel.
551  */
552 struct task_cputime {
553 	cputime_t utime;
554 	cputime_t stime;
555 	unsigned long long sum_exec_runtime;
556 };
557 /* Alternate field names when used to cache expirations. */
558 #define prof_exp	stime
559 #define virt_exp	utime
560 #define sched_exp	sum_exec_runtime
561 
562 #define INIT_CPUTIME	\
563 	(struct task_cputime) {					\
564 		.utime = 0,					\
565 		.stime = 0,					\
566 		.sum_exec_runtime = 0,				\
567 	}
568 
569 #ifdef CONFIG_PREEMPT_COUNT
570 #define PREEMPT_DISABLED	(1 + PREEMPT_ENABLED)
571 #else
572 #define PREEMPT_DISABLED	PREEMPT_ENABLED
573 #endif
574 
575 /*
576  * Disable preemption until the scheduler is running.
577  * Reset by start_kernel()->sched_init()->init_idle().
578  *
579  * We include PREEMPT_ACTIVE to avoid cond_resched() from working
580  * before the scheduler is active -- see should_resched().
581  */
582 #define INIT_PREEMPT_COUNT	(PREEMPT_DISABLED + PREEMPT_ACTIVE)
583 
584 /**
585  * struct thread_group_cputimer - thread group interval timer counts
586  * @cputime:		thread group interval timers.
587  * @running:		non-zero when there are timers running and
588  * 			@cputime receives updates.
589  * @lock:		lock for fields in this struct.
590  *
591  * This structure contains the version of task_cputime, above, that is
592  * used for thread group CPU timer calculations.
593  */
594 struct thread_group_cputimer {
595 	struct task_cputime cputime;
596 	int running;
597 	raw_spinlock_t lock;
598 };
599 
600 #include <linux/rwsem.h>
601 struct autogroup;
602 
603 /*
604  * NOTE! "signal_struct" does not have its own
605  * locking, because a shared signal_struct always
606  * implies a shared sighand_struct, so locking
607  * sighand_struct is always a proper superset of
608  * the locking of signal_struct.
609  */
610 struct signal_struct {
611 	atomic_t		sigcnt;
612 	atomic_t		live;
613 	int			nr_threads;
614 	struct list_head	thread_head;
615 
616 	wait_queue_head_t	wait_chldexit;	/* for wait4() */
617 
618 	/* current thread group signal load-balancing target: */
619 	struct task_struct	*curr_target;
620 
621 	/* shared signal handling: */
622 	struct sigpending	shared_pending;
623 
624 	/* thread group exit support */
625 	int			group_exit_code;
626 	/* overloaded:
627 	 * - notify group_exit_task when ->count is equal to notify_count
628 	 * - everyone except group_exit_task is stopped during signal delivery
629 	 *   of fatal signals, group_exit_task processes the signal.
630 	 */
631 	int			notify_count;
632 	struct task_struct	*group_exit_task;
633 
634 	/* thread group stop support, overloads group_exit_code too */
635 	int			group_stop_count;
636 	unsigned int		flags; /* see SIGNAL_* flags below */
637 
638 	/*
639 	 * PR_SET_CHILD_SUBREAPER marks a process, like a service
640 	 * manager, to re-parent orphan (double-forking) child processes
641 	 * to this process instead of 'init'. The service manager is
642 	 * able to receive SIGCHLD signals and is able to investigate
643 	 * the process until it calls wait(). All children of this
644 	 * process will inherit a flag if they should look for a
645 	 * child_subreaper process at exit.
646 	 */
647 	unsigned int		is_child_subreaper:1;
648 	unsigned int		has_child_subreaper:1;
649 
650 	/* POSIX.1b Interval Timers */
651 	int			posix_timer_id;
652 	struct list_head	posix_timers;
653 
654 	/* ITIMER_REAL timer for the process */
655 	struct hrtimer real_timer;
656 	struct pid *leader_pid;
657 	ktime_t it_real_incr;
658 
659 	/*
660 	 * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
661 	 * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
662 	 * values are defined to 0 and 1 respectively
663 	 */
664 	struct cpu_itimer it[2];
665 
666 	/*
667 	 * Thread group totals for process CPU timers.
668 	 * See thread_group_cputimer(), et al, for details.
669 	 */
670 	struct thread_group_cputimer cputimer;
671 
672 	/* Earliest-expiration cache. */
673 	struct task_cputime cputime_expires;
674 
675 	struct list_head cpu_timers[3];
676 
677 	struct pid *tty_old_pgrp;
678 
679 	/* boolean value for session group leader */
680 	int leader;
681 
682 	struct tty_struct *tty; /* NULL if no tty */
683 
684 #ifdef CONFIG_SCHED_AUTOGROUP
685 	struct autogroup *autogroup;
686 #endif
687 	/*
688 	 * Cumulative resource counters for dead threads in the group,
689 	 * and for reaped dead child processes forked by this group.
690 	 * Live threads maintain their own counters and add to these
691 	 * in __exit_signal, except for the group leader.
692 	 */
693 	seqlock_t stats_lock;
694 	cputime_t utime, stime, cutime, cstime;
695 	cputime_t gtime;
696 	cputime_t cgtime;
697 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
698 	struct cputime prev_cputime;
699 #endif
700 	unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
701 	unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
702 	unsigned long inblock, oublock, cinblock, coublock;
703 	unsigned long maxrss, cmaxrss;
704 	struct task_io_accounting ioac;
705 
706 	/*
707 	 * Cumulative ns of schedule CPU time fo dead threads in the
708 	 * group, not including a zombie group leader, (This only differs
709 	 * from jiffies_to_ns(utime + stime) if sched_clock uses something
710 	 * other than jiffies.)
711 	 */
712 	unsigned long long sum_sched_runtime;
713 
714 	/*
715 	 * We don't bother to synchronize most readers of this at all,
716 	 * because there is no reader checking a limit that actually needs
717 	 * to get both rlim_cur and rlim_max atomically, and either one
718 	 * alone is a single word that can safely be read normally.
719 	 * getrlimit/setrlimit use task_lock(current->group_leader) to
720 	 * protect this instead of the siglock, because they really
721 	 * have no need to disable irqs.
722 	 */
723 	struct rlimit rlim[RLIM_NLIMITS];
724 
725 #ifdef CONFIG_BSD_PROCESS_ACCT
726 	struct pacct_struct pacct;	/* per-process accounting information */
727 #endif
728 #ifdef CONFIG_TASKSTATS
729 	struct taskstats *stats;
730 #endif
731 #ifdef CONFIG_AUDIT
732 	unsigned audit_tty;
733 	unsigned audit_tty_log_passwd;
734 	struct tty_audit_buf *tty_audit_buf;
735 #endif
736 #ifdef CONFIG_CGROUPS
737 	/*
738 	 * group_rwsem prevents new tasks from entering the threadgroup and
739 	 * member tasks from exiting,a more specifically, setting of
740 	 * PF_EXITING.  fork and exit paths are protected with this rwsem
741 	 * using threadgroup_change_begin/end().  Users which require
742 	 * threadgroup to remain stable should use threadgroup_[un]lock()
743 	 * which also takes care of exec path.  Currently, cgroup is the
744 	 * only user.
745 	 */
746 	struct rw_semaphore group_rwsem;
747 #endif
748 
749 	oom_flags_t oom_flags;
750 	short oom_score_adj;		/* OOM kill score adjustment */
751 	short oom_score_adj_min;	/* OOM kill score adjustment min value.
752 					 * Only settable by CAP_SYS_RESOURCE. */
753 
754 	struct mutex cred_guard_mutex;	/* guard against foreign influences on
755 					 * credential calculations
756 					 * (notably. ptrace) */
757 };
758 
759 /*
760  * Bits in flags field of signal_struct.
761  */
762 #define SIGNAL_STOP_STOPPED	0x00000001 /* job control stop in effect */
763 #define SIGNAL_STOP_CONTINUED	0x00000002 /* SIGCONT since WCONTINUED reap */
764 #define SIGNAL_GROUP_EXIT	0x00000004 /* group exit in progress */
765 #define SIGNAL_GROUP_COREDUMP	0x00000008 /* coredump in progress */
766 /*
767  * Pending notifications to parent.
768  */
769 #define SIGNAL_CLD_STOPPED	0x00000010
770 #define SIGNAL_CLD_CONTINUED	0x00000020
771 #define SIGNAL_CLD_MASK		(SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
772 
773 #define SIGNAL_UNKILLABLE	0x00000040 /* for init: ignore fatal signals */
774 
775 /* If true, all threads except ->group_exit_task have pending SIGKILL */
776 static inline int signal_group_exit(const struct signal_struct *sig)
777 {
778 	return	(sig->flags & SIGNAL_GROUP_EXIT) ||
779 		(sig->group_exit_task != NULL);
780 }
781 
782 /*
783  * Some day this will be a full-fledged user tracking system..
784  */
785 struct user_struct {
786 	atomic_t __count;	/* reference count */
787 	atomic_t processes;	/* How many processes does this user have? */
788 	atomic_t sigpending;	/* How many pending signals does this user have? */
789 #ifdef CONFIG_INOTIFY_USER
790 	atomic_t inotify_watches; /* How many inotify watches does this user have? */
791 	atomic_t inotify_devs;	/* How many inotify devs does this user have opened? */
792 #endif
793 #ifdef CONFIG_FANOTIFY
794 	atomic_t fanotify_listeners;
795 #endif
796 #ifdef CONFIG_EPOLL
797 	atomic_long_t epoll_watches; /* The number of file descriptors currently watched */
798 #endif
799 #ifdef CONFIG_POSIX_MQUEUE
800 	/* protected by mq_lock	*/
801 	unsigned long mq_bytes;	/* How many bytes can be allocated to mqueue? */
802 #endif
803 	unsigned long locked_shm; /* How many pages of mlocked shm ? */
804 
805 #ifdef CONFIG_KEYS
806 	struct key *uid_keyring;	/* UID specific keyring */
807 	struct key *session_keyring;	/* UID's default session keyring */
808 #endif
809 
810 	/* Hash table maintenance information */
811 	struct hlist_node uidhash_node;
812 	kuid_t uid;
813 
814 #ifdef CONFIG_PERF_EVENTS
815 	atomic_long_t locked_vm;
816 #endif
817 };
818 
819 extern int uids_sysfs_init(void);
820 
821 extern struct user_struct *find_user(kuid_t);
822 
823 extern struct user_struct root_user;
824 #define INIT_USER (&root_user)
825 
826 
827 struct backing_dev_info;
828 struct reclaim_state;
829 
830 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
831 struct sched_info {
832 	/* cumulative counters */
833 	unsigned long pcount;	      /* # of times run on this cpu */
834 	unsigned long long run_delay; /* time spent waiting on a runqueue */
835 
836 	/* timestamps */
837 	unsigned long long last_arrival,/* when we last ran on a cpu */
838 			   last_queued;	/* when we were last queued to run */
839 };
840 #endif /* defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) */
841 
842 #ifdef CONFIG_TASK_DELAY_ACCT
843 struct task_delay_info {
844 	spinlock_t	lock;
845 	unsigned int	flags;	/* Private per-task flags */
846 
847 	/* For each stat XXX, add following, aligned appropriately
848 	 *
849 	 * struct timespec XXX_start, XXX_end;
850 	 * u64 XXX_delay;
851 	 * u32 XXX_count;
852 	 *
853 	 * Atomicity of updates to XXX_delay, XXX_count protected by
854 	 * single lock above (split into XXX_lock if contention is an issue).
855 	 */
856 
857 	/*
858 	 * XXX_count is incremented on every XXX operation, the delay
859 	 * associated with the operation is added to XXX_delay.
860 	 * XXX_delay contains the accumulated delay time in nanoseconds.
861 	 */
862 	u64 blkio_start;	/* Shared by blkio, swapin */
863 	u64 blkio_delay;	/* wait for sync block io completion */
864 	u64 swapin_delay;	/* wait for swapin block io completion */
865 	u32 blkio_count;	/* total count of the number of sync block */
866 				/* io operations performed */
867 	u32 swapin_count;	/* total count of the number of swapin block */
868 				/* io operations performed */
869 
870 	u64 freepages_start;
871 	u64 freepages_delay;	/* wait for memory reclaim */
872 	u32 freepages_count;	/* total count of memory reclaim */
873 };
874 #endif	/* CONFIG_TASK_DELAY_ACCT */
875 
876 static inline int sched_info_on(void)
877 {
878 #ifdef CONFIG_SCHEDSTATS
879 	return 1;
880 #elif defined(CONFIG_TASK_DELAY_ACCT)
881 	extern int delayacct_on;
882 	return delayacct_on;
883 #else
884 	return 0;
885 #endif
886 }
887 
888 enum cpu_idle_type {
889 	CPU_IDLE,
890 	CPU_NOT_IDLE,
891 	CPU_NEWLY_IDLE,
892 	CPU_MAX_IDLE_TYPES
893 };
894 
895 /*
896  * Increase resolution of cpu_capacity calculations
897  */
898 #define SCHED_CAPACITY_SHIFT	10
899 #define SCHED_CAPACITY_SCALE	(1L << SCHED_CAPACITY_SHIFT)
900 
901 /*
902  * sched-domains (multiprocessor balancing) declarations:
903  */
904 #ifdef CONFIG_SMP
905 #define SD_LOAD_BALANCE		0x0001	/* Do load balancing on this domain. */
906 #define SD_BALANCE_NEWIDLE	0x0002	/* Balance when about to become idle */
907 #define SD_BALANCE_EXEC		0x0004	/* Balance on exec */
908 #define SD_BALANCE_FORK		0x0008	/* Balance on fork, clone */
909 #define SD_BALANCE_WAKE		0x0010  /* Balance on wakeup */
910 #define SD_WAKE_AFFINE		0x0020	/* Wake task to waking CPU */
911 #define SD_SHARE_CPUCAPACITY	0x0080	/* Domain members share cpu power */
912 #define SD_SHARE_POWERDOMAIN	0x0100	/* Domain members share power domain */
913 #define SD_SHARE_PKG_RESOURCES	0x0200	/* Domain members share cpu pkg resources */
914 #define SD_SERIALIZE		0x0400	/* Only a single load balancing instance */
915 #define SD_ASYM_PACKING		0x0800  /* Place busy groups earlier in the domain */
916 #define SD_PREFER_SIBLING	0x1000	/* Prefer to place tasks in a sibling domain */
917 #define SD_OVERLAP		0x2000	/* sched_domains of this level overlap */
918 #define SD_NUMA			0x4000	/* cross-node balancing */
919 
920 #ifdef CONFIG_SCHED_SMT
921 static inline int cpu_smt_flags(void)
922 {
923 	return SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
924 }
925 #endif
926 
927 #ifdef CONFIG_SCHED_MC
928 static inline int cpu_core_flags(void)
929 {
930 	return SD_SHARE_PKG_RESOURCES;
931 }
932 #endif
933 
934 #ifdef CONFIG_NUMA
935 static inline int cpu_numa_flags(void)
936 {
937 	return SD_NUMA;
938 }
939 #endif
940 
941 struct sched_domain_attr {
942 	int relax_domain_level;
943 };
944 
945 #define SD_ATTR_INIT	(struct sched_domain_attr) {	\
946 	.relax_domain_level = -1,			\
947 }
948 
949 extern int sched_domain_level_max;
950 
951 struct sched_group;
952 
953 struct sched_domain {
954 	/* These fields must be setup */
955 	struct sched_domain *parent;	/* top domain must be null terminated */
956 	struct sched_domain *child;	/* bottom domain must be null terminated */
957 	struct sched_group *groups;	/* the balancing groups of the domain */
958 	unsigned long min_interval;	/* Minimum balance interval ms */
959 	unsigned long max_interval;	/* Maximum balance interval ms */
960 	unsigned int busy_factor;	/* less balancing by factor if busy */
961 	unsigned int imbalance_pct;	/* No balance until over watermark */
962 	unsigned int cache_nice_tries;	/* Leave cache hot tasks for # tries */
963 	unsigned int busy_idx;
964 	unsigned int idle_idx;
965 	unsigned int newidle_idx;
966 	unsigned int wake_idx;
967 	unsigned int forkexec_idx;
968 	unsigned int smt_gain;
969 
970 	int nohz_idle;			/* NOHZ IDLE status */
971 	int flags;			/* See SD_* */
972 	int level;
973 
974 	/* Runtime fields. */
975 	unsigned long last_balance;	/* init to jiffies. units in jiffies */
976 	unsigned int balance_interval;	/* initialise to 1. units in ms. */
977 	unsigned int nr_balance_failed; /* initialise to 0 */
978 
979 	/* idle_balance() stats */
980 	u64 max_newidle_lb_cost;
981 	unsigned long next_decay_max_lb_cost;
982 
983 #ifdef CONFIG_SCHEDSTATS
984 	/* load_balance() stats */
985 	unsigned int lb_count[CPU_MAX_IDLE_TYPES];
986 	unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
987 	unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
988 	unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
989 	unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
990 	unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
991 	unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
992 	unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
993 
994 	/* Active load balancing */
995 	unsigned int alb_count;
996 	unsigned int alb_failed;
997 	unsigned int alb_pushed;
998 
999 	/* SD_BALANCE_EXEC stats */
1000 	unsigned int sbe_count;
1001 	unsigned int sbe_balanced;
1002 	unsigned int sbe_pushed;
1003 
1004 	/* SD_BALANCE_FORK stats */
1005 	unsigned int sbf_count;
1006 	unsigned int sbf_balanced;
1007 	unsigned int sbf_pushed;
1008 
1009 	/* try_to_wake_up() stats */
1010 	unsigned int ttwu_wake_remote;
1011 	unsigned int ttwu_move_affine;
1012 	unsigned int ttwu_move_balance;
1013 #endif
1014 #ifdef CONFIG_SCHED_DEBUG
1015 	char *name;
1016 #endif
1017 	union {
1018 		void *private;		/* used during construction */
1019 		struct rcu_head rcu;	/* used during destruction */
1020 	};
1021 
1022 	unsigned int span_weight;
1023 	/*
1024 	 * Span of all CPUs in this domain.
1025 	 *
1026 	 * NOTE: this field is variable length. (Allocated dynamically
1027 	 * by attaching extra space to the end of the structure,
1028 	 * depending on how many CPUs the kernel has booted up with)
1029 	 */
1030 	unsigned long span[0];
1031 };
1032 
1033 static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
1034 {
1035 	return to_cpumask(sd->span);
1036 }
1037 
1038 extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1039 				    struct sched_domain_attr *dattr_new);
1040 
1041 /* Allocate an array of sched domains, for partition_sched_domains(). */
1042 cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
1043 void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
1044 
1045 bool cpus_share_cache(int this_cpu, int that_cpu);
1046 
1047 typedef const struct cpumask *(*sched_domain_mask_f)(int cpu);
1048 typedef int (*sched_domain_flags_f)(void);
1049 
1050 #define SDTL_OVERLAP	0x01
1051 
1052 struct sd_data {
1053 	struct sched_domain **__percpu sd;
1054 	struct sched_group **__percpu sg;
1055 	struct sched_group_capacity **__percpu sgc;
1056 };
1057 
1058 struct sched_domain_topology_level {
1059 	sched_domain_mask_f mask;
1060 	sched_domain_flags_f sd_flags;
1061 	int		    flags;
1062 	int		    numa_level;
1063 	struct sd_data      data;
1064 #ifdef CONFIG_SCHED_DEBUG
1065 	char                *name;
1066 #endif
1067 };
1068 
1069 extern struct sched_domain_topology_level *sched_domain_topology;
1070 
1071 extern void set_sched_topology(struct sched_domain_topology_level *tl);
1072 extern void wake_up_if_idle(int cpu);
1073 
1074 #ifdef CONFIG_SCHED_DEBUG
1075 # define SD_INIT_NAME(type)		.name = #type
1076 #else
1077 # define SD_INIT_NAME(type)
1078 #endif
1079 
1080 #else /* CONFIG_SMP */
1081 
1082 struct sched_domain_attr;
1083 
1084 static inline void
1085 partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1086 			struct sched_domain_attr *dattr_new)
1087 {
1088 }
1089 
1090 static inline bool cpus_share_cache(int this_cpu, int that_cpu)
1091 {
1092 	return true;
1093 }
1094 
1095 #endif	/* !CONFIG_SMP */
1096 
1097 
1098 struct io_context;			/* See blkdev.h */
1099 
1100 
1101 #ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
1102 extern void prefetch_stack(struct task_struct *t);
1103 #else
1104 static inline void prefetch_stack(struct task_struct *t) { }
1105 #endif
1106 
1107 struct audit_context;		/* See audit.c */
1108 struct mempolicy;
1109 struct pipe_inode_info;
1110 struct uts_namespace;
1111 
1112 struct load_weight {
1113 	unsigned long weight;
1114 	u32 inv_weight;
1115 };
1116 
1117 struct sched_avg {
1118 	/*
1119 	 * These sums represent an infinite geometric series and so are bound
1120 	 * above by 1024/(1-y).  Thus we only need a u32 to store them for all
1121 	 * choices of y < 1-2^(-32)*1024.
1122 	 */
1123 	u32 runnable_avg_sum, runnable_avg_period;
1124 	u64 last_runnable_update;
1125 	s64 decay_count;
1126 	unsigned long load_avg_contrib;
1127 };
1128 
1129 #ifdef CONFIG_SCHEDSTATS
1130 struct sched_statistics {
1131 	u64			wait_start;
1132 	u64			wait_max;
1133 	u64			wait_count;
1134 	u64			wait_sum;
1135 	u64			iowait_count;
1136 	u64			iowait_sum;
1137 
1138 	u64			sleep_start;
1139 	u64			sleep_max;
1140 	s64			sum_sleep_runtime;
1141 
1142 	u64			block_start;
1143 	u64			block_max;
1144 	u64			exec_max;
1145 	u64			slice_max;
1146 
1147 	u64			nr_migrations_cold;
1148 	u64			nr_failed_migrations_affine;
1149 	u64			nr_failed_migrations_running;
1150 	u64			nr_failed_migrations_hot;
1151 	u64			nr_forced_migrations;
1152 
1153 	u64			nr_wakeups;
1154 	u64			nr_wakeups_sync;
1155 	u64			nr_wakeups_migrate;
1156 	u64			nr_wakeups_local;
1157 	u64			nr_wakeups_remote;
1158 	u64			nr_wakeups_affine;
1159 	u64			nr_wakeups_affine_attempts;
1160 	u64			nr_wakeups_passive;
1161 	u64			nr_wakeups_idle;
1162 };
1163 #endif
1164 
1165 struct sched_entity {
1166 	struct load_weight	load;		/* for load-balancing */
1167 	struct rb_node		run_node;
1168 	struct list_head	group_node;
1169 	unsigned int		on_rq;
1170 
1171 	u64			exec_start;
1172 	u64			sum_exec_runtime;
1173 	u64			vruntime;
1174 	u64			prev_sum_exec_runtime;
1175 
1176 	u64			nr_migrations;
1177 
1178 #ifdef CONFIG_SCHEDSTATS
1179 	struct sched_statistics statistics;
1180 #endif
1181 
1182 #ifdef CONFIG_FAIR_GROUP_SCHED
1183 	int			depth;
1184 	struct sched_entity	*parent;
1185 	/* rq on which this entity is (to be) queued: */
1186 	struct cfs_rq		*cfs_rq;
1187 	/* rq "owned" by this entity/group: */
1188 	struct cfs_rq		*my_q;
1189 #endif
1190 
1191 #ifdef CONFIG_SMP
1192 	/* Per-entity load-tracking */
1193 	struct sched_avg	avg;
1194 #endif
1195 };
1196 
1197 struct sched_rt_entity {
1198 	struct list_head run_list;
1199 	unsigned long timeout;
1200 	unsigned long watchdog_stamp;
1201 	unsigned int time_slice;
1202 
1203 	struct sched_rt_entity *back;
1204 #ifdef CONFIG_RT_GROUP_SCHED
1205 	struct sched_rt_entity	*parent;
1206 	/* rq on which this entity is (to be) queued: */
1207 	struct rt_rq		*rt_rq;
1208 	/* rq "owned" by this entity/group: */
1209 	struct rt_rq		*my_q;
1210 #endif
1211 };
1212 
1213 struct sched_dl_entity {
1214 	struct rb_node	rb_node;
1215 
1216 	/*
1217 	 * Original scheduling parameters. Copied here from sched_attr
1218 	 * during sched_setattr(), they will remain the same until
1219 	 * the next sched_setattr().
1220 	 */
1221 	u64 dl_runtime;		/* maximum runtime for each instance	*/
1222 	u64 dl_deadline;	/* relative deadline of each instance	*/
1223 	u64 dl_period;		/* separation of two instances (period) */
1224 	u64 dl_bw;		/* dl_runtime / dl_deadline		*/
1225 
1226 	/*
1227 	 * Actual scheduling parameters. Initialized with the values above,
1228 	 * they are continously updated during task execution. Note that
1229 	 * the remaining runtime could be < 0 in case we are in overrun.
1230 	 */
1231 	s64 runtime;		/* remaining runtime for this instance	*/
1232 	u64 deadline;		/* absolute deadline for this instance	*/
1233 	unsigned int flags;	/* specifying the scheduler behaviour	*/
1234 
1235 	/*
1236 	 * Some bool flags:
1237 	 *
1238 	 * @dl_throttled tells if we exhausted the runtime. If so, the
1239 	 * task has to wait for a replenishment to be performed at the
1240 	 * next firing of dl_timer.
1241 	 *
1242 	 * @dl_new tells if a new instance arrived. If so we must
1243 	 * start executing it with full runtime and reset its absolute
1244 	 * deadline;
1245 	 *
1246 	 * @dl_boosted tells if we are boosted due to DI. If so we are
1247 	 * outside bandwidth enforcement mechanism (but only until we
1248 	 * exit the critical section);
1249 	 *
1250 	 * @dl_yielded tells if task gave up the cpu before consuming
1251 	 * all its available runtime during the last job.
1252 	 */
1253 	int dl_throttled, dl_new, dl_boosted, dl_yielded;
1254 
1255 	/*
1256 	 * Bandwidth enforcement timer. Each -deadline task has its
1257 	 * own bandwidth to be enforced, thus we need one timer per task.
1258 	 */
1259 	struct hrtimer dl_timer;
1260 };
1261 
1262 union rcu_special {
1263 	struct {
1264 		bool blocked;
1265 		bool need_qs;
1266 	} b;
1267 	short s;
1268 };
1269 struct rcu_node;
1270 
1271 enum perf_event_task_context {
1272 	perf_invalid_context = -1,
1273 	perf_hw_context = 0,
1274 	perf_sw_context,
1275 	perf_nr_task_contexts,
1276 };
1277 
1278 struct task_struct {
1279 	volatile long state;	/* -1 unrunnable, 0 runnable, >0 stopped */
1280 	void *stack;
1281 	atomic_t usage;
1282 	unsigned int flags;	/* per process flags, defined below */
1283 	unsigned int ptrace;
1284 
1285 #ifdef CONFIG_SMP
1286 	struct llist_node wake_entry;
1287 	int on_cpu;
1288 	struct task_struct *last_wakee;
1289 	unsigned long wakee_flips;
1290 	unsigned long wakee_flip_decay_ts;
1291 
1292 	int wake_cpu;
1293 #endif
1294 	int on_rq;
1295 
1296 	int prio, static_prio, normal_prio;
1297 	unsigned int rt_priority;
1298 	const struct sched_class *sched_class;
1299 	struct sched_entity se;
1300 	struct sched_rt_entity rt;
1301 #ifdef CONFIG_CGROUP_SCHED
1302 	struct task_group *sched_task_group;
1303 #endif
1304 	struct sched_dl_entity dl;
1305 
1306 #ifdef CONFIG_PREEMPT_NOTIFIERS
1307 	/* list of struct preempt_notifier: */
1308 	struct hlist_head preempt_notifiers;
1309 #endif
1310 
1311 #ifdef CONFIG_BLK_DEV_IO_TRACE
1312 	unsigned int btrace_seq;
1313 #endif
1314 
1315 	unsigned int policy;
1316 	int nr_cpus_allowed;
1317 	cpumask_t cpus_allowed;
1318 
1319 #ifdef CONFIG_PREEMPT_RCU
1320 	int rcu_read_lock_nesting;
1321 	union rcu_special rcu_read_unlock_special;
1322 	struct list_head rcu_node_entry;
1323 #endif /* #ifdef CONFIG_PREEMPT_RCU */
1324 #ifdef CONFIG_PREEMPT_RCU
1325 	struct rcu_node *rcu_blocked_node;
1326 #endif /* #ifdef CONFIG_PREEMPT_RCU */
1327 #ifdef CONFIG_TASKS_RCU
1328 	unsigned long rcu_tasks_nvcsw;
1329 	bool rcu_tasks_holdout;
1330 	struct list_head rcu_tasks_holdout_list;
1331 	int rcu_tasks_idle_cpu;
1332 #endif /* #ifdef CONFIG_TASKS_RCU */
1333 
1334 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
1335 	struct sched_info sched_info;
1336 #endif
1337 
1338 	struct list_head tasks;
1339 #ifdef CONFIG_SMP
1340 	struct plist_node pushable_tasks;
1341 	struct rb_node pushable_dl_tasks;
1342 #endif
1343 
1344 	struct mm_struct *mm, *active_mm;
1345 #ifdef CONFIG_COMPAT_BRK
1346 	unsigned brk_randomized:1;
1347 #endif
1348 	/* per-thread vma caching */
1349 	u32 vmacache_seqnum;
1350 	struct vm_area_struct *vmacache[VMACACHE_SIZE];
1351 #if defined(SPLIT_RSS_COUNTING)
1352 	struct task_rss_stat	rss_stat;
1353 #endif
1354 /* task state */
1355 	int exit_state;
1356 	int exit_code, exit_signal;
1357 	int pdeath_signal;  /*  The signal sent when the parent dies  */
1358 	unsigned int jobctl;	/* JOBCTL_*, siglock protected */
1359 
1360 	/* Used for emulating ABI behavior of previous Linux versions */
1361 	unsigned int personality;
1362 
1363 	unsigned in_execve:1;	/* Tell the LSMs that the process is doing an
1364 				 * execve */
1365 	unsigned in_iowait:1;
1366 
1367 	/* Revert to default priority/policy when forking */
1368 	unsigned sched_reset_on_fork:1;
1369 	unsigned sched_contributes_to_load:1;
1370 
1371 #ifdef CONFIG_MEMCG_KMEM
1372 	unsigned memcg_kmem_skip_account:1;
1373 #endif
1374 
1375 	unsigned long atomic_flags; /* Flags needing atomic access. */
1376 
1377 	struct restart_block restart_block;
1378 
1379 	pid_t pid;
1380 	pid_t tgid;
1381 
1382 #ifdef CONFIG_CC_STACKPROTECTOR
1383 	/* Canary value for the -fstack-protector gcc feature */
1384 	unsigned long stack_canary;
1385 #endif
1386 	/*
1387 	 * pointers to (original) parent process, youngest child, younger sibling,
1388 	 * older sibling, respectively.  (p->father can be replaced with
1389 	 * p->real_parent->pid)
1390 	 */
1391 	struct task_struct __rcu *real_parent; /* real parent process */
1392 	struct task_struct __rcu *parent; /* recipient of SIGCHLD, wait4() reports */
1393 	/*
1394 	 * children/sibling forms the list of my natural children
1395 	 */
1396 	struct list_head children;	/* list of my children */
1397 	struct list_head sibling;	/* linkage in my parent's children list */
1398 	struct task_struct *group_leader;	/* threadgroup leader */
1399 
1400 	/*
1401 	 * ptraced is the list of tasks this task is using ptrace on.
1402 	 * This includes both natural children and PTRACE_ATTACH targets.
1403 	 * p->ptrace_entry is p's link on the p->parent->ptraced list.
1404 	 */
1405 	struct list_head ptraced;
1406 	struct list_head ptrace_entry;
1407 
1408 	/* PID/PID hash table linkage. */
1409 	struct pid_link pids[PIDTYPE_MAX];
1410 	struct list_head thread_group;
1411 	struct list_head thread_node;
1412 
1413 	struct completion *vfork_done;		/* for vfork() */
1414 	int __user *set_child_tid;		/* CLONE_CHILD_SETTID */
1415 	int __user *clear_child_tid;		/* CLONE_CHILD_CLEARTID */
1416 
1417 	cputime_t utime, stime, utimescaled, stimescaled;
1418 	cputime_t gtime;
1419 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
1420 	struct cputime prev_cputime;
1421 #endif
1422 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1423 	seqlock_t vtime_seqlock;
1424 	unsigned long long vtime_snap;
1425 	enum {
1426 		VTIME_SLEEPING = 0,
1427 		VTIME_USER,
1428 		VTIME_SYS,
1429 	} vtime_snap_whence;
1430 #endif
1431 	unsigned long nvcsw, nivcsw; /* context switch counts */
1432 	u64 start_time;		/* monotonic time in nsec */
1433 	u64 real_start_time;	/* boot based time in nsec */
1434 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1435 	unsigned long min_flt, maj_flt;
1436 
1437 	struct task_cputime cputime_expires;
1438 	struct list_head cpu_timers[3];
1439 
1440 /* process credentials */
1441 	const struct cred __rcu *real_cred; /* objective and real subjective task
1442 					 * credentials (COW) */
1443 	const struct cred __rcu *cred;	/* effective (overridable) subjective task
1444 					 * credentials (COW) */
1445 	char comm[TASK_COMM_LEN]; /* executable name excluding path
1446 				     - access with [gs]et_task_comm (which lock
1447 				       it with task_lock())
1448 				     - initialized normally by setup_new_exec */
1449 /* file system info */
1450 	int link_count, total_link_count;
1451 #ifdef CONFIG_SYSVIPC
1452 /* ipc stuff */
1453 	struct sysv_sem sysvsem;
1454 	struct sysv_shm sysvshm;
1455 #endif
1456 #ifdef CONFIG_DETECT_HUNG_TASK
1457 /* hung task detection */
1458 	unsigned long last_switch_count;
1459 #endif
1460 /* CPU-specific state of this task */
1461 	struct thread_struct thread;
1462 /* filesystem information */
1463 	struct fs_struct *fs;
1464 /* open file information */
1465 	struct files_struct *files;
1466 /* namespaces */
1467 	struct nsproxy *nsproxy;
1468 /* signal handlers */
1469 	struct signal_struct *signal;
1470 	struct sighand_struct *sighand;
1471 
1472 	sigset_t blocked, real_blocked;
1473 	sigset_t saved_sigmask;	/* restored if set_restore_sigmask() was used */
1474 	struct sigpending pending;
1475 
1476 	unsigned long sas_ss_sp;
1477 	size_t sas_ss_size;
1478 	int (*notifier)(void *priv);
1479 	void *notifier_data;
1480 	sigset_t *notifier_mask;
1481 	struct callback_head *task_works;
1482 
1483 	struct audit_context *audit_context;
1484 #ifdef CONFIG_AUDITSYSCALL
1485 	kuid_t loginuid;
1486 	unsigned int sessionid;
1487 #endif
1488 	struct seccomp seccomp;
1489 
1490 /* Thread group tracking */
1491    	u32 parent_exec_id;
1492    	u32 self_exec_id;
1493 /* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1494  * mempolicy */
1495 	spinlock_t alloc_lock;
1496 
1497 	/* Protection of the PI data structures: */
1498 	raw_spinlock_t pi_lock;
1499 
1500 #ifdef CONFIG_RT_MUTEXES
1501 	/* PI waiters blocked on a rt_mutex held by this task */
1502 	struct rb_root pi_waiters;
1503 	struct rb_node *pi_waiters_leftmost;
1504 	/* Deadlock detection and priority inheritance handling */
1505 	struct rt_mutex_waiter *pi_blocked_on;
1506 #endif
1507 
1508 #ifdef CONFIG_DEBUG_MUTEXES
1509 	/* mutex deadlock detection */
1510 	struct mutex_waiter *blocked_on;
1511 #endif
1512 #ifdef CONFIG_TRACE_IRQFLAGS
1513 	unsigned int irq_events;
1514 	unsigned long hardirq_enable_ip;
1515 	unsigned long hardirq_disable_ip;
1516 	unsigned int hardirq_enable_event;
1517 	unsigned int hardirq_disable_event;
1518 	int hardirqs_enabled;
1519 	int hardirq_context;
1520 	unsigned long softirq_disable_ip;
1521 	unsigned long softirq_enable_ip;
1522 	unsigned int softirq_disable_event;
1523 	unsigned int softirq_enable_event;
1524 	int softirqs_enabled;
1525 	int softirq_context;
1526 #endif
1527 #ifdef CONFIG_LOCKDEP
1528 # define MAX_LOCK_DEPTH 48UL
1529 	u64 curr_chain_key;
1530 	int lockdep_depth;
1531 	unsigned int lockdep_recursion;
1532 	struct held_lock held_locks[MAX_LOCK_DEPTH];
1533 	gfp_t lockdep_reclaim_gfp;
1534 #endif
1535 
1536 /* journalling filesystem info */
1537 	void *journal_info;
1538 
1539 /* stacked block device info */
1540 	struct bio_list *bio_list;
1541 
1542 #ifdef CONFIG_BLOCK
1543 /* stack plugging */
1544 	struct blk_plug *plug;
1545 #endif
1546 
1547 /* VM state */
1548 	struct reclaim_state *reclaim_state;
1549 
1550 	struct backing_dev_info *backing_dev_info;
1551 
1552 	struct io_context *io_context;
1553 
1554 	unsigned long ptrace_message;
1555 	siginfo_t *last_siginfo; /* For ptrace use.  */
1556 	struct task_io_accounting ioac;
1557 #if defined(CONFIG_TASK_XACCT)
1558 	u64 acct_rss_mem1;	/* accumulated rss usage */
1559 	u64 acct_vm_mem1;	/* accumulated virtual memory usage */
1560 	cputime_t acct_timexpd;	/* stime + utime since last update */
1561 #endif
1562 #ifdef CONFIG_CPUSETS
1563 	nodemask_t mems_allowed;	/* Protected by alloc_lock */
1564 	seqcount_t mems_allowed_seq;	/* Seqence no to catch updates */
1565 	int cpuset_mem_spread_rotor;
1566 	int cpuset_slab_spread_rotor;
1567 #endif
1568 #ifdef CONFIG_CGROUPS
1569 	/* Control Group info protected by css_set_lock */
1570 	struct css_set __rcu *cgroups;
1571 	/* cg_list protected by css_set_lock and tsk->alloc_lock */
1572 	struct list_head cg_list;
1573 #endif
1574 #ifdef CONFIG_FUTEX
1575 	struct robust_list_head __user *robust_list;
1576 #ifdef CONFIG_COMPAT
1577 	struct compat_robust_list_head __user *compat_robust_list;
1578 #endif
1579 	struct list_head pi_state_list;
1580 	struct futex_pi_state *pi_state_cache;
1581 #endif
1582 #ifdef CONFIG_PERF_EVENTS
1583 	struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1584 	struct mutex perf_event_mutex;
1585 	struct list_head perf_event_list;
1586 #endif
1587 #ifdef CONFIG_DEBUG_PREEMPT
1588 	unsigned long preempt_disable_ip;
1589 #endif
1590 #ifdef CONFIG_NUMA
1591 	struct mempolicy *mempolicy;	/* Protected by alloc_lock */
1592 	short il_next;
1593 	short pref_node_fork;
1594 #endif
1595 #ifdef CONFIG_NUMA_BALANCING
1596 	int numa_scan_seq;
1597 	unsigned int numa_scan_period;
1598 	unsigned int numa_scan_period_max;
1599 	int numa_preferred_nid;
1600 	unsigned long numa_migrate_retry;
1601 	u64 node_stamp;			/* migration stamp  */
1602 	u64 last_task_numa_placement;
1603 	u64 last_sum_exec_runtime;
1604 	struct callback_head numa_work;
1605 
1606 	struct list_head numa_entry;
1607 	struct numa_group *numa_group;
1608 
1609 	/*
1610 	 * numa_faults is an array split into four regions:
1611 	 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1612 	 * in this precise order.
1613 	 *
1614 	 * faults_memory: Exponential decaying average of faults on a per-node
1615 	 * basis. Scheduling placement decisions are made based on these
1616 	 * counts. The values remain static for the duration of a PTE scan.
1617 	 * faults_cpu: Track the nodes the process was running on when a NUMA
1618 	 * hinting fault was incurred.
1619 	 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1620 	 * during the current scan window. When the scan completes, the counts
1621 	 * in faults_memory and faults_cpu decay and these values are copied.
1622 	 */
1623 	unsigned long *numa_faults;
1624 	unsigned long total_numa_faults;
1625 
1626 	/*
1627 	 * numa_faults_locality tracks if faults recorded during the last
1628 	 * scan window were remote/local. The task scan period is adapted
1629 	 * based on the locality of the faults with different weights
1630 	 * depending on whether they were shared or private faults
1631 	 */
1632 	unsigned long numa_faults_locality[2];
1633 
1634 	unsigned long numa_pages_migrated;
1635 #endif /* CONFIG_NUMA_BALANCING */
1636 
1637 	struct rcu_head rcu;
1638 
1639 	/*
1640 	 * cache last used pipe for splice
1641 	 */
1642 	struct pipe_inode_info *splice_pipe;
1643 
1644 	struct page_frag task_frag;
1645 
1646 #ifdef	CONFIG_TASK_DELAY_ACCT
1647 	struct task_delay_info *delays;
1648 #endif
1649 #ifdef CONFIG_FAULT_INJECTION
1650 	int make_it_fail;
1651 #endif
1652 	/*
1653 	 * when (nr_dirtied >= nr_dirtied_pause), it's time to call
1654 	 * balance_dirty_pages() for some dirty throttling pause
1655 	 */
1656 	int nr_dirtied;
1657 	int nr_dirtied_pause;
1658 	unsigned long dirty_paused_when; /* start of a write-and-pause period */
1659 
1660 #ifdef CONFIG_LATENCYTOP
1661 	int latency_record_count;
1662 	struct latency_record latency_record[LT_SAVECOUNT];
1663 #endif
1664 	/*
1665 	 * time slack values; these are used to round up poll() and
1666 	 * select() etc timeout values. These are in nanoseconds.
1667 	 */
1668 	unsigned long timer_slack_ns;
1669 	unsigned long default_timer_slack_ns;
1670 
1671 #ifdef CONFIG_KASAN
1672 	unsigned int kasan_depth;
1673 #endif
1674 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1675 	/* Index of current stored address in ret_stack */
1676 	int curr_ret_stack;
1677 	/* Stack of return addresses for return function tracing */
1678 	struct ftrace_ret_stack	*ret_stack;
1679 	/* time stamp for last schedule */
1680 	unsigned long long ftrace_timestamp;
1681 	/*
1682 	 * Number of functions that haven't been traced
1683 	 * because of depth overrun.
1684 	 */
1685 	atomic_t trace_overrun;
1686 	/* Pause for the tracing */
1687 	atomic_t tracing_graph_pause;
1688 #endif
1689 #ifdef CONFIG_TRACING
1690 	/* state flags for use by tracers */
1691 	unsigned long trace;
1692 	/* bitmask and counter of trace recursion */
1693 	unsigned long trace_recursion;
1694 #endif /* CONFIG_TRACING */
1695 #ifdef CONFIG_MEMCG
1696 	struct memcg_oom_info {
1697 		struct mem_cgroup *memcg;
1698 		gfp_t gfp_mask;
1699 		int order;
1700 		unsigned int may_oom:1;
1701 	} memcg_oom;
1702 #endif
1703 #ifdef CONFIG_UPROBES
1704 	struct uprobe_task *utask;
1705 #endif
1706 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1707 	unsigned int	sequential_io;
1708 	unsigned int	sequential_io_avg;
1709 #endif
1710 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1711 	unsigned long	task_state_change;
1712 #endif
1713 };
1714 
1715 /* Future-safe accessor for struct task_struct's cpus_allowed. */
1716 #define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
1717 
1718 #define TNF_MIGRATED	0x01
1719 #define TNF_NO_GROUP	0x02
1720 #define TNF_SHARED	0x04
1721 #define TNF_FAULT_LOCAL	0x08
1722 
1723 #ifdef CONFIG_NUMA_BALANCING
1724 extern void task_numa_fault(int last_node, int node, int pages, int flags);
1725 extern pid_t task_numa_group_id(struct task_struct *p);
1726 extern void set_numabalancing_state(bool enabled);
1727 extern void task_numa_free(struct task_struct *p);
1728 extern bool should_numa_migrate_memory(struct task_struct *p, struct page *page,
1729 					int src_nid, int dst_cpu);
1730 #else
1731 static inline void task_numa_fault(int last_node, int node, int pages,
1732 				   int flags)
1733 {
1734 }
1735 static inline pid_t task_numa_group_id(struct task_struct *p)
1736 {
1737 	return 0;
1738 }
1739 static inline void set_numabalancing_state(bool enabled)
1740 {
1741 }
1742 static inline void task_numa_free(struct task_struct *p)
1743 {
1744 }
1745 static inline bool should_numa_migrate_memory(struct task_struct *p,
1746 				struct page *page, int src_nid, int dst_cpu)
1747 {
1748 	return true;
1749 }
1750 #endif
1751 
1752 static inline struct pid *task_pid(struct task_struct *task)
1753 {
1754 	return task->pids[PIDTYPE_PID].pid;
1755 }
1756 
1757 static inline struct pid *task_tgid(struct task_struct *task)
1758 {
1759 	return task->group_leader->pids[PIDTYPE_PID].pid;
1760 }
1761 
1762 /*
1763  * Without tasklist or rcu lock it is not safe to dereference
1764  * the result of task_pgrp/task_session even if task == current,
1765  * we can race with another thread doing sys_setsid/sys_setpgid.
1766  */
1767 static inline struct pid *task_pgrp(struct task_struct *task)
1768 {
1769 	return task->group_leader->pids[PIDTYPE_PGID].pid;
1770 }
1771 
1772 static inline struct pid *task_session(struct task_struct *task)
1773 {
1774 	return task->group_leader->pids[PIDTYPE_SID].pid;
1775 }
1776 
1777 struct pid_namespace;
1778 
1779 /*
1780  * the helpers to get the task's different pids as they are seen
1781  * from various namespaces
1782  *
1783  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1784  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1785  *                     current.
1786  * task_xid_nr_ns()  : id seen from the ns specified;
1787  *
1788  * set_task_vxid()   : assigns a virtual id to a task;
1789  *
1790  * see also pid_nr() etc in include/linux/pid.h
1791  */
1792 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
1793 			struct pid_namespace *ns);
1794 
1795 static inline pid_t task_pid_nr(struct task_struct *tsk)
1796 {
1797 	return tsk->pid;
1798 }
1799 
1800 static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
1801 					struct pid_namespace *ns)
1802 {
1803 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1804 }
1805 
1806 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1807 {
1808 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1809 }
1810 
1811 
1812 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1813 {
1814 	return tsk->tgid;
1815 }
1816 
1817 pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1818 
1819 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1820 {
1821 	return pid_vnr(task_tgid(tsk));
1822 }
1823 
1824 
1825 static inline int pid_alive(const struct task_struct *p);
1826 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1827 {
1828 	pid_t pid = 0;
1829 
1830 	rcu_read_lock();
1831 	if (pid_alive(tsk))
1832 		pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1833 	rcu_read_unlock();
1834 
1835 	return pid;
1836 }
1837 
1838 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1839 {
1840 	return task_ppid_nr_ns(tsk, &init_pid_ns);
1841 }
1842 
1843 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
1844 					struct pid_namespace *ns)
1845 {
1846 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1847 }
1848 
1849 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1850 {
1851 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1852 }
1853 
1854 
1855 static inline pid_t task_session_nr_ns(struct task_struct *tsk,
1856 					struct pid_namespace *ns)
1857 {
1858 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1859 }
1860 
1861 static inline pid_t task_session_vnr(struct task_struct *tsk)
1862 {
1863 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1864 }
1865 
1866 /* obsolete, do not use */
1867 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1868 {
1869 	return task_pgrp_nr_ns(tsk, &init_pid_ns);
1870 }
1871 
1872 /**
1873  * pid_alive - check that a task structure is not stale
1874  * @p: Task structure to be checked.
1875  *
1876  * Test if a process is not yet dead (at most zombie state)
1877  * If pid_alive fails, then pointers within the task structure
1878  * can be stale and must not be dereferenced.
1879  *
1880  * Return: 1 if the process is alive. 0 otherwise.
1881  */
1882 static inline int pid_alive(const struct task_struct *p)
1883 {
1884 	return p->pids[PIDTYPE_PID].pid != NULL;
1885 }
1886 
1887 /**
1888  * is_global_init - check if a task structure is init
1889  * @tsk: Task structure to be checked.
1890  *
1891  * Check if a task structure is the first user space task the kernel created.
1892  *
1893  * Return: 1 if the task structure is init. 0 otherwise.
1894  */
1895 static inline int is_global_init(struct task_struct *tsk)
1896 {
1897 	return tsk->pid == 1;
1898 }
1899 
1900 extern struct pid *cad_pid;
1901 
1902 extern void free_task(struct task_struct *tsk);
1903 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
1904 
1905 extern void __put_task_struct(struct task_struct *t);
1906 
1907 static inline void put_task_struct(struct task_struct *t)
1908 {
1909 	if (atomic_dec_and_test(&t->usage))
1910 		__put_task_struct(t);
1911 }
1912 
1913 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1914 extern void task_cputime(struct task_struct *t,
1915 			 cputime_t *utime, cputime_t *stime);
1916 extern void task_cputime_scaled(struct task_struct *t,
1917 				cputime_t *utimescaled, cputime_t *stimescaled);
1918 extern cputime_t task_gtime(struct task_struct *t);
1919 #else
1920 static inline void task_cputime(struct task_struct *t,
1921 				cputime_t *utime, cputime_t *stime)
1922 {
1923 	if (utime)
1924 		*utime = t->utime;
1925 	if (stime)
1926 		*stime = t->stime;
1927 }
1928 
1929 static inline void task_cputime_scaled(struct task_struct *t,
1930 				       cputime_t *utimescaled,
1931 				       cputime_t *stimescaled)
1932 {
1933 	if (utimescaled)
1934 		*utimescaled = t->utimescaled;
1935 	if (stimescaled)
1936 		*stimescaled = t->stimescaled;
1937 }
1938 
1939 static inline cputime_t task_gtime(struct task_struct *t)
1940 {
1941 	return t->gtime;
1942 }
1943 #endif
1944 extern void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
1945 extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
1946 
1947 /*
1948  * Per process flags
1949  */
1950 #define PF_EXITING	0x00000004	/* getting shut down */
1951 #define PF_EXITPIDONE	0x00000008	/* pi exit done on shut down */
1952 #define PF_VCPU		0x00000010	/* I'm a virtual CPU */
1953 #define PF_WQ_WORKER	0x00000020	/* I'm a workqueue worker */
1954 #define PF_FORKNOEXEC	0x00000040	/* forked but didn't exec */
1955 #define PF_MCE_PROCESS  0x00000080      /* process policy on mce errors */
1956 #define PF_SUPERPRIV	0x00000100	/* used super-user privileges */
1957 #define PF_DUMPCORE	0x00000200	/* dumped core */
1958 #define PF_SIGNALED	0x00000400	/* killed by a signal */
1959 #define PF_MEMALLOC	0x00000800	/* Allocating memory */
1960 #define PF_NPROC_EXCEEDED 0x00001000	/* set_user noticed that RLIMIT_NPROC was exceeded */
1961 #define PF_USED_MATH	0x00002000	/* if unset the fpu must be initialized before use */
1962 #define PF_USED_ASYNC	0x00004000	/* used async_schedule*(), used by module init */
1963 #define PF_NOFREEZE	0x00008000	/* this thread should not be frozen */
1964 #define PF_FROZEN	0x00010000	/* frozen for system suspend */
1965 #define PF_FSTRANS	0x00020000	/* inside a filesystem transaction */
1966 #define PF_KSWAPD	0x00040000	/* I am kswapd */
1967 #define PF_MEMALLOC_NOIO 0x00080000	/* Allocating memory without IO involved */
1968 #define PF_LESS_THROTTLE 0x00100000	/* Throttle me less: I clean memory */
1969 #define PF_KTHREAD	0x00200000	/* I am a kernel thread */
1970 #define PF_RANDOMIZE	0x00400000	/* randomize virtual address space */
1971 #define PF_SWAPWRITE	0x00800000	/* Allowed to write to swap */
1972 #define PF_NO_SETAFFINITY 0x04000000	/* Userland is not allowed to meddle with cpus_allowed */
1973 #define PF_MCE_EARLY    0x08000000      /* Early kill for mce process policy */
1974 #define PF_MUTEX_TESTER	0x20000000	/* Thread belongs to the rt mutex tester */
1975 #define PF_FREEZER_SKIP	0x40000000	/* Freezer should not count it as freezable */
1976 #define PF_SUSPEND_TASK 0x80000000      /* this thread called freeze_processes and should not be frozen */
1977 
1978 /*
1979  * Only the _current_ task can read/write to tsk->flags, but other
1980  * tasks can access tsk->flags in readonly mode for example
1981  * with tsk_used_math (like during threaded core dumping).
1982  * There is however an exception to this rule during ptrace
1983  * or during fork: the ptracer task is allowed to write to the
1984  * child->flags of its traced child (same goes for fork, the parent
1985  * can write to the child->flags), because we're guaranteed the
1986  * child is not running and in turn not changing child->flags
1987  * at the same time the parent does it.
1988  */
1989 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1990 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1991 #define clear_used_math() clear_stopped_child_used_math(current)
1992 #define set_used_math() set_stopped_child_used_math(current)
1993 #define conditional_stopped_child_used_math(condition, child) \
1994 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1995 #define conditional_used_math(condition) \
1996 	conditional_stopped_child_used_math(condition, current)
1997 #define copy_to_stopped_child_used_math(child) \
1998 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1999 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
2000 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
2001 #define used_math() tsk_used_math(current)
2002 
2003 /* __GFP_IO isn't allowed if PF_MEMALLOC_NOIO is set in current->flags
2004  * __GFP_FS is also cleared as it implies __GFP_IO.
2005  */
2006 static inline gfp_t memalloc_noio_flags(gfp_t flags)
2007 {
2008 	if (unlikely(current->flags & PF_MEMALLOC_NOIO))
2009 		flags &= ~(__GFP_IO | __GFP_FS);
2010 	return flags;
2011 }
2012 
2013 static inline unsigned int memalloc_noio_save(void)
2014 {
2015 	unsigned int flags = current->flags & PF_MEMALLOC_NOIO;
2016 	current->flags |= PF_MEMALLOC_NOIO;
2017 	return flags;
2018 }
2019 
2020 static inline void memalloc_noio_restore(unsigned int flags)
2021 {
2022 	current->flags = (current->flags & ~PF_MEMALLOC_NOIO) | flags;
2023 }
2024 
2025 /* Per-process atomic flags. */
2026 #define PFA_NO_NEW_PRIVS 0	/* May not gain new privileges. */
2027 #define PFA_SPREAD_PAGE  1      /* Spread page cache over cpuset */
2028 #define PFA_SPREAD_SLAB  2      /* Spread some slab caches over cpuset */
2029 
2030 
2031 #define TASK_PFA_TEST(name, func)					\
2032 	static inline bool task_##func(struct task_struct *p)		\
2033 	{ return test_bit(PFA_##name, &p->atomic_flags); }
2034 #define TASK_PFA_SET(name, func)					\
2035 	static inline void task_set_##func(struct task_struct *p)	\
2036 	{ set_bit(PFA_##name, &p->atomic_flags); }
2037 #define TASK_PFA_CLEAR(name, func)					\
2038 	static inline void task_clear_##func(struct task_struct *p)	\
2039 	{ clear_bit(PFA_##name, &p->atomic_flags); }
2040 
2041 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
2042 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
2043 
2044 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
2045 TASK_PFA_SET(SPREAD_PAGE, spread_page)
2046 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
2047 
2048 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
2049 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
2050 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
2051 
2052 /*
2053  * task->jobctl flags
2054  */
2055 #define JOBCTL_STOP_SIGMASK	0xffff	/* signr of the last group stop */
2056 
2057 #define JOBCTL_STOP_DEQUEUED_BIT 16	/* stop signal dequeued */
2058 #define JOBCTL_STOP_PENDING_BIT	17	/* task should stop for group stop */
2059 #define JOBCTL_STOP_CONSUME_BIT	18	/* consume group stop count */
2060 #define JOBCTL_TRAP_STOP_BIT	19	/* trap for STOP */
2061 #define JOBCTL_TRAP_NOTIFY_BIT	20	/* trap for NOTIFY */
2062 #define JOBCTL_TRAPPING_BIT	21	/* switching to TRACED */
2063 #define JOBCTL_LISTENING_BIT	22	/* ptracer is listening for events */
2064 
2065 #define JOBCTL_STOP_DEQUEUED	(1 << JOBCTL_STOP_DEQUEUED_BIT)
2066 #define JOBCTL_STOP_PENDING	(1 << JOBCTL_STOP_PENDING_BIT)
2067 #define JOBCTL_STOP_CONSUME	(1 << JOBCTL_STOP_CONSUME_BIT)
2068 #define JOBCTL_TRAP_STOP	(1 << JOBCTL_TRAP_STOP_BIT)
2069 #define JOBCTL_TRAP_NOTIFY	(1 << JOBCTL_TRAP_NOTIFY_BIT)
2070 #define JOBCTL_TRAPPING		(1 << JOBCTL_TRAPPING_BIT)
2071 #define JOBCTL_LISTENING	(1 << JOBCTL_LISTENING_BIT)
2072 
2073 #define JOBCTL_TRAP_MASK	(JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
2074 #define JOBCTL_PENDING_MASK	(JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)
2075 
2076 extern bool task_set_jobctl_pending(struct task_struct *task,
2077 				    unsigned int mask);
2078 extern void task_clear_jobctl_trapping(struct task_struct *task);
2079 extern void task_clear_jobctl_pending(struct task_struct *task,
2080 				      unsigned int mask);
2081 
2082 static inline void rcu_copy_process(struct task_struct *p)
2083 {
2084 #ifdef CONFIG_PREEMPT_RCU
2085 	p->rcu_read_lock_nesting = 0;
2086 	p->rcu_read_unlock_special.s = 0;
2087 	p->rcu_blocked_node = NULL;
2088 	INIT_LIST_HEAD(&p->rcu_node_entry);
2089 #endif /* #ifdef CONFIG_PREEMPT_RCU */
2090 #ifdef CONFIG_TASKS_RCU
2091 	p->rcu_tasks_holdout = false;
2092 	INIT_LIST_HEAD(&p->rcu_tasks_holdout_list);
2093 	p->rcu_tasks_idle_cpu = -1;
2094 #endif /* #ifdef CONFIG_TASKS_RCU */
2095 }
2096 
2097 static inline void tsk_restore_flags(struct task_struct *task,
2098 				unsigned long orig_flags, unsigned long flags)
2099 {
2100 	task->flags &= ~flags;
2101 	task->flags |= orig_flags & flags;
2102 }
2103 
2104 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur,
2105 				     const struct cpumask *trial);
2106 extern int task_can_attach(struct task_struct *p,
2107 			   const struct cpumask *cs_cpus_allowed);
2108 #ifdef CONFIG_SMP
2109 extern void do_set_cpus_allowed(struct task_struct *p,
2110 			       const struct cpumask *new_mask);
2111 
2112 extern int set_cpus_allowed_ptr(struct task_struct *p,
2113 				const struct cpumask *new_mask);
2114 #else
2115 static inline void do_set_cpus_allowed(struct task_struct *p,
2116 				      const struct cpumask *new_mask)
2117 {
2118 }
2119 static inline int set_cpus_allowed_ptr(struct task_struct *p,
2120 				       const struct cpumask *new_mask)
2121 {
2122 	if (!cpumask_test_cpu(0, new_mask))
2123 		return -EINVAL;
2124 	return 0;
2125 }
2126 #endif
2127 
2128 #ifdef CONFIG_NO_HZ_COMMON
2129 void calc_load_enter_idle(void);
2130 void calc_load_exit_idle(void);
2131 #else
2132 static inline void calc_load_enter_idle(void) { }
2133 static inline void calc_load_exit_idle(void) { }
2134 #endif /* CONFIG_NO_HZ_COMMON */
2135 
2136 #ifndef CONFIG_CPUMASK_OFFSTACK
2137 static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
2138 {
2139 	return set_cpus_allowed_ptr(p, &new_mask);
2140 }
2141 #endif
2142 
2143 /*
2144  * Do not use outside of architecture code which knows its limitations.
2145  *
2146  * sched_clock() has no promise of monotonicity or bounded drift between
2147  * CPUs, use (which you should not) requires disabling IRQs.
2148  *
2149  * Please use one of the three interfaces below.
2150  */
2151 extern unsigned long long notrace sched_clock(void);
2152 /*
2153  * See the comment in kernel/sched/clock.c
2154  */
2155 extern u64 cpu_clock(int cpu);
2156 extern u64 local_clock(void);
2157 extern u64 running_clock(void);
2158 extern u64 sched_clock_cpu(int cpu);
2159 
2160 
2161 extern void sched_clock_init(void);
2162 
2163 #ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
2164 static inline void sched_clock_tick(void)
2165 {
2166 }
2167 
2168 static inline void sched_clock_idle_sleep_event(void)
2169 {
2170 }
2171 
2172 static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
2173 {
2174 }
2175 #else
2176 /*
2177  * Architectures can set this to 1 if they have specified
2178  * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
2179  * but then during bootup it turns out that sched_clock()
2180  * is reliable after all:
2181  */
2182 extern int sched_clock_stable(void);
2183 extern void set_sched_clock_stable(void);
2184 extern void clear_sched_clock_stable(void);
2185 
2186 extern void sched_clock_tick(void);
2187 extern void sched_clock_idle_sleep_event(void);
2188 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2189 #endif
2190 
2191 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
2192 /*
2193  * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
2194  * The reason for this explicit opt-in is not to have perf penalty with
2195  * slow sched_clocks.
2196  */
2197 extern void enable_sched_clock_irqtime(void);
2198 extern void disable_sched_clock_irqtime(void);
2199 #else
2200 static inline void enable_sched_clock_irqtime(void) {}
2201 static inline void disable_sched_clock_irqtime(void) {}
2202 #endif
2203 
2204 extern unsigned long long
2205 task_sched_runtime(struct task_struct *task);
2206 
2207 /* sched_exec is called by processes performing an exec */
2208 #ifdef CONFIG_SMP
2209 extern void sched_exec(void);
2210 #else
2211 #define sched_exec()   {}
2212 #endif
2213 
2214 extern void sched_clock_idle_sleep_event(void);
2215 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2216 
2217 #ifdef CONFIG_HOTPLUG_CPU
2218 extern void idle_task_exit(void);
2219 #else
2220 static inline void idle_task_exit(void) {}
2221 #endif
2222 
2223 #if defined(CONFIG_NO_HZ_COMMON) && defined(CONFIG_SMP)
2224 extern void wake_up_nohz_cpu(int cpu);
2225 #else
2226 static inline void wake_up_nohz_cpu(int cpu) { }
2227 #endif
2228 
2229 #ifdef CONFIG_NO_HZ_FULL
2230 extern bool sched_can_stop_tick(void);
2231 extern u64 scheduler_tick_max_deferment(void);
2232 #else
2233 static inline bool sched_can_stop_tick(void) { return false; }
2234 #endif
2235 
2236 #ifdef CONFIG_SCHED_AUTOGROUP
2237 extern void sched_autogroup_create_attach(struct task_struct *p);
2238 extern void sched_autogroup_detach(struct task_struct *p);
2239 extern void sched_autogroup_fork(struct signal_struct *sig);
2240 extern void sched_autogroup_exit(struct signal_struct *sig);
2241 #ifdef CONFIG_PROC_FS
2242 extern void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m);
2243 extern int proc_sched_autogroup_set_nice(struct task_struct *p, int nice);
2244 #endif
2245 #else
2246 static inline void sched_autogroup_create_attach(struct task_struct *p) { }
2247 static inline void sched_autogroup_detach(struct task_struct *p) { }
2248 static inline void sched_autogroup_fork(struct signal_struct *sig) { }
2249 static inline void sched_autogroup_exit(struct signal_struct *sig) { }
2250 #endif
2251 
2252 extern int yield_to(struct task_struct *p, bool preempt);
2253 extern void set_user_nice(struct task_struct *p, long nice);
2254 extern int task_prio(const struct task_struct *p);
2255 /**
2256  * task_nice - return the nice value of a given task.
2257  * @p: the task in question.
2258  *
2259  * Return: The nice value [ -20 ... 0 ... 19 ].
2260  */
2261 static inline int task_nice(const struct task_struct *p)
2262 {
2263 	return PRIO_TO_NICE((p)->static_prio);
2264 }
2265 extern int can_nice(const struct task_struct *p, const int nice);
2266 extern int task_curr(const struct task_struct *p);
2267 extern int idle_cpu(int cpu);
2268 extern int sched_setscheduler(struct task_struct *, int,
2269 			      const struct sched_param *);
2270 extern int sched_setscheduler_nocheck(struct task_struct *, int,
2271 				      const struct sched_param *);
2272 extern int sched_setattr(struct task_struct *,
2273 			 const struct sched_attr *);
2274 extern struct task_struct *idle_task(int cpu);
2275 /**
2276  * is_idle_task - is the specified task an idle task?
2277  * @p: the task in question.
2278  *
2279  * Return: 1 if @p is an idle task. 0 otherwise.
2280  */
2281 static inline bool is_idle_task(const struct task_struct *p)
2282 {
2283 	return p->pid == 0;
2284 }
2285 extern struct task_struct *curr_task(int cpu);
2286 extern void set_curr_task(int cpu, struct task_struct *p);
2287 
2288 void yield(void);
2289 
2290 /*
2291  * The default (Linux) execution domain.
2292  */
2293 extern struct exec_domain	default_exec_domain;
2294 
2295 union thread_union {
2296 	struct thread_info thread_info;
2297 	unsigned long stack[THREAD_SIZE/sizeof(long)];
2298 };
2299 
2300 #ifndef __HAVE_ARCH_KSTACK_END
2301 static inline int kstack_end(void *addr)
2302 {
2303 	/* Reliable end of stack detection:
2304 	 * Some APM bios versions misalign the stack
2305 	 */
2306 	return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
2307 }
2308 #endif
2309 
2310 extern union thread_union init_thread_union;
2311 extern struct task_struct init_task;
2312 
2313 extern struct   mm_struct init_mm;
2314 
2315 extern struct pid_namespace init_pid_ns;
2316 
2317 /*
2318  * find a task by one of its numerical ids
2319  *
2320  * find_task_by_pid_ns():
2321  *      finds a task by its pid in the specified namespace
2322  * find_task_by_vpid():
2323  *      finds a task by its virtual pid
2324  *
2325  * see also find_vpid() etc in include/linux/pid.h
2326  */
2327 
2328 extern struct task_struct *find_task_by_vpid(pid_t nr);
2329 extern struct task_struct *find_task_by_pid_ns(pid_t nr,
2330 		struct pid_namespace *ns);
2331 
2332 /* per-UID process charging. */
2333 extern struct user_struct * alloc_uid(kuid_t);
2334 static inline struct user_struct *get_uid(struct user_struct *u)
2335 {
2336 	atomic_inc(&u->__count);
2337 	return u;
2338 }
2339 extern void free_uid(struct user_struct *);
2340 
2341 #include <asm/current.h>
2342 
2343 extern void xtime_update(unsigned long ticks);
2344 
2345 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2346 extern int wake_up_process(struct task_struct *tsk);
2347 extern void wake_up_new_task(struct task_struct *tsk);
2348 #ifdef CONFIG_SMP
2349  extern void kick_process(struct task_struct *tsk);
2350 #else
2351  static inline void kick_process(struct task_struct *tsk) { }
2352 #endif
2353 extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
2354 extern void sched_dead(struct task_struct *p);
2355 
2356 extern void proc_caches_init(void);
2357 extern void flush_signals(struct task_struct *);
2358 extern void __flush_signals(struct task_struct *);
2359 extern void ignore_signals(struct task_struct *);
2360 extern void flush_signal_handlers(struct task_struct *, int force_default);
2361 extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
2362 
2363 static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
2364 {
2365 	unsigned long flags;
2366 	int ret;
2367 
2368 	spin_lock_irqsave(&tsk->sighand->siglock, flags);
2369 	ret = dequeue_signal(tsk, mask, info);
2370 	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
2371 
2372 	return ret;
2373 }
2374 
2375 extern void block_all_signals(int (*notifier)(void *priv), void *priv,
2376 			      sigset_t *mask);
2377 extern void unblock_all_signals(void);
2378 extern void release_task(struct task_struct * p);
2379 extern int send_sig_info(int, struct siginfo *, struct task_struct *);
2380 extern int force_sigsegv(int, struct task_struct *);
2381 extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2382 extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
2383 extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2384 extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *,
2385 				const struct cred *, u32);
2386 extern int kill_pgrp(struct pid *pid, int sig, int priv);
2387 extern int kill_pid(struct pid *pid, int sig, int priv);
2388 extern int kill_proc_info(int, struct siginfo *, pid_t);
2389 extern __must_check bool do_notify_parent(struct task_struct *, int);
2390 extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
2391 extern void force_sig(int, struct task_struct *);
2392 extern int send_sig(int, struct task_struct *, int);
2393 extern int zap_other_threads(struct task_struct *p);
2394 extern struct sigqueue *sigqueue_alloc(void);
2395 extern void sigqueue_free(struct sigqueue *);
2396 extern int send_sigqueue(struct sigqueue *,  struct task_struct *, int group);
2397 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
2398 
2399 static inline void restore_saved_sigmask(void)
2400 {
2401 	if (test_and_clear_restore_sigmask())
2402 		__set_current_blocked(&current->saved_sigmask);
2403 }
2404 
2405 static inline sigset_t *sigmask_to_save(void)
2406 {
2407 	sigset_t *res = &current->blocked;
2408 	if (unlikely(test_restore_sigmask()))
2409 		res = &current->saved_sigmask;
2410 	return res;
2411 }
2412 
2413 static inline int kill_cad_pid(int sig, int priv)
2414 {
2415 	return kill_pid(cad_pid, sig, priv);
2416 }
2417 
2418 /* These can be the second arg to send_sig_info/send_group_sig_info.  */
2419 #define SEND_SIG_NOINFO ((struct siginfo *) 0)
2420 #define SEND_SIG_PRIV	((struct siginfo *) 1)
2421 #define SEND_SIG_FORCED	((struct siginfo *) 2)
2422 
2423 /*
2424  * True if we are on the alternate signal stack.
2425  */
2426 static inline int on_sig_stack(unsigned long sp)
2427 {
2428 #ifdef CONFIG_STACK_GROWSUP
2429 	return sp >= current->sas_ss_sp &&
2430 		sp - current->sas_ss_sp < current->sas_ss_size;
2431 #else
2432 	return sp > current->sas_ss_sp &&
2433 		sp - current->sas_ss_sp <= current->sas_ss_size;
2434 #endif
2435 }
2436 
2437 static inline int sas_ss_flags(unsigned long sp)
2438 {
2439 	if (!current->sas_ss_size)
2440 		return SS_DISABLE;
2441 
2442 	return on_sig_stack(sp) ? SS_ONSTACK : 0;
2443 }
2444 
2445 static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig)
2446 {
2447 	if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))
2448 #ifdef CONFIG_STACK_GROWSUP
2449 		return current->sas_ss_sp;
2450 #else
2451 		return current->sas_ss_sp + current->sas_ss_size;
2452 #endif
2453 	return sp;
2454 }
2455 
2456 /*
2457  * Routines for handling mm_structs
2458  */
2459 extern struct mm_struct * mm_alloc(void);
2460 
2461 /* mmdrop drops the mm and the page tables */
2462 extern void __mmdrop(struct mm_struct *);
2463 static inline void mmdrop(struct mm_struct * mm)
2464 {
2465 	if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2466 		__mmdrop(mm);
2467 }
2468 
2469 /* mmput gets rid of the mappings and all user-space */
2470 extern void mmput(struct mm_struct *);
2471 /* Grab a reference to a task's mm, if it is not already going away */
2472 extern struct mm_struct *get_task_mm(struct task_struct *task);
2473 /*
2474  * Grab a reference to a task's mm, if it is not already going away
2475  * and ptrace_may_access with the mode parameter passed to it
2476  * succeeds.
2477  */
2478 extern struct mm_struct *mm_access(struct task_struct *task, unsigned int mode);
2479 /* Remove the current tasks stale references to the old mm_struct */
2480 extern void mm_release(struct task_struct *, struct mm_struct *);
2481 
2482 extern int copy_thread(unsigned long, unsigned long, unsigned long,
2483 			struct task_struct *);
2484 extern void flush_thread(void);
2485 extern void exit_thread(void);
2486 
2487 extern void exit_files(struct task_struct *);
2488 extern void __cleanup_sighand(struct sighand_struct *);
2489 
2490 extern void exit_itimers(struct signal_struct *);
2491 extern void flush_itimer_signals(void);
2492 
2493 extern void do_group_exit(int);
2494 
2495 extern int do_execve(struct filename *,
2496 		     const char __user * const __user *,
2497 		     const char __user * const __user *);
2498 extern int do_execveat(int, struct filename *,
2499 		       const char __user * const __user *,
2500 		       const char __user * const __user *,
2501 		       int);
2502 extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
2503 struct task_struct *fork_idle(int);
2504 extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
2505 
2506 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
2507 static inline void set_task_comm(struct task_struct *tsk, const char *from)
2508 {
2509 	__set_task_comm(tsk, from, false);
2510 }
2511 extern char *get_task_comm(char *to, struct task_struct *tsk);
2512 
2513 #ifdef CONFIG_SMP
2514 void scheduler_ipi(void);
2515 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
2516 #else
2517 static inline void scheduler_ipi(void) { }
2518 static inline unsigned long wait_task_inactive(struct task_struct *p,
2519 					       long match_state)
2520 {
2521 	return 1;
2522 }
2523 #endif
2524 
2525 #define next_task(p) \
2526 	list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
2527 
2528 #define for_each_process(p) \
2529 	for (p = &init_task ; (p = next_task(p)) != &init_task ; )
2530 
2531 extern bool current_is_single_threaded(void);
2532 
2533 /*
2534  * Careful: do_each_thread/while_each_thread is a double loop so
2535  *          'break' will not work as expected - use goto instead.
2536  */
2537 #define do_each_thread(g, t) \
2538 	for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
2539 
2540 #define while_each_thread(g, t) \
2541 	while ((t = next_thread(t)) != g)
2542 
2543 #define __for_each_thread(signal, t)	\
2544 	list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node)
2545 
2546 #define for_each_thread(p, t)		\
2547 	__for_each_thread((p)->signal, t)
2548 
2549 /* Careful: this is a double loop, 'break' won't work as expected. */
2550 #define for_each_process_thread(p, t)	\
2551 	for_each_process(p) for_each_thread(p, t)
2552 
2553 static inline int get_nr_threads(struct task_struct *tsk)
2554 {
2555 	return tsk->signal->nr_threads;
2556 }
2557 
2558 static inline bool thread_group_leader(struct task_struct *p)
2559 {
2560 	return p->exit_signal >= 0;
2561 }
2562 
2563 /* Do to the insanities of de_thread it is possible for a process
2564  * to have the pid of the thread group leader without actually being
2565  * the thread group leader.  For iteration through the pids in proc
2566  * all we care about is that we have a task with the appropriate
2567  * pid, we don't actually care if we have the right task.
2568  */
2569 static inline bool has_group_leader_pid(struct task_struct *p)
2570 {
2571 	return task_pid(p) == p->signal->leader_pid;
2572 }
2573 
2574 static inline
2575 bool same_thread_group(struct task_struct *p1, struct task_struct *p2)
2576 {
2577 	return p1->signal == p2->signal;
2578 }
2579 
2580 static inline struct task_struct *next_thread(const struct task_struct *p)
2581 {
2582 	return list_entry_rcu(p->thread_group.next,
2583 			      struct task_struct, thread_group);
2584 }
2585 
2586 static inline int thread_group_empty(struct task_struct *p)
2587 {
2588 	return list_empty(&p->thread_group);
2589 }
2590 
2591 #define delay_group_leader(p) \
2592 		(thread_group_leader(p) && !thread_group_empty(p))
2593 
2594 /*
2595  * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
2596  * subscriptions and synchronises with wait4().  Also used in procfs.  Also
2597  * pins the final release of task.io_context.  Also protects ->cpuset and
2598  * ->cgroup.subsys[]. And ->vfork_done.
2599  *
2600  * Nests both inside and outside of read_lock(&tasklist_lock).
2601  * It must not be nested with write_lock_irq(&tasklist_lock),
2602  * neither inside nor outside.
2603  */
2604 static inline void task_lock(struct task_struct *p)
2605 {
2606 	spin_lock(&p->alloc_lock);
2607 }
2608 
2609 static inline void task_unlock(struct task_struct *p)
2610 {
2611 	spin_unlock(&p->alloc_lock);
2612 }
2613 
2614 extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
2615 							unsigned long *flags);
2616 
2617 static inline struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
2618 						       unsigned long *flags)
2619 {
2620 	struct sighand_struct *ret;
2621 
2622 	ret = __lock_task_sighand(tsk, flags);
2623 	(void)__cond_lock(&tsk->sighand->siglock, ret);
2624 	return ret;
2625 }
2626 
2627 static inline void unlock_task_sighand(struct task_struct *tsk,
2628 						unsigned long *flags)
2629 {
2630 	spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
2631 }
2632 
2633 #ifdef CONFIG_CGROUPS
2634 static inline void threadgroup_change_begin(struct task_struct *tsk)
2635 {
2636 	down_read(&tsk->signal->group_rwsem);
2637 }
2638 static inline void threadgroup_change_end(struct task_struct *tsk)
2639 {
2640 	up_read(&tsk->signal->group_rwsem);
2641 }
2642 
2643 /**
2644  * threadgroup_lock - lock threadgroup
2645  * @tsk: member task of the threadgroup to lock
2646  *
2647  * Lock the threadgroup @tsk belongs to.  No new task is allowed to enter
2648  * and member tasks aren't allowed to exit (as indicated by PF_EXITING) or
2649  * change ->group_leader/pid.  This is useful for cases where the threadgroup
2650  * needs to stay stable across blockable operations.
2651  *
2652  * fork and exit paths explicitly call threadgroup_change_{begin|end}() for
2653  * synchronization.  While held, no new task will be added to threadgroup
2654  * and no existing live task will have its PF_EXITING set.
2655  *
2656  * de_thread() does threadgroup_change_{begin|end}() when a non-leader
2657  * sub-thread becomes a new leader.
2658  */
2659 static inline void threadgroup_lock(struct task_struct *tsk)
2660 {
2661 	down_write(&tsk->signal->group_rwsem);
2662 }
2663 
2664 /**
2665  * threadgroup_unlock - unlock threadgroup
2666  * @tsk: member task of the threadgroup to unlock
2667  *
2668  * Reverse threadgroup_lock().
2669  */
2670 static inline void threadgroup_unlock(struct task_struct *tsk)
2671 {
2672 	up_write(&tsk->signal->group_rwsem);
2673 }
2674 #else
2675 static inline void threadgroup_change_begin(struct task_struct *tsk) {}
2676 static inline void threadgroup_change_end(struct task_struct *tsk) {}
2677 static inline void threadgroup_lock(struct task_struct *tsk) {}
2678 static inline void threadgroup_unlock(struct task_struct *tsk) {}
2679 #endif
2680 
2681 #ifndef __HAVE_THREAD_FUNCTIONS
2682 
2683 #define task_thread_info(task)	((struct thread_info *)(task)->stack)
2684 #define task_stack_page(task)	((task)->stack)
2685 
2686 static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
2687 {
2688 	*task_thread_info(p) = *task_thread_info(org);
2689 	task_thread_info(p)->task = p;
2690 }
2691 
2692 /*
2693  * Return the address of the last usable long on the stack.
2694  *
2695  * When the stack grows down, this is just above the thread
2696  * info struct. Going any lower will corrupt the threadinfo.
2697  *
2698  * When the stack grows up, this is the highest address.
2699  * Beyond that position, we corrupt data on the next page.
2700  */
2701 static inline unsigned long *end_of_stack(struct task_struct *p)
2702 {
2703 #ifdef CONFIG_STACK_GROWSUP
2704 	return (unsigned long *)((unsigned long)task_thread_info(p) + THREAD_SIZE) - 1;
2705 #else
2706 	return (unsigned long *)(task_thread_info(p) + 1);
2707 #endif
2708 }
2709 
2710 #endif
2711 #define task_stack_end_corrupted(task) \
2712 		(*(end_of_stack(task)) != STACK_END_MAGIC)
2713 
2714 static inline int object_is_on_stack(void *obj)
2715 {
2716 	void *stack = task_stack_page(current);
2717 
2718 	return (obj >= stack) && (obj < (stack + THREAD_SIZE));
2719 }
2720 
2721 extern void thread_info_cache_init(void);
2722 
2723 #ifdef CONFIG_DEBUG_STACK_USAGE
2724 static inline unsigned long stack_not_used(struct task_struct *p)
2725 {
2726 	unsigned long *n = end_of_stack(p);
2727 
2728 	do { 	/* Skip over canary */
2729 		n++;
2730 	} while (!*n);
2731 
2732 	return (unsigned long)n - (unsigned long)end_of_stack(p);
2733 }
2734 #endif
2735 extern void set_task_stack_end_magic(struct task_struct *tsk);
2736 
2737 /* set thread flags in other task's structures
2738  * - see asm/thread_info.h for TIF_xxxx flags available
2739  */
2740 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2741 {
2742 	set_ti_thread_flag(task_thread_info(tsk), flag);
2743 }
2744 
2745 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2746 {
2747 	clear_ti_thread_flag(task_thread_info(tsk), flag);
2748 }
2749 
2750 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2751 {
2752 	return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2753 }
2754 
2755 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2756 {
2757 	return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2758 }
2759 
2760 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2761 {
2762 	return test_ti_thread_flag(task_thread_info(tsk), flag);
2763 }
2764 
2765 static inline void set_tsk_need_resched(struct task_struct *tsk)
2766 {
2767 	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2768 }
2769 
2770 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2771 {
2772 	clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2773 }
2774 
2775 static inline int test_tsk_need_resched(struct task_struct *tsk)
2776 {
2777 	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2778 }
2779 
2780 static inline int restart_syscall(void)
2781 {
2782 	set_tsk_thread_flag(current, TIF_SIGPENDING);
2783 	return -ERESTARTNOINTR;
2784 }
2785 
2786 static inline int signal_pending(struct task_struct *p)
2787 {
2788 	return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
2789 }
2790 
2791 static inline int __fatal_signal_pending(struct task_struct *p)
2792 {
2793 	return unlikely(sigismember(&p->pending.signal, SIGKILL));
2794 }
2795 
2796 static inline int fatal_signal_pending(struct task_struct *p)
2797 {
2798 	return signal_pending(p) && __fatal_signal_pending(p);
2799 }
2800 
2801 static inline int signal_pending_state(long state, struct task_struct *p)
2802 {
2803 	if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
2804 		return 0;
2805 	if (!signal_pending(p))
2806 		return 0;
2807 
2808 	return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
2809 }
2810 
2811 /*
2812  * cond_resched() and cond_resched_lock(): latency reduction via
2813  * explicit rescheduling in places that are safe. The return
2814  * value indicates whether a reschedule was done in fact.
2815  * cond_resched_lock() will drop the spinlock before scheduling,
2816  * cond_resched_softirq() will enable bhs before scheduling.
2817  */
2818 extern int _cond_resched(void);
2819 
2820 #define cond_resched() ({			\
2821 	___might_sleep(__FILE__, __LINE__, 0);	\
2822 	_cond_resched();			\
2823 })
2824 
2825 extern int __cond_resched_lock(spinlock_t *lock);
2826 
2827 #ifdef CONFIG_PREEMPT_COUNT
2828 #define PREEMPT_LOCK_OFFSET	PREEMPT_OFFSET
2829 #else
2830 #define PREEMPT_LOCK_OFFSET	0
2831 #endif
2832 
2833 #define cond_resched_lock(lock) ({				\
2834 	___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
2835 	__cond_resched_lock(lock);				\
2836 })
2837 
2838 extern int __cond_resched_softirq(void);
2839 
2840 #define cond_resched_softirq() ({					\
2841 	___might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET);	\
2842 	__cond_resched_softirq();					\
2843 })
2844 
2845 static inline void cond_resched_rcu(void)
2846 {
2847 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
2848 	rcu_read_unlock();
2849 	cond_resched();
2850 	rcu_read_lock();
2851 #endif
2852 }
2853 
2854 /*
2855  * Does a critical section need to be broken due to another
2856  * task waiting?: (technically does not depend on CONFIG_PREEMPT,
2857  * but a general need for low latency)
2858  */
2859 static inline int spin_needbreak(spinlock_t *lock)
2860 {
2861 #ifdef CONFIG_PREEMPT
2862 	return spin_is_contended(lock);
2863 #else
2864 	return 0;
2865 #endif
2866 }
2867 
2868 /*
2869  * Idle thread specific functions to determine the need_resched
2870  * polling state.
2871  */
2872 #ifdef TIF_POLLING_NRFLAG
2873 static inline int tsk_is_polling(struct task_struct *p)
2874 {
2875 	return test_tsk_thread_flag(p, TIF_POLLING_NRFLAG);
2876 }
2877 
2878 static inline void __current_set_polling(void)
2879 {
2880 	set_thread_flag(TIF_POLLING_NRFLAG);
2881 }
2882 
2883 static inline bool __must_check current_set_polling_and_test(void)
2884 {
2885 	__current_set_polling();
2886 
2887 	/*
2888 	 * Polling state must be visible before we test NEED_RESCHED,
2889 	 * paired by resched_curr()
2890 	 */
2891 	smp_mb__after_atomic();
2892 
2893 	return unlikely(tif_need_resched());
2894 }
2895 
2896 static inline void __current_clr_polling(void)
2897 {
2898 	clear_thread_flag(TIF_POLLING_NRFLAG);
2899 }
2900 
2901 static inline bool __must_check current_clr_polling_and_test(void)
2902 {
2903 	__current_clr_polling();
2904 
2905 	/*
2906 	 * Polling state must be visible before we test NEED_RESCHED,
2907 	 * paired by resched_curr()
2908 	 */
2909 	smp_mb__after_atomic();
2910 
2911 	return unlikely(tif_need_resched());
2912 }
2913 
2914 #else
2915 static inline int tsk_is_polling(struct task_struct *p) { return 0; }
2916 static inline void __current_set_polling(void) { }
2917 static inline void __current_clr_polling(void) { }
2918 
2919 static inline bool __must_check current_set_polling_and_test(void)
2920 {
2921 	return unlikely(tif_need_resched());
2922 }
2923 static inline bool __must_check current_clr_polling_and_test(void)
2924 {
2925 	return unlikely(tif_need_resched());
2926 }
2927 #endif
2928 
2929 static inline void current_clr_polling(void)
2930 {
2931 	__current_clr_polling();
2932 
2933 	/*
2934 	 * Ensure we check TIF_NEED_RESCHED after we clear the polling bit.
2935 	 * Once the bit is cleared, we'll get IPIs with every new
2936 	 * TIF_NEED_RESCHED and the IPI handler, scheduler_ipi(), will also
2937 	 * fold.
2938 	 */
2939 	smp_mb(); /* paired with resched_curr() */
2940 
2941 	preempt_fold_need_resched();
2942 }
2943 
2944 static __always_inline bool need_resched(void)
2945 {
2946 	return unlikely(tif_need_resched());
2947 }
2948 
2949 /*
2950  * Thread group CPU time accounting.
2951  */
2952 void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
2953 void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
2954 
2955 static inline void thread_group_cputime_init(struct signal_struct *sig)
2956 {
2957 	raw_spin_lock_init(&sig->cputimer.lock);
2958 }
2959 
2960 /*
2961  * Reevaluate whether the task has signals pending delivery.
2962  * Wake the task if so.
2963  * This is required every time the blocked sigset_t changes.
2964  * callers must hold sighand->siglock.
2965  */
2966 extern void recalc_sigpending_and_wake(struct task_struct *t);
2967 extern void recalc_sigpending(void);
2968 
2969 extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
2970 
2971 static inline void signal_wake_up(struct task_struct *t, bool resume)
2972 {
2973 	signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0);
2974 }
2975 static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
2976 {
2977 	signal_wake_up_state(t, resume ? __TASK_TRACED : 0);
2978 }
2979 
2980 /*
2981  * Wrappers for p->thread_info->cpu access. No-op on UP.
2982  */
2983 #ifdef CONFIG_SMP
2984 
2985 static inline unsigned int task_cpu(const struct task_struct *p)
2986 {
2987 	return task_thread_info(p)->cpu;
2988 }
2989 
2990 static inline int task_node(const struct task_struct *p)
2991 {
2992 	return cpu_to_node(task_cpu(p));
2993 }
2994 
2995 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2996 
2997 #else
2998 
2999 static inline unsigned int task_cpu(const struct task_struct *p)
3000 {
3001 	return 0;
3002 }
3003 
3004 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
3005 {
3006 }
3007 
3008 #endif /* CONFIG_SMP */
3009 
3010 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
3011 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
3012 
3013 #ifdef CONFIG_CGROUP_SCHED
3014 extern struct task_group root_task_group;
3015 #endif /* CONFIG_CGROUP_SCHED */
3016 
3017 extern int task_can_switch_user(struct user_struct *up,
3018 					struct task_struct *tsk);
3019 
3020 #ifdef CONFIG_TASK_XACCT
3021 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
3022 {
3023 	tsk->ioac.rchar += amt;
3024 }
3025 
3026 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
3027 {
3028 	tsk->ioac.wchar += amt;
3029 }
3030 
3031 static inline void inc_syscr(struct task_struct *tsk)
3032 {
3033 	tsk->ioac.syscr++;
3034 }
3035 
3036 static inline void inc_syscw(struct task_struct *tsk)
3037 {
3038 	tsk->ioac.syscw++;
3039 }
3040 #else
3041 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
3042 {
3043 }
3044 
3045 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
3046 {
3047 }
3048 
3049 static inline void inc_syscr(struct task_struct *tsk)
3050 {
3051 }
3052 
3053 static inline void inc_syscw(struct task_struct *tsk)
3054 {
3055 }
3056 #endif
3057 
3058 #ifndef TASK_SIZE_OF
3059 #define TASK_SIZE_OF(tsk)	TASK_SIZE
3060 #endif
3061 
3062 #ifdef CONFIG_MEMCG
3063 extern void mm_update_next_owner(struct mm_struct *mm);
3064 #else
3065 static inline void mm_update_next_owner(struct mm_struct *mm)
3066 {
3067 }
3068 #endif /* CONFIG_MEMCG */
3069 
3070 static inline unsigned long task_rlimit(const struct task_struct *tsk,
3071 		unsigned int limit)
3072 {
3073 	return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_cur);
3074 }
3075 
3076 static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
3077 		unsigned int limit)
3078 {
3079 	return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_max);
3080 }
3081 
3082 static inline unsigned long rlimit(unsigned int limit)
3083 {
3084 	return task_rlimit(current, limit);
3085 }
3086 
3087 static inline unsigned long rlimit_max(unsigned int limit)
3088 {
3089 	return task_rlimit_max(current, limit);
3090 }
3091 
3092 #endif
3093