xref: /linux-6.15/include/linux/sched.h (revision 261a9af6)
1 #ifndef _LINUX_SCHED_H
2 #define _LINUX_SCHED_H
3 
4 /*
5  * cloning flags:
6  */
7 #define CSIGNAL		0x000000ff	/* signal mask to be sent at exit */
8 #define CLONE_VM	0x00000100	/* set if VM shared between processes */
9 #define CLONE_FS	0x00000200	/* set if fs info shared between processes */
10 #define CLONE_FILES	0x00000400	/* set if open files shared between processes */
11 #define CLONE_SIGHAND	0x00000800	/* set if signal handlers and blocked signals shared */
12 #define CLONE_PTRACE	0x00002000	/* set if we want to let tracing continue on the child too */
13 #define CLONE_VFORK	0x00004000	/* set if the parent wants the child to wake it up on mm_release */
14 #define CLONE_PARENT	0x00008000	/* set if we want to have the same parent as the cloner */
15 #define CLONE_THREAD	0x00010000	/* Same thread group? */
16 #define CLONE_NEWNS	0x00020000	/* New namespace group? */
17 #define CLONE_SYSVSEM	0x00040000	/* share system V SEM_UNDO semantics */
18 #define CLONE_SETTLS	0x00080000	/* create a new TLS for the child */
19 #define CLONE_PARENT_SETTID	0x00100000	/* set the TID in the parent */
20 #define CLONE_CHILD_CLEARTID	0x00200000	/* clear the TID in the child */
21 #define CLONE_DETACHED		0x00400000	/* Unused, ignored */
22 #define CLONE_UNTRACED		0x00800000	/* set if the tracing process can't force CLONE_PTRACE on this clone */
23 #define CLONE_CHILD_SETTID	0x01000000	/* set the TID in the child */
24 /* 0x02000000 was previously the unused CLONE_STOPPED (Start in stopped state)
25    and is now available for re-use. */
26 #define CLONE_NEWUTS		0x04000000	/* New utsname group? */
27 #define CLONE_NEWIPC		0x08000000	/* New ipcs */
28 #define CLONE_NEWUSER		0x10000000	/* New user namespace */
29 #define CLONE_NEWPID		0x20000000	/* New pid namespace */
30 #define CLONE_NEWNET		0x40000000	/* New network namespace */
31 #define CLONE_IO		0x80000000	/* Clone io context */
32 
33 /*
34  * Scheduling policies
35  */
36 #define SCHED_NORMAL		0
37 #define SCHED_FIFO		1
38 #define SCHED_RR		2
39 #define SCHED_BATCH		3
40 /* SCHED_ISO: reserved but not implemented yet */
41 #define SCHED_IDLE		5
42 /* Can be ORed in to make sure the process is reverted back to SCHED_NORMAL on fork */
43 #define SCHED_RESET_ON_FORK     0x40000000
44 
45 #ifdef __KERNEL__
46 
47 struct sched_param {
48 	int sched_priority;
49 };
50 
51 #include <asm/param.h>	/* for HZ */
52 
53 #include <linux/capability.h>
54 #include <linux/threads.h>
55 #include <linux/kernel.h>
56 #include <linux/types.h>
57 #include <linux/timex.h>
58 #include <linux/jiffies.h>
59 #include <linux/rbtree.h>
60 #include <linux/thread_info.h>
61 #include <linux/cpumask.h>
62 #include <linux/errno.h>
63 #include <linux/nodemask.h>
64 #include <linux/mm_types.h>
65 
66 #include <asm/system.h>
67 #include <asm/page.h>
68 #include <asm/ptrace.h>
69 #include <asm/cputime.h>
70 
71 #include <linux/smp.h>
72 #include <linux/sem.h>
73 #include <linux/signal.h>
74 #include <linux/compiler.h>
75 #include <linux/completion.h>
76 #include <linux/pid.h>
77 #include <linux/percpu.h>
78 #include <linux/topology.h>
79 #include <linux/proportions.h>
80 #include <linux/seccomp.h>
81 #include <linux/rcupdate.h>
82 #include <linux/rculist.h>
83 #include <linux/rtmutex.h>
84 
85 #include <linux/time.h>
86 #include <linux/param.h>
87 #include <linux/resource.h>
88 #include <linux/timer.h>
89 #include <linux/hrtimer.h>
90 #include <linux/task_io_accounting.h>
91 #include <linux/latencytop.h>
92 #include <linux/cred.h>
93 
94 #include <asm/processor.h>
95 
96 struct exec_domain;
97 struct futex_pi_state;
98 struct robust_list_head;
99 struct bio_list;
100 struct fs_struct;
101 struct perf_event_context;
102 struct blk_plug;
103 
104 /*
105  * List of flags we want to share for kernel threads,
106  * if only because they are not used by them anyway.
107  */
108 #define CLONE_KERNEL	(CLONE_FS | CLONE_FILES | CLONE_SIGHAND)
109 
110 /*
111  * These are the constant used to fake the fixed-point load-average
112  * counting. Some notes:
113  *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
114  *    a load-average precision of 10 bits integer + 11 bits fractional
115  *  - if you want to count load-averages more often, you need more
116  *    precision, or rounding will get you. With 2-second counting freq,
117  *    the EXP_n values would be 1981, 2034 and 2043 if still using only
118  *    11 bit fractions.
119  */
120 extern unsigned long avenrun[];		/* Load averages */
121 extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
122 
123 #define FSHIFT		11		/* nr of bits of precision */
124 #define FIXED_1		(1<<FSHIFT)	/* 1.0 as fixed-point */
125 #define LOAD_FREQ	(5*HZ+1)	/* 5 sec intervals */
126 #define EXP_1		1884		/* 1/exp(5sec/1min) as fixed-point */
127 #define EXP_5		2014		/* 1/exp(5sec/5min) */
128 #define EXP_15		2037		/* 1/exp(5sec/15min) */
129 
130 #define CALC_LOAD(load,exp,n) \
131 	load *= exp; \
132 	load += n*(FIXED_1-exp); \
133 	load >>= FSHIFT;
134 
135 extern unsigned long total_forks;
136 extern int nr_threads;
137 DECLARE_PER_CPU(unsigned long, process_counts);
138 extern int nr_processes(void);
139 extern unsigned long nr_running(void);
140 extern unsigned long nr_uninterruptible(void);
141 extern unsigned long nr_iowait(void);
142 extern unsigned long nr_iowait_cpu(int cpu);
143 extern unsigned long this_cpu_load(void);
144 
145 
146 extern void calc_global_load(unsigned long ticks);
147 
148 extern unsigned long get_parent_ip(unsigned long addr);
149 
150 struct seq_file;
151 struct cfs_rq;
152 struct task_group;
153 #ifdef CONFIG_SCHED_DEBUG
154 extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
155 extern void proc_sched_set_task(struct task_struct *p);
156 extern void
157 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
158 #else
159 static inline void
160 proc_sched_show_task(struct task_struct *p, struct seq_file *m)
161 {
162 }
163 static inline void proc_sched_set_task(struct task_struct *p)
164 {
165 }
166 static inline void
167 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
168 {
169 }
170 #endif
171 
172 /*
173  * Task state bitmask. NOTE! These bits are also
174  * encoded in fs/proc/array.c: get_task_state().
175  *
176  * We have two separate sets of flags: task->state
177  * is about runnability, while task->exit_state are
178  * about the task exiting. Confusing, but this way
179  * modifying one set can't modify the other one by
180  * mistake.
181  */
182 #define TASK_RUNNING		0
183 #define TASK_INTERRUPTIBLE	1
184 #define TASK_UNINTERRUPTIBLE	2
185 #define __TASK_STOPPED		4
186 #define __TASK_TRACED		8
187 /* in tsk->exit_state */
188 #define EXIT_ZOMBIE		16
189 #define EXIT_DEAD		32
190 /* in tsk->state again */
191 #define TASK_DEAD		64
192 #define TASK_WAKEKILL		128
193 #define TASK_WAKING		256
194 #define TASK_STATE_MAX		512
195 
196 #define TASK_STATE_TO_CHAR_STR "RSDTtZXxKW"
197 
198 extern char ___assert_task_state[1 - 2*!!(
199 		sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
200 
201 /* Convenience macros for the sake of set_task_state */
202 #define TASK_KILLABLE		(TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
203 #define TASK_STOPPED		(TASK_WAKEKILL | __TASK_STOPPED)
204 #define TASK_TRACED		(TASK_WAKEKILL | __TASK_TRACED)
205 
206 /* Convenience macros for the sake of wake_up */
207 #define TASK_NORMAL		(TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
208 #define TASK_ALL		(TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
209 
210 /* get_task_state() */
211 #define TASK_REPORT		(TASK_RUNNING | TASK_INTERRUPTIBLE | \
212 				 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
213 				 __TASK_TRACED)
214 
215 #define task_is_traced(task)	((task->state & __TASK_TRACED) != 0)
216 #define task_is_stopped(task)	((task->state & __TASK_STOPPED) != 0)
217 #define task_is_dead(task)	((task)->exit_state != 0)
218 #define task_is_stopped_or_traced(task)	\
219 			((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
220 #define task_contributes_to_load(task)	\
221 				((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
222 				 (task->flags & PF_FREEZING) == 0)
223 
224 #define __set_task_state(tsk, state_value)		\
225 	do { (tsk)->state = (state_value); } while (0)
226 #define set_task_state(tsk, state_value)		\
227 	set_mb((tsk)->state, (state_value))
228 
229 /*
230  * set_current_state() includes a barrier so that the write of current->state
231  * is correctly serialised wrt the caller's subsequent test of whether to
232  * actually sleep:
233  *
234  *	set_current_state(TASK_UNINTERRUPTIBLE);
235  *	if (do_i_need_to_sleep())
236  *		schedule();
237  *
238  * If the caller does not need such serialisation then use __set_current_state()
239  */
240 #define __set_current_state(state_value)			\
241 	do { current->state = (state_value); } while (0)
242 #define set_current_state(state_value)		\
243 	set_mb(current->state, (state_value))
244 
245 /* Task command name length */
246 #define TASK_COMM_LEN 16
247 
248 #include <linux/spinlock.h>
249 
250 /*
251  * This serializes "schedule()" and also protects
252  * the run-queue from deletions/modifications (but
253  * _adding_ to the beginning of the run-queue has
254  * a separate lock).
255  */
256 extern rwlock_t tasklist_lock;
257 extern spinlock_t mmlist_lock;
258 
259 struct task_struct;
260 
261 #ifdef CONFIG_PROVE_RCU
262 extern int lockdep_tasklist_lock_is_held(void);
263 #endif /* #ifdef CONFIG_PROVE_RCU */
264 
265 extern void sched_init(void);
266 extern void sched_init_smp(void);
267 extern asmlinkage void schedule_tail(struct task_struct *prev);
268 extern void init_idle(struct task_struct *idle, int cpu);
269 extern void init_idle_bootup_task(struct task_struct *idle);
270 
271 extern int runqueue_is_locked(int cpu);
272 
273 extern cpumask_var_t nohz_cpu_mask;
274 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ)
275 extern void select_nohz_load_balancer(int stop_tick);
276 extern int get_nohz_timer_target(void);
277 #else
278 static inline void select_nohz_load_balancer(int stop_tick) { }
279 #endif
280 
281 /*
282  * Only dump TASK_* tasks. (0 for all tasks)
283  */
284 extern void show_state_filter(unsigned long state_filter);
285 
286 static inline void show_state(void)
287 {
288 	show_state_filter(0);
289 }
290 
291 extern void show_regs(struct pt_regs *);
292 
293 /*
294  * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
295  * task), SP is the stack pointer of the first frame that should be shown in the back
296  * trace (or NULL if the entire call-chain of the task should be shown).
297  */
298 extern void show_stack(struct task_struct *task, unsigned long *sp);
299 
300 void io_schedule(void);
301 long io_schedule_timeout(long timeout);
302 
303 extern void cpu_init (void);
304 extern void trap_init(void);
305 extern void update_process_times(int user);
306 extern void scheduler_tick(void);
307 
308 extern void sched_show_task(struct task_struct *p);
309 
310 #ifdef CONFIG_LOCKUP_DETECTOR
311 extern void touch_softlockup_watchdog(void);
312 extern void touch_softlockup_watchdog_sync(void);
313 extern void touch_all_softlockup_watchdogs(void);
314 extern int proc_dowatchdog_thresh(struct ctl_table *table, int write,
315 				  void __user *buffer,
316 				  size_t *lenp, loff_t *ppos);
317 extern unsigned int  softlockup_panic;
318 void lockup_detector_init(void);
319 #else
320 static inline void touch_softlockup_watchdog(void)
321 {
322 }
323 static inline void touch_softlockup_watchdog_sync(void)
324 {
325 }
326 static inline void touch_all_softlockup_watchdogs(void)
327 {
328 }
329 static inline void lockup_detector_init(void)
330 {
331 }
332 #endif
333 
334 #ifdef CONFIG_DETECT_HUNG_TASK
335 extern unsigned int  sysctl_hung_task_panic;
336 extern unsigned long sysctl_hung_task_check_count;
337 extern unsigned long sysctl_hung_task_timeout_secs;
338 extern unsigned long sysctl_hung_task_warnings;
339 extern int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
340 					 void __user *buffer,
341 					 size_t *lenp, loff_t *ppos);
342 #else
343 /* Avoid need for ifdefs elsewhere in the code */
344 enum { sysctl_hung_task_timeout_secs = 0 };
345 #endif
346 
347 /* Attach to any functions which should be ignored in wchan output. */
348 #define __sched		__attribute__((__section__(".sched.text")))
349 
350 /* Linker adds these: start and end of __sched functions */
351 extern char __sched_text_start[], __sched_text_end[];
352 
353 /* Is this address in the __sched functions? */
354 extern int in_sched_functions(unsigned long addr);
355 
356 #define	MAX_SCHEDULE_TIMEOUT	LONG_MAX
357 extern signed long schedule_timeout(signed long timeout);
358 extern signed long schedule_timeout_interruptible(signed long timeout);
359 extern signed long schedule_timeout_killable(signed long timeout);
360 extern signed long schedule_timeout_uninterruptible(signed long timeout);
361 asmlinkage void schedule(void);
362 extern int mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner);
363 
364 struct nsproxy;
365 struct user_namespace;
366 
367 /*
368  * Default maximum number of active map areas, this limits the number of vmas
369  * per mm struct. Users can overwrite this number by sysctl but there is a
370  * problem.
371  *
372  * When a program's coredump is generated as ELF format, a section is created
373  * per a vma. In ELF, the number of sections is represented in unsigned short.
374  * This means the number of sections should be smaller than 65535 at coredump.
375  * Because the kernel adds some informative sections to a image of program at
376  * generating coredump, we need some margin. The number of extra sections is
377  * 1-3 now and depends on arch. We use "5" as safe margin, here.
378  */
379 #define MAPCOUNT_ELF_CORE_MARGIN	(5)
380 #define DEFAULT_MAX_MAP_COUNT	(USHRT_MAX - MAPCOUNT_ELF_CORE_MARGIN)
381 
382 extern int sysctl_max_map_count;
383 
384 #include <linux/aio.h>
385 
386 #ifdef CONFIG_MMU
387 extern void arch_pick_mmap_layout(struct mm_struct *mm);
388 extern unsigned long
389 arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
390 		       unsigned long, unsigned long);
391 extern unsigned long
392 arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
393 			  unsigned long len, unsigned long pgoff,
394 			  unsigned long flags);
395 extern void arch_unmap_area(struct mm_struct *, unsigned long);
396 extern void arch_unmap_area_topdown(struct mm_struct *, unsigned long);
397 #else
398 static inline void arch_pick_mmap_layout(struct mm_struct *mm) {}
399 #endif
400 
401 
402 extern void set_dumpable(struct mm_struct *mm, int value);
403 extern int get_dumpable(struct mm_struct *mm);
404 
405 /* mm flags */
406 /* dumpable bits */
407 #define MMF_DUMPABLE      0  /* core dump is permitted */
408 #define MMF_DUMP_SECURELY 1  /* core file is readable only by root */
409 
410 #define MMF_DUMPABLE_BITS 2
411 #define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
412 
413 /* coredump filter bits */
414 #define MMF_DUMP_ANON_PRIVATE	2
415 #define MMF_DUMP_ANON_SHARED	3
416 #define MMF_DUMP_MAPPED_PRIVATE	4
417 #define MMF_DUMP_MAPPED_SHARED	5
418 #define MMF_DUMP_ELF_HEADERS	6
419 #define MMF_DUMP_HUGETLB_PRIVATE 7
420 #define MMF_DUMP_HUGETLB_SHARED  8
421 
422 #define MMF_DUMP_FILTER_SHIFT	MMF_DUMPABLE_BITS
423 #define MMF_DUMP_FILTER_BITS	7
424 #define MMF_DUMP_FILTER_MASK \
425 	(((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
426 #define MMF_DUMP_FILTER_DEFAULT \
427 	((1 << MMF_DUMP_ANON_PRIVATE) |	(1 << MMF_DUMP_ANON_SHARED) |\
428 	 (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
429 
430 #ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
431 # define MMF_DUMP_MASK_DEFAULT_ELF	(1 << MMF_DUMP_ELF_HEADERS)
432 #else
433 # define MMF_DUMP_MASK_DEFAULT_ELF	0
434 #endif
435 					/* leave room for more dump flags */
436 #define MMF_VM_MERGEABLE	16	/* KSM may merge identical pages */
437 #define MMF_VM_HUGEPAGE		17	/* set when VM_HUGEPAGE is set on vma */
438 
439 #define MMF_INIT_MASK		(MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
440 
441 struct sighand_struct {
442 	atomic_t		count;
443 	struct k_sigaction	action[_NSIG];
444 	spinlock_t		siglock;
445 	wait_queue_head_t	signalfd_wqh;
446 };
447 
448 struct pacct_struct {
449 	int			ac_flag;
450 	long			ac_exitcode;
451 	unsigned long		ac_mem;
452 	cputime_t		ac_utime, ac_stime;
453 	unsigned long		ac_minflt, ac_majflt;
454 };
455 
456 struct cpu_itimer {
457 	cputime_t expires;
458 	cputime_t incr;
459 	u32 error;
460 	u32 incr_error;
461 };
462 
463 /**
464  * struct task_cputime - collected CPU time counts
465  * @utime:		time spent in user mode, in &cputime_t units
466  * @stime:		time spent in kernel mode, in &cputime_t units
467  * @sum_exec_runtime:	total time spent on the CPU, in nanoseconds
468  *
469  * This structure groups together three kinds of CPU time that are
470  * tracked for threads and thread groups.  Most things considering
471  * CPU time want to group these counts together and treat all three
472  * of them in parallel.
473  */
474 struct task_cputime {
475 	cputime_t utime;
476 	cputime_t stime;
477 	unsigned long long sum_exec_runtime;
478 };
479 /* Alternate field names when used to cache expirations. */
480 #define prof_exp	stime
481 #define virt_exp	utime
482 #define sched_exp	sum_exec_runtime
483 
484 #define INIT_CPUTIME	\
485 	(struct task_cputime) {					\
486 		.utime = cputime_zero,				\
487 		.stime = cputime_zero,				\
488 		.sum_exec_runtime = 0,				\
489 	}
490 
491 /*
492  * Disable preemption until the scheduler is running.
493  * Reset by start_kernel()->sched_init()->init_idle().
494  *
495  * We include PREEMPT_ACTIVE to avoid cond_resched() from working
496  * before the scheduler is active -- see should_resched().
497  */
498 #define INIT_PREEMPT_COUNT	(1 + PREEMPT_ACTIVE)
499 
500 /**
501  * struct thread_group_cputimer - thread group interval timer counts
502  * @cputime:		thread group interval timers.
503  * @running:		non-zero when there are timers running and
504  * 			@cputime receives updates.
505  * @lock:		lock for fields in this struct.
506  *
507  * This structure contains the version of task_cputime, above, that is
508  * used for thread group CPU timer calculations.
509  */
510 struct thread_group_cputimer {
511 	struct task_cputime cputime;
512 	int running;
513 	spinlock_t lock;
514 };
515 
516 #include <linux/rwsem.h>
517 struct autogroup;
518 
519 /*
520  * NOTE! "signal_struct" does not have its own
521  * locking, because a shared signal_struct always
522  * implies a shared sighand_struct, so locking
523  * sighand_struct is always a proper superset of
524  * the locking of signal_struct.
525  */
526 struct signal_struct {
527 	atomic_t		sigcnt;
528 	atomic_t		live;
529 	int			nr_threads;
530 
531 	wait_queue_head_t	wait_chldexit;	/* for wait4() */
532 
533 	/* current thread group signal load-balancing target: */
534 	struct task_struct	*curr_target;
535 
536 	/* shared signal handling: */
537 	struct sigpending	shared_pending;
538 
539 	/* thread group exit support */
540 	int			group_exit_code;
541 	/* overloaded:
542 	 * - notify group_exit_task when ->count is equal to notify_count
543 	 * - everyone except group_exit_task is stopped during signal delivery
544 	 *   of fatal signals, group_exit_task processes the signal.
545 	 */
546 	int			notify_count;
547 	struct task_struct	*group_exit_task;
548 
549 	/* thread group stop support, overloads group_exit_code too */
550 	int			group_stop_count;
551 	unsigned int		flags; /* see SIGNAL_* flags below */
552 
553 	/* POSIX.1b Interval Timers */
554 	struct list_head posix_timers;
555 
556 	/* ITIMER_REAL timer for the process */
557 	struct hrtimer real_timer;
558 	struct pid *leader_pid;
559 	ktime_t it_real_incr;
560 
561 	/*
562 	 * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
563 	 * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
564 	 * values are defined to 0 and 1 respectively
565 	 */
566 	struct cpu_itimer it[2];
567 
568 	/*
569 	 * Thread group totals for process CPU timers.
570 	 * See thread_group_cputimer(), et al, for details.
571 	 */
572 	struct thread_group_cputimer cputimer;
573 
574 	/* Earliest-expiration cache. */
575 	struct task_cputime cputime_expires;
576 
577 	struct list_head cpu_timers[3];
578 
579 	struct pid *tty_old_pgrp;
580 
581 	/* boolean value for session group leader */
582 	int leader;
583 
584 	struct tty_struct *tty; /* NULL if no tty */
585 
586 #ifdef CONFIG_SCHED_AUTOGROUP
587 	struct autogroup *autogroup;
588 #endif
589 	/*
590 	 * Cumulative resource counters for dead threads in the group,
591 	 * and for reaped dead child processes forked by this group.
592 	 * Live threads maintain their own counters and add to these
593 	 * in __exit_signal, except for the group leader.
594 	 */
595 	cputime_t utime, stime, cutime, cstime;
596 	cputime_t gtime;
597 	cputime_t cgtime;
598 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
599 	cputime_t prev_utime, prev_stime;
600 #endif
601 	unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
602 	unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
603 	unsigned long inblock, oublock, cinblock, coublock;
604 	unsigned long maxrss, cmaxrss;
605 	struct task_io_accounting ioac;
606 
607 	/*
608 	 * Cumulative ns of schedule CPU time fo dead threads in the
609 	 * group, not including a zombie group leader, (This only differs
610 	 * from jiffies_to_ns(utime + stime) if sched_clock uses something
611 	 * other than jiffies.)
612 	 */
613 	unsigned long long sum_sched_runtime;
614 
615 	/*
616 	 * We don't bother to synchronize most readers of this at all,
617 	 * because there is no reader checking a limit that actually needs
618 	 * to get both rlim_cur and rlim_max atomically, and either one
619 	 * alone is a single word that can safely be read normally.
620 	 * getrlimit/setrlimit use task_lock(current->group_leader) to
621 	 * protect this instead of the siglock, because they really
622 	 * have no need to disable irqs.
623 	 */
624 	struct rlimit rlim[RLIM_NLIMITS];
625 
626 #ifdef CONFIG_BSD_PROCESS_ACCT
627 	struct pacct_struct pacct;	/* per-process accounting information */
628 #endif
629 #ifdef CONFIG_TASKSTATS
630 	struct taskstats *stats;
631 #endif
632 #ifdef CONFIG_AUDIT
633 	unsigned audit_tty;
634 	struct tty_audit_buf *tty_audit_buf;
635 #endif
636 #ifdef CONFIG_CGROUPS
637 	/*
638 	 * The threadgroup_fork_lock prevents threads from forking with
639 	 * CLONE_THREAD while held for writing. Use this for fork-sensitive
640 	 * threadgroup-wide operations. It's taken for reading in fork.c in
641 	 * copy_process().
642 	 * Currently only needed write-side by cgroups.
643 	 */
644 	struct rw_semaphore threadgroup_fork_lock;
645 #endif
646 
647 	int oom_adj;		/* OOM kill score adjustment (bit shift) */
648 	int oom_score_adj;	/* OOM kill score adjustment */
649 	int oom_score_adj_min;	/* OOM kill score adjustment minimum value.
650 				 * Only settable by CAP_SYS_RESOURCE. */
651 
652 	struct mutex cred_guard_mutex;	/* guard against foreign influences on
653 					 * credential calculations
654 					 * (notably. ptrace) */
655 };
656 
657 /* Context switch must be unlocked if interrupts are to be enabled */
658 #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
659 # define __ARCH_WANT_UNLOCKED_CTXSW
660 #endif
661 
662 /*
663  * Bits in flags field of signal_struct.
664  */
665 #define SIGNAL_STOP_STOPPED	0x00000001 /* job control stop in effect */
666 #define SIGNAL_STOP_CONTINUED	0x00000002 /* SIGCONT since WCONTINUED reap */
667 #define SIGNAL_GROUP_EXIT	0x00000004 /* group exit in progress */
668 /*
669  * Pending notifications to parent.
670  */
671 #define SIGNAL_CLD_STOPPED	0x00000010
672 #define SIGNAL_CLD_CONTINUED	0x00000020
673 #define SIGNAL_CLD_MASK		(SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
674 
675 #define SIGNAL_UNKILLABLE	0x00000040 /* for init: ignore fatal signals */
676 
677 /* If true, all threads except ->group_exit_task have pending SIGKILL */
678 static inline int signal_group_exit(const struct signal_struct *sig)
679 {
680 	return	(sig->flags & SIGNAL_GROUP_EXIT) ||
681 		(sig->group_exit_task != NULL);
682 }
683 
684 /*
685  * Some day this will be a full-fledged user tracking system..
686  */
687 struct user_struct {
688 	atomic_t __count;	/* reference count */
689 	atomic_t processes;	/* How many processes does this user have? */
690 	atomic_t files;		/* How many open files does this user have? */
691 	atomic_t sigpending;	/* How many pending signals does this user have? */
692 #ifdef CONFIG_INOTIFY_USER
693 	atomic_t inotify_watches; /* How many inotify watches does this user have? */
694 	atomic_t inotify_devs;	/* How many inotify devs does this user have opened? */
695 #endif
696 #ifdef CONFIG_FANOTIFY
697 	atomic_t fanotify_listeners;
698 #endif
699 #ifdef CONFIG_EPOLL
700 	atomic_long_t epoll_watches; /* The number of file descriptors currently watched */
701 #endif
702 #ifdef CONFIG_POSIX_MQUEUE
703 	/* protected by mq_lock	*/
704 	unsigned long mq_bytes;	/* How many bytes can be allocated to mqueue? */
705 #endif
706 	unsigned long locked_shm; /* How many pages of mlocked shm ? */
707 
708 #ifdef CONFIG_KEYS
709 	struct key *uid_keyring;	/* UID specific keyring */
710 	struct key *session_keyring;	/* UID's default session keyring */
711 #endif
712 
713 	/* Hash table maintenance information */
714 	struct hlist_node uidhash_node;
715 	uid_t uid;
716 	struct user_namespace *user_ns;
717 
718 #ifdef CONFIG_PERF_EVENTS
719 	atomic_long_t locked_vm;
720 #endif
721 };
722 
723 extern int uids_sysfs_init(void);
724 
725 extern struct user_struct *find_user(uid_t);
726 
727 extern struct user_struct root_user;
728 #define INIT_USER (&root_user)
729 
730 
731 struct backing_dev_info;
732 struct reclaim_state;
733 
734 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
735 struct sched_info {
736 	/* cumulative counters */
737 	unsigned long pcount;	      /* # of times run on this cpu */
738 	unsigned long long run_delay; /* time spent waiting on a runqueue */
739 
740 	/* timestamps */
741 	unsigned long long last_arrival,/* when we last ran on a cpu */
742 			   last_queued;	/* when we were last queued to run */
743 };
744 #endif /* defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) */
745 
746 #ifdef CONFIG_TASK_DELAY_ACCT
747 struct task_delay_info {
748 	spinlock_t	lock;
749 	unsigned int	flags;	/* Private per-task flags */
750 
751 	/* For each stat XXX, add following, aligned appropriately
752 	 *
753 	 * struct timespec XXX_start, XXX_end;
754 	 * u64 XXX_delay;
755 	 * u32 XXX_count;
756 	 *
757 	 * Atomicity of updates to XXX_delay, XXX_count protected by
758 	 * single lock above (split into XXX_lock if contention is an issue).
759 	 */
760 
761 	/*
762 	 * XXX_count is incremented on every XXX operation, the delay
763 	 * associated with the operation is added to XXX_delay.
764 	 * XXX_delay contains the accumulated delay time in nanoseconds.
765 	 */
766 	struct timespec blkio_start, blkio_end;	/* Shared by blkio, swapin */
767 	u64 blkio_delay;	/* wait for sync block io completion */
768 	u64 swapin_delay;	/* wait for swapin block io completion */
769 	u32 blkio_count;	/* total count of the number of sync block */
770 				/* io operations performed */
771 	u32 swapin_count;	/* total count of the number of swapin block */
772 				/* io operations performed */
773 
774 	struct timespec freepages_start, freepages_end;
775 	u64 freepages_delay;	/* wait for memory reclaim */
776 	u32 freepages_count;	/* total count of memory reclaim */
777 };
778 #endif	/* CONFIG_TASK_DELAY_ACCT */
779 
780 static inline int sched_info_on(void)
781 {
782 #ifdef CONFIG_SCHEDSTATS
783 	return 1;
784 #elif defined(CONFIG_TASK_DELAY_ACCT)
785 	extern int delayacct_on;
786 	return delayacct_on;
787 #else
788 	return 0;
789 #endif
790 }
791 
792 enum cpu_idle_type {
793 	CPU_IDLE,
794 	CPU_NOT_IDLE,
795 	CPU_NEWLY_IDLE,
796 	CPU_MAX_IDLE_TYPES
797 };
798 
799 /*
800  * Increase resolution of nice-level calculations for 64-bit architectures.
801  * The extra resolution improves shares distribution and load balancing of
802  * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup
803  * hierarchies, especially on larger systems. This is not a user-visible change
804  * and does not change the user-interface for setting shares/weights.
805  *
806  * We increase resolution only if we have enough bits to allow this increased
807  * resolution (i.e. BITS_PER_LONG > 32). The costs for increasing resolution
808  * when BITS_PER_LONG <= 32 are pretty high and the returns do not justify the
809  * increased costs.
810  */
811 #if BITS_PER_LONG > 32
812 # define SCHED_LOAD_RESOLUTION	10
813 # define scale_load(w)		((w) << SCHED_LOAD_RESOLUTION)
814 # define scale_load_down(w)	((w) >> SCHED_LOAD_RESOLUTION)
815 #else
816 # define SCHED_LOAD_RESOLUTION	0
817 # define scale_load(w)		(w)
818 # define scale_load_down(w)	(w)
819 #endif
820 
821 #define SCHED_LOAD_SHIFT	(10 + SCHED_LOAD_RESOLUTION)
822 #define SCHED_LOAD_SCALE	(1L << SCHED_LOAD_SHIFT)
823 
824 /*
825  * Increase resolution of cpu_power calculations
826  */
827 #define SCHED_POWER_SHIFT	10
828 #define SCHED_POWER_SCALE	(1L << SCHED_POWER_SHIFT)
829 
830 /*
831  * sched-domains (multiprocessor balancing) declarations:
832  */
833 #ifdef CONFIG_SMP
834 #define SD_LOAD_BALANCE		0x0001	/* Do load balancing on this domain. */
835 #define SD_BALANCE_NEWIDLE	0x0002	/* Balance when about to become idle */
836 #define SD_BALANCE_EXEC		0x0004	/* Balance on exec */
837 #define SD_BALANCE_FORK		0x0008	/* Balance on fork, clone */
838 #define SD_BALANCE_WAKE		0x0010  /* Balance on wakeup */
839 #define SD_WAKE_AFFINE		0x0020	/* Wake task to waking CPU */
840 #define SD_PREFER_LOCAL		0x0040  /* Prefer to keep tasks local to this domain */
841 #define SD_SHARE_CPUPOWER	0x0080	/* Domain members share cpu power */
842 #define SD_POWERSAVINGS_BALANCE	0x0100	/* Balance for power savings */
843 #define SD_SHARE_PKG_RESOURCES	0x0200	/* Domain members share cpu pkg resources */
844 #define SD_SERIALIZE		0x0400	/* Only a single load balancing instance */
845 #define SD_ASYM_PACKING		0x0800  /* Place busy groups earlier in the domain */
846 #define SD_PREFER_SIBLING	0x1000	/* Prefer to place tasks in a sibling domain */
847 
848 enum powersavings_balance_level {
849 	POWERSAVINGS_BALANCE_NONE = 0,  /* No power saving load balance */
850 	POWERSAVINGS_BALANCE_BASIC,	/* Fill one thread/core/package
851 					 * first for long running threads
852 					 */
853 	POWERSAVINGS_BALANCE_WAKEUP,	/* Also bias task wakeups to semi-idle
854 					 * cpu package for power savings
855 					 */
856 	MAX_POWERSAVINGS_BALANCE_LEVELS
857 };
858 
859 extern int sched_mc_power_savings, sched_smt_power_savings;
860 
861 static inline int sd_balance_for_mc_power(void)
862 {
863 	if (sched_smt_power_savings)
864 		return SD_POWERSAVINGS_BALANCE;
865 
866 	if (!sched_mc_power_savings)
867 		return SD_PREFER_SIBLING;
868 
869 	return 0;
870 }
871 
872 static inline int sd_balance_for_package_power(void)
873 {
874 	if (sched_mc_power_savings | sched_smt_power_savings)
875 		return SD_POWERSAVINGS_BALANCE;
876 
877 	return SD_PREFER_SIBLING;
878 }
879 
880 extern int __weak arch_sd_sibiling_asym_packing(void);
881 
882 /*
883  * Optimise SD flags for power savings:
884  * SD_BALANCE_NEWIDLE helps aggressive task consolidation and power savings.
885  * Keep default SD flags if sched_{smt,mc}_power_saving=0
886  */
887 
888 static inline int sd_power_saving_flags(void)
889 {
890 	if (sched_mc_power_savings | sched_smt_power_savings)
891 		return SD_BALANCE_NEWIDLE;
892 
893 	return 0;
894 }
895 
896 struct sched_group {
897 	struct sched_group *next;	/* Must be a circular list */
898 	atomic_t ref;
899 
900 	/*
901 	 * CPU power of this group, SCHED_LOAD_SCALE being max power for a
902 	 * single CPU.
903 	 */
904 	unsigned int cpu_power, cpu_power_orig;
905 	unsigned int group_weight;
906 
907 	/*
908 	 * The CPUs this group covers.
909 	 *
910 	 * NOTE: this field is variable length. (Allocated dynamically
911 	 * by attaching extra space to the end of the structure,
912 	 * depending on how many CPUs the kernel has booted up with)
913 	 */
914 	unsigned long cpumask[0];
915 };
916 
917 static inline struct cpumask *sched_group_cpus(struct sched_group *sg)
918 {
919 	return to_cpumask(sg->cpumask);
920 }
921 
922 struct sched_domain_attr {
923 	int relax_domain_level;
924 };
925 
926 #define SD_ATTR_INIT	(struct sched_domain_attr) {	\
927 	.relax_domain_level = -1,			\
928 }
929 
930 extern int sched_domain_level_max;
931 
932 struct sched_domain {
933 	/* These fields must be setup */
934 	struct sched_domain *parent;	/* top domain must be null terminated */
935 	struct sched_domain *child;	/* bottom domain must be null terminated */
936 	struct sched_group *groups;	/* the balancing groups of the domain */
937 	unsigned long min_interval;	/* Minimum balance interval ms */
938 	unsigned long max_interval;	/* Maximum balance interval ms */
939 	unsigned int busy_factor;	/* less balancing by factor if busy */
940 	unsigned int imbalance_pct;	/* No balance until over watermark */
941 	unsigned int cache_nice_tries;	/* Leave cache hot tasks for # tries */
942 	unsigned int busy_idx;
943 	unsigned int idle_idx;
944 	unsigned int newidle_idx;
945 	unsigned int wake_idx;
946 	unsigned int forkexec_idx;
947 	unsigned int smt_gain;
948 	int flags;			/* See SD_* */
949 	int level;
950 
951 	/* Runtime fields. */
952 	unsigned long last_balance;	/* init to jiffies. units in jiffies */
953 	unsigned int balance_interval;	/* initialise to 1. units in ms. */
954 	unsigned int nr_balance_failed; /* initialise to 0 */
955 
956 	u64 last_update;
957 
958 #ifdef CONFIG_SCHEDSTATS
959 	/* load_balance() stats */
960 	unsigned int lb_count[CPU_MAX_IDLE_TYPES];
961 	unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
962 	unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
963 	unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
964 	unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
965 	unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
966 	unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
967 	unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
968 
969 	/* Active load balancing */
970 	unsigned int alb_count;
971 	unsigned int alb_failed;
972 	unsigned int alb_pushed;
973 
974 	/* SD_BALANCE_EXEC stats */
975 	unsigned int sbe_count;
976 	unsigned int sbe_balanced;
977 	unsigned int sbe_pushed;
978 
979 	/* SD_BALANCE_FORK stats */
980 	unsigned int sbf_count;
981 	unsigned int sbf_balanced;
982 	unsigned int sbf_pushed;
983 
984 	/* try_to_wake_up() stats */
985 	unsigned int ttwu_wake_remote;
986 	unsigned int ttwu_move_affine;
987 	unsigned int ttwu_move_balance;
988 #endif
989 #ifdef CONFIG_SCHED_DEBUG
990 	char *name;
991 #endif
992 	union {
993 		void *private;		/* used during construction */
994 		struct rcu_head rcu;	/* used during destruction */
995 	};
996 
997 	unsigned int span_weight;
998 	/*
999 	 * Span of all CPUs in this domain.
1000 	 *
1001 	 * NOTE: this field is variable length. (Allocated dynamically
1002 	 * by attaching extra space to the end of the structure,
1003 	 * depending on how many CPUs the kernel has booted up with)
1004 	 */
1005 	unsigned long span[0];
1006 };
1007 
1008 static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
1009 {
1010 	return to_cpumask(sd->span);
1011 }
1012 
1013 extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1014 				    struct sched_domain_attr *dattr_new);
1015 
1016 /* Allocate an array of sched domains, for partition_sched_domains(). */
1017 cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
1018 void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
1019 
1020 /* Test a flag in parent sched domain */
1021 static inline int test_sd_parent(struct sched_domain *sd, int flag)
1022 {
1023 	if (sd->parent && (sd->parent->flags & flag))
1024 		return 1;
1025 
1026 	return 0;
1027 }
1028 
1029 unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu);
1030 unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu);
1031 
1032 #else /* CONFIG_SMP */
1033 
1034 struct sched_domain_attr;
1035 
1036 static inline void
1037 partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1038 			struct sched_domain_attr *dattr_new)
1039 {
1040 }
1041 #endif	/* !CONFIG_SMP */
1042 
1043 
1044 struct io_context;			/* See blkdev.h */
1045 
1046 
1047 #ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
1048 extern void prefetch_stack(struct task_struct *t);
1049 #else
1050 static inline void prefetch_stack(struct task_struct *t) { }
1051 #endif
1052 
1053 struct audit_context;		/* See audit.c */
1054 struct mempolicy;
1055 struct pipe_inode_info;
1056 struct uts_namespace;
1057 
1058 struct rq;
1059 struct sched_domain;
1060 
1061 /*
1062  * wake flags
1063  */
1064 #define WF_SYNC		0x01		/* waker goes to sleep after wakup */
1065 #define WF_FORK		0x02		/* child wakeup after fork */
1066 #define WF_MIGRATED	0x04		/* internal use, task got migrated */
1067 
1068 #define ENQUEUE_WAKEUP		1
1069 #define ENQUEUE_HEAD		2
1070 #ifdef CONFIG_SMP
1071 #define ENQUEUE_WAKING		4	/* sched_class::task_waking was called */
1072 #else
1073 #define ENQUEUE_WAKING		0
1074 #endif
1075 
1076 #define DEQUEUE_SLEEP		1
1077 
1078 struct sched_class {
1079 	const struct sched_class *next;
1080 
1081 	void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags);
1082 	void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags);
1083 	void (*yield_task) (struct rq *rq);
1084 	bool (*yield_to_task) (struct rq *rq, struct task_struct *p, bool preempt);
1085 
1086 	void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags);
1087 
1088 	struct task_struct * (*pick_next_task) (struct rq *rq);
1089 	void (*put_prev_task) (struct rq *rq, struct task_struct *p);
1090 
1091 #ifdef CONFIG_SMP
1092 	int  (*select_task_rq)(struct task_struct *p, int sd_flag, int flags);
1093 
1094 	void (*pre_schedule) (struct rq *this_rq, struct task_struct *task);
1095 	void (*post_schedule) (struct rq *this_rq);
1096 	void (*task_waking) (struct task_struct *task);
1097 	void (*task_woken) (struct rq *this_rq, struct task_struct *task);
1098 
1099 	void (*set_cpus_allowed)(struct task_struct *p,
1100 				 const struct cpumask *newmask);
1101 
1102 	void (*rq_online)(struct rq *rq);
1103 	void (*rq_offline)(struct rq *rq);
1104 #endif
1105 
1106 	void (*set_curr_task) (struct rq *rq);
1107 	void (*task_tick) (struct rq *rq, struct task_struct *p, int queued);
1108 	void (*task_fork) (struct task_struct *p);
1109 
1110 	void (*switched_from) (struct rq *this_rq, struct task_struct *task);
1111 	void (*switched_to) (struct rq *this_rq, struct task_struct *task);
1112 	void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
1113 			     int oldprio);
1114 
1115 	unsigned int (*get_rr_interval) (struct rq *rq,
1116 					 struct task_struct *task);
1117 
1118 #ifdef CONFIG_FAIR_GROUP_SCHED
1119 	void (*task_move_group) (struct task_struct *p, int on_rq);
1120 #endif
1121 };
1122 
1123 struct load_weight {
1124 	unsigned long weight, inv_weight;
1125 };
1126 
1127 #ifdef CONFIG_SCHEDSTATS
1128 struct sched_statistics {
1129 	u64			wait_start;
1130 	u64			wait_max;
1131 	u64			wait_count;
1132 	u64			wait_sum;
1133 	u64			iowait_count;
1134 	u64			iowait_sum;
1135 
1136 	u64			sleep_start;
1137 	u64			sleep_max;
1138 	s64			sum_sleep_runtime;
1139 
1140 	u64			block_start;
1141 	u64			block_max;
1142 	u64			exec_max;
1143 	u64			slice_max;
1144 
1145 	u64			nr_migrations_cold;
1146 	u64			nr_failed_migrations_affine;
1147 	u64			nr_failed_migrations_running;
1148 	u64			nr_failed_migrations_hot;
1149 	u64			nr_forced_migrations;
1150 
1151 	u64			nr_wakeups;
1152 	u64			nr_wakeups_sync;
1153 	u64			nr_wakeups_migrate;
1154 	u64			nr_wakeups_local;
1155 	u64			nr_wakeups_remote;
1156 	u64			nr_wakeups_affine;
1157 	u64			nr_wakeups_affine_attempts;
1158 	u64			nr_wakeups_passive;
1159 	u64			nr_wakeups_idle;
1160 };
1161 #endif
1162 
1163 struct sched_entity {
1164 	struct load_weight	load;		/* for load-balancing */
1165 	struct rb_node		run_node;
1166 	struct list_head	group_node;
1167 	unsigned int		on_rq;
1168 
1169 	u64			exec_start;
1170 	u64			sum_exec_runtime;
1171 	u64			vruntime;
1172 	u64			prev_sum_exec_runtime;
1173 
1174 	u64			nr_migrations;
1175 
1176 #ifdef CONFIG_SCHEDSTATS
1177 	struct sched_statistics statistics;
1178 #endif
1179 
1180 #ifdef CONFIG_FAIR_GROUP_SCHED
1181 	struct sched_entity	*parent;
1182 	/* rq on which this entity is (to be) queued: */
1183 	struct cfs_rq		*cfs_rq;
1184 	/* rq "owned" by this entity/group: */
1185 	struct cfs_rq		*my_q;
1186 #endif
1187 };
1188 
1189 struct sched_rt_entity {
1190 	struct list_head run_list;
1191 	unsigned long timeout;
1192 	unsigned int time_slice;
1193 	int nr_cpus_allowed;
1194 
1195 	struct sched_rt_entity *back;
1196 #ifdef CONFIG_RT_GROUP_SCHED
1197 	struct sched_rt_entity	*parent;
1198 	/* rq on which this entity is (to be) queued: */
1199 	struct rt_rq		*rt_rq;
1200 	/* rq "owned" by this entity/group: */
1201 	struct rt_rq		*my_q;
1202 #endif
1203 };
1204 
1205 struct rcu_node;
1206 
1207 enum perf_event_task_context {
1208 	perf_invalid_context = -1,
1209 	perf_hw_context = 0,
1210 	perf_sw_context,
1211 	perf_nr_task_contexts,
1212 };
1213 
1214 struct task_struct {
1215 	volatile long state;	/* -1 unrunnable, 0 runnable, >0 stopped */
1216 	void *stack;
1217 	atomic_t usage;
1218 	unsigned int flags;	/* per process flags, defined below */
1219 	unsigned int ptrace;
1220 
1221 #ifdef CONFIG_SMP
1222 	struct task_struct *wake_entry;
1223 	int on_cpu;
1224 #endif
1225 	int on_rq;
1226 
1227 	int prio, static_prio, normal_prio;
1228 	unsigned int rt_priority;
1229 	const struct sched_class *sched_class;
1230 	struct sched_entity se;
1231 	struct sched_rt_entity rt;
1232 
1233 #ifdef CONFIG_PREEMPT_NOTIFIERS
1234 	/* list of struct preempt_notifier: */
1235 	struct hlist_head preempt_notifiers;
1236 #endif
1237 
1238 	/*
1239 	 * fpu_counter contains the number of consecutive context switches
1240 	 * that the FPU is used. If this is over a threshold, the lazy fpu
1241 	 * saving becomes unlazy to save the trap. This is an unsigned char
1242 	 * so that after 256 times the counter wraps and the behavior turns
1243 	 * lazy again; this to deal with bursty apps that only use FPU for
1244 	 * a short time
1245 	 */
1246 	unsigned char fpu_counter;
1247 #ifdef CONFIG_BLK_DEV_IO_TRACE
1248 	unsigned int btrace_seq;
1249 #endif
1250 
1251 	unsigned int policy;
1252 	cpumask_t cpus_allowed;
1253 
1254 #ifdef CONFIG_PREEMPT_RCU
1255 	int rcu_read_lock_nesting;
1256 	char rcu_read_unlock_special;
1257 	struct list_head rcu_node_entry;
1258 #endif /* #ifdef CONFIG_PREEMPT_RCU */
1259 #ifdef CONFIG_TREE_PREEMPT_RCU
1260 	struct rcu_node *rcu_blocked_node;
1261 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
1262 #ifdef CONFIG_RCU_BOOST
1263 	struct rt_mutex *rcu_boost_mutex;
1264 #endif /* #ifdef CONFIG_RCU_BOOST */
1265 
1266 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
1267 	struct sched_info sched_info;
1268 #endif
1269 
1270 	struct list_head tasks;
1271 #ifdef CONFIG_SMP
1272 	struct plist_node pushable_tasks;
1273 #endif
1274 
1275 	struct mm_struct *mm, *active_mm;
1276 #ifdef CONFIG_COMPAT_BRK
1277 	unsigned brk_randomized:1;
1278 #endif
1279 #if defined(SPLIT_RSS_COUNTING)
1280 	struct task_rss_stat	rss_stat;
1281 #endif
1282 /* task state */
1283 	int exit_state;
1284 	int exit_code, exit_signal;
1285 	int pdeath_signal;  /*  The signal sent when the parent dies  */
1286 	unsigned int group_stop;	/* GROUP_STOP_*, siglock protected */
1287 	/* ??? */
1288 	unsigned int personality;
1289 	unsigned did_exec:1;
1290 	unsigned in_execve:1;	/* Tell the LSMs that the process is doing an
1291 				 * execve */
1292 	unsigned in_iowait:1;
1293 
1294 
1295 	/* Revert to default priority/policy when forking */
1296 	unsigned sched_reset_on_fork:1;
1297 	unsigned sched_contributes_to_load:1;
1298 
1299 	pid_t pid;
1300 	pid_t tgid;
1301 
1302 #ifdef CONFIG_CC_STACKPROTECTOR
1303 	/* Canary value for the -fstack-protector gcc feature */
1304 	unsigned long stack_canary;
1305 #endif
1306 
1307 	/*
1308 	 * pointers to (original) parent process, youngest child, younger sibling,
1309 	 * older sibling, respectively.  (p->father can be replaced with
1310 	 * p->real_parent->pid)
1311 	 */
1312 	struct task_struct *real_parent; /* real parent process */
1313 	struct task_struct *parent; /* recipient of SIGCHLD, wait4() reports */
1314 	/*
1315 	 * children/sibling forms the list of my natural children
1316 	 */
1317 	struct list_head children;	/* list of my children */
1318 	struct list_head sibling;	/* linkage in my parent's children list */
1319 	struct task_struct *group_leader;	/* threadgroup leader */
1320 
1321 	/*
1322 	 * ptraced is the list of tasks this task is using ptrace on.
1323 	 * This includes both natural children and PTRACE_ATTACH targets.
1324 	 * p->ptrace_entry is p's link on the p->parent->ptraced list.
1325 	 */
1326 	struct list_head ptraced;
1327 	struct list_head ptrace_entry;
1328 
1329 	/* PID/PID hash table linkage. */
1330 	struct pid_link pids[PIDTYPE_MAX];
1331 	struct list_head thread_group;
1332 
1333 	struct completion *vfork_done;		/* for vfork() */
1334 	int __user *set_child_tid;		/* CLONE_CHILD_SETTID */
1335 	int __user *clear_child_tid;		/* CLONE_CHILD_CLEARTID */
1336 
1337 	cputime_t utime, stime, utimescaled, stimescaled;
1338 	cputime_t gtime;
1339 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
1340 	cputime_t prev_utime, prev_stime;
1341 #endif
1342 	unsigned long nvcsw, nivcsw; /* context switch counts */
1343 	struct timespec start_time; 		/* monotonic time */
1344 	struct timespec real_start_time;	/* boot based time */
1345 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1346 	unsigned long min_flt, maj_flt;
1347 
1348 	struct task_cputime cputime_expires;
1349 	struct list_head cpu_timers[3];
1350 
1351 /* process credentials */
1352 	const struct cred __rcu *real_cred; /* objective and real subjective task
1353 					 * credentials (COW) */
1354 	const struct cred __rcu *cred;	/* effective (overridable) subjective task
1355 					 * credentials (COW) */
1356 	struct cred *replacement_session_keyring; /* for KEYCTL_SESSION_TO_PARENT */
1357 
1358 	char comm[TASK_COMM_LEN]; /* executable name excluding path
1359 				     - access with [gs]et_task_comm (which lock
1360 				       it with task_lock())
1361 				     - initialized normally by setup_new_exec */
1362 /* file system info */
1363 	int link_count, total_link_count;
1364 #ifdef CONFIG_SYSVIPC
1365 /* ipc stuff */
1366 	struct sysv_sem sysvsem;
1367 #endif
1368 #ifdef CONFIG_DETECT_HUNG_TASK
1369 /* hung task detection */
1370 	unsigned long last_switch_count;
1371 #endif
1372 /* CPU-specific state of this task */
1373 	struct thread_struct thread;
1374 /* filesystem information */
1375 	struct fs_struct *fs;
1376 /* open file information */
1377 	struct files_struct *files;
1378 /* namespaces */
1379 	struct nsproxy *nsproxy;
1380 /* signal handlers */
1381 	struct signal_struct *signal;
1382 	struct sighand_struct *sighand;
1383 
1384 	sigset_t blocked, real_blocked;
1385 	sigset_t saved_sigmask;	/* restored if set_restore_sigmask() was used */
1386 	struct sigpending pending;
1387 
1388 	unsigned long sas_ss_sp;
1389 	size_t sas_ss_size;
1390 	int (*notifier)(void *priv);
1391 	void *notifier_data;
1392 	sigset_t *notifier_mask;
1393 	struct audit_context *audit_context;
1394 #ifdef CONFIG_AUDITSYSCALL
1395 	uid_t loginuid;
1396 	unsigned int sessionid;
1397 #endif
1398 	seccomp_t seccomp;
1399 
1400 /* Thread group tracking */
1401    	u32 parent_exec_id;
1402    	u32 self_exec_id;
1403 /* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1404  * mempolicy */
1405 	spinlock_t alloc_lock;
1406 
1407 #ifdef CONFIG_GENERIC_HARDIRQS
1408 	/* IRQ handler threads */
1409 	struct irqaction *irqaction;
1410 #endif
1411 
1412 	/* Protection of the PI data structures: */
1413 	raw_spinlock_t pi_lock;
1414 
1415 #ifdef CONFIG_RT_MUTEXES
1416 	/* PI waiters blocked on a rt_mutex held by this task */
1417 	struct plist_head pi_waiters;
1418 	/* Deadlock detection and priority inheritance handling */
1419 	struct rt_mutex_waiter *pi_blocked_on;
1420 #endif
1421 
1422 #ifdef CONFIG_DEBUG_MUTEXES
1423 	/* mutex deadlock detection */
1424 	struct mutex_waiter *blocked_on;
1425 #endif
1426 #ifdef CONFIG_TRACE_IRQFLAGS
1427 	unsigned int irq_events;
1428 	unsigned long hardirq_enable_ip;
1429 	unsigned long hardirq_disable_ip;
1430 	unsigned int hardirq_enable_event;
1431 	unsigned int hardirq_disable_event;
1432 	int hardirqs_enabled;
1433 	int hardirq_context;
1434 	unsigned long softirq_disable_ip;
1435 	unsigned long softirq_enable_ip;
1436 	unsigned int softirq_disable_event;
1437 	unsigned int softirq_enable_event;
1438 	int softirqs_enabled;
1439 	int softirq_context;
1440 #endif
1441 #ifdef CONFIG_LOCKDEP
1442 # define MAX_LOCK_DEPTH 48UL
1443 	u64 curr_chain_key;
1444 	int lockdep_depth;
1445 	unsigned int lockdep_recursion;
1446 	struct held_lock held_locks[MAX_LOCK_DEPTH];
1447 	gfp_t lockdep_reclaim_gfp;
1448 #endif
1449 
1450 /* journalling filesystem info */
1451 	void *journal_info;
1452 
1453 /* stacked block device info */
1454 	struct bio_list *bio_list;
1455 
1456 #ifdef CONFIG_BLOCK
1457 /* stack plugging */
1458 	struct blk_plug *plug;
1459 #endif
1460 
1461 /* VM state */
1462 	struct reclaim_state *reclaim_state;
1463 
1464 	struct backing_dev_info *backing_dev_info;
1465 
1466 	struct io_context *io_context;
1467 
1468 	unsigned long ptrace_message;
1469 	siginfo_t *last_siginfo; /* For ptrace use.  */
1470 	struct task_io_accounting ioac;
1471 #if defined(CONFIG_TASK_XACCT)
1472 	u64 acct_rss_mem1;	/* accumulated rss usage */
1473 	u64 acct_vm_mem1;	/* accumulated virtual memory usage */
1474 	cputime_t acct_timexpd;	/* stime + utime since last update */
1475 #endif
1476 #ifdef CONFIG_CPUSETS
1477 	nodemask_t mems_allowed;	/* Protected by alloc_lock */
1478 	int mems_allowed_change_disable;
1479 	int cpuset_mem_spread_rotor;
1480 	int cpuset_slab_spread_rotor;
1481 #endif
1482 #ifdef CONFIG_CGROUPS
1483 	/* Control Group info protected by css_set_lock */
1484 	struct css_set __rcu *cgroups;
1485 	/* cg_list protected by css_set_lock and tsk->alloc_lock */
1486 	struct list_head cg_list;
1487 #endif
1488 #ifdef CONFIG_FUTEX
1489 	struct robust_list_head __user *robust_list;
1490 #ifdef CONFIG_COMPAT
1491 	struct compat_robust_list_head __user *compat_robust_list;
1492 #endif
1493 	struct list_head pi_state_list;
1494 	struct futex_pi_state *pi_state_cache;
1495 #endif
1496 #ifdef CONFIG_PERF_EVENTS
1497 	struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1498 	struct mutex perf_event_mutex;
1499 	struct list_head perf_event_list;
1500 #endif
1501 #ifdef CONFIG_NUMA
1502 	struct mempolicy *mempolicy;	/* Protected by alloc_lock */
1503 	short il_next;
1504 	short pref_node_fork;
1505 #endif
1506 	atomic_t fs_excl;	/* holding fs exclusive resources */
1507 	struct rcu_head rcu;
1508 
1509 	/*
1510 	 * cache last used pipe for splice
1511 	 */
1512 	struct pipe_inode_info *splice_pipe;
1513 #ifdef	CONFIG_TASK_DELAY_ACCT
1514 	struct task_delay_info *delays;
1515 #endif
1516 #ifdef CONFIG_FAULT_INJECTION
1517 	int make_it_fail;
1518 #endif
1519 	struct prop_local_single dirties;
1520 #ifdef CONFIG_LATENCYTOP
1521 	int latency_record_count;
1522 	struct latency_record latency_record[LT_SAVECOUNT];
1523 #endif
1524 	/*
1525 	 * time slack values; these are used to round up poll() and
1526 	 * select() etc timeout values. These are in nanoseconds.
1527 	 */
1528 	unsigned long timer_slack_ns;
1529 	unsigned long default_timer_slack_ns;
1530 
1531 	struct list_head	*scm_work_list;
1532 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1533 	/* Index of current stored address in ret_stack */
1534 	int curr_ret_stack;
1535 	/* Stack of return addresses for return function tracing */
1536 	struct ftrace_ret_stack	*ret_stack;
1537 	/* time stamp for last schedule */
1538 	unsigned long long ftrace_timestamp;
1539 	/*
1540 	 * Number of functions that haven't been traced
1541 	 * because of depth overrun.
1542 	 */
1543 	atomic_t trace_overrun;
1544 	/* Pause for the tracing */
1545 	atomic_t tracing_graph_pause;
1546 #endif
1547 #ifdef CONFIG_TRACING
1548 	/* state flags for use by tracers */
1549 	unsigned long trace;
1550 	/* bitmask and counter of trace recursion */
1551 	unsigned long trace_recursion;
1552 #endif /* CONFIG_TRACING */
1553 #ifdef CONFIG_CGROUP_MEM_RES_CTLR /* memcg uses this to do batch job */
1554 	struct memcg_batch_info {
1555 		int do_batch;	/* incremented when batch uncharge started */
1556 		struct mem_cgroup *memcg; /* target memcg of uncharge */
1557 		unsigned long nr_pages;	/* uncharged usage */
1558 		unsigned long memsw_nr_pages; /* uncharged mem+swap usage */
1559 	} memcg_batch;
1560 #endif
1561 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1562 	atomic_t ptrace_bp_refcnt;
1563 #endif
1564 };
1565 
1566 /* Future-safe accessor for struct task_struct's cpus_allowed. */
1567 #define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
1568 
1569 /*
1570  * Priority of a process goes from 0..MAX_PRIO-1, valid RT
1571  * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
1572  * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority
1573  * values are inverted: lower p->prio value means higher priority.
1574  *
1575  * The MAX_USER_RT_PRIO value allows the actual maximum
1576  * RT priority to be separate from the value exported to
1577  * user-space.  This allows kernel threads to set their
1578  * priority to a value higher than any user task. Note:
1579  * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
1580  */
1581 
1582 #define MAX_USER_RT_PRIO	100
1583 #define MAX_RT_PRIO		MAX_USER_RT_PRIO
1584 
1585 #define MAX_PRIO		(MAX_RT_PRIO + 40)
1586 #define DEFAULT_PRIO		(MAX_RT_PRIO + 20)
1587 
1588 static inline int rt_prio(int prio)
1589 {
1590 	if (unlikely(prio < MAX_RT_PRIO))
1591 		return 1;
1592 	return 0;
1593 }
1594 
1595 static inline int rt_task(struct task_struct *p)
1596 {
1597 	return rt_prio(p->prio);
1598 }
1599 
1600 static inline struct pid *task_pid(struct task_struct *task)
1601 {
1602 	return task->pids[PIDTYPE_PID].pid;
1603 }
1604 
1605 static inline struct pid *task_tgid(struct task_struct *task)
1606 {
1607 	return task->group_leader->pids[PIDTYPE_PID].pid;
1608 }
1609 
1610 /*
1611  * Without tasklist or rcu lock it is not safe to dereference
1612  * the result of task_pgrp/task_session even if task == current,
1613  * we can race with another thread doing sys_setsid/sys_setpgid.
1614  */
1615 static inline struct pid *task_pgrp(struct task_struct *task)
1616 {
1617 	return task->group_leader->pids[PIDTYPE_PGID].pid;
1618 }
1619 
1620 static inline struct pid *task_session(struct task_struct *task)
1621 {
1622 	return task->group_leader->pids[PIDTYPE_SID].pid;
1623 }
1624 
1625 struct pid_namespace;
1626 
1627 /*
1628  * the helpers to get the task's different pids as they are seen
1629  * from various namespaces
1630  *
1631  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1632  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1633  *                     current.
1634  * task_xid_nr_ns()  : id seen from the ns specified;
1635  *
1636  * set_task_vxid()   : assigns a virtual id to a task;
1637  *
1638  * see also pid_nr() etc in include/linux/pid.h
1639  */
1640 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
1641 			struct pid_namespace *ns);
1642 
1643 static inline pid_t task_pid_nr(struct task_struct *tsk)
1644 {
1645 	return tsk->pid;
1646 }
1647 
1648 static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
1649 					struct pid_namespace *ns)
1650 {
1651 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1652 }
1653 
1654 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1655 {
1656 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1657 }
1658 
1659 
1660 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1661 {
1662 	return tsk->tgid;
1663 }
1664 
1665 pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1666 
1667 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1668 {
1669 	return pid_vnr(task_tgid(tsk));
1670 }
1671 
1672 
1673 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
1674 					struct pid_namespace *ns)
1675 {
1676 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1677 }
1678 
1679 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1680 {
1681 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1682 }
1683 
1684 
1685 static inline pid_t task_session_nr_ns(struct task_struct *tsk,
1686 					struct pid_namespace *ns)
1687 {
1688 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1689 }
1690 
1691 static inline pid_t task_session_vnr(struct task_struct *tsk)
1692 {
1693 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1694 }
1695 
1696 /* obsolete, do not use */
1697 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1698 {
1699 	return task_pgrp_nr_ns(tsk, &init_pid_ns);
1700 }
1701 
1702 /**
1703  * pid_alive - check that a task structure is not stale
1704  * @p: Task structure to be checked.
1705  *
1706  * Test if a process is not yet dead (at most zombie state)
1707  * If pid_alive fails, then pointers within the task structure
1708  * can be stale and must not be dereferenced.
1709  */
1710 static inline int pid_alive(struct task_struct *p)
1711 {
1712 	return p->pids[PIDTYPE_PID].pid != NULL;
1713 }
1714 
1715 /**
1716  * is_global_init - check if a task structure is init
1717  * @tsk: Task structure to be checked.
1718  *
1719  * Check if a task structure is the first user space task the kernel created.
1720  */
1721 static inline int is_global_init(struct task_struct *tsk)
1722 {
1723 	return tsk->pid == 1;
1724 }
1725 
1726 /*
1727  * is_container_init:
1728  * check whether in the task is init in its own pid namespace.
1729  */
1730 extern int is_container_init(struct task_struct *tsk);
1731 
1732 extern struct pid *cad_pid;
1733 
1734 extern void free_task(struct task_struct *tsk);
1735 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
1736 
1737 extern void __put_task_struct(struct task_struct *t);
1738 
1739 static inline void put_task_struct(struct task_struct *t)
1740 {
1741 	if (atomic_dec_and_test(&t->usage))
1742 		__put_task_struct(t);
1743 }
1744 
1745 extern void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st);
1746 extern void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st);
1747 
1748 /*
1749  * Per process flags
1750  */
1751 #define PF_STARTING	0x00000002	/* being created */
1752 #define PF_EXITING	0x00000004	/* getting shut down */
1753 #define PF_EXITPIDONE	0x00000008	/* pi exit done on shut down */
1754 #define PF_VCPU		0x00000010	/* I'm a virtual CPU */
1755 #define PF_WQ_WORKER	0x00000020	/* I'm a workqueue worker */
1756 #define PF_FORKNOEXEC	0x00000040	/* forked but didn't exec */
1757 #define PF_MCE_PROCESS  0x00000080      /* process policy on mce errors */
1758 #define PF_SUPERPRIV	0x00000100	/* used super-user privileges */
1759 #define PF_DUMPCORE	0x00000200	/* dumped core */
1760 #define PF_SIGNALED	0x00000400	/* killed by a signal */
1761 #define PF_MEMALLOC	0x00000800	/* Allocating memory */
1762 #define PF_USED_MATH	0x00002000	/* if unset the fpu must be initialized before use */
1763 #define PF_FREEZING	0x00004000	/* freeze in progress. do not account to load */
1764 #define PF_NOFREEZE	0x00008000	/* this thread should not be frozen */
1765 #define PF_FROZEN	0x00010000	/* frozen for system suspend */
1766 #define PF_FSTRANS	0x00020000	/* inside a filesystem transaction */
1767 #define PF_KSWAPD	0x00040000	/* I am kswapd */
1768 #define PF_LESS_THROTTLE 0x00100000	/* Throttle me less: I clean memory */
1769 #define PF_KTHREAD	0x00200000	/* I am a kernel thread */
1770 #define PF_RANDOMIZE	0x00400000	/* randomize virtual address space */
1771 #define PF_SWAPWRITE	0x00800000	/* Allowed to write to swap */
1772 #define PF_SPREAD_PAGE	0x01000000	/* Spread page cache over cpuset */
1773 #define PF_SPREAD_SLAB	0x02000000	/* Spread some slab caches over cpuset */
1774 #define PF_THREAD_BOUND	0x04000000	/* Thread bound to specific cpu */
1775 #define PF_MCE_EARLY    0x08000000      /* Early kill for mce process policy */
1776 #define PF_MEMPOLICY	0x10000000	/* Non-default NUMA mempolicy */
1777 #define PF_MUTEX_TESTER	0x20000000	/* Thread belongs to the rt mutex tester */
1778 #define PF_FREEZER_SKIP	0x40000000	/* Freezer should not count it as freezable */
1779 #define PF_FREEZER_NOSIG 0x80000000	/* Freezer won't send signals to it */
1780 
1781 /*
1782  * Only the _current_ task can read/write to tsk->flags, but other
1783  * tasks can access tsk->flags in readonly mode for example
1784  * with tsk_used_math (like during threaded core dumping).
1785  * There is however an exception to this rule during ptrace
1786  * or during fork: the ptracer task is allowed to write to the
1787  * child->flags of its traced child (same goes for fork, the parent
1788  * can write to the child->flags), because we're guaranteed the
1789  * child is not running and in turn not changing child->flags
1790  * at the same time the parent does it.
1791  */
1792 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1793 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1794 #define clear_used_math() clear_stopped_child_used_math(current)
1795 #define set_used_math() set_stopped_child_used_math(current)
1796 #define conditional_stopped_child_used_math(condition, child) \
1797 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1798 #define conditional_used_math(condition) \
1799 	conditional_stopped_child_used_math(condition, current)
1800 #define copy_to_stopped_child_used_math(child) \
1801 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1802 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1803 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1804 #define used_math() tsk_used_math(current)
1805 
1806 /*
1807  * task->group_stop flags
1808  */
1809 #define GROUP_STOP_SIGMASK	0xffff    /* signr of the last group stop */
1810 #define GROUP_STOP_PENDING	(1 << 16) /* task should stop for group stop */
1811 #define GROUP_STOP_CONSUME	(1 << 17) /* consume group stop count */
1812 #define GROUP_STOP_TRAPPING	(1 << 18) /* switching from STOPPED to TRACED */
1813 #define GROUP_STOP_DEQUEUED	(1 << 19) /* stop signal dequeued */
1814 
1815 extern void task_clear_group_stop_pending(struct task_struct *task);
1816 
1817 #ifdef CONFIG_PREEMPT_RCU
1818 
1819 #define RCU_READ_UNLOCK_BLOCKED (1 << 0) /* blocked while in RCU read-side. */
1820 #define RCU_READ_UNLOCK_BOOSTED (1 << 1) /* boosted while in RCU read-side. */
1821 #define RCU_READ_UNLOCK_NEED_QS (1 << 2) /* RCU core needs CPU response. */
1822 
1823 static inline void rcu_copy_process(struct task_struct *p)
1824 {
1825 	p->rcu_read_lock_nesting = 0;
1826 	p->rcu_read_unlock_special = 0;
1827 #ifdef CONFIG_TREE_PREEMPT_RCU
1828 	p->rcu_blocked_node = NULL;
1829 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
1830 #ifdef CONFIG_RCU_BOOST
1831 	p->rcu_boost_mutex = NULL;
1832 #endif /* #ifdef CONFIG_RCU_BOOST */
1833 	INIT_LIST_HEAD(&p->rcu_node_entry);
1834 }
1835 
1836 #else
1837 
1838 static inline void rcu_copy_process(struct task_struct *p)
1839 {
1840 }
1841 
1842 #endif
1843 
1844 #ifdef CONFIG_SMP
1845 extern void do_set_cpus_allowed(struct task_struct *p,
1846 			       const struct cpumask *new_mask);
1847 
1848 extern int set_cpus_allowed_ptr(struct task_struct *p,
1849 				const struct cpumask *new_mask);
1850 #else
1851 static inline void do_set_cpus_allowed(struct task_struct *p,
1852 				      const struct cpumask *new_mask)
1853 {
1854 }
1855 static inline int set_cpus_allowed_ptr(struct task_struct *p,
1856 				       const struct cpumask *new_mask)
1857 {
1858 	if (!cpumask_test_cpu(0, new_mask))
1859 		return -EINVAL;
1860 	return 0;
1861 }
1862 #endif
1863 
1864 #ifndef CONFIG_CPUMASK_OFFSTACK
1865 static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
1866 {
1867 	return set_cpus_allowed_ptr(p, &new_mask);
1868 }
1869 #endif
1870 
1871 /*
1872  * Do not use outside of architecture code which knows its limitations.
1873  *
1874  * sched_clock() has no promise of monotonicity or bounded drift between
1875  * CPUs, use (which you should not) requires disabling IRQs.
1876  *
1877  * Please use one of the three interfaces below.
1878  */
1879 extern unsigned long long notrace sched_clock(void);
1880 /*
1881  * See the comment in kernel/sched_clock.c
1882  */
1883 extern u64 cpu_clock(int cpu);
1884 extern u64 local_clock(void);
1885 extern u64 sched_clock_cpu(int cpu);
1886 
1887 
1888 extern void sched_clock_init(void);
1889 
1890 #ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
1891 static inline void sched_clock_tick(void)
1892 {
1893 }
1894 
1895 static inline void sched_clock_idle_sleep_event(void)
1896 {
1897 }
1898 
1899 static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
1900 {
1901 }
1902 #else
1903 /*
1904  * Architectures can set this to 1 if they have specified
1905  * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
1906  * but then during bootup it turns out that sched_clock()
1907  * is reliable after all:
1908  */
1909 extern int sched_clock_stable;
1910 
1911 extern void sched_clock_tick(void);
1912 extern void sched_clock_idle_sleep_event(void);
1913 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
1914 #endif
1915 
1916 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
1917 /*
1918  * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
1919  * The reason for this explicit opt-in is not to have perf penalty with
1920  * slow sched_clocks.
1921  */
1922 extern void enable_sched_clock_irqtime(void);
1923 extern void disable_sched_clock_irqtime(void);
1924 #else
1925 static inline void enable_sched_clock_irqtime(void) {}
1926 static inline void disable_sched_clock_irqtime(void) {}
1927 #endif
1928 
1929 extern unsigned long long
1930 task_sched_runtime(struct task_struct *task);
1931 extern unsigned long long thread_group_sched_runtime(struct task_struct *task);
1932 
1933 /* sched_exec is called by processes performing an exec */
1934 #ifdef CONFIG_SMP
1935 extern void sched_exec(void);
1936 #else
1937 #define sched_exec()   {}
1938 #endif
1939 
1940 extern void sched_clock_idle_sleep_event(void);
1941 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
1942 
1943 #ifdef CONFIG_HOTPLUG_CPU
1944 extern void idle_task_exit(void);
1945 #else
1946 static inline void idle_task_exit(void) {}
1947 #endif
1948 
1949 #if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP)
1950 extern void wake_up_idle_cpu(int cpu);
1951 #else
1952 static inline void wake_up_idle_cpu(int cpu) { }
1953 #endif
1954 
1955 extern unsigned int sysctl_sched_latency;
1956 extern unsigned int sysctl_sched_min_granularity;
1957 extern unsigned int sysctl_sched_wakeup_granularity;
1958 extern unsigned int sysctl_sched_child_runs_first;
1959 
1960 enum sched_tunable_scaling {
1961 	SCHED_TUNABLESCALING_NONE,
1962 	SCHED_TUNABLESCALING_LOG,
1963 	SCHED_TUNABLESCALING_LINEAR,
1964 	SCHED_TUNABLESCALING_END,
1965 };
1966 extern enum sched_tunable_scaling sysctl_sched_tunable_scaling;
1967 
1968 #ifdef CONFIG_SCHED_DEBUG
1969 extern unsigned int sysctl_sched_migration_cost;
1970 extern unsigned int sysctl_sched_nr_migrate;
1971 extern unsigned int sysctl_sched_time_avg;
1972 extern unsigned int sysctl_timer_migration;
1973 extern unsigned int sysctl_sched_shares_window;
1974 
1975 int sched_proc_update_handler(struct ctl_table *table, int write,
1976 		void __user *buffer, size_t *length,
1977 		loff_t *ppos);
1978 #endif
1979 #ifdef CONFIG_SCHED_DEBUG
1980 static inline unsigned int get_sysctl_timer_migration(void)
1981 {
1982 	return sysctl_timer_migration;
1983 }
1984 #else
1985 static inline unsigned int get_sysctl_timer_migration(void)
1986 {
1987 	return 1;
1988 }
1989 #endif
1990 extern unsigned int sysctl_sched_rt_period;
1991 extern int sysctl_sched_rt_runtime;
1992 
1993 int sched_rt_handler(struct ctl_table *table, int write,
1994 		void __user *buffer, size_t *lenp,
1995 		loff_t *ppos);
1996 
1997 #ifdef CONFIG_SCHED_AUTOGROUP
1998 extern unsigned int sysctl_sched_autogroup_enabled;
1999 
2000 extern void sched_autogroup_create_attach(struct task_struct *p);
2001 extern void sched_autogroup_detach(struct task_struct *p);
2002 extern void sched_autogroup_fork(struct signal_struct *sig);
2003 extern void sched_autogroup_exit(struct signal_struct *sig);
2004 #ifdef CONFIG_PROC_FS
2005 extern void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m);
2006 extern int proc_sched_autogroup_set_nice(struct task_struct *p, int *nice);
2007 #endif
2008 #else
2009 static inline void sched_autogroup_create_attach(struct task_struct *p) { }
2010 static inline void sched_autogroup_detach(struct task_struct *p) { }
2011 static inline void sched_autogroup_fork(struct signal_struct *sig) { }
2012 static inline void sched_autogroup_exit(struct signal_struct *sig) { }
2013 #endif
2014 
2015 #ifdef CONFIG_RT_MUTEXES
2016 extern int rt_mutex_getprio(struct task_struct *p);
2017 extern void rt_mutex_setprio(struct task_struct *p, int prio);
2018 extern void rt_mutex_adjust_pi(struct task_struct *p);
2019 #else
2020 static inline int rt_mutex_getprio(struct task_struct *p)
2021 {
2022 	return p->normal_prio;
2023 }
2024 # define rt_mutex_adjust_pi(p)		do { } while (0)
2025 #endif
2026 
2027 extern bool yield_to(struct task_struct *p, bool preempt);
2028 extern void set_user_nice(struct task_struct *p, long nice);
2029 extern int task_prio(const struct task_struct *p);
2030 extern int task_nice(const struct task_struct *p);
2031 extern int can_nice(const struct task_struct *p, const int nice);
2032 extern int task_curr(const struct task_struct *p);
2033 extern int idle_cpu(int cpu);
2034 extern int sched_setscheduler(struct task_struct *, int,
2035 			      const struct sched_param *);
2036 extern int sched_setscheduler_nocheck(struct task_struct *, int,
2037 				      const struct sched_param *);
2038 extern struct task_struct *idle_task(int cpu);
2039 extern struct task_struct *curr_task(int cpu);
2040 extern void set_curr_task(int cpu, struct task_struct *p);
2041 
2042 void yield(void);
2043 
2044 /*
2045  * The default (Linux) execution domain.
2046  */
2047 extern struct exec_domain	default_exec_domain;
2048 
2049 union thread_union {
2050 	struct thread_info thread_info;
2051 	unsigned long stack[THREAD_SIZE/sizeof(long)];
2052 };
2053 
2054 #ifndef __HAVE_ARCH_KSTACK_END
2055 static inline int kstack_end(void *addr)
2056 {
2057 	/* Reliable end of stack detection:
2058 	 * Some APM bios versions misalign the stack
2059 	 */
2060 	return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
2061 }
2062 #endif
2063 
2064 extern union thread_union init_thread_union;
2065 extern struct task_struct init_task;
2066 
2067 extern struct   mm_struct init_mm;
2068 
2069 extern struct pid_namespace init_pid_ns;
2070 
2071 /*
2072  * find a task by one of its numerical ids
2073  *
2074  * find_task_by_pid_ns():
2075  *      finds a task by its pid in the specified namespace
2076  * find_task_by_vpid():
2077  *      finds a task by its virtual pid
2078  *
2079  * see also find_vpid() etc in include/linux/pid.h
2080  */
2081 
2082 extern struct task_struct *find_task_by_vpid(pid_t nr);
2083 extern struct task_struct *find_task_by_pid_ns(pid_t nr,
2084 		struct pid_namespace *ns);
2085 
2086 extern void __set_special_pids(struct pid *pid);
2087 
2088 /* per-UID process charging. */
2089 extern struct user_struct * alloc_uid(struct user_namespace *, uid_t);
2090 static inline struct user_struct *get_uid(struct user_struct *u)
2091 {
2092 	atomic_inc(&u->__count);
2093 	return u;
2094 }
2095 extern void free_uid(struct user_struct *);
2096 extern void release_uids(struct user_namespace *ns);
2097 
2098 #include <asm/current.h>
2099 
2100 extern void xtime_update(unsigned long ticks);
2101 
2102 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2103 extern int wake_up_process(struct task_struct *tsk);
2104 extern void wake_up_new_task(struct task_struct *tsk);
2105 #ifdef CONFIG_SMP
2106  extern void kick_process(struct task_struct *tsk);
2107 #else
2108  static inline void kick_process(struct task_struct *tsk) { }
2109 #endif
2110 extern void sched_fork(struct task_struct *p);
2111 extern void sched_dead(struct task_struct *p);
2112 
2113 extern void proc_caches_init(void);
2114 extern void flush_signals(struct task_struct *);
2115 extern void __flush_signals(struct task_struct *);
2116 extern void ignore_signals(struct task_struct *);
2117 extern void flush_signal_handlers(struct task_struct *, int force_default);
2118 extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
2119 
2120 static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
2121 {
2122 	unsigned long flags;
2123 	int ret;
2124 
2125 	spin_lock_irqsave(&tsk->sighand->siglock, flags);
2126 	ret = dequeue_signal(tsk, mask, info);
2127 	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
2128 
2129 	return ret;
2130 }
2131 
2132 extern void block_all_signals(int (*notifier)(void *priv), void *priv,
2133 			      sigset_t *mask);
2134 extern void unblock_all_signals(void);
2135 extern void release_task(struct task_struct * p);
2136 extern int send_sig_info(int, struct siginfo *, struct task_struct *);
2137 extern int force_sigsegv(int, struct task_struct *);
2138 extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2139 extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
2140 extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2141 extern int kill_pid_info_as_uid(int, struct siginfo *, struct pid *, uid_t, uid_t, u32);
2142 extern int kill_pgrp(struct pid *pid, int sig, int priv);
2143 extern int kill_pid(struct pid *pid, int sig, int priv);
2144 extern int kill_proc_info(int, struct siginfo *, pid_t);
2145 extern int do_notify_parent(struct task_struct *, int);
2146 extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
2147 extern void force_sig(int, struct task_struct *);
2148 extern int send_sig(int, struct task_struct *, int);
2149 extern int zap_other_threads(struct task_struct *p);
2150 extern struct sigqueue *sigqueue_alloc(void);
2151 extern void sigqueue_free(struct sigqueue *);
2152 extern int send_sigqueue(struct sigqueue *,  struct task_struct *, int group);
2153 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
2154 extern int do_sigaltstack(const stack_t __user *, stack_t __user *, unsigned long);
2155 
2156 static inline int kill_cad_pid(int sig, int priv)
2157 {
2158 	return kill_pid(cad_pid, sig, priv);
2159 }
2160 
2161 /* These can be the second arg to send_sig_info/send_group_sig_info.  */
2162 #define SEND_SIG_NOINFO ((struct siginfo *) 0)
2163 #define SEND_SIG_PRIV	((struct siginfo *) 1)
2164 #define SEND_SIG_FORCED	((struct siginfo *) 2)
2165 
2166 /*
2167  * True if we are on the alternate signal stack.
2168  */
2169 static inline int on_sig_stack(unsigned long sp)
2170 {
2171 #ifdef CONFIG_STACK_GROWSUP
2172 	return sp >= current->sas_ss_sp &&
2173 		sp - current->sas_ss_sp < current->sas_ss_size;
2174 #else
2175 	return sp > current->sas_ss_sp &&
2176 		sp - current->sas_ss_sp <= current->sas_ss_size;
2177 #endif
2178 }
2179 
2180 static inline int sas_ss_flags(unsigned long sp)
2181 {
2182 	return (current->sas_ss_size == 0 ? SS_DISABLE
2183 		: on_sig_stack(sp) ? SS_ONSTACK : 0);
2184 }
2185 
2186 /*
2187  * Routines for handling mm_structs
2188  */
2189 extern struct mm_struct * mm_alloc(void);
2190 
2191 /* mmdrop drops the mm and the page tables */
2192 extern void __mmdrop(struct mm_struct *);
2193 static inline void mmdrop(struct mm_struct * mm)
2194 {
2195 	if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2196 		__mmdrop(mm);
2197 }
2198 
2199 /* mmput gets rid of the mappings and all user-space */
2200 extern void mmput(struct mm_struct *);
2201 /* Grab a reference to a task's mm, if it is not already going away */
2202 extern struct mm_struct *get_task_mm(struct task_struct *task);
2203 /* Remove the current tasks stale references to the old mm_struct */
2204 extern void mm_release(struct task_struct *, struct mm_struct *);
2205 /* Allocate a new mm structure and copy contents from tsk->mm */
2206 extern struct mm_struct *dup_mm(struct task_struct *tsk);
2207 
2208 extern int copy_thread(unsigned long, unsigned long, unsigned long,
2209 			struct task_struct *, struct pt_regs *);
2210 extern void flush_thread(void);
2211 extern void exit_thread(void);
2212 
2213 extern void exit_files(struct task_struct *);
2214 extern void __cleanup_sighand(struct sighand_struct *);
2215 
2216 extern void exit_itimers(struct signal_struct *);
2217 extern void flush_itimer_signals(void);
2218 
2219 extern NORET_TYPE void do_group_exit(int);
2220 
2221 extern void daemonize(const char *, ...);
2222 extern int allow_signal(int);
2223 extern int disallow_signal(int);
2224 
2225 extern int do_execve(const char *,
2226 		     const char __user * const __user *,
2227 		     const char __user * const __user *, struct pt_regs *);
2228 extern long do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *);
2229 struct task_struct *fork_idle(int);
2230 
2231 extern void set_task_comm(struct task_struct *tsk, char *from);
2232 extern char *get_task_comm(char *to, struct task_struct *tsk);
2233 
2234 #ifdef CONFIG_SMP
2235 void scheduler_ipi(void);
2236 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
2237 #else
2238 static inline void scheduler_ipi(void) { }
2239 static inline unsigned long wait_task_inactive(struct task_struct *p,
2240 					       long match_state)
2241 {
2242 	return 1;
2243 }
2244 #endif
2245 
2246 #define next_task(p) \
2247 	list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
2248 
2249 #define for_each_process(p) \
2250 	for (p = &init_task ; (p = next_task(p)) != &init_task ; )
2251 
2252 extern bool current_is_single_threaded(void);
2253 
2254 /*
2255  * Careful: do_each_thread/while_each_thread is a double loop so
2256  *          'break' will not work as expected - use goto instead.
2257  */
2258 #define do_each_thread(g, t) \
2259 	for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
2260 
2261 #define while_each_thread(g, t) \
2262 	while ((t = next_thread(t)) != g)
2263 
2264 static inline int get_nr_threads(struct task_struct *tsk)
2265 {
2266 	return tsk->signal->nr_threads;
2267 }
2268 
2269 /* de_thread depends on thread_group_leader not being a pid based check */
2270 #define thread_group_leader(p)	(p == p->group_leader)
2271 
2272 /* Do to the insanities of de_thread it is possible for a process
2273  * to have the pid of the thread group leader without actually being
2274  * the thread group leader.  For iteration through the pids in proc
2275  * all we care about is that we have a task with the appropriate
2276  * pid, we don't actually care if we have the right task.
2277  */
2278 static inline int has_group_leader_pid(struct task_struct *p)
2279 {
2280 	return p->pid == p->tgid;
2281 }
2282 
2283 static inline
2284 int same_thread_group(struct task_struct *p1, struct task_struct *p2)
2285 {
2286 	return p1->tgid == p2->tgid;
2287 }
2288 
2289 static inline struct task_struct *next_thread(const struct task_struct *p)
2290 {
2291 	return list_entry_rcu(p->thread_group.next,
2292 			      struct task_struct, thread_group);
2293 }
2294 
2295 static inline int thread_group_empty(struct task_struct *p)
2296 {
2297 	return list_empty(&p->thread_group);
2298 }
2299 
2300 #define delay_group_leader(p) \
2301 		(thread_group_leader(p) && !thread_group_empty(p))
2302 
2303 static inline int task_detached(struct task_struct *p)
2304 {
2305 	return p->exit_signal == -1;
2306 }
2307 
2308 /*
2309  * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
2310  * subscriptions and synchronises with wait4().  Also used in procfs.  Also
2311  * pins the final release of task.io_context.  Also protects ->cpuset and
2312  * ->cgroup.subsys[].
2313  *
2314  * Nests both inside and outside of read_lock(&tasklist_lock).
2315  * It must not be nested with write_lock_irq(&tasklist_lock),
2316  * neither inside nor outside.
2317  */
2318 static inline void task_lock(struct task_struct *p)
2319 {
2320 	spin_lock(&p->alloc_lock);
2321 }
2322 
2323 static inline void task_unlock(struct task_struct *p)
2324 {
2325 	spin_unlock(&p->alloc_lock);
2326 }
2327 
2328 extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
2329 							unsigned long *flags);
2330 
2331 #define lock_task_sighand(tsk, flags)					\
2332 ({	struct sighand_struct *__ss;					\
2333 	__cond_lock(&(tsk)->sighand->siglock,				\
2334 		    (__ss = __lock_task_sighand(tsk, flags)));		\
2335 	__ss;								\
2336 })									\
2337 
2338 static inline void unlock_task_sighand(struct task_struct *tsk,
2339 						unsigned long *flags)
2340 {
2341 	spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
2342 }
2343 
2344 /* See the declaration of threadgroup_fork_lock in signal_struct. */
2345 #ifdef CONFIG_CGROUPS
2346 static inline void threadgroup_fork_read_lock(struct task_struct *tsk)
2347 {
2348 	down_read(&tsk->signal->threadgroup_fork_lock);
2349 }
2350 static inline void threadgroup_fork_read_unlock(struct task_struct *tsk)
2351 {
2352 	up_read(&tsk->signal->threadgroup_fork_lock);
2353 }
2354 static inline void threadgroup_fork_write_lock(struct task_struct *tsk)
2355 {
2356 	down_write(&tsk->signal->threadgroup_fork_lock);
2357 }
2358 static inline void threadgroup_fork_write_unlock(struct task_struct *tsk)
2359 {
2360 	up_write(&tsk->signal->threadgroup_fork_lock);
2361 }
2362 #else
2363 static inline void threadgroup_fork_read_lock(struct task_struct *tsk) {}
2364 static inline void threadgroup_fork_read_unlock(struct task_struct *tsk) {}
2365 static inline void threadgroup_fork_write_lock(struct task_struct *tsk) {}
2366 static inline void threadgroup_fork_write_unlock(struct task_struct *tsk) {}
2367 #endif
2368 
2369 #ifndef __HAVE_THREAD_FUNCTIONS
2370 
2371 #define task_thread_info(task)	((struct thread_info *)(task)->stack)
2372 #define task_stack_page(task)	((task)->stack)
2373 
2374 static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
2375 {
2376 	*task_thread_info(p) = *task_thread_info(org);
2377 	task_thread_info(p)->task = p;
2378 }
2379 
2380 static inline unsigned long *end_of_stack(struct task_struct *p)
2381 {
2382 	return (unsigned long *)(task_thread_info(p) + 1);
2383 }
2384 
2385 #endif
2386 
2387 static inline int object_is_on_stack(void *obj)
2388 {
2389 	void *stack = task_stack_page(current);
2390 
2391 	return (obj >= stack) && (obj < (stack + THREAD_SIZE));
2392 }
2393 
2394 extern void thread_info_cache_init(void);
2395 
2396 #ifdef CONFIG_DEBUG_STACK_USAGE
2397 static inline unsigned long stack_not_used(struct task_struct *p)
2398 {
2399 	unsigned long *n = end_of_stack(p);
2400 
2401 	do { 	/* Skip over canary */
2402 		n++;
2403 	} while (!*n);
2404 
2405 	return (unsigned long)n - (unsigned long)end_of_stack(p);
2406 }
2407 #endif
2408 
2409 /* set thread flags in other task's structures
2410  * - see asm/thread_info.h for TIF_xxxx flags available
2411  */
2412 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2413 {
2414 	set_ti_thread_flag(task_thread_info(tsk), flag);
2415 }
2416 
2417 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2418 {
2419 	clear_ti_thread_flag(task_thread_info(tsk), flag);
2420 }
2421 
2422 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2423 {
2424 	return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2425 }
2426 
2427 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2428 {
2429 	return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2430 }
2431 
2432 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2433 {
2434 	return test_ti_thread_flag(task_thread_info(tsk), flag);
2435 }
2436 
2437 static inline void set_tsk_need_resched(struct task_struct *tsk)
2438 {
2439 	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2440 }
2441 
2442 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2443 {
2444 	clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2445 }
2446 
2447 static inline int test_tsk_need_resched(struct task_struct *tsk)
2448 {
2449 	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2450 }
2451 
2452 static inline int restart_syscall(void)
2453 {
2454 	set_tsk_thread_flag(current, TIF_SIGPENDING);
2455 	return -ERESTARTNOINTR;
2456 }
2457 
2458 static inline int signal_pending(struct task_struct *p)
2459 {
2460 	return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
2461 }
2462 
2463 static inline int __fatal_signal_pending(struct task_struct *p)
2464 {
2465 	return unlikely(sigismember(&p->pending.signal, SIGKILL));
2466 }
2467 
2468 static inline int fatal_signal_pending(struct task_struct *p)
2469 {
2470 	return signal_pending(p) && __fatal_signal_pending(p);
2471 }
2472 
2473 static inline int signal_pending_state(long state, struct task_struct *p)
2474 {
2475 	if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
2476 		return 0;
2477 	if (!signal_pending(p))
2478 		return 0;
2479 
2480 	return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
2481 }
2482 
2483 static inline int need_resched(void)
2484 {
2485 	return unlikely(test_thread_flag(TIF_NEED_RESCHED));
2486 }
2487 
2488 /*
2489  * cond_resched() and cond_resched_lock(): latency reduction via
2490  * explicit rescheduling in places that are safe. The return
2491  * value indicates whether a reschedule was done in fact.
2492  * cond_resched_lock() will drop the spinlock before scheduling,
2493  * cond_resched_softirq() will enable bhs before scheduling.
2494  */
2495 extern int _cond_resched(void);
2496 
2497 #define cond_resched() ({			\
2498 	__might_sleep(__FILE__, __LINE__, 0);	\
2499 	_cond_resched();			\
2500 })
2501 
2502 extern int __cond_resched_lock(spinlock_t *lock);
2503 
2504 #ifdef CONFIG_PREEMPT
2505 #define PREEMPT_LOCK_OFFSET	PREEMPT_OFFSET
2506 #else
2507 #define PREEMPT_LOCK_OFFSET	0
2508 #endif
2509 
2510 #define cond_resched_lock(lock) ({				\
2511 	__might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);	\
2512 	__cond_resched_lock(lock);				\
2513 })
2514 
2515 extern int __cond_resched_softirq(void);
2516 
2517 #define cond_resched_softirq() ({					\
2518 	__might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET);	\
2519 	__cond_resched_softirq();					\
2520 })
2521 
2522 /*
2523  * Does a critical section need to be broken due to another
2524  * task waiting?: (technically does not depend on CONFIG_PREEMPT,
2525  * but a general need for low latency)
2526  */
2527 static inline int spin_needbreak(spinlock_t *lock)
2528 {
2529 #ifdef CONFIG_PREEMPT
2530 	return spin_is_contended(lock);
2531 #else
2532 	return 0;
2533 #endif
2534 }
2535 
2536 /*
2537  * Thread group CPU time accounting.
2538  */
2539 void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
2540 void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
2541 
2542 static inline void thread_group_cputime_init(struct signal_struct *sig)
2543 {
2544 	spin_lock_init(&sig->cputimer.lock);
2545 }
2546 
2547 /*
2548  * Reevaluate whether the task has signals pending delivery.
2549  * Wake the task if so.
2550  * This is required every time the blocked sigset_t changes.
2551  * callers must hold sighand->siglock.
2552  */
2553 extern void recalc_sigpending_and_wake(struct task_struct *t);
2554 extern void recalc_sigpending(void);
2555 
2556 extern void signal_wake_up(struct task_struct *t, int resume_stopped);
2557 
2558 /*
2559  * Wrappers for p->thread_info->cpu access. No-op on UP.
2560  */
2561 #ifdef CONFIG_SMP
2562 
2563 static inline unsigned int task_cpu(const struct task_struct *p)
2564 {
2565 	return task_thread_info(p)->cpu;
2566 }
2567 
2568 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2569 
2570 #else
2571 
2572 static inline unsigned int task_cpu(const struct task_struct *p)
2573 {
2574 	return 0;
2575 }
2576 
2577 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2578 {
2579 }
2580 
2581 #endif /* CONFIG_SMP */
2582 
2583 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2584 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2585 
2586 extern void normalize_rt_tasks(void);
2587 
2588 #ifdef CONFIG_CGROUP_SCHED
2589 
2590 extern struct task_group root_task_group;
2591 
2592 extern struct task_group *sched_create_group(struct task_group *parent);
2593 extern void sched_destroy_group(struct task_group *tg);
2594 extern void sched_move_task(struct task_struct *tsk);
2595 #ifdef CONFIG_FAIR_GROUP_SCHED
2596 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
2597 extern unsigned long sched_group_shares(struct task_group *tg);
2598 #endif
2599 #ifdef CONFIG_RT_GROUP_SCHED
2600 extern int sched_group_set_rt_runtime(struct task_group *tg,
2601 				      long rt_runtime_us);
2602 extern long sched_group_rt_runtime(struct task_group *tg);
2603 extern int sched_group_set_rt_period(struct task_group *tg,
2604 				      long rt_period_us);
2605 extern long sched_group_rt_period(struct task_group *tg);
2606 extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk);
2607 #endif
2608 #endif
2609 
2610 extern int task_can_switch_user(struct user_struct *up,
2611 					struct task_struct *tsk);
2612 
2613 #ifdef CONFIG_TASK_XACCT
2614 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2615 {
2616 	tsk->ioac.rchar += amt;
2617 }
2618 
2619 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2620 {
2621 	tsk->ioac.wchar += amt;
2622 }
2623 
2624 static inline void inc_syscr(struct task_struct *tsk)
2625 {
2626 	tsk->ioac.syscr++;
2627 }
2628 
2629 static inline void inc_syscw(struct task_struct *tsk)
2630 {
2631 	tsk->ioac.syscw++;
2632 }
2633 #else
2634 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2635 {
2636 }
2637 
2638 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2639 {
2640 }
2641 
2642 static inline void inc_syscr(struct task_struct *tsk)
2643 {
2644 }
2645 
2646 static inline void inc_syscw(struct task_struct *tsk)
2647 {
2648 }
2649 #endif
2650 
2651 #ifndef TASK_SIZE_OF
2652 #define TASK_SIZE_OF(tsk)	TASK_SIZE
2653 #endif
2654 
2655 #ifdef CONFIG_MM_OWNER
2656 extern void mm_update_next_owner(struct mm_struct *mm);
2657 extern void mm_init_owner(struct mm_struct *mm, struct task_struct *p);
2658 #else
2659 static inline void mm_update_next_owner(struct mm_struct *mm)
2660 {
2661 }
2662 
2663 static inline void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
2664 {
2665 }
2666 #endif /* CONFIG_MM_OWNER */
2667 
2668 static inline unsigned long task_rlimit(const struct task_struct *tsk,
2669 		unsigned int limit)
2670 {
2671 	return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_cur);
2672 }
2673 
2674 static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
2675 		unsigned int limit)
2676 {
2677 	return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_max);
2678 }
2679 
2680 static inline unsigned long rlimit(unsigned int limit)
2681 {
2682 	return task_rlimit(current, limit);
2683 }
2684 
2685 static inline unsigned long rlimit_max(unsigned int limit)
2686 {
2687 	return task_rlimit_max(current, limit);
2688 }
2689 
2690 #endif /* __KERNEL__ */
2691 
2692 #endif
2693