xref: /linux/include/linux/sched.h (revision d229807f669ba3dea9f64467ee965051c4366aed)
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 #include <linux/llist.h>
94 
95 #include <asm/processor.h>
96 
97 struct exec_domain;
98 struct futex_pi_state;
99 struct robust_list_head;
100 struct bio_list;
101 struct fs_struct;
102 struct perf_event_context;
103 struct blk_plug;
104 
105 /*
106  * List of flags we want to share for kernel threads,
107  * if only because they are not used by them anyway.
108  */
109 #define CLONE_KERNEL	(CLONE_FS | CLONE_FILES | CLONE_SIGHAND)
110 
111 /*
112  * These are the constant used to fake the fixed-point load-average
113  * counting. Some notes:
114  *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
115  *    a load-average precision of 10 bits integer + 11 bits fractional
116  *  - if you want to count load-averages more often, you need more
117  *    precision, or rounding will get you. With 2-second counting freq,
118  *    the EXP_n values would be 1981, 2034 and 2043 if still using only
119  *    11 bit fractions.
120  */
121 extern unsigned long avenrun[];		/* Load averages */
122 extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
123 
124 #define FSHIFT		11		/* nr of bits of precision */
125 #define FIXED_1		(1<<FSHIFT)	/* 1.0 as fixed-point */
126 #define LOAD_FREQ	(5*HZ+1)	/* 5 sec intervals */
127 #define EXP_1		1884		/* 1/exp(5sec/1min) as fixed-point */
128 #define EXP_5		2014		/* 1/exp(5sec/5min) */
129 #define EXP_15		2037		/* 1/exp(5sec/15min) */
130 
131 #define CALC_LOAD(load,exp,n) \
132 	load *= exp; \
133 	load += n*(FIXED_1-exp); \
134 	load >>= FSHIFT;
135 
136 extern unsigned long total_forks;
137 extern int nr_threads;
138 DECLARE_PER_CPU(unsigned long, process_counts);
139 extern int nr_processes(void);
140 extern unsigned long nr_running(void);
141 extern unsigned long nr_uninterruptible(void);
142 extern unsigned long nr_iowait(void);
143 extern unsigned long nr_iowait_cpu(int cpu);
144 extern unsigned long this_cpu_load(void);
145 
146 
147 extern void calc_global_load(unsigned long ticks);
148 
149 extern unsigned long get_parent_ip(unsigned long addr);
150 
151 struct seq_file;
152 struct cfs_rq;
153 struct task_group;
154 #ifdef CONFIG_SCHED_DEBUG
155 extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
156 extern void proc_sched_set_task(struct task_struct *p);
157 extern void
158 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
159 #else
160 static inline void
161 proc_sched_show_task(struct task_struct *p, struct seq_file *m)
162 {
163 }
164 static inline void proc_sched_set_task(struct task_struct *p)
165 {
166 }
167 static inline void
168 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
169 {
170 }
171 #endif
172 
173 /*
174  * Task state bitmask. NOTE! These bits are also
175  * encoded in fs/proc/array.c: get_task_state().
176  *
177  * We have two separate sets of flags: task->state
178  * is about runnability, while task->exit_state are
179  * about the task exiting. Confusing, but this way
180  * modifying one set can't modify the other one by
181  * mistake.
182  */
183 #define TASK_RUNNING		0
184 #define TASK_INTERRUPTIBLE	1
185 #define TASK_UNINTERRUPTIBLE	2
186 #define __TASK_STOPPED		4
187 #define __TASK_TRACED		8
188 /* in tsk->exit_state */
189 #define EXIT_ZOMBIE		16
190 #define EXIT_DEAD		32
191 /* in tsk->state again */
192 #define TASK_DEAD		64
193 #define TASK_WAKEKILL		128
194 #define TASK_WAKING		256
195 #define TASK_STATE_MAX		512
196 
197 #define TASK_STATE_TO_CHAR_STR "RSDTtZXxKW"
198 
199 extern char ___assert_task_state[1 - 2*!!(
200 		sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
201 
202 /* Convenience macros for the sake of set_task_state */
203 #define TASK_KILLABLE		(TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
204 #define TASK_STOPPED		(TASK_WAKEKILL | __TASK_STOPPED)
205 #define TASK_TRACED		(TASK_WAKEKILL | __TASK_TRACED)
206 
207 /* Convenience macros for the sake of wake_up */
208 #define TASK_NORMAL		(TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
209 #define TASK_ALL		(TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
210 
211 /* get_task_state() */
212 #define TASK_REPORT		(TASK_RUNNING | TASK_INTERRUPTIBLE | \
213 				 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
214 				 __TASK_TRACED)
215 
216 #define task_is_traced(task)	((task->state & __TASK_TRACED) != 0)
217 #define task_is_stopped(task)	((task->state & __TASK_STOPPED) != 0)
218 #define task_is_dead(task)	((task)->exit_state != 0)
219 #define task_is_stopped_or_traced(task)	\
220 			((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
221 #define task_contributes_to_load(task)	\
222 				((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
223 				 (task->flags & PF_FREEZING) == 0)
224 
225 #define __set_task_state(tsk, state_value)		\
226 	do { (tsk)->state = (state_value); } while (0)
227 #define set_task_state(tsk, state_value)		\
228 	set_mb((tsk)->state, (state_value))
229 
230 /*
231  * set_current_state() includes a barrier so that the write of current->state
232  * is correctly serialised wrt the caller's subsequent test of whether to
233  * actually sleep:
234  *
235  *	set_current_state(TASK_UNINTERRUPTIBLE);
236  *	if (do_i_need_to_sleep())
237  *		schedule();
238  *
239  * If the caller does not need such serialisation then use __set_current_state()
240  */
241 #define __set_current_state(state_value)			\
242 	do { current->state = (state_value); } while (0)
243 #define set_current_state(state_value)		\
244 	set_mb(current->state, (state_value))
245 
246 /* Task command name length */
247 #define TASK_COMM_LEN 16
248 
249 #include <linux/spinlock.h>
250 
251 /*
252  * This serializes "schedule()" and also protects
253  * the run-queue from deletions/modifications (but
254  * _adding_ to the beginning of the run-queue has
255  * a separate lock).
256  */
257 extern rwlock_t tasklist_lock;
258 extern spinlock_t mmlist_lock;
259 
260 struct task_struct;
261 
262 #ifdef CONFIG_PROVE_RCU
263 extern int lockdep_tasklist_lock_is_held(void);
264 #endif /* #ifdef CONFIG_PROVE_RCU */
265 
266 extern void sched_init(void);
267 extern void sched_init_smp(void);
268 extern asmlinkage void schedule_tail(struct task_struct *prev);
269 extern void init_idle(struct task_struct *idle, int cpu);
270 extern void init_idle_bootup_task(struct task_struct *idle);
271 
272 extern int runqueue_is_locked(int cpu);
273 
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 	raw_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 0 /* BITS_PER_LONG > 32 -- currently broken: it increases power usage under light load  */
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 #define SD_OVERLAP		0x2000	/* sched_domains of this level overlap */
848 
849 enum powersavings_balance_level {
850 	POWERSAVINGS_BALANCE_NONE = 0,  /* No power saving load balance */
851 	POWERSAVINGS_BALANCE_BASIC,	/* Fill one thread/core/package
852 					 * first for long running threads
853 					 */
854 	POWERSAVINGS_BALANCE_WAKEUP,	/* Also bias task wakeups to semi-idle
855 					 * cpu package for power savings
856 					 */
857 	MAX_POWERSAVINGS_BALANCE_LEVELS
858 };
859 
860 extern int sched_mc_power_savings, sched_smt_power_savings;
861 
862 static inline int sd_balance_for_mc_power(void)
863 {
864 	if (sched_smt_power_savings)
865 		return SD_POWERSAVINGS_BALANCE;
866 
867 	if (!sched_mc_power_savings)
868 		return SD_PREFER_SIBLING;
869 
870 	return 0;
871 }
872 
873 static inline int sd_balance_for_package_power(void)
874 {
875 	if (sched_mc_power_savings | sched_smt_power_savings)
876 		return SD_POWERSAVINGS_BALANCE;
877 
878 	return SD_PREFER_SIBLING;
879 }
880 
881 extern int __weak arch_sd_sibiling_asym_packing(void);
882 
883 /*
884  * Optimise SD flags for power savings:
885  * SD_BALANCE_NEWIDLE helps aggressive task consolidation and power savings.
886  * Keep default SD flags if sched_{smt,mc}_power_saving=0
887  */
888 
889 static inline int sd_power_saving_flags(void)
890 {
891 	if (sched_mc_power_savings | sched_smt_power_savings)
892 		return SD_BALANCE_NEWIDLE;
893 
894 	return 0;
895 }
896 
897 struct sched_group_power {
898 	atomic_t ref;
899 	/*
900 	 * CPU power of this group, SCHED_LOAD_SCALE being max power for a
901 	 * single CPU.
902 	 */
903 	unsigned int power, power_orig;
904 };
905 
906 struct sched_group {
907 	struct sched_group *next;	/* Must be a circular list */
908 	atomic_t ref;
909 
910 	unsigned int group_weight;
911 	struct sched_group_power *sgp;
912 
913 	/*
914 	 * The CPUs this group covers.
915 	 *
916 	 * NOTE: this field is variable length. (Allocated dynamically
917 	 * by attaching extra space to the end of the structure,
918 	 * depending on how many CPUs the kernel has booted up with)
919 	 */
920 	unsigned long cpumask[0];
921 };
922 
923 static inline struct cpumask *sched_group_cpus(struct sched_group *sg)
924 {
925 	return to_cpumask(sg->cpumask);
926 }
927 
928 struct sched_domain_attr {
929 	int relax_domain_level;
930 };
931 
932 #define SD_ATTR_INIT	(struct sched_domain_attr) {	\
933 	.relax_domain_level = -1,			\
934 }
935 
936 extern int sched_domain_level_max;
937 
938 struct sched_domain {
939 	/* These fields must be setup */
940 	struct sched_domain *parent;	/* top domain must be null terminated */
941 	struct sched_domain *child;	/* bottom domain must be null terminated */
942 	struct sched_group *groups;	/* the balancing groups of the domain */
943 	unsigned long min_interval;	/* Minimum balance interval ms */
944 	unsigned long max_interval;	/* Maximum balance interval ms */
945 	unsigned int busy_factor;	/* less balancing by factor if busy */
946 	unsigned int imbalance_pct;	/* No balance until over watermark */
947 	unsigned int cache_nice_tries;	/* Leave cache hot tasks for # tries */
948 	unsigned int busy_idx;
949 	unsigned int idle_idx;
950 	unsigned int newidle_idx;
951 	unsigned int wake_idx;
952 	unsigned int forkexec_idx;
953 	unsigned int smt_gain;
954 	int flags;			/* See SD_* */
955 	int level;
956 
957 	/* Runtime fields. */
958 	unsigned long last_balance;	/* init to jiffies. units in jiffies */
959 	unsigned int balance_interval;	/* initialise to 1. units in ms. */
960 	unsigned int nr_balance_failed; /* initialise to 0 */
961 
962 	u64 last_update;
963 
964 #ifdef CONFIG_SCHEDSTATS
965 	/* load_balance() stats */
966 	unsigned int lb_count[CPU_MAX_IDLE_TYPES];
967 	unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
968 	unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
969 	unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
970 	unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
971 	unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
972 	unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
973 	unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
974 
975 	/* Active load balancing */
976 	unsigned int alb_count;
977 	unsigned int alb_failed;
978 	unsigned int alb_pushed;
979 
980 	/* SD_BALANCE_EXEC stats */
981 	unsigned int sbe_count;
982 	unsigned int sbe_balanced;
983 	unsigned int sbe_pushed;
984 
985 	/* SD_BALANCE_FORK stats */
986 	unsigned int sbf_count;
987 	unsigned int sbf_balanced;
988 	unsigned int sbf_pushed;
989 
990 	/* try_to_wake_up() stats */
991 	unsigned int ttwu_wake_remote;
992 	unsigned int ttwu_move_affine;
993 	unsigned int ttwu_move_balance;
994 #endif
995 #ifdef CONFIG_SCHED_DEBUG
996 	char *name;
997 #endif
998 	union {
999 		void *private;		/* used during construction */
1000 		struct rcu_head rcu;	/* used during destruction */
1001 	};
1002 
1003 	unsigned int span_weight;
1004 	/*
1005 	 * Span of all CPUs in this domain.
1006 	 *
1007 	 * NOTE: this field is variable length. (Allocated dynamically
1008 	 * by attaching extra space to the end of the structure,
1009 	 * depending on how many CPUs the kernel has booted up with)
1010 	 */
1011 	unsigned long span[0];
1012 };
1013 
1014 static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
1015 {
1016 	return to_cpumask(sd->span);
1017 }
1018 
1019 extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1020 				    struct sched_domain_attr *dattr_new);
1021 
1022 /* Allocate an array of sched domains, for partition_sched_domains(). */
1023 cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
1024 void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
1025 
1026 /* Test a flag in parent sched domain */
1027 static inline int test_sd_parent(struct sched_domain *sd, int flag)
1028 {
1029 	if (sd->parent && (sd->parent->flags & flag))
1030 		return 1;
1031 
1032 	return 0;
1033 }
1034 
1035 unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu);
1036 unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu);
1037 
1038 #else /* CONFIG_SMP */
1039 
1040 struct sched_domain_attr;
1041 
1042 static inline void
1043 partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1044 			struct sched_domain_attr *dattr_new)
1045 {
1046 }
1047 #endif	/* !CONFIG_SMP */
1048 
1049 
1050 struct io_context;			/* See blkdev.h */
1051 
1052 
1053 #ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
1054 extern void prefetch_stack(struct task_struct *t);
1055 #else
1056 static inline void prefetch_stack(struct task_struct *t) { }
1057 #endif
1058 
1059 struct audit_context;		/* See audit.c */
1060 struct mempolicy;
1061 struct pipe_inode_info;
1062 struct uts_namespace;
1063 
1064 struct rq;
1065 struct sched_domain;
1066 
1067 /*
1068  * wake flags
1069  */
1070 #define WF_SYNC		0x01		/* waker goes to sleep after wakup */
1071 #define WF_FORK		0x02		/* child wakeup after fork */
1072 #define WF_MIGRATED	0x04		/* internal use, task got migrated */
1073 
1074 #define ENQUEUE_WAKEUP		1
1075 #define ENQUEUE_HEAD		2
1076 #ifdef CONFIG_SMP
1077 #define ENQUEUE_WAKING		4	/* sched_class::task_waking was called */
1078 #else
1079 #define ENQUEUE_WAKING		0
1080 #endif
1081 
1082 #define DEQUEUE_SLEEP		1
1083 
1084 struct sched_class {
1085 	const struct sched_class *next;
1086 
1087 	void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags);
1088 	void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags);
1089 	void (*yield_task) (struct rq *rq);
1090 	bool (*yield_to_task) (struct rq *rq, struct task_struct *p, bool preempt);
1091 
1092 	void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags);
1093 
1094 	struct task_struct * (*pick_next_task) (struct rq *rq);
1095 	void (*put_prev_task) (struct rq *rq, struct task_struct *p);
1096 
1097 #ifdef CONFIG_SMP
1098 	int  (*select_task_rq)(struct task_struct *p, int sd_flag, int flags);
1099 
1100 	void (*pre_schedule) (struct rq *this_rq, struct task_struct *task);
1101 	void (*post_schedule) (struct rq *this_rq);
1102 	void (*task_waking) (struct task_struct *task);
1103 	void (*task_woken) (struct rq *this_rq, struct task_struct *task);
1104 
1105 	void (*set_cpus_allowed)(struct task_struct *p,
1106 				 const struct cpumask *newmask);
1107 
1108 	void (*rq_online)(struct rq *rq);
1109 	void (*rq_offline)(struct rq *rq);
1110 #endif
1111 
1112 	void (*set_curr_task) (struct rq *rq);
1113 	void (*task_tick) (struct rq *rq, struct task_struct *p, int queued);
1114 	void (*task_fork) (struct task_struct *p);
1115 
1116 	void (*switched_from) (struct rq *this_rq, struct task_struct *task);
1117 	void (*switched_to) (struct rq *this_rq, struct task_struct *task);
1118 	void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
1119 			     int oldprio);
1120 
1121 	unsigned int (*get_rr_interval) (struct rq *rq,
1122 					 struct task_struct *task);
1123 
1124 #ifdef CONFIG_FAIR_GROUP_SCHED
1125 	void (*task_move_group) (struct task_struct *p, int on_rq);
1126 #endif
1127 };
1128 
1129 struct load_weight {
1130 	unsigned long weight, inv_weight;
1131 };
1132 
1133 #ifdef CONFIG_SCHEDSTATS
1134 struct sched_statistics {
1135 	u64			wait_start;
1136 	u64			wait_max;
1137 	u64			wait_count;
1138 	u64			wait_sum;
1139 	u64			iowait_count;
1140 	u64			iowait_sum;
1141 
1142 	u64			sleep_start;
1143 	u64			sleep_max;
1144 	s64			sum_sleep_runtime;
1145 
1146 	u64			block_start;
1147 	u64			block_max;
1148 	u64			exec_max;
1149 	u64			slice_max;
1150 
1151 	u64			nr_migrations_cold;
1152 	u64			nr_failed_migrations_affine;
1153 	u64			nr_failed_migrations_running;
1154 	u64			nr_failed_migrations_hot;
1155 	u64			nr_forced_migrations;
1156 
1157 	u64			nr_wakeups;
1158 	u64			nr_wakeups_sync;
1159 	u64			nr_wakeups_migrate;
1160 	u64			nr_wakeups_local;
1161 	u64			nr_wakeups_remote;
1162 	u64			nr_wakeups_affine;
1163 	u64			nr_wakeups_affine_attempts;
1164 	u64			nr_wakeups_passive;
1165 	u64			nr_wakeups_idle;
1166 };
1167 #endif
1168 
1169 struct sched_entity {
1170 	struct load_weight	load;		/* for load-balancing */
1171 	struct rb_node		run_node;
1172 	struct list_head	group_node;
1173 	unsigned int		on_rq;
1174 
1175 	u64			exec_start;
1176 	u64			sum_exec_runtime;
1177 	u64			vruntime;
1178 	u64			prev_sum_exec_runtime;
1179 
1180 	u64			nr_migrations;
1181 
1182 #ifdef CONFIG_SCHEDSTATS
1183 	struct sched_statistics statistics;
1184 #endif
1185 
1186 #ifdef CONFIG_FAIR_GROUP_SCHED
1187 	struct sched_entity	*parent;
1188 	/* rq on which this entity is (to be) queued: */
1189 	struct cfs_rq		*cfs_rq;
1190 	/* rq "owned" by this entity/group: */
1191 	struct cfs_rq		*my_q;
1192 #endif
1193 };
1194 
1195 struct sched_rt_entity {
1196 	struct list_head run_list;
1197 	unsigned long timeout;
1198 	unsigned int time_slice;
1199 	int nr_cpus_allowed;
1200 
1201 	struct sched_rt_entity *back;
1202 #ifdef CONFIG_RT_GROUP_SCHED
1203 	struct sched_rt_entity	*parent;
1204 	/* rq on which this entity is (to be) queued: */
1205 	struct rt_rq		*rt_rq;
1206 	/* rq "owned" by this entity/group: */
1207 	struct rt_rq		*my_q;
1208 #endif
1209 };
1210 
1211 struct rcu_node;
1212 
1213 enum perf_event_task_context {
1214 	perf_invalid_context = -1,
1215 	perf_hw_context = 0,
1216 	perf_sw_context,
1217 	perf_nr_task_contexts,
1218 };
1219 
1220 struct task_struct {
1221 	volatile long state;	/* -1 unrunnable, 0 runnable, >0 stopped */
1222 	void *stack;
1223 	atomic_t usage;
1224 	unsigned int flags;	/* per process flags, defined below */
1225 	unsigned int ptrace;
1226 
1227 #ifdef CONFIG_SMP
1228 	struct llist_node wake_entry;
1229 	int on_cpu;
1230 #endif
1231 	int on_rq;
1232 
1233 	int prio, static_prio, normal_prio;
1234 	unsigned int rt_priority;
1235 	const struct sched_class *sched_class;
1236 	struct sched_entity se;
1237 	struct sched_rt_entity rt;
1238 
1239 #ifdef CONFIG_PREEMPT_NOTIFIERS
1240 	/* list of struct preempt_notifier: */
1241 	struct hlist_head preempt_notifiers;
1242 #endif
1243 
1244 	/*
1245 	 * fpu_counter contains the number of consecutive context switches
1246 	 * that the FPU is used. If this is over a threshold, the lazy fpu
1247 	 * saving becomes unlazy to save the trap. This is an unsigned char
1248 	 * so that after 256 times the counter wraps and the behavior turns
1249 	 * lazy again; this to deal with bursty apps that only use FPU for
1250 	 * a short time
1251 	 */
1252 	unsigned char fpu_counter;
1253 #ifdef CONFIG_BLK_DEV_IO_TRACE
1254 	unsigned int btrace_seq;
1255 #endif
1256 
1257 	unsigned int policy;
1258 	cpumask_t cpus_allowed;
1259 
1260 #ifdef CONFIG_PREEMPT_RCU
1261 	int rcu_read_lock_nesting;
1262 	char rcu_read_unlock_special;
1263 	struct list_head rcu_node_entry;
1264 #endif /* #ifdef CONFIG_PREEMPT_RCU */
1265 #ifdef CONFIG_TREE_PREEMPT_RCU
1266 	struct rcu_node *rcu_blocked_node;
1267 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
1268 #ifdef CONFIG_RCU_BOOST
1269 	struct rt_mutex *rcu_boost_mutex;
1270 #endif /* #ifdef CONFIG_RCU_BOOST */
1271 
1272 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
1273 	struct sched_info sched_info;
1274 #endif
1275 
1276 	struct list_head tasks;
1277 #ifdef CONFIG_SMP
1278 	struct plist_node pushable_tasks;
1279 #endif
1280 
1281 	struct mm_struct *mm, *active_mm;
1282 #ifdef CONFIG_COMPAT_BRK
1283 	unsigned brk_randomized:1;
1284 #endif
1285 #if defined(SPLIT_RSS_COUNTING)
1286 	struct task_rss_stat	rss_stat;
1287 #endif
1288 /* task state */
1289 	int exit_state;
1290 	int exit_code, exit_signal;
1291 	int pdeath_signal;  /*  The signal sent when the parent dies  */
1292 	unsigned int jobctl;	/* JOBCTL_*, siglock protected */
1293 	/* ??? */
1294 	unsigned int personality;
1295 	unsigned did_exec:1;
1296 	unsigned in_execve:1;	/* Tell the LSMs that the process is doing an
1297 				 * execve */
1298 	unsigned in_iowait:1;
1299 
1300 
1301 	/* Revert to default priority/policy when forking */
1302 	unsigned sched_reset_on_fork:1;
1303 	unsigned sched_contributes_to_load:1;
1304 
1305 	pid_t pid;
1306 	pid_t tgid;
1307 
1308 #ifdef CONFIG_CC_STACKPROTECTOR
1309 	/* Canary value for the -fstack-protector gcc feature */
1310 	unsigned long stack_canary;
1311 #endif
1312 
1313 	/*
1314 	 * pointers to (original) parent process, youngest child, younger sibling,
1315 	 * older sibling, respectively.  (p->father can be replaced with
1316 	 * p->real_parent->pid)
1317 	 */
1318 	struct task_struct *real_parent; /* real parent process */
1319 	struct task_struct *parent; /* recipient of SIGCHLD, wait4() reports */
1320 	/*
1321 	 * children/sibling forms the list of my natural children
1322 	 */
1323 	struct list_head children;	/* list of my children */
1324 	struct list_head sibling;	/* linkage in my parent's children list */
1325 	struct task_struct *group_leader;	/* threadgroup leader */
1326 
1327 	/*
1328 	 * ptraced is the list of tasks this task is using ptrace on.
1329 	 * This includes both natural children and PTRACE_ATTACH targets.
1330 	 * p->ptrace_entry is p's link on the p->parent->ptraced list.
1331 	 */
1332 	struct list_head ptraced;
1333 	struct list_head ptrace_entry;
1334 
1335 	/* PID/PID hash table linkage. */
1336 	struct pid_link pids[PIDTYPE_MAX];
1337 	struct list_head thread_group;
1338 
1339 	struct completion *vfork_done;		/* for vfork() */
1340 	int __user *set_child_tid;		/* CLONE_CHILD_SETTID */
1341 	int __user *clear_child_tid;		/* CLONE_CHILD_CLEARTID */
1342 
1343 	cputime_t utime, stime, utimescaled, stimescaled;
1344 	cputime_t gtime;
1345 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
1346 	cputime_t prev_utime, prev_stime;
1347 #endif
1348 	unsigned long nvcsw, nivcsw; /* context switch counts */
1349 	struct timespec start_time; 		/* monotonic time */
1350 	struct timespec real_start_time;	/* boot based time */
1351 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1352 	unsigned long min_flt, maj_flt;
1353 
1354 	struct task_cputime cputime_expires;
1355 	struct list_head cpu_timers[3];
1356 
1357 /* process credentials */
1358 	const struct cred __rcu *real_cred; /* objective and real subjective task
1359 					 * credentials (COW) */
1360 	const struct cred __rcu *cred;	/* effective (overridable) subjective task
1361 					 * credentials (COW) */
1362 	struct cred *replacement_session_keyring; /* for KEYCTL_SESSION_TO_PARENT */
1363 
1364 	char comm[TASK_COMM_LEN]; /* executable name excluding path
1365 				     - access with [gs]et_task_comm (which lock
1366 				       it with task_lock())
1367 				     - initialized normally by setup_new_exec */
1368 /* file system info */
1369 	int link_count, total_link_count;
1370 #ifdef CONFIG_SYSVIPC
1371 /* ipc stuff */
1372 	struct sysv_sem sysvsem;
1373 #endif
1374 #ifdef CONFIG_DETECT_HUNG_TASK
1375 /* hung task detection */
1376 	unsigned long last_switch_count;
1377 #endif
1378 /* CPU-specific state of this task */
1379 	struct thread_struct thread;
1380 /* filesystem information */
1381 	struct fs_struct *fs;
1382 /* open file information */
1383 	struct files_struct *files;
1384 /* namespaces */
1385 	struct nsproxy *nsproxy;
1386 /* signal handlers */
1387 	struct signal_struct *signal;
1388 	struct sighand_struct *sighand;
1389 
1390 	sigset_t blocked, real_blocked;
1391 	sigset_t saved_sigmask;	/* restored if set_restore_sigmask() was used */
1392 	struct sigpending pending;
1393 
1394 	unsigned long sas_ss_sp;
1395 	size_t sas_ss_size;
1396 	int (*notifier)(void *priv);
1397 	void *notifier_data;
1398 	sigset_t *notifier_mask;
1399 	struct audit_context *audit_context;
1400 #ifdef CONFIG_AUDITSYSCALL
1401 	uid_t loginuid;
1402 	unsigned int sessionid;
1403 #endif
1404 	seccomp_t seccomp;
1405 
1406 /* Thread group tracking */
1407    	u32 parent_exec_id;
1408    	u32 self_exec_id;
1409 /* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1410  * mempolicy */
1411 	spinlock_t alloc_lock;
1412 
1413 #ifdef CONFIG_GENERIC_HARDIRQS
1414 	/* IRQ handler threads */
1415 	struct irqaction *irqaction;
1416 #endif
1417 
1418 	/* Protection of the PI data structures: */
1419 	raw_spinlock_t pi_lock;
1420 
1421 #ifdef CONFIG_RT_MUTEXES
1422 	/* PI waiters blocked on a rt_mutex held by this task */
1423 	struct plist_head pi_waiters;
1424 	/* Deadlock detection and priority inheritance handling */
1425 	struct rt_mutex_waiter *pi_blocked_on;
1426 #endif
1427 
1428 #ifdef CONFIG_DEBUG_MUTEXES
1429 	/* mutex deadlock detection */
1430 	struct mutex_waiter *blocked_on;
1431 #endif
1432 #ifdef CONFIG_TRACE_IRQFLAGS
1433 	unsigned int irq_events;
1434 	unsigned long hardirq_enable_ip;
1435 	unsigned long hardirq_disable_ip;
1436 	unsigned int hardirq_enable_event;
1437 	unsigned int hardirq_disable_event;
1438 	int hardirqs_enabled;
1439 	int hardirq_context;
1440 	unsigned long softirq_disable_ip;
1441 	unsigned long softirq_enable_ip;
1442 	unsigned int softirq_disable_event;
1443 	unsigned int softirq_enable_event;
1444 	int softirqs_enabled;
1445 	int softirq_context;
1446 #endif
1447 #ifdef CONFIG_LOCKDEP
1448 # define MAX_LOCK_DEPTH 48UL
1449 	u64 curr_chain_key;
1450 	int lockdep_depth;
1451 	unsigned int lockdep_recursion;
1452 	struct held_lock held_locks[MAX_LOCK_DEPTH];
1453 	gfp_t lockdep_reclaim_gfp;
1454 #endif
1455 
1456 /* journalling filesystem info */
1457 	void *journal_info;
1458 
1459 /* stacked block device info */
1460 	struct bio_list *bio_list;
1461 
1462 #ifdef CONFIG_BLOCK
1463 /* stack plugging */
1464 	struct blk_plug *plug;
1465 #endif
1466 
1467 /* VM state */
1468 	struct reclaim_state *reclaim_state;
1469 
1470 	struct backing_dev_info *backing_dev_info;
1471 
1472 	struct io_context *io_context;
1473 
1474 	unsigned long ptrace_message;
1475 	siginfo_t *last_siginfo; /* For ptrace use.  */
1476 	struct task_io_accounting ioac;
1477 #if defined(CONFIG_TASK_XACCT)
1478 	u64 acct_rss_mem1;	/* accumulated rss usage */
1479 	u64 acct_vm_mem1;	/* accumulated virtual memory usage */
1480 	cputime_t acct_timexpd;	/* stime + utime since last update */
1481 #endif
1482 #ifdef CONFIG_CPUSETS
1483 	nodemask_t mems_allowed;	/* Protected by alloc_lock */
1484 	int mems_allowed_change_disable;
1485 	int cpuset_mem_spread_rotor;
1486 	int cpuset_slab_spread_rotor;
1487 #endif
1488 #ifdef CONFIG_CGROUPS
1489 	/* Control Group info protected by css_set_lock */
1490 	struct css_set __rcu *cgroups;
1491 	/* cg_list protected by css_set_lock and tsk->alloc_lock */
1492 	struct list_head cg_list;
1493 #endif
1494 #ifdef CONFIG_FUTEX
1495 	struct robust_list_head __user *robust_list;
1496 #ifdef CONFIG_COMPAT
1497 	struct compat_robust_list_head __user *compat_robust_list;
1498 #endif
1499 	struct list_head pi_state_list;
1500 	struct futex_pi_state *pi_state_cache;
1501 #endif
1502 #ifdef CONFIG_PERF_EVENTS
1503 	struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1504 	struct mutex perf_event_mutex;
1505 	struct list_head perf_event_list;
1506 #endif
1507 #ifdef CONFIG_NUMA
1508 	struct mempolicy *mempolicy;	/* Protected by alloc_lock */
1509 	short il_next;
1510 	short pref_node_fork;
1511 #endif
1512 	struct rcu_head rcu;
1513 
1514 	/*
1515 	 * cache last used pipe for splice
1516 	 */
1517 	struct pipe_inode_info *splice_pipe;
1518 #ifdef	CONFIG_TASK_DELAY_ACCT
1519 	struct task_delay_info *delays;
1520 #endif
1521 #ifdef CONFIG_FAULT_INJECTION
1522 	int make_it_fail;
1523 #endif
1524 	struct prop_local_single dirties;
1525 #ifdef CONFIG_LATENCYTOP
1526 	int latency_record_count;
1527 	struct latency_record latency_record[LT_SAVECOUNT];
1528 #endif
1529 	/*
1530 	 * time slack values; these are used to round up poll() and
1531 	 * select() etc timeout values. These are in nanoseconds.
1532 	 */
1533 	unsigned long timer_slack_ns;
1534 	unsigned long default_timer_slack_ns;
1535 
1536 	struct list_head	*scm_work_list;
1537 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1538 	/* Index of current stored address in ret_stack */
1539 	int curr_ret_stack;
1540 	/* Stack of return addresses for return function tracing */
1541 	struct ftrace_ret_stack	*ret_stack;
1542 	/* time stamp for last schedule */
1543 	unsigned long long ftrace_timestamp;
1544 	/*
1545 	 * Number of functions that haven't been traced
1546 	 * because of depth overrun.
1547 	 */
1548 	atomic_t trace_overrun;
1549 	/* Pause for the tracing */
1550 	atomic_t tracing_graph_pause;
1551 #endif
1552 #ifdef CONFIG_TRACING
1553 	/* state flags for use by tracers */
1554 	unsigned long trace;
1555 	/* bitmask and counter of trace recursion */
1556 	unsigned long trace_recursion;
1557 #endif /* CONFIG_TRACING */
1558 #ifdef CONFIG_CGROUP_MEM_RES_CTLR /* memcg uses this to do batch job */
1559 	struct memcg_batch_info {
1560 		int do_batch;	/* incremented when batch uncharge started */
1561 		struct mem_cgroup *memcg; /* target memcg of uncharge */
1562 		unsigned long nr_pages;	/* uncharged usage */
1563 		unsigned long memsw_nr_pages; /* uncharged mem+swap usage */
1564 	} memcg_batch;
1565 #endif
1566 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1567 	atomic_t ptrace_bp_refcnt;
1568 #endif
1569 };
1570 
1571 /* Future-safe accessor for struct task_struct's cpus_allowed. */
1572 #define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
1573 
1574 /*
1575  * Priority of a process goes from 0..MAX_PRIO-1, valid RT
1576  * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
1577  * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority
1578  * values are inverted: lower p->prio value means higher priority.
1579  *
1580  * The MAX_USER_RT_PRIO value allows the actual maximum
1581  * RT priority to be separate from the value exported to
1582  * user-space.  This allows kernel threads to set their
1583  * priority to a value higher than any user task. Note:
1584  * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
1585  */
1586 
1587 #define MAX_USER_RT_PRIO	100
1588 #define MAX_RT_PRIO		MAX_USER_RT_PRIO
1589 
1590 #define MAX_PRIO		(MAX_RT_PRIO + 40)
1591 #define DEFAULT_PRIO		(MAX_RT_PRIO + 20)
1592 
1593 static inline int rt_prio(int prio)
1594 {
1595 	if (unlikely(prio < MAX_RT_PRIO))
1596 		return 1;
1597 	return 0;
1598 }
1599 
1600 static inline int rt_task(struct task_struct *p)
1601 {
1602 	return rt_prio(p->prio);
1603 }
1604 
1605 static inline struct pid *task_pid(struct task_struct *task)
1606 {
1607 	return task->pids[PIDTYPE_PID].pid;
1608 }
1609 
1610 static inline struct pid *task_tgid(struct task_struct *task)
1611 {
1612 	return task->group_leader->pids[PIDTYPE_PID].pid;
1613 }
1614 
1615 /*
1616  * Without tasklist or rcu lock it is not safe to dereference
1617  * the result of task_pgrp/task_session even if task == current,
1618  * we can race with another thread doing sys_setsid/sys_setpgid.
1619  */
1620 static inline struct pid *task_pgrp(struct task_struct *task)
1621 {
1622 	return task->group_leader->pids[PIDTYPE_PGID].pid;
1623 }
1624 
1625 static inline struct pid *task_session(struct task_struct *task)
1626 {
1627 	return task->group_leader->pids[PIDTYPE_SID].pid;
1628 }
1629 
1630 struct pid_namespace;
1631 
1632 /*
1633  * the helpers to get the task's different pids as they are seen
1634  * from various namespaces
1635  *
1636  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1637  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1638  *                     current.
1639  * task_xid_nr_ns()  : id seen from the ns specified;
1640  *
1641  * set_task_vxid()   : assigns a virtual id to a task;
1642  *
1643  * see also pid_nr() etc in include/linux/pid.h
1644  */
1645 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
1646 			struct pid_namespace *ns);
1647 
1648 static inline pid_t task_pid_nr(struct task_struct *tsk)
1649 {
1650 	return tsk->pid;
1651 }
1652 
1653 static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
1654 					struct pid_namespace *ns)
1655 {
1656 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1657 }
1658 
1659 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1660 {
1661 	return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1662 }
1663 
1664 
1665 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1666 {
1667 	return tsk->tgid;
1668 }
1669 
1670 pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1671 
1672 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1673 {
1674 	return pid_vnr(task_tgid(tsk));
1675 }
1676 
1677 
1678 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
1679 					struct pid_namespace *ns)
1680 {
1681 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1682 }
1683 
1684 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1685 {
1686 	return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1687 }
1688 
1689 
1690 static inline pid_t task_session_nr_ns(struct task_struct *tsk,
1691 					struct pid_namespace *ns)
1692 {
1693 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1694 }
1695 
1696 static inline pid_t task_session_vnr(struct task_struct *tsk)
1697 {
1698 	return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1699 }
1700 
1701 /* obsolete, do not use */
1702 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1703 {
1704 	return task_pgrp_nr_ns(tsk, &init_pid_ns);
1705 }
1706 
1707 /**
1708  * pid_alive - check that a task structure is not stale
1709  * @p: Task structure to be checked.
1710  *
1711  * Test if a process is not yet dead (at most zombie state)
1712  * If pid_alive fails, then pointers within the task structure
1713  * can be stale and must not be dereferenced.
1714  */
1715 static inline int pid_alive(struct task_struct *p)
1716 {
1717 	return p->pids[PIDTYPE_PID].pid != NULL;
1718 }
1719 
1720 /**
1721  * is_global_init - check if a task structure is init
1722  * @tsk: Task structure to be checked.
1723  *
1724  * Check if a task structure is the first user space task the kernel created.
1725  */
1726 static inline int is_global_init(struct task_struct *tsk)
1727 {
1728 	return tsk->pid == 1;
1729 }
1730 
1731 /*
1732  * is_container_init:
1733  * check whether in the task is init in its own pid namespace.
1734  */
1735 extern int is_container_init(struct task_struct *tsk);
1736 
1737 extern struct pid *cad_pid;
1738 
1739 extern void free_task(struct task_struct *tsk);
1740 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
1741 
1742 extern void __put_task_struct(struct task_struct *t);
1743 
1744 static inline void put_task_struct(struct task_struct *t)
1745 {
1746 	if (atomic_dec_and_test(&t->usage))
1747 		__put_task_struct(t);
1748 }
1749 
1750 extern void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st);
1751 extern void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st);
1752 
1753 /*
1754  * Per process flags
1755  */
1756 #define PF_STARTING	0x00000002	/* being created */
1757 #define PF_EXITING	0x00000004	/* getting shut down */
1758 #define PF_EXITPIDONE	0x00000008	/* pi exit done on shut down */
1759 #define PF_VCPU		0x00000010	/* I'm a virtual CPU */
1760 #define PF_WQ_WORKER	0x00000020	/* I'm a workqueue worker */
1761 #define PF_FORKNOEXEC	0x00000040	/* forked but didn't exec */
1762 #define PF_MCE_PROCESS  0x00000080      /* process policy on mce errors */
1763 #define PF_SUPERPRIV	0x00000100	/* used super-user privileges */
1764 #define PF_DUMPCORE	0x00000200	/* dumped core */
1765 #define PF_SIGNALED	0x00000400	/* killed by a signal */
1766 #define PF_MEMALLOC	0x00000800	/* Allocating memory */
1767 #define PF_NPROC_EXCEEDED 0x00001000	/* set_user noticed that RLIMIT_NPROC was exceeded */
1768 #define PF_USED_MATH	0x00002000	/* if unset the fpu must be initialized before use */
1769 #define PF_FREEZING	0x00004000	/* freeze in progress. do not account to load */
1770 #define PF_NOFREEZE	0x00008000	/* this thread should not be frozen */
1771 #define PF_FROZEN	0x00010000	/* frozen for system suspend */
1772 #define PF_FSTRANS	0x00020000	/* inside a filesystem transaction */
1773 #define PF_KSWAPD	0x00040000	/* I am kswapd */
1774 #define PF_LESS_THROTTLE 0x00100000	/* Throttle me less: I clean memory */
1775 #define PF_KTHREAD	0x00200000	/* I am a kernel thread */
1776 #define PF_RANDOMIZE	0x00400000	/* randomize virtual address space */
1777 #define PF_SWAPWRITE	0x00800000	/* Allowed to write to swap */
1778 #define PF_SPREAD_PAGE	0x01000000	/* Spread page cache over cpuset */
1779 #define PF_SPREAD_SLAB	0x02000000	/* Spread some slab caches over cpuset */
1780 #define PF_THREAD_BOUND	0x04000000	/* Thread bound to specific cpu */
1781 #define PF_MCE_EARLY    0x08000000      /* Early kill for mce process policy */
1782 #define PF_MEMPOLICY	0x10000000	/* Non-default NUMA mempolicy */
1783 #define PF_MUTEX_TESTER	0x20000000	/* Thread belongs to the rt mutex tester */
1784 #define PF_FREEZER_SKIP	0x40000000	/* Freezer should not count it as freezable */
1785 #define PF_FREEZER_NOSIG 0x80000000	/* Freezer won't send signals to it */
1786 
1787 /*
1788  * Only the _current_ task can read/write to tsk->flags, but other
1789  * tasks can access tsk->flags in readonly mode for example
1790  * with tsk_used_math (like during threaded core dumping).
1791  * There is however an exception to this rule during ptrace
1792  * or during fork: the ptracer task is allowed to write to the
1793  * child->flags of its traced child (same goes for fork, the parent
1794  * can write to the child->flags), because we're guaranteed the
1795  * child is not running and in turn not changing child->flags
1796  * at the same time the parent does it.
1797  */
1798 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1799 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1800 #define clear_used_math() clear_stopped_child_used_math(current)
1801 #define set_used_math() set_stopped_child_used_math(current)
1802 #define conditional_stopped_child_used_math(condition, child) \
1803 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1804 #define conditional_used_math(condition) \
1805 	conditional_stopped_child_used_math(condition, current)
1806 #define copy_to_stopped_child_used_math(child) \
1807 	do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1808 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1809 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1810 #define used_math() tsk_used_math(current)
1811 
1812 /*
1813  * task->jobctl flags
1814  */
1815 #define JOBCTL_STOP_SIGMASK	0xffff	/* signr of the last group stop */
1816 
1817 #define JOBCTL_STOP_DEQUEUED_BIT 16	/* stop signal dequeued */
1818 #define JOBCTL_STOP_PENDING_BIT	17	/* task should stop for group stop */
1819 #define JOBCTL_STOP_CONSUME_BIT	18	/* consume group stop count */
1820 #define JOBCTL_TRAP_STOP_BIT	19	/* trap for STOP */
1821 #define JOBCTL_TRAP_NOTIFY_BIT	20	/* trap for NOTIFY */
1822 #define JOBCTL_TRAPPING_BIT	21	/* switching to TRACED */
1823 #define JOBCTL_LISTENING_BIT	22	/* ptracer is listening for events */
1824 
1825 #define JOBCTL_STOP_DEQUEUED	(1 << JOBCTL_STOP_DEQUEUED_BIT)
1826 #define JOBCTL_STOP_PENDING	(1 << JOBCTL_STOP_PENDING_BIT)
1827 #define JOBCTL_STOP_CONSUME	(1 << JOBCTL_STOP_CONSUME_BIT)
1828 #define JOBCTL_TRAP_STOP	(1 << JOBCTL_TRAP_STOP_BIT)
1829 #define JOBCTL_TRAP_NOTIFY	(1 << JOBCTL_TRAP_NOTIFY_BIT)
1830 #define JOBCTL_TRAPPING		(1 << JOBCTL_TRAPPING_BIT)
1831 #define JOBCTL_LISTENING	(1 << JOBCTL_LISTENING_BIT)
1832 
1833 #define JOBCTL_TRAP_MASK	(JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
1834 #define JOBCTL_PENDING_MASK	(JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)
1835 
1836 extern bool task_set_jobctl_pending(struct task_struct *task,
1837 				    unsigned int mask);
1838 extern void task_clear_jobctl_trapping(struct task_struct *task);
1839 extern void task_clear_jobctl_pending(struct task_struct *task,
1840 				      unsigned int mask);
1841 
1842 #ifdef CONFIG_PREEMPT_RCU
1843 
1844 #define RCU_READ_UNLOCK_BLOCKED (1 << 0) /* blocked while in RCU read-side. */
1845 #define RCU_READ_UNLOCK_BOOSTED (1 << 1) /* boosted while in RCU read-side. */
1846 #define RCU_READ_UNLOCK_NEED_QS (1 << 2) /* RCU core needs CPU response. */
1847 
1848 static inline void rcu_copy_process(struct task_struct *p)
1849 {
1850 	p->rcu_read_lock_nesting = 0;
1851 	p->rcu_read_unlock_special = 0;
1852 #ifdef CONFIG_TREE_PREEMPT_RCU
1853 	p->rcu_blocked_node = NULL;
1854 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
1855 #ifdef CONFIG_RCU_BOOST
1856 	p->rcu_boost_mutex = NULL;
1857 #endif /* #ifdef CONFIG_RCU_BOOST */
1858 	INIT_LIST_HEAD(&p->rcu_node_entry);
1859 }
1860 
1861 #else
1862 
1863 static inline void rcu_copy_process(struct task_struct *p)
1864 {
1865 }
1866 
1867 #endif
1868 
1869 #ifdef CONFIG_SMP
1870 extern void do_set_cpus_allowed(struct task_struct *p,
1871 			       const struct cpumask *new_mask);
1872 
1873 extern int set_cpus_allowed_ptr(struct task_struct *p,
1874 				const struct cpumask *new_mask);
1875 #else
1876 static inline void do_set_cpus_allowed(struct task_struct *p,
1877 				      const struct cpumask *new_mask)
1878 {
1879 }
1880 static inline int set_cpus_allowed_ptr(struct task_struct *p,
1881 				       const struct cpumask *new_mask)
1882 {
1883 	if (!cpumask_test_cpu(0, new_mask))
1884 		return -EINVAL;
1885 	return 0;
1886 }
1887 #endif
1888 
1889 #ifndef CONFIG_CPUMASK_OFFSTACK
1890 static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
1891 {
1892 	return set_cpus_allowed_ptr(p, &new_mask);
1893 }
1894 #endif
1895 
1896 /*
1897  * Do not use outside of architecture code which knows its limitations.
1898  *
1899  * sched_clock() has no promise of monotonicity or bounded drift between
1900  * CPUs, use (which you should not) requires disabling IRQs.
1901  *
1902  * Please use one of the three interfaces below.
1903  */
1904 extern unsigned long long notrace sched_clock(void);
1905 /*
1906  * See the comment in kernel/sched_clock.c
1907  */
1908 extern u64 cpu_clock(int cpu);
1909 extern u64 local_clock(void);
1910 extern u64 sched_clock_cpu(int cpu);
1911 
1912 
1913 extern void sched_clock_init(void);
1914 
1915 #ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
1916 static inline void sched_clock_tick(void)
1917 {
1918 }
1919 
1920 static inline void sched_clock_idle_sleep_event(void)
1921 {
1922 }
1923 
1924 static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
1925 {
1926 }
1927 #else
1928 /*
1929  * Architectures can set this to 1 if they have specified
1930  * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
1931  * but then during bootup it turns out that sched_clock()
1932  * is reliable after all:
1933  */
1934 extern int sched_clock_stable;
1935 
1936 extern void sched_clock_tick(void);
1937 extern void sched_clock_idle_sleep_event(void);
1938 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
1939 #endif
1940 
1941 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
1942 /*
1943  * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
1944  * The reason for this explicit opt-in is not to have perf penalty with
1945  * slow sched_clocks.
1946  */
1947 extern void enable_sched_clock_irqtime(void);
1948 extern void disable_sched_clock_irqtime(void);
1949 #else
1950 static inline void enable_sched_clock_irqtime(void) {}
1951 static inline void disable_sched_clock_irqtime(void) {}
1952 #endif
1953 
1954 extern unsigned long long
1955 task_sched_runtime(struct task_struct *task);
1956 
1957 /* sched_exec is called by processes performing an exec */
1958 #ifdef CONFIG_SMP
1959 extern void sched_exec(void);
1960 #else
1961 #define sched_exec()   {}
1962 #endif
1963 
1964 extern void sched_clock_idle_sleep_event(void);
1965 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
1966 
1967 #ifdef CONFIG_HOTPLUG_CPU
1968 extern void idle_task_exit(void);
1969 #else
1970 static inline void idle_task_exit(void) {}
1971 #endif
1972 
1973 #if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP)
1974 extern void wake_up_idle_cpu(int cpu);
1975 #else
1976 static inline void wake_up_idle_cpu(int cpu) { }
1977 #endif
1978 
1979 extern unsigned int sysctl_sched_latency;
1980 extern unsigned int sysctl_sched_min_granularity;
1981 extern unsigned int sysctl_sched_wakeup_granularity;
1982 extern unsigned int sysctl_sched_child_runs_first;
1983 
1984 enum sched_tunable_scaling {
1985 	SCHED_TUNABLESCALING_NONE,
1986 	SCHED_TUNABLESCALING_LOG,
1987 	SCHED_TUNABLESCALING_LINEAR,
1988 	SCHED_TUNABLESCALING_END,
1989 };
1990 extern enum sched_tunable_scaling sysctl_sched_tunable_scaling;
1991 
1992 #ifdef CONFIG_SCHED_DEBUG
1993 extern unsigned int sysctl_sched_migration_cost;
1994 extern unsigned int sysctl_sched_nr_migrate;
1995 extern unsigned int sysctl_sched_time_avg;
1996 extern unsigned int sysctl_timer_migration;
1997 extern unsigned int sysctl_sched_shares_window;
1998 
1999 int sched_proc_update_handler(struct ctl_table *table, int write,
2000 		void __user *buffer, size_t *length,
2001 		loff_t *ppos);
2002 #endif
2003 #ifdef CONFIG_SCHED_DEBUG
2004 static inline unsigned int get_sysctl_timer_migration(void)
2005 {
2006 	return sysctl_timer_migration;
2007 }
2008 #else
2009 static inline unsigned int get_sysctl_timer_migration(void)
2010 {
2011 	return 1;
2012 }
2013 #endif
2014 extern unsigned int sysctl_sched_rt_period;
2015 extern int sysctl_sched_rt_runtime;
2016 
2017 int sched_rt_handler(struct ctl_table *table, int write,
2018 		void __user *buffer, size_t *lenp,
2019 		loff_t *ppos);
2020 
2021 #ifdef CONFIG_SCHED_AUTOGROUP
2022 extern unsigned int sysctl_sched_autogroup_enabled;
2023 
2024 extern void sched_autogroup_create_attach(struct task_struct *p);
2025 extern void sched_autogroup_detach(struct task_struct *p);
2026 extern void sched_autogroup_fork(struct signal_struct *sig);
2027 extern void sched_autogroup_exit(struct signal_struct *sig);
2028 #ifdef CONFIG_PROC_FS
2029 extern void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m);
2030 extern int proc_sched_autogroup_set_nice(struct task_struct *p, int *nice);
2031 #endif
2032 #else
2033 static inline void sched_autogroup_create_attach(struct task_struct *p) { }
2034 static inline void sched_autogroup_detach(struct task_struct *p) { }
2035 static inline void sched_autogroup_fork(struct signal_struct *sig) { }
2036 static inline void sched_autogroup_exit(struct signal_struct *sig) { }
2037 #endif
2038 
2039 #ifdef CONFIG_CFS_BANDWIDTH
2040 extern unsigned int sysctl_sched_cfs_bandwidth_slice;
2041 #endif
2042 
2043 #ifdef CONFIG_RT_MUTEXES
2044 extern int rt_mutex_getprio(struct task_struct *p);
2045 extern void rt_mutex_setprio(struct task_struct *p, int prio);
2046 extern void rt_mutex_adjust_pi(struct task_struct *p);
2047 #else
2048 static inline int rt_mutex_getprio(struct task_struct *p)
2049 {
2050 	return p->normal_prio;
2051 }
2052 # define rt_mutex_adjust_pi(p)		do { } while (0)
2053 #endif
2054 
2055 extern bool yield_to(struct task_struct *p, bool preempt);
2056 extern void set_user_nice(struct task_struct *p, long nice);
2057 extern int task_prio(const struct task_struct *p);
2058 extern int task_nice(const struct task_struct *p);
2059 extern int can_nice(const struct task_struct *p, const int nice);
2060 extern int task_curr(const struct task_struct *p);
2061 extern int idle_cpu(int cpu);
2062 extern int sched_setscheduler(struct task_struct *, int,
2063 			      const struct sched_param *);
2064 extern int sched_setscheduler_nocheck(struct task_struct *, int,
2065 				      const struct sched_param *);
2066 extern struct task_struct *idle_task(int cpu);
2067 extern struct task_struct *curr_task(int cpu);
2068 extern void set_curr_task(int cpu, struct task_struct *p);
2069 
2070 void yield(void);
2071 
2072 /*
2073  * The default (Linux) execution domain.
2074  */
2075 extern struct exec_domain	default_exec_domain;
2076 
2077 union thread_union {
2078 	struct thread_info thread_info;
2079 	unsigned long stack[THREAD_SIZE/sizeof(long)];
2080 };
2081 
2082 #ifndef __HAVE_ARCH_KSTACK_END
2083 static inline int kstack_end(void *addr)
2084 {
2085 	/* Reliable end of stack detection:
2086 	 * Some APM bios versions misalign the stack
2087 	 */
2088 	return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
2089 }
2090 #endif
2091 
2092 extern union thread_union init_thread_union;
2093 extern struct task_struct init_task;
2094 
2095 extern struct   mm_struct init_mm;
2096 
2097 extern struct pid_namespace init_pid_ns;
2098 
2099 /*
2100  * find a task by one of its numerical ids
2101  *
2102  * find_task_by_pid_ns():
2103  *      finds a task by its pid in the specified namespace
2104  * find_task_by_vpid():
2105  *      finds a task by its virtual pid
2106  *
2107  * see also find_vpid() etc in include/linux/pid.h
2108  */
2109 
2110 extern struct task_struct *find_task_by_vpid(pid_t nr);
2111 extern struct task_struct *find_task_by_pid_ns(pid_t nr,
2112 		struct pid_namespace *ns);
2113 
2114 extern void __set_special_pids(struct pid *pid);
2115 
2116 /* per-UID process charging. */
2117 extern struct user_struct * alloc_uid(struct user_namespace *, uid_t);
2118 static inline struct user_struct *get_uid(struct user_struct *u)
2119 {
2120 	atomic_inc(&u->__count);
2121 	return u;
2122 }
2123 extern void free_uid(struct user_struct *);
2124 extern void release_uids(struct user_namespace *ns);
2125 
2126 #include <asm/current.h>
2127 
2128 extern void xtime_update(unsigned long ticks);
2129 
2130 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2131 extern int wake_up_process(struct task_struct *tsk);
2132 extern void wake_up_new_task(struct task_struct *tsk);
2133 #ifdef CONFIG_SMP
2134  extern void kick_process(struct task_struct *tsk);
2135 #else
2136  static inline void kick_process(struct task_struct *tsk) { }
2137 #endif
2138 extern void sched_fork(struct task_struct *p);
2139 extern void sched_dead(struct task_struct *p);
2140 
2141 extern void proc_caches_init(void);
2142 extern void flush_signals(struct task_struct *);
2143 extern void __flush_signals(struct task_struct *);
2144 extern void ignore_signals(struct task_struct *);
2145 extern void flush_signal_handlers(struct task_struct *, int force_default);
2146 extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
2147 
2148 static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
2149 {
2150 	unsigned long flags;
2151 	int ret;
2152 
2153 	spin_lock_irqsave(&tsk->sighand->siglock, flags);
2154 	ret = dequeue_signal(tsk, mask, info);
2155 	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
2156 
2157 	return ret;
2158 }
2159 
2160 extern void block_all_signals(int (*notifier)(void *priv), void *priv,
2161 			      sigset_t *mask);
2162 extern void unblock_all_signals(void);
2163 extern void release_task(struct task_struct * p);
2164 extern int send_sig_info(int, struct siginfo *, struct task_struct *);
2165 extern int force_sigsegv(int, struct task_struct *);
2166 extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2167 extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
2168 extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2169 extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *,
2170 				const struct cred *, u32);
2171 extern int kill_pgrp(struct pid *pid, int sig, int priv);
2172 extern int kill_pid(struct pid *pid, int sig, int priv);
2173 extern int kill_proc_info(int, struct siginfo *, pid_t);
2174 extern __must_check bool do_notify_parent(struct task_struct *, int);
2175 extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
2176 extern void force_sig(int, struct task_struct *);
2177 extern int send_sig(int, struct task_struct *, int);
2178 extern int zap_other_threads(struct task_struct *p);
2179 extern struct sigqueue *sigqueue_alloc(void);
2180 extern void sigqueue_free(struct sigqueue *);
2181 extern int send_sigqueue(struct sigqueue *,  struct task_struct *, int group);
2182 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
2183 extern int do_sigaltstack(const stack_t __user *, stack_t __user *, unsigned long);
2184 
2185 static inline int kill_cad_pid(int sig, int priv)
2186 {
2187 	return kill_pid(cad_pid, sig, priv);
2188 }
2189 
2190 /* These can be the second arg to send_sig_info/send_group_sig_info.  */
2191 #define SEND_SIG_NOINFO ((struct siginfo *) 0)
2192 #define SEND_SIG_PRIV	((struct siginfo *) 1)
2193 #define SEND_SIG_FORCED	((struct siginfo *) 2)
2194 
2195 /*
2196  * True if we are on the alternate signal stack.
2197  */
2198 static inline int on_sig_stack(unsigned long sp)
2199 {
2200 #ifdef CONFIG_STACK_GROWSUP
2201 	return sp >= current->sas_ss_sp &&
2202 		sp - current->sas_ss_sp < current->sas_ss_size;
2203 #else
2204 	return sp > current->sas_ss_sp &&
2205 		sp - current->sas_ss_sp <= current->sas_ss_size;
2206 #endif
2207 }
2208 
2209 static inline int sas_ss_flags(unsigned long sp)
2210 {
2211 	return (current->sas_ss_size == 0 ? SS_DISABLE
2212 		: on_sig_stack(sp) ? SS_ONSTACK : 0);
2213 }
2214 
2215 /*
2216  * Routines for handling mm_structs
2217  */
2218 extern struct mm_struct * mm_alloc(void);
2219 
2220 /* mmdrop drops the mm and the page tables */
2221 extern void __mmdrop(struct mm_struct *);
2222 static inline void mmdrop(struct mm_struct * mm)
2223 {
2224 	if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2225 		__mmdrop(mm);
2226 }
2227 
2228 /* mmput gets rid of the mappings and all user-space */
2229 extern void mmput(struct mm_struct *);
2230 /* Grab a reference to a task's mm, if it is not already going away */
2231 extern struct mm_struct *get_task_mm(struct task_struct *task);
2232 /* Remove the current tasks stale references to the old mm_struct */
2233 extern void mm_release(struct task_struct *, struct mm_struct *);
2234 /* Allocate a new mm structure and copy contents from tsk->mm */
2235 extern struct mm_struct *dup_mm(struct task_struct *tsk);
2236 
2237 extern int copy_thread(unsigned long, unsigned long, unsigned long,
2238 			struct task_struct *, struct pt_regs *);
2239 extern void flush_thread(void);
2240 extern void exit_thread(void);
2241 
2242 extern void exit_files(struct task_struct *);
2243 extern void __cleanup_sighand(struct sighand_struct *);
2244 
2245 extern void exit_itimers(struct signal_struct *);
2246 extern void flush_itimer_signals(void);
2247 
2248 extern NORET_TYPE void do_group_exit(int);
2249 
2250 extern void daemonize(const char *, ...);
2251 extern int allow_signal(int);
2252 extern int disallow_signal(int);
2253 
2254 extern int do_execve(const char *,
2255 		     const char __user * const __user *,
2256 		     const char __user * const __user *, struct pt_regs *);
2257 extern long do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *);
2258 struct task_struct *fork_idle(int);
2259 
2260 extern void set_task_comm(struct task_struct *tsk, char *from);
2261 extern char *get_task_comm(char *to, struct task_struct *tsk);
2262 
2263 #ifdef CONFIG_SMP
2264 void scheduler_ipi(void);
2265 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
2266 #else
2267 static inline void scheduler_ipi(void) { }
2268 static inline unsigned long wait_task_inactive(struct task_struct *p,
2269 					       long match_state)
2270 {
2271 	return 1;
2272 }
2273 #endif
2274 
2275 #define next_task(p) \
2276 	list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
2277 
2278 #define for_each_process(p) \
2279 	for (p = &init_task ; (p = next_task(p)) != &init_task ; )
2280 
2281 extern bool current_is_single_threaded(void);
2282 
2283 /*
2284  * Careful: do_each_thread/while_each_thread is a double loop so
2285  *          'break' will not work as expected - use goto instead.
2286  */
2287 #define do_each_thread(g, t) \
2288 	for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
2289 
2290 #define while_each_thread(g, t) \
2291 	while ((t = next_thread(t)) != g)
2292 
2293 static inline int get_nr_threads(struct task_struct *tsk)
2294 {
2295 	return tsk->signal->nr_threads;
2296 }
2297 
2298 static inline bool thread_group_leader(struct task_struct *p)
2299 {
2300 	return p->exit_signal >= 0;
2301 }
2302 
2303 /* Do to the insanities of de_thread it is possible for a process
2304  * to have the pid of the thread group leader without actually being
2305  * the thread group leader.  For iteration through the pids in proc
2306  * all we care about is that we have a task with the appropriate
2307  * pid, we don't actually care if we have the right task.
2308  */
2309 static inline int has_group_leader_pid(struct task_struct *p)
2310 {
2311 	return p->pid == p->tgid;
2312 }
2313 
2314 static inline
2315 int same_thread_group(struct task_struct *p1, struct task_struct *p2)
2316 {
2317 	return p1->tgid == p2->tgid;
2318 }
2319 
2320 static inline struct task_struct *next_thread(const struct task_struct *p)
2321 {
2322 	return list_entry_rcu(p->thread_group.next,
2323 			      struct task_struct, thread_group);
2324 }
2325 
2326 static inline int thread_group_empty(struct task_struct *p)
2327 {
2328 	return list_empty(&p->thread_group);
2329 }
2330 
2331 #define delay_group_leader(p) \
2332 		(thread_group_leader(p) && !thread_group_empty(p))
2333 
2334 /*
2335  * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
2336  * subscriptions and synchronises with wait4().  Also used in procfs.  Also
2337  * pins the final release of task.io_context.  Also protects ->cpuset and
2338  * ->cgroup.subsys[].
2339  *
2340  * Nests both inside and outside of read_lock(&tasklist_lock).
2341  * It must not be nested with write_lock_irq(&tasklist_lock),
2342  * neither inside nor outside.
2343  */
2344 static inline void task_lock(struct task_struct *p)
2345 {
2346 	spin_lock(&p->alloc_lock);
2347 }
2348 
2349 static inline void task_unlock(struct task_struct *p)
2350 {
2351 	spin_unlock(&p->alloc_lock);
2352 }
2353 
2354 extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
2355 							unsigned long *flags);
2356 
2357 #define lock_task_sighand(tsk, flags)					\
2358 ({	struct sighand_struct *__ss;					\
2359 	__cond_lock(&(tsk)->sighand->siglock,				\
2360 		    (__ss = __lock_task_sighand(tsk, flags)));		\
2361 	__ss;								\
2362 })									\
2363 
2364 static inline void unlock_task_sighand(struct task_struct *tsk,
2365 						unsigned long *flags)
2366 {
2367 	spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
2368 }
2369 
2370 /* See the declaration of threadgroup_fork_lock in signal_struct. */
2371 #ifdef CONFIG_CGROUPS
2372 static inline void threadgroup_fork_read_lock(struct task_struct *tsk)
2373 {
2374 	down_read(&tsk->signal->threadgroup_fork_lock);
2375 }
2376 static inline void threadgroup_fork_read_unlock(struct task_struct *tsk)
2377 {
2378 	up_read(&tsk->signal->threadgroup_fork_lock);
2379 }
2380 static inline void threadgroup_fork_write_lock(struct task_struct *tsk)
2381 {
2382 	down_write(&tsk->signal->threadgroup_fork_lock);
2383 }
2384 static inline void threadgroup_fork_write_unlock(struct task_struct *tsk)
2385 {
2386 	up_write(&tsk->signal->threadgroup_fork_lock);
2387 }
2388 #else
2389 static inline void threadgroup_fork_read_lock(struct task_struct *tsk) {}
2390 static inline void threadgroup_fork_read_unlock(struct task_struct *tsk) {}
2391 static inline void threadgroup_fork_write_lock(struct task_struct *tsk) {}
2392 static inline void threadgroup_fork_write_unlock(struct task_struct *tsk) {}
2393 #endif
2394 
2395 #ifndef __HAVE_THREAD_FUNCTIONS
2396 
2397 #define task_thread_info(task)	((struct thread_info *)(task)->stack)
2398 #define task_stack_page(task)	((task)->stack)
2399 
2400 static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
2401 {
2402 	*task_thread_info(p) = *task_thread_info(org);
2403 	task_thread_info(p)->task = p;
2404 }
2405 
2406 static inline unsigned long *end_of_stack(struct task_struct *p)
2407 {
2408 	return (unsigned long *)(task_thread_info(p) + 1);
2409 }
2410 
2411 #endif
2412 
2413 static inline int object_is_on_stack(void *obj)
2414 {
2415 	void *stack = task_stack_page(current);
2416 
2417 	return (obj >= stack) && (obj < (stack + THREAD_SIZE));
2418 }
2419 
2420 extern void thread_info_cache_init(void);
2421 
2422 #ifdef CONFIG_DEBUG_STACK_USAGE
2423 static inline unsigned long stack_not_used(struct task_struct *p)
2424 {
2425 	unsigned long *n = end_of_stack(p);
2426 
2427 	do { 	/* Skip over canary */
2428 		n++;
2429 	} while (!*n);
2430 
2431 	return (unsigned long)n - (unsigned long)end_of_stack(p);
2432 }
2433 #endif
2434 
2435 /* set thread flags in other task's structures
2436  * - see asm/thread_info.h for TIF_xxxx flags available
2437  */
2438 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2439 {
2440 	set_ti_thread_flag(task_thread_info(tsk), flag);
2441 }
2442 
2443 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2444 {
2445 	clear_ti_thread_flag(task_thread_info(tsk), flag);
2446 }
2447 
2448 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2449 {
2450 	return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2451 }
2452 
2453 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2454 {
2455 	return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2456 }
2457 
2458 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2459 {
2460 	return test_ti_thread_flag(task_thread_info(tsk), flag);
2461 }
2462 
2463 static inline void set_tsk_need_resched(struct task_struct *tsk)
2464 {
2465 	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2466 }
2467 
2468 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2469 {
2470 	clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2471 }
2472 
2473 static inline int test_tsk_need_resched(struct task_struct *tsk)
2474 {
2475 	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2476 }
2477 
2478 static inline int restart_syscall(void)
2479 {
2480 	set_tsk_thread_flag(current, TIF_SIGPENDING);
2481 	return -ERESTARTNOINTR;
2482 }
2483 
2484 static inline int signal_pending(struct task_struct *p)
2485 {
2486 	return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
2487 }
2488 
2489 static inline int __fatal_signal_pending(struct task_struct *p)
2490 {
2491 	return unlikely(sigismember(&p->pending.signal, SIGKILL));
2492 }
2493 
2494 static inline int fatal_signal_pending(struct task_struct *p)
2495 {
2496 	return signal_pending(p) && __fatal_signal_pending(p);
2497 }
2498 
2499 static inline int signal_pending_state(long state, struct task_struct *p)
2500 {
2501 	if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
2502 		return 0;
2503 	if (!signal_pending(p))
2504 		return 0;
2505 
2506 	return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
2507 }
2508 
2509 static inline int need_resched(void)
2510 {
2511 	return unlikely(test_thread_flag(TIF_NEED_RESCHED));
2512 }
2513 
2514 /*
2515  * cond_resched() and cond_resched_lock(): latency reduction via
2516  * explicit rescheduling in places that are safe. The return
2517  * value indicates whether a reschedule was done in fact.
2518  * cond_resched_lock() will drop the spinlock before scheduling,
2519  * cond_resched_softirq() will enable bhs before scheduling.
2520  */
2521 extern int _cond_resched(void);
2522 
2523 #define cond_resched() ({			\
2524 	__might_sleep(__FILE__, __LINE__, 0);	\
2525 	_cond_resched();			\
2526 })
2527 
2528 extern int __cond_resched_lock(spinlock_t *lock);
2529 
2530 #ifdef CONFIG_PREEMPT_COUNT
2531 #define PREEMPT_LOCK_OFFSET	PREEMPT_OFFSET
2532 #else
2533 #define PREEMPT_LOCK_OFFSET	0
2534 #endif
2535 
2536 #define cond_resched_lock(lock) ({				\
2537 	__might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);	\
2538 	__cond_resched_lock(lock);				\
2539 })
2540 
2541 extern int __cond_resched_softirq(void);
2542 
2543 #define cond_resched_softirq() ({					\
2544 	__might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET);	\
2545 	__cond_resched_softirq();					\
2546 })
2547 
2548 /*
2549  * Does a critical section need to be broken due to another
2550  * task waiting?: (technically does not depend on CONFIG_PREEMPT,
2551  * but a general need for low latency)
2552  */
2553 static inline int spin_needbreak(spinlock_t *lock)
2554 {
2555 #ifdef CONFIG_PREEMPT
2556 	return spin_is_contended(lock);
2557 #else
2558 	return 0;
2559 #endif
2560 }
2561 
2562 /*
2563  * Thread group CPU time accounting.
2564  */
2565 void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
2566 void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
2567 
2568 static inline void thread_group_cputime_init(struct signal_struct *sig)
2569 {
2570 	raw_spin_lock_init(&sig->cputimer.lock);
2571 }
2572 
2573 /*
2574  * Reevaluate whether the task has signals pending delivery.
2575  * Wake the task if so.
2576  * This is required every time the blocked sigset_t changes.
2577  * callers must hold sighand->siglock.
2578  */
2579 extern void recalc_sigpending_and_wake(struct task_struct *t);
2580 extern void recalc_sigpending(void);
2581 
2582 extern void signal_wake_up(struct task_struct *t, int resume_stopped);
2583 
2584 /*
2585  * Wrappers for p->thread_info->cpu access. No-op on UP.
2586  */
2587 #ifdef CONFIG_SMP
2588 
2589 static inline unsigned int task_cpu(const struct task_struct *p)
2590 {
2591 	return task_thread_info(p)->cpu;
2592 }
2593 
2594 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2595 
2596 #else
2597 
2598 static inline unsigned int task_cpu(const struct task_struct *p)
2599 {
2600 	return 0;
2601 }
2602 
2603 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2604 {
2605 }
2606 
2607 #endif /* CONFIG_SMP */
2608 
2609 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2610 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2611 
2612 extern void normalize_rt_tasks(void);
2613 
2614 #ifdef CONFIG_CGROUP_SCHED
2615 
2616 extern struct task_group root_task_group;
2617 
2618 extern struct task_group *sched_create_group(struct task_group *parent);
2619 extern void sched_destroy_group(struct task_group *tg);
2620 extern void sched_move_task(struct task_struct *tsk);
2621 #ifdef CONFIG_FAIR_GROUP_SCHED
2622 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
2623 extern unsigned long sched_group_shares(struct task_group *tg);
2624 #endif
2625 #ifdef CONFIG_RT_GROUP_SCHED
2626 extern int sched_group_set_rt_runtime(struct task_group *tg,
2627 				      long rt_runtime_us);
2628 extern long sched_group_rt_runtime(struct task_group *tg);
2629 extern int sched_group_set_rt_period(struct task_group *tg,
2630 				      long rt_period_us);
2631 extern long sched_group_rt_period(struct task_group *tg);
2632 extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk);
2633 #endif
2634 #endif
2635 
2636 extern int task_can_switch_user(struct user_struct *up,
2637 					struct task_struct *tsk);
2638 
2639 #ifdef CONFIG_TASK_XACCT
2640 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2641 {
2642 	tsk->ioac.rchar += amt;
2643 }
2644 
2645 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2646 {
2647 	tsk->ioac.wchar += amt;
2648 }
2649 
2650 static inline void inc_syscr(struct task_struct *tsk)
2651 {
2652 	tsk->ioac.syscr++;
2653 }
2654 
2655 static inline void inc_syscw(struct task_struct *tsk)
2656 {
2657 	tsk->ioac.syscw++;
2658 }
2659 #else
2660 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2661 {
2662 }
2663 
2664 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2665 {
2666 }
2667 
2668 static inline void inc_syscr(struct task_struct *tsk)
2669 {
2670 }
2671 
2672 static inline void inc_syscw(struct task_struct *tsk)
2673 {
2674 }
2675 #endif
2676 
2677 #ifndef TASK_SIZE_OF
2678 #define TASK_SIZE_OF(tsk)	TASK_SIZE
2679 #endif
2680 
2681 #ifdef CONFIG_MM_OWNER
2682 extern void mm_update_next_owner(struct mm_struct *mm);
2683 extern void mm_init_owner(struct mm_struct *mm, struct task_struct *p);
2684 #else
2685 static inline void mm_update_next_owner(struct mm_struct *mm)
2686 {
2687 }
2688 
2689 static inline void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
2690 {
2691 }
2692 #endif /* CONFIG_MM_OWNER */
2693 
2694 static inline unsigned long task_rlimit(const struct task_struct *tsk,
2695 		unsigned int limit)
2696 {
2697 	return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_cur);
2698 }
2699 
2700 static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
2701 		unsigned int limit)
2702 {
2703 	return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_max);
2704 }
2705 
2706 static inline unsigned long rlimit(unsigned int limit)
2707 {
2708 	return task_rlimit(current, limit);
2709 }
2710 
2711 static inline unsigned long rlimit_max(unsigned int limit)
2712 {
2713 	return task_rlimit_max(current, limit);
2714 }
2715 
2716 #endif /* __KERNEL__ */
2717 
2718 #endif
2719