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Linux/include/linux/sched.h

  1 #ifndef _LINUX_SCHED_H
  2 #define _LINUX_SCHED_H
  3 
  4 #include <uapi/linux/sched.h>
  5 
  6 #include <linux/sched/prio.h>
  7 
  8 
  9 struct sched_param {
 10         int sched_priority;
 11 };
 12 
 13 #include <asm/param.h>  /* for HZ */
 14 
 15 #include <linux/capability.h>
 16 #include <linux/threads.h>
 17 #include <linux/kernel.h>
 18 #include <linux/types.h>
 19 #include <linux/timex.h>
 20 #include <linux/jiffies.h>
 21 #include <linux/plist.h>
 22 #include <linux/rbtree.h>
 23 #include <linux/thread_info.h>
 24 #include <linux/cpumask.h>
 25 #include <linux/errno.h>
 26 #include <linux/nodemask.h>
 27 #include <linux/mm_types.h>
 28 #include <linux/preempt_mask.h>
 29 
 30 #include <asm/page.h>
 31 #include <asm/ptrace.h>
 32 #include <linux/cputime.h>
 33 
 34 #include <linux/smp.h>
 35 #include <linux/sem.h>
 36 #include <linux/shm.h>
 37 #include <linux/signal.h>
 38 #include <linux/compiler.h>
 39 #include <linux/completion.h>
 40 #include <linux/pid.h>
 41 #include <linux/percpu.h>
 42 #include <linux/topology.h>
 43 #include <linux/proportions.h>
 44 #include <linux/seccomp.h>
 45 #include <linux/rcupdate.h>
 46 #include <linux/rculist.h>
 47 #include <linux/rtmutex.h>
 48 
 49 #include <linux/time.h>
 50 #include <linux/param.h>
 51 #include <linux/resource.h>
 52 #include <linux/timer.h>
 53 #include <linux/hrtimer.h>
 54 #include <linux/task_io_accounting.h>
 55 #include <linux/latencytop.h>
 56 #include <linux/cred.h>
 57 #include <linux/llist.h>
 58 #include <linux/uidgid.h>
 59 #include <linux/gfp.h>
 60 #include <linux/magic.h>
 61 
 62 #include <asm/processor.h>
 63 
 64 #define SCHED_ATTR_SIZE_VER0    48      /* sizeof first published struct */
 65 
 66 /*
 67  * Extended scheduling parameters data structure.
 68  *
 69  * This is needed because the original struct sched_param can not be
 70  * altered without introducing ABI issues with legacy applications
 71  * (e.g., in sched_getparam()).
 72  *
 73  * However, the possibility of specifying more than just a priority for
 74  * the tasks may be useful for a wide variety of application fields, e.g.,
 75  * multimedia, streaming, automation and control, and many others.
 76  *
 77  * This variant (sched_attr) is meant at describing a so-called
 78  * sporadic time-constrained task. In such model a task is specified by:
 79  *  - the activation period or minimum instance inter-arrival time;
 80  *  - the maximum (or average, depending on the actual scheduling
 81  *    discipline) computation time of all instances, a.k.a. runtime;
 82  *  - the deadline (relative to the actual activation time) of each
 83  *    instance.
 84  * Very briefly, a periodic (sporadic) task asks for the execution of
 85  * some specific computation --which is typically called an instance--
 86  * (at most) every period. Moreover, each instance typically lasts no more
 87  * than the runtime and must be completed by time instant t equal to
 88  * the instance activation time + the deadline.
 89  *
 90  * This is reflected by the actual fields of the sched_attr structure:
 91  *
 92  *  @size               size of the structure, for fwd/bwd compat.
 93  *
 94  *  @sched_policy       task's scheduling policy
 95  *  @sched_flags        for customizing the scheduler behaviour
 96  *  @sched_nice         task's nice value      (SCHED_NORMAL/BATCH)
 97  *  @sched_priority     task's static priority (SCHED_FIFO/RR)
 98  *  @sched_deadline     representative of the task's deadline
 99  *  @sched_runtime      representative of the task's runtime
100  *  @sched_period       representative of the task's period
101  *
102  * Given this task model, there are a multiplicity of scheduling algorithms
103  * and policies, that can be used to ensure all the tasks will make their
104  * timing constraints.
105  *
106  * As of now, the SCHED_DEADLINE policy (sched_dl scheduling class) is the
107  * only user of this new interface. More information about the algorithm
108  * available in the scheduling class file or in Documentation/.
109  */
110 struct sched_attr {
111         u32 size;
112 
113         u32 sched_policy;
114         u64 sched_flags;
115 
116         /* SCHED_NORMAL, SCHED_BATCH */
117         s32 sched_nice;
118 
119         /* SCHED_FIFO, SCHED_RR */
120         u32 sched_priority;
121 
122         /* SCHED_DEADLINE */
123         u64 sched_runtime;
124         u64 sched_deadline;
125         u64 sched_period;
126 };
127 
128 struct exec_domain;
129 struct futex_pi_state;
130 struct robust_list_head;
131 struct bio_list;
132 struct fs_struct;
133 struct perf_event_context;
134 struct blk_plug;
135 struct filename;
136 
137 #define VMACACHE_BITS 2
138 #define VMACACHE_SIZE (1U << VMACACHE_BITS)
139 #define VMACACHE_MASK (VMACACHE_SIZE - 1)
140 
141 /*
142  * These are the constant used to fake the fixed-point load-average
143  * counting. Some notes:
144  *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
145  *    a load-average precision of 10 bits integer + 11 bits fractional
146  *  - if you want to count load-averages more often, you need more
147  *    precision, or rounding will get you. With 2-second counting freq,
148  *    the EXP_n values would be 1981, 2034 and 2043 if still using only
149  *    11 bit fractions.
150  */
151 extern unsigned long avenrun[];         /* Load averages */
152 extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
153 
154 #define FSHIFT          11              /* nr of bits of precision */
155 #define FIXED_1         (1<<FSHIFT)     /* 1.0 as fixed-point */
156 #define LOAD_FREQ       (5*HZ+1)        /* 5 sec intervals */
157 #define EXP_1           1884            /* 1/exp(5sec/1min) as fixed-point */
158 #define EXP_5           2014            /* 1/exp(5sec/5min) */
159 #define EXP_15          2037            /* 1/exp(5sec/15min) */
160 
161 #define CALC_LOAD(load,exp,n) \
162         load *= exp; \
163         load += n*(FIXED_1-exp); \
164         load >>= FSHIFT;
165 
166 extern unsigned long total_forks;
167 extern int nr_threads;
168 DECLARE_PER_CPU(unsigned long, process_counts);
169 extern int nr_processes(void);
170 extern unsigned long nr_running(void);
171 extern bool single_task_running(void);
172 extern unsigned long nr_iowait(void);
173 extern unsigned long nr_iowait_cpu(int cpu);
174 extern void get_iowait_load(unsigned long *nr_waiters, unsigned long *load);
175 
176 extern void calc_global_load(unsigned long ticks);
177 extern void update_cpu_load_nohz(void);
178 
179 extern unsigned long get_parent_ip(unsigned long addr);
180 
181 extern void dump_cpu_task(int cpu);
182 
183 struct seq_file;
184 struct cfs_rq;
185 struct task_group;
186 #ifdef CONFIG_SCHED_DEBUG
187 extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
188 extern void proc_sched_set_task(struct task_struct *p);
189 extern void
190 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
191 #endif
192 
193 /*
194  * Task state bitmask. NOTE! These bits are also
195  * encoded in fs/proc/array.c: get_task_state().
196  *
197  * We have two separate sets of flags: task->state
198  * is about runnability, while task->exit_state are
199  * about the task exiting. Confusing, but this way
200  * modifying one set can't modify the other one by
201  * mistake.
202  */
203 #define TASK_RUNNING            0
204 #define TASK_INTERRUPTIBLE      1
205 #define TASK_UNINTERRUPTIBLE    2
206 #define __TASK_STOPPED          4
207 #define __TASK_TRACED           8
208 /* in tsk->exit_state */
209 #define EXIT_DEAD               16
210 #define EXIT_ZOMBIE             32
211 #define EXIT_TRACE              (EXIT_ZOMBIE | EXIT_DEAD)
212 /* in tsk->state again */
213 #define TASK_DEAD               64
214 #define TASK_WAKEKILL           128
215 #define TASK_WAKING             256
216 #define TASK_PARKED             512
217 #define TASK_STATE_MAX          1024
218 
219 #define TASK_STATE_TO_CHAR_STR "RSDTtXZxKWP"
220 
221 extern char ___assert_task_state[1 - 2*!!(
222                 sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
223 
224 /* Convenience macros for the sake of set_task_state */
225 #define TASK_KILLABLE           (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
226 #define TASK_STOPPED            (TASK_WAKEKILL | __TASK_STOPPED)
227 #define TASK_TRACED             (TASK_WAKEKILL | __TASK_TRACED)
228 
229 /* Convenience macros for the sake of wake_up */
230 #define TASK_NORMAL             (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
231 #define TASK_ALL                (TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
232 
233 /* get_task_state() */
234 #define TASK_REPORT             (TASK_RUNNING | TASK_INTERRUPTIBLE | \
235                                  TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
236                                  __TASK_TRACED | EXIT_ZOMBIE | EXIT_DEAD)
237 
238 #define task_is_traced(task)    ((task->state & __TASK_TRACED) != 0)
239 #define task_is_stopped(task)   ((task->state & __TASK_STOPPED) != 0)
240 #define task_is_stopped_or_traced(task) \
241                         ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
242 #define task_contributes_to_load(task)  \
243                                 ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
244                                  (task->flags & PF_FROZEN) == 0)
245 
246 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
247 
248 #define __set_task_state(tsk, state_value)                      \
249         do {                                                    \
250                 (tsk)->task_state_change = _THIS_IP_;           \
251                 (tsk)->state = (state_value);                   \
252         } while (0)
253 #define set_task_state(tsk, state_value)                        \
254         do {                                                    \
255                 (tsk)->task_state_change = _THIS_IP_;           \
256                 set_mb((tsk)->state, (state_value));            \
257         } while (0)
258 
259 /*
260  * set_current_state() includes a barrier so that the write of current->state
261  * is correctly serialised wrt the caller's subsequent test of whether to
262  * actually sleep:
263  *
264  *      set_current_state(TASK_UNINTERRUPTIBLE);
265  *      if (do_i_need_to_sleep())
266  *              schedule();
267  *
268  * If the caller does not need such serialisation then use __set_current_state()
269  */
270 #define __set_current_state(state_value)                        \
271         do {                                                    \
272                 current->task_state_change = _THIS_IP_;         \
273                 current->state = (state_value);                 \
274         } while (0)
275 #define set_current_state(state_value)                          \
276         do {                                                    \
277                 current->task_state_change = _THIS_IP_;         \
278                 set_mb(current->state, (state_value));          \
279         } while (0)
280 
281 #else
282 
283 #define __set_task_state(tsk, state_value)              \
284         do { (tsk)->state = (state_value); } while (0)
285 #define set_task_state(tsk, state_value)                \
286         set_mb((tsk)->state, (state_value))
287 
288 /*
289  * set_current_state() includes a barrier so that the write of current->state
290  * is correctly serialised wrt the caller's subsequent test of whether to
291  * actually sleep:
292  *
293  *      set_current_state(TASK_UNINTERRUPTIBLE);
294  *      if (do_i_need_to_sleep())
295  *              schedule();
296  *
297  * If the caller does not need such serialisation then use __set_current_state()
298  */
299 #define __set_current_state(state_value)                \
300         do { current->state = (state_value); } while (0)
301 #define set_current_state(state_value)                  \
302         set_mb(current->state, (state_value))
303 
304 #endif
305 
306 /* Task command name length */
307 #define TASK_COMM_LEN 16
308 
309 #include <linux/spinlock.h>
310 
311 /*
312  * This serializes "schedule()" and also protects
313  * the run-queue from deletions/modifications (but
314  * _adding_ to the beginning of the run-queue has
315  * a separate lock).
316  */
317 extern rwlock_t tasklist_lock;
318 extern spinlock_t mmlist_lock;
319 
320 struct task_struct;
321 
322 #ifdef CONFIG_PROVE_RCU
323 extern int lockdep_tasklist_lock_is_held(void);
324 #endif /* #ifdef CONFIG_PROVE_RCU */
325 
326 extern void sched_init(void);
327 extern void sched_init_smp(void);
328 extern asmlinkage void schedule_tail(struct task_struct *prev);
329 extern void init_idle(struct task_struct *idle, int cpu);
330 extern void init_idle_bootup_task(struct task_struct *idle);
331 
332 extern int runqueue_is_locked(int cpu);
333 
334 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
335 extern void nohz_balance_enter_idle(int cpu);
336 extern void set_cpu_sd_state_idle(void);
337 extern int get_nohz_timer_target(int pinned);
338 #else
339 static inline void nohz_balance_enter_idle(int cpu) { }
340 static inline void set_cpu_sd_state_idle(void) { }
341 static inline int get_nohz_timer_target(int pinned)
342 {
343         return smp_processor_id();
344 }
345 #endif
346 
347 /*
348  * Only dump TASK_* tasks. (0 for all tasks)
349  */
350 extern void show_state_filter(unsigned long state_filter);
351 
352 static inline void show_state(void)
353 {
354         show_state_filter(0);
355 }
356 
357 extern void show_regs(struct pt_regs *);
358 
359 /*
360  * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
361  * task), SP is the stack pointer of the first frame that should be shown in the back
362  * trace (or NULL if the entire call-chain of the task should be shown).
363  */
364 extern void show_stack(struct task_struct *task, unsigned long *sp);
365 
366 void io_schedule(void);
367 long io_schedule_timeout(long timeout);
368 
369 extern void cpu_init (void);
370 extern void trap_init(void);
371 extern void update_process_times(int user);
372 extern void scheduler_tick(void);
373 
374 extern void sched_show_task(struct task_struct *p);
375 
376 #ifdef CONFIG_LOCKUP_DETECTOR
377 extern void touch_softlockup_watchdog(void);
378 extern void touch_softlockup_watchdog_sync(void);
379 extern void touch_all_softlockup_watchdogs(void);
380 extern int proc_dowatchdog_thresh(struct ctl_table *table, int write,
381                                   void __user *buffer,
382                                   size_t *lenp, loff_t *ppos);
383 extern unsigned int  softlockup_panic;
384 void lockup_detector_init(void);
385 #else
386 static inline void touch_softlockup_watchdog(void)
387 {
388 }
389 static inline void touch_softlockup_watchdog_sync(void)
390 {
391 }
392 static inline void touch_all_softlockup_watchdogs(void)
393 {
394 }
395 static inline void lockup_detector_init(void)
396 {
397 }
398 #endif
399 
400 #ifdef CONFIG_DETECT_HUNG_TASK
401 void reset_hung_task_detector(void);
402 #else
403 static inline void reset_hung_task_detector(void)
404 {
405 }
406 #endif
407 
408 /* Attach to any functions which should be ignored in wchan output. */
409 #define __sched         __attribute__((__section__(".sched.text")))
410 
411 /* Linker adds these: start and end of __sched functions */
412 extern char __sched_text_start[], __sched_text_end[];
413 
414 /* Is this address in the __sched functions? */
415 extern int in_sched_functions(unsigned long addr);
416 
417 #define MAX_SCHEDULE_TIMEOUT    LONG_MAX
418 extern signed long schedule_timeout(signed long timeout);
419 extern signed long schedule_timeout_interruptible(signed long timeout);
420 extern signed long schedule_timeout_killable(signed long timeout);
421 extern signed long schedule_timeout_uninterruptible(signed long timeout);
422 asmlinkage void schedule(void);
423 extern void schedule_preempt_disabled(void);
424 
425 struct nsproxy;
426 struct user_namespace;
427 
428 #ifdef CONFIG_MMU
429 extern void arch_pick_mmap_layout(struct mm_struct *mm);
430 extern unsigned long
431 arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
432                        unsigned long, unsigned long);
433 extern unsigned long
434 arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
435                           unsigned long len, unsigned long pgoff,
436                           unsigned long flags);
437 #else
438 static inline void arch_pick_mmap_layout(struct mm_struct *mm) {}
439 #endif
440 
441 #define SUID_DUMP_DISABLE       0       /* No setuid dumping */
442 #define SUID_DUMP_USER          1       /* Dump as user of process */
443 #define SUID_DUMP_ROOT          2       /* Dump as root */
444 
445 /* mm flags */
446 
447 /* for SUID_DUMP_* above */
448 #define MMF_DUMPABLE_BITS 2
449 #define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
450 
451 extern void set_dumpable(struct mm_struct *mm, int value);
452 /*
453  * This returns the actual value of the suid_dumpable flag. For things
454  * that are using this for checking for privilege transitions, it must
455  * test against SUID_DUMP_USER rather than treating it as a boolean
456  * value.
457  */
458 static inline int __get_dumpable(unsigned long mm_flags)
459 {
460         return mm_flags & MMF_DUMPABLE_MASK;
461 }
462 
463 static inline int get_dumpable(struct mm_struct *mm)
464 {
465         return __get_dumpable(mm->flags);
466 }
467 
468 /* coredump filter bits */
469 #define MMF_DUMP_ANON_PRIVATE   2
470 #define MMF_DUMP_ANON_SHARED    3
471 #define MMF_DUMP_MAPPED_PRIVATE 4
472 #define MMF_DUMP_MAPPED_SHARED  5
473 #define MMF_DUMP_ELF_HEADERS    6
474 #define MMF_DUMP_HUGETLB_PRIVATE 7
475 #define MMF_DUMP_HUGETLB_SHARED  8
476 
477 #define MMF_DUMP_FILTER_SHIFT   MMF_DUMPABLE_BITS
478 #define MMF_DUMP_FILTER_BITS    7
479 #define MMF_DUMP_FILTER_MASK \
480         (((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
481 #define MMF_DUMP_FILTER_DEFAULT \
482         ((1 << MMF_DUMP_ANON_PRIVATE) | (1 << MMF_DUMP_ANON_SHARED) |\
483          (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
484 
485 #ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
486 # define MMF_DUMP_MASK_DEFAULT_ELF      (1 << MMF_DUMP_ELF_HEADERS)
487 #else
488 # define MMF_DUMP_MASK_DEFAULT_ELF      0
489 #endif
490                                         /* leave room for more dump flags */
491 #define MMF_VM_MERGEABLE        16      /* KSM may merge identical pages */
492 #define MMF_VM_HUGEPAGE         17      /* set when VM_HUGEPAGE is set on vma */
493 #define MMF_EXE_FILE_CHANGED    18      /* see prctl_set_mm_exe_file() */
494 
495 #define MMF_HAS_UPROBES         19      /* has uprobes */
496 #define MMF_RECALC_UPROBES      20      /* MMF_HAS_UPROBES can be wrong */
497 
498 #define MMF_INIT_MASK           (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
499 
500 struct sighand_struct {
501         atomic_t                count;
502         struct k_sigaction      action[_NSIG];
503         spinlock_t              siglock;
504         wait_queue_head_t       signalfd_wqh;
505 };
506 
507 struct pacct_struct {
508         int                     ac_flag;
509         long                    ac_exitcode;
510         unsigned long           ac_mem;
511         cputime_t               ac_utime, ac_stime;
512         unsigned long           ac_minflt, ac_majflt;
513 };
514 
515 struct cpu_itimer {
516         cputime_t expires;
517         cputime_t incr;
518         u32 error;
519         u32 incr_error;
520 };
521 
522 /**
523  * struct cputime - snaphsot of system and user cputime
524  * @utime: time spent in user mode
525  * @stime: time spent in system mode
526  *
527  * Gathers a generic snapshot of user and system time.
528  */
529 struct cputime {
530         cputime_t utime;
531         cputime_t stime;
532 };
533 
534 /**
535  * struct task_cputime - collected CPU time counts
536  * @utime:              time spent in user mode, in &cputime_t units
537  * @stime:              time spent in kernel mode, in &cputime_t units
538  * @sum_exec_runtime:   total time spent on the CPU, in nanoseconds
539  *
540  * This is an extension of struct cputime that includes the total runtime
541  * spent by the task from the scheduler point of view.
542  *
543  * As a result, this structure groups together three kinds of CPU time
544  * that are tracked for threads and thread groups.  Most things considering
545  * CPU time want to group these counts together and treat all three
546  * of them in parallel.
547  */
548 struct task_cputime {
549         cputime_t utime;
550         cputime_t stime;
551         unsigned long long sum_exec_runtime;
552 };
553 /* Alternate field names when used to cache expirations. */
554 #define prof_exp        stime
555 #define virt_exp        utime
556 #define sched_exp       sum_exec_runtime
557 
558 #define INIT_CPUTIME    \
559         (struct task_cputime) {                                 \
560                 .utime = 0,                                     \
561                 .stime = 0,                                     \
562                 .sum_exec_runtime = 0,                          \
563         }
564 
565 #ifdef CONFIG_PREEMPT_COUNT
566 #define PREEMPT_DISABLED        (1 + PREEMPT_ENABLED)
567 #else
568 #define PREEMPT_DISABLED        PREEMPT_ENABLED
569 #endif
570 
571 /*
572  * Disable preemption until the scheduler is running.
573  * Reset by start_kernel()->sched_init()->init_idle().
574  *
575  * We include PREEMPT_ACTIVE to avoid cond_resched() from working
576  * before the scheduler is active -- see should_resched().
577  */
578 #define INIT_PREEMPT_COUNT      (PREEMPT_DISABLED + PREEMPT_ACTIVE)
579 
580 /**
581  * struct thread_group_cputimer - thread group interval timer counts
582  * @cputime:            thread group interval timers.
583  * @running:            non-zero when there are timers running and
584  *                      @cputime receives updates.
585  * @lock:               lock for fields in this struct.
586  *
587  * This structure contains the version of task_cputime, above, that is
588  * used for thread group CPU timer calculations.
589  */
590 struct thread_group_cputimer {
591         struct task_cputime cputime;
592         int running;
593         raw_spinlock_t lock;
594 };
595 
596 #include <linux/rwsem.h>
597 struct autogroup;
598 
599 /*
600  * NOTE! "signal_struct" does not have its own
601  * locking, because a shared signal_struct always
602  * implies a shared sighand_struct, so locking
603  * sighand_struct is always a proper superset of
604  * the locking of signal_struct.
605  */
606 struct signal_struct {
607         atomic_t                sigcnt;
608         atomic_t                live;
609         int                     nr_threads;
610         struct list_head        thread_head;
611 
612         wait_queue_head_t       wait_chldexit;  /* for wait4() */
613 
614         /* current thread group signal load-balancing target: */
615         struct task_struct      *curr_target;
616 
617         /* shared signal handling: */
618         struct sigpending       shared_pending;
619 
620         /* thread group exit support */
621         int                     group_exit_code;
622         /* overloaded:
623          * - notify group_exit_task when ->count is equal to notify_count
624          * - everyone except group_exit_task is stopped during signal delivery
625          *   of fatal signals, group_exit_task processes the signal.
626          */
627         int                     notify_count;
628         struct task_struct      *group_exit_task;
629 
630         /* thread group stop support, overloads group_exit_code too */
631         int                     group_stop_count;
632         unsigned int            flags; /* see SIGNAL_* flags below */
633 
634         /*
635          * PR_SET_CHILD_SUBREAPER marks a process, like a service
636          * manager, to re-parent orphan (double-forking) child processes
637          * to this process instead of 'init'. The service manager is
638          * able to receive SIGCHLD signals and is able to investigate
639          * the process until it calls wait(). All children of this
640          * process will inherit a flag if they should look for a
641          * child_subreaper process at exit.
642          */
643         unsigned int            is_child_subreaper:1;
644         unsigned int            has_child_subreaper:1;
645 
646         /* POSIX.1b Interval Timers */
647         int                     posix_timer_id;
648         struct list_head        posix_timers;
649 
650         /* ITIMER_REAL timer for the process */
651         struct hrtimer real_timer;
652         struct pid *leader_pid;
653         ktime_t it_real_incr;
654 
655         /*
656          * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
657          * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
658          * values are defined to 0 and 1 respectively
659          */
660         struct cpu_itimer it[2];
661 
662         /*
663          * Thread group totals for process CPU timers.
664          * See thread_group_cputimer(), et al, for details.
665          */
666         struct thread_group_cputimer cputimer;
667 
668         /* Earliest-expiration cache. */
669         struct task_cputime cputime_expires;
670 
671         struct list_head cpu_timers[3];
672 
673         struct pid *tty_old_pgrp;
674 
675         /* boolean value for session group leader */
676         int leader;
677 
678         struct tty_struct *tty; /* NULL if no tty */
679 
680 #ifdef CONFIG_SCHED_AUTOGROUP
681         struct autogroup *autogroup;
682 #endif
683         /*
684          * Cumulative resource counters for dead threads in the group,
685          * and for reaped dead child processes forked by this group.
686          * Live threads maintain their own counters and add to these
687          * in __exit_signal, except for the group leader.
688          */
689         seqlock_t stats_lock;
690         cputime_t utime, stime, cutime, cstime;
691         cputime_t gtime;
692         cputime_t cgtime;
693 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
694         struct cputime prev_cputime;
695 #endif
696         unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
697         unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
698         unsigned long inblock, oublock, cinblock, coublock;
699         unsigned long maxrss, cmaxrss;
700         struct task_io_accounting ioac;
701 
702         /*
703          * Cumulative ns of schedule CPU time fo dead threads in the
704          * group, not including a zombie group leader, (This only differs
705          * from jiffies_to_ns(utime + stime) if sched_clock uses something
706          * other than jiffies.)
707          */
708         unsigned long long sum_sched_runtime;
709 
710         /*
711          * We don't bother to synchronize most readers of this at all,
712          * because there is no reader checking a limit that actually needs
713          * to get both rlim_cur and rlim_max atomically, and either one
714          * alone is a single word that can safely be read normally.
715          * getrlimit/setrlimit use task_lock(current->group_leader) to
716          * protect this instead of the siglock, because they really
717          * have no need to disable irqs.
718          */
719         struct rlimit rlim[RLIM_NLIMITS];
720 
721 #ifdef CONFIG_BSD_PROCESS_ACCT
722         struct pacct_struct pacct;      /* per-process accounting information */
723 #endif
724 #ifdef CONFIG_TASKSTATS
725         struct taskstats *stats;
726 #endif
727 #ifdef CONFIG_AUDIT
728         unsigned audit_tty;
729         unsigned audit_tty_log_passwd;
730         struct tty_audit_buf *tty_audit_buf;
731 #endif
732 #ifdef CONFIG_CGROUPS
733         /*
734          * group_rwsem prevents new tasks from entering the threadgroup and
735          * member tasks from exiting,a more specifically, setting of
736          * PF_EXITING.  fork and exit paths are protected with this rwsem
737          * using threadgroup_change_begin/end().  Users which require
738          * threadgroup to remain stable should use threadgroup_[un]lock()
739          * which also takes care of exec path.  Currently, cgroup is the
740          * only user.
741          */
742         struct rw_semaphore group_rwsem;
743 #endif
744 
745         oom_flags_t oom_flags;
746         short oom_score_adj;            /* OOM kill score adjustment */
747         short oom_score_adj_min;        /* OOM kill score adjustment min value.
748                                          * Only settable by CAP_SYS_RESOURCE. */
749 
750         struct mutex cred_guard_mutex;  /* guard against foreign influences on
751                                          * credential calculations
752                                          * (notably. ptrace) */
753 };
754 
755 /*
756  * Bits in flags field of signal_struct.
757  */
758 #define SIGNAL_STOP_STOPPED     0x00000001 /* job control stop in effect */
759 #define SIGNAL_STOP_CONTINUED   0x00000002 /* SIGCONT since WCONTINUED reap */
760 #define SIGNAL_GROUP_EXIT       0x00000004 /* group exit in progress */
761 #define SIGNAL_GROUP_COREDUMP   0x00000008 /* coredump in progress */
762 /*
763  * Pending notifications to parent.
764  */
765 #define SIGNAL_CLD_STOPPED      0x00000010
766 #define SIGNAL_CLD_CONTINUED    0x00000020
767 #define SIGNAL_CLD_MASK         (SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
768 
769 #define SIGNAL_UNKILLABLE       0x00000040 /* for init: ignore fatal signals */
770 
771 /* If true, all threads except ->group_exit_task have pending SIGKILL */
772 static inline int signal_group_exit(const struct signal_struct *sig)
773 {
774         return  (sig->flags & SIGNAL_GROUP_EXIT) ||
775                 (sig->group_exit_task != NULL);
776 }
777 
778 /*
779  * Some day this will be a full-fledged user tracking system..
780  */
781 struct user_struct {
782         atomic_t __count;       /* reference count */
783         atomic_t processes;     /* How many processes does this user have? */
784         atomic_t sigpending;    /* How many pending signals does this user have? */
785 #ifdef CONFIG_INOTIFY_USER
786         atomic_t inotify_watches; /* How many inotify watches does this user have? */
787         atomic_t inotify_devs;  /* How many inotify devs does this user have opened? */
788 #endif
789 #ifdef CONFIG_FANOTIFY
790         atomic_t fanotify_listeners;
791 #endif
792 #ifdef CONFIG_EPOLL
793         atomic_long_t epoll_watches; /* The number of file descriptors currently watched */
794 #endif
795 #ifdef CONFIG_POSIX_MQUEUE
796         /* protected by mq_lock */
797         unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */
798 #endif
799         unsigned long locked_shm; /* How many pages of mlocked shm ? */
800 
801 #ifdef CONFIG_KEYS
802         struct key *uid_keyring;        /* UID specific keyring */
803         struct key *session_keyring;    /* UID's default session keyring */
804 #endif
805 
806         /* Hash table maintenance information */
807         struct hlist_node uidhash_node;
808         kuid_t uid;
809 
810 #ifdef CONFIG_PERF_EVENTS
811         atomic_long_t locked_vm;
812 #endif
813 };
814 
815 extern int uids_sysfs_init(void);
816 
817 extern struct user_struct *find_user(kuid_t);
818 
819 extern struct user_struct root_user;
820 #define INIT_USER (&root_user)
821 
822 
823 struct backing_dev_info;
824 struct reclaim_state;
825 
826 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
827 struct sched_info {
828         /* cumulative counters */
829         unsigned long pcount;         /* # of times run on this cpu */
830         unsigned long long run_delay; /* time spent waiting on a runqueue */
831 
832         /* timestamps */
833         unsigned long long last_arrival,/* when we last ran on a cpu */
834                            last_queued; /* when we were last queued to run */
835 };
836 #endif /* defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) */
837 
838 #ifdef CONFIG_TASK_DELAY_ACCT
839 struct task_delay_info {
840         spinlock_t      lock;
841         unsigned int    flags;  /* Private per-task flags */
842 
843         /* For each stat XXX, add following, aligned appropriately
844          *
845          * struct timespec XXX_start, XXX_end;
846          * u64 XXX_delay;
847          * u32 XXX_count;
848          *
849          * Atomicity of updates to XXX_delay, XXX_count protected by
850          * single lock above (split into XXX_lock if contention is an issue).
851          */
852 
853         /*
854          * XXX_count is incremented on every XXX operation, the delay
855          * associated with the operation is added to XXX_delay.
856          * XXX_delay contains the accumulated delay time in nanoseconds.
857          */
858         u64 blkio_start;        /* Shared by blkio, swapin */
859         u64 blkio_delay;        /* wait for sync block io completion */
860         u64 swapin_delay;       /* wait for swapin block io completion */
861         u32 blkio_count;        /* total count of the number of sync block */
862                                 /* io operations performed */
863         u32 swapin_count;       /* total count of the number of swapin block */
864                                 /* io operations performed */
865 
866         u64 freepages_start;
867         u64 freepages_delay;    /* wait for memory reclaim */
868         u32 freepages_count;    /* total count of memory reclaim */
869 };
870 #endif  /* CONFIG_TASK_DELAY_ACCT */
871 
872 static inline int sched_info_on(void)
873 {
874 #ifdef CONFIG_SCHEDSTATS
875         return 1;
876 #elif defined(CONFIG_TASK_DELAY_ACCT)
877         extern int delayacct_on;
878         return delayacct_on;
879 #else
880         return 0;
881 #endif
882 }
883 
884 enum cpu_idle_type {
885         CPU_IDLE,
886         CPU_NOT_IDLE,
887         CPU_NEWLY_IDLE,
888         CPU_MAX_IDLE_TYPES
889 };
890 
891 /*
892  * Increase resolution of cpu_capacity calculations
893  */
894 #define SCHED_CAPACITY_SHIFT    10
895 #define SCHED_CAPACITY_SCALE    (1L << SCHED_CAPACITY_SHIFT)
896 
897 /*
898  * sched-domains (multiprocessor balancing) declarations:
899  */
900 #ifdef CONFIG_SMP
901 #define SD_LOAD_BALANCE         0x0001  /* Do load balancing on this domain. */
902 #define SD_BALANCE_NEWIDLE      0x0002  /* Balance when about to become idle */
903 #define SD_BALANCE_EXEC         0x0004  /* Balance on exec */
904 #define SD_BALANCE_FORK         0x0008  /* Balance on fork, clone */
905 #define SD_BALANCE_WAKE         0x0010  /* Balance on wakeup */
906 #define SD_WAKE_AFFINE          0x0020  /* Wake task to waking CPU */
907 #define SD_SHARE_CPUCAPACITY    0x0080  /* Domain members share cpu power */
908 #define SD_SHARE_POWERDOMAIN    0x0100  /* Domain members share power domain */
909 #define SD_SHARE_PKG_RESOURCES  0x0200  /* Domain members share cpu pkg resources */
910 #define SD_SERIALIZE            0x0400  /* Only a single load balancing instance */
911 #define SD_ASYM_PACKING         0x0800  /* Place busy groups earlier in the domain */
912 #define SD_PREFER_SIBLING       0x1000  /* Prefer to place tasks in a sibling domain */
913 #define SD_OVERLAP              0x2000  /* sched_domains of this level overlap */
914 #define SD_NUMA                 0x4000  /* cross-node balancing */
915 
916 #ifdef CONFIG_SCHED_SMT
917 static inline int cpu_smt_flags(void)
918 {
919         return SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
920 }
921 #endif
922 
923 #ifdef CONFIG_SCHED_MC
924 static inline int cpu_core_flags(void)
925 {
926         return SD_SHARE_PKG_RESOURCES;
927 }
928 #endif
929 
930 #ifdef CONFIG_NUMA
931 static inline int cpu_numa_flags(void)
932 {
933         return SD_NUMA;
934 }
935 #endif
936 
937 struct sched_domain_attr {
938         int relax_domain_level;
939 };
940 
941 #define SD_ATTR_INIT    (struct sched_domain_attr) {    \
942         .relax_domain_level = -1,                       \
943 }
944 
945 extern int sched_domain_level_max;
946 
947 struct sched_group;
948 
949 struct sched_domain {
950         /* These fields must be setup */
951         struct sched_domain *parent;    /* top domain must be null terminated */
952         struct sched_domain *child;     /* bottom domain must be null terminated */
953         struct sched_group *groups;     /* the balancing groups of the domain */
954         unsigned long min_interval;     /* Minimum balance interval ms */
955         unsigned long max_interval;     /* Maximum balance interval ms */
956         unsigned int busy_factor;       /* less balancing by factor if busy */
957         unsigned int imbalance_pct;     /* No balance until over watermark */
958         unsigned int cache_nice_tries;  /* Leave cache hot tasks for # tries */
959         unsigned int busy_idx;
960         unsigned int idle_idx;
961         unsigned int newidle_idx;
962         unsigned int wake_idx;
963         unsigned int forkexec_idx;
964         unsigned int smt_gain;
965 
966         int nohz_idle;                  /* NOHZ IDLE status */
967         int flags;                      /* See SD_* */
968         int level;
969 
970         /* Runtime fields. */
971         unsigned long last_balance;     /* init to jiffies. units in jiffies */
972         unsigned int balance_interval;  /* initialise to 1. units in ms. */
973         unsigned int nr_balance_failed; /* initialise to 0 */
974 
975         /* idle_balance() stats */
976         u64 max_newidle_lb_cost;
977         unsigned long next_decay_max_lb_cost;
978 
979 #ifdef CONFIG_SCHEDSTATS
980         /* load_balance() stats */
981         unsigned int lb_count[CPU_MAX_IDLE_TYPES];
982         unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
983         unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
984         unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
985         unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
986         unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
987         unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
988         unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
989 
990         /* Active load balancing */
991         unsigned int alb_count;
992         unsigned int alb_failed;
993         unsigned int alb_pushed;
994 
995         /* SD_BALANCE_EXEC stats */
996         unsigned int sbe_count;
997         unsigned int sbe_balanced;
998         unsigned int sbe_pushed;
999 
1000         /* SD_BALANCE_FORK stats */
1001         unsigned int sbf_count;
1002         unsigned int sbf_balanced;
1003         unsigned int sbf_pushed;
1004 
1005         /* try_to_wake_up() stats */
1006         unsigned int ttwu_wake_remote;
1007         unsigned int ttwu_move_affine;
1008         unsigned int ttwu_move_balance;
1009 #endif
1010 #ifdef CONFIG_SCHED_DEBUG
1011         char *name;
1012 #endif
1013         union {
1014                 void *private;          /* used during construction */
1015                 struct rcu_head rcu;    /* used during destruction */
1016         };
1017 
1018         unsigned int span_weight;
1019         /*
1020          * Span of all CPUs in this domain.
1021          *
1022          * NOTE: this field is variable length. (Allocated dynamically
1023          * by attaching extra space to the end of the structure,
1024          * depending on how many CPUs the kernel has booted up with)
1025          */
1026         unsigned long span[0];
1027 };
1028 
1029 static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
1030 {
1031         return to_cpumask(sd->span);
1032 }
1033 
1034 extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1035                                     struct sched_domain_attr *dattr_new);
1036 
1037 /* Allocate an array of sched domains, for partition_sched_domains(). */
1038 cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
1039 void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
1040 
1041 bool cpus_share_cache(int this_cpu, int that_cpu);
1042 
1043 typedef const struct cpumask *(*sched_domain_mask_f)(int cpu);
1044 typedef int (*sched_domain_flags_f)(void);
1045 
1046 #define SDTL_OVERLAP    0x01
1047 
1048 struct sd_data {
1049         struct sched_domain **__percpu sd;
1050         struct sched_group **__percpu sg;
1051         struct sched_group_capacity **__percpu sgc;
1052 };
1053 
1054 struct sched_domain_topology_level {
1055         sched_domain_mask_f mask;
1056         sched_domain_flags_f sd_flags;
1057         int                 flags;
1058         int                 numa_level;
1059         struct sd_data      data;
1060 #ifdef CONFIG_SCHED_DEBUG
1061         char                *name;
1062 #endif
1063 };
1064 
1065 extern struct sched_domain_topology_level *sched_domain_topology;
1066 
1067 extern void set_sched_topology(struct sched_domain_topology_level *tl);
1068 extern void wake_up_if_idle(int cpu);
1069 
1070 #ifdef CONFIG_SCHED_DEBUG
1071 # define SD_INIT_NAME(type)             .name = #type
1072 #else
1073 # define SD_INIT_NAME(type)
1074 #endif
1075 
1076 #else /* CONFIG_SMP */
1077 
1078 struct sched_domain_attr;
1079 
1080 static inline void
1081 partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1082                         struct sched_domain_attr *dattr_new)
1083 {
1084 }
1085 
1086 static inline bool cpus_share_cache(int this_cpu, int that_cpu)
1087 {
1088         return true;
1089 }
1090 
1091 #endif  /* !CONFIG_SMP */
1092 
1093 
1094 struct io_context;                      /* See blkdev.h */
1095 
1096 
1097 #ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
1098 extern void prefetch_stack(struct task_struct *t);
1099 #else
1100 static inline void prefetch_stack(struct task_struct *t) { }
1101 #endif
1102 
1103 struct audit_context;           /* See audit.c */
1104 struct mempolicy;
1105 struct pipe_inode_info;
1106 struct uts_namespace;
1107 
1108 struct load_weight {
1109         unsigned long weight;
1110         u32 inv_weight;
1111 };
1112 
1113 struct sched_avg {
1114         /*
1115          * These sums represent an infinite geometric series and so are bound
1116          * above by 1024/(1-y).  Thus we only need a u32 to store them for all
1117          * choices of y < 1-2^(-32)*1024.
1118          */
1119         u32 runnable_avg_sum, runnable_avg_period;
1120         u64 last_runnable_update;
1121         s64 decay_count;
1122         unsigned long load_avg_contrib;
1123 };
1124 
1125 #ifdef CONFIG_SCHEDSTATS
1126 struct sched_statistics {
1127         u64                     wait_start;
1128         u64                     wait_max;
1129         u64                     wait_count;
1130         u64                     wait_sum;
1131         u64                     iowait_count;
1132         u64                     iowait_sum;
1133 
1134         u64                     sleep_start;
1135         u64                     sleep_max;
1136         s64                     sum_sleep_runtime;
1137 
1138         u64                     block_start;
1139         u64                     block_max;
1140         u64                     exec_max;
1141         u64                     slice_max;
1142 
1143         u64                     nr_migrations_cold;
1144         u64                     nr_failed_migrations_affine;
1145         u64                     nr_failed_migrations_running;
1146         u64                     nr_failed_migrations_hot;
1147         u64                     nr_forced_migrations;
1148 
1149         u64                     nr_wakeups;
1150         u64                     nr_wakeups_sync;
1151         u64                     nr_wakeups_migrate;
1152         u64                     nr_wakeups_local;
1153         u64                     nr_wakeups_remote;
1154         u64                     nr_wakeups_affine;
1155         u64                     nr_wakeups_affine_attempts;
1156         u64                     nr_wakeups_passive;
1157         u64                     nr_wakeups_idle;
1158 };
1159 #endif
1160 
1161 struct sched_entity {
1162         struct load_weight      load;           /* for load-balancing */
1163         struct rb_node          run_node;
1164         struct list_head        group_node;
1165         unsigned int            on_rq;
1166 
1167         u64                     exec_start;
1168         u64                     sum_exec_runtime;
1169         u64                     vruntime;
1170         u64                     prev_sum_exec_runtime;
1171 
1172         u64                     nr_migrations;
1173 
1174 #ifdef CONFIG_SCHEDSTATS
1175         struct sched_statistics statistics;
1176 #endif
1177 
1178 #ifdef CONFIG_FAIR_GROUP_SCHED
1179         int                     depth;
1180         struct sched_entity     *parent;
1181         /* rq on which this entity is (to be) queued: */
1182         struct cfs_rq           *cfs_rq;
1183         /* rq "owned" by this entity/group: */
1184         struct cfs_rq           *my_q;
1185 #endif
1186 
1187 #ifdef CONFIG_SMP
1188         /* Per-entity load-tracking */
1189         struct sched_avg        avg;
1190 #endif
1191 };
1192 
1193 struct sched_rt_entity {
1194         struct list_head run_list;
1195         unsigned long timeout;
1196         unsigned long watchdog_stamp;
1197         unsigned int time_slice;
1198 
1199         struct sched_rt_entity *back;
1200 #ifdef CONFIG_RT_GROUP_SCHED
1201         struct sched_rt_entity  *parent;
1202         /* rq on which this entity is (to be) queued: */
1203         struct rt_rq            *rt_rq;
1204         /* rq "owned" by this entity/group: */
1205         struct rt_rq            *my_q;
1206 #endif
1207 };
1208 
1209 struct sched_dl_entity {
1210         struct rb_node  rb_node;
1211 
1212         /*
1213          * Original scheduling parameters. Copied here from sched_attr
1214          * during sched_setattr(), they will remain the same until
1215          * the next sched_setattr().
1216          */
1217         u64 dl_runtime;         /* maximum runtime for each instance    */
1218         u64 dl_deadline;        /* relative deadline of each instance   */
1219         u64 dl_period;          /* separation of two instances (period) */
1220         u64 dl_bw;              /* dl_runtime / dl_deadline             */
1221 
1222         /*
1223          * Actual scheduling parameters. Initialized with the values above,
1224          * they are continously updated during task execution. Note that
1225          * the remaining runtime could be < 0 in case we are in overrun.
1226          */
1227         s64 runtime;            /* remaining runtime for this instance  */
1228         u64 deadline;           /* absolute deadline for this instance  */
1229         unsigned int flags;     /* specifying the scheduler behaviour   */
1230 
1231         /*
1232          * Some bool flags:
1233          *
1234          * @dl_throttled tells if we exhausted the runtime. If so, the
1235          * task has to wait for a replenishment to be performed at the
1236          * next firing of dl_timer.
1237          *
1238          * @dl_new tells if a new instance arrived. If so we must
1239          * start executing it with full runtime and reset its absolute
1240          * deadline;
1241          *
1242          * @dl_boosted tells if we are boosted due to DI. If so we are
1243          * outside bandwidth enforcement mechanism (but only until we
1244          * exit the critical section);
1245          *
1246          * @dl_yielded tells if task gave up the cpu before consuming
1247          * all its available runtime during the last job.
1248          */
1249         int dl_throttled, dl_new, dl_boosted, dl_yielded;
1250 
1251         /*
1252          * Bandwidth enforcement timer. Each -deadline task has its
1253          * own bandwidth to be enforced, thus we need one timer per task.
1254          */
1255         struct hrtimer dl_timer;
1256 };
1257 
1258 union rcu_special {
1259         struct {
1260                 bool blocked;
1261                 bool need_qs;
1262         } b;
1263         short s;
1264 };
1265 struct rcu_node;
1266 
1267 enum perf_event_task_context {
1268         perf_invalid_context = -1,
1269         perf_hw_context = 0,
1270         perf_sw_context,
1271         perf_nr_task_contexts,
1272 };
1273 
1274 struct task_struct {
1275         volatile long state;    /* -1 unrunnable, 0 runnable, >0 stopped */
1276         void *stack;
1277         atomic_t usage;
1278         unsigned int flags;     /* per process flags, defined below */
1279         unsigned int ptrace;
1280 
1281 #ifdef CONFIG_SMP
1282         struct llist_node wake_entry;
1283         int on_cpu;
1284         struct task_struct *last_wakee;
1285         unsigned long wakee_flips;
1286         unsigned long wakee_flip_decay_ts;
1287 
1288         int wake_cpu;
1289 #endif
1290         int on_rq;
1291 
1292         int prio, static_prio, normal_prio;
1293         unsigned int rt_priority;
1294         const struct sched_class *sched_class;
1295         struct sched_entity se;
1296         struct sched_rt_entity rt;
1297 #ifdef CONFIG_CGROUP_SCHED
1298         struct task_group *sched_task_group;
1299 #endif
1300         struct sched_dl_entity dl;
1301 
1302 #ifdef CONFIG_PREEMPT_NOTIFIERS
1303         /* list of struct preempt_notifier: */
1304         struct hlist_head preempt_notifiers;
1305 #endif
1306 
1307 #ifdef CONFIG_BLK_DEV_IO_TRACE
1308         unsigned int btrace_seq;
1309 #endif
1310 
1311         unsigned int policy;
1312         int nr_cpus_allowed;
1313         cpumask_t cpus_allowed;
1314 
1315 #ifdef CONFIG_PREEMPT_RCU
1316         int rcu_read_lock_nesting;
1317         union rcu_special rcu_read_unlock_special;
1318         struct list_head rcu_node_entry;
1319 #endif /* #ifdef CONFIG_PREEMPT_RCU */
1320 #ifdef CONFIG_PREEMPT_RCU
1321         struct rcu_node *rcu_blocked_node;
1322 #endif /* #ifdef CONFIG_PREEMPT_RCU */
1323 #ifdef CONFIG_TASKS_RCU
1324         unsigned long rcu_tasks_nvcsw;
1325         bool rcu_tasks_holdout;
1326         struct list_head rcu_tasks_holdout_list;
1327         int rcu_tasks_idle_cpu;
1328 #endif /* #ifdef CONFIG_TASKS_RCU */
1329 
1330 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
1331         struct sched_info sched_info;
1332 #endif
1333 
1334         struct list_head tasks;
1335 #ifdef CONFIG_SMP
1336         struct plist_node pushable_tasks;
1337         struct rb_node pushable_dl_tasks;
1338 #endif
1339 
1340         struct mm_struct *mm, *active_mm;
1341 #ifdef CONFIG_COMPAT_BRK
1342         unsigned brk_randomized:1;
1343 #endif
1344         /* per-thread vma caching */
1345         u32 vmacache_seqnum;
1346         struct vm_area_struct *vmacache[VMACACHE_SIZE];
1347 #if defined(SPLIT_RSS_COUNTING)
1348         struct task_rss_stat    rss_stat;
1349 #endif
1350 /* task state */
1351         int exit_state;
1352         int exit_code, exit_signal;
1353         int pdeath_signal;  /*  The signal sent when the parent dies  */
1354         unsigned int jobctl;    /* JOBCTL_*, siglock protected */
1355 
1356         /* Used for emulating ABI behavior of previous Linux versions */
1357         unsigned int personality;
1358 
1359         unsigned in_execve:1;   /* Tell the LSMs that the process is doing an
1360                                  * execve */
1361         unsigned in_iowait:1;
1362 
1363         /* Revert to default priority/policy when forking */
1364         unsigned sched_reset_on_fork:1;
1365         unsigned sched_contributes_to_load:1;
1366 
1367 #ifdef CONFIG_MEMCG_KMEM
1368         unsigned memcg_kmem_skip_account:1;
1369 #endif
1370 
1371         unsigned long atomic_flags; /* Flags needing atomic access. */
1372 
1373         pid_t pid;
1374         pid_t tgid;
1375 
1376 #ifdef CONFIG_CC_STACKPROTECTOR
1377         /* Canary value for the -fstack-protector gcc feature */
1378         unsigned long stack_canary;
1379 #endif
1380         /*
1381          * pointers to (original) parent process, youngest child, younger sibling,
1382          * older sibling, respectively.  (p->father can be replaced with
1383          * p->real_parent->pid)
1384          */
1385         struct task_struct __rcu *real_parent; /* real parent process */
1386         struct task_struct __rcu *parent; /* recipient of SIGCHLD, wait4() reports */
1387         /*
1388          * children/sibling forms the list of my natural children
1389          */
1390         struct list_head children;      /* list of my children */
1391         struct list_head sibling;       /* linkage in my parent's children list */
1392         struct task_struct *group_leader;       /* threadgroup leader */
1393 
1394         /*
1395          * ptraced is the list of tasks this task is using ptrace on.
1396          * This includes both natural children and PTRACE_ATTACH targets.
1397          * p->ptrace_entry is p's link on the p->parent->ptraced list.
1398          */
1399         struct list_head ptraced;
1400         struct list_head ptrace_entry;
1401 
1402         /* PID/PID hash table linkage. */
1403         struct pid_link pids[PIDTYPE_MAX];
1404         struct list_head thread_group;
1405         struct list_head thread_node;
1406 
1407         struct completion *vfork_done;          /* for vfork() */
1408         int __user *set_child_tid;              /* CLONE_CHILD_SETTID */
1409         int __user *clear_child_tid;            /* CLONE_CHILD_CLEARTID */
1410 
1411         cputime_t utime, stime, utimescaled, stimescaled;
1412         cputime_t gtime;
1413 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
1414         struct cputime prev_cputime;
1415 #endif
1416 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1417         seqlock_t vtime_seqlock;
1418         unsigned long long vtime_snap;
1419         enum {
1420                 VTIME_SLEEPING = 0,
1421                 VTIME_USER,
1422                 VTIME_SYS,
1423         } vtime_snap_whence;
1424 #endif
1425         unsigned long nvcsw, nivcsw; /* context switch counts */
1426         u64 start_time;         /* monotonic time in nsec */
1427         u64 real_start_time;    /* boot based time in nsec */
1428 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1429         unsigned long min_flt, maj_flt;
1430 
1431         struct task_cputime cputime_expires;
1432         struct list_head cpu_timers[3];
1433 
1434 /* process credentials */
1435         const struct cred __rcu *real_cred; /* objective and real subjective task
1436                                          * credentials (COW) */
1437         const struct cred __rcu *cred;  /* effective (overridable) subjective task
1438                                          * credentials (COW) */
1439         char comm[TASK_COMM_LEN]; /* executable name excluding path
1440                                      - access with [gs]et_task_comm (which lock
1441                                        it with task_lock())
1442                                      - initialized normally by setup_new_exec */
1443 /* file system info */
1444         int link_count, total_link_count;
1445 #ifdef CONFIG_SYSVIPC
1446 /* ipc stuff */
1447         struct sysv_sem sysvsem;
1448         struct sysv_shm sysvshm;
1449 #endif
1450 #ifdef CONFIG_DETECT_HUNG_TASK
1451 /* hung task detection */
1452         unsigned long last_switch_count;
1453 #endif
1454 /* CPU-specific state of this task */
1455         struct thread_struct thread;
1456 /* filesystem information */
1457         struct fs_struct *fs;
1458 /* open file information */
1459         struct files_struct *files;
1460 /* namespaces */
1461         struct nsproxy *nsproxy;
1462 /* signal handlers */
1463         struct signal_struct *signal;
1464         struct sighand_struct *sighand;
1465 
1466         sigset_t blocked, real_blocked;
1467         sigset_t saved_sigmask; /* restored if set_restore_sigmask() was used */
1468         struct sigpending pending;
1469 
1470         unsigned long sas_ss_sp;
1471         size_t sas_ss_size;
1472         int (*notifier)(void *priv);
1473         void *notifier_data;
1474         sigset_t *notifier_mask;
1475         struct callback_head *task_works;
1476 
1477         struct audit_context *audit_context;
1478 #ifdef CONFIG_AUDITSYSCALL
1479         kuid_t loginuid;
1480         unsigned int sessionid;
1481 #endif
1482         struct seccomp seccomp;
1483 
1484 /* Thread group tracking */
1485         u32 parent_exec_id;
1486         u32 self_exec_id;
1487 /* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1488  * mempolicy */
1489         spinlock_t alloc_lock;
1490 
1491         /* Protection of the PI data structures: */
1492         raw_spinlock_t pi_lock;
1493 
1494 #ifdef CONFIG_RT_MUTEXES
1495         /* PI waiters blocked on a rt_mutex held by this task */
1496         struct rb_root pi_waiters;
1497         struct rb_node *pi_waiters_leftmost;
1498         /* Deadlock detection and priority inheritance handling */
1499         struct rt_mutex_waiter *pi_blocked_on;
1500 #endif
1501 
1502 #ifdef CONFIG_DEBUG_MUTEXES
1503         /* mutex deadlock detection */
1504         struct mutex_waiter *blocked_on;
1505 #endif
1506 #ifdef CONFIG_TRACE_IRQFLAGS
1507         unsigned int irq_events;
1508         unsigned long hardirq_enable_ip;
1509         unsigned long hardirq_disable_ip;
1510         unsigned int hardirq_enable_event;
1511         unsigned int hardirq_disable_event;
1512         int hardirqs_enabled;
1513         int hardirq_context;
1514         unsigned long softirq_disable_ip;
1515         unsigned long softirq_enable_ip;
1516         unsigned int softirq_disable_event;
1517         unsigned int softirq_enable_event;
1518         int softirqs_enabled;
1519         int softirq_context;
1520 #endif
1521 #ifdef CONFIG_LOCKDEP
1522 # define MAX_LOCK_DEPTH 48UL
1523         u64 curr_chain_key;
1524         int lockdep_depth;
1525         unsigned int lockdep_recursion;
1526         struct held_lock held_locks[MAX_LOCK_DEPTH];
1527         gfp_t lockdep_reclaim_gfp;
1528 #endif
1529 
1530 /* journalling filesystem info */
1531         void *journal_info;
1532 
1533 /* stacked block device info */
1534         struct bio_list *bio_list;
1535 
1536 #ifdef CONFIG_BLOCK
1537 /* stack plugging */
1538         struct blk_plug *plug;
1539 #endif
1540 
1541 /* VM state */
1542         struct reclaim_state *reclaim_state;
1543 
1544         struct backing_dev_info *backing_dev_info;
1545 
1546         struct io_context *io_context;
1547 
1548         unsigned long ptrace_message;
1549         siginfo_t *last_siginfo; /* For ptrace use.  */
1550         struct task_io_accounting ioac;
1551 #if defined(CONFIG_TASK_XACCT)
1552         u64 acct_rss_mem1;      /* accumulated rss usage */
1553         u64 acct_vm_mem1;       /* accumulated virtual memory usage */
1554         cputime_t acct_timexpd; /* stime + utime since last update */
1555 #endif
1556 #ifdef CONFIG_CPUSETS
1557         nodemask_t mems_allowed;        /* Protected by alloc_lock */
1558         seqcount_t mems_allowed_seq;    /* Seqence no to catch updates */
1559         int cpuset_mem_spread_rotor;
1560         int cpuset_slab_spread_rotor;
1561 #endif
1562 #ifdef CONFIG_CGROUPS
1563         /* Control Group info protected by css_set_lock */
1564         struct css_set __rcu *cgroups;
1565         /* cg_list protected by css_set_lock and tsk->alloc_lock */
1566         struct list_head cg_list;
1567 #endif
1568 #ifdef CONFIG_FUTEX
1569         struct robust_list_head __user *robust_list;
1570 #ifdef CONFIG_COMPAT
1571         struct compat_robust_list_head __user *compat_robust_list;
1572 #endif
1573         struct list_head pi_state_list;
1574         struct futex_pi_state *pi_state_cache;
1575 #endif
1576 #ifdef CONFIG_PERF_EVENTS
1577         struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1578         struct mutex perf_event_mutex;
1579         struct list_head perf_event_list;
1580 #endif
1581 #ifdef CONFIG_DEBUG_PREEMPT
1582         unsigned long preempt_disable_ip;
1583 #endif
1584 #ifdef CONFIG_NUMA
1585         struct mempolicy *mempolicy;    /* Protected by alloc_lock */
1586         short il_next;
1587         short pref_node_fork;
1588 #endif
1589 #ifdef CONFIG_NUMA_BALANCING
1590         int numa_scan_seq;
1591         unsigned int numa_scan_period;
1592         unsigned int numa_scan_period_max;
1593         int numa_preferred_nid;
1594         unsigned long numa_migrate_retry;
1595         u64 node_stamp;                 /* migration stamp  */
1596         u64 last_task_numa_placement;
1597         u64 last_sum_exec_runtime;
1598         struct callback_head numa_work;
1599 
1600         struct list_head numa_entry;
1601         struct numa_group *numa_group;
1602 
1603         /*
1604          * numa_faults is an array split into four regions:
1605          * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1606          * in this precise order.
1607          *
1608          * faults_memory: Exponential decaying average of faults on a per-node
1609          * basis. Scheduling placement decisions are made based on these
1610          * counts. The values remain static for the duration of a PTE scan.
1611          * faults_cpu: Track the nodes the process was running on when a NUMA
1612          * hinting fault was incurred.
1613          * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1614          * during the current scan window. When the scan completes, the counts
1615          * in faults_memory and faults_cpu decay and these values are copied.
1616          */
1617         unsigned long *numa_faults;
1618         unsigned long total_numa_faults;
1619 
1620         /*
1621          * numa_faults_locality tracks if faults recorded during the last
1622          * scan window were remote/local. The task scan period is adapted
1623          * based on the locality of the faults with different weights
1624          * depending on whether they were shared or private faults
1625          */
1626         unsigned long numa_faults_locality[2];
1627 
1628         unsigned long numa_pages_migrated;
1629 #endif /* CONFIG_NUMA_BALANCING */
1630 
1631         struct rcu_head rcu;
1632 
1633         /*
1634          * cache last used pipe for splice
1635          */
1636         struct pipe_inode_info *splice_pipe;
1637 
1638         struct page_frag task_frag;
1639 
1640 #ifdef  CONFIG_TASK_DELAY_ACCT
1641         struct task_delay_info *delays;
1642 #endif
1643 #ifdef CONFIG_FAULT_INJECTION
1644         int make_it_fail;
1645 #endif
1646         /*
1647          * when (nr_dirtied >= nr_dirtied_pause), it's time to call
1648          * balance_dirty_pages() for some dirty throttling pause
1649          */
1650         int nr_dirtied;
1651         int nr_dirtied_pause;
1652         unsigned long dirty_paused_when; /* start of a write-and-pause period */
1653 
1654 #ifdef CONFIG_LATENCYTOP
1655         int latency_record_count;
1656         struct latency_record latency_record[LT_SAVECOUNT];
1657 #endif
1658         /*
1659          * time slack values; these are used to round up poll() and
1660          * select() etc timeout values. These are in nanoseconds.
1661          */
1662         unsigned long timer_slack_ns;
1663         unsigned long default_timer_slack_ns;
1664 
1665 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1666         /* Index of current stored address in ret_stack */
1667         int curr_ret_stack;
1668         /* Stack of return addresses for return function tracing */
1669         struct ftrace_ret_stack *ret_stack;
1670         /* time stamp for last schedule */
1671         unsigned long long ftrace_timestamp;
1672         /*
1673          * Number of functions that haven't been traced
1674          * because of depth overrun.
1675          */
1676         atomic_t trace_overrun;
1677         /* Pause for the tracing */
1678         atomic_t tracing_graph_pause;
1679 #endif
1680 #ifdef CONFIG_TRACING
1681         /* state flags for use by tracers */
1682         unsigned long trace;
1683         /* bitmask and counter of trace recursion */
1684         unsigned long trace_recursion;
1685 #endif /* CONFIG_TRACING */
1686 #ifdef CONFIG_MEMCG
1687         struct memcg_oom_info {
1688                 struct mem_cgroup *memcg;
1689                 gfp_t gfp_mask;
1690                 int order;
1691                 unsigned int may_oom:1;
1692         } memcg_oom;
1693 #endif
1694 #ifdef CONFIG_UPROBES
1695         struct uprobe_task *utask;
1696 #endif
1697 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1698         unsigned int    sequential_io;
1699         unsigned int    sequential_io_avg;
1700 #endif
1701 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1702         unsigned long   task_state_change;
1703 #endif
1704 };
1705 
1706 /* Future-safe accessor for struct task_struct's cpus_allowed. */
1707 #define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
1708 
1709 #define TNF_MIGRATED    0x01
1710 #define TNF_NO_GROUP    0x02
1711 #define TNF_SHARED      0x04
1712 #define TNF_FAULT_LOCAL 0x08
1713 
1714 #ifdef CONFIG_NUMA_BALANCING
1715 extern void task_numa_fault(int last_node, int node, int pages, int flags);
1716 extern pid_t task_numa_group_id(struct task_struct *p);
1717 extern void set_numabalancing_state(bool enabled);
1718 extern void task_numa_free(struct task_struct *p);
1719 extern bool should_numa_migrate_memory(struct task_struct *p, struct page *page,
1720                                         int src_nid, int dst_cpu);
1721 #else
1722 static inline void task_numa_fault(int last_node, int node, int pages,
1723                                    int flags)
1724 {
1725 }
1726 static inline pid_t task_numa_group_id(struct task_struct *p)
1727 {
1728         return 0;
1729 }
1730 static inline void set_numabalancing_state(bool enabled)
1731 {
1732 }
1733 static inline void task_numa_free(struct task_struct *p)
1734 {
1735 }
1736 static inline bool should_numa_migrate_memory(struct task_struct *p,
1737                                 struct page *page, int src_nid, int dst_cpu)
1738 {
1739         return true;
1740 }
1741 #endif
1742 
1743 static inline struct pid *task_pid(struct task_struct *task)
1744 {
1745         return task->pids[PIDTYPE_PID].pid;
1746 }
1747 
1748 static inline struct pid *task_tgid(struct task_struct *task)
1749 {
1750         return task->group_leader->pids[PIDTYPE_PID].pid;
1751 }
1752 
1753 /*
1754  * Without tasklist or rcu lock it is not safe to dereference
1755  * the result of task_pgrp/task_session even if task == current,
1756  * we can race with another thread doing sys_setsid/sys_setpgid.
1757  */
1758 static inline struct pid *task_pgrp(struct task_struct *task)
1759 {
1760         return task->group_leader->pids[PIDTYPE_PGID].pid;
1761 }
1762 
1763 static inline struct pid *task_session(struct task_struct *task)
1764 {
1765         return task->group_leader->pids[PIDTYPE_SID].pid;
1766 }
1767 
1768 struct pid_namespace;
1769 
1770 /*
1771  * the helpers to get the task's different pids as they are seen
1772  * from various namespaces
1773  *
1774  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1775  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1776  *                     current.
1777  * task_xid_nr_ns()  : id seen from the ns specified;
1778  *
1779  * set_task_vxid()   : assigns a virtual id to a task;
1780  *
1781  * see also pid_nr() etc in include/linux/pid.h
1782  */
1783 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
1784                         struct pid_namespace *ns);
1785 
1786 static inline pid_t task_pid_nr(struct task_struct *tsk)
1787 {
1788         return tsk->pid;
1789 }
1790 
1791 static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
1792                                         struct pid_namespace *ns)
1793 {
1794         return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1795 }
1796 
1797 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1798 {
1799         return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1800 }
1801 
1802 
1803 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1804 {
1805         return tsk->tgid;
1806 }
1807 
1808 pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1809 
1810 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1811 {
1812         return pid_vnr(task_tgid(tsk));
1813 }
1814 
1815 
1816 static inline int pid_alive(const struct task_struct *p);
1817 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1818 {
1819         pid_t pid = 0;
1820 
1821         rcu_read_lock();
1822         if (pid_alive(tsk))
1823                 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1824         rcu_read_unlock();
1825 
1826         return pid;
1827 }
1828 
1829 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1830 {
1831         return task_ppid_nr_ns(tsk, &init_pid_ns);
1832 }
1833 
1834 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
1835                                         struct pid_namespace *ns)
1836 {
1837         return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1838 }
1839 
1840 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1841 {
1842         return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1843 }
1844 
1845 
1846 static inline pid_t task_session_nr_ns(struct task_struct *tsk,
1847                                         struct pid_namespace *ns)
1848 {
1849         return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1850 }
1851 
1852 static inline pid_t task_session_vnr(struct task_struct *tsk)
1853 {
1854         return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1855 }
1856 
1857 /* obsolete, do not use */
1858 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1859 {
1860         return task_pgrp_nr_ns(tsk, &init_pid_ns);
1861 }
1862 
1863 /**
1864  * pid_alive - check that a task structure is not stale
1865  * @p: Task structure to be checked.
1866  *
1867  * Test if a process is not yet dead (at most zombie state)
1868  * If pid_alive fails, then pointers within the task structure
1869  * can be stale and must not be dereferenced.
1870  *
1871  * Return: 1 if the process is alive. 0 otherwise.
1872  */
1873 static inline int pid_alive(const struct task_struct *p)
1874 {
1875         return p->pids[PIDTYPE_PID].pid != NULL;
1876 }
1877 
1878 /**
1879  * is_global_init - check if a task structure is init
1880  * @tsk: Task structure to be checked.
1881  *
1882  * Check if a task structure is the first user space task the kernel created.
1883  *
1884  * Return: 1 if the task structure is init. 0 otherwise.
1885  */
1886 static inline int is_global_init(struct task_struct *tsk)
1887 {
1888         return tsk->pid == 1;
1889 }
1890 
1891 extern struct pid *cad_pid;
1892 
1893 extern void free_task(struct task_struct *tsk);
1894 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
1895 
1896 extern void __put_task_struct(struct task_struct *t);
1897 
1898 static inline void put_task_struct(struct task_struct *t)
1899 {
1900         if (atomic_dec_and_test(&t->usage))
1901                 __put_task_struct(t);
1902 }
1903 
1904 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1905 extern void task_cputime(struct task_struct *t,
1906                          cputime_t *utime, cputime_t *stime);
1907 extern void task_cputime_scaled(struct task_struct *t,
1908                                 cputime_t *utimescaled, cputime_t *stimescaled);
1909 extern cputime_t task_gtime(struct task_struct *t);
1910 #else
1911 static inline void task_cputime(struct task_struct *t,
1912                                 cputime_t *utime, cputime_t *stime)
1913 {
1914         if (utime)
1915                 *utime = t->utime;
1916         if (stime)
1917                 *stime = t->stime;
1918 }
1919 
1920 static inline void task_cputime_scaled(struct task_struct *t,
1921                                        cputime_t *utimescaled,
1922                                        cputime_t *stimescaled)
1923 {
1924         if (utimescaled)
1925                 *utimescaled = t->utimescaled;
1926         if (stimescaled)
1927                 *stimescaled = t->stimescaled;
1928 }
1929 
1930 static inline cputime_t task_gtime(struct task_struct *t)
1931 {
1932         return t->gtime;
1933 }
1934 #endif
1935 extern void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
1936 extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
1937 
1938 /*
1939  * Per process flags
1940  */
1941 #define PF_EXITING      0x00000004      /* getting shut down */
1942 #define PF_EXITPIDONE   0x00000008      /* pi exit done on shut down */
1943 #define PF_VCPU         0x00000010      /* I'm a virtual CPU */
1944 #define PF_WQ_WORKER    0x00000020      /* I'm a workqueue worker */
1945 #define PF_FORKNOEXEC   0x00000040      /* forked but didn't exec */
1946 #define PF_MCE_PROCESS  0x00000080      /* process policy on mce errors */
1947 #define PF_SUPERPRIV    0x00000100      /* used super-user privileges */
1948 #define PF_DUMPCORE     0x00000200      /* dumped core */
1949 #define PF_SIGNALED     0x00000400      /* killed by a signal */
1950 #define PF_MEMALLOC     0x00000800      /* Allocating memory */
1951 #define PF_NPROC_EXCEEDED 0x00001000    /* set_user noticed that RLIMIT_NPROC was exceeded */
1952 #define PF_USED_MATH    0x00002000      /* if unset the fpu must be initialized before use */
1953 #define PF_USED_ASYNC   0x00004000      /* used async_schedule*(), used by module init */
1954 #define PF_NOFREEZE     0x00008000      /* this thread should not be frozen */
1955 #define PF_FROZEN       0x00010000      /* frozen for system suspend */
1956 #define PF_FSTRANS      0x00020000      /* inside a filesystem transaction */
1957 #define PF_KSWAPD       0x00040000      /* I am kswapd */
1958 #define PF_MEMALLOC_NOIO 0x00080000     /* Allocating memory without IO involved */
1959 #define PF_LESS_THROTTLE 0x00100000     /* Throttle me less: I clean memory */
1960 #define PF_KTHREAD      0x00200000      /* I am a kernel thread */
1961 #define PF_RANDOMIZE    0x00400000      /* randomize virtual address space */
1962 #define PF_SWAPWRITE    0x00800000      /* Allowed to write to swap */
1963 #define PF_NO_SETAFFINITY 0x04000000    /* Userland is not allowed to meddle with cpus_allowed */
1964 #define PF_MCE_EARLY    0x08000000      /* Early kill for mce process policy */
1965 #define PF_MUTEX_TESTER 0x20000000      /* Thread belongs to the rt mutex tester */
1966 #define PF_FREEZER_SKIP 0x40000000      /* Freezer should not count it as freezable */
1967 #define PF_SUSPEND_TASK 0x80000000      /* this thread called freeze_processes and should not be frozen */
1968 
1969 /*
1970  * Only the _current_ task can read/write to tsk->flags, but other
1971  * tasks can access tsk->flags in readonly mode for example
1972  * with tsk_used_math (like during threaded core dumping).
1973  * There is however an exception to this rule during ptrace
1974  * or during fork: the ptracer task is allowed to write to the
1975  * child->flags of its traced child (same goes for fork, the parent
1976  * can write to the child->flags), because we're guaranteed the
1977  * child is not running and in turn not changing child->flags
1978  * at the same time the parent does it.
1979  */
1980 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1981 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1982 #define clear_used_math() clear_stopped_child_used_math(current)
1983 #define set_used_math() set_stopped_child_used_math(current)
1984 #define conditional_stopped_child_used_math(condition, child) \
1985         do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1986 #define conditional_used_math(condition) \
1987         conditional_stopped_child_used_math(condition, current)
1988 #define copy_to_stopped_child_used_math(child) \
1989         do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1990 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1991 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1992 #define used_math() tsk_used_math(current)
1993 
1994 /* __GFP_IO isn't allowed if PF_MEMALLOC_NOIO is set in current->flags
1995  * __GFP_FS is also cleared as it implies __GFP_IO.
1996  */
1997 static inline gfp_t memalloc_noio_flags(gfp_t flags)
1998 {
1999         if (unlikely(current->flags & PF_MEMALLOC_NOIO))
2000                 flags &= ~(__GFP_IO | __GFP_FS);
2001         return flags;
2002 }
2003 
2004 static inline unsigned int memalloc_noio_save(void)
2005 {
2006         unsigned int flags = current->flags & PF_MEMALLOC_NOIO;
2007         current->flags |= PF_MEMALLOC_NOIO;
2008         return flags;
2009 }
2010 
2011 static inline void memalloc_noio_restore(unsigned int flags)
2012 {
2013         current->flags = (current->flags & ~PF_MEMALLOC_NOIO) | flags;
2014 }
2015 
2016 /* Per-process atomic flags. */
2017 #define PFA_NO_NEW_PRIVS 0      /* May not gain new privileges. */
2018 #define PFA_SPREAD_PAGE  1      /* Spread page cache over cpuset */
2019 #define PFA_SPREAD_SLAB  2      /* Spread some slab caches over cpuset */
2020 
2021 
2022 #define TASK_PFA_TEST(name, func)                                       \
2023         static inline bool task_##func(struct task_struct *p)           \
2024         { return test_bit(PFA_##name, &p->atomic_flags); }
2025 #define TASK_PFA_SET(name, func)                                        \
2026         static inline void task_set_##func(struct task_struct *p)       \
2027         { set_bit(PFA_##name, &p->atomic_flags); }
2028 #define TASK_PFA_CLEAR(name, func)                                      \
2029         static inline void task_clear_##func(struct task_struct *p)     \
2030         { clear_bit(PFA_##name, &p->atomic_flags); }
2031 
2032 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
2033 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
2034 
2035 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
2036 TASK_PFA_SET(SPREAD_PAGE, spread_page)
2037 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
2038 
2039 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
2040 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
2041 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
2042 
2043 /*
2044  * task->jobctl flags
2045  */
2046 #define JOBCTL_STOP_SIGMASK     0xffff  /* signr of the last group stop */
2047 
2048 #define JOBCTL_STOP_DEQUEUED_BIT 16     /* stop signal dequeued */
2049 #define JOBCTL_STOP_PENDING_BIT 17      /* task should stop for group stop */
2050 #define JOBCTL_STOP_CONSUME_BIT 18      /* consume group stop count */
2051 #define JOBCTL_TRAP_STOP_BIT    19      /* trap for STOP */
2052 #define JOBCTL_TRAP_NOTIFY_BIT  20      /* trap for NOTIFY */
2053 #define JOBCTL_TRAPPING_BIT     21      /* switching to TRACED */
2054 #define JOBCTL_LISTENING_BIT    22      /* ptracer is listening for events */
2055 
2056 #define JOBCTL_STOP_DEQUEUED    (1 << JOBCTL_STOP_DEQUEUED_BIT)
2057 #define JOBCTL_STOP_PENDING     (1 << JOBCTL_STOP_PENDING_BIT)
2058 #define JOBCTL_STOP_CONSUME     (1 << JOBCTL_STOP_CONSUME_BIT)
2059 #define JOBCTL_TRAP_STOP        (1 << JOBCTL_TRAP_STOP_BIT)
2060 #define JOBCTL_TRAP_NOTIFY      (1 << JOBCTL_TRAP_NOTIFY_BIT)
2061 #define JOBCTL_TRAPPING         (1 << JOBCTL_TRAPPING_BIT)
2062 #define JOBCTL_LISTENING        (1 << JOBCTL_LISTENING_BIT)
2063 
2064 #define JOBCTL_TRAP_MASK        (JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
2065 #define JOBCTL_PENDING_MASK     (JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)
2066 
2067 extern bool task_set_jobctl_pending(struct task_struct *task,
2068                                     unsigned int mask);
2069 extern void task_clear_jobctl_trapping(struct task_struct *task);
2070 extern void task_clear_jobctl_pending(struct task_struct *task,
2071                                       unsigned int mask);
2072 
2073 static inline void rcu_copy_process(struct task_struct *p)
2074 {
2075 #ifdef CONFIG_PREEMPT_RCU
2076         p->rcu_read_lock_nesting = 0;
2077         p->rcu_read_unlock_special.s = 0;
2078         p->rcu_blocked_node = NULL;
2079         INIT_LIST_HEAD(&p->rcu_node_entry);
2080 #endif /* #ifdef CONFIG_PREEMPT_RCU */
2081 #ifdef CONFIG_TASKS_RCU
2082         p->rcu_tasks_holdout = false;
2083         INIT_LIST_HEAD(&p->rcu_tasks_holdout_list);
2084         p->rcu_tasks_idle_cpu = -1;
2085 #endif /* #ifdef CONFIG_TASKS_RCU */
2086 }
2087 
2088 static inline void tsk_restore_flags(struct task_struct *task,
2089                                 unsigned long orig_flags, unsigned long flags)
2090 {
2091         task->flags &= ~flags;
2092         task->flags |= orig_flags & flags;
2093 }
2094 
2095 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur,
2096                                      const struct cpumask *trial);
2097 extern int task_can_attach(struct task_struct *p,
2098                            const struct cpumask *cs_cpus_allowed);
2099 #ifdef CONFIG_SMP
2100 extern void do_set_cpus_allowed(struct task_struct *p,
2101                                const struct cpumask *new_mask);
2102 
2103 extern int set_cpus_allowed_ptr(struct task_struct *p,
2104                                 const struct cpumask *new_mask);
2105 #else
2106 static inline void do_set_cpus_allowed(struct task_struct *p,
2107                                       const struct cpumask *new_mask)
2108 {
2109 }
2110 static inline int set_cpus_allowed_ptr(struct task_struct *p,
2111                                        const struct cpumask *new_mask)
2112 {
2113         if (!cpumask_test_cpu(0, new_mask))
2114                 return -EINVAL;
2115         return 0;
2116 }
2117 #endif
2118 
2119 #ifdef CONFIG_NO_HZ_COMMON
2120 void calc_load_enter_idle(void);
2121 void calc_load_exit_idle(void);
2122 #else
2123 static inline void calc_load_enter_idle(void) { }
2124 static inline void calc_load_exit_idle(void) { }
2125 #endif /* CONFIG_NO_HZ_COMMON */
2126 
2127 #ifndef CONFIG_CPUMASK_OFFSTACK
2128 static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
2129 {
2130         return set_cpus_allowed_ptr(p, &new_mask);
2131 }
2132 #endif
2133 
2134 /*
2135  * Do not use outside of architecture code which knows its limitations.
2136  *
2137  * sched_clock() has no promise of monotonicity or bounded drift between
2138  * CPUs, use (which you should not) requires disabling IRQs.
2139  *
2140  * Please use one of the three interfaces below.
2141  */
2142 extern unsigned long long notrace sched_clock(void);
2143 /*
2144  * See the comment in kernel/sched/clock.c
2145  */
2146 extern u64 cpu_clock(int cpu);
2147 extern u64 local_clock(void);
2148 extern u64 sched_clock_cpu(int cpu);
2149 
2150 
2151 extern void sched_clock_init(void);
2152 
2153 #ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
2154 static inline void sched_clock_tick(void)
2155 {
2156 }
2157 
2158 static inline void sched_clock_idle_sleep_event(void)
2159 {
2160 }
2161 
2162 static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
2163 {
2164 }
2165 #else
2166 /*
2167  * Architectures can set this to 1 if they have specified
2168  * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
2169  * but then during bootup it turns out that sched_clock()
2170  * is reliable after all:
2171  */
2172 extern int sched_clock_stable(void);
2173 extern void set_sched_clock_stable(void);
2174 extern void clear_sched_clock_stable(void);
2175 
2176 extern void sched_clock_tick(void);
2177 extern void sched_clock_idle_sleep_event(void);
2178 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2179 #endif
2180 
2181 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
2182 /*
2183  * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
2184  * The reason for this explicit opt-in is not to have perf penalty with
2185  * slow sched_clocks.
2186  */
2187 extern void enable_sched_clock_irqtime(void);
2188 extern void disable_sched_clock_irqtime(void);
2189 #else
2190 static inline void enable_sched_clock_irqtime(void) {}
2191 static inline void disable_sched_clock_irqtime(void) {}
2192 #endif
2193 
2194 extern unsigned long long
2195 task_sched_runtime(struct task_struct *task);
2196 
2197 /* sched_exec is called by processes performing an exec */
2198 #ifdef CONFIG_SMP
2199 extern void sched_exec(void);
2200 #else
2201 #define sched_exec()   {}
2202 #endif
2203 
2204 extern void sched_clock_idle_sleep_event(void);
2205 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2206 
2207 #ifdef CONFIG_HOTPLUG_CPU
2208 extern void idle_task_exit(void);
2209 #else
2210 static inline void idle_task_exit(void) {}
2211 #endif
2212 
2213 #if defined(CONFIG_NO_HZ_COMMON) && defined(CONFIG_SMP)
2214 extern void wake_up_nohz_cpu(int cpu);
2215 #else
2216 static inline void wake_up_nohz_cpu(int cpu) { }
2217 #endif
2218 
2219 #ifdef CONFIG_NO_HZ_FULL
2220 extern bool sched_can_stop_tick(void);
2221 extern u64 scheduler_tick_max_deferment(void);
2222 #else
2223 static inline bool sched_can_stop_tick(void) { return false; }
2224 #endif
2225 
2226 #ifdef CONFIG_SCHED_AUTOGROUP
2227 extern void sched_autogroup_create_attach(struct task_struct *p);
2228 extern void sched_autogroup_detach(struct task_struct *p);
2229 extern void sched_autogroup_fork(struct signal_struct *sig);
2230 extern void sched_autogroup_exit(struct signal_struct *sig);
2231 #ifdef CONFIG_PROC_FS
2232 extern void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m);
2233 extern int proc_sched_autogroup_set_nice(struct task_struct *p, int nice);
2234 #endif
2235 #else
2236 static inline void sched_autogroup_create_attach(struct task_struct *p) { }
2237 static inline void sched_autogroup_detach(struct task_struct *p) { }
2238 static inline void sched_autogroup_fork(struct signal_struct *sig) { }
2239 static inline void sched_autogroup_exit(struct signal_struct *sig) { }
2240 #endif
2241 
2242 extern int yield_to(struct task_struct *p, bool preempt);
2243 extern void set_user_nice(struct task_struct *p, long nice);
2244 extern int task_prio(const struct task_struct *p);
2245 /**
2246  * task_nice - return the nice value of a given task.
2247  * @p: the task in question.
2248  *
2249  * Return: The nice value [ -20 ... 0 ... 19 ].
2250  */
2251 static inline int task_nice(const struct task_struct *p)
2252 {
2253         return PRIO_TO_NICE((p)->static_prio);
2254 }
2255 extern int can_nice(const struct task_struct *p, const int nice);
2256 extern int task_curr(const struct task_struct *p);
2257 extern int idle_cpu(int cpu);
2258 extern int sched_setscheduler(struct task_struct *, int,
2259                               const struct sched_param *);
2260 extern int sched_setscheduler_nocheck(struct task_struct *, int,
2261                                       const struct sched_param *);
2262 extern int sched_setattr(struct task_struct *,
2263                          const struct sched_attr *);
2264 extern struct task_struct *idle_task(int cpu);
2265 /**
2266  * is_idle_task - is the specified task an idle task?
2267  * @p: the task in question.
2268  *
2269  * Return: 1 if @p is an idle task. 0 otherwise.
2270  */
2271 static inline bool is_idle_task(const struct task_struct *p)
2272 {
2273         return p->pid == 0;
2274 }
2275 extern struct task_struct *curr_task(int cpu);
2276 extern void set_curr_task(int cpu, struct task_struct *p);
2277 
2278 void yield(void);
2279 
2280 /*
2281  * The default (Linux) execution domain.
2282  */
2283 extern struct exec_domain       default_exec_domain;
2284 
2285 union thread_union {
2286         struct thread_info thread_info;
2287         unsigned long stack[THREAD_SIZE/sizeof(long)];
2288 };
2289 
2290 #ifndef __HAVE_ARCH_KSTACK_END
2291 static inline int kstack_end(void *addr)
2292 {
2293         /* Reliable end of stack detection:
2294          * Some APM bios versions misalign the stack
2295          */
2296         return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
2297 }
2298 #endif
2299 
2300 extern union thread_union init_thread_union;
2301 extern struct task_struct init_task;
2302 
2303 extern struct   mm_struct init_mm;
2304 
2305 extern struct pid_namespace init_pid_ns;
2306 
2307 /*
2308  * find a task by one of its numerical ids
2309  *
2310  * find_task_by_pid_ns():
2311  *      finds a task by its pid in the specified namespace
2312  * find_task_by_vpid():
2313  *      finds a task by its virtual pid
2314  *
2315  * see also find_vpid() etc in include/linux/pid.h
2316  */
2317 
2318 extern struct task_struct *find_task_by_vpid(pid_t nr);
2319 extern struct task_struct *find_task_by_pid_ns(pid_t nr,
2320                 struct pid_namespace *ns);
2321 
2322 /* per-UID process charging. */
2323 extern struct user_struct * alloc_uid(kuid_t);
2324 static inline struct user_struct *get_uid(struct user_struct *u)
2325 {
2326         atomic_inc(&u->__count);
2327         return u;
2328 }
2329 extern void free_uid(struct user_struct *);
2330 
2331 #include <asm/current.h>
2332 
2333 extern void xtime_update(unsigned long ticks);
2334 
2335 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2336 extern int wake_up_process(struct task_struct *tsk);
2337 extern void wake_up_new_task(struct task_struct *tsk);
2338 #ifdef CONFIG_SMP
2339  extern void kick_process(struct task_struct *tsk);
2340 #else
2341  static inline void kick_process(struct task_struct *tsk) { }
2342 #endif
2343 extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
2344 extern void sched_dead(struct task_struct *p);
2345 
2346 extern void proc_caches_init(void);
2347 extern void flush_signals(struct task_struct *);
2348 extern void __flush_signals(struct task_struct *);
2349 extern void ignore_signals(struct task_struct *);
2350 extern void flush_signal_handlers(struct task_struct *, int force_default);
2351 extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
2352 
2353 static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
2354 {
2355         unsigned long flags;
2356         int ret;
2357 
2358         spin_lock_irqsave(&tsk->sighand->siglock, flags);
2359         ret = dequeue_signal(tsk, mask, info);
2360         spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
2361 
2362         return ret;
2363 }
2364 
2365 extern void block_all_signals(int (*notifier)(void *priv), void *priv,
2366                               sigset_t *mask);
2367 extern void unblock_all_signals(void);
2368 extern void release_task(struct task_struct * p);
2369 extern int send_sig_info(int, struct siginfo *, struct task_struct *);
2370 extern int force_sigsegv(int, struct task_struct *);
2371 extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2372 extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
2373 extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2374 extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *,
2375                                 const struct cred *, u32);
2376 extern int kill_pgrp(struct pid *pid, int sig, int priv);
2377 extern int kill_pid(struct pid *pid, int sig, int priv);
2378 extern int kill_proc_info(int, struct siginfo *, pid_t);
2379 extern __must_check bool do_notify_parent(struct task_struct *, int);
2380 extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
2381 extern void force_sig(int, struct task_struct *);
2382 extern int send_sig(int, struct task_struct *, int);
2383 extern int zap_other_threads(struct task_struct *p);
2384 extern struct sigqueue *sigqueue_alloc(void);
2385 extern void sigqueue_free(struct sigqueue *);
2386 extern int send_sigqueue(struct sigqueue *,  struct task_struct *, int group);
2387 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
2388 
2389 static inline void restore_saved_sigmask(void)
2390 {
2391         if (test_and_clear_restore_sigmask())
2392                 __set_current_blocked(&current->saved_sigmask);
2393 }
2394 
2395 static inline sigset_t *sigmask_to_save(void)
2396 {
2397         sigset_t *res = &current->blocked;
2398         if (unlikely(test_restore_sigmask()))
2399                 res = &current->saved_sigmask;
2400         return res;
2401 }
2402 
2403 static inline int kill_cad_pid(int sig, int priv)
2404 {
2405         return kill_pid(cad_pid, sig, priv);
2406 }
2407 
2408 /* These can be the second arg to send_sig_info/send_group_sig_info.  */
2409 #define SEND_SIG_NOINFO ((struct siginfo *) 0)
2410 #define SEND_SIG_PRIV   ((struct siginfo *) 1)
2411 #define SEND_SIG_FORCED ((struct siginfo *) 2)
2412 
2413 /*
2414  * True if we are on the alternate signal stack.
2415  */
2416 static inline int on_sig_stack(unsigned long sp)
2417 {
2418 #ifdef CONFIG_STACK_GROWSUP
2419         return sp >= current->sas_ss_sp &&
2420                 sp - current->sas_ss_sp < current->sas_ss_size;
2421 #else
2422         return sp > current->sas_ss_sp &&
2423                 sp - current->sas_ss_sp <= current->sas_ss_size;
2424 #endif
2425 }
2426 
2427 static inline int sas_ss_flags(unsigned long sp)
2428 {
2429         if (!current->sas_ss_size)
2430                 return SS_DISABLE;
2431 
2432         return on_sig_stack(sp) ? SS_ONSTACK : 0;
2433 }
2434 
2435 static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig)
2436 {
2437         if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))
2438 #ifdef CONFIG_STACK_GROWSUP
2439                 return current->sas_ss_sp;
2440 #else
2441                 return current->sas_ss_sp + current->sas_ss_size;
2442 #endif
2443         return sp;
2444 }
2445 
2446 /*
2447  * Routines for handling mm_structs
2448  */
2449 extern struct mm_struct * mm_alloc(void);
2450 
2451 /* mmdrop drops the mm and the page tables */
2452 extern void __mmdrop(struct mm_struct *);
2453 static inline void mmdrop(struct mm_struct * mm)
2454 {
2455         if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2456                 __mmdrop(mm);
2457 }
2458 
2459 /* mmput gets rid of the mappings and all user-space */
2460 extern void mmput(struct mm_struct *);
2461 /* Grab a reference to a task's mm, if it is not already going away */
2462 extern struct mm_struct *get_task_mm(struct task_struct *task);
2463 /*
2464  * Grab a reference to a task's mm, if it is not already going away
2465  * and ptrace_may_access with the mode parameter passed to it
2466  * succeeds.
2467  */
2468 extern struct mm_struct *mm_access(struct task_struct *task, unsigned int mode);
2469 /* Remove the current tasks stale references to the old mm_struct */
2470 extern void mm_release(struct task_struct *, struct mm_struct *);
2471 
2472 extern int copy_thread(unsigned long, unsigned long, unsigned long,
2473                         struct task_struct *);
2474 extern void flush_thread(void);
2475 extern void exit_thread(void);
2476 
2477 extern void exit_files(struct task_struct *);
2478 extern void __cleanup_sighand(struct sighand_struct *);
2479 
2480 extern void exit_itimers(struct signal_struct *);
2481 extern void flush_itimer_signals(void);
2482 
2483 extern void do_group_exit(int);
2484 
2485 extern int do_execve(struct filename *,
2486                      const char __user * const __user *,
2487                      const char __user * const __user *);
2488 extern int do_execveat(int, struct filename *,
2489                        const char __user * const __user *,
2490                        const char __user * const __user *,
2491                        int);
2492 extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
2493 struct task_struct *fork_idle(int);
2494 extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
2495 
2496 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
2497 static inline void set_task_comm(struct task_struct *tsk, const char *from)
2498 {
2499         __set_task_comm(tsk, from, false);
2500 }
2501 extern char *get_task_comm(char *to, struct task_struct *tsk);
2502 
2503 #ifdef CONFIG_SMP
2504 void scheduler_ipi(void);
2505 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
2506 #else
2507 static inline void scheduler_ipi(void) { }
2508 static inline unsigned long wait_task_inactive(struct task_struct *p,
2509                                                long match_state)
2510 {
2511         return 1;
2512 }
2513 #endif
2514 
2515 #define next_task(p) \
2516         list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
2517 
2518 #define for_each_process(p) \
2519         for (p = &init_task ; (p = next_task(p)) != &init_task ; )
2520 
2521 extern bool current_is_single_threaded(void);
2522 
2523 /*
2524  * Careful: do_each_thread/while_each_thread is a double loop so
2525  *          'break' will not work as expected - use goto instead.
2526  */
2527 #define do_each_thread(g, t) \
2528         for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
2529 
2530 #define while_each_thread(g, t) \
2531         while ((t = next_thread(t)) != g)
2532 
2533 #define __for_each_thread(signal, t)    \
2534         list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node)
2535 
2536 #define for_each_thread(p, t)           \
2537         __for_each_thread((p)->signal, t)
2538 
2539 /* Careful: this is a double loop, 'break' won't work as expected. */
2540 #define for_each_process_thread(p, t)   \
2541         for_each_process(p) for_each_thread(p, t)
2542 
2543 static inline int get_nr_threads(struct task_struct *tsk)
2544 {
2545         return tsk->signal->nr_threads;
2546 }
2547 
2548 static inline bool thread_group_leader(struct task_struct *p)
2549 {
2550         return p->exit_signal >= 0;
2551 }
2552 
2553 /* Do to the insanities of de_thread it is possible for a process
2554  * to have the pid of the thread group leader without actually being
2555  * the thread group leader.  For iteration through the pids in proc
2556  * all we care about is that we have a task with the appropriate
2557  * pid, we don't actually care if we have the right task.
2558  */
2559 static inline bool has_group_leader_pid(struct task_struct *p)
2560 {
2561         return task_pid(p) == p->signal->leader_pid;
2562 }
2563 
2564 static inline
2565 bool same_thread_group(struct task_struct *p1, struct task_struct *p2)
2566 {
2567         return p1->signal == p2->signal;
2568 }
2569 
2570 static inline struct task_struct *next_thread(const struct task_struct *p)
2571 {
2572         return list_entry_rcu(p->thread_group.next,
2573                               struct task_struct, thread_group);
2574 }
2575 
2576 static inline int thread_group_empty(struct task_struct *p)
2577 {
2578         return list_empty(&p->thread_group);
2579 }
2580 
2581 #define delay_group_leader(p) \
2582                 (thread_group_leader(p) && !thread_group_empty(p))
2583 
2584 /*
2585  * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
2586  * subscriptions and synchronises with wait4().  Also used in procfs.  Also
2587  * pins the final release of task.io_context.  Also protects ->cpuset and
2588  * ->cgroup.subsys[]. And ->vfork_done.
2589  *
2590  * Nests both inside and outside of read_lock(&tasklist_lock).
2591  * It must not be nested with write_lock_irq(&tasklist_lock),
2592  * neither inside nor outside.
2593  */
2594 static inline void task_lock(struct task_struct *p)
2595 {
2596         spin_lock(&p->alloc_lock);
2597 }
2598 
2599 static inline void task_unlock(struct task_struct *p)
2600 {
2601         spin_unlock(&p->alloc_lock);
2602 }
2603 
2604 extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
2605                                                         unsigned long *flags);
2606 
2607 static inline struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
2608                                                        unsigned long *flags)
2609 {
2610         struct sighand_struct *ret;
2611 
2612         ret = __lock_task_sighand(tsk, flags);
2613         (void)__cond_lock(&tsk->sighand->siglock, ret);
2614         return ret;
2615 }
2616 
2617 static inline void unlock_task_sighand(struct task_struct *tsk,
2618                                                 unsigned long *flags)
2619 {
2620         spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
2621 }
2622 
2623 #ifdef CONFIG_CGROUPS
2624 static inline void threadgroup_change_begin(struct task_struct *tsk)
2625 {
2626         down_read(&tsk->signal->group_rwsem);
2627 }
2628 static inline void threadgroup_change_end(struct task_struct *tsk)
2629 {
2630         up_read(&tsk->signal->group_rwsem);
2631 }
2632 
2633 /**
2634  * threadgroup_lock - lock threadgroup
2635  * @tsk: member task of the threadgroup to lock
2636  *
2637  * Lock the threadgroup @tsk belongs to.  No new task is allowed to enter
2638  * and member tasks aren't allowed to exit (as indicated by PF_EXITING) or
2639  * change ->group_leader/pid.  This is useful for cases where the threadgroup
2640  * needs to stay stable across blockable operations.
2641  *
2642  * fork and exit paths explicitly call threadgroup_change_{begin|end}() for
2643  * synchronization.  While held, no new task will be added to threadgroup
2644  * and no existing live task will have its PF_EXITING set.
2645  *
2646  * de_thread() does threadgroup_change_{begin|end}() when a non-leader
2647  * sub-thread becomes a new leader.
2648  */
2649 static inline void threadgroup_lock(struct task_struct *tsk)
2650 {
2651         down_write(&tsk->signal->group_rwsem);
2652 }
2653 
2654 /**
2655  * threadgroup_unlock - unlock threadgroup
2656  * @tsk: member task of the threadgroup to unlock
2657  *
2658  * Reverse threadgroup_lock().
2659  */
2660 static inline void threadgroup_unlock(struct task_struct *tsk)
2661 {
2662         up_write(&tsk->signal->group_rwsem);
2663 }
2664 #else
2665 static inline void threadgroup_change_begin(struct task_struct *tsk) {}
2666 static inline void threadgroup_change_end(struct task_struct *tsk) {}
2667 static inline void threadgroup_lock(struct task_struct *tsk) {}
2668 static inline void threadgroup_unlock(struct task_struct *tsk) {}
2669 #endif
2670 
2671 #ifndef __HAVE_THREAD_FUNCTIONS
2672 
2673 #define task_thread_info(task)  ((struct thread_info *)(task)->stack)
2674 #define task_stack_page(task)   ((task)->stack)
2675 
2676 static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
2677 {
2678         *task_thread_info(p) = *task_thread_info(org);
2679         task_thread_info(p)->task = p;
2680 }
2681 
2682 /*
2683  * Return the address of the last usable long on the stack.
2684  *
2685  * When the stack grows down, this is just above the thread
2686  * info struct. Going any lower will corrupt the threadinfo.
2687  *
2688  * When the stack grows up, this is the highest address.
2689  * Beyond that position, we corrupt data on the next page.
2690  */
2691 static inline unsigned long *end_of_stack(struct task_struct *p)
2692 {
2693 #ifdef CONFIG_STACK_GROWSUP
2694         return (unsigned long *)((unsigned long)task_thread_info(p) + THREAD_SIZE) - 1;
2695 #else
2696         return (unsigned long *)(task_thread_info(p) + 1);
2697 #endif
2698 }
2699 
2700 #endif
2701 #define task_stack_end_corrupted(task) \
2702                 (*(end_of_stack(task)) != STACK_END_MAGIC)
2703 
2704 static inline int object_is_on_stack(void *obj)
2705 {
2706         void *stack = task_stack_page(current);
2707 
2708         return (obj >= stack) && (obj < (stack + THREAD_SIZE));
2709 }
2710 
2711 extern void thread_info_cache_init(void);
2712 
2713 #ifdef CONFIG_DEBUG_STACK_USAGE
2714 static inline unsigned long stack_not_used(struct task_struct *p)
2715 {
2716         unsigned long *n = end_of_stack(p);
2717 
2718         do {    /* Skip over canary */
2719                 n++;
2720         } while (!*n);
2721 
2722         return (unsigned long)n - (unsigned long)end_of_stack(p);
2723 }
2724 #endif
2725 extern void set_task_stack_end_magic(struct task_struct *tsk);
2726 
2727 /* set thread flags in other task's structures
2728  * - see asm/thread_info.h for TIF_xxxx flags available
2729  */
2730 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2731 {
2732         set_ti_thread_flag(task_thread_info(tsk), flag);
2733 }
2734 
2735 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2736 {
2737         clear_ti_thread_flag(task_thread_info(tsk), flag);
2738 }
2739 
2740 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2741 {
2742         return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2743 }
2744 
2745 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2746 {
2747         return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2748 }
2749 
2750 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2751 {
2752         return test_ti_thread_flag(task_thread_info(tsk), flag);
2753 }
2754 
2755 static inline void set_tsk_need_resched(struct task_struct *tsk)
2756 {
2757         set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2758 }
2759 
2760 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2761 {
2762         clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2763 }
2764 
2765 static inline int test_tsk_need_resched(struct task_struct *tsk)
2766 {
2767         return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2768 }
2769 
2770 static inline int restart_syscall(void)
2771 {
2772         set_tsk_thread_flag(current, TIF_SIGPENDING);
2773         return -ERESTARTNOINTR;
2774 }
2775 
2776 static inline int signal_pending(struct task_struct *p)
2777 {
2778         return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
2779 }
2780 
2781 static inline int __fatal_signal_pending(struct task_struct *p)
2782 {
2783         return unlikely(sigismember(&p->pending.signal, SIGKILL));
2784 }
2785 
2786 static inline int fatal_signal_pending(struct task_struct *p)
2787 {
2788         return signal_pending(p) && __fatal_signal_pending(p);
2789 }
2790 
2791 static inline int signal_pending_state(long state, struct task_struct *p)
2792 {
2793         if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
2794                 return 0;
2795         if (!signal_pending(p))
2796                 return 0;
2797 
2798         return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
2799 }
2800 
2801 /*
2802  * cond_resched() and cond_resched_lock(): latency reduction via
2803  * explicit rescheduling in places that are safe. The return
2804  * value indicates whether a reschedule was done in fact.
2805  * cond_resched_lock() will drop the spinlock before scheduling,
2806  * cond_resched_softirq() will enable bhs before scheduling.
2807  */
2808 extern int _cond_resched(void);
2809 
2810 #define cond_resched() ({                       \
2811         ___might_sleep(__FILE__, __LINE__, 0);  \
2812         _cond_resched();                        \
2813 })
2814 
2815 extern int __cond_resched_lock(spinlock_t *lock);
2816 
2817 #ifdef CONFIG_PREEMPT_COUNT
2818 #define PREEMPT_LOCK_OFFSET     PREEMPT_OFFSET
2819 #else
2820 #define PREEMPT_LOCK_OFFSET     0
2821 #endif
2822 
2823 #define cond_resched_lock(lock) ({                              \
2824         ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
2825         __cond_resched_lock(lock);                              \
2826 })
2827 
2828 extern int __cond_resched_softirq(void);
2829 
2830 #define cond_resched_softirq() ({                                       \
2831         ___might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET);     \
2832         __cond_resched_softirq();                                       \
2833 })
2834 
2835 static inline void cond_resched_rcu(void)
2836 {
2837 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
2838         rcu_read_unlock();
2839         cond_resched();
2840         rcu_read_lock();
2841 #endif
2842 }
2843 
2844 /*
2845  * Does a critical section need to be broken due to another
2846  * task waiting?: (technically does not depend on CONFIG_PREEMPT,
2847  * but a general need for low latency)
2848  */
2849 static inline int spin_needbreak(spinlock_t *lock)
2850 {
2851 #ifdef CONFIG_PREEMPT
2852         return spin_is_contended(lock);
2853 #else
2854         return 0;
2855 #endif
2856 }
2857 
2858 /*
2859  * Idle thread specific functions to determine the need_resched
2860  * polling state.
2861  */
2862 #ifdef TIF_POLLING_NRFLAG
2863 static inline int tsk_is_polling(struct task_struct *p)
2864 {
2865         return test_tsk_thread_flag(p, TIF_POLLING_NRFLAG);
2866 }
2867 
2868 static inline void __current_set_polling(void)
2869 {
2870         set_thread_flag(TIF_POLLING_NRFLAG);
2871 }
2872 
2873 static inline bool __must_check current_set_polling_and_test(void)
2874 {
2875         __current_set_polling();
2876 
2877         /*
2878          * Polling state must be visible before we test NEED_RESCHED,
2879          * paired by resched_curr()
2880          */
2881         smp_mb__after_atomic();
2882 
2883         return unlikely(tif_need_resched());
2884 }
2885 
2886 static inline void __current_clr_polling(void)
2887 {
2888         clear_thread_flag(TIF_POLLING_NRFLAG);
2889 }
2890 
2891 static inline bool __must_check current_clr_polling_and_test(void)
2892 {
2893         __current_clr_polling();
2894 
2895         /*
2896          * Polling state must be visible before we test NEED_RESCHED,
2897          * paired by resched_curr()
2898          */
2899         smp_mb__after_atomic();
2900 
2901         return unlikely(tif_need_resched());
2902 }
2903 
2904 #else
2905 static inline int tsk_is_polling(struct task_struct *p) { return 0; }
2906 static inline void __current_set_polling(void) { }
2907 static inline void __current_clr_polling(void) { }
2908 
2909 static inline bool __must_check current_set_polling_and_test(void)
2910 {
2911         return unlikely(tif_need_resched());
2912 }
2913 static inline bool __must_check current_clr_polling_and_test(void)
2914 {
2915         return unlikely(tif_need_resched());
2916 }
2917 #endif
2918 
2919 static inline void current_clr_polling(void)
2920 {
2921         __current_clr_polling();
2922 
2923         /*
2924          * Ensure we check TIF_NEED_RESCHED after we clear the polling bit.
2925          * Once the bit is cleared, we'll get IPIs with every new
2926          * TIF_NEED_RESCHED and the IPI handler, scheduler_ipi(), will also
2927          * fold.
2928          */
2929         smp_mb(); /* paired with resched_curr() */
2930 
2931         preempt_fold_need_resched();
2932 }
2933 
2934 static __always_inline bool need_resched(void)
2935 {
2936         return unlikely(tif_need_resched());
2937 }
2938 
2939 /*
2940  * Thread group CPU time accounting.
2941  */
2942 void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
2943 void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
2944 
2945 static inline void thread_group_cputime_init(struct signal_struct *sig)
2946 {
2947         raw_spin_lock_init(&sig->cputimer.lock);
2948 }
2949 
2950 /*
2951  * Reevaluate whether the task has signals pending delivery.
2952  * Wake the task if so.
2953  * This is required every time the blocked sigset_t changes.
2954  * callers must hold sighand->siglock.
2955  */
2956 extern void recalc_sigpending_and_wake(struct task_struct *t);
2957 extern void recalc_sigpending(void);
2958 
2959 extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
2960 
2961 static inline void signal_wake_up(struct task_struct *t, bool resume)
2962 {
2963         signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0);
2964 }
2965 static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
2966 {
2967         signal_wake_up_state(t, resume ? __TASK_TRACED : 0);
2968 }
2969 
2970 /*
2971  * Wrappers for p->thread_info->cpu access. No-op on UP.
2972  */
2973 #ifdef CONFIG_SMP
2974 
2975 static inline unsigned int task_cpu(const struct task_struct *p)
2976 {
2977         return task_thread_info(p)->cpu;
2978 }
2979 
2980 static inline int task_node(const struct task_struct *p)
2981 {
2982         return cpu_to_node(task_cpu(p));
2983 }
2984 
2985 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2986 
2987 #else
2988 
2989 static inline unsigned int task_cpu(const struct task_struct *p)
2990 {
2991         return 0;
2992 }
2993 
2994 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2995 {
2996 }
2997 
2998 #endif /* CONFIG_SMP */
2999 
3000 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
3001 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
3002 
3003 #ifdef CONFIG_CGROUP_SCHED
3004 extern struct task_group root_task_group;
3005 #endif /* CONFIG_CGROUP_SCHED */
3006 
3007 extern int task_can_switch_user(struct user_struct *up,
3008                                         struct task_struct *tsk);
3009 
3010 #ifdef CONFIG_TASK_XACCT
3011 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
3012 {
3013         tsk->ioac.rchar += amt;
3014 }
3015 
3016 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
3017 {
3018         tsk->ioac.wchar += amt;
3019 }
3020 
3021 static inline void inc_syscr(struct task_struct *tsk)
3022 {
3023         tsk->ioac.syscr++;
3024 }
3025 
3026 static inline void inc_syscw(struct task_struct *tsk)
3027 {
3028         tsk->ioac.syscw++;
3029 }
3030 #else
3031 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
3032 {
3033 }
3034 
3035 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
3036 {
3037 }
3038 
3039 static inline void inc_syscr(struct task_struct *tsk)
3040 {
3041 }
3042 
3043 static inline void inc_syscw(struct task_struct *tsk)
3044 {
3045 }
3046 #endif
3047 
3048 #ifndef TASK_SIZE_OF
3049 #define TASK_SIZE_OF(tsk)       TASK_SIZE
3050 #endif
3051 
3052 #ifdef CONFIG_MEMCG
3053 extern void mm_update_next_owner(struct mm_struct *mm);
3054 #else
3055 static inline void mm_update_next_owner(struct mm_struct *mm)
3056 {
3057 }
3058 #endif /* CONFIG_MEMCG */
3059 
3060 static inline unsigned long task_rlimit(const struct task_struct *tsk,
3061                 unsigned int limit)
3062 {
3063         return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_cur);
3064 }
3065 
3066 static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
3067                 unsigned int limit)
3068 {
3069         return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_max);
3070 }
3071 
3072 static inline unsigned long rlimit(unsigned int limit)
3073 {
3074         return task_rlimit(current, limit);
3075 }
3076 
3077 static inline unsigned long rlimit_max(unsigned int limit)
3078 {
3079         return task_rlimit_max(current, limit);
3080 }
3081 
3082 #endif
3083 

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