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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.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/seccomp.h>
 44 #include <linux/rcupdate.h>
 45 #include <linux/rculist.h>
 46 #include <linux/rtmutex.h>
 47 
 48 #include <linux/time.h>
 49 #include <linux/param.h>
 50 #include <linux/resource.h>
 51 #include <linux/timer.h>
 52 #include <linux/hrtimer.h>
 53 #include <linux/kcov.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 #include <linux/cgroup-defs.h>
 62 
 63 #include <asm/processor.h>
 64 
 65 #define SCHED_ATTR_SIZE_VER0    48      /* sizeof first published struct */
 66 
 67 /*
 68  * Extended scheduling parameters data structure.
 69  *
 70  * This is needed because the original struct sched_param can not be
 71  * altered without introducing ABI issues with legacy applications
 72  * (e.g., in sched_getparam()).
 73  *
 74  * However, the possibility of specifying more than just a priority for
 75  * the tasks may be useful for a wide variety of application fields, e.g.,
 76  * multimedia, streaming, automation and control, and many others.
 77  *
 78  * This variant (sched_attr) is meant at describing a so-called
 79  * sporadic time-constrained task. In such model a task is specified by:
 80  *  - the activation period or minimum instance inter-arrival time;
 81  *  - the maximum (or average, depending on the actual scheduling
 82  *    discipline) computation time of all instances, a.k.a. runtime;
 83  *  - the deadline (relative to the actual activation time) of each
 84  *    instance.
 85  * Very briefly, a periodic (sporadic) task asks for the execution of
 86  * some specific computation --which is typically called an instance--
 87  * (at most) every period. Moreover, each instance typically lasts no more
 88  * than the runtime and must be completed by time instant t equal to
 89  * the instance activation time + the deadline.
 90  *
 91  * This is reflected by the actual fields of the sched_attr structure:
 92  *
 93  *  @size               size of the structure, for fwd/bwd compat.
 94  *
 95  *  @sched_policy       task's scheduling policy
 96  *  @sched_flags        for customizing the scheduler behaviour
 97  *  @sched_nice         task's nice value      (SCHED_NORMAL/BATCH)
 98  *  @sched_priority     task's static priority (SCHED_FIFO/RR)
 99  *  @sched_deadline     representative of the task's deadline
100  *  @sched_runtime      representative of the task's runtime
101  *  @sched_period       representative of the task's period
102  *
103  * Given this task model, there are a multiplicity of scheduling algorithms
104  * and policies, that can be used to ensure all the tasks will make their
105  * timing constraints.
106  *
107  * As of now, the SCHED_DEADLINE policy (sched_dl scheduling class) is the
108  * only user of this new interface. More information about the algorithm
109  * available in the scheduling class file or in Documentation/.
110  */
111 struct sched_attr {
112         u32 size;
113 
114         u32 sched_policy;
115         u64 sched_flags;
116 
117         /* SCHED_NORMAL, SCHED_BATCH */
118         s32 sched_nice;
119 
120         /* SCHED_FIFO, SCHED_RR */
121         u32 sched_priority;
122 
123         /* SCHED_DEADLINE */
124         u64 sched_runtime;
125         u64 sched_deadline;
126         u64 sched_period;
127 };
128 
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 struct nameidata;
137 
138 #define VMACACHE_BITS 2
139 #define VMACACHE_SIZE (1U << VMACACHE_BITS)
140 #define VMACACHE_MASK (VMACACHE_SIZE - 1)
141 
142 /*
143  * These are the constant used to fake the fixed-point load-average
144  * counting. Some notes:
145  *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
146  *    a load-average precision of 10 bits integer + 11 bits fractional
147  *  - if you want to count load-averages more often, you need more
148  *    precision, or rounding will get you. With 2-second counting freq,
149  *    the EXP_n values would be 1981, 2034 and 2043 if still using only
150  *    11 bit fractions.
151  */
152 extern unsigned long avenrun[];         /* Load averages */
153 extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
154 
155 #define FSHIFT          11              /* nr of bits of precision */
156 #define FIXED_1         (1<<FSHIFT)     /* 1.0 as fixed-point */
157 #define LOAD_FREQ       (5*HZ+1)        /* 5 sec intervals */
158 #define EXP_1           1884            /* 1/exp(5sec/1min) as fixed-point */
159 #define EXP_5           2014            /* 1/exp(5sec/5min) */
160 #define EXP_15          2037            /* 1/exp(5sec/15min) */
161 
162 #define CALC_LOAD(load,exp,n) \
163         load *= exp; \
164         load += n*(FIXED_1-exp); \
165         load >>= FSHIFT;
166 
167 extern unsigned long total_forks;
168 extern int nr_threads;
169 DECLARE_PER_CPU(unsigned long, process_counts);
170 extern int nr_processes(void);
171 extern unsigned long nr_running(void);
172 extern bool single_task_running(void);
173 extern unsigned long nr_iowait(void);
174 extern unsigned long nr_iowait_cpu(int cpu);
175 extern void get_iowait_load(unsigned long *nr_waiters, unsigned long *load);
176 
177 extern void calc_global_load(unsigned long ticks);
178 
179 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
180 extern void cpu_load_update_nohz_start(void);
181 extern void cpu_load_update_nohz_stop(void);
182 #else
183 static inline void cpu_load_update_nohz_start(void) { }
184 static inline void cpu_load_update_nohz_stop(void) { }
185 #endif
186 
187 extern void dump_cpu_task(int cpu);
188 
189 struct seq_file;
190 struct cfs_rq;
191 struct task_group;
192 #ifdef CONFIG_SCHED_DEBUG
193 extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
194 extern void proc_sched_set_task(struct task_struct *p);
195 #endif
196 
197 /*
198  * Task state bitmask. NOTE! These bits are also
199  * encoded in fs/proc/array.c: get_task_state().
200  *
201  * We have two separate sets of flags: task->state
202  * is about runnability, while task->exit_state are
203  * about the task exiting. Confusing, but this way
204  * modifying one set can't modify the other one by
205  * mistake.
206  */
207 #define TASK_RUNNING            0
208 #define TASK_INTERRUPTIBLE      1
209 #define TASK_UNINTERRUPTIBLE    2
210 #define __TASK_STOPPED          4
211 #define __TASK_TRACED           8
212 /* in tsk->exit_state */
213 #define EXIT_DEAD               16
214 #define EXIT_ZOMBIE             32
215 #define EXIT_TRACE              (EXIT_ZOMBIE | EXIT_DEAD)
216 /* in tsk->state again */
217 #define TASK_DEAD               64
218 #define TASK_WAKEKILL           128
219 #define TASK_WAKING             256
220 #define TASK_PARKED             512
221 #define TASK_NOLOAD             1024
222 #define TASK_NEW                2048
223 #define TASK_STATE_MAX          4096
224 
225 #define TASK_STATE_TO_CHAR_STR "RSDTtXZxKWPNn"
226 
227 extern char ___assert_task_state[1 - 2*!!(
228                 sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
229 
230 /* Convenience macros for the sake of set_task_state */
231 #define TASK_KILLABLE           (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
232 #define TASK_STOPPED            (TASK_WAKEKILL | __TASK_STOPPED)
233 #define TASK_TRACED             (TASK_WAKEKILL | __TASK_TRACED)
234 
235 #define TASK_IDLE               (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
236 
237 /* Convenience macros for the sake of wake_up */
238 #define TASK_NORMAL             (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
239 #define TASK_ALL                (TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
240 
241 /* get_task_state() */
242 #define TASK_REPORT             (TASK_RUNNING | TASK_INTERRUPTIBLE | \
243                                  TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
244                                  __TASK_TRACED | EXIT_ZOMBIE | EXIT_DEAD)
245 
246 #define task_is_traced(task)    ((task->state & __TASK_TRACED) != 0)
247 #define task_is_stopped(task)   ((task->state & __TASK_STOPPED) != 0)
248 #define task_is_stopped_or_traced(task) \
249                         ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
250 #define task_contributes_to_load(task)  \
251                                 ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
252                                  (task->flags & PF_FROZEN) == 0 && \
253                                  (task->state & TASK_NOLOAD) == 0)
254 
255 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
256 
257 #define __set_task_state(tsk, state_value)                      \
258         do {                                                    \
259                 (tsk)->task_state_change = _THIS_IP_;           \
260                 (tsk)->state = (state_value);                   \
261         } while (0)
262 #define set_task_state(tsk, state_value)                        \
263         do {                                                    \
264                 (tsk)->task_state_change = _THIS_IP_;           \
265                 smp_store_mb((tsk)->state, (state_value));              \
266         } while (0)
267 
268 /*
269  * set_current_state() includes a barrier so that the write of current->state
270  * is correctly serialised wrt the caller's subsequent test of whether to
271  * actually sleep:
272  *
273  *      set_current_state(TASK_UNINTERRUPTIBLE);
274  *      if (do_i_need_to_sleep())
275  *              schedule();
276  *
277  * If the caller does not need such serialisation then use __set_current_state()
278  */
279 #define __set_current_state(state_value)                        \
280         do {                                                    \
281                 current->task_state_change = _THIS_IP_;         \
282                 current->state = (state_value);                 \
283         } while (0)
284 #define set_current_state(state_value)                          \
285         do {                                                    \
286                 current->task_state_change = _THIS_IP_;         \
287                 smp_store_mb(current->state, (state_value));            \
288         } while (0)
289 
290 #else
291 
292 #define __set_task_state(tsk, state_value)              \
293         do { (tsk)->state = (state_value); } while (0)
294 #define set_task_state(tsk, state_value)                \
295         smp_store_mb((tsk)->state, (state_value))
296 
297 /*
298  * set_current_state() includes a barrier so that the write of current->state
299  * is correctly serialised wrt the caller's subsequent test of whether to
300  * actually sleep:
301  *
302  *      set_current_state(TASK_UNINTERRUPTIBLE);
303  *      if (do_i_need_to_sleep())
304  *              schedule();
305  *
306  * If the caller does not need such serialisation then use __set_current_state()
307  */
308 #define __set_current_state(state_value)                \
309         do { current->state = (state_value); } while (0)
310 #define set_current_state(state_value)                  \
311         smp_store_mb(current->state, (state_value))
312 
313 #endif
314 
315 /* Task command name length */
316 #define TASK_COMM_LEN 16
317 
318 #include <linux/spinlock.h>
319 
320 /*
321  * This serializes "schedule()" and also protects
322  * the run-queue from deletions/modifications (but
323  * _adding_ to the beginning of the run-queue has
324  * a separate lock).
325  */
326 extern rwlock_t tasklist_lock;
327 extern spinlock_t mmlist_lock;
328 
329 struct task_struct;
330 
331 #ifdef CONFIG_PROVE_RCU
332 extern int lockdep_tasklist_lock_is_held(void);
333 #endif /* #ifdef CONFIG_PROVE_RCU */
334 
335 extern void sched_init(void);
336 extern void sched_init_smp(void);
337 extern asmlinkage void schedule_tail(struct task_struct *prev);
338 extern void init_idle(struct task_struct *idle, int cpu);
339 extern void init_idle_bootup_task(struct task_struct *idle);
340 
341 extern cpumask_var_t cpu_isolated_map;
342 
343 extern int runqueue_is_locked(int cpu);
344 
345 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
346 extern void nohz_balance_enter_idle(int cpu);
347 extern void set_cpu_sd_state_idle(void);
348 extern int get_nohz_timer_target(void);
349 #else
350 static inline void nohz_balance_enter_idle(int cpu) { }
351 static inline void set_cpu_sd_state_idle(void) { }
352 #endif
353 
354 /*
355  * Only dump TASK_* tasks. (0 for all tasks)
356  */
357 extern void show_state_filter(unsigned long state_filter);
358 
359 static inline void show_state(void)
360 {
361         show_state_filter(0);
362 }
363 
364 extern void show_regs(struct pt_regs *);
365 
366 /*
367  * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
368  * task), SP is the stack pointer of the first frame that should be shown in the back
369  * trace (or NULL if the entire call-chain of the task should be shown).
370  */
371 extern void show_stack(struct task_struct *task, unsigned long *sp);
372 
373 extern void cpu_init (void);
374 extern void trap_init(void);
375 extern void update_process_times(int user);
376 extern void scheduler_tick(void);
377 extern int sched_cpu_starting(unsigned int cpu);
378 extern int sched_cpu_activate(unsigned int cpu);
379 extern int sched_cpu_deactivate(unsigned int cpu);
380 
381 #ifdef CONFIG_HOTPLUG_CPU
382 extern int sched_cpu_dying(unsigned int cpu);
383 #else
384 # define sched_cpu_dying        NULL
385 #endif
386 
387 extern void sched_show_task(struct task_struct *p);
388 
389 #ifdef CONFIG_LOCKUP_DETECTOR
390 extern void touch_softlockup_watchdog_sched(void);
391 extern void touch_softlockup_watchdog(void);
392 extern void touch_softlockup_watchdog_sync(void);
393 extern void touch_all_softlockup_watchdogs(void);
394 extern int proc_dowatchdog_thresh(struct ctl_table *table, int write,
395                                   void __user *buffer,
396                                   size_t *lenp, loff_t *ppos);
397 extern unsigned int  softlockup_panic;
398 extern unsigned int  hardlockup_panic;
399 void lockup_detector_init(void);
400 #else
401 static inline void touch_softlockup_watchdog_sched(void)
402 {
403 }
404 static inline void touch_softlockup_watchdog(void)
405 {
406 }
407 static inline void touch_softlockup_watchdog_sync(void)
408 {
409 }
410 static inline void touch_all_softlockup_watchdogs(void)
411 {
412 }
413 static inline void lockup_detector_init(void)
414 {
415 }
416 #endif
417 
418 #ifdef CONFIG_DETECT_HUNG_TASK
419 void reset_hung_task_detector(void);
420 #else
421 static inline void reset_hung_task_detector(void)
422 {
423 }
424 #endif
425 
426 /* Attach to any functions which should be ignored in wchan output. */
427 #define __sched         __attribute__((__section__(".sched.text")))
428 
429 /* Linker adds these: start and end of __sched functions */
430 extern char __sched_text_start[], __sched_text_end[];
431 
432 /* Is this address in the __sched functions? */
433 extern int in_sched_functions(unsigned long addr);
434 
435 #define MAX_SCHEDULE_TIMEOUT    LONG_MAX
436 extern signed long schedule_timeout(signed long timeout);
437 extern signed long schedule_timeout_interruptible(signed long timeout);
438 extern signed long schedule_timeout_killable(signed long timeout);
439 extern signed long schedule_timeout_uninterruptible(signed long timeout);
440 extern signed long schedule_timeout_idle(signed long timeout);
441 asmlinkage void schedule(void);
442 extern void schedule_preempt_disabled(void);
443 
444 extern long io_schedule_timeout(long timeout);
445 
446 static inline void io_schedule(void)
447 {
448         io_schedule_timeout(MAX_SCHEDULE_TIMEOUT);
449 }
450 
451 void __noreturn do_task_dead(void);
452 
453 struct nsproxy;
454 struct user_namespace;
455 
456 #ifdef CONFIG_MMU
457 extern void arch_pick_mmap_layout(struct mm_struct *mm);
458 extern unsigned long
459 arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
460                        unsigned long, unsigned long);
461 extern unsigned long
462 arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
463                           unsigned long len, unsigned long pgoff,
464                           unsigned long flags);
465 #else
466 static inline void arch_pick_mmap_layout(struct mm_struct *mm) {}
467 #endif
468 
469 #define SUID_DUMP_DISABLE       0       /* No setuid dumping */
470 #define SUID_DUMP_USER          1       /* Dump as user of process */
471 #define SUID_DUMP_ROOT          2       /* Dump as root */
472 
473 /* mm flags */
474 
475 /* for SUID_DUMP_* above */
476 #define MMF_DUMPABLE_BITS 2
477 #define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
478 
479 extern void set_dumpable(struct mm_struct *mm, int value);
480 /*
481  * This returns the actual value of the suid_dumpable flag. For things
482  * that are using this for checking for privilege transitions, it must
483  * test against SUID_DUMP_USER rather than treating it as a boolean
484  * value.
485  */
486 static inline int __get_dumpable(unsigned long mm_flags)
487 {
488         return mm_flags & MMF_DUMPABLE_MASK;
489 }
490 
491 static inline int get_dumpable(struct mm_struct *mm)
492 {
493         return __get_dumpable(mm->flags);
494 }
495 
496 /* coredump filter bits */
497 #define MMF_DUMP_ANON_PRIVATE   2
498 #define MMF_DUMP_ANON_SHARED    3
499 #define MMF_DUMP_MAPPED_PRIVATE 4
500 #define MMF_DUMP_MAPPED_SHARED  5
501 #define MMF_DUMP_ELF_HEADERS    6
502 #define MMF_DUMP_HUGETLB_PRIVATE 7
503 #define MMF_DUMP_HUGETLB_SHARED  8
504 #define MMF_DUMP_DAX_PRIVATE    9
505 #define MMF_DUMP_DAX_SHARED     10
506 
507 #define MMF_DUMP_FILTER_SHIFT   MMF_DUMPABLE_BITS
508 #define MMF_DUMP_FILTER_BITS    9
509 #define MMF_DUMP_FILTER_MASK \
510         (((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
511 #define MMF_DUMP_FILTER_DEFAULT \
512         ((1 << MMF_DUMP_ANON_PRIVATE) | (1 << MMF_DUMP_ANON_SHARED) |\
513          (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
514 
515 #ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
516 # define MMF_DUMP_MASK_DEFAULT_ELF      (1 << MMF_DUMP_ELF_HEADERS)
517 #else
518 # define MMF_DUMP_MASK_DEFAULT_ELF      0
519 #endif
520                                         /* leave room for more dump flags */
521 #define MMF_VM_MERGEABLE        16      /* KSM may merge identical pages */
522 #define MMF_VM_HUGEPAGE         17      /* set when VM_HUGEPAGE is set on vma */
523 #define MMF_EXE_FILE_CHANGED    18      /* see prctl_set_mm_exe_file() */
524 
525 #define MMF_HAS_UPROBES         19      /* has uprobes */
526 #define MMF_RECALC_UPROBES      20      /* MMF_HAS_UPROBES can be wrong */
527 #define MMF_OOM_SKIP            21      /* mm is of no interest for the OOM killer */
528 #define MMF_UNSTABLE            22      /* mm is unstable for copy_from_user */
529 #define MMF_HUGE_ZERO_PAGE      23      /* mm has ever used the global huge zero page */
530 
531 #define MMF_INIT_MASK           (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
532 
533 struct sighand_struct {
534         atomic_t                count;
535         struct k_sigaction      action[_NSIG];
536         spinlock_t              siglock;
537         wait_queue_head_t       signalfd_wqh;
538 };
539 
540 struct pacct_struct {
541         int                     ac_flag;
542         long                    ac_exitcode;
543         unsigned long           ac_mem;
544         cputime_t               ac_utime, ac_stime;
545         unsigned long           ac_minflt, ac_majflt;
546 };
547 
548 struct cpu_itimer {
549         cputime_t expires;
550         cputime_t incr;
551         u32 error;
552         u32 incr_error;
553 };
554 
555 /**
556  * struct prev_cputime - snaphsot of system and user cputime
557  * @utime: time spent in user mode
558  * @stime: time spent in system mode
559  * @lock: protects the above two fields
560  *
561  * Stores previous user/system time values such that we can guarantee
562  * monotonicity.
563  */
564 struct prev_cputime {
565 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
566         cputime_t utime;
567         cputime_t stime;
568         raw_spinlock_t lock;
569 #endif
570 };
571 
572 static inline void prev_cputime_init(struct prev_cputime *prev)
573 {
574 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
575         prev->utime = prev->stime = 0;
576         raw_spin_lock_init(&prev->lock);
577 #endif
578 }
579 
580 /**
581  * struct task_cputime - collected CPU time counts
582  * @utime:              time spent in user mode, in &cputime_t units
583  * @stime:              time spent in kernel mode, in &cputime_t units
584  * @sum_exec_runtime:   total time spent on the CPU, in nanoseconds
585  *
586  * This structure groups together three kinds of CPU time that are tracked for
587  * threads and thread groups.  Most things considering CPU time want to group
588  * these counts together and treat all three of them in parallel.
589  */
590 struct task_cputime {
591         cputime_t utime;
592         cputime_t stime;
593         unsigned long long sum_exec_runtime;
594 };
595 
596 /* Alternate field names when used to cache expirations. */
597 #define virt_exp        utime
598 #define prof_exp        stime
599 #define sched_exp       sum_exec_runtime
600 
601 #define INIT_CPUTIME    \
602         (struct task_cputime) {                                 \
603                 .utime = 0,                                     \
604                 .stime = 0,                                     \
605                 .sum_exec_runtime = 0,                          \
606         }
607 
608 /*
609  * This is the atomic variant of task_cputime, which can be used for
610  * storing and updating task_cputime statistics without locking.
611  */
612 struct task_cputime_atomic {
613         atomic64_t utime;
614         atomic64_t stime;
615         atomic64_t sum_exec_runtime;
616 };
617 
618 #define INIT_CPUTIME_ATOMIC \
619         (struct task_cputime_atomic) {                          \
620                 .utime = ATOMIC64_INIT(0),                      \
621                 .stime = ATOMIC64_INIT(0),                      \
622                 .sum_exec_runtime = ATOMIC64_INIT(0),           \
623         }
624 
625 #define PREEMPT_DISABLED        (PREEMPT_DISABLE_OFFSET + PREEMPT_ENABLED)
626 
627 /*
628  * Disable preemption until the scheduler is running -- use an unconditional
629  * value so that it also works on !PREEMPT_COUNT kernels.
630  *
631  * Reset by start_kernel()->sched_init()->init_idle()->init_idle_preempt_count().
632  */
633 #define INIT_PREEMPT_COUNT      PREEMPT_OFFSET
634 
635 /*
636  * Initial preempt_count value; reflects the preempt_count schedule invariant
637  * which states that during context switches:
638  *
639  *    preempt_count() == 2*PREEMPT_DISABLE_OFFSET
640  *
641  * Note: PREEMPT_DISABLE_OFFSET is 0 for !PREEMPT_COUNT kernels.
642  * Note: See finish_task_switch().
643  */
644 #define FORK_PREEMPT_COUNT      (2*PREEMPT_DISABLE_OFFSET + PREEMPT_ENABLED)
645 
646 /**
647  * struct thread_group_cputimer - thread group interval timer counts
648  * @cputime_atomic:     atomic thread group interval timers.
649  * @running:            true when there are timers running and
650  *                      @cputime_atomic receives updates.
651  * @checking_timer:     true when a thread in the group is in the
652  *                      process of checking for thread group timers.
653  *
654  * This structure contains the version of task_cputime, above, that is
655  * used for thread group CPU timer calculations.
656  */
657 struct thread_group_cputimer {
658         struct task_cputime_atomic cputime_atomic;
659         bool running;
660         bool checking_timer;
661 };
662 
663 #include <linux/rwsem.h>
664 struct autogroup;
665 
666 /*
667  * NOTE! "signal_struct" does not have its own
668  * locking, because a shared signal_struct always
669  * implies a shared sighand_struct, so locking
670  * sighand_struct is always a proper superset of
671  * the locking of signal_struct.
672  */
673 struct signal_struct {
674         atomic_t                sigcnt;
675         atomic_t                live;
676         int                     nr_threads;
677         struct list_head        thread_head;
678 
679         wait_queue_head_t       wait_chldexit;  /* for wait4() */
680 
681         /* current thread group signal load-balancing target: */
682         struct task_struct      *curr_target;
683 
684         /* shared signal handling: */
685         struct sigpending       shared_pending;
686 
687         /* thread group exit support */
688         int                     group_exit_code;
689         /* overloaded:
690          * - notify group_exit_task when ->count is equal to notify_count
691          * - everyone except group_exit_task is stopped during signal delivery
692          *   of fatal signals, group_exit_task processes the signal.
693          */
694         int                     notify_count;
695         struct task_struct      *group_exit_task;
696 
697         /* thread group stop support, overloads group_exit_code too */
698         int                     group_stop_count;
699         unsigned int            flags; /* see SIGNAL_* flags below */
700 
701         /*
702          * PR_SET_CHILD_SUBREAPER marks a process, like a service
703          * manager, to re-parent orphan (double-forking) child processes
704          * to this process instead of 'init'. The service manager is
705          * able to receive SIGCHLD signals and is able to investigate
706          * the process until it calls wait(). All children of this
707          * process will inherit a flag if they should look for a
708          * child_subreaper process at exit.
709          */
710         unsigned int            is_child_subreaper:1;
711         unsigned int            has_child_subreaper:1;
712 
713         /* POSIX.1b Interval Timers */
714         int                     posix_timer_id;
715         struct list_head        posix_timers;
716 
717         /* ITIMER_REAL timer for the process */
718         struct hrtimer real_timer;
719         struct pid *leader_pid;
720         ktime_t it_real_incr;
721 
722         /*
723          * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
724          * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
725          * values are defined to 0 and 1 respectively
726          */
727         struct cpu_itimer it[2];
728 
729         /*
730          * Thread group totals for process CPU timers.
731          * See thread_group_cputimer(), et al, for details.
732          */
733         struct thread_group_cputimer cputimer;
734 
735         /* Earliest-expiration cache. */
736         struct task_cputime cputime_expires;
737 
738 #ifdef CONFIG_NO_HZ_FULL
739         atomic_t tick_dep_mask;
740 #endif
741 
742         struct list_head cpu_timers[3];
743 
744         struct pid *tty_old_pgrp;
745 
746         /* boolean value for session group leader */
747         int leader;
748 
749         struct tty_struct *tty; /* NULL if no tty */
750 
751 #ifdef CONFIG_SCHED_AUTOGROUP
752         struct autogroup *autogroup;
753 #endif
754         /*
755          * Cumulative resource counters for dead threads in the group,
756          * and for reaped dead child processes forked by this group.
757          * Live threads maintain their own counters and add to these
758          * in __exit_signal, except for the group leader.
759          */
760         seqlock_t stats_lock;
761         cputime_t utime, stime, cutime, cstime;
762         cputime_t gtime;
763         cputime_t cgtime;
764         struct prev_cputime prev_cputime;
765         unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
766         unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
767         unsigned long inblock, oublock, cinblock, coublock;
768         unsigned long maxrss, cmaxrss;
769         struct task_io_accounting ioac;
770 
771         /*
772          * Cumulative ns of schedule CPU time fo dead threads in the
773          * group, not including a zombie group leader, (This only differs
774          * from jiffies_to_ns(utime + stime) if sched_clock uses something
775          * other than jiffies.)
776          */
777         unsigned long long sum_sched_runtime;
778 
779         /*
780          * We don't bother to synchronize most readers of this at all,
781          * because there is no reader checking a limit that actually needs
782          * to get both rlim_cur and rlim_max atomically, and either one
783          * alone is a single word that can safely be read normally.
784          * getrlimit/setrlimit use task_lock(current->group_leader) to
785          * protect this instead of the siglock, because they really
786          * have no need to disable irqs.
787          */
788         struct rlimit rlim[RLIM_NLIMITS];
789 
790 #ifdef CONFIG_BSD_PROCESS_ACCT
791         struct pacct_struct pacct;      /* per-process accounting information */
792 #endif
793 #ifdef CONFIG_TASKSTATS
794         struct taskstats *stats;
795 #endif
796 #ifdef CONFIG_AUDIT
797         unsigned audit_tty;
798         struct tty_audit_buf *tty_audit_buf;
799 #endif
800 
801         /*
802          * Thread is the potential origin of an oom condition; kill first on
803          * oom
804          */
805         bool oom_flag_origin;
806         short oom_score_adj;            /* OOM kill score adjustment */
807         short oom_score_adj_min;        /* OOM kill score adjustment min value.
808                                          * Only settable by CAP_SYS_RESOURCE. */
809         struct mm_struct *oom_mm;       /* recorded mm when the thread group got
810                                          * killed by the oom killer */
811 
812         struct mutex cred_guard_mutex;  /* guard against foreign influences on
813                                          * credential calculations
814                                          * (notably. ptrace) */
815 };
816 
817 /*
818  * Bits in flags field of signal_struct.
819  */
820 #define SIGNAL_STOP_STOPPED     0x00000001 /* job control stop in effect */
821 #define SIGNAL_STOP_CONTINUED   0x00000002 /* SIGCONT since WCONTINUED reap */
822 #define SIGNAL_GROUP_EXIT       0x00000004 /* group exit in progress */
823 #define SIGNAL_GROUP_COREDUMP   0x00000008 /* coredump in progress */
824 /*
825  * Pending notifications to parent.
826  */
827 #define SIGNAL_CLD_STOPPED      0x00000010
828 #define SIGNAL_CLD_CONTINUED    0x00000020
829 #define SIGNAL_CLD_MASK         (SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
830 
831 #define SIGNAL_UNKILLABLE       0x00000040 /* for init: ignore fatal signals */
832 
833 /* If true, all threads except ->group_exit_task have pending SIGKILL */
834 static inline int signal_group_exit(const struct signal_struct *sig)
835 {
836         return  (sig->flags & SIGNAL_GROUP_EXIT) ||
837                 (sig->group_exit_task != NULL);
838 }
839 
840 /*
841  * Some day this will be a full-fledged user tracking system..
842  */
843 struct user_struct {
844         atomic_t __count;       /* reference count */
845         atomic_t processes;     /* How many processes does this user have? */
846         atomic_t sigpending;    /* How many pending signals does this user have? */
847 #ifdef CONFIG_INOTIFY_USER
848         atomic_t inotify_watches; /* How many inotify watches does this user have? */
849         atomic_t inotify_devs;  /* How many inotify devs does this user have opened? */
850 #endif
851 #ifdef CONFIG_FANOTIFY
852         atomic_t fanotify_listeners;
853 #endif
854 #ifdef CONFIG_EPOLL
855         atomic_long_t epoll_watches; /* The number of file descriptors currently watched */
856 #endif
857 #ifdef CONFIG_POSIX_MQUEUE
858         /* protected by mq_lock */
859         unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */
860 #endif
861         unsigned long locked_shm; /* How many pages of mlocked shm ? */
862         unsigned long unix_inflight;    /* How many files in flight in unix sockets */
863         atomic_long_t pipe_bufs;  /* how many pages are allocated in pipe buffers */
864 
865 #ifdef CONFIG_KEYS
866         struct key *uid_keyring;        /* UID specific keyring */
867         struct key *session_keyring;    /* UID's default session keyring */
868 #endif
869 
870         /* Hash table maintenance information */
871         struct hlist_node uidhash_node;
872         kuid_t uid;
873 
874 #if defined(CONFIG_PERF_EVENTS) || defined(CONFIG_BPF_SYSCALL)
875         atomic_long_t locked_vm;
876 #endif
877 };
878 
879 extern int uids_sysfs_init(void);
880 
881 extern struct user_struct *find_user(kuid_t);
882 
883 extern struct user_struct root_user;
884 #define INIT_USER (&root_user)
885 
886 
887 struct backing_dev_info;
888 struct reclaim_state;
889 
890 #ifdef CONFIG_SCHED_INFO
891 struct sched_info {
892         /* cumulative counters */
893         unsigned long pcount;         /* # of times run on this cpu */
894         unsigned long long run_delay; /* time spent waiting on a runqueue */
895 
896         /* timestamps */
897         unsigned long long last_arrival,/* when we last ran on a cpu */
898                            last_queued; /* when we were last queued to run */
899 };
900 #endif /* CONFIG_SCHED_INFO */
901 
902 #ifdef CONFIG_TASK_DELAY_ACCT
903 struct task_delay_info {
904         spinlock_t      lock;
905         unsigned int    flags;  /* Private per-task flags */
906 
907         /* For each stat XXX, add following, aligned appropriately
908          *
909          * struct timespec XXX_start, XXX_end;
910          * u64 XXX_delay;
911          * u32 XXX_count;
912          *
913          * Atomicity of updates to XXX_delay, XXX_count protected by
914          * single lock above (split into XXX_lock if contention is an issue).
915          */
916 
917         /*
918          * XXX_count is incremented on every XXX operation, the delay
919          * associated with the operation is added to XXX_delay.
920          * XXX_delay contains the accumulated delay time in nanoseconds.
921          */
922         u64 blkio_start;        /* Shared by blkio, swapin */
923         u64 blkio_delay;        /* wait for sync block io completion */
924         u64 swapin_delay;       /* wait for swapin block io completion */
925         u32 blkio_count;        /* total count of the number of sync block */
926                                 /* io operations performed */
927         u32 swapin_count;       /* total count of the number of swapin block */
928                                 /* io operations performed */
929 
930         u64 freepages_start;
931         u64 freepages_delay;    /* wait for memory reclaim */
932         u32 freepages_count;    /* total count of memory reclaim */
933 };
934 #endif  /* CONFIG_TASK_DELAY_ACCT */
935 
936 static inline int sched_info_on(void)
937 {
938 #ifdef CONFIG_SCHEDSTATS
939         return 1;
940 #elif defined(CONFIG_TASK_DELAY_ACCT)
941         extern int delayacct_on;
942         return delayacct_on;
943 #else
944         return 0;
945 #endif
946 }
947 
948 #ifdef CONFIG_SCHEDSTATS
949 void force_schedstat_enabled(void);
950 #endif
951 
952 enum cpu_idle_type {
953         CPU_IDLE,
954         CPU_NOT_IDLE,
955         CPU_NEWLY_IDLE,
956         CPU_MAX_IDLE_TYPES
957 };
958 
959 /*
960  * Integer metrics need fixed point arithmetic, e.g., sched/fair
961  * has a few: load, load_avg, util_avg, freq, and capacity.
962  *
963  * We define a basic fixed point arithmetic range, and then formalize
964  * all these metrics based on that basic range.
965  */
966 # define SCHED_FIXEDPOINT_SHIFT 10
967 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT)
968 
969 /*
970  * Increase resolution of cpu_capacity calculations
971  */
972 #define SCHED_CAPACITY_SHIFT    SCHED_FIXEDPOINT_SHIFT
973 #define SCHED_CAPACITY_SCALE    (1L << SCHED_CAPACITY_SHIFT)
974 
975 /*
976  * Wake-queues are lists of tasks with a pending wakeup, whose
977  * callers have already marked the task as woken internally,
978  * and can thus carry on. A common use case is being able to
979  * do the wakeups once the corresponding user lock as been
980  * released.
981  *
982  * We hold reference to each task in the list across the wakeup,
983  * thus guaranteeing that the memory is still valid by the time
984  * the actual wakeups are performed in wake_up_q().
985  *
986  * One per task suffices, because there's never a need for a task to be
987  * in two wake queues simultaneously; it is forbidden to abandon a task
988  * in a wake queue (a call to wake_up_q() _must_ follow), so if a task is
989  * already in a wake queue, the wakeup will happen soon and the second
990  * waker can just skip it.
991  *
992  * The WAKE_Q macro declares and initializes the list head.
993  * wake_up_q() does NOT reinitialize the list; it's expected to be
994  * called near the end of a function, where the fact that the queue is
995  * not used again will be easy to see by inspection.
996  *
997  * Note that this can cause spurious wakeups. schedule() callers
998  * must ensure the call is done inside a loop, confirming that the
999  * wakeup condition has in fact occurred.
1000  */
1001 struct wake_q_node {
1002         struct wake_q_node *next;
1003 };
1004 
1005 struct wake_q_head {
1006         struct wake_q_node *first;
1007         struct wake_q_node **lastp;
1008 };
1009 
1010 #define WAKE_Q_TAIL ((struct wake_q_node *) 0x01)
1011 
1012 #define WAKE_Q(name)                                    \
1013         struct wake_q_head name = { WAKE_Q_TAIL, &name.first }
1014 
1015 extern void wake_q_add(struct wake_q_head *head,
1016                        struct task_struct *task);
1017 extern void wake_up_q(struct wake_q_head *head);
1018 
1019 /*
1020  * sched-domains (multiprocessor balancing) declarations:
1021  */
1022 #ifdef CONFIG_SMP
1023 #define SD_LOAD_BALANCE         0x0001  /* Do load balancing on this domain. */
1024 #define SD_BALANCE_NEWIDLE      0x0002  /* Balance when about to become idle */
1025 #define SD_BALANCE_EXEC         0x0004  /* Balance on exec */
1026 #define SD_BALANCE_FORK         0x0008  /* Balance on fork, clone */
1027 #define SD_BALANCE_WAKE         0x0010  /* Balance on wakeup */
1028 #define SD_WAKE_AFFINE          0x0020  /* Wake task to waking CPU */
1029 #define SD_ASYM_CPUCAPACITY     0x0040  /* Groups have different max cpu capacities */
1030 #define SD_SHARE_CPUCAPACITY    0x0080  /* Domain members share cpu capacity */
1031 #define SD_SHARE_POWERDOMAIN    0x0100  /* Domain members share power domain */
1032 #define SD_SHARE_PKG_RESOURCES  0x0200  /* Domain members share cpu pkg resources */
1033 #define SD_SERIALIZE            0x0400  /* Only a single load balancing instance */
1034 #define SD_ASYM_PACKING         0x0800  /* Place busy groups earlier in the domain */
1035 #define SD_PREFER_SIBLING       0x1000  /* Prefer to place tasks in a sibling domain */
1036 #define SD_OVERLAP              0x2000  /* sched_domains of this level overlap */
1037 #define SD_NUMA                 0x4000  /* cross-node balancing */
1038 
1039 #ifdef CONFIG_SCHED_SMT
1040 static inline int cpu_smt_flags(void)
1041 {
1042         return SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
1043 }
1044 #endif
1045 
1046 #ifdef CONFIG_SCHED_MC
1047 static inline int cpu_core_flags(void)
1048 {
1049         return SD_SHARE_PKG_RESOURCES;
1050 }
1051 #endif
1052 
1053 #ifdef CONFIG_NUMA
1054 static inline int cpu_numa_flags(void)
1055 {
1056         return SD_NUMA;
1057 }
1058 #endif
1059 
1060 struct sched_domain_attr {
1061         int relax_domain_level;
1062 };
1063 
1064 #define SD_ATTR_INIT    (struct sched_domain_attr) {    \
1065         .relax_domain_level = -1,                       \
1066 }
1067 
1068 extern int sched_domain_level_max;
1069 
1070 struct sched_group;
1071 
1072 struct sched_domain_shared {
1073         atomic_t        ref;
1074         atomic_t        nr_busy_cpus;
1075         int             has_idle_cores;
1076 };
1077 
1078 struct sched_domain {
1079         /* These fields must be setup */
1080         struct sched_domain *parent;    /* top domain must be null terminated */
1081         struct sched_domain *child;     /* bottom domain must be null terminated */
1082         struct sched_group *groups;     /* the balancing groups of the domain */
1083         unsigned long min_interval;     /* Minimum balance interval ms */
1084         unsigned long max_interval;     /* Maximum balance interval ms */
1085         unsigned int busy_factor;       /* less balancing by factor if busy */
1086         unsigned int imbalance_pct;     /* No balance until over watermark */
1087         unsigned int cache_nice_tries;  /* Leave cache hot tasks for # tries */
1088         unsigned int busy_idx;
1089         unsigned int idle_idx;
1090         unsigned int newidle_idx;
1091         unsigned int wake_idx;
1092         unsigned int forkexec_idx;
1093         unsigned int smt_gain;
1094 
1095         int nohz_idle;                  /* NOHZ IDLE status */
1096         int flags;                      /* See SD_* */
1097         int level;
1098 
1099         /* Runtime fields. */
1100         unsigned long last_balance;     /* init to jiffies. units in jiffies */
1101         unsigned int balance_interval;  /* initialise to 1. units in ms. */
1102         unsigned int nr_balance_failed; /* initialise to 0 */
1103 
1104         /* idle_balance() stats */
1105         u64 max_newidle_lb_cost;
1106         unsigned long next_decay_max_lb_cost;
1107 
1108         u64 avg_scan_cost;              /* select_idle_sibling */
1109 
1110 #ifdef CONFIG_SCHEDSTATS
1111         /* load_balance() stats */
1112         unsigned int lb_count[CPU_MAX_IDLE_TYPES];
1113         unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
1114         unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
1115         unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
1116         unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
1117         unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
1118         unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
1119         unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
1120 
1121         /* Active load balancing */
1122         unsigned int alb_count;
1123         unsigned int alb_failed;
1124         unsigned int alb_pushed;
1125 
1126         /* SD_BALANCE_EXEC stats */
1127         unsigned int sbe_count;
1128         unsigned int sbe_balanced;
1129         unsigned int sbe_pushed;
1130 
1131         /* SD_BALANCE_FORK stats */
1132         unsigned int sbf_count;
1133         unsigned int sbf_balanced;
1134         unsigned int sbf_pushed;
1135 
1136         /* try_to_wake_up() stats */
1137         unsigned int ttwu_wake_remote;
1138         unsigned int ttwu_move_affine;
1139         unsigned int ttwu_move_balance;
1140 #endif
1141 #ifdef CONFIG_SCHED_DEBUG
1142         char *name;
1143 #endif
1144         union {
1145                 void *private;          /* used during construction */
1146                 struct rcu_head rcu;    /* used during destruction */
1147         };
1148         struct sched_domain_shared *shared;
1149 
1150         unsigned int span_weight;
1151         /*
1152          * Span of all CPUs in this domain.
1153          *
1154          * NOTE: this field is variable length. (Allocated dynamically
1155          * by attaching extra space to the end of the structure,
1156          * depending on how many CPUs the kernel has booted up with)
1157          */
1158         unsigned long span[0];
1159 };
1160 
1161 static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
1162 {
1163         return to_cpumask(sd->span);
1164 }
1165 
1166 extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1167                                     struct sched_domain_attr *dattr_new);
1168 
1169 /* Allocate an array of sched domains, for partition_sched_domains(). */
1170 cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
1171 void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
1172 
1173 bool cpus_share_cache(int this_cpu, int that_cpu);
1174 
1175 typedef const struct cpumask *(*sched_domain_mask_f)(int cpu);
1176 typedef int (*sched_domain_flags_f)(void);
1177 
1178 #define SDTL_OVERLAP    0x01
1179 
1180 struct sd_data {
1181         struct sched_domain **__percpu sd;
1182         struct sched_domain_shared **__percpu sds;
1183         struct sched_group **__percpu sg;
1184         struct sched_group_capacity **__percpu sgc;
1185 };
1186 
1187 struct sched_domain_topology_level {
1188         sched_domain_mask_f mask;
1189         sched_domain_flags_f sd_flags;
1190         int                 flags;
1191         int                 numa_level;
1192         struct sd_data      data;
1193 #ifdef CONFIG_SCHED_DEBUG
1194         char                *name;
1195 #endif
1196 };
1197 
1198 extern void set_sched_topology(struct sched_domain_topology_level *tl);
1199 extern void wake_up_if_idle(int cpu);
1200 
1201 #ifdef CONFIG_SCHED_DEBUG
1202 # define SD_INIT_NAME(type)             .name = #type
1203 #else
1204 # define SD_INIT_NAME(type)
1205 #endif
1206 
1207 #else /* CONFIG_SMP */
1208 
1209 struct sched_domain_attr;
1210 
1211 static inline void
1212 partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1213                         struct sched_domain_attr *dattr_new)
1214 {
1215 }
1216 
1217 static inline bool cpus_share_cache(int this_cpu, int that_cpu)
1218 {
1219         return true;
1220 }
1221 
1222 #endif  /* !CONFIG_SMP */
1223 
1224 
1225 struct io_context;                      /* See blkdev.h */
1226 
1227 
1228 #ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
1229 extern void prefetch_stack(struct task_struct *t);
1230 #else
1231 static inline void prefetch_stack(struct task_struct *t) { }
1232 #endif
1233 
1234 struct audit_context;           /* See audit.c */
1235 struct mempolicy;
1236 struct pipe_inode_info;
1237 struct uts_namespace;
1238 
1239 struct load_weight {
1240         unsigned long weight;
1241         u32 inv_weight;
1242 };
1243 
1244 /*
1245  * The load_avg/util_avg accumulates an infinite geometric series
1246  * (see __update_load_avg() in kernel/sched/fair.c).
1247  *
1248  * [load_avg definition]
1249  *
1250  *   load_avg = runnable% * scale_load_down(load)
1251  *
1252  * where runnable% is the time ratio that a sched_entity is runnable.
1253  * For cfs_rq, it is the aggregated load_avg of all runnable and
1254  * blocked sched_entities.
1255  *
1256  * load_avg may also take frequency scaling into account:
1257  *
1258  *   load_avg = runnable% * scale_load_down(load) * freq%
1259  *
1260  * where freq% is the CPU frequency normalized to the highest frequency.
1261  *
1262  * [util_avg definition]
1263  *
1264  *   util_avg = running% * SCHED_CAPACITY_SCALE
1265  *
1266  * where running% is the time ratio that a sched_entity is running on
1267  * a CPU. For cfs_rq, it is the aggregated util_avg of all runnable
1268  * and blocked sched_entities.
1269  *
1270  * util_avg may also factor frequency scaling and CPU capacity scaling:
1271  *
1272  *   util_avg = running% * SCHED_CAPACITY_SCALE * freq% * capacity%
1273  *
1274  * where freq% is the same as above, and capacity% is the CPU capacity
1275  * normalized to the greatest capacity (due to uarch differences, etc).
1276  *
1277  * N.B., the above ratios (runnable%, running%, freq%, and capacity%)
1278  * themselves are in the range of [0, 1]. To do fixed point arithmetics,
1279  * we therefore scale them to as large a range as necessary. This is for
1280  * example reflected by util_avg's SCHED_CAPACITY_SCALE.
1281  *
1282  * [Overflow issue]
1283  *
1284  * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
1285  * with the highest load (=88761), always runnable on a single cfs_rq,
1286  * and should not overflow as the number already hits PID_MAX_LIMIT.
1287  *
1288  * For all other cases (including 32-bit kernels), struct load_weight's
1289  * weight will overflow first before we do, because:
1290  *
1291  *    Max(load_avg) <= Max(load.weight)
1292  *
1293  * Then it is the load_weight's responsibility to consider overflow
1294  * issues.
1295  */
1296 struct sched_avg {
1297         u64 last_update_time, load_sum;
1298         u32 util_sum, period_contrib;
1299         unsigned long load_avg, util_avg;
1300 };
1301 
1302 #ifdef CONFIG_SCHEDSTATS
1303 struct sched_statistics {
1304         u64                     wait_start;
1305         u64                     wait_max;
1306         u64                     wait_count;
1307         u64                     wait_sum;
1308         u64                     iowait_count;
1309         u64                     iowait_sum;
1310 
1311         u64                     sleep_start;
1312         u64                     sleep_max;
1313         s64                     sum_sleep_runtime;
1314 
1315         u64                     block_start;
1316         u64                     block_max;
1317         u64                     exec_max;
1318         u64                     slice_max;
1319 
1320         u64                     nr_migrations_cold;
1321         u64                     nr_failed_migrations_affine;
1322         u64                     nr_failed_migrations_running;
1323         u64                     nr_failed_migrations_hot;
1324         u64                     nr_forced_migrations;
1325 
1326         u64                     nr_wakeups;
1327         u64                     nr_wakeups_sync;
1328         u64                     nr_wakeups_migrate;
1329         u64                     nr_wakeups_local;
1330         u64                     nr_wakeups_remote;
1331         u64                     nr_wakeups_affine;
1332         u64                     nr_wakeups_affine_attempts;
1333         u64                     nr_wakeups_passive;
1334         u64                     nr_wakeups_idle;
1335 };
1336 #endif
1337 
1338 struct sched_entity {
1339         struct load_weight      load;           /* for load-balancing */
1340         struct rb_node          run_node;
1341         struct list_head        group_node;
1342         unsigned int            on_rq;
1343 
1344         u64                     exec_start;
1345         u64                     sum_exec_runtime;
1346         u64                     vruntime;
1347         u64                     prev_sum_exec_runtime;
1348 
1349         u64                     nr_migrations;
1350 
1351 #ifdef CONFIG_SCHEDSTATS
1352         struct sched_statistics statistics;
1353 #endif
1354 
1355 #ifdef CONFIG_FAIR_GROUP_SCHED
1356         int                     depth;
1357         struct sched_entity     *parent;
1358         /* rq on which this entity is (to be) queued: */
1359         struct cfs_rq           *cfs_rq;
1360         /* rq "owned" by this entity/group: */
1361         struct cfs_rq           *my_q;
1362 #endif
1363 
1364 #ifdef CONFIG_SMP
1365         /*
1366          * Per entity load average tracking.
1367          *
1368          * Put into separate cache line so it does not
1369          * collide with read-mostly values above.
1370          */
1371         struct sched_avg        avg ____cacheline_aligned_in_smp;
1372 #endif
1373 };
1374 
1375 struct sched_rt_entity {
1376         struct list_head run_list;
1377         unsigned long timeout;
1378         unsigned long watchdog_stamp;
1379         unsigned int time_slice;
1380         unsigned short on_rq;
1381         unsigned short on_list;
1382 
1383         struct sched_rt_entity *back;
1384 #ifdef CONFIG_RT_GROUP_SCHED
1385         struct sched_rt_entity  *parent;
1386         /* rq on which this entity is (to be) queued: */
1387         struct rt_rq            *rt_rq;
1388         /* rq "owned" by this entity/group: */
1389         struct rt_rq            *my_q;
1390 #endif
1391 };
1392 
1393 struct sched_dl_entity {
1394         struct rb_node  rb_node;
1395 
1396         /*
1397          * Original scheduling parameters. Copied here from sched_attr
1398          * during sched_setattr(), they will remain the same until
1399          * the next sched_setattr().
1400          */
1401         u64 dl_runtime;         /* maximum runtime for each instance    */
1402         u64 dl_deadline;        /* relative deadline of each instance   */
1403         u64 dl_period;          /* separation of two instances (period) */
1404         u64 dl_bw;              /* dl_runtime / dl_deadline             */
1405 
1406         /*
1407          * Actual scheduling parameters. Initialized with the values above,
1408          * they are continously updated during task execution. Note that
1409          * the remaining runtime could be < 0 in case we are in overrun.
1410          */
1411         s64 runtime;            /* remaining runtime for this instance  */
1412         u64 deadline;           /* absolute deadline for this instance  */
1413         unsigned int flags;     /* specifying the scheduler behaviour   */
1414 
1415         /*
1416          * Some bool flags:
1417          *
1418          * @dl_throttled tells if we exhausted the runtime. If so, the
1419          * task has to wait for a replenishment to be performed at the
1420          * next firing of dl_timer.
1421          *
1422          * @dl_boosted tells if we are boosted due to DI. If so we are
1423          * outside bandwidth enforcement mechanism (but only until we
1424          * exit the critical section);
1425          *
1426          * @dl_yielded tells if task gave up the cpu before consuming
1427          * all its available runtime during the last job.
1428          */
1429         int dl_throttled, dl_boosted, dl_yielded;
1430 
1431         /*
1432          * Bandwidth enforcement timer. Each -deadline task has its
1433          * own bandwidth to be enforced, thus we need one timer per task.
1434          */
1435         struct hrtimer dl_timer;
1436 };
1437 
1438 union rcu_special {
1439         struct {
1440                 u8 blocked;
1441                 u8 need_qs;
1442                 u8 exp_need_qs;
1443                 u8 pad; /* Otherwise the compiler can store garbage here. */
1444         } b; /* Bits. */
1445         u32 s; /* Set of bits. */
1446 };
1447 struct rcu_node;
1448 
1449 enum perf_event_task_context {
1450         perf_invalid_context = -1,
1451         perf_hw_context = 0,
1452         perf_sw_context,
1453         perf_nr_task_contexts,
1454 };
1455 
1456 /* Track pages that require TLB flushes */
1457 struct tlbflush_unmap_batch {
1458         /*
1459          * Each bit set is a CPU that potentially has a TLB entry for one of
1460          * the PFNs being flushed. See set_tlb_ubc_flush_pending().
1461          */
1462         struct cpumask cpumask;
1463 
1464         /* True if any bit in cpumask is set */
1465         bool flush_required;
1466 
1467         /*
1468          * If true then the PTE was dirty when unmapped. The entry must be
1469          * flushed before IO is initiated or a stale TLB entry potentially
1470          * allows an update without redirtying the page.
1471          */
1472         bool writable;
1473 };
1474 
1475 struct task_struct {
1476 #ifdef CONFIG_THREAD_INFO_IN_TASK
1477         /*
1478          * For reasons of header soup (see current_thread_info()), this
1479          * must be the first element of task_struct.
1480          */
1481         struct thread_info thread_info;
1482 #endif
1483         volatile long state;    /* -1 unrunnable, 0 runnable, >0 stopped */
1484         void *stack;
1485         atomic_t usage;
1486         unsigned int flags;     /* per process flags, defined below */
1487         unsigned int ptrace;
1488 
1489 #ifdef CONFIG_SMP
1490         struct llist_node wake_entry;
1491         int on_cpu;
1492 #ifdef CONFIG_THREAD_INFO_IN_TASK
1493         unsigned int cpu;       /* current CPU */
1494 #endif
1495         unsigned int wakee_flips;
1496         unsigned long wakee_flip_decay_ts;
1497         struct task_struct *last_wakee;
1498 
1499         int wake_cpu;
1500 #endif
1501         int on_rq;
1502 
1503         int prio, static_prio, normal_prio;
1504         unsigned int rt_priority;
1505         const struct sched_class *sched_class;
1506         struct sched_entity se;
1507         struct sched_rt_entity rt;
1508 #ifdef CONFIG_CGROUP_SCHED
1509         struct task_group *sched_task_group;
1510 #endif
1511         struct sched_dl_entity dl;
1512 
1513 #ifdef CONFIG_PREEMPT_NOTIFIERS
1514         /* list of struct preempt_notifier: */
1515         struct hlist_head preempt_notifiers;
1516 #endif
1517 
1518 #ifdef CONFIG_BLK_DEV_IO_TRACE
1519         unsigned int btrace_seq;
1520 #endif
1521 
1522         unsigned int policy;
1523         int nr_cpus_allowed;
1524         cpumask_t cpus_allowed;
1525 
1526 #ifdef CONFIG_PREEMPT_RCU
1527         int rcu_read_lock_nesting;
1528         union rcu_special rcu_read_unlock_special;
1529         struct list_head rcu_node_entry;
1530         struct rcu_node *rcu_blocked_node;
1531 #endif /* #ifdef CONFIG_PREEMPT_RCU */
1532 #ifdef CONFIG_TASKS_RCU
1533         unsigned long rcu_tasks_nvcsw;
1534         bool rcu_tasks_holdout;
1535         struct list_head rcu_tasks_holdout_list;
1536         int rcu_tasks_idle_cpu;
1537 #endif /* #ifdef CONFIG_TASKS_RCU */
1538 
1539 #ifdef CONFIG_SCHED_INFO
1540         struct sched_info sched_info;
1541 #endif
1542 
1543         struct list_head tasks;
1544 #ifdef CONFIG_SMP
1545         struct plist_node pushable_tasks;
1546         struct rb_node pushable_dl_tasks;
1547 #endif
1548 
1549         struct mm_struct *mm, *active_mm;
1550         /* per-thread vma caching */
1551         u32 vmacache_seqnum;
1552         struct vm_area_struct *vmacache[VMACACHE_SIZE];
1553 #if defined(SPLIT_RSS_COUNTING)
1554         struct task_rss_stat    rss_stat;
1555 #endif
1556 /* task state */
1557         int exit_state;
1558         int exit_code, exit_signal;
1559         int pdeath_signal;  /*  The signal sent when the parent dies  */
1560         unsigned long jobctl;   /* JOBCTL_*, siglock protected */
1561 
1562         /* Used for emulating ABI behavior of previous Linux versions */
1563         unsigned int personality;
1564 
1565         /* scheduler bits, serialized by scheduler locks */
1566         unsigned sched_reset_on_fork:1;
1567         unsigned sched_contributes_to_load:1;
1568         unsigned sched_migrated:1;
1569         unsigned sched_remote_wakeup:1;
1570         unsigned :0; /* force alignment to the next boundary */
1571 
1572         /* unserialized, strictly 'current' */
1573         unsigned in_execve:1; /* bit to tell LSMs we're in execve */
1574         unsigned in_iowait:1;
1575 #if !defined(TIF_RESTORE_SIGMASK)
1576         unsigned restore_sigmask:1;
1577 #endif
1578 #ifdef CONFIG_MEMCG
1579         unsigned memcg_may_oom:1;
1580 #ifndef CONFIG_SLOB
1581         unsigned memcg_kmem_skip_account:1;
1582 #endif
1583 #endif
1584 #ifdef CONFIG_COMPAT_BRK
1585         unsigned brk_randomized:1;
1586 #endif
1587 
1588         unsigned long atomic_flags; /* Flags needing atomic access. */
1589 
1590         struct restart_block restart_block;
1591 
1592         pid_t pid;
1593         pid_t tgid;
1594 
1595 #ifdef CONFIG_CC_STACKPROTECTOR
1596         /* Canary value for the -fstack-protector gcc feature */
1597         unsigned long stack_canary;
1598 #endif
1599         /*
1600          * pointers to (original) parent process, youngest child, younger sibling,
1601          * older sibling, respectively.  (p->father can be replaced with
1602          * p->real_parent->pid)
1603          */
1604         struct task_struct __rcu *real_parent; /* real parent process */
1605         struct task_struct __rcu *parent; /* recipient of SIGCHLD, wait4() reports */
1606         /*
1607          * children/sibling forms the list of my natural children
1608          */
1609         struct list_head children;      /* list of my children */
1610         struct list_head sibling;       /* linkage in my parent's children list */
1611         struct task_struct *group_leader;       /* threadgroup leader */
1612 
1613         /*
1614          * ptraced is the list of tasks this task is using ptrace on.
1615          * This includes both natural children and PTRACE_ATTACH targets.
1616          * p->ptrace_entry is p's link on the p->parent->ptraced list.
1617          */
1618         struct list_head ptraced;
1619         struct list_head ptrace_entry;
1620 
1621         /* PID/PID hash table linkage. */
1622         struct pid_link pids[PIDTYPE_MAX];
1623         struct list_head thread_group;
1624         struct list_head thread_node;
1625 
1626         struct completion *vfork_done;          /* for vfork() */
1627         int __user *set_child_tid;              /* CLONE_CHILD_SETTID */
1628         int __user *clear_child_tid;            /* CLONE_CHILD_CLEARTID */
1629 
1630         cputime_t utime, stime, utimescaled, stimescaled;
1631         cputime_t gtime;
1632         struct prev_cputime prev_cputime;
1633 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1634         seqcount_t vtime_seqcount;
1635         unsigned long long vtime_snap;
1636         enum {
1637                 /* Task is sleeping or running in a CPU with VTIME inactive */
1638                 VTIME_INACTIVE = 0,
1639                 /* Task runs in userspace in a CPU with VTIME active */
1640                 VTIME_USER,
1641                 /* Task runs in kernelspace in a CPU with VTIME active */
1642                 VTIME_SYS,
1643         } vtime_snap_whence;
1644 #endif
1645 
1646 #ifdef CONFIG_NO_HZ_FULL
1647         atomic_t tick_dep_mask;
1648 #endif
1649         unsigned long nvcsw, nivcsw; /* context switch counts */
1650         u64 start_time;         /* monotonic time in nsec */
1651         u64 real_start_time;    /* boot based time in nsec */
1652 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1653         unsigned long min_flt, maj_flt;
1654 
1655         struct task_cputime cputime_expires;
1656         struct list_head cpu_timers[3];
1657 
1658 /* process credentials */
1659         const struct cred __rcu *real_cred; /* objective and real subjective task
1660                                          * credentials (COW) */
1661         const struct cred __rcu *cred;  /* effective (overridable) subjective task
1662                                          * credentials (COW) */
1663         char comm[TASK_COMM_LEN]; /* executable name excluding path
1664                                      - access with [gs]et_task_comm (which lock
1665                                        it with task_lock())
1666                                      - initialized normally by setup_new_exec */
1667 /* file system info */
1668         struct nameidata *nameidata;
1669 #ifdef CONFIG_SYSVIPC
1670 /* ipc stuff */
1671         struct sysv_sem sysvsem;
1672         struct sysv_shm sysvshm;
1673 #endif
1674 #ifdef CONFIG_DETECT_HUNG_TASK
1675 /* hung task detection */
1676         unsigned long last_switch_count;
1677 #endif
1678 /* filesystem information */
1679         struct fs_struct *fs;
1680 /* open file information */
1681         struct files_struct *files;
1682 /* namespaces */
1683         struct nsproxy *nsproxy;
1684 /* signal handlers */
1685         struct signal_struct *signal;
1686         struct sighand_struct *sighand;
1687 
1688         sigset_t blocked, real_blocked;
1689         sigset_t saved_sigmask; /* restored if set_restore_sigmask() was used */
1690         struct sigpending pending;
1691 
1692         unsigned long sas_ss_sp;
1693         size_t sas_ss_size;
1694         unsigned sas_ss_flags;
1695 
1696         struct callback_head *task_works;
1697 
1698         struct audit_context *audit_context;
1699 #ifdef CONFIG_AUDITSYSCALL
1700         kuid_t loginuid;
1701         unsigned int sessionid;
1702 #endif
1703         struct seccomp seccomp;
1704 
1705 /* Thread group tracking */
1706         u32 parent_exec_id;
1707         u32 self_exec_id;
1708 /* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1709  * mempolicy */
1710         spinlock_t alloc_lock;
1711 
1712         /* Protection of the PI data structures: */
1713         raw_spinlock_t pi_lock;
1714 
1715         struct wake_q_node wake_q;
1716 
1717 #ifdef CONFIG_RT_MUTEXES
1718         /* PI waiters blocked on a rt_mutex held by this task */
1719         struct rb_root pi_waiters;
1720         struct rb_node *pi_waiters_leftmost;
1721         /* Deadlock detection and priority inheritance handling */
1722         struct rt_mutex_waiter *pi_blocked_on;
1723 #endif
1724 
1725 #ifdef CONFIG_DEBUG_MUTEXES
1726         /* mutex deadlock detection */
1727         struct mutex_waiter *blocked_on;
1728 #endif
1729 #ifdef CONFIG_TRACE_IRQFLAGS
1730         unsigned int irq_events;
1731         unsigned long hardirq_enable_ip;
1732         unsigned long hardirq_disable_ip;
1733         unsigned int hardirq_enable_event;
1734         unsigned int hardirq_disable_event;
1735         int hardirqs_enabled;
1736         int hardirq_context;
1737         unsigned long softirq_disable_ip;
1738         unsigned long softirq_enable_ip;
1739         unsigned int softirq_disable_event;
1740         unsigned int softirq_enable_event;
1741         int softirqs_enabled;
1742         int softirq_context;
1743 #endif
1744 #ifdef CONFIG_LOCKDEP
1745 # define MAX_LOCK_DEPTH 48UL
1746         u64 curr_chain_key;
1747         int lockdep_depth;
1748         unsigned int lockdep_recursion;
1749         struct held_lock held_locks[MAX_LOCK_DEPTH];
1750         gfp_t lockdep_reclaim_gfp;
1751 #endif
1752 #ifdef CONFIG_UBSAN
1753         unsigned int in_ubsan;
1754 #endif
1755 
1756 /* journalling filesystem info */
1757         void *journal_info;
1758 
1759 /* stacked block device info */
1760         struct bio_list *bio_list;
1761 
1762 #ifdef CONFIG_BLOCK
1763 /* stack plugging */
1764         struct blk_plug *plug;
1765 #endif
1766 
1767 /* VM state */
1768         struct reclaim_state *reclaim_state;
1769 
1770         struct backing_dev_info *backing_dev_info;
1771 
1772         struct io_context *io_context;
1773 
1774         unsigned long ptrace_message;
1775         siginfo_t *last_siginfo; /* For ptrace use.  */
1776         struct task_io_accounting ioac;
1777 #if defined(CONFIG_TASK_XACCT)
1778         u64 acct_rss_mem1;      /* accumulated rss usage */
1779         u64 acct_vm_mem1;       /* accumulated virtual memory usage */
1780         cputime_t acct_timexpd; /* stime + utime since last update */
1781 #endif
1782 #ifdef CONFIG_CPUSETS
1783         nodemask_t mems_allowed;        /* Protected by alloc_lock */
1784         seqcount_t mems_allowed_seq;    /* Seqence no to catch updates */
1785         int cpuset_mem_spread_rotor;
1786         int cpuset_slab_spread_rotor;
1787 #endif
1788 #ifdef CONFIG_CGROUPS
1789         /* Control Group info protected by css_set_lock */
1790         struct css_set __rcu *cgroups;
1791         /* cg_list protected by css_set_lock and tsk->alloc_lock */
1792         struct list_head cg_list;
1793 #endif
1794 #ifdef CONFIG_FUTEX
1795         struct robust_list_head __user *robust_list;
1796 #ifdef CONFIG_COMPAT
1797         struct compat_robust_list_head __user *compat_robust_list;
1798 #endif
1799         struct list_head pi_state_list;
1800         struct futex_pi_state *pi_state_cache;
1801 #endif
1802 #ifdef CONFIG_PERF_EVENTS
1803         struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1804         struct mutex perf_event_mutex;
1805         struct list_head perf_event_list;
1806 #endif
1807 #ifdef CONFIG_DEBUG_PREEMPT
1808         unsigned long preempt_disable_ip;
1809 #endif
1810 #ifdef CONFIG_NUMA
1811         struct mempolicy *mempolicy;    /* Protected by alloc_lock */
1812         short il_next;
1813         short pref_node_fork;
1814 #endif
1815 #ifdef CONFIG_NUMA_BALANCING
1816         int numa_scan_seq;
1817         unsigned int numa_scan_period;
1818         unsigned int numa_scan_period_max;
1819         int numa_preferred_nid;
1820         unsigned long numa_migrate_retry;
1821         u64 node_stamp;                 /* migration stamp  */
1822         u64 last_task_numa_placement;
1823         u64 last_sum_exec_runtime;
1824         struct callback_head numa_work;
1825 
1826         struct list_head numa_entry;
1827         struct numa_group *numa_group;
1828 
1829         /*
1830          * numa_faults is an array split into four regions:
1831          * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1832          * in this precise order.
1833          *
1834          * faults_memory: Exponential decaying average of faults on a per-node
1835          * basis. Scheduling placement decisions are made based on these
1836          * counts. The values remain static for the duration of a PTE scan.
1837          * faults_cpu: Track the nodes the process was running on when a NUMA
1838          * hinting fault was incurred.
1839          * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1840          * during the current scan window. When the scan completes, the counts
1841          * in faults_memory and faults_cpu decay and these values are copied.
1842          */
1843         unsigned long *numa_faults;
1844         unsigned long total_numa_faults;
1845 
1846         /*
1847          * numa_faults_locality tracks if faults recorded during the last
1848          * scan window were remote/local or failed to migrate. The task scan
1849          * period is adapted based on the locality of the faults with different
1850          * weights depending on whether they were shared or private faults
1851          */
1852         unsigned long numa_faults_locality[3];
1853 
1854         unsigned long numa_pages_migrated;
1855 #endif /* CONFIG_NUMA_BALANCING */
1856 
1857 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
1858         struct tlbflush_unmap_batch tlb_ubc;
1859 #endif
1860 
1861         struct rcu_head rcu;
1862 
1863         /*
1864          * cache last used pipe for splice
1865          */
1866         struct pipe_inode_info *splice_pipe;
1867 
1868         struct page_frag task_frag;
1869 
1870 #ifdef  CONFIG_TASK_DELAY_ACCT
1871         struct task_delay_info *delays;
1872 #endif
1873 #ifdef CONFIG_FAULT_INJECTION
1874         int make_it_fail;
1875 #endif
1876         /*
1877          * when (nr_dirtied >= nr_dirtied_pause), it's time to call
1878          * balance_dirty_pages() for some dirty throttling pause
1879          */
1880         int nr_dirtied;
1881         int nr_dirtied_pause;
1882         unsigned long dirty_paused_when; /* start of a write-and-pause period */
1883 
1884 #ifdef CONFIG_LATENCYTOP
1885         int latency_record_count;
1886         struct latency_record latency_record[LT_SAVECOUNT];
1887 #endif
1888         /*
1889          * time slack values; these are used to round up poll() and
1890          * select() etc timeout values. These are in nanoseconds.
1891          */
1892         u64 timer_slack_ns;
1893         u64 default_timer_slack_ns;
1894 
1895 #ifdef CONFIG_KASAN
1896         unsigned int kasan_depth;
1897 #endif
1898 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1899         /* Index of current stored address in ret_stack */
1900         int curr_ret_stack;
1901         /* Stack of return addresses for return function tracing */
1902         struct ftrace_ret_stack *ret_stack;
1903         /* time stamp for last schedule */
1904         unsigned long long ftrace_timestamp;
1905         /*
1906          * Number of functions that haven't been traced
1907          * because of depth overrun.
1908          */
1909         atomic_t trace_overrun;
1910         /* Pause for the tracing */
1911         atomic_t tracing_graph_pause;
1912 #endif
1913 #ifdef CONFIG_TRACING
1914         /* state flags for use by tracers */
1915         unsigned long trace;
1916         /* bitmask and counter of trace recursion */
1917         unsigned long trace_recursion;
1918 #endif /* CONFIG_TRACING */
1919 #ifdef CONFIG_KCOV
1920         /* Coverage collection mode enabled for this task (0 if disabled). */
1921         enum kcov_mode kcov_mode;
1922         /* Size of the kcov_area. */
1923         unsigned        kcov_size;
1924         /* Buffer for coverage collection. */
1925         void            *kcov_area;
1926         /* kcov desciptor wired with this task or NULL. */
1927         struct kcov     *kcov;
1928 #endif
1929 #ifdef CONFIG_MEMCG
1930         struct mem_cgroup *memcg_in_oom;
1931         gfp_t memcg_oom_gfp_mask;
1932         int memcg_oom_order;
1933 
1934         /* number of pages to reclaim on returning to userland */
1935         unsigned int memcg_nr_pages_over_high;
1936 #endif
1937 #ifdef CONFIG_UPROBES
1938         struct uprobe_task *utask;
1939 #endif
1940 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1941         unsigned int    sequential_io;
1942         unsigned int    sequential_io_avg;
1943 #endif
1944 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1945         unsigned long   task_state_change;
1946 #endif
1947         int pagefault_disabled;
1948 #ifdef CONFIG_MMU
1949         struct task_struct *oom_reaper_list;
1950 #endif
1951 #ifdef CONFIG_VMAP_STACK
1952         struct vm_struct *stack_vm_area;
1953 #endif
1954 #ifdef CONFIG_THREAD_INFO_IN_TASK
1955         /* A live task holds one reference. */
1956         atomic_t stack_refcount;
1957 #endif
1958 /* CPU-specific state of this task */
1959         struct thread_struct thread;
1960 /*
1961  * WARNING: on x86, 'thread_struct' contains a variable-sized
1962  * structure.  It *MUST* be at the end of 'task_struct'.
1963  *
1964  * Do not put anything below here!
1965  */
1966 };
1967 
1968 #ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
1969 extern int arch_task_struct_size __read_mostly;
1970 #else
1971 # define arch_task_struct_size (sizeof(struct task_struct))
1972 #endif
1973 
1974 #ifdef CONFIG_VMAP_STACK
1975 static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
1976 {
1977         return t->stack_vm_area;
1978 }
1979 #else
1980 static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
1981 {
1982         return NULL;
1983 }
1984 #endif
1985 
1986 /* Future-safe accessor for struct task_struct's cpus_allowed. */
1987 #define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
1988 
1989 static inline int tsk_nr_cpus_allowed(struct task_struct *p)
1990 {
1991         return p->nr_cpus_allowed;
1992 }
1993 
1994 #define TNF_MIGRATED    0x01
1995 #define TNF_NO_GROUP    0x02
1996 #define TNF_SHARED      0x04
1997 #define TNF_FAULT_LOCAL 0x08
1998 #define TNF_MIGRATE_FAIL 0x10
1999 
2000 static inline bool in_vfork(struct task_struct *tsk)
2001 {
2002         bool ret;
2003 
2004         /*
2005          * need RCU to access ->real_parent if CLONE_VM was used along with
2006          * CLONE_PARENT.
2007          *
2008          * We check real_parent->mm == tsk->mm because CLONE_VFORK does not
2009          * imply CLONE_VM
2010          *
2011          * CLONE_VFORK can be used with CLONE_PARENT/CLONE_THREAD and thus
2012          * ->real_parent is not necessarily the task doing vfork(), so in
2013          * theory we can't rely on task_lock() if we want to dereference it.
2014          *
2015          * And in this case we can't trust the real_parent->mm == tsk->mm
2016          * check, it can be false negative. But we do not care, if init or
2017          * another oom-unkillable task does this it should blame itself.
2018          */
2019         rcu_read_lock();
2020         ret = tsk->vfork_done && tsk->real_parent->mm == tsk->mm;
2021         rcu_read_unlock();
2022 
2023         return ret;
2024 }
2025 
2026 #ifdef CONFIG_NUMA_BALANCING
2027 extern void task_numa_fault(int last_node, int node, int pages, int flags);
2028 extern pid_t task_numa_group_id(struct task_struct *p);
2029 extern void set_numabalancing_state(bool enabled);
2030 extern void task_numa_free(struct task_struct *p);
2031 extern bool should_numa_migrate_memory(struct task_struct *p, struct page *page,
2032                                         int src_nid, int dst_cpu);
2033 #else
2034 static inline void task_numa_fault(int last_node, int node, int pages,
2035                                    int flags)
2036 {
2037 }
2038 static inline pid_t task_numa_group_id(struct task_struct *p)
2039 {
2040         return 0;
2041 }
2042 static inline void set_numabalancing_state(bool enabled)
2043 {
2044 }
2045 static inline void task_numa_free(struct task_struct *p)
2046 {
2047 }
2048 static inline bool should_numa_migrate_memory(struct task_struct *p,
2049                                 struct page *page, int src_nid, int dst_cpu)
2050 {
2051         return true;
2052 }
2053 #endif
2054 
2055 static inline struct pid *task_pid(struct task_struct *task)
2056 {
2057         return task->pids[PIDTYPE_PID].pid;
2058 }
2059 
2060 static inline struct pid *task_tgid(struct task_struct *task)
2061 {
2062         return task->group_leader->pids[PIDTYPE_PID].pid;
2063 }
2064 
2065 /*
2066  * Without tasklist or rcu lock it is not safe to dereference
2067  * the result of task_pgrp/task_session even if task == current,
2068  * we can race with another thread doing sys_setsid/sys_setpgid.
2069  */
2070 static inline struct pid *task_pgrp(struct task_struct *task)
2071 {
2072         return task->group_leader->pids[PIDTYPE_PGID].pid;
2073 }
2074 
2075 static inline struct pid *task_session(struct task_struct *task)
2076 {
2077         return task->group_leader->pids[PIDTYPE_SID].pid;
2078 }
2079 
2080 struct pid_namespace;
2081 
2082 /*
2083  * the helpers to get the task's different pids as they are seen
2084  * from various namespaces
2085  *
2086  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
2087  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
2088  *                     current.
2089  * task_xid_nr_ns()  : id seen from the ns specified;
2090  *
2091  * set_task_vxid()   : assigns a virtual id to a task;
2092  *
2093  * see also pid_nr() etc in include/linux/pid.h
2094  */
2095 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
2096                         struct pid_namespace *ns);
2097 
2098 static inline pid_t task_pid_nr(struct task_struct *tsk)
2099 {
2100         return tsk->pid;
2101 }
2102 
2103 static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
2104                                         struct pid_namespace *ns)
2105 {
2106         return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
2107 }
2108 
2109 static inline pid_t task_pid_vnr(struct task_struct *tsk)
2110 {
2111         return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
2112 }
2113 
2114 
2115 static inline pid_t task_tgid_nr(struct task_struct *tsk)
2116 {
2117         return tsk->tgid;
2118 }
2119 
2120 pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
2121 
2122 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
2123 {
2124         return pid_vnr(task_tgid(tsk));
2125 }
2126 
2127 
2128 static inline int pid_alive(const struct task_struct *p);
2129 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
2130 {
2131         pid_t pid = 0;
2132 
2133         rcu_read_lock();
2134         if (pid_alive(tsk))
2135                 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
2136         rcu_read_unlock();
2137 
2138         return pid;
2139 }
2140 
2141 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
2142 {
2143         return task_ppid_nr_ns(tsk, &init_pid_ns);
2144 }
2145 
2146 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
2147                                         struct pid_namespace *ns)
2148 {
2149         return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
2150 }
2151 
2152 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
2153 {
2154         return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
2155 }
2156 
2157 
2158 static inline pid_t task_session_nr_ns(struct task_struct *tsk,
2159                                         struct pid_namespace *ns)
2160 {
2161         return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
2162 }
2163 
2164 static inline pid_t task_session_vnr(struct task_struct *tsk)
2165 {
2166         return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
2167 }
2168 
2169 /* obsolete, do not use */
2170 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
2171 {
2172         return task_pgrp_nr_ns(tsk, &init_pid_ns);
2173 }
2174 
2175 /**
2176  * pid_alive - check that a task structure is not stale
2177  * @p: Task structure to be checked.
2178  *
2179  * Test if a process is not yet dead (at most zombie state)
2180  * If pid_alive fails, then pointers within the task structure
2181  * can be stale and must not be dereferenced.
2182  *
2183  * Return: 1 if the process is alive. 0 otherwise.
2184  */
2185 static inline int pid_alive(const struct task_struct *p)
2186 {
2187         return p->pids[PIDTYPE_PID].pid != NULL;
2188 }
2189 
2190 /**
2191  * is_global_init - check if a task structure is init. Since init
2192  * is free to have sub-threads we need to check tgid.
2193  * @tsk: Task structure to be checked.
2194  *
2195  * Check if a task structure is the first user space task the kernel created.
2196  *
2197  * Return: 1 if the task structure is init. 0 otherwise.
2198  */
2199 static inline int is_global_init(struct task_struct *tsk)
2200 {
2201         return task_tgid_nr(tsk) == 1;
2202 }
2203 
2204 extern struct pid *cad_pid;
2205 
2206 extern void free_task(struct task_struct *tsk);
2207 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
2208 
2209 extern void __put_task_struct(struct task_struct *t);
2210 
2211 static inline void put_task_struct(struct task_struct *t)
2212 {
2213         if (atomic_dec_and_test(&t->usage))
2214                 __put_task_struct(t);
2215 }
2216 
2217 struct task_struct *task_rcu_dereference(struct task_struct **ptask);
2218 struct task_struct *try_get_task_struct(struct task_struct **ptask);
2219 
2220 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
2221 extern void task_cputime(struct task_struct *t,
2222                          cputime_t *utime, cputime_t *stime);
2223 extern void task_cputime_scaled(struct task_struct *t,
2224                                 cputime_t *utimescaled, cputime_t *stimescaled);
2225 extern cputime_t task_gtime(struct task_struct *t);
2226 #else
2227 static inline void task_cputime(struct task_struct *t,
2228                                 cputime_t *utime, cputime_t *stime)
2229 {
2230         if (utime)
2231                 *utime = t->utime;
2232         if (stime)
2233                 *stime = t->stime;
2234 }
2235 
2236 static inline void task_cputime_scaled(struct task_struct *t,
2237                                        cputime_t *utimescaled,
2238                                        cputime_t *stimescaled)
2239 {
2240         if (utimescaled)
2241                 *utimescaled = t->utimescaled;
2242         if (stimescaled)
2243                 *stimescaled = t->stimescaled;
2244 }
2245 
2246 static inline cputime_t task_gtime(struct task_struct *t)
2247 {
2248         return t->gtime;
2249 }
2250 #endif
2251 extern void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
2252 extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
2253 
2254 /*
2255  * Per process flags
2256  */
2257 #define PF_EXITING      0x00000004      /* getting shut down */
2258 #define PF_EXITPIDONE   0x00000008      /* pi exit done on shut down */
2259 #define PF_VCPU         0x00000010      /* I'm a virtual CPU */
2260 #define PF_WQ_WORKER    0x00000020      /* I'm a workqueue worker */
2261 #define PF_FORKNOEXEC   0x00000040      /* forked but didn't exec */
2262 #define PF_MCE_PROCESS  0x00000080      /* process policy on mce errors */
2263 #define PF_SUPERPRIV    0x00000100      /* used super-user privileges */
2264 #define PF_DUMPCORE     0x00000200      /* dumped core */
2265 #define PF_SIGNALED     0x00000400      /* killed by a signal */
2266 #define PF_MEMALLOC     0x00000800      /* Allocating memory */
2267 #define PF_NPROC_EXCEEDED 0x00001000    /* set_user noticed that RLIMIT_NPROC was exceeded */
2268 #define PF_USED_MATH    0x00002000      /* if unset the fpu must be initialized before use */
2269 #define PF_USED_ASYNC   0x00004000      /* used async_schedule*(), used by module init */
2270 #define PF_NOFREEZE     0x00008000      /* this thread should not be frozen */
2271 #define PF_FROZEN       0x00010000      /* frozen for system suspend */
2272 #define PF_FSTRANS      0x00020000      /* inside a filesystem transaction */
2273 #define PF_KSWAPD       0x00040000      /* I am kswapd */
2274 #define PF_MEMALLOC_NOIO 0x00080000     /* Allocating memory without IO involved */
2275 #define PF_LESS_THROTTLE 0x00100000     /* Throttle me less: I clean memory */
2276 #define PF_KTHREAD      0x00200000      /* I am a kernel thread */
2277 #define PF_RANDOMIZE    0x00400000      /* randomize virtual address space */
2278 #define PF_SWAPWRITE    0x00800000      /* Allowed to write to swap */
2279 #define PF_NO_SETAFFINITY 0x04000000    /* Userland is not allowed to meddle with cpus_allowed */
2280 #define PF_MCE_EARLY    0x08000000      /* Early kill for mce process policy */
2281 #define PF_MUTEX_TESTER 0x20000000      /* Thread belongs to the rt mutex tester */
2282 #define PF_FREEZER_SKIP 0x40000000      /* Freezer should not count it as freezable */
2283 #define PF_SUSPEND_TASK 0x80000000      /* this thread called freeze_processes and should not be frozen */
2284 
2285 /*
2286  * Only the _current_ task can read/write to tsk->flags, but other
2287  * tasks can access tsk->flags in readonly mode for example
2288  * with tsk_used_math (like during threaded core dumping).
2289  * There is however an exception to this rule during ptrace
2290  * or during fork: the ptracer task is allowed to write to the
2291  * child->flags of its traced child (same goes for fork, the parent
2292  * can write to the child->flags), because we're guaranteed the
2293  * child is not running and in turn not changing child->flags
2294  * at the same time the parent does it.
2295  */
2296 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
2297 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
2298 #define clear_used_math() clear_stopped_child_used_math(current)
2299 #define set_used_math() set_stopped_child_used_math(current)
2300 #define conditional_stopped_child_used_math(condition, child) \
2301         do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
2302 #define conditional_used_math(condition) \
2303         conditional_stopped_child_used_math(condition, current)
2304 #define copy_to_stopped_child_used_math(child) \
2305         do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
2306 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
2307 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
2308 #define used_math() tsk_used_math(current)
2309 
2310 /* __GFP_IO isn't allowed if PF_MEMALLOC_NOIO is set in current->flags
2311  * __GFP_FS is also cleared as it implies __GFP_IO.
2312  */
2313 static inline gfp_t memalloc_noio_flags(gfp_t flags)
2314 {
2315         if (unlikely(current->flags & PF_MEMALLOC_NOIO))
2316                 flags &= ~(__GFP_IO | __GFP_FS);
2317         return flags;
2318 }
2319 
2320 static inline unsigned int memalloc_noio_save(void)
2321 {
2322         unsigned int flags = current->flags & PF_MEMALLOC_NOIO;
2323         current->flags |= PF_MEMALLOC_NOIO;
2324         return flags;
2325 }
2326 
2327 static inline void memalloc_noio_restore(unsigned int flags)
2328 {
2329         current->flags = (current->flags & ~PF_MEMALLOC_NOIO) | flags;
2330 }
2331 
2332 /* Per-process atomic flags. */
2333 #define PFA_NO_NEW_PRIVS 0      /* May not gain new privileges. */
2334 #define PFA_SPREAD_PAGE  1      /* Spread page cache over cpuset */
2335 #define PFA_SPREAD_SLAB  2      /* Spread some slab caches over cpuset */
2336 #define PFA_LMK_WAITING  3      /* Lowmemorykiller is waiting */
2337 
2338 
2339 #define TASK_PFA_TEST(name, func)                                       \
2340         static inline bool task_##func(struct task_struct *p)           \
2341         { return test_bit(PFA_##name, &p->atomic_flags); }
2342 #define TASK_PFA_SET(name, func)                                        \
2343         static inline void task_set_##func(struct task_struct *p)       \
2344         { set_bit(PFA_##name, &p->atomic_flags); }
2345 #define TASK_PFA_CLEAR(name, func)                                      \
2346         static inline void task_clear_##func(struct task_struct *p)     \
2347         { clear_bit(PFA_##name, &p->atomic_flags); }
2348 
2349 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
2350 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
2351 
2352 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
2353 TASK_PFA_SET(SPREAD_PAGE, spread_page)
2354 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
2355 
2356 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
2357 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
2358 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
2359 
2360 TASK_PFA_TEST(LMK_WAITING, lmk_waiting)
2361 TASK_PFA_SET(LMK_WAITING, lmk_waiting)
2362 
2363 /*
2364  * task->jobctl flags
2365  */
2366 #define JOBCTL_STOP_SIGMASK     0xffff  /* signr of the last group stop */
2367 
2368 #define JOBCTL_STOP_DEQUEUED_BIT 16     /* stop signal dequeued */
2369 #define JOBCTL_STOP_PENDING_BIT 17      /* task should stop for group stop */
2370 #define JOBCTL_STOP_CONSUME_BIT 18      /* consume group stop count */
2371 #define JOBCTL_TRAP_STOP_BIT    19      /* trap for STOP */
2372 #define JOBCTL_TRAP_NOTIFY_BIT  20      /* trap for NOTIFY */
2373 #define JOBCTL_TRAPPING_BIT     21      /* switching to TRACED */
2374 #define JOBCTL_LISTENING_BIT    22      /* ptracer is listening for events */
2375 
2376 #define JOBCTL_STOP_DEQUEUED    (1UL << JOBCTL_STOP_DEQUEUED_BIT)
2377 #define JOBCTL_STOP_PENDING     (1UL << JOBCTL_STOP_PENDING_BIT)
2378 #define JOBCTL_STOP_CONSUME     (1UL << JOBCTL_STOP_CONSUME_BIT)
2379 #define JOBCTL_TRAP_STOP        (1UL << JOBCTL_TRAP_STOP_BIT)
2380 #define JOBCTL_TRAP_NOTIFY      (1UL << JOBCTL_TRAP_NOTIFY_BIT)
2381 #define JOBCTL_TRAPPING         (1UL << JOBCTL_TRAPPING_BIT)
2382 #define JOBCTL_LISTENING        (1UL << JOBCTL_LISTENING_BIT)
2383 
2384 #define JOBCTL_TRAP_MASK        (JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
2385 #define JOBCTL_PENDING_MASK     (JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)
2386 
2387 extern bool task_set_jobctl_pending(struct task_struct *task,
2388                                     unsigned long mask);
2389 extern void task_clear_jobctl_trapping(struct task_struct *task);
2390 extern void task_clear_jobctl_pending(struct task_struct *task,
2391                                       unsigned long mask);
2392 
2393 static inline void rcu_copy_process(struct task_struct *p)
2394 {
2395 #ifdef CONFIG_PREEMPT_RCU
2396         p->rcu_read_lock_nesting = 0;
2397         p->rcu_read_unlock_special.s = 0;
2398         p->rcu_blocked_node = NULL;
2399         INIT_LIST_HEAD(&p->rcu_node_entry);
2400 #endif /* #ifdef CONFIG_PREEMPT_RCU */
2401 #ifdef CONFIG_TASKS_RCU
2402         p->rcu_tasks_holdout = false;
2403         INIT_LIST_HEAD(&p->rcu_tasks_holdout_list);
2404         p->rcu_tasks_idle_cpu = -1;
2405 #endif /* #ifdef CONFIG_TASKS_RCU */
2406 }
2407 
2408 static inline void tsk_restore_flags(struct task_struct *task,
2409                                 unsigned long orig_flags, unsigned long flags)
2410 {
2411         task->flags &= ~flags;
2412         task->flags |= orig_flags & flags;
2413 }
2414 
2415 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur,
2416                                      const struct cpumask *trial);
2417 extern int task_can_attach(struct task_struct *p,
2418                            const struct cpumask *cs_cpus_allowed);
2419 #ifdef CONFIG_SMP
2420 extern void do_set_cpus_allowed(struct task_struct *p,
2421                                const struct cpumask *new_mask);
2422 
2423 extern int set_cpus_allowed_ptr(struct task_struct *p,
2424                                 const struct cpumask *new_mask);
2425 #else
2426 static inline void do_set_cpus_allowed(struct task_struct *p,
2427                                       const struct cpumask *new_mask)
2428 {
2429 }
2430 static inline int set_cpus_allowed_ptr(struct task_struct *p,
2431                                        const struct cpumask *new_mask)
2432 {
2433         if (!cpumask_test_cpu(0, new_mask))
2434                 return -EINVAL;
2435         return 0;
2436 }
2437 #endif
2438 
2439 #ifdef CONFIG_NO_HZ_COMMON
2440 void calc_load_enter_idle(void);
2441 void calc_load_exit_idle(void);
2442 #else
2443 static inline void calc_load_enter_idle(void) { }
2444 static inline void calc_load_exit_idle(void) { }
2445 #endif /* CONFIG_NO_HZ_COMMON */
2446 
2447 /*
2448  * Do not use outside of architecture code which knows its limitations.
2449  *
2450  * sched_clock() has no promise of monotonicity or bounded drift between
2451  * CPUs, use (which you should not) requires disabling IRQs.
2452  *
2453  * Please use one of the three interfaces below.
2454  */
2455 extern unsigned long long notrace sched_clock(void);
2456 /*
2457  * See the comment in kernel/sched/clock.c
2458  */
2459 extern u64 running_clock(void);
2460 extern u64 sched_clock_cpu(int cpu);
2461 
2462 
2463 extern void sched_clock_init(void);
2464 
2465 #ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
2466 static inline void sched_clock_tick(void)
2467 {
2468 }
2469 
2470 static inline void sched_clock_idle_sleep_event(void)
2471 {
2472 }
2473 
2474 static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
2475 {
2476 }
2477 
2478 static inline u64 cpu_clock(int cpu)
2479 {
2480         return sched_clock();
2481 }
2482 
2483 static inline u64 local_clock(void)
2484 {
2485         return sched_clock();
2486 }
2487 #else
2488 /*
2489  * Architectures can set this to 1 if they have specified
2490  * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
2491  * but then during bootup it turns out that sched_clock()
2492  * is reliable after all:
2493  */
2494 extern int sched_clock_stable(void);
2495 extern void set_sched_clock_stable(void);
2496 extern void clear_sched_clock_stable(void);
2497 
2498 extern void sched_clock_tick(void);
2499 extern void sched_clock_idle_sleep_event(void);
2500 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2501 
2502 /*
2503  * As outlined in clock.c, provides a fast, high resolution, nanosecond
2504  * time source that is monotonic per cpu argument and has bounded drift
2505  * between cpus.
2506  *
2507  * ######################### BIG FAT WARNING ##########################
2508  * # when comparing cpu_clock(i) to cpu_clock(j) for i != j, time can #
2509  * # go backwards !!                                                  #
2510  * ####################################################################
2511  */
2512 static inline u64 cpu_clock(int cpu)
2513 {
2514         return sched_clock_cpu(cpu);
2515 }
2516 
2517 static inline u64 local_clock(void)
2518 {
2519         return sched_clock_cpu(raw_smp_processor_id());
2520 }
2521 #endif
2522 
2523 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
2524 /*
2525  * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
2526  * The reason for this explicit opt-in is not to have perf penalty with
2527  * slow sched_clocks.
2528  */
2529 extern void enable_sched_clock_irqtime(void);
2530 extern void disable_sched_clock_irqtime(void);
2531 #else
2532 static inline void enable_sched_clock_irqtime(void) {}
2533 static inline void disable_sched_clock_irqtime(void) {}
2534 #endif
2535 
2536 extern unsigned long long
2537 task_sched_runtime(struct task_struct *task);
2538 
2539 /* sched_exec is called by processes performing an exec */
2540 #ifdef CONFIG_SMP
2541 extern void sched_exec(void);
2542 #else
2543 #define sched_exec()   {}
2544 #endif
2545 
2546 extern void sched_clock_idle_sleep_event(void);
2547 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2548 
2549 #ifdef CONFIG_HOTPLUG_CPU
2550 extern void idle_task_exit(void);
2551 #else
2552 static inline void idle_task_exit(void) {}
2553 #endif
2554 
2555 #if defined(CONFIG_NO_HZ_COMMON) && defined(CONFIG_SMP)
2556 extern void wake_up_nohz_cpu(int cpu);
2557 #else
2558 static inline void wake_up_nohz_cpu(int cpu) { }
2559 #endif
2560 
2561 #ifdef CONFIG_NO_HZ_FULL
2562 extern u64 scheduler_tick_max_deferment(void);
2563 #endif
2564 
2565 #ifdef CONFIG_SCHED_AUTOGROUP
2566 extern void sched_autogroup_create_attach(struct task_struct *p);
2567 extern void sched_autogroup_detach(struct task_struct *p);
2568 extern void sched_autogroup_fork(struct signal_struct *sig);
2569 extern void sched_autogroup_exit(struct signal_struct *sig);
2570 extern void sched_autogroup_exit_task(struct task_struct *p);
2571 #ifdef CONFIG_PROC_FS
2572 extern void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m);
2573 extern int proc_sched_autogroup_set_nice(struct task_struct *p, int nice);
2574 #endif
2575 #else
2576 static inline void sched_autogroup_create_attach(struct task_struct *p) { }
2577 static inline void sched_autogroup_detach(struct task_struct *p) { }
2578 static inline void sched_autogroup_fork(struct signal_struct *sig) { }
2579 static inline void sched_autogroup_exit(struct signal_struct *sig) { }
2580 static inline void sched_autogroup_exit_task(struct task_struct *p) { }
2581 #endif
2582 
2583 extern int yield_to(struct task_struct *p, bool preempt);
2584 extern void set_user_nice(struct task_struct *p, long nice);
2585 extern int task_prio(const struct task_struct *p);
2586 /**
2587  * task_nice - return the nice value of a given task.
2588  * @p: the task in question.
2589  *
2590  * Return: The nice value [ -20 ... 0 ... 19 ].
2591  */
2592 static inline int task_nice(const struct task_struct *p)
2593 {
2594         return PRIO_TO_NICE((p)->static_prio);
2595 }
2596 extern int can_nice(const struct task_struct *p, const int nice);
2597 extern int task_curr(const struct task_struct *p);
2598 extern int idle_cpu(int cpu);
2599 extern int sched_setscheduler(struct task_struct *, int,
2600                               const struct sched_param *);
2601 extern int sched_setscheduler_nocheck(struct task_struct *, int,
2602                                       const struct sched_param *);
2603 extern int sched_setattr(struct task_struct *,
2604                          const struct sched_attr *);
2605 extern struct task_struct *idle_task(int cpu);
2606 /**
2607  * is_idle_task - is the specified task an idle task?
2608  * @p: the task in question.
2609  *
2610  * Return: 1 if @p is an idle task. 0 otherwise.
2611  */
2612 static inline bool is_idle_task(const struct task_struct *p)
2613 {
2614         return p->pid == 0;
2615 }
2616 extern struct task_struct *curr_task(int cpu);
2617 extern void ia64_set_curr_task(int cpu, struct task_struct *p);
2618 
2619 void yield(void);
2620 
2621 union thread_union {
2622 #ifndef CONFIG_THREAD_INFO_IN_TASK
2623         struct thread_info thread_info;
2624 #endif
2625         unsigned long stack[THREAD_SIZE/sizeof(long)];
2626 };
2627 
2628 #ifndef __HAVE_ARCH_KSTACK_END
2629 static inline int kstack_end(void *addr)
2630 {
2631         /* Reliable end of stack detection:
2632          * Some APM bios versions misalign the stack
2633          */
2634         return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
2635 }
2636 #endif
2637 
2638 extern union thread_union init_thread_union;
2639 extern struct task_struct init_task;
2640 
2641 extern struct   mm_struct init_mm;
2642 
2643 extern struct pid_namespace init_pid_ns;
2644 
2645 /*
2646  * find a task by one of its numerical ids
2647  *
2648  * find_task_by_pid_ns():
2649  *      finds a task by its pid in the specified namespace
2650  * find_task_by_vpid():
2651  *      finds a task by its virtual pid
2652  *
2653  * see also find_vpid() etc in include/linux/pid.h
2654  */
2655 
2656 extern struct task_struct *find_task_by_vpid(pid_t nr);
2657 extern struct task_struct *find_task_by_pid_ns(pid_t nr,
2658                 struct pid_namespace *ns);
2659 
2660 /* per-UID process charging. */
2661 extern struct user_struct * alloc_uid(kuid_t);
2662 static inline struct user_struct *get_uid(struct user_struct *u)
2663 {
2664         atomic_inc(&u->__count);
2665         return u;
2666 }
2667 extern void free_uid(struct user_struct *);
2668 
2669 #include <asm/current.h>
2670 
2671 extern void xtime_update(unsigned long ticks);
2672 
2673 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2674 extern int wake_up_process(struct task_struct *tsk);
2675 extern void wake_up_new_task(struct task_struct *tsk);
2676 #ifdef CONFIG_SMP
2677  extern void kick_process(struct task_struct *tsk);
2678 #else
2679  static inline void kick_process(struct task_struct *tsk) { }
2680 #endif
2681 extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
2682 extern void sched_dead(struct task_struct *p);
2683 
2684 extern void proc_caches_init(void);
2685 extern void flush_signals(struct task_struct *);
2686 extern void ignore_signals(struct task_struct *);
2687 extern void flush_signal_handlers(struct task_struct *, int force_default);
2688 extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
2689 
2690 static inline int kernel_dequeue_signal(siginfo_t *info)
2691 {
2692         struct task_struct *tsk = current;
2693         siginfo_t __info;
2694         int ret;
2695 
2696         spin_lock_irq(&tsk->sighand->siglock);
2697         ret = dequeue_signal(tsk, &tsk->blocked, info ?: &__info);
2698         spin_unlock_irq(&tsk->sighand->siglock);
2699 
2700         return ret;
2701 }
2702 
2703 static inline void kernel_signal_stop(void)
2704 {
2705         spin_lock_irq(&current->sighand->siglock);
2706         if (current->jobctl & JOBCTL_STOP_DEQUEUED)
2707                 __set_current_state(TASK_STOPPED);
2708         spin_unlock_irq(&current->sighand->siglock);
2709 
2710         schedule();
2711 }
2712 
2713 extern void release_task(struct task_struct * p);
2714 extern int send_sig_info(int, struct siginfo *, struct task_struct *);
2715 extern int force_sigsegv(int, struct task_struct *);
2716 extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2717 extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
2718 extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2719 extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *,
2720                                 const struct cred *, u32);
2721 extern int kill_pgrp(struct pid *pid, int sig, int priv);
2722 extern int kill_pid(struct pid *pid, int sig, int priv);
2723 extern int kill_proc_info(int, struct siginfo *, pid_t);
2724 extern __must_check bool do_notify_parent(struct task_struct *, int);
2725 extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
2726 extern void force_sig(int, struct task_struct *);
2727 extern int send_sig(int, struct task_struct *, int);
2728 extern int zap_other_threads(struct task_struct *p);
2729 extern struct sigqueue *sigqueue_alloc(void);
2730 extern void sigqueue_free(struct sigqueue *);
2731 extern int send_sigqueue(struct sigqueue *,  struct task_struct *, int group);
2732 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
2733 
2734 #ifdef TIF_RESTORE_SIGMASK
2735 /*
2736  * Legacy restore_sigmask accessors.  These are inefficient on
2737  * SMP architectures because they require atomic operations.
2738  */
2739 
2740 /**
2741  * set_restore_sigmask() - make sure saved_sigmask processing gets done
2742  *
2743  * This sets TIF_RESTORE_SIGMASK and ensures that the arch signal code
2744  * will run before returning to user mode, to process the flag.  For
2745  * all callers, TIF_SIGPENDING is already set or it's no harm to set
2746  * it.  TIF_RESTORE_SIGMASK need not be in the set of bits that the
2747  * arch code will notice on return to user mode, in case those bits
2748  * are scarce.  We set TIF_SIGPENDING here to ensure that the arch
2749  * signal code always gets run when TIF_RESTORE_SIGMASK is set.
2750  */
2751 static inline void set_restore_sigmask(void)
2752 {
2753         set_thread_flag(TIF_RESTORE_SIGMASK);
2754         WARN_ON(!test_thread_flag(TIF_SIGPENDING));
2755 }
2756 static inline void clear_restore_sigmask(void)
2757 {
2758         clear_thread_flag(TIF_RESTORE_SIGMASK);
2759 }
2760 static inline bool test_restore_sigmask(void)
2761 {
2762         return test_thread_flag(TIF_RESTORE_SIGMASK);
2763 }
2764 static inline bool test_and_clear_restore_sigmask(void)
2765 {
2766         return test_and_clear_thread_flag(TIF_RESTORE_SIGMASK);
2767 }
2768 
2769 #else   /* TIF_RESTORE_SIGMASK */
2770 
2771 /* Higher-quality implementation, used if TIF_RESTORE_SIGMASK doesn't exist. */
2772 static inline void set_restore_sigmask(void)
2773 {
2774         current->restore_sigmask = true;
2775         WARN_ON(!test_thread_flag(TIF_SIGPENDING));
2776 }
2777 static inline void clear_restore_sigmask(void)
2778 {
2779         current->restore_sigmask = false;
2780 }
2781 static inline bool test_restore_sigmask(void)
2782 {
2783         return current->restore_sigmask;
2784 }
2785 static inline bool test_and_clear_restore_sigmask(void)
2786 {
2787         if (!current->restore_sigmask)
2788                 return false;
2789         current->restore_sigmask = false;
2790         return true;
2791 }
2792 #endif
2793 
2794 static inline void restore_saved_sigmask(void)
2795 {
2796         if (test_and_clear_restore_sigmask())
2797                 __set_current_blocked(&current->saved_sigmask);
2798 }
2799 
2800 static inline sigset_t *sigmask_to_save(void)
2801 {
2802         sigset_t *res = &current->blocked;
2803         if (unlikely(test_restore_sigmask()))
2804                 res = &current->saved_sigmask;
2805         return res;
2806 }
2807 
2808 static inline int kill_cad_pid(int sig, int priv)
2809 {
2810         return kill_pid(cad_pid, sig, priv);
2811 }
2812 
2813 /* These can be the second arg to send_sig_info/send_group_sig_info.  */
2814 #define SEND_SIG_NOINFO ((struct siginfo *) 0)
2815 #define SEND_SIG_PRIV   ((struct siginfo *) 1)
2816 #define SEND_SIG_FORCED ((struct siginfo *) 2)
2817 
2818 /*
2819  * True if we are on the alternate signal stack.
2820  */
2821 static inline int on_sig_stack(unsigned long sp)
2822 {
2823         /*
2824          * If the signal stack is SS_AUTODISARM then, by construction, we
2825          * can't be on the signal stack unless user code deliberately set
2826          * SS_AUTODISARM when we were already on it.
2827          *
2828          * This improves reliability: if user state gets corrupted such that
2829          * the stack pointer points very close to the end of the signal stack,
2830          * then this check will enable the signal to be handled anyway.
2831          */
2832         if (current->sas_ss_flags & SS_AUTODISARM)
2833                 return 0;
2834 
2835 #ifdef CONFIG_STACK_GROWSUP
2836         return sp >= current->sas_ss_sp &&
2837                 sp - current->sas_ss_sp < current->sas_ss_size;
2838 #else
2839         return sp > current->sas_ss_sp &&
2840                 sp - current->sas_ss_sp <= current->sas_ss_size;
2841 #endif
2842 }
2843 
2844 static inline int sas_ss_flags(unsigned long sp)
2845 {
2846         if (!current->sas_ss_size)
2847                 return SS_DISABLE;
2848 
2849         return on_sig_stack(sp) ? SS_ONSTACK : 0;
2850 }
2851 
2852 static inline void sas_ss_reset(struct task_struct *p)
2853 {
2854         p->sas_ss_sp = 0;
2855         p->sas_ss_size = 0;
2856         p->sas_ss_flags = SS_DISABLE;
2857 }
2858 
2859 static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig)
2860 {
2861         if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))
2862 #ifdef CONFIG_STACK_GROWSUP
2863                 return current->sas_ss_sp;
2864 #else
2865                 return current->sas_ss_sp + current->sas_ss_size;
2866 #endif
2867         return sp;
2868 }
2869 
2870 /*
2871  * Routines for handling mm_structs
2872  */
2873 extern struct mm_struct * mm_alloc(void);
2874 
2875 /* mmdrop drops the mm and the page tables */
2876 extern void __mmdrop(struct mm_struct *);
2877 static inline void mmdrop(struct mm_struct *mm)
2878 {
2879         if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2880                 __mmdrop(mm);
2881 }
2882 
2883 static inline void mmdrop_async_fn(struct work_struct *work)
2884 {
2885         struct mm_struct *mm = container_of(work, struct mm_struct, async_put_work);
2886         __mmdrop(mm);
2887 }
2888 
2889 static inline void mmdrop_async(struct mm_struct *mm)
2890 {
2891         if (unlikely(atomic_dec_and_test(&mm->mm_count))) {
2892                 INIT_WORK(&mm->async_put_work, mmdrop_async_fn);
2893                 schedule_work(&mm->async_put_work);
2894         }
2895 }
2896 
2897 static inline bool mmget_not_zero(struct mm_struct *mm)
2898 {
2899         return atomic_inc_not_zero(&mm->mm_users);
2900 }
2901 
2902 /* mmput gets rid of the mappings and all user-space */
2903 extern void mmput(struct mm_struct *);
2904 #ifdef CONFIG_MMU
2905 /* same as above but performs the slow path from the async context. Can
2906  * be called from the atomic context as well
2907  */
2908 extern void mmput_async(struct mm_struct *);
2909 #endif
2910 
2911 /* Grab a reference to a task's mm, if it is not already going away */
2912 extern struct mm_struct *get_task_mm(struct task_struct *task);
2913 /*
2914  * Grab a reference to a task's mm, if it is not already going away
2915  * and ptrace_may_access with the mode parameter passed to it
2916  * succeeds.
2917  */
2918 extern struct mm_struct *mm_access(struct task_struct *task, unsigned int mode);
2919 /* Remove the current tasks stale references to the old mm_struct */
2920 extern void mm_release(struct task_struct *, struct mm_struct *);
2921 
2922 #ifdef CONFIG_HAVE_COPY_THREAD_TLS
2923 extern int copy_thread_tls(unsigned long, unsigned long, unsigned long,
2924                         struct task_struct *, unsigned long);
2925 #else
2926 extern int copy_thread(unsigned long, unsigned long, unsigned long,
2927                         struct task_struct *);
2928 
2929 /* Architectures that haven't opted into copy_thread_tls get the tls argument
2930  * via pt_regs, so ignore the tls argument passed via C. */
2931 static inline int copy_thread_tls(
2932                 unsigned long clone_flags, unsigned long sp, unsigned long arg,
2933                 struct task_struct *p, unsigned long tls)
2934 {
2935         return copy_thread(clone_flags, sp, arg, p);
2936 }
2937 #endif
2938 extern void flush_thread(void);
2939 
2940 #ifdef CONFIG_HAVE_EXIT_THREAD
2941 extern void exit_thread(struct task_struct *tsk);
2942 #else
2943 static inline void exit_thread(struct task_struct *tsk)
2944 {
2945 }
2946 #endif
2947 
2948 extern void exit_files(struct task_struct *);
2949 extern void __cleanup_sighand(struct sighand_struct *);
2950 
2951 extern void exit_itimers(struct signal_struct *);
2952 extern void flush_itimer_signals(void);
2953 
2954 extern void do_group_exit(int);
2955 
2956 extern int do_execve(struct filename *,
2957                      const char __user * const __user *,
2958                      const char __user * const __user *);
2959 extern int do_execveat(int, struct filename *,
2960                        const char __user * const __user *,
2961                        const char __user * const __user *,
2962                        int);
2963 extern long _do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *, unsigned long);
2964 extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
2965 struct task_struct *fork_idle(int);
2966 extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
2967 
2968 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
2969 static inline void set_task_comm(struct task_struct *tsk, const char *from)
2970 {
2971         __set_task_comm(tsk, from, false);
2972 }
2973 extern char *get_task_comm(char *to, struct task_struct *tsk);
2974 
2975 #ifdef CONFIG_SMP
2976 void scheduler_ipi(void);
2977 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
2978 #else
2979 static inline void scheduler_ipi(void) { }
2980 static inline unsigned long wait_task_inactive(struct task_struct *p,
2981                                                long match_state)
2982 {
2983         return 1;
2984 }
2985 #endif
2986 
2987 #define tasklist_empty() \
2988         list_empty(&init_task.tasks)
2989 
2990 #define next_task(p) \
2991         list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
2992 
2993 #define for_each_process(p) \
2994         for (p = &init_task ; (p = next_task(p)) != &init_task ; )
2995 
2996 extern bool current_is_single_threaded(void);
2997 
2998 /*
2999  * Careful: do_each_thread/while_each_thread is a double loop so
3000  *          'break' will not work as expected - use goto instead.
3001  */
3002 #define do_each_thread(g, t) \
3003         for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
3004 
3005 #define while_each_thread(g, t) \
3006         while ((t = next_thread(t)) != g)
3007 
3008 #define __for_each_thread(signal, t)    \
3009         list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node)
3010 
3011 #define for_each_thread(p, t)           \
3012         __for_each_thread((p)->signal, t)
3013 
3014 /* Careful: this is a double loop, 'break' won't work as expected. */
3015 #define for_each_process_thread(p, t)   \
3016         for_each_process(p) for_each_thread(p, t)
3017 
3018 static inline int get_nr_threads(struct task_struct *tsk)
3019 {
3020         return tsk->signal->nr_threads;
3021 }
3022 
3023 static inline bool thread_group_leader(struct task_struct *p)
3024 {
3025         return p->exit_signal >= 0;
3026 }
3027 
3028 /* Do to the insanities of de_thread it is possible for a process
3029  * to have the pid of the thread group leader without actually being
3030  * the thread group leader.  For iteration through the pids in proc
3031  * all we care about is that we have a task with the appropriate
3032  * pid, we don't actually care if we have the right task.
3033  */
3034 static inline bool has_group_leader_pid(struct task_struct *p)
3035 {
3036         return task_pid(p) == p->signal->leader_pid;
3037 }
3038 
3039 static inline
3040 bool same_thread_group(struct task_struct *p1, struct task_struct *p2)
3041 {
3042         return p1->signal == p2->signal;
3043 }
3044 
3045 static inline struct task_struct *next_thread(const struct task_struct *p)
3046 {
3047         return list_entry_rcu(p->thread_group.next,
3048                               struct task_struct, thread_group);
3049 }
3050 
3051 static inline int thread_group_empty(struct task_struct *p)
3052 {
3053         return list_empty(&p->thread_group);
3054 }
3055 
3056 #define delay_group_leader(p) \
3057                 (thread_group_leader(p) && !thread_group_empty(p))
3058 
3059 /*
3060  * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
3061  * subscriptions and synchronises with wait4().  Also used in procfs.  Also
3062  * pins the final release of task.io_context.  Also protects ->cpuset and
3063  * ->cgroup.subsys[]. And ->vfork_done.
3064  *
3065  * Nests both inside and outside of read_lock(&tasklist_lock).
3066  * It must not be nested with write_lock_irq(&tasklist_lock),
3067  * neither inside nor outside.
3068  */
3069 static inline void task_lock(struct task_struct *p)
3070 {
3071         spin_lock(&p->alloc_lock);
3072 }
3073 
3074 static inline void task_unlock(struct task_struct *p)
3075 {
3076         spin_unlock(&p->alloc_lock);
3077 }
3078 
3079 extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
3080                                                         unsigned long *flags);
3081 
3082 static inline struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
3083                                                        unsigned long *flags)
3084 {
3085         struct sighand_struct *ret;
3086 
3087         ret = __lock_task_sighand(tsk, flags);
3088         (void)__cond_lock(&tsk->sighand->siglock, ret);
3089         return ret;
3090 }
3091 
3092 static inline void unlock_task_sighand(struct task_struct *tsk,
3093                                                 unsigned long *flags)
3094 {
3095         spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
3096 }
3097 
3098 /**
3099  * threadgroup_change_begin - mark the beginning of changes to a threadgroup
3100  * @tsk: task causing the changes
3101  *
3102  * All operations which modify a threadgroup - a new thread joining the
3103  * group, death of a member thread (the assertion of PF_EXITING) and
3104  * exec(2) dethreading the process and replacing the leader - are wrapped
3105  * by threadgroup_change_{begin|end}().  This is to provide a place which
3106  * subsystems needing threadgroup stability can hook into for
3107  * synchronization.
3108  */
3109 static inline void threadgroup_change_begin(struct task_struct *tsk)
3110 {
3111         might_sleep();
3112         cgroup_threadgroup_change_begin(tsk);
3113 }
3114 
3115 /**
3116  * threadgroup_change_end - mark the end of changes to a threadgroup
3117  * @tsk: task causing the changes
3118  *
3119  * See threadgroup_change_begin().
3120  */
3121 static inline void threadgroup_change_end(struct task_struct *tsk)
3122 {
3123         cgroup_threadgroup_change_end(tsk);
3124 }
3125 
3126 #ifdef CONFIG_THREAD_INFO_IN_TASK
3127 
3128 static inline struct thread_info *task_thread_info(struct task_struct *task)
3129 {
3130         return &task->thread_info;
3131 }
3132 
3133 /*
3134  * When accessing the stack of a non-current task that might exit, use
3135  * try_get_task_stack() instead.  task_stack_page will return a pointer
3136  * that could get freed out from under you.
3137  */
3138 static inline void *task_stack_page(const struct task_struct *task)
3139 {
3140         return task->stack;
3141 }
3142 
3143 #define setup_thread_stack(new,old)     do { } while(0)
3144 
3145 static inline unsigned long *end_of_stack(const struct task_struct *task)
3146 {
3147         return task->stack;
3148 }
3149 
3150 #elif !defined(__HAVE_THREAD_FUNCTIONS)
3151 
3152 #define task_thread_info(task)  ((struct thread_info *)(task)->stack)
3153 #define task_stack_page(task)   ((void *)(task)->stack)
3154 
3155 static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
3156 {
3157         *task_thread_info(p) = *task_thread_info(org);
3158         task_thread_info(p)->task = p;
3159 }
3160 
3161 /*
3162  * Return the address of the last usable long on the stack.
3163  *
3164  * When the stack grows down, this is just above the thread
3165  * info struct. Going any lower will corrupt the threadinfo.
3166  *
3167  * When the stack grows up, this is the highest address.
3168  * Beyond that position, we corrupt data on the next page.
3169  */
3170 static inline unsigned long *end_of_stack(struct task_struct *p)
3171 {
3172 #ifdef CONFIG_STACK_GROWSUP
3173         return (unsigned long *)((unsigned long)task_thread_info(p) + THREAD_SIZE) - 1;
3174 #else
3175         return (unsigned long *)(task_thread_info(p) + 1);
3176 #endif
3177 }
3178 
3179 #endif
3180 
3181 #ifdef CONFIG_THREAD_INFO_IN_TASK
3182 static inline void *try_get_task_stack(struct task_struct *tsk)
3183 {
3184         return atomic_inc_not_zero(&tsk->stack_refcount) ?
3185                 task_stack_page(tsk) : NULL;
3186 }
3187 
3188 extern void put_task_stack(struct task_struct *tsk);
3189 #else
3190 static inline void *try_get_task_stack(struct task_struct *tsk)
3191 {
3192         return task_stack_page(tsk);
3193 }
3194 
3195 static inline void put_task_stack(struct task_struct *tsk) {}
3196 #endif
3197 
3198 #define task_stack_end_corrupted(task) \
3199                 (*(end_of_stack(task)) != STACK_END_MAGIC)
3200 
3201 static inline int object_is_on_stack(void *obj)
3202 {
3203         void *stack = task_stack_page(current);
3204 
3205         return (obj >= stack) && (obj < (stack + THREAD_SIZE));
3206 }
3207 
3208 extern void thread_stack_cache_init(void);
3209 
3210 #ifdef CONFIG_DEBUG_STACK_USAGE
3211 static inline unsigned long stack_not_used(struct task_struct *p)
3212 {
3213         unsigned long *n = end_of_stack(p);
3214 
3215         do {    /* Skip over canary */
3216 # ifdef CONFIG_STACK_GROWSUP
3217                 n--;
3218 # else
3219                 n++;
3220 # endif
3221         } while (!*n);
3222 
3223 # ifdef CONFIG_STACK_GROWSUP
3224         return (unsigned long)end_of_stack(p) - (unsigned long)n;
3225 # else
3226         return (unsigned long)n - (unsigned long)end_of_stack(p);
3227 # endif
3228 }
3229 #endif
3230 extern void set_task_stack_end_magic(struct task_struct *tsk);
3231 
3232 /* set thread flags in other task's structures
3233  * - see asm/thread_info.h for TIF_xxxx flags available
3234  */
3235 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
3236 {
3237         set_ti_thread_flag(task_thread_info(tsk), flag);
3238 }
3239 
3240 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
3241 {
3242         clear_ti_thread_flag(task_thread_info(tsk), flag);
3243 }
3244 
3245 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
3246 {
3247         return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
3248 }
3249 
3250 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
3251 {
3252         return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
3253 }
3254 
3255 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
3256 {
3257         return test_ti_thread_flag(task_thread_info(tsk), flag);
3258 }
3259 
3260 static inline void set_tsk_need_resched(struct task_struct *tsk)
3261 {
3262         set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
3263 }
3264 
3265 static inline void clear_tsk_need_resched(struct task_struct *tsk)
3266 {
3267         clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
3268 }
3269 
3270 static inline int test_tsk_need_resched(struct task_struct *tsk)
3271 {
3272         return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
3273 }
3274 
3275 static inline int restart_syscall(void)
3276 {
3277         set_tsk_thread_flag(current, TIF_SIGPENDING);
3278         return -ERESTARTNOINTR;
3279 }
3280 
3281 static inline int signal_pending(struct task_struct *p)
3282 {
3283         return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
3284 }
3285 
3286 static inline int __fatal_signal_pending(struct task_struct *p)
3287 {
3288         return unlikely(sigismember(&p->pending.signal, SIGKILL));
3289 }
3290 
3291 static inline int fatal_signal_pending(struct task_struct *p)
3292 {
3293         return signal_pending(p) && __fatal_signal_pending(p);
3294 }
3295 
3296 static inline int signal_pending_state(long state, struct task_struct *p)
3297 {
3298         if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
3299                 return 0;
3300         if (!signal_pending(p))
3301                 return 0;
3302 
3303         return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
3304 }
3305 
3306 /*
3307  * cond_resched() and cond_resched_lock(): latency reduction via
3308  * explicit rescheduling in places that are safe. The return
3309  * value indicates whether a reschedule was done in fact.
3310  * cond_resched_lock() will drop the spinlock before scheduling,
3311  * cond_resched_softirq() will enable bhs before scheduling.
3312  */
3313 #ifndef CONFIG_PREEMPT
3314 extern int _cond_resched(void);
3315 #else
3316 static inline int _cond_resched(void) { return 0; }
3317 #endif
3318 
3319 #define cond_resched() ({                       \
3320         ___might_sleep(__FILE__, __LINE__, 0);  \
3321         _cond_resched();                        \
3322 })
3323 
3324 extern int __cond_resched_lock(spinlock_t *lock);
3325 
3326 #define cond_resched_lock(lock) ({                              \
3327         ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
3328         __cond_resched_lock(lock);                              \
3329 })
3330 
3331 extern int __cond_resched_softirq(void);
3332 
3333 #define cond_resched_softirq() ({                                       \
3334         ___might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET);     \
3335         __cond_resched_softirq();                                       \
3336 })
3337 
3338 static inline void cond_resched_rcu(void)
3339 {
3340 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
3341         rcu_read_unlock();
3342         cond_resched();
3343         rcu_read_lock();
3344 #endif
3345 }
3346 
3347 static inline unsigned long get_preempt_disable_ip(struct task_struct *p)
3348 {
3349 #ifdef CONFIG_DEBUG_PREEMPT
3350         return p->preempt_disable_ip;
3351 #else
3352         return 0;
3353 #endif
3354 }
3355 
3356 /*
3357  * Does a critical section need to be broken due to another
3358  * task waiting?: (technically does not depend on CONFIG_PREEMPT,
3359  * but a general need for low latency)
3360  */
3361 static inline int spin_needbreak(spinlock_t *lock)
3362 {
3363 #ifdef CONFIG_PREEMPT
3364         return spin_is_contended(lock);
3365 #else
3366         return 0;
3367 #endif
3368 }
3369 
3370 /*
3371  * Idle thread specific functions to determine the need_resched
3372  * polling state.
3373  */
3374 #ifdef TIF_POLLING_NRFLAG
3375 static inline int tsk_is_polling(struct task_struct *p)
3376 {
3377         return test_tsk_thread_flag(p, TIF_POLLING_NRFLAG);
3378 }
3379 
3380 static inline void __current_set_polling(void)
3381 {
3382         set_thread_flag(TIF_POLLING_NRFLAG);
3383 }
3384 
3385 static inline bool __must_check current_set_polling_and_test(void)
3386 {
3387         __current_set_polling();
3388 
3389         /*
3390          * Polling state must be visible before we test NEED_RESCHED,
3391          * paired by resched_curr()
3392          */
3393         smp_mb__after_atomic();
3394 
3395         return unlikely(tif_need_resched());
3396 }
3397 
3398 static inline void __current_clr_polling(void)
3399 {
3400         clear_thread_flag(TIF_POLLING_NRFLAG);
3401 }
3402 
3403 static inline bool __must_check current_clr_polling_and_test(void)
3404 {
3405         __current_clr_polling();
3406 
3407         /*
3408          * Polling state must be visible before we test NEED_RESCHED,
3409          * paired by resched_curr()
3410          */
3411         smp_mb__after_atomic();
3412 
3413         return unlikely(tif_need_resched());
3414 }
3415 
3416 #else
3417 static inline int tsk_is_polling(struct task_struct *p) { return 0; }
3418 static inline void __current_set_polling(void) { }
3419 static inline void __current_clr_polling(void) { }
3420 
3421 static inline bool __must_check current_set_polling_and_test(void)
3422 {
3423         return unlikely(tif_need_resched());
3424 }
3425 static inline bool __must_check current_clr_polling_and_test(void)
3426 {
3427         return unlikely(tif_need_resched());
3428 }
3429 #endif
3430 
3431 static inline void current_clr_polling(void)
3432 {
3433         __current_clr_polling();
3434 
3435         /*
3436          * Ensure we check TIF_NEED_RESCHED after we clear the polling bit.
3437          * Once the bit is cleared, we'll get IPIs with every new
3438          * TIF_NEED_RESCHED and the IPI handler, scheduler_ipi(), will also
3439          * fold.
3440          */
3441         smp_mb(); /* paired with resched_curr() */
3442 
3443         preempt_fold_need_resched();
3444 }
3445 
3446 static __always_inline bool need_resched(void)
3447 {
3448         return unlikely(tif_need_resched());
3449 }
3450 
3451 /*
3452  * Thread group CPU time accounting.
3453  */
3454 void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
3455 void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
3456 
3457 /*
3458  * Reevaluate whether the task has signals pending delivery.
3459  * Wake the task if so.
3460  * This is required every time the blocked sigset_t changes.
3461  * callers must hold sighand->siglock.
3462  */
3463 extern void recalc_sigpending_and_wake(struct task_struct *t);
3464 extern void recalc_sigpending(void);
3465 
3466 extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
3467 
3468 static inline void signal_wake_up(struct task_struct *t, bool resume)
3469 {
3470         signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0);
3471 }
3472 static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
3473 {
3474         signal_wake_up_state(t, resume ? __TASK_TRACED : 0);
3475 }
3476 
3477 /*
3478  * Wrappers for p->thread_info->cpu access. No-op on UP.
3479  */
3480 #ifdef CONFIG_SMP
3481 
3482 static inline unsigned int task_cpu(const struct task_struct *p)
3483 {
3484 #ifdef CONFIG_THREAD_INFO_IN_TASK
3485         return p->cpu;
3486 #else
3487         return task_thread_info(p)->cpu;
3488 #endif
3489 }
3490 
3491 static inline int task_node(const struct task_struct *p)
3492 {
3493         return cpu_to_node(task_cpu(p));
3494 }
3495 
3496 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
3497 
3498 #else
3499 
3500 static inline unsigned int task_cpu(const struct task_struct *p)
3501 {
3502         return 0;
3503 }
3504 
3505 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
3506 {
3507 }
3508 
3509 #endif /* CONFIG_SMP */
3510 
3511 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
3512 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
3513 
3514 #ifdef CONFIG_CGROUP_SCHED
3515 extern struct task_group root_task_group;
3516 #endif /* CONFIG_CGROUP_SCHED */
3517 
3518 extern int task_can_switch_user(struct user_struct *up,
3519                                         struct task_struct *tsk);
3520 
3521 #ifdef CONFIG_TASK_XACCT
3522 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
3523 {
3524         tsk->ioac.rchar += amt;
3525 }
3526 
3527 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
3528 {
3529         tsk->ioac.wchar += amt;
3530 }
3531 
3532 static inline void inc_syscr(struct task_struct *tsk)
3533 {
3534         tsk->ioac.syscr++;
3535 }
3536 
3537 static inline void inc_syscw(struct task_struct *tsk)
3538 {
3539         tsk->ioac.syscw++;
3540 }
3541 #else
3542 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
3543 {
3544 }
3545 
3546 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
3547 {
3548 }
3549 
3550 static inline void inc_syscr(struct task_struct *tsk)
3551 {
3552 }
3553 
3554 static inline void inc_syscw(struct task_struct *tsk)
3555 {
3556 }
3557 #endif
3558 
3559 #ifndef TASK_SIZE_OF
3560 #define TASK_SIZE_OF(tsk)       TASK_SIZE
3561 #endif
3562 
3563 #ifdef CONFIG_MEMCG
3564 extern void mm_update_next_owner(struct mm_struct *mm);
3565 #else
3566 static inline void mm_update_next_owner(struct mm_struct *mm)
3567 {
3568 }
3569 #endif /* CONFIG_MEMCG */
3570 
3571 static inline unsigned long task_rlimit(const struct task_struct *tsk,
3572                 unsigned int limit)
3573 {
3574         return READ_ONCE(tsk->signal->rlim[limit].rlim_cur);
3575 }
3576 
3577 static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
3578                 unsigned int limit)
3579 {
3580         return READ_ONCE(tsk->signal->rlim[limit].rlim_max);
3581 }
3582 
3583 static inline unsigned long rlimit(unsigned int limit)
3584 {
3585         return task_rlimit(current, limit);
3586 }
3587 
3588 static inline unsigned long rlimit_max(unsigned int limit)
3589 {
3590         return task_rlimit_max(current, limit);
3591 }
3592 
3593 #define SCHED_CPUFREQ_RT        (1U << 0)
3594 #define SCHED_CPUFREQ_DL        (1U << 1)
3595 #define SCHED_CPUFREQ_IOWAIT    (1U << 2)
3596 
3597 #define SCHED_CPUFREQ_RT_DL     (SCHED_CPUFREQ_RT | SCHED_CPUFREQ_DL)
3598 
3599 #ifdef CONFIG_CPU_FREQ
3600 struct update_util_data {
3601        void (*func)(struct update_util_data *data, u64 time, unsigned int flags);
3602 };
3603 
3604 void cpufreq_add_update_util_hook(int cpu, struct update_util_data *data,
3605                        void (*func)(struct update_util_data *data, u64 time,
3606                                     unsigned int flags));
3607 void cpufreq_remove_update_util_hook(int cpu);
3608 #endif /* CONFIG_CPU_FREQ */
3609 
3610 #endif
3611 

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