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Linux/include/linux/sched.h

  1 #ifndef _LINUX_SCHED_H
  2 #define _LINUX_SCHED_H
  3 
  4 #include <uapi/linux/sched.h>
  5 
  6 #include <linux/sched/prio.h>
  7 
  8 
  9 struct sched_param {
 10         int sched_priority;
 11 };
 12 
 13 #include <asm/param.h>  /* for HZ */
 14 
 15 #include <linux/capability.h>
 16 #include <linux/threads.h>
 17 #include <linux/kernel.h>
 18 #include <linux/types.h>
 19 #include <linux/timex.h>
 20 #include <linux/jiffies.h>
 21 #include <linux/plist.h>
 22 #include <linux/rbtree.h>
 23 #include <linux/thread_info.h>
 24 #include <linux/cpumask.h>
 25 #include <linux/errno.h>
 26 #include <linux/nodemask.h>
 27 #include <linux/mm_types.h>
 28 #include <linux/preempt_mask.h>
 29 
 30 #include <asm/page.h>
 31 #include <asm/ptrace.h>
 32 #include <linux/cputime.h>
 33 
 34 #include <linux/smp.h>
 35 #include <linux/sem.h>
 36 #include <linux/shm.h>
 37 #include <linux/signal.h>
 38 #include <linux/compiler.h>
 39 #include <linux/completion.h>
 40 #include <linux/pid.h>
 41 #include <linux/percpu.h>
 42 #include <linux/topology.h>
 43 #include <linux/proportions.h>
 44 #include <linux/seccomp.h>
 45 #include <linux/rcupdate.h>
 46 #include <linux/rculist.h>
 47 #include <linux/rtmutex.h>
 48 
 49 #include <linux/time.h>
 50 #include <linux/param.h>
 51 #include <linux/resource.h>
 52 #include <linux/timer.h>
 53 #include <linux/hrtimer.h>
 54 #include <linux/task_io_accounting.h>
 55 #include <linux/latencytop.h>
 56 #include <linux/cred.h>
 57 #include <linux/llist.h>
 58 #include <linux/uidgid.h>
 59 #include <linux/gfp.h>
 60 #include <linux/magic.h>
 61 
 62 #include <asm/processor.h>
 63 
 64 #define SCHED_ATTR_SIZE_VER0    48      /* sizeof first published struct */
 65 
 66 /*
 67  * Extended scheduling parameters data structure.
 68  *
 69  * This is needed because the original struct sched_param can not be
 70  * altered without introducing ABI issues with legacy applications
 71  * (e.g., in sched_getparam()).
 72  *
 73  * However, the possibility of specifying more than just a priority for
 74  * the tasks may be useful for a wide variety of application fields, e.g.,
 75  * multimedia, streaming, automation and control, and many others.
 76  *
 77  * This variant (sched_attr) is meant at describing a so-called
 78  * sporadic time-constrained task. In such model a task is specified by:
 79  *  - the activation period or minimum instance inter-arrival time;
 80  *  - the maximum (or average, depending on the actual scheduling
 81  *    discipline) computation time of all instances, a.k.a. runtime;
 82  *  - the deadline (relative to the actual activation time) of each
 83  *    instance.
 84  * Very briefly, a periodic (sporadic) task asks for the execution of
 85  * some specific computation --which is typically called an instance--
 86  * (at most) every period. Moreover, each instance typically lasts no more
 87  * than the runtime and must be completed by time instant t equal to
 88  * the instance activation time + the deadline.
 89  *
 90  * This is reflected by the actual fields of the sched_attr structure:
 91  *
 92  *  @size               size of the structure, for fwd/bwd compat.
 93  *
 94  *  @sched_policy       task's scheduling policy
 95  *  @sched_flags        for customizing the scheduler behaviour
 96  *  @sched_nice         task's nice value      (SCHED_NORMAL/BATCH)
 97  *  @sched_priority     task's static priority (SCHED_FIFO/RR)
 98  *  @sched_deadline     representative of the task's deadline
 99  *  @sched_runtime      representative of the task's runtime
100  *  @sched_period       representative of the task's period
101  *
102  * Given this task model, there are a multiplicity of scheduling algorithms
103  * and policies, that can be used to ensure all the tasks will make their
104  * timing constraints.
105  *
106  * As of now, the SCHED_DEADLINE policy (sched_dl scheduling class) is the
107  * only user of this new interface. More information about the algorithm
108  * available in the scheduling class file or in Documentation/.
109  */
110 struct sched_attr {
111         u32 size;
112 
113         u32 sched_policy;
114         u64 sched_flags;
115 
116         /* SCHED_NORMAL, SCHED_BATCH */
117         s32 sched_nice;
118 
119         /* SCHED_FIFO, SCHED_RR */
120         u32 sched_priority;
121 
122         /* SCHED_DEADLINE */
123         u64 sched_runtime;
124         u64 sched_deadline;
125         u64 sched_period;
126 };
127 
128 struct exec_domain;
129 struct futex_pi_state;
130 struct robust_list_head;
131 struct bio_list;
132 struct fs_struct;
133 struct perf_event_context;
134 struct blk_plug;
135 struct filename;
136 
137 #define VMACACHE_BITS 2
138 #define VMACACHE_SIZE (1U << VMACACHE_BITS)
139 #define VMACACHE_MASK (VMACACHE_SIZE - 1)
140 
141 /*
142  * These are the constant used to fake the fixed-point load-average
143  * counting. Some notes:
144  *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
145  *    a load-average precision of 10 bits integer + 11 bits fractional
146  *  - if you want to count load-averages more often, you need more
147  *    precision, or rounding will get you. With 2-second counting freq,
148  *    the EXP_n values would be 1981, 2034 and 2043 if still using only
149  *    11 bit fractions.
150  */
151 extern unsigned long avenrun[];         /* Load averages */
152 extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
153 
154 #define FSHIFT          11              /* nr of bits of precision */
155 #define FIXED_1         (1<<FSHIFT)     /* 1.0 as fixed-point */
156 #define LOAD_FREQ       (5*HZ+1)        /* 5 sec intervals */
157 #define EXP_1           1884            /* 1/exp(5sec/1min) as fixed-point */
158 #define EXP_5           2014            /* 1/exp(5sec/5min) */
159 #define EXP_15          2037            /* 1/exp(5sec/15min) */
160 
161 #define CALC_LOAD(load,exp,n) \
162         load *= exp; \
163         load += n*(FIXED_1-exp); \
164         load >>= FSHIFT;
165 
166 extern unsigned long total_forks;
167 extern int nr_threads;
168 DECLARE_PER_CPU(unsigned long, process_counts);
169 extern int nr_processes(void);
170 extern unsigned long nr_running(void);
171 extern bool single_task_running(void);
172 extern unsigned long nr_iowait(void);
173 extern unsigned long nr_iowait_cpu(int cpu);
174 extern void get_iowait_load(unsigned long *nr_waiters, unsigned long *load);
175 
176 extern void calc_global_load(unsigned long ticks);
177 extern void update_cpu_load_nohz(void);
178 
179 extern unsigned long get_parent_ip(unsigned long addr);
180 
181 extern void dump_cpu_task(int cpu);
182 
183 struct seq_file;
184 struct cfs_rq;
185 struct task_group;
186 #ifdef CONFIG_SCHED_DEBUG
187 extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
188 extern void proc_sched_set_task(struct task_struct *p);
189 extern void
190 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
191 #endif
192 
193 /*
194  * Task state bitmask. NOTE! These bits are also
195  * encoded in fs/proc/array.c: get_task_state().
196  *
197  * We have two separate sets of flags: task->state
198  * is about runnability, while task->exit_state are
199  * about the task exiting. Confusing, but this way
200  * modifying one set can't modify the other one by
201  * mistake.
202  */
203 #define TASK_RUNNING            0
204 #define TASK_INTERRUPTIBLE      1
205 #define TASK_UNINTERRUPTIBLE    2
206 #define __TASK_STOPPED          4
207 #define __TASK_TRACED           8
208 /* in tsk->exit_state */
209 #define EXIT_DEAD               16
210 #define EXIT_ZOMBIE             32
211 #define EXIT_TRACE              (EXIT_ZOMBIE | EXIT_DEAD)
212 /* in tsk->state again */
213 #define TASK_DEAD               64
214 #define TASK_WAKEKILL           128
215 #define TASK_WAKING             256
216 #define TASK_PARKED             512
217 #define TASK_STATE_MAX          1024
218 
219 #define TASK_STATE_TO_CHAR_STR "RSDTtXZxKWP"
220 
221 extern char ___assert_task_state[1 - 2*!!(
222                 sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
223 
224 /* Convenience macros for the sake of set_task_state */
225 #define TASK_KILLABLE           (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
226 #define TASK_STOPPED            (TASK_WAKEKILL | __TASK_STOPPED)
227 #define TASK_TRACED             (TASK_WAKEKILL | __TASK_TRACED)
228 
229 /* Convenience macros for the sake of wake_up */
230 #define TASK_NORMAL             (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
231 #define TASK_ALL                (TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
232 
233 /* get_task_state() */
234 #define TASK_REPORT             (TASK_RUNNING | TASK_INTERRUPTIBLE | \
235                                  TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
236                                  __TASK_TRACED | EXIT_ZOMBIE | EXIT_DEAD)
237 
238 #define task_is_traced(task)    ((task->state & __TASK_TRACED) != 0)
239 #define task_is_stopped(task)   ((task->state & __TASK_STOPPED) != 0)
240 #define task_is_stopped_or_traced(task) \
241                         ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
242 #define task_contributes_to_load(task)  \
243                                 ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
244                                  (task->flags & PF_FROZEN) == 0)
245 
246 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
247 
248 #define __set_task_state(tsk, state_value)                      \
249         do {                                                    \
250                 (tsk)->task_state_change = _THIS_IP_;           \
251                 (tsk)->state = (state_value);                   \
252         } while (0)
253 #define set_task_state(tsk, state_value)                        \
254         do {                                                    \
255                 (tsk)->task_state_change = _THIS_IP_;           \
256                 set_mb((tsk)->state, (state_value));            \
257         } while (0)
258 
259 /*
260  * set_current_state() includes a barrier so that the write of current->state
261  * is correctly serialised wrt the caller's subsequent test of whether to
262  * actually sleep:
263  *
264  *      set_current_state(TASK_UNINTERRUPTIBLE);
265  *      if (do_i_need_to_sleep())
266  *              schedule();
267  *
268  * If the caller does not need such serialisation then use __set_current_state()
269  */
270 #define __set_current_state(state_value)                        \
271         do {                                                    \
272                 current->task_state_change = _THIS_IP_;         \
273                 current->state = (state_value);                 \
274         } while (0)
275 #define set_current_state(state_value)                          \
276         do {                                                    \
277                 current->task_state_change = _THIS_IP_;         \
278                 set_mb(current->state, (state_value));          \
279         } while (0)
280 
281 #else
282 
283 #define __set_task_state(tsk, state_value)              \
284         do { (tsk)->state = (state_value); } while (0)
285 #define set_task_state(tsk, state_value)                \
286         set_mb((tsk)->state, (state_value))
287 
288 /*
289  * set_current_state() includes a barrier so that the write of current->state
290  * is correctly serialised wrt the caller's subsequent test of whether to
291  * actually sleep:
292  *
293  *      set_current_state(TASK_UNINTERRUPTIBLE);
294  *      if (do_i_need_to_sleep())
295  *              schedule();
296  *
297  * If the caller does not need such serialisation then use __set_current_state()
298  */
299 #define __set_current_state(state_value)                \
300         do { current->state = (state_value); } while (0)
301 #define set_current_state(state_value)                  \
302         set_mb(current->state, (state_value))
303 
304 #endif
305 
306 /* Task command name length */
307 #define TASK_COMM_LEN 16
308 
309 #include <linux/spinlock.h>
310 
311 /*
312  * This serializes "schedule()" and also protects
313  * the run-queue from deletions/modifications (but
314  * _adding_ to the beginning of the run-queue has
315  * a separate lock).
316  */
317 extern rwlock_t tasklist_lock;
318 extern spinlock_t mmlist_lock;
319 
320 struct task_struct;
321 
322 #ifdef CONFIG_PROVE_RCU
323 extern int lockdep_tasklist_lock_is_held(void);
324 #endif /* #ifdef CONFIG_PROVE_RCU */
325 
326 extern void sched_init(void);
327 extern void sched_init_smp(void);
328 extern asmlinkage void schedule_tail(struct task_struct *prev);
329 extern void init_idle(struct task_struct *idle, int cpu);
330 extern void init_idle_bootup_task(struct task_struct *idle);
331 
332 extern int runqueue_is_locked(int cpu);
333 
334 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
335 extern void nohz_balance_enter_idle(int cpu);
336 extern void set_cpu_sd_state_idle(void);
337 extern int get_nohz_timer_target(int pinned);
338 #else
339 static inline void nohz_balance_enter_idle(int cpu) { }
340 static inline void set_cpu_sd_state_idle(void) { }
341 static inline int get_nohz_timer_target(int pinned)
342 {
343         return smp_processor_id();
344 }
345 #endif
346 
347 /*
348  * Only dump TASK_* tasks. (0 for all tasks)
349  */
350 extern void show_state_filter(unsigned long state_filter);
351 
352 static inline void show_state(void)
353 {
354         show_state_filter(0);
355 }
356 
357 extern void show_regs(struct pt_regs *);
358 
359 /*
360  * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
361  * task), SP is the stack pointer of the first frame that should be shown in the back
362  * trace (or NULL if the entire call-chain of the task should be shown).
363  */
364 extern void show_stack(struct task_struct *task, unsigned long *sp);
365 
366 extern void cpu_init (void);
367 extern void trap_init(void);
368 extern void update_process_times(int user);
369 extern void scheduler_tick(void);
370 
371 extern void sched_show_task(struct task_struct *p);
372 
373 #ifdef CONFIG_LOCKUP_DETECTOR
374 extern void touch_softlockup_watchdog(void);
375 extern void touch_softlockup_watchdog_sync(void);
376 extern void touch_all_softlockup_watchdogs(void);
377 extern int proc_dowatchdog_thresh(struct ctl_table *table, int write,
378                                   void __user *buffer,
379                                   size_t *lenp, loff_t *ppos);
380 extern unsigned int  softlockup_panic;
381 void lockup_detector_init(void);
382 #else
383 static inline void touch_softlockup_watchdog(void)
384 {
385 }
386 static inline void touch_softlockup_watchdog_sync(void)
387 {
388 }
389 static inline void touch_all_softlockup_watchdogs(void)
390 {
391 }
392 static inline void lockup_detector_init(void)
393 {
394 }
395 #endif
396 
397 #ifdef CONFIG_DETECT_HUNG_TASK
398 void reset_hung_task_detector(void);
399 #else
400 static inline void reset_hung_task_detector(void)
401 {
402 }
403 #endif
404 
405 /* Attach to any functions which should be ignored in wchan output. */
406 #define __sched         __attribute__((__section__(".sched.text")))
407 
408 /* Linker adds these: start and end of __sched functions */
409 extern char __sched_text_start[], __sched_text_end[];
410 
411 /* Is this address in the __sched functions? */
412 extern int in_sched_functions(unsigned long addr);
413 
414 #define MAX_SCHEDULE_TIMEOUT    LONG_MAX
415 extern signed long schedule_timeout(signed long timeout);
416 extern signed long schedule_timeout_interruptible(signed long timeout);
417 extern signed long schedule_timeout_killable(signed long timeout);
418 extern signed long schedule_timeout_uninterruptible(signed long timeout);
419 asmlinkage void schedule(void);
420 extern void schedule_preempt_disabled(void);
421 
422 extern long io_schedule_timeout(long timeout);
423 
424 static inline void io_schedule(void)
425 {
426         io_schedule_timeout(MAX_SCHEDULE_TIMEOUT);
427 }
428 
429 struct nsproxy;
430 struct user_namespace;
431 
432 #ifdef CONFIG_MMU
433 extern void arch_pick_mmap_layout(struct mm_struct *mm);
434 extern unsigned long
435 arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
436                        unsigned long, unsigned long);
437 extern unsigned long
438 arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
439                           unsigned long len, unsigned long pgoff,
440                           unsigned long flags);
441 #else
442 static inline void arch_pick_mmap_layout(struct mm_struct *mm) {}
443 #endif
444 
445 #define SUID_DUMP_DISABLE       0       /* No setuid dumping */
446 #define SUID_DUMP_USER          1       /* Dump as user of process */
447 #define SUID_DUMP_ROOT          2       /* Dump as root */
448 
449 /* mm flags */
450 
451 /* for SUID_DUMP_* above */
452 #define MMF_DUMPABLE_BITS 2
453 #define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
454 
455 extern void set_dumpable(struct mm_struct *mm, int value);
456 /*
457  * This returns the actual value of the suid_dumpable flag. For things
458  * that are using this for checking for privilege transitions, it must
459  * test against SUID_DUMP_USER rather than treating it as a boolean
460  * value.
461  */
462 static inline int __get_dumpable(unsigned long mm_flags)
463 {
464         return mm_flags & MMF_DUMPABLE_MASK;
465 }
466 
467 static inline int get_dumpable(struct mm_struct *mm)
468 {
469         return __get_dumpable(mm->flags);
470 }
471 
472 /* coredump filter bits */
473 #define MMF_DUMP_ANON_PRIVATE   2
474 #define MMF_DUMP_ANON_SHARED    3
475 #define MMF_DUMP_MAPPED_PRIVATE 4
476 #define MMF_DUMP_MAPPED_SHARED  5
477 #define MMF_DUMP_ELF_HEADERS    6
478 #define MMF_DUMP_HUGETLB_PRIVATE 7
479 #define MMF_DUMP_HUGETLB_SHARED  8
480 
481 #define MMF_DUMP_FILTER_SHIFT   MMF_DUMPABLE_BITS
482 #define MMF_DUMP_FILTER_BITS    7
483 #define MMF_DUMP_FILTER_MASK \
484         (((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
485 #define MMF_DUMP_FILTER_DEFAULT \
486         ((1 << MMF_DUMP_ANON_PRIVATE) | (1 << MMF_DUMP_ANON_SHARED) |\
487          (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
488 
489 #ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
490 # define MMF_DUMP_MASK_DEFAULT_ELF      (1 << MMF_DUMP_ELF_HEADERS)
491 #else
492 # define MMF_DUMP_MASK_DEFAULT_ELF      0
493 #endif
494                                         /* leave room for more dump flags */
495 #define MMF_VM_MERGEABLE        16      /* KSM may merge identical pages */
496 #define MMF_VM_HUGEPAGE         17      /* set when VM_HUGEPAGE is set on vma */
497 #define MMF_EXE_FILE_CHANGED    18      /* see prctl_set_mm_exe_file() */
498 
499 #define MMF_HAS_UPROBES         19      /* has uprobes */
500 #define MMF_RECALC_UPROBES      20      /* MMF_HAS_UPROBES can be wrong */
501 
502 #define MMF_INIT_MASK           (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
503 
504 struct sighand_struct {
505         atomic_t                count;
506         struct k_sigaction      action[_NSIG];
507         spinlock_t              siglock;
508         wait_queue_head_t       signalfd_wqh;
509 };
510 
511 struct pacct_struct {
512         int                     ac_flag;
513         long                    ac_exitcode;
514         unsigned long           ac_mem;
515         cputime_t               ac_utime, ac_stime;
516         unsigned long           ac_minflt, ac_majflt;
517 };
518 
519 struct cpu_itimer {
520         cputime_t expires;
521         cputime_t incr;
522         u32 error;
523         u32 incr_error;
524 };
525 
526 /**
527  * struct cputime - snaphsot of system and user cputime
528  * @utime: time spent in user mode
529  * @stime: time spent in system mode
530  *
531  * Gathers a generic snapshot of user and system time.
532  */
533 struct cputime {
534         cputime_t utime;
535         cputime_t stime;
536 };
537 
538 /**
539  * struct task_cputime - collected CPU time counts
540  * @utime:              time spent in user mode, in &cputime_t units
541  * @stime:              time spent in kernel mode, in &cputime_t units
542  * @sum_exec_runtime:   total time spent on the CPU, in nanoseconds
543  *
544  * This is an extension of struct cputime that includes the total runtime
545  * spent by the task from the scheduler point of view.
546  *
547  * As a result, this structure groups together three kinds of CPU time
548  * that are tracked for threads and thread groups.  Most things considering
549  * CPU time want to group these counts together and treat all three
550  * of them in parallel.
551  */
552 struct task_cputime {
553         cputime_t utime;
554         cputime_t stime;
555         unsigned long long sum_exec_runtime;
556 };
557 /* Alternate field names when used to cache expirations. */
558 #define prof_exp        stime
559 #define virt_exp        utime
560 #define sched_exp       sum_exec_runtime
561 
562 #define INIT_CPUTIME    \
563         (struct task_cputime) {                                 \
564                 .utime = 0,                                     \
565                 .stime = 0,                                     \
566                 .sum_exec_runtime = 0,                          \
567         }
568 
569 #ifdef CONFIG_PREEMPT_COUNT
570 #define PREEMPT_DISABLED        (1 + PREEMPT_ENABLED)
571 #else
572 #define PREEMPT_DISABLED        PREEMPT_ENABLED
573 #endif
574 
575 /*
576  * Disable preemption until the scheduler is running.
577  * Reset by start_kernel()->sched_init()->init_idle().
578  *
579  * We include PREEMPT_ACTIVE to avoid cond_resched() from working
580  * before the scheduler is active -- see should_resched().
581  */
582 #define INIT_PREEMPT_COUNT      (PREEMPT_DISABLED + PREEMPT_ACTIVE)
583 
584 /**
585  * struct thread_group_cputimer - thread group interval timer counts
586  * @cputime:            thread group interval timers.
587  * @running:            non-zero when there are timers running and
588  *                      @cputime receives updates.
589  * @lock:               lock for fields in this struct.
590  *
591  * This structure contains the version of task_cputime, above, that is
592  * used for thread group CPU timer calculations.
593  */
594 struct thread_group_cputimer {
595         struct task_cputime cputime;
596         int running;
597         raw_spinlock_t lock;
598 };
599 
600 #include <linux/rwsem.h>
601 struct autogroup;
602 
603 /*
604  * NOTE! "signal_struct" does not have its own
605  * locking, because a shared signal_struct always
606  * implies a shared sighand_struct, so locking
607  * sighand_struct is always a proper superset of
608  * the locking of signal_struct.
609  */
610 struct signal_struct {
611         atomic_t                sigcnt;
612         atomic_t                live;
613         int                     nr_threads;
614         struct list_head        thread_head;
615 
616         wait_queue_head_t       wait_chldexit;  /* for wait4() */
617 
618         /* current thread group signal load-balancing target: */
619         struct task_struct      *curr_target;
620 
621         /* shared signal handling: */
622         struct sigpending       shared_pending;
623 
624         /* thread group exit support */
625         int                     group_exit_code;
626         /* overloaded:
627          * - notify group_exit_task when ->count is equal to notify_count
628          * - everyone except group_exit_task is stopped during signal delivery
629          *   of fatal signals, group_exit_task processes the signal.
630          */
631         int                     notify_count;
632         struct task_struct      *group_exit_task;
633 
634         /* thread group stop support, overloads group_exit_code too */
635         int                     group_stop_count;
636         unsigned int            flags; /* see SIGNAL_* flags below */
637 
638         /*
639          * PR_SET_CHILD_SUBREAPER marks a process, like a service
640          * manager, to re-parent orphan (double-forking) child processes
641          * to this process instead of 'init'. The service manager is
642          * able to receive SIGCHLD signals and is able to investigate
643          * the process until it calls wait(). All children of this
644          * process will inherit a flag if they should look for a
645          * child_subreaper process at exit.
646          */
647         unsigned int            is_child_subreaper:1;
648         unsigned int            has_child_subreaper:1;
649 
650         /* POSIX.1b Interval Timers */
651         int                     posix_timer_id;
652         struct list_head        posix_timers;
653 
654         /* ITIMER_REAL timer for the process */
655         struct hrtimer real_timer;
656         struct pid *leader_pid;
657         ktime_t it_real_incr;
658 
659         /*
660          * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
661          * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
662          * values are defined to 0 and 1 respectively
663          */
664         struct cpu_itimer it[2];
665 
666         /*
667          * Thread group totals for process CPU timers.
668          * See thread_group_cputimer(), et al, for details.
669          */
670         struct thread_group_cputimer cputimer;
671 
672         /* Earliest-expiration cache. */
673         struct task_cputime cputime_expires;
674 
675         struct list_head cpu_timers[3];
676 
677         struct pid *tty_old_pgrp;
678 
679         /* boolean value for session group leader */
680         int leader;
681 
682         struct tty_struct *tty; /* NULL if no tty */
683 
684 #ifdef CONFIG_SCHED_AUTOGROUP
685         struct autogroup *autogroup;
686 #endif
687         /*
688          * Cumulative resource counters for dead threads in the group,
689          * and for reaped dead child processes forked by this group.
690          * Live threads maintain their own counters and add to these
691          * in __exit_signal, except for the group leader.
692          */
693         seqlock_t stats_lock;
694         cputime_t utime, stime, cutime, cstime;
695         cputime_t gtime;
696         cputime_t cgtime;
697 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
698         struct cputime prev_cputime;
699 #endif
700         unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
701         unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
702         unsigned long inblock, oublock, cinblock, coublock;
703         unsigned long maxrss, cmaxrss;
704         struct task_io_accounting ioac;
705 
706         /*
707          * Cumulative ns of schedule CPU time fo dead threads in the
708          * group, not including a zombie group leader, (This only differs
709          * from jiffies_to_ns(utime + stime) if sched_clock uses something
710          * other than jiffies.)
711          */
712         unsigned long long sum_sched_runtime;
713 
714         /*
715          * We don't bother to synchronize most readers of this at all,
716          * because there is no reader checking a limit that actually needs
717          * to get both rlim_cur and rlim_max atomically, and either one
718          * alone is a single word that can safely be read normally.
719          * getrlimit/setrlimit use task_lock(current->group_leader) to
720          * protect this instead of the siglock, because they really
721          * have no need to disable irqs.
722          */
723         struct rlimit rlim[RLIM_NLIMITS];
724 
725 #ifdef CONFIG_BSD_PROCESS_ACCT
726         struct pacct_struct pacct;      /* per-process accounting information */
727 #endif
728 #ifdef CONFIG_TASKSTATS
729         struct taskstats *stats;
730 #endif
731 #ifdef CONFIG_AUDIT
732         unsigned audit_tty;
733         unsigned audit_tty_log_passwd;
734         struct tty_audit_buf *tty_audit_buf;
735 #endif
736 #ifdef CONFIG_CGROUPS
737         /*
738          * group_rwsem prevents new tasks from entering the threadgroup and
739          * member tasks from exiting,a more specifically, setting of
740          * PF_EXITING.  fork and exit paths are protected with this rwsem
741          * using threadgroup_change_begin/end().  Users which require
742          * threadgroup to remain stable should use threadgroup_[un]lock()
743          * which also takes care of exec path.  Currently, cgroup is the
744          * only user.
745          */
746         struct rw_semaphore group_rwsem;
747 #endif
748 
749         oom_flags_t oom_flags;
750         short oom_score_adj;            /* OOM kill score adjustment */
751         short oom_score_adj_min;        /* OOM kill score adjustment min value.
752                                          * Only settable by CAP_SYS_RESOURCE. */
753 
754         struct mutex cred_guard_mutex;  /* guard against foreign influences on
755                                          * credential calculations
756                                          * (notably. ptrace) */
757 };
758 
759 /*
760  * Bits in flags field of signal_struct.
761  */
762 #define SIGNAL_STOP_STOPPED     0x00000001 /* job control stop in effect */
763 #define SIGNAL_STOP_CONTINUED   0x00000002 /* SIGCONT since WCONTINUED reap */
764 #define SIGNAL_GROUP_EXIT       0x00000004 /* group exit in progress */
765 #define SIGNAL_GROUP_COREDUMP   0x00000008 /* coredump in progress */
766 /*
767  * Pending notifications to parent.
768  */
769 #define SIGNAL_CLD_STOPPED      0x00000010
770 #define SIGNAL_CLD_CONTINUED    0x00000020
771 #define SIGNAL_CLD_MASK         (SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
772 
773 #define SIGNAL_UNKILLABLE       0x00000040 /* for init: ignore fatal signals */
774 
775 /* If true, all threads except ->group_exit_task have pending SIGKILL */
776 static inline int signal_group_exit(const struct signal_struct *sig)
777 {
778         return  (sig->flags & SIGNAL_GROUP_EXIT) ||
779                 (sig->group_exit_task != NULL);
780 }
781 
782 /*
783  * Some day this will be a full-fledged user tracking system..
784  */
785 struct user_struct {
786         atomic_t __count;       /* reference count */
787         atomic_t processes;     /* How many processes does this user have? */
788         atomic_t sigpending;    /* How many pending signals does this user have? */
789 #ifdef CONFIG_INOTIFY_USER
790         atomic_t inotify_watches; /* How many inotify watches does this user have? */
791         atomic_t inotify_devs;  /* How many inotify devs does this user have opened? */
792 #endif
793 #ifdef CONFIG_FANOTIFY
794         atomic_t fanotify_listeners;
795 #endif
796 #ifdef CONFIG_EPOLL
797         atomic_long_t epoll_watches; /* The number of file descriptors currently watched */
798 #endif
799 #ifdef CONFIG_POSIX_MQUEUE
800         /* protected by mq_lock */
801         unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */
802 #endif
803         unsigned long locked_shm; /* How many pages of mlocked shm ? */
804 
805 #ifdef CONFIG_KEYS
806         struct key *uid_keyring;        /* UID specific keyring */
807         struct key *session_keyring;    /* UID's default session keyring */
808 #endif
809 
810         /* Hash table maintenance information */
811         struct hlist_node uidhash_node;
812         kuid_t uid;
813 
814 #ifdef CONFIG_PERF_EVENTS
815         atomic_long_t locked_vm;
816 #endif
817 };
818 
819 extern int uids_sysfs_init(void);
820 
821 extern struct user_struct *find_user(kuid_t);
822 
823 extern struct user_struct root_user;
824 #define INIT_USER (&root_user)
825 
826 
827 struct backing_dev_info;
828 struct reclaim_state;
829 
830 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
831 struct sched_info {
832         /* cumulative counters */
833         unsigned long pcount;         /* # of times run on this cpu */
834         unsigned long long run_delay; /* time spent waiting on a runqueue */
835 
836         /* timestamps */
837         unsigned long long last_arrival,/* when we last ran on a cpu */
838                            last_queued; /* when we were last queued to run */
839 };
840 #endif /* defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) */
841 
842 #ifdef CONFIG_TASK_DELAY_ACCT
843 struct task_delay_info {
844         spinlock_t      lock;
845         unsigned int    flags;  /* Private per-task flags */
846 
847         /* For each stat XXX, add following, aligned appropriately
848          *
849          * struct timespec XXX_start, XXX_end;
850          * u64 XXX_delay;
851          * u32 XXX_count;
852          *
853          * Atomicity of updates to XXX_delay, XXX_count protected by
854          * single lock above (split into XXX_lock if contention is an issue).
855          */
856 
857         /*
858          * XXX_count is incremented on every XXX operation, the delay
859          * associated with the operation is added to XXX_delay.
860          * XXX_delay contains the accumulated delay time in nanoseconds.
861          */
862         u64 blkio_start;        /* Shared by blkio, swapin */
863         u64 blkio_delay;        /* wait for sync block io completion */
864         u64 swapin_delay;       /* wait for swapin block io completion */
865         u32 blkio_count;        /* total count of the number of sync block */
866                                 /* io operations performed */
867         u32 swapin_count;       /* total count of the number of swapin block */
868                                 /* io operations performed */
869 
870         u64 freepages_start;
871         u64 freepages_delay;    /* wait for memory reclaim */
872         u32 freepages_count;    /* total count of memory reclaim */
873 };
874 #endif  /* CONFIG_TASK_DELAY_ACCT */
875 
876 static inline int sched_info_on(void)
877 {
878 #ifdef CONFIG_SCHEDSTATS
879         return 1;
880 #elif defined(CONFIG_TASK_DELAY_ACCT)
881         extern int delayacct_on;
882         return delayacct_on;
883 #else
884         return 0;
885 #endif
886 }
887 
888 enum cpu_idle_type {
889         CPU_IDLE,
890         CPU_NOT_IDLE,
891         CPU_NEWLY_IDLE,
892         CPU_MAX_IDLE_TYPES
893 };
894 
895 /*
896  * Increase resolution of cpu_capacity calculations
897  */
898 #define SCHED_CAPACITY_SHIFT    10
899 #define SCHED_CAPACITY_SCALE    (1L << SCHED_CAPACITY_SHIFT)
900 
901 /*
902  * sched-domains (multiprocessor balancing) declarations:
903  */
904 #ifdef CONFIG_SMP
905 #define SD_LOAD_BALANCE         0x0001  /* Do load balancing on this domain. */
906 #define SD_BALANCE_NEWIDLE      0x0002  /* Balance when about to become idle */
907 #define SD_BALANCE_EXEC         0x0004  /* Balance on exec */
908 #define SD_BALANCE_FORK         0x0008  /* Balance on fork, clone */
909 #define SD_BALANCE_WAKE         0x0010  /* Balance on wakeup */
910 #define SD_WAKE_AFFINE          0x0020  /* Wake task to waking CPU */
911 #define SD_SHARE_CPUCAPACITY    0x0080  /* Domain members share cpu power */
912 #define SD_SHARE_POWERDOMAIN    0x0100  /* Domain members share power domain */
913 #define SD_SHARE_PKG_RESOURCES  0x0200  /* Domain members share cpu pkg resources */
914 #define SD_SERIALIZE            0x0400  /* Only a single load balancing instance */
915 #define SD_ASYM_PACKING         0x0800  /* Place busy groups earlier in the domain */
916 #define SD_PREFER_SIBLING       0x1000  /* Prefer to place tasks in a sibling domain */
917 #define SD_OVERLAP              0x2000  /* sched_domains of this level overlap */
918 #define SD_NUMA                 0x4000  /* cross-node balancing */
919 
920 #ifdef CONFIG_SCHED_SMT
921 static inline int cpu_smt_flags(void)
922 {
923         return SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
924 }
925 #endif
926 
927 #ifdef CONFIG_SCHED_MC
928 static inline int cpu_core_flags(void)
929 {
930         return SD_SHARE_PKG_RESOURCES;
931 }
932 #endif
933 
934 #ifdef CONFIG_NUMA
935 static inline int cpu_numa_flags(void)
936 {
937         return SD_NUMA;
938 }
939 #endif
940 
941 struct sched_domain_attr {
942         int relax_domain_level;
943 };
944 
945 #define SD_ATTR_INIT    (struct sched_domain_attr) {    \
946         .relax_domain_level = -1,                       \
947 }
948 
949 extern int sched_domain_level_max;
950 
951 struct sched_group;
952 
953 struct sched_domain {
954         /* These fields must be setup */
955         struct sched_domain *parent;    /* top domain must be null terminated */
956         struct sched_domain *child;     /* bottom domain must be null terminated */
957         struct sched_group *groups;     /* the balancing groups of the domain */
958         unsigned long min_interval;     /* Minimum balance interval ms */
959         unsigned long max_interval;     /* Maximum balance interval ms */
960         unsigned int busy_factor;       /* less balancing by factor if busy */
961         unsigned int imbalance_pct;     /* No balance until over watermark */
962         unsigned int cache_nice_tries;  /* Leave cache hot tasks for # tries */
963         unsigned int busy_idx;
964         unsigned int idle_idx;
965         unsigned int newidle_idx;
966         unsigned int wake_idx;
967         unsigned int forkexec_idx;
968         unsigned int smt_gain;
969 
970         int nohz_idle;                  /* NOHZ IDLE status */
971         int flags;                      /* See SD_* */
972         int level;
973 
974         /* Runtime fields. */
975         unsigned long last_balance;     /* init to jiffies. units in jiffies */
976         unsigned int balance_interval;  /* initialise to 1. units in ms. */
977         unsigned int nr_balance_failed; /* initialise to 0 */
978 
979         /* idle_balance() stats */
980         u64 max_newidle_lb_cost;
981         unsigned long next_decay_max_lb_cost;
982 
983 #ifdef CONFIG_SCHEDSTATS
984         /* load_balance() stats */
985         unsigned int lb_count[CPU_MAX_IDLE_TYPES];
986         unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
987         unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
988         unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
989         unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
990         unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
991         unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
992         unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
993 
994         /* Active load balancing */
995         unsigned int alb_count;
996         unsigned int alb_failed;
997         unsigned int alb_pushed;
998 
999         /* SD_BALANCE_EXEC stats */
1000         unsigned int sbe_count;
1001         unsigned int sbe_balanced;
1002         unsigned int sbe_pushed;
1003 
1004         /* SD_BALANCE_FORK stats */
1005         unsigned int sbf_count;
1006         unsigned int sbf_balanced;
1007         unsigned int sbf_pushed;
1008 
1009         /* try_to_wake_up() stats */
1010         unsigned int ttwu_wake_remote;
1011         unsigned int ttwu_move_affine;
1012         unsigned int ttwu_move_balance;
1013 #endif
1014 #ifdef CONFIG_SCHED_DEBUG
1015         char *name;
1016 #endif
1017         union {
1018                 void *private;          /* used during construction */
1019                 struct rcu_head rcu;    /* used during destruction */
1020         };
1021 
1022         unsigned int span_weight;
1023         /*
1024          * Span of all CPUs in this domain.
1025          *
1026          * NOTE: this field is variable length. (Allocated dynamically
1027          * by attaching extra space to the end of the structure,
1028          * depending on how many CPUs the kernel has booted up with)
1029          */
1030         unsigned long span[0];
1031 };
1032 
1033 static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
1034 {
1035         return to_cpumask(sd->span);
1036 }
1037 
1038 extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1039                                     struct sched_domain_attr *dattr_new);
1040 
1041 /* Allocate an array of sched domains, for partition_sched_domains(). */
1042 cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
1043 void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
1044 
1045 bool cpus_share_cache(int this_cpu, int that_cpu);
1046 
1047 typedef const struct cpumask *(*sched_domain_mask_f)(int cpu);
1048 typedef int (*sched_domain_flags_f)(void);
1049 
1050 #define SDTL_OVERLAP    0x01
1051 
1052 struct sd_data {
1053         struct sched_domain **__percpu sd;
1054         struct sched_group **__percpu sg;
1055         struct sched_group_capacity **__percpu sgc;
1056 };
1057 
1058 struct sched_domain_topology_level {
1059         sched_domain_mask_f mask;
1060         sched_domain_flags_f sd_flags;
1061         int                 flags;
1062         int                 numa_level;
1063         struct sd_data      data;
1064 #ifdef CONFIG_SCHED_DEBUG
1065         char                *name;
1066 #endif
1067 };
1068 
1069 extern struct sched_domain_topology_level *sched_domain_topology;
1070 
1071 extern void set_sched_topology(struct sched_domain_topology_level *tl);
1072 extern void wake_up_if_idle(int cpu);
1073 
1074 #ifdef CONFIG_SCHED_DEBUG
1075 # define SD_INIT_NAME(type)             .name = #type
1076 #else
1077 # define SD_INIT_NAME(type)
1078 #endif
1079 
1080 #else /* CONFIG_SMP */
1081 
1082 struct sched_domain_attr;
1083 
1084 static inline void
1085 partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1086                         struct sched_domain_attr *dattr_new)
1087 {
1088 }
1089 
1090 static inline bool cpus_share_cache(int this_cpu, int that_cpu)
1091 {
1092         return true;
1093 }
1094 
1095 #endif  /* !CONFIG_SMP */
1096 
1097 
1098 struct io_context;                      /* See blkdev.h */
1099 
1100 
1101 #ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
1102 extern void prefetch_stack(struct task_struct *t);
1103 #else
1104 static inline void prefetch_stack(struct task_struct *t) { }
1105 #endif
1106 
1107 struct audit_context;           /* See audit.c */
1108 struct mempolicy;
1109 struct pipe_inode_info;
1110 struct uts_namespace;
1111 
1112 struct load_weight {
1113         unsigned long weight;
1114         u32 inv_weight;
1115 };
1116 
1117 struct sched_avg {
1118         /*
1119          * These sums represent an infinite geometric series and so are bound
1120          * above by 1024/(1-y).  Thus we only need a u32 to store them for all
1121          * choices of y < 1-2^(-32)*1024.
1122          */
1123         u32 runnable_avg_sum, runnable_avg_period;
1124         u64 last_runnable_update;
1125         s64 decay_count;
1126         unsigned long load_avg_contrib;
1127 };
1128 
1129 #ifdef CONFIG_SCHEDSTATS
1130 struct sched_statistics {
1131         u64                     wait_start;
1132         u64                     wait_max;
1133         u64                     wait_count;
1134         u64                     wait_sum;
1135         u64                     iowait_count;
1136         u64                     iowait_sum;
1137 
1138         u64                     sleep_start;
1139         u64                     sleep_max;
1140         s64                     sum_sleep_runtime;
1141 
1142         u64                     block_start;
1143         u64                     block_max;
1144         u64                     exec_max;
1145         u64                     slice_max;
1146 
1147         u64                     nr_migrations_cold;
1148         u64                     nr_failed_migrations_affine;
1149         u64                     nr_failed_migrations_running;
1150         u64                     nr_failed_migrations_hot;
1151         u64                     nr_forced_migrations;
1152 
1153         u64                     nr_wakeups;
1154         u64                     nr_wakeups_sync;
1155         u64                     nr_wakeups_migrate;
1156         u64                     nr_wakeups_local;
1157         u64                     nr_wakeups_remote;
1158         u64                     nr_wakeups_affine;
1159         u64                     nr_wakeups_affine_attempts;
1160         u64                     nr_wakeups_passive;
1161         u64                     nr_wakeups_idle;
1162 };
1163 #endif
1164 
1165 struct sched_entity {
1166         struct load_weight      load;           /* for load-balancing */
1167         struct rb_node          run_node;
1168         struct list_head        group_node;
1169         unsigned int            on_rq;
1170 
1171         u64                     exec_start;
1172         u64                     sum_exec_runtime;
1173         u64                     vruntime;
1174         u64                     prev_sum_exec_runtime;
1175 
1176         u64                     nr_migrations;
1177 
1178 #ifdef CONFIG_SCHEDSTATS
1179         struct sched_statistics statistics;
1180 #endif
1181 
1182 #ifdef CONFIG_FAIR_GROUP_SCHED
1183         int                     depth;
1184         struct sched_entity     *parent;
1185         /* rq on which this entity is (to be) queued: */
1186         struct cfs_rq           *cfs_rq;
1187         /* rq "owned" by this entity/group: */
1188         struct cfs_rq           *my_q;
1189 #endif
1190 
1191 #ifdef CONFIG_SMP
1192         /* Per-entity load-tracking */
1193         struct sched_avg        avg;
1194 #endif
1195 };
1196 
1197 struct sched_rt_entity {
1198         struct list_head run_list;
1199         unsigned long timeout;
1200         unsigned long watchdog_stamp;
1201         unsigned int time_slice;
1202 
1203         struct sched_rt_entity *back;
1204 #ifdef CONFIG_RT_GROUP_SCHED
1205         struct sched_rt_entity  *parent;
1206         /* rq on which this entity is (to be) queued: */
1207         struct rt_rq            *rt_rq;
1208         /* rq "owned" by this entity/group: */
1209         struct rt_rq            *my_q;
1210 #endif
1211 };
1212 
1213 struct sched_dl_entity {
1214         struct rb_node  rb_node;
1215 
1216         /*
1217          * Original scheduling parameters. Copied here from sched_attr
1218          * during sched_setattr(), they will remain the same until
1219          * the next sched_setattr().
1220          */
1221         u64 dl_runtime;         /* maximum runtime for each instance    */
1222         u64 dl_deadline;        /* relative deadline of each instance   */
1223         u64 dl_period;          /* separation of two instances (period) */
1224         u64 dl_bw;              /* dl_runtime / dl_deadline             */
1225 
1226         /*
1227          * Actual scheduling parameters. Initialized with the values above,
1228          * they are continously updated during task execution. Note that
1229          * the remaining runtime could be < 0 in case we are in overrun.
1230          */
1231         s64 runtime;            /* remaining runtime for this instance  */
1232         u64 deadline;           /* absolute deadline for this instance  */
1233         unsigned int flags;     /* specifying the scheduler behaviour   */
1234 
1235         /*
1236          * Some bool flags:
1237          *
1238          * @dl_throttled tells if we exhausted the runtime. If so, the
1239          * task has to wait for a replenishment to be performed at the
1240          * next firing of dl_timer.
1241          *
1242          * @dl_new tells if a new instance arrived. If so we must
1243          * start executing it with full runtime and reset its absolute
1244          * deadline;
1245          *
1246          * @dl_boosted tells if we are boosted due to DI. If so we are
1247          * outside bandwidth enforcement mechanism (but only until we
1248          * exit the critical section);
1249          *
1250          * @dl_yielded tells if task gave up the cpu before consuming
1251          * all its available runtime during the last job.
1252          */
1253         int dl_throttled, dl_new, dl_boosted, dl_yielded;
1254 
1255         /*
1256          * Bandwidth enforcement timer. Each -deadline task has its
1257          * own bandwidth to be enforced, thus we need one timer per task.
1258          */
1259         struct hrtimer dl_timer;
1260 };
1261 
1262 union rcu_special {
1263         struct {
1264                 bool blocked;
1265                 bool need_qs;
1266         } b;
1267         short s;
1268 };
1269 struct rcu_node;
1270 
1271 enum perf_event_task_context {
1272         perf_invalid_context = -1,
1273         perf_hw_context = 0,
1274         perf_sw_context,
1275         perf_nr_task_contexts,
1276 };
1277 
1278 struct task_struct {
1279         volatile long state;    /* -1 unrunnable, 0 runnable, >0 stopped */
1280         void *stack;
1281         atomic_t usage;
1282         unsigned int flags;     /* per process flags, defined below */
1283         unsigned int ptrace;
1284 
1285 #ifdef CONFIG_SMP
1286         struct llist_node wake_entry;
1287         int on_cpu;
1288         struct task_struct *last_wakee;
1289         unsigned long wakee_flips;
1290         unsigned long wakee_flip_decay_ts;
1291 
1292         int wake_cpu;
1293 #endif
1294         int on_rq;
1295 
1296         int prio, static_prio, normal_prio;
1297         unsigned int rt_priority;
1298         const struct sched_class *sched_class;
1299         struct sched_entity se;
1300         struct sched_rt_entity rt;
1301 #ifdef CONFIG_CGROUP_SCHED
1302         struct task_group *sched_task_group;
1303 #endif
1304         struct sched_dl_entity dl;
1305 
1306 #ifdef CONFIG_PREEMPT_NOTIFIERS
1307         /* list of struct preempt_notifier: */
1308         struct hlist_head preempt_notifiers;
1309 #endif
1310 
1311 #ifdef CONFIG_BLK_DEV_IO_TRACE
1312         unsigned int btrace_seq;
1313 #endif
1314 
1315         unsigned int policy;
1316         int nr_cpus_allowed;
1317         cpumask_t cpus_allowed;
1318 
1319 #ifdef CONFIG_PREEMPT_RCU
1320         int rcu_read_lock_nesting;
1321         union rcu_special rcu_read_unlock_special;
1322         struct list_head rcu_node_entry;
1323 #endif /* #ifdef CONFIG_PREEMPT_RCU */
1324 #ifdef CONFIG_PREEMPT_RCU
1325         struct rcu_node *rcu_blocked_node;
1326 #endif /* #ifdef CONFIG_PREEMPT_RCU */
1327 #ifdef CONFIG_TASKS_RCU
1328         unsigned long rcu_tasks_nvcsw;
1329         bool rcu_tasks_holdout;
1330         struct list_head rcu_tasks_holdout_list;
1331         int rcu_tasks_idle_cpu;
1332 #endif /* #ifdef CONFIG_TASKS_RCU */
1333 
1334 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
1335         struct sched_info sched_info;
1336 #endif
1337 
1338         struct list_head tasks;
1339 #ifdef CONFIG_SMP
1340         struct plist_node pushable_tasks;
1341         struct rb_node pushable_dl_tasks;
1342 #endif
1343 
1344         struct mm_struct *mm, *active_mm;
1345 #ifdef CONFIG_COMPAT_BRK
1346         unsigned brk_randomized:1;
1347 #endif
1348         /* per-thread vma caching */
1349         u32 vmacache_seqnum;
1350         struct vm_area_struct *vmacache[VMACACHE_SIZE];
1351 #if defined(SPLIT_RSS_COUNTING)
1352         struct task_rss_stat    rss_stat;
1353 #endif
1354 /* task state */
1355         int exit_state;
1356         int exit_code, exit_signal;
1357         int pdeath_signal;  /*  The signal sent when the parent dies  */
1358         unsigned int jobctl;    /* JOBCTL_*, siglock protected */
1359 
1360         /* Used for emulating ABI behavior of previous Linux versions */
1361         unsigned int personality;
1362 
1363         unsigned in_execve:1;   /* Tell the LSMs that the process is doing an
1364                                  * execve */
1365         unsigned in_iowait:1;
1366 
1367         /* Revert to default priority/policy when forking */
1368         unsigned sched_reset_on_fork:1;
1369         unsigned sched_contributes_to_load:1;
1370 
1371 #ifdef CONFIG_MEMCG_KMEM
1372         unsigned memcg_kmem_skip_account:1;
1373 #endif
1374 
1375         unsigned long atomic_flags; /* Flags needing atomic access. */
1376 
1377         struct restart_block restart_block;
1378 
1379         pid_t pid;
1380         pid_t tgid;
1381 
1382 #ifdef CONFIG_CC_STACKPROTECTOR
1383         /* Canary value for the -fstack-protector gcc feature */
1384         unsigned long stack_canary;
1385 #endif
1386         /*
1387          * pointers to (original) parent process, youngest child, younger sibling,
1388          * older sibling, respectively.  (p->father can be replaced with
1389          * p->real_parent->pid)
1390          */
1391         struct task_struct __rcu *real_parent; /* real parent process */
1392         struct task_struct __rcu *parent; /* recipient of SIGCHLD, wait4() reports */
1393         /*
1394          * children/sibling forms the list of my natural children
1395          */
1396         struct list_head children;      /* list of my children */
1397         struct list_head sibling;       /* linkage in my parent's children list */
1398         struct task_struct *group_leader;       /* threadgroup leader */
1399 
1400         /*
1401          * ptraced is the list of tasks this task is using ptrace on.
1402          * This includes both natural children and PTRACE_ATTACH targets.
1403          * p->ptrace_entry is p's link on the p->parent->ptraced list.
1404          */
1405         struct list_head ptraced;
1406         struct list_head ptrace_entry;
1407 
1408         /* PID/PID hash table linkage. */
1409         struct pid_link pids[PIDTYPE_MAX];
1410         struct list_head thread_group;
1411         struct list_head thread_node;
1412 
1413         struct completion *vfork_done;          /* for vfork() */
1414         int __user *set_child_tid;              /* CLONE_CHILD_SETTID */
1415         int __user *clear_child_tid;            /* CLONE_CHILD_CLEARTID */
1416 
1417         cputime_t utime, stime, utimescaled, stimescaled;
1418         cputime_t gtime;
1419 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
1420         struct cputime prev_cputime;
1421 #endif
1422 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1423         seqlock_t vtime_seqlock;
1424         unsigned long long vtime_snap;
1425         enum {
1426                 VTIME_SLEEPING = 0,
1427                 VTIME_USER,
1428                 VTIME_SYS,
1429         } vtime_snap_whence;
1430 #endif
1431         unsigned long nvcsw, nivcsw; /* context switch counts */
1432         u64 start_time;         /* monotonic time in nsec */
1433         u64 real_start_time;    /* boot based time in nsec */
1434 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1435         unsigned long min_flt, maj_flt;
1436 
1437         struct task_cputime cputime_expires;
1438         struct list_head cpu_timers[3];
1439 
1440 /* process credentials */
1441         const struct cred __rcu *real_cred; /* objective and real subjective task
1442                                          * credentials (COW) */
1443         const struct cred __rcu *cred;  /* effective (overridable) subjective task
1444                                          * credentials (COW) */
1445         char comm[TASK_COMM_LEN]; /* executable name excluding path
1446                                      - access with [gs]et_task_comm (which lock
1447                                        it with task_lock())
1448                                      - initialized normally by setup_new_exec */
1449 /* file system info */
1450         int link_count, total_link_count;
1451 #ifdef CONFIG_SYSVIPC
1452 /* ipc stuff */
1453         struct sysv_sem sysvsem;
1454         struct sysv_shm sysvshm;
1455 #endif
1456 #ifdef CONFIG_DETECT_HUNG_TASK
1457 /* hung task detection */
1458         unsigned long last_switch_count;
1459 #endif
1460 /* CPU-specific state of this task */
1461         struct thread_struct thread;
1462 /* filesystem information */
1463         struct fs_struct *fs;
1464 /* open file information */
1465         struct files_struct *files;
1466 /* namespaces */
1467         struct nsproxy *nsproxy;
1468 /* signal handlers */
1469         struct signal_struct *signal;
1470         struct sighand_struct *sighand;
1471 
1472         sigset_t blocked, real_blocked;
1473         sigset_t saved_sigmask; /* restored if set_restore_sigmask() was used */
1474         struct sigpending pending;
1475 
1476         unsigned long sas_ss_sp;
1477         size_t sas_ss_size;
1478         int (*notifier)(void *priv);
1479         void *notifier_data;
1480         sigset_t *notifier_mask;
1481         struct callback_head *task_works;
1482 
1483         struct audit_context *audit_context;
1484 #ifdef CONFIG_AUDITSYSCALL
1485         kuid_t loginuid;
1486         unsigned int sessionid;
1487 #endif
1488         struct seccomp seccomp;
1489 
1490 /* Thread group tracking */
1491         u32 parent_exec_id;
1492         u32 self_exec_id;
1493 /* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1494  * mempolicy */
1495         spinlock_t alloc_lock;
1496 
1497         /* Protection of the PI data structures: */
1498         raw_spinlock_t pi_lock;
1499 
1500 #ifdef CONFIG_RT_MUTEXES
1501         /* PI waiters blocked on a rt_mutex held by this task */
1502         struct rb_root pi_waiters;
1503         struct rb_node *pi_waiters_leftmost;
1504         /* Deadlock detection and priority inheritance handling */
1505         struct rt_mutex_waiter *pi_blocked_on;
1506 #endif
1507 
1508 #ifdef CONFIG_DEBUG_MUTEXES
1509         /* mutex deadlock detection */
1510         struct mutex_waiter *blocked_on;
1511 #endif
1512 #ifdef CONFIG_TRACE_IRQFLAGS
1513         unsigned int irq_events;
1514         unsigned long hardirq_enable_ip;
1515         unsigned long hardirq_disable_ip;
1516         unsigned int hardirq_enable_event;
1517         unsigned int hardirq_disable_event;
1518         int hardirqs_enabled;
1519         int hardirq_context;
1520         unsigned long softirq_disable_ip;
1521         unsigned long softirq_enable_ip;
1522         unsigned int softirq_disable_event;
1523         unsigned int softirq_enable_event;
1524         int softirqs_enabled;
1525         int softirq_context;
1526 #endif
1527 #ifdef CONFIG_LOCKDEP
1528 # define MAX_LOCK_DEPTH 48UL
1529         u64 curr_chain_key;
1530         int lockdep_depth;
1531         unsigned int lockdep_recursion;
1532         struct held_lock held_locks[MAX_LOCK_DEPTH];
1533         gfp_t lockdep_reclaim_gfp;
1534 #endif
1535 
1536 /* journalling filesystem info */
1537         void *journal_info;
1538 
1539 /* stacked block device info */
1540         struct bio_list *bio_list;
1541 
1542 #ifdef CONFIG_BLOCK
1543 /* stack plugging */
1544         struct blk_plug *plug;
1545 #endif
1546 
1547 /* VM state */
1548         struct reclaim_state *reclaim_state;
1549 
1550         struct backing_dev_info *backing_dev_info;
1551 
1552         struct io_context *io_context;
1553 
1554         unsigned long ptrace_message;
1555         siginfo_t *last_siginfo; /* For ptrace use.  */
1556         struct task_io_accounting ioac;
1557 #if defined(CONFIG_TASK_XACCT)
1558         u64 acct_rss_mem1;      /* accumulated rss usage */
1559         u64 acct_vm_mem1;       /* accumulated virtual memory usage */
1560         cputime_t acct_timexpd; /* stime + utime since last update */
1561 #endif
1562 #ifdef CONFIG_CPUSETS
1563         nodemask_t mems_allowed;        /* Protected by alloc_lock */
1564         seqcount_t mems_allowed_seq;    /* Seqence no to catch updates */
1565         int cpuset_mem_spread_rotor;
1566         int cpuset_slab_spread_rotor;
1567 #endif
1568 #ifdef CONFIG_CGROUPS
1569         /* Control Group info protected by css_set_lock */
1570         struct css_set __rcu *cgroups;
1571         /* cg_list protected by css_set_lock and tsk->alloc_lock */
1572         struct list_head cg_list;
1573 #endif
1574 #ifdef CONFIG_FUTEX
1575         struct robust_list_head __user *robust_list;
1576 #ifdef CONFIG_COMPAT
1577         struct compat_robust_list_head __user *compat_robust_list;
1578 #endif
1579         struct list_head pi_state_list;
1580         struct futex_pi_state *pi_state_cache;
1581 #endif
1582 #ifdef CONFIG_PERF_EVENTS
1583         struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1584         struct mutex perf_event_mutex;
1585         struct list_head perf_event_list;
1586 #endif
1587 #ifdef CONFIG_DEBUG_PREEMPT
1588         unsigned long preempt_disable_ip;
1589 #endif
1590 #ifdef CONFIG_NUMA
1591         struct mempolicy *mempolicy;    /* Protected by alloc_lock */
1592         short il_next;
1593         short pref_node_fork;
1594 #endif
1595 #ifdef CONFIG_NUMA_BALANCING
1596         int numa_scan_seq;
1597         unsigned int numa_scan_period;
1598         unsigned int numa_scan_period_max;
1599         int numa_preferred_nid;
1600         unsigned long numa_migrate_retry;
1601         u64 node_stamp;                 /* migration stamp  */
1602         u64 last_task_numa_placement;
1603         u64 last_sum_exec_runtime;
1604         struct callback_head numa_work;
1605 
1606         struct list_head numa_entry;
1607         struct numa_group *numa_group;
1608 
1609         /*
1610          * numa_faults is an array split into four regions:
1611          * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1612          * in this precise order.
1613          *
1614          * faults_memory: Exponential decaying average of faults on a per-node
1615          * basis. Scheduling placement decisions are made based on these
1616          * counts. The values remain static for the duration of a PTE scan.
1617          * faults_cpu: Track the nodes the process was running on when a NUMA
1618          * hinting fault was incurred.
1619          * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1620          * during the current scan window. When the scan completes, the counts
1621          * in faults_memory and faults_cpu decay and these values are copied.
1622          */
1623         unsigned long *numa_faults;
1624         unsigned long total_numa_faults;
1625 
1626         /*
1627          * numa_faults_locality tracks if faults recorded during the last
1628          * scan window were remote/local or failed to migrate. The task scan
1629          * period is adapted based on the locality of the faults with different
1630          * weights depending on whether they were shared or private faults
1631          */
1632         unsigned long numa_faults_locality[3];
1633 
1634         unsigned long numa_pages_migrated;
1635 #endif /* CONFIG_NUMA_BALANCING */
1636 
1637         struct rcu_head rcu;
1638 
1639         /*
1640          * cache last used pipe for splice
1641          */
1642         struct pipe_inode_info *splice_pipe;
1643 
1644         struct page_frag task_frag;
1645 
1646 #ifdef  CONFIG_TASK_DELAY_ACCT
1647         struct task_delay_info *delays;
1648 #endif
1649 #ifdef CONFIG_FAULT_INJECTION
1650         int make_it_fail;
1651 #endif
1652         /*
1653          * when (nr_dirtied >= nr_dirtied_pause), it's time to call
1654          * balance_dirty_pages() for some dirty throttling pause
1655          */
1656         int nr_dirtied;
1657         int nr_dirtied_pause;
1658         unsigned long dirty_paused_when; /* start of a write-and-pause period */
1659 
1660 #ifdef CONFIG_LATENCYTOP
1661         int latency_record_count;
1662         struct latency_record latency_record[LT_SAVECOUNT];
1663 #endif
1664         /*
1665          * time slack values; these are used to round up poll() and
1666          * select() etc timeout values. These are in nanoseconds.
1667          */
1668         unsigned long timer_slack_ns;
1669         unsigned long default_timer_slack_ns;
1670 
1671 #ifdef CONFIG_KASAN
1672         unsigned int kasan_depth;
1673 #endif
1674 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1675         /* Index of current stored address in ret_stack */
1676         int curr_ret_stack;
1677         /* Stack of return addresses for return function tracing */
1678         struct ftrace_ret_stack *ret_stack;
1679         /* time stamp for last schedule */
1680         unsigned long long ftrace_timestamp;
1681         /*
1682          * Number of functions that haven't been traced
1683          * because of depth overrun.
1684          */
1685         atomic_t trace_overrun;
1686         /* Pause for the tracing */
1687         atomic_t tracing_graph_pause;
1688 #endif
1689 #ifdef CONFIG_TRACING
1690         /* state flags for use by tracers */
1691         unsigned long trace;
1692         /* bitmask and counter of trace recursion */
1693         unsigned long trace_recursion;
1694 #endif /* CONFIG_TRACING */
1695 #ifdef CONFIG_MEMCG
1696         struct memcg_oom_info {
1697                 struct mem_cgroup *memcg;
1698                 gfp_t gfp_mask;
1699                 int order;
1700                 unsigned int may_oom:1;
1701         } memcg_oom;
1702 #endif
1703 #ifdef CONFIG_UPROBES
1704         struct uprobe_task *utask;
1705 #endif
1706 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1707         unsigned int    sequential_io;
1708         unsigned int    sequential_io_avg;
1709 #endif
1710 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1711         unsigned long   task_state_change;
1712 #endif
1713 };
1714 
1715 /* Future-safe accessor for struct task_struct's cpus_allowed. */
1716 #define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
1717 
1718 #define TNF_MIGRATED    0x01
1719 #define TNF_NO_GROUP    0x02
1720 #define TNF_SHARED      0x04
1721 #define TNF_FAULT_LOCAL 0x08
1722 #define TNF_MIGRATE_FAIL 0x10
1723 
1724 #ifdef CONFIG_NUMA_BALANCING
1725 extern void task_numa_fault(int last_node, int node, int pages, int flags);
1726 extern pid_t task_numa_group_id(struct task_struct *p);
1727 extern void set_numabalancing_state(bool enabled);
1728 extern void task_numa_free(struct task_struct *p);
1729 extern bool should_numa_migrate_memory(struct task_struct *p, struct page *page,
1730                                         int src_nid, int dst_cpu);
1731 #else
1732 static inline void task_numa_fault(int last_node, int node, int pages,
1733                                    int flags)
1734 {
1735 }
1736 static inline pid_t task_numa_group_id(struct task_struct *p)
1737 {
1738         return 0;
1739 }
1740 static inline void set_numabalancing_state(bool enabled)
1741 {
1742 }
1743 static inline void task_numa_free(struct task_struct *p)
1744 {
1745 }
1746 static inline bool should_numa_migrate_memory(struct task_struct *p,
1747                                 struct page *page, int src_nid, int dst_cpu)
1748 {
1749         return true;
1750 }
1751 #endif
1752 
1753 static inline struct pid *task_pid(struct task_struct *task)
1754 {
1755         return task->pids[PIDTYPE_PID].pid;
1756 }
1757 
1758 static inline struct pid *task_tgid(struct task_struct *task)
1759 {
1760         return task->group_leader->pids[PIDTYPE_PID].pid;
1761 }
1762 
1763 /*
1764  * Without tasklist or rcu lock it is not safe to dereference
1765  * the result of task_pgrp/task_session even if task == current,
1766  * we can race with another thread doing sys_setsid/sys_setpgid.
1767  */
1768 static inline struct pid *task_pgrp(struct task_struct *task)
1769 {
1770         return task->group_leader->pids[PIDTYPE_PGID].pid;
1771 }
1772 
1773 static inline struct pid *task_session(struct task_struct *task)
1774 {
1775         return task->group_leader->pids[PIDTYPE_SID].pid;
1776 }
1777 
1778 struct pid_namespace;
1779 
1780 /*
1781  * the helpers to get the task's different pids as they are seen
1782  * from various namespaces
1783  *
1784  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1785  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1786  *                     current.
1787  * task_xid_nr_ns()  : id seen from the ns specified;
1788  *
1789  * set_task_vxid()   : assigns a virtual id to a task;
1790  *
1791  * see also pid_nr() etc in include/linux/pid.h
1792  */
1793 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
1794                         struct pid_namespace *ns);
1795 
1796 static inline pid_t task_pid_nr(struct task_struct *tsk)
1797 {
1798         return tsk->pid;
1799 }
1800 
1801 static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
1802                                         struct pid_namespace *ns)
1803 {
1804         return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1805 }
1806 
1807 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1808 {
1809         return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1810 }
1811 
1812 
1813 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1814 {
1815         return tsk->tgid;
1816 }
1817 
1818 pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1819 
1820 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1821 {
1822         return pid_vnr(task_tgid(tsk));
1823 }
1824 
1825 
1826 static inline int pid_alive(const struct task_struct *p);
1827 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1828 {
1829         pid_t pid = 0;
1830 
1831         rcu_read_lock();
1832         if (pid_alive(tsk))
1833                 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1834         rcu_read_unlock();
1835 
1836         return pid;
1837 }
1838 
1839 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1840 {
1841         return task_ppid_nr_ns(tsk, &init_pid_ns);
1842 }
1843 
1844 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
1845                                         struct pid_namespace *ns)
1846 {
1847         return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1848 }
1849 
1850 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1851 {
1852         return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1853 }
1854 
1855 
1856 static inline pid_t task_session_nr_ns(struct task_struct *tsk,
1857                                         struct pid_namespace *ns)
1858 {
1859         return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1860 }
1861 
1862 static inline pid_t task_session_vnr(struct task_struct *tsk)
1863 {
1864         return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1865 }
1866 
1867 /* obsolete, do not use */
1868 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1869 {
1870         return task_pgrp_nr_ns(tsk, &init_pid_ns);
1871 }
1872 
1873 /**
1874  * pid_alive - check that a task structure is not stale
1875  * @p: Task structure to be checked.
1876  *
1877  * Test if a process is not yet dead (at most zombie state)
1878  * If pid_alive fails, then pointers within the task structure
1879  * can be stale and must not be dereferenced.
1880  *
1881  * Return: 1 if the process is alive. 0 otherwise.
1882  */
1883 static inline int pid_alive(const struct task_struct *p)
1884 {
1885         return p->pids[PIDTYPE_PID].pid != NULL;
1886 }
1887 
1888 /**
1889  * is_global_init - check if a task structure is init
1890  * @tsk: Task structure to be checked.
1891  *
1892  * Check if a task structure is the first user space task the kernel created.
1893  *
1894  * Return: 1 if the task structure is init. 0 otherwise.
1895  */
1896 static inline int is_global_init(struct task_struct *tsk)
1897 {
1898         return tsk->pid == 1;
1899 }
1900 
1901 extern struct pid *cad_pid;
1902 
1903 extern void free_task(struct task_struct *tsk);
1904 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
1905 
1906 extern void __put_task_struct(struct task_struct *t);
1907 
1908 static inline void put_task_struct(struct task_struct *t)
1909 {
1910         if (atomic_dec_and_test(&t->usage))
1911                 __put_task_struct(t);
1912 }
1913 
1914 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1915 extern void task_cputime(struct task_struct *t,
1916                          cputime_t *utime, cputime_t *stime);
1917 extern void task_cputime_scaled(struct task_struct *t,
1918                                 cputime_t *utimescaled, cputime_t *stimescaled);
1919 extern cputime_t task_gtime(struct task_struct *t);
1920 #else
1921 static inline void task_cputime(struct task_struct *t,
1922                                 cputime_t *utime, cputime_t *stime)
1923 {
1924         if (utime)
1925                 *utime = t->utime;
1926         if (stime)
1927                 *stime = t->stime;
1928 }
1929 
1930 static inline void task_cputime_scaled(struct task_struct *t,
1931                                        cputime_t *utimescaled,
1932                                        cputime_t *stimescaled)
1933 {
1934         if (utimescaled)
1935                 *utimescaled = t->utimescaled;
1936         if (stimescaled)
1937                 *stimescaled = t->stimescaled;
1938 }
1939 
1940 static inline cputime_t task_gtime(struct task_struct *t)
1941 {
1942         return t->gtime;
1943 }
1944 #endif
1945 extern void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
1946 extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
1947 
1948 /*
1949  * Per process flags
1950  */
1951 #define PF_EXITING      0x00000004      /* getting shut down */
1952 #define PF_EXITPIDONE   0x00000008      /* pi exit done on shut down */
1953 #define PF_VCPU         0x00000010      /* I'm a virtual CPU */
1954 #define PF_WQ_WORKER    0x00000020      /* I'm a workqueue worker */
1955 #define PF_FORKNOEXEC   0x00000040      /* forked but didn't exec */
1956 #define PF_MCE_PROCESS  0x00000080      /* process policy on mce errors */
1957 #define PF_SUPERPRIV    0x00000100      /* used super-user privileges */
1958 #define PF_DUMPCORE     0x00000200      /* dumped core */
1959 #define PF_SIGNALED     0x00000400      /* killed by a signal */
1960 #define PF_MEMALLOC     0x00000800      /* Allocating memory */
1961 #define PF_NPROC_EXCEEDED 0x00001000    /* set_user noticed that RLIMIT_NPROC was exceeded */
1962 #define PF_USED_MATH    0x00002000      /* if unset the fpu must be initialized before use */
1963 #define PF_USED_ASYNC   0x00004000      /* used async_schedule*(), used by module init */
1964 #define PF_NOFREEZE     0x00008000      /* this thread should not be frozen */
1965 #define PF_FROZEN       0x00010000      /* frozen for system suspend */
1966 #define PF_FSTRANS      0x00020000      /* inside a filesystem transaction */
1967 #define PF_KSWAPD       0x00040000      /* I am kswapd */
1968 #define PF_MEMALLOC_NOIO 0x00080000     /* Allocating memory without IO involved */
1969 #define PF_LESS_THROTTLE 0x00100000     /* Throttle me less: I clean memory */
1970 #define PF_KTHREAD      0x00200000      /* I am a kernel thread */
1971 #define PF_RANDOMIZE    0x00400000      /* randomize virtual address space */
1972 #define PF_SWAPWRITE    0x00800000      /* Allowed to write to swap */
1973 #define PF_NO_SETAFFINITY 0x04000000    /* Userland is not allowed to meddle with cpus_allowed */
1974 #define PF_MCE_EARLY    0x08000000      /* Early kill for mce process policy */
1975 #define PF_MUTEX_TESTER 0x20000000      /* Thread belongs to the rt mutex tester */
1976 #define PF_FREEZER_SKIP 0x40000000      /* Freezer should not count it as freezable */
1977 #define PF_SUSPEND_TASK 0x80000000      /* this thread called freeze_processes and should not be frozen */
1978 
1979 /*
1980  * Only the _current_ task can read/write to tsk->flags, but other
1981  * tasks can access tsk->flags in readonly mode for example
1982  * with tsk_used_math (like during threaded core dumping).
1983  * There is however an exception to this rule during ptrace
1984  * or during fork: the ptracer task is allowed to write to the
1985  * child->flags of its traced child (same goes for fork, the parent
1986  * can write to the child->flags), because we're guaranteed the
1987  * child is not running and in turn not changing child->flags
1988  * at the same time the parent does it.
1989  */
1990 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1991 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1992 #define clear_used_math() clear_stopped_child_used_math(current)
1993 #define set_used_math() set_stopped_child_used_math(current)
1994 #define conditional_stopped_child_used_math(condition, child) \
1995         do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1996 #define conditional_used_math(condition) \
1997         conditional_stopped_child_used_math(condition, current)
1998 #define copy_to_stopped_child_used_math(child) \
1999         do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
2000 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
2001 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
2002 #define used_math() tsk_used_math(current)
2003 
2004 /* __GFP_IO isn't allowed if PF_MEMALLOC_NOIO is set in current->flags
2005  * __GFP_FS is also cleared as it implies __GFP_IO.
2006  */
2007 static inline gfp_t memalloc_noio_flags(gfp_t flags)
2008 {
2009         if (unlikely(current->flags & PF_MEMALLOC_NOIO))
2010                 flags &= ~(__GFP_IO | __GFP_FS);
2011         return flags;
2012 }
2013 
2014 static inline unsigned int memalloc_noio_save(void)
2015 {
2016         unsigned int flags = current->flags & PF_MEMALLOC_NOIO;
2017         current->flags |= PF_MEMALLOC_NOIO;
2018         return flags;
2019 }
2020 
2021 static inline void memalloc_noio_restore(unsigned int flags)
2022 {
2023         current->flags = (current->flags & ~PF_MEMALLOC_NOIO) | flags;
2024 }
2025 
2026 /* Per-process atomic flags. */
2027 #define PFA_NO_NEW_PRIVS 0      /* May not gain new privileges. */
2028 #define PFA_SPREAD_PAGE  1      /* Spread page cache over cpuset */
2029 #define PFA_SPREAD_SLAB  2      /* Spread some slab caches over cpuset */
2030 
2031 
2032 #define TASK_PFA_TEST(name, func)                                       \
2033         static inline bool task_##func(struct task_struct *p)           \
2034         { return test_bit(PFA_##name, &p->atomic_flags); }
2035 #define TASK_PFA_SET(name, func)                                        \
2036         static inline void task_set_##func(struct task_struct *p)       \
2037         { set_bit(PFA_##name, &p->atomic_flags); }
2038 #define TASK_PFA_CLEAR(name, func)                                      \
2039         static inline void task_clear_##func(struct task_struct *p)     \
2040         { clear_bit(PFA_##name, &p->atomic_flags); }
2041 
2042 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
2043 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
2044 
2045 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
2046 TASK_PFA_SET(SPREAD_PAGE, spread_page)
2047 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
2048 
2049 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
2050 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
2051 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
2052 
2053 /*
2054  * task->jobctl flags
2055  */
2056 #define JOBCTL_STOP_SIGMASK     0xffff  /* signr of the last group stop */
2057 
2058 #define JOBCTL_STOP_DEQUEUED_BIT 16     /* stop signal dequeued */
2059 #define JOBCTL_STOP_PENDING_BIT 17      /* task should stop for group stop */
2060 #define JOBCTL_STOP_CONSUME_BIT 18      /* consume group stop count */
2061 #define JOBCTL_TRAP_STOP_BIT    19      /* trap for STOP */
2062 #define JOBCTL_TRAP_NOTIFY_BIT  20      /* trap for NOTIFY */
2063 #define JOBCTL_TRAPPING_BIT     21      /* switching to TRACED */
2064 #define JOBCTL_LISTENING_BIT    22      /* ptracer is listening for events */
2065 
2066 #define JOBCTL_STOP_DEQUEUED    (1 << JOBCTL_STOP_DEQUEUED_BIT)
2067 #define JOBCTL_STOP_PENDING     (1 << JOBCTL_STOP_PENDING_BIT)
2068 #define JOBCTL_STOP_CONSUME     (1 << JOBCTL_STOP_CONSUME_BIT)
2069 #define JOBCTL_TRAP_STOP        (1 << JOBCTL_TRAP_STOP_BIT)
2070 #define JOBCTL_TRAP_NOTIFY      (1 << JOBCTL_TRAP_NOTIFY_BIT)
2071 #define JOBCTL_TRAPPING         (1 << JOBCTL_TRAPPING_BIT)
2072 #define JOBCTL_LISTENING        (1 << JOBCTL_LISTENING_BIT)
2073 
2074 #define JOBCTL_TRAP_MASK        (JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
2075 #define JOBCTL_PENDING_MASK     (JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)
2076 
2077 extern bool task_set_jobctl_pending(struct task_struct *task,
2078                                     unsigned int mask);
2079 extern void task_clear_jobctl_trapping(struct task_struct *task);
2080 extern void task_clear_jobctl_pending(struct task_struct *task,
2081                                       unsigned int mask);
2082 
2083 static inline void rcu_copy_process(struct task_struct *p)
2084 {
2085 #ifdef CONFIG_PREEMPT_RCU
2086         p->rcu_read_lock_nesting = 0;
2087         p->rcu_read_unlock_special.s = 0;
2088         p->rcu_blocked_node = NULL;
2089         INIT_LIST_HEAD(&p->rcu_node_entry);
2090 #endif /* #ifdef CONFIG_PREEMPT_RCU */
2091 #ifdef CONFIG_TASKS_RCU
2092         p->rcu_tasks_holdout = false;
2093         INIT_LIST_HEAD(&p->rcu_tasks_holdout_list);
2094         p->rcu_tasks_idle_cpu = -1;
2095 #endif /* #ifdef CONFIG_TASKS_RCU */
2096 }
2097 
2098 static inline void tsk_restore_flags(struct task_struct *task,
2099                                 unsigned long orig_flags, unsigned long flags)
2100 {
2101         task->flags &= ~flags;
2102         task->flags |= orig_flags & flags;
2103 }
2104 
2105 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur,
2106                                      const struct cpumask *trial);
2107 extern int task_can_attach(struct task_struct *p,
2108                            const struct cpumask *cs_cpus_allowed);
2109 #ifdef CONFIG_SMP
2110 extern void do_set_cpus_allowed(struct task_struct *p,
2111                                const struct cpumask *new_mask);
2112 
2113 extern int set_cpus_allowed_ptr(struct task_struct *p,
2114                                 const struct cpumask *new_mask);
2115 #else
2116 static inline void do_set_cpus_allowed(struct task_struct *p,
2117                                       const struct cpumask *new_mask)
2118 {
2119 }
2120 static inline int set_cpus_allowed_ptr(struct task_struct *p,
2121                                        const struct cpumask *new_mask)
2122 {
2123         if (!cpumask_test_cpu(0, new_mask))
2124                 return -EINVAL;
2125         return 0;
2126 }
2127 #endif
2128 
2129 #ifdef CONFIG_NO_HZ_COMMON
2130 void calc_load_enter_idle(void);
2131 void calc_load_exit_idle(void);
2132 #else
2133 static inline void calc_load_enter_idle(void) { }
2134 static inline void calc_load_exit_idle(void) { }
2135 #endif /* CONFIG_NO_HZ_COMMON */
2136 
2137 #ifndef CONFIG_CPUMASK_OFFSTACK
2138 static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
2139 {
2140         return set_cpus_allowed_ptr(p, &new_mask);
2141 }
2142 #endif
2143 
2144 /*
2145  * Do not use outside of architecture code which knows its limitations.
2146  *
2147  * sched_clock() has no promise of monotonicity or bounded drift between
2148  * CPUs, use (which you should not) requires disabling IRQs.
2149  *
2150  * Please use one of the three interfaces below.
2151  */
2152 extern unsigned long long notrace sched_clock(void);
2153 /*
2154  * See the comment in kernel/sched/clock.c
2155  */
2156 extern u64 cpu_clock(int cpu);
2157 extern u64 local_clock(void);
2158 extern u64 running_clock(void);
2159 extern u64 sched_clock_cpu(int cpu);
2160 
2161 
2162 extern void sched_clock_init(void);
2163 
2164 #ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
2165 static inline void sched_clock_tick(void)
2166 {
2167 }
2168 
2169 static inline void sched_clock_idle_sleep_event(void)
2170 {
2171 }
2172 
2173 static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
2174 {
2175 }
2176 #else
2177 /*
2178  * Architectures can set this to 1 if they have specified
2179  * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
2180  * but then during bootup it turns out that sched_clock()
2181  * is reliable after all:
2182  */
2183 extern int sched_clock_stable(void);
2184 extern void set_sched_clock_stable(void);
2185 extern void clear_sched_clock_stable(void);
2186 
2187 extern void sched_clock_tick(void);
2188 extern void sched_clock_idle_sleep_event(void);
2189 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2190 #endif
2191 
2192 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
2193 /*
2194  * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
2195  * The reason for this explicit opt-in is not to have perf penalty with
2196  * slow sched_clocks.
2197  */
2198 extern void enable_sched_clock_irqtime(void);
2199 extern void disable_sched_clock_irqtime(void);
2200 #else
2201 static inline void enable_sched_clock_irqtime(void) {}
2202 static inline void disable_sched_clock_irqtime(void) {}
2203 #endif
2204 
2205 extern unsigned long long
2206 task_sched_runtime(struct task_struct *task);
2207 
2208 /* sched_exec is called by processes performing an exec */
2209 #ifdef CONFIG_SMP
2210 extern void sched_exec(void);
2211 #else
2212 #define sched_exec()   {}
2213 #endif
2214 
2215 extern void sched_clock_idle_sleep_event(void);
2216 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2217 
2218 #ifdef CONFIG_HOTPLUG_CPU
2219 extern void idle_task_exit(void);
2220 #else
2221 static inline void idle_task_exit(void) {}
2222 #endif
2223 
2224 #if defined(CONFIG_NO_HZ_COMMON) && defined(CONFIG_SMP)
2225 extern void wake_up_nohz_cpu(int cpu);
2226 #else
2227 static inline void wake_up_nohz_cpu(int cpu) { }
2228 #endif
2229 
2230 #ifdef CONFIG_NO_HZ_FULL
2231 extern bool sched_can_stop_tick(void);
2232 extern u64 scheduler_tick_max_deferment(void);
2233 #else
2234 static inline bool sched_can_stop_tick(void) { return false; }
2235 #endif
2236 
2237 #ifdef CONFIG_SCHED_AUTOGROUP
2238 extern void sched_autogroup_create_attach(struct task_struct *p);
2239 extern void sched_autogroup_detach(struct task_struct *p);
2240 extern void sched_autogroup_fork(struct signal_struct *sig);
2241 extern void sched_autogroup_exit(struct signal_struct *sig);
2242 #ifdef CONFIG_PROC_FS
2243 extern void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m);
2244 extern int proc_sched_autogroup_set_nice(struct task_struct *p, int nice);
2245 #endif
2246 #else
2247 static inline void sched_autogroup_create_attach(struct task_struct *p) { }
2248 static inline void sched_autogroup_detach(struct task_struct *p) { }
2249 static inline void sched_autogroup_fork(struct signal_struct *sig) { }
2250 static inline void sched_autogroup_exit(struct signal_struct *sig) { }
2251 #endif
2252 
2253 extern int yield_to(struct task_struct *p, bool preempt);
2254 extern void set_user_nice(struct task_struct *p, long nice);
2255 extern int task_prio(const struct task_struct *p);
2256 /**
2257  * task_nice - return the nice value of a given task.
2258  * @p: the task in question.
2259  *
2260  * Return: The nice value [ -20 ... 0 ... 19 ].
2261  */
2262 static inline int task_nice(const struct task_struct *p)
2263 {
2264         return PRIO_TO_NICE((p)->static_prio);
2265 }
2266 extern int can_nice(const struct task_struct *p, const int nice);
2267 extern int task_curr(const struct task_struct *p);
2268 extern int idle_cpu(int cpu);
2269 extern int sched_setscheduler(struct task_struct *, int,
2270                               const struct sched_param *);
2271 extern int sched_setscheduler_nocheck(struct task_struct *, int,
2272                                       const struct sched_param *);
2273 extern int sched_setattr(struct task_struct *,
2274                          const struct sched_attr *);
2275 extern struct task_struct *idle_task(int cpu);
2276 /**
2277  * is_idle_task - is the specified task an idle task?
2278  * @p: the task in question.
2279  *
2280  * Return: 1 if @p is an idle task. 0 otherwise.
2281  */
2282 static inline bool is_idle_task(const struct task_struct *p)
2283 {
2284         return p->pid == 0;
2285 }
2286 extern struct task_struct *curr_task(int cpu);
2287 extern void set_curr_task(int cpu, struct task_struct *p);
2288 
2289 void yield(void);
2290 
2291 /*
2292  * The default (Linux) execution domain.
2293  */
2294 extern struct exec_domain       default_exec_domain;
2295 
2296 union thread_union {
2297         struct thread_info thread_info;
2298         unsigned long stack[THREAD_SIZE/sizeof(long)];
2299 };
2300 
2301 #ifndef __HAVE_ARCH_KSTACK_END
2302 static inline int kstack_end(void *addr)
2303 {
2304         /* Reliable end of stack detection:
2305          * Some APM bios versions misalign the stack
2306          */
2307         return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
2308 }
2309 #endif
2310 
2311 extern union thread_union init_thread_union;
2312 extern struct task_struct init_task;
2313 
2314 extern struct   mm_struct init_mm;
2315 
2316 extern struct pid_namespace init_pid_ns;
2317 
2318 /*
2319  * find a task by one of its numerical ids
2320  *
2321  * find_task_by_pid_ns():
2322  *      finds a task by its pid in the specified namespace
2323  * find_task_by_vpid():
2324  *      finds a task by its virtual pid
2325  *
2326  * see also find_vpid() etc in include/linux/pid.h
2327  */
2328 
2329 extern struct task_struct *find_task_by_vpid(pid_t nr);
2330 extern struct task_struct *find_task_by_pid_ns(pid_t nr,
2331                 struct pid_namespace *ns);
2332 
2333 /* per-UID process charging. */
2334 extern struct user_struct * alloc_uid(kuid_t);
2335 static inline struct user_struct *get_uid(struct user_struct *u)
2336 {
2337         atomic_inc(&u->__count);
2338         return u;
2339 }
2340 extern void free_uid(struct user_struct *);
2341 
2342 #include <asm/current.h>
2343 
2344 extern void xtime_update(unsigned long ticks);
2345 
2346 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2347 extern int wake_up_process(struct task_struct *tsk);
2348 extern void wake_up_new_task(struct task_struct *tsk);
2349 #ifdef CONFIG_SMP
2350  extern void kick_process(struct task_struct *tsk);
2351 #else
2352  static inline void kick_process(struct task_struct *tsk) { }
2353 #endif
2354 extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
2355 extern void sched_dead(struct task_struct *p);
2356 
2357 extern void proc_caches_init(void);
2358 extern void flush_signals(struct task_struct *);
2359 extern void __flush_signals(struct task_struct *);
2360 extern void ignore_signals(struct task_struct *);
2361 extern void flush_signal_handlers(struct task_struct *, int force_default);
2362 extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
2363 
2364 static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
2365 {
2366         unsigned long flags;
2367         int ret;
2368 
2369         spin_lock_irqsave(&tsk->sighand->siglock, flags);
2370         ret = dequeue_signal(tsk, mask, info);
2371         spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
2372 
2373         return ret;
2374 }
2375 
2376 extern void block_all_signals(int (*notifier)(void *priv), void *priv,
2377                               sigset_t *mask);
2378 extern void unblock_all_signals(void);
2379 extern void release_task(struct task_struct * p);
2380 extern int send_sig_info(int, struct siginfo *, struct task_struct *);
2381 extern int force_sigsegv(int, struct task_struct *);
2382 extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2383 extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
2384 extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2385 extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *,
2386                                 const struct cred *, u32);
2387 extern int kill_pgrp(struct pid *pid, int sig, int priv);
2388 extern int kill_pid(struct pid *pid, int sig, int priv);
2389 extern int kill_proc_info(int, struct siginfo *, pid_t);
2390 extern __must_check bool do_notify_parent(struct task_struct *, int);
2391 extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
2392 extern void force_sig(int, struct task_struct *);
2393 extern int send_sig(int, struct task_struct *, int);
2394 extern int zap_other_threads(struct task_struct *p);
2395 extern struct sigqueue *sigqueue_alloc(void);
2396 extern void sigqueue_free(struct sigqueue *);
2397 extern int send_sigqueue(struct sigqueue *,  struct task_struct *, int group);
2398 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
2399 
2400 static inline void restore_saved_sigmask(void)
2401 {
2402         if (test_and_clear_restore_sigmask())
2403                 __set_current_blocked(&current->saved_sigmask);
2404 }
2405 
2406 static inline sigset_t *sigmask_to_save(void)
2407 {
2408         sigset_t *res = &current->blocked;
2409         if (unlikely(test_restore_sigmask()))
2410                 res = &current->saved_sigmask;
2411         return res;
2412 }
2413 
2414 static inline int kill_cad_pid(int sig, int priv)
2415 {
2416         return kill_pid(cad_pid, sig, priv);
2417 }
2418 
2419 /* These can be the second arg to send_sig_info/send_group_sig_info.  */
2420 #define SEND_SIG_NOINFO ((struct siginfo *) 0)
2421 #define SEND_SIG_PRIV   ((struct siginfo *) 1)
2422 #define SEND_SIG_FORCED ((struct siginfo *) 2)
2423 
2424 /*
2425  * True if we are on the alternate signal stack.
2426  */
2427 static inline int on_sig_stack(unsigned long sp)
2428 {
2429 #ifdef CONFIG_STACK_GROWSUP
2430         return sp >= current->sas_ss_sp &&
2431                 sp - current->sas_ss_sp < current->sas_ss_size;
2432 #else
2433         return sp > current->sas_ss_sp &&
2434                 sp - current->sas_ss_sp <= current->sas_ss_size;
2435 #endif
2436 }
2437 
2438 static inline int sas_ss_flags(unsigned long sp)
2439 {
2440         if (!current->sas_ss_size)
2441                 return SS_DISABLE;
2442 
2443         return on_sig_stack(sp) ? SS_ONSTACK : 0;
2444 }
2445 
2446 static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig)
2447 {
2448         if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))
2449 #ifdef CONFIG_STACK_GROWSUP
2450                 return current->sas_ss_sp;
2451 #else
2452                 return current->sas_ss_sp + current->sas_ss_size;
2453 #endif
2454         return sp;
2455 }
2456 
2457 /*
2458  * Routines for handling mm_structs
2459  */
2460 extern struct mm_struct * mm_alloc(void);
2461 
2462 /* mmdrop drops the mm and the page tables */
2463 extern void __mmdrop(struct mm_struct *);
2464 static inline void mmdrop(struct mm_struct * mm)
2465 {
2466         if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2467                 __mmdrop(mm);
2468 }
2469 
2470 /* mmput gets rid of the mappings and all user-space */
2471 extern void mmput(struct mm_struct *);
2472 /* Grab a reference to a task's mm, if it is not already going away */
2473 extern struct mm_struct *get_task_mm(struct task_struct *task);
2474 /*
2475  * Grab a reference to a task's mm, if it is not already going away
2476  * and ptrace_may_access with the mode parameter passed to it
2477  * succeeds.
2478  */
2479 extern struct mm_struct *mm_access(struct task_struct *task, unsigned int mode);
2480 /* Remove the current tasks stale references to the old mm_struct */
2481 extern void mm_release(struct task_struct *, struct mm_struct *);
2482 
2483 extern int copy_thread(unsigned long, unsigned long, unsigned long,
2484                         struct task_struct *);
2485 extern void flush_thread(void);
2486 extern void exit_thread(void);
2487 
2488 extern void exit_files(struct task_struct *);
2489 extern void __cleanup_sighand(struct sighand_struct *);
2490 
2491 extern void exit_itimers(struct signal_struct *);
2492 extern void flush_itimer_signals(void);
2493 
2494 extern void do_group_exit(int);
2495 
2496 extern int do_execve(struct filename *,
2497                      const char __user * const __user *,
2498                      const char __user * const __user *);
2499 extern int do_execveat(int, struct filename *,
2500                        const char __user * const __user *,
2501                        const char __user * const __user *,
2502                        int);
2503 extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
2504 struct task_struct *fork_idle(int);
2505 extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
2506 
2507 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
2508 static inline void set_task_comm(struct task_struct *tsk, const char *from)
2509 {
2510         __set_task_comm(tsk, from, false);
2511 }
2512 extern char *get_task_comm(char *to, struct task_struct *tsk);
2513 
2514 #ifdef CONFIG_SMP
2515 void scheduler_ipi(void);
2516 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
2517 #else
2518 static inline void scheduler_ipi(void) { }
2519 static inline unsigned long wait_task_inactive(struct task_struct *p,
2520                                                long match_state)
2521 {
2522         return 1;
2523 }
2524 #endif
2525 
2526 #define next_task(p) \
2527         list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
2528 
2529 #define for_each_process(p) \
2530         for (p = &init_task ; (p = next_task(p)) != &init_task ; )
2531 
2532 extern bool current_is_single_threaded(void);
2533 
2534 /*
2535  * Careful: do_each_thread/while_each_thread is a double loop so
2536  *          'break' will not work as expected - use goto instead.
2537  */
2538 #define do_each_thread(g, t) \
2539         for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
2540 
2541 #define while_each_thread(g, t) \
2542         while ((t = next_thread(t)) != g)
2543 
2544 #define __for_each_thread(signal, t)    \
2545         list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node)
2546 
2547 #define for_each_thread(p, t)           \
2548         __for_each_thread((p)->signal, t)
2549 
2550 /* Careful: this is a double loop, 'break' won't work as expected. */
2551 #define for_each_process_thread(p, t)   \
2552         for_each_process(p) for_each_thread(p, t)
2553 
2554 static inline int get_nr_threads(struct task_struct *tsk)
2555 {
2556         return tsk->signal->nr_threads;
2557 }
2558 
2559 static inline bool thread_group_leader(struct task_struct *p)
2560 {
2561         return p->exit_signal >= 0;
2562 }
2563 
2564 /* Do to the insanities of de_thread it is possible for a process
2565  * to have the pid of the thread group leader without actually being
2566  * the thread group leader.  For iteration through the pids in proc
2567  * all we care about is that we have a task with the appropriate
2568  * pid, we don't actually care if we have the right task.
2569  */
2570 static inline bool has_group_leader_pid(struct task_struct *p)
2571 {
2572         return task_pid(p) == p->signal->leader_pid;
2573 }
2574 
2575 static inline
2576 bool same_thread_group(struct task_struct *p1, struct task_struct *p2)
2577 {
2578         return p1->signal == p2->signal;
2579 }
2580 
2581 static inline struct task_struct *next_thread(const struct task_struct *p)
2582 {
2583         return list_entry_rcu(p->thread_group.next,
2584                               struct task_struct, thread_group);
2585 }
2586 
2587 static inline int thread_group_empty(struct task_struct *p)
2588 {
2589         return list_empty(&p->thread_group);
2590 }
2591 
2592 #define delay_group_leader(p) \
2593                 (thread_group_leader(p) && !thread_group_empty(p))
2594 
2595 /*
2596  * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
2597  * subscriptions and synchronises with wait4().  Also used in procfs.  Also
2598  * pins the final release of task.io_context.  Also protects ->cpuset and
2599  * ->cgroup.subsys[]. And ->vfork_done.
2600  *
2601  * Nests both inside and outside of read_lock(&tasklist_lock).
2602  * It must not be nested with write_lock_irq(&tasklist_lock),
2603  * neither inside nor outside.
2604  */
2605 static inline void task_lock(struct task_struct *p)
2606 {
2607         spin_lock(&p->alloc_lock);
2608 }
2609 
2610 static inline void task_unlock(struct task_struct *p)
2611 {
2612         spin_unlock(&p->alloc_lock);
2613 }
2614 
2615 extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
2616                                                         unsigned long *flags);
2617 
2618 static inline struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
2619                                                        unsigned long *flags)
2620 {
2621         struct sighand_struct *ret;
2622 
2623         ret = __lock_task_sighand(tsk, flags);
2624         (void)__cond_lock(&tsk->sighand->siglock, ret);
2625         return ret;
2626 }
2627 
2628 static inline void unlock_task_sighand(struct task_struct *tsk,
2629                                                 unsigned long *flags)
2630 {
2631         spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
2632 }
2633 
2634 #ifdef CONFIG_CGROUPS
2635 static inline void threadgroup_change_begin(struct task_struct *tsk)
2636 {
2637         down_read(&tsk->signal->group_rwsem);
2638 }
2639 static inline void threadgroup_change_end(struct task_struct *tsk)
2640 {
2641         up_read(&tsk->signal->group_rwsem);
2642 }
2643 
2644 /**
2645  * threadgroup_lock - lock threadgroup
2646  * @tsk: member task of the threadgroup to lock
2647  *
2648  * Lock the threadgroup @tsk belongs to.  No new task is allowed to enter
2649  * and member tasks aren't allowed to exit (as indicated by PF_EXITING) or
2650  * change ->group_leader/pid.  This is useful for cases where the threadgroup
2651  * needs to stay stable across blockable operations.
2652  *
2653  * fork and exit paths explicitly call threadgroup_change_{begin|end}() for
2654  * synchronization.  While held, no new task will be added to threadgroup
2655  * and no existing live task will have its PF_EXITING set.
2656  *
2657  * de_thread() does threadgroup_change_{begin|end}() when a non-leader
2658  * sub-thread becomes a new leader.
2659  */
2660 static inline void threadgroup_lock(struct task_struct *tsk)
2661 {
2662         down_write(&tsk->signal->group_rwsem);
2663 }
2664 
2665 /**
2666  * threadgroup_unlock - unlock threadgroup
2667  * @tsk: member task of the threadgroup to unlock
2668  *
2669  * Reverse threadgroup_lock().
2670  */
2671 static inline void threadgroup_unlock(struct task_struct *tsk)
2672 {
2673         up_write(&tsk->signal->group_rwsem);
2674 }
2675 #else
2676 static inline void threadgroup_change_begin(struct task_struct *tsk) {}
2677 static inline void threadgroup_change_end(struct task_struct *tsk) {}
2678 static inline void threadgroup_lock(struct task_struct *tsk) {}
2679 static inline void threadgroup_unlock(struct task_struct *tsk) {}
2680 #endif
2681 
2682 #ifndef __HAVE_THREAD_FUNCTIONS
2683 
2684 #define task_thread_info(task)  ((struct thread_info *)(task)->stack)
2685 #define task_stack_page(task)   ((task)->stack)
2686 
2687 static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
2688 {
2689         *task_thread_info(p) = *task_thread_info(org);
2690         task_thread_info(p)->task = p;
2691 }
2692 
2693 /*
2694  * Return the address of the last usable long on the stack.
2695  *
2696  * When the stack grows down, this is just above the thread
2697  * info struct. Going any lower will corrupt the threadinfo.
2698  *
2699  * When the stack grows up, this is the highest address.
2700  * Beyond that position, we corrupt data on the next page.
2701  */
2702 static inline unsigned long *end_of_stack(struct task_struct *p)
2703 {
2704 #ifdef CONFIG_STACK_GROWSUP
2705         return (unsigned long *)((unsigned long)task_thread_info(p) + THREAD_SIZE) - 1;
2706 #else
2707         return (unsigned long *)(task_thread_info(p) + 1);
2708 #endif
2709 }
2710 
2711 #endif
2712 #define task_stack_end_corrupted(task) \
2713                 (*(end_of_stack(task)) != STACK_END_MAGIC)
2714 
2715 static inline int object_is_on_stack(void *obj)
2716 {
2717         void *stack = task_stack_page(current);
2718 
2719         return (obj >= stack) && (obj < (stack + THREAD_SIZE));
2720 }
2721 
2722 extern void thread_info_cache_init(void);
2723 
2724 #ifdef CONFIG_DEBUG_STACK_USAGE
2725 static inline unsigned long stack_not_used(struct task_struct *p)
2726 {
2727         unsigned long *n = end_of_stack(p);
2728 
2729         do {    /* Skip over canary */
2730                 n++;
2731         } while (!*n);
2732 
2733         return (unsigned long)n - (unsigned long)end_of_stack(p);
2734 }
2735 #endif
2736 extern void set_task_stack_end_magic(struct task_struct *tsk);
2737 
2738 /* set thread flags in other task's structures
2739  * - see asm/thread_info.h for TIF_xxxx flags available
2740  */
2741 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2742 {
2743         set_ti_thread_flag(task_thread_info(tsk), flag);
2744 }
2745 
2746 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2747 {
2748         clear_ti_thread_flag(task_thread_info(tsk), flag);
2749 }
2750 
2751 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2752 {
2753         return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2754 }
2755 
2756 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2757 {
2758         return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2759 }
2760 
2761 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2762 {
2763         return test_ti_thread_flag(task_thread_info(tsk), flag);
2764 }
2765 
2766 static inline void set_tsk_need_resched(struct task_struct *tsk)
2767 {
2768         set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2769 }
2770 
2771 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2772 {
2773         clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2774 }
2775 
2776 static inline int test_tsk_need_resched(struct task_struct *tsk)
2777 {
2778         return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2779 }
2780 
2781 static inline int restart_syscall(void)
2782 {
2783         set_tsk_thread_flag(current, TIF_SIGPENDING);
2784         return -ERESTARTNOINTR;
2785 }
2786 
2787 static inline int signal_pending(struct task_struct *p)
2788 {
2789         return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
2790 }
2791 
2792 static inline int __fatal_signal_pending(struct task_struct *p)
2793 {
2794         return unlikely(sigismember(&p->pending.signal, SIGKILL));
2795 }
2796 
2797 static inline int fatal_signal_pending(struct task_struct *p)
2798 {
2799         return signal_pending(p) && __fatal_signal_pending(p);
2800 }
2801 
2802 static inline int signal_pending_state(long state, struct task_struct *p)
2803 {
2804         if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
2805                 return 0;
2806         if (!signal_pending(p))
2807                 return 0;
2808 
2809         return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
2810 }
2811 
2812 /*
2813  * cond_resched() and cond_resched_lock(): latency reduction via
2814  * explicit rescheduling in places that are safe. The return
2815  * value indicates whether a reschedule was done in fact.
2816  * cond_resched_lock() will drop the spinlock before scheduling,
2817  * cond_resched_softirq() will enable bhs before scheduling.
2818  */
2819 extern int _cond_resched(void);
2820 
2821 #define cond_resched() ({                       \
2822         ___might_sleep(__FILE__, __LINE__, 0);  \
2823         _cond_resched();                        \
2824 })
2825 
2826 extern int __cond_resched_lock(spinlock_t *lock);
2827 
2828 #ifdef CONFIG_PREEMPT_COUNT
2829 #define PREEMPT_LOCK_OFFSET     PREEMPT_OFFSET
2830 #else
2831 #define PREEMPT_LOCK_OFFSET     0
2832 #endif
2833 
2834 #define cond_resched_lock(lock) ({                              \
2835         ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
2836         __cond_resched_lock(lock);                              \
2837 })
2838 
2839 extern int __cond_resched_softirq(void);
2840 
2841 #define cond_resched_softirq() ({                                       \
2842         ___might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET);     \
2843         __cond_resched_softirq();                                       \
2844 })
2845 
2846 static inline void cond_resched_rcu(void)
2847 {
2848 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
2849         rcu_read_unlock();
2850         cond_resched();
2851         rcu_read_lock();
2852 #endif
2853 }
2854 
2855 /*
2856  * Does a critical section need to be broken due to another
2857  * task waiting?: (technically does not depend on CONFIG_PREEMPT,
2858  * but a general need for low latency)
2859  */
2860 static inline int spin_needbreak(spinlock_t *lock)
2861 {
2862 #ifdef CONFIG_PREEMPT
2863         return spin_is_contended(lock);
2864 #else
2865         return 0;
2866 #endif
2867 }
2868 
2869 /*
2870  * Idle thread specific functions to determine the need_resched
2871  * polling state.
2872  */
2873 #ifdef TIF_POLLING_NRFLAG
2874 static inline int tsk_is_polling(struct task_struct *p)
2875 {
2876         return test_tsk_thread_flag(p, TIF_POLLING_NRFLAG);
2877 }
2878 
2879 static inline void __current_set_polling(void)
2880 {
2881         set_thread_flag(TIF_POLLING_NRFLAG);
2882 }
2883 
2884 static inline bool __must_check current_set_polling_and_test(void)
2885 {
2886         __current_set_polling();
2887 
2888         /*
2889          * Polling state must be visible before we test NEED_RESCHED,
2890          * paired by resched_curr()
2891          */
2892         smp_mb__after_atomic();
2893 
2894         return unlikely(tif_need_resched());
2895 }
2896 
2897 static inline void __current_clr_polling(void)
2898 {
2899         clear_thread_flag(TIF_POLLING_NRFLAG);
2900 }
2901 
2902 static inline bool __must_check current_clr_polling_and_test(void)
2903 {
2904         __current_clr_polling();
2905 
2906         /*
2907          * Polling state must be visible before we test NEED_RESCHED,
2908          * paired by resched_curr()
2909          */
2910         smp_mb__after_atomic();
2911 
2912         return unlikely(tif_need_resched());
2913 }
2914 
2915 #else
2916 static inline int tsk_is_polling(struct task_struct *p) { return 0; }
2917 static inline void __current_set_polling(void) { }
2918 static inline void __current_clr_polling(void) { }
2919 
2920 static inline bool __must_check current_set_polling_and_test(void)
2921 {
2922         return unlikely(tif_need_resched());
2923 }
2924 static inline bool __must_check current_clr_polling_and_test(void)
2925 {
2926         return unlikely(tif_need_resched());
2927 }
2928 #endif
2929 
2930 static inline void current_clr_polling(void)
2931 {
2932         __current_clr_polling();
2933 
2934         /*
2935          * Ensure we check TIF_NEED_RESCHED after we clear the polling bit.
2936          * Once the bit is cleared, we'll get IPIs with every new
2937          * TIF_NEED_RESCHED and the IPI handler, scheduler_ipi(), will also
2938          * fold.
2939          */
2940         smp_mb(); /* paired with resched_curr() */
2941 
2942         preempt_fold_need_resched();
2943 }
2944 
2945 static __always_inline bool need_resched(void)
2946 {
2947         return unlikely(tif_need_resched());
2948 }
2949 
2950 /*
2951  * Thread group CPU time accounting.
2952  */
2953 void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
2954 void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
2955 
2956 static inline void thread_group_cputime_init(struct signal_struct *sig)
2957 {
2958         raw_spin_lock_init(&sig->cputimer.lock);
2959 }
2960 
2961 /*
2962  * Reevaluate whether the task has signals pending delivery.
2963  * Wake the task if so.
2964  * This is required every time the blocked sigset_t changes.
2965  * callers must hold sighand->siglock.
2966  */
2967 extern void recalc_sigpending_and_wake(struct task_struct *t);
2968 extern void recalc_sigpending(void);
2969 
2970 extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
2971 
2972 static inline void signal_wake_up(struct task_struct *t, bool resume)
2973 {
2974         signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0);
2975 }
2976 static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
2977 {
2978         signal_wake_up_state(t, resume ? __TASK_TRACED : 0);
2979 }
2980 
2981 /*
2982  * Wrappers for p->thread_info->cpu access. No-op on UP.
2983  */
2984 #ifdef CONFIG_SMP
2985 
2986 static inline unsigned int task_cpu(const struct task_struct *p)
2987 {
2988         return task_thread_info(p)->cpu;
2989 }
2990 
2991 static inline int task_node(const struct task_struct *p)
2992 {
2993         return cpu_to_node(task_cpu(p));
2994 }
2995 
2996 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2997 
2998 #else
2999 
3000 static inline unsigned int task_cpu(const struct task_struct *p)
3001 {
3002         return 0;
3003 }
3004 
3005 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
3006 {
3007 }
3008 
3009 #endif /* CONFIG_SMP */
3010 
3011 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
3012 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
3013 
3014 #ifdef CONFIG_CGROUP_SCHED
3015 extern struct task_group root_task_group;
3016 #endif /* CONFIG_CGROUP_SCHED */
3017 
3018 extern int task_can_switch_user(struct user_struct *up,
3019                                         struct task_struct *tsk);
3020 
3021 #ifdef CONFIG_TASK_XACCT
3022 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
3023 {
3024         tsk->ioac.rchar += amt;
3025 }
3026 
3027 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
3028 {
3029         tsk->ioac.wchar += amt;
3030 }
3031 
3032 static inline void inc_syscr(struct task_struct *tsk)
3033 {
3034         tsk->ioac.syscr++;
3035 }
3036 
3037 static inline void inc_syscw(struct task_struct *tsk)
3038 {
3039         tsk->ioac.syscw++;
3040 }
3041 #else
3042 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
3043 {
3044 }
3045 
3046 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
3047 {
3048 }
3049 
3050 static inline void inc_syscr(struct task_struct *tsk)
3051 {
3052 }
3053 
3054 static inline void inc_syscw(struct task_struct *tsk)
3055 {
3056 }
3057 #endif
3058 
3059 #ifndef TASK_SIZE_OF
3060 #define TASK_SIZE_OF(tsk)       TASK_SIZE
3061 #endif
3062 
3063 #ifdef CONFIG_MEMCG
3064 extern void mm_update_next_owner(struct mm_struct *mm);
3065 #else
3066 static inline void mm_update_next_owner(struct mm_struct *mm)
3067 {
3068 }
3069 #endif /* CONFIG_MEMCG */
3070 
3071 static inline unsigned long task_rlimit(const struct task_struct *tsk,
3072                 unsigned int limit)
3073 {
3074         return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_cur);
3075 }
3076 
3077 static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
3078                 unsigned int limit)
3079 {
3080         return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_max);
3081 }
3082 
3083 static inline unsigned long rlimit(unsigned int limit)
3084 {
3085         return task_rlimit(current, limit);
3086 }
3087 
3088 static inline unsigned long rlimit_max(unsigned int limit)
3089 {
3090         return task_rlimit_max(current, limit);
3091 }
3092 
3093 #endif
3094 

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