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

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