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

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