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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/signal.h>
 37 #include <linux/compiler.h>
 38 #include <linux/completion.h>
 39 #include <linux/pid.h>
 40 #include <linux/percpu.h>
 41 #include <linux/topology.h>
 42 #include <linux/proportions.h>
 43 #include <linux/seccomp.h>
 44 #include <linux/rcupdate.h>
 45 #include <linux/rculist.h>
 46 #include <linux/rtmutex.h>
 47 
 48 #include <linux/time.h>
 49 #include <linux/param.h>
 50 #include <linux/resource.h>
 51 #include <linux/timer.h>
 52 #include <linux/hrtimer.h>
 53 #include <linux/task_io_accounting.h>
 54 #include <linux/latencytop.h>
 55 #include <linux/cred.h>
 56 #include <linux/llist.h>
 57 #include <linux/uidgid.h>
 58 #include <linux/gfp.h>
 59 
 60 #include <asm/processor.h>
 61 
 62 #define SCHED_ATTR_SIZE_VER0    48      /* sizeof first published struct */
 63 
 64 /*
 65  * Extended scheduling parameters data structure.
 66  *
 67  * This is needed because the original struct sched_param can not be
 68  * altered without introducing ABI issues with legacy applications
 69  * (e.g., in sched_getparam()).
 70  *
 71  * However, the possibility of specifying more than just a priority for
 72  * the tasks may be useful for a wide variety of application fields, e.g.,
 73  * multimedia, streaming, automation and control, and many others.
 74  *
 75  * This variant (sched_attr) is meant at describing a so-called
 76  * sporadic time-constrained task. In such model a task is specified by:
 77  *  - the activation period or minimum instance inter-arrival time;
 78  *  - the maximum (or average, depending on the actual scheduling
 79  *    discipline) computation time of all instances, a.k.a. runtime;
 80  *  - the deadline (relative to the actual activation time) of each
 81  *    instance.
 82  * Very briefly, a periodic (sporadic) task asks for the execution of
 83  * some specific computation --which is typically called an instance--
 84  * (at most) every period. Moreover, each instance typically lasts no more
 85  * than the runtime and must be completed by time instant t equal to
 86  * the instance activation time + the deadline.
 87  *
 88  * This is reflected by the actual fields of the sched_attr structure:
 89  *
 90  *  @size               size of the structure, for fwd/bwd compat.
 91  *
 92  *  @sched_policy       task's scheduling policy
 93  *  @sched_flags        for customizing the scheduler behaviour
 94  *  @sched_nice         task's nice value      (SCHED_NORMAL/BATCH)
 95  *  @sched_priority     task's static priority (SCHED_FIFO/RR)
 96  *  @sched_deadline     representative of the task's deadline
 97  *  @sched_runtime      representative of the task's runtime
 98  *  @sched_period       representative of the task's period
 99  *
100  * Given this task model, there are a multiplicity of scheduling algorithms
101  * and policies, that can be used to ensure all the tasks will make their
102  * timing constraints.
103  *
104  * As of now, the SCHED_DEADLINE policy (sched_dl scheduling class) is the
105  * only user of this new interface. More information about the algorithm
106  * available in the scheduling class file or in Documentation/.
107  */
108 struct sched_attr {
109         u32 size;
110 
111         u32 sched_policy;
112         u64 sched_flags;
113 
114         /* SCHED_NORMAL, SCHED_BATCH */
115         s32 sched_nice;
116 
117         /* SCHED_FIFO, SCHED_RR */
118         u32 sched_priority;
119 
120         /* SCHED_DEADLINE */
121         u64 sched_runtime;
122         u64 sched_deadline;
123         u64 sched_period;
124 };
125 
126 struct exec_domain;
127 struct futex_pi_state;
128 struct robust_list_head;
129 struct bio_list;
130 struct fs_struct;
131 struct perf_event_context;
132 struct blk_plug;
133 struct filename;
134 
135 #define VMACACHE_BITS 2
136 #define VMACACHE_SIZE (1U << VMACACHE_BITS)
137 #define VMACACHE_MASK (VMACACHE_SIZE - 1)
138 
139 /*
140  * These are the constant used to fake the fixed-point load-average
141  * counting. Some notes:
142  *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
143  *    a load-average precision of 10 bits integer + 11 bits fractional
144  *  - if you want to count load-averages more often, you need more
145  *    precision, or rounding will get you. With 2-second counting freq,
146  *    the EXP_n values would be 1981, 2034 and 2043 if still using only
147  *    11 bit fractions.
148  */
149 extern unsigned long avenrun[];         /* Load averages */
150 extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
151 
152 #define FSHIFT          11              /* nr of bits of precision */
153 #define FIXED_1         (1<<FSHIFT)     /* 1.0 as fixed-point */
154 #define LOAD_FREQ       (5*HZ+1)        /* 5 sec intervals */
155 #define EXP_1           1884            /* 1/exp(5sec/1min) as fixed-point */
156 #define EXP_5           2014            /* 1/exp(5sec/5min) */
157 #define EXP_15          2037            /* 1/exp(5sec/15min) */
158 
159 #define CALC_LOAD(load,exp,n) \
160         load *= exp; \
161         load += n*(FIXED_1-exp); \
162         load >>= FSHIFT;
163 
164 extern unsigned long total_forks;
165 extern int nr_threads;
166 DECLARE_PER_CPU(unsigned long, process_counts);
167 extern int nr_processes(void);
168 extern unsigned long nr_running(void);
169 extern unsigned long nr_iowait(void);
170 extern unsigned long nr_iowait_cpu(int cpu);
171 extern unsigned long this_cpu_load(void);
172 
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         struct timespec blkio_start, blkio_end; /* 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         struct timespec freepages_start, freepages_end;
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 #ifdef CONFIG_RCU_BOOST
1274         struct rt_mutex *rcu_boost_mutex;
1275 #endif /* #ifdef CONFIG_RCU_BOOST */
1276 
1277 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
1278         struct sched_info sched_info;
1279 #endif
1280 
1281         struct list_head tasks;
1282 #ifdef CONFIG_SMP
1283         struct plist_node pushable_tasks;
1284         struct rb_node pushable_dl_tasks;
1285 #endif
1286 
1287         struct mm_struct *mm, *active_mm;
1288 #ifdef CONFIG_COMPAT_BRK
1289         unsigned brk_randomized:1;
1290 #endif
1291         /* per-thread vma caching */
1292         u32 vmacache_seqnum;
1293         struct vm_area_struct *vmacache[VMACACHE_SIZE];
1294 #if defined(SPLIT_RSS_COUNTING)
1295         struct task_rss_stat    rss_stat;
1296 #endif
1297 /* task state */
1298         int exit_state;
1299         int exit_code, exit_signal;
1300         int pdeath_signal;  /*  The signal sent when the parent dies  */
1301         unsigned int jobctl;    /* JOBCTL_*, siglock protected */
1302 
1303         /* Used for emulating ABI behavior of previous Linux versions */
1304         unsigned int personality;
1305 
1306         unsigned in_execve:1;   /* Tell the LSMs that the process is doing an
1307                                  * execve */
1308         unsigned in_iowait:1;
1309 
1310         /* task may not gain privileges */
1311         unsigned no_new_privs:1;
1312 
1313         /* Revert to default priority/policy when forking */
1314         unsigned sched_reset_on_fork:1;
1315         unsigned sched_contributes_to_load:1;
1316 
1317         pid_t pid;
1318         pid_t tgid;
1319 
1320 #ifdef CONFIG_CC_STACKPROTECTOR
1321         /* Canary value for the -fstack-protector gcc feature */
1322         unsigned long stack_canary;
1323 #endif
1324         /*
1325          * pointers to (original) parent process, youngest child, younger sibling,
1326          * older sibling, respectively.  (p->father can be replaced with
1327          * p->real_parent->pid)
1328          */
1329         struct task_struct __rcu *real_parent; /* real parent process */
1330         struct task_struct __rcu *parent; /* recipient of SIGCHLD, wait4() reports */
1331         /*
1332          * children/sibling forms the list of my natural children
1333          */
1334         struct list_head children;      /* list of my children */
1335         struct list_head sibling;       /* linkage in my parent's children list */
1336         struct task_struct *group_leader;       /* threadgroup leader */
1337 
1338         /*
1339          * ptraced is the list of tasks this task is using ptrace on.
1340          * This includes both natural children and PTRACE_ATTACH targets.
1341          * p->ptrace_entry is p's link on the p->parent->ptraced list.
1342          */
1343         struct list_head ptraced;
1344         struct list_head ptrace_entry;
1345 
1346         /* PID/PID hash table linkage. */
1347         struct pid_link pids[PIDTYPE_MAX];
1348         struct list_head thread_group;
1349         struct list_head thread_node;
1350 
1351         struct completion *vfork_done;          /* for vfork() */
1352         int __user *set_child_tid;              /* CLONE_CHILD_SETTID */
1353         int __user *clear_child_tid;            /* CLONE_CHILD_CLEARTID */
1354 
1355         cputime_t utime, stime, utimescaled, stimescaled;
1356         cputime_t gtime;
1357 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
1358         struct cputime prev_cputime;
1359 #endif
1360 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1361         seqlock_t vtime_seqlock;
1362         unsigned long long vtime_snap;
1363         enum {
1364                 VTIME_SLEEPING = 0,
1365                 VTIME_USER,
1366                 VTIME_SYS,
1367         } vtime_snap_whence;
1368 #endif
1369         unsigned long nvcsw, nivcsw; /* context switch counts */
1370         struct timespec start_time;             /* monotonic time */
1371         struct timespec real_start_time;        /* boot based time */
1372 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1373         unsigned long min_flt, maj_flt;
1374 
1375         struct task_cputime cputime_expires;
1376         struct list_head cpu_timers[3];
1377 
1378 /* process credentials */
1379         const struct cred __rcu *real_cred; /* objective and real subjective task
1380                                          * credentials (COW) */
1381         const struct cred __rcu *cred;  /* effective (overridable) subjective task
1382                                          * credentials (COW) */
1383         char comm[TASK_COMM_LEN]; /* executable name excluding path
1384                                      - access with [gs]et_task_comm (which lock
1385                                        it with task_lock())
1386                                      - initialized normally by setup_new_exec */
1387 /* file system info */
1388         int link_count, total_link_count;
1389 #ifdef CONFIG_SYSVIPC
1390 /* ipc stuff */
1391         struct sysv_sem sysvsem;
1392 #endif
1393 #ifdef CONFIG_DETECT_HUNG_TASK
1394 /* hung task detection */
1395         unsigned long last_switch_count;
1396 #endif
1397 /* CPU-specific state of this task */
1398         struct thread_struct thread;
1399 /* filesystem information */
1400         struct fs_struct *fs;
1401 /* open file information */
1402         struct files_struct *files;
1403 /* namespaces */
1404         struct nsproxy *nsproxy;
1405 /* signal handlers */
1406         struct signal_struct *signal;
1407         struct sighand_struct *sighand;
1408 
1409         sigset_t blocked, real_blocked;
1410         sigset_t saved_sigmask; /* restored if set_restore_sigmask() was used */
1411         struct sigpending pending;
1412 
1413         unsigned long sas_ss_sp;
1414         size_t sas_ss_size;
1415         int (*notifier)(void *priv);
1416         void *notifier_data;
1417         sigset_t *notifier_mask;
1418         struct callback_head *task_works;
1419 
1420         struct audit_context *audit_context;
1421 #ifdef CONFIG_AUDITSYSCALL
1422         kuid_t loginuid;
1423         unsigned int sessionid;
1424 #endif
1425         struct seccomp seccomp;
1426 
1427 /* Thread group tracking */
1428         u32 parent_exec_id;
1429         u32 self_exec_id;
1430 /* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1431  * mempolicy */
1432         spinlock_t alloc_lock;
1433 
1434         /* Protection of the PI data structures: */
1435         raw_spinlock_t pi_lock;
1436 
1437 #ifdef CONFIG_RT_MUTEXES
1438         /* PI waiters blocked on a rt_mutex held by this task */
1439         struct rb_root pi_waiters;
1440         struct rb_node *pi_waiters_leftmost;
1441         /* Deadlock detection and priority inheritance handling */
1442         struct rt_mutex_waiter *pi_blocked_on;
1443         /* Top pi_waiters task */
1444         struct task_struct *pi_top_task;
1445 #endif
1446 
1447 #ifdef CONFIG_DEBUG_MUTEXES
1448         /* mutex deadlock detection */
1449         struct mutex_waiter *blocked_on;
1450 #endif
1451 #ifdef CONFIG_TRACE_IRQFLAGS
1452         unsigned int irq_events;
1453         unsigned long hardirq_enable_ip;
1454         unsigned long hardirq_disable_ip;
1455         unsigned int hardirq_enable_event;
1456         unsigned int hardirq_disable_event;
1457         int hardirqs_enabled;
1458         int hardirq_context;
1459         unsigned long softirq_disable_ip;
1460         unsigned long softirq_enable_ip;
1461         unsigned int softirq_disable_event;
1462         unsigned int softirq_enable_event;
1463         int softirqs_enabled;
1464         int softirq_context;
1465 #endif
1466 #ifdef CONFIG_LOCKDEP
1467 # define MAX_LOCK_DEPTH 48UL
1468         u64 curr_chain_key;
1469         int lockdep_depth;
1470         unsigned int lockdep_recursion;
1471         struct held_lock held_locks[MAX_LOCK_DEPTH];
1472         gfp_t lockdep_reclaim_gfp;
1473 #endif
1474 
1475 /* journalling filesystem info */
1476         void *journal_info;
1477 
1478 /* stacked block device info */
1479         struct bio_list *bio_list;
1480 
1481 #ifdef CONFIG_BLOCK
1482 /* stack plugging */
1483         struct blk_plug *plug;
1484 #endif
1485 
1486 /* VM state */
1487         struct reclaim_state *reclaim_state;
1488 
1489         struct backing_dev_info *backing_dev_info;
1490 
1491         struct io_context *io_context;
1492 
1493         unsigned long ptrace_message;
1494         siginfo_t *last_siginfo; /* For ptrace use.  */
1495         struct task_io_accounting ioac;
1496 #if defined(CONFIG_TASK_XACCT)
1497         u64 acct_rss_mem1;      /* accumulated rss usage */
1498         u64 acct_vm_mem1;       /* accumulated virtual memory usage */
1499         cputime_t acct_timexpd; /* stime + utime since last update */
1500 #endif
1501 #ifdef CONFIG_CPUSETS
1502         nodemask_t mems_allowed;        /* Protected by alloc_lock */
1503         seqcount_t mems_allowed_seq;    /* Seqence no to catch updates */
1504         int cpuset_mem_spread_rotor;
1505         int cpuset_slab_spread_rotor;
1506 #endif
1507 #ifdef CONFIG_CGROUPS
1508         /* Control Group info protected by css_set_lock */
1509         struct css_set __rcu *cgroups;
1510         /* cg_list protected by css_set_lock and tsk->alloc_lock */
1511         struct list_head cg_list;
1512 #endif
1513 #ifdef CONFIG_FUTEX
1514         struct robust_list_head __user *robust_list;
1515 #ifdef CONFIG_COMPAT
1516         struct compat_robust_list_head __user *compat_robust_list;
1517 #endif
1518         struct list_head pi_state_list;
1519         struct futex_pi_state *pi_state_cache;
1520 #endif
1521 #ifdef CONFIG_PERF_EVENTS
1522         struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1523         struct mutex perf_event_mutex;
1524         struct list_head perf_event_list;
1525 #endif
1526 #ifdef CONFIG_DEBUG_PREEMPT
1527         unsigned long preempt_disable_ip;
1528 #endif
1529 #ifdef CONFIG_NUMA
1530         struct mempolicy *mempolicy;    /* Protected by alloc_lock */
1531         short il_next;
1532         short pref_node_fork;
1533 #endif
1534 #ifdef CONFIG_NUMA_BALANCING
1535         int numa_scan_seq;
1536         unsigned int numa_scan_period;
1537         unsigned int numa_scan_period_max;
1538         int numa_preferred_nid;
1539         unsigned long numa_migrate_retry;
1540         u64 node_stamp;                 /* migration stamp  */
1541         u64 last_task_numa_placement;
1542         u64 last_sum_exec_runtime;
1543         struct callback_head numa_work;
1544 
1545         struct list_head numa_entry;
1546         struct numa_group *numa_group;
1547 
1548         /*
1549          * Exponential decaying average of faults on a per-node basis.
1550          * Scheduling placement decisions are made based on the these counts.
1551          * The values remain static for the duration of a PTE scan
1552          */
1553         unsigned long *numa_faults_memory;
1554         unsigned long total_numa_faults;
1555 
1556         /*
1557          * numa_faults_buffer records faults per node during the current
1558          * scan window. When the scan completes, the counts in
1559          * numa_faults_memory decay and these values are copied.
1560          */
1561         unsigned long *numa_faults_buffer_memory;
1562 
1563         /*
1564          * Track the nodes the process was running on when a NUMA hinting
1565          * fault was incurred.
1566          */
1567         unsigned long *numa_faults_cpu;
1568         unsigned long *numa_faults_buffer_cpu;
1569 
1570         /*
1571          * numa_faults_locality tracks if faults recorded during the last
1572          * scan window were remote/local. The task scan period is adapted
1573          * based on the locality of the faults with different weights
1574          * depending on whether they were shared or private faults
1575          */
1576         unsigned long numa_faults_locality[2];
1577 
1578         unsigned long numa_pages_migrated;
1579 #endif /* CONFIG_NUMA_BALANCING */
1580 
1581         struct rcu_head rcu;
1582 
1583         /*
1584          * cache last used pipe for splice
1585          */
1586         struct pipe_inode_info *splice_pipe;
1587 
1588         struct page_frag task_frag;
1589 
1590 #ifdef  CONFIG_TASK_DELAY_ACCT
1591         struct task_delay_info *delays;
1592 #endif
1593 #ifdef CONFIG_FAULT_INJECTION
1594         int make_it_fail;
1595 #endif
1596         /*
1597          * when (nr_dirtied >= nr_dirtied_pause), it's time to call
1598          * balance_dirty_pages() for some dirty throttling pause
1599          */
1600         int nr_dirtied;
1601         int nr_dirtied_pause;
1602         unsigned long dirty_paused_when; /* start of a write-and-pause period */
1603 
1604 #ifdef CONFIG_LATENCYTOP
1605         int latency_record_count;
1606         struct latency_record latency_record[LT_SAVECOUNT];
1607 #endif
1608         /*
1609          * time slack values; these are used to round up poll() and
1610          * select() etc timeout values. These are in nanoseconds.
1611          */
1612         unsigned long timer_slack_ns;
1613         unsigned long default_timer_slack_ns;
1614 
1615 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1616         /* Index of current stored address in ret_stack */
1617         int curr_ret_stack;
1618         /* Stack of return addresses for return function tracing */
1619         struct ftrace_ret_stack *ret_stack;
1620         /* time stamp for last schedule */
1621         unsigned long long ftrace_timestamp;
1622         /*
1623          * Number of functions that haven't been traced
1624          * because of depth overrun.
1625          */
1626         atomic_t trace_overrun;
1627         /* Pause for the tracing */
1628         atomic_t tracing_graph_pause;
1629 #endif
1630 #ifdef CONFIG_TRACING
1631         /* state flags for use by tracers */
1632         unsigned long trace;
1633         /* bitmask and counter of trace recursion */
1634         unsigned long trace_recursion;
1635 #endif /* CONFIG_TRACING */
1636 #ifdef CONFIG_MEMCG /* memcg uses this to do batch job */
1637         struct memcg_batch_info {
1638                 int do_batch;   /* incremented when batch uncharge started */
1639                 struct mem_cgroup *memcg; /* target memcg of uncharge */
1640                 unsigned long nr_pages; /* uncharged usage */
1641                 unsigned long memsw_nr_pages; /* uncharged mem+swap usage */
1642         } memcg_batch;
1643         unsigned int memcg_kmem_skip_account;
1644         struct memcg_oom_info {
1645                 struct mem_cgroup *memcg;
1646                 gfp_t gfp_mask;
1647                 int order;
1648                 unsigned int may_oom:1;
1649         } memcg_oom;
1650 #endif
1651 #ifdef CONFIG_UPROBES
1652         struct uprobe_task *utask;
1653 #endif
1654 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1655         unsigned int    sequential_io;
1656         unsigned int    sequential_io_avg;
1657 #endif
1658 };
1659 
1660 /* Future-safe accessor for struct task_struct's cpus_allowed. */
1661 #define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
1662 
1663 #define TNF_MIGRATED    0x01
1664 #define TNF_NO_GROUP    0x02
1665 #define TNF_SHARED      0x04
1666 #define TNF_FAULT_LOCAL 0x08
1667 
1668 #ifdef CONFIG_NUMA_BALANCING
1669 extern void task_numa_fault(int last_node, int node, int pages, int flags);
1670 extern pid_t task_numa_group_id(struct task_struct *p);
1671 extern void set_numabalancing_state(bool enabled);
1672 extern void task_numa_free(struct task_struct *p);
1673 extern bool should_numa_migrate_memory(struct task_struct *p, struct page *page,
1674                                         int src_nid, int dst_cpu);
1675 #else
1676 static inline void task_numa_fault(int last_node, int node, int pages,
1677                                    int flags)
1678 {
1679 }
1680 static inline pid_t task_numa_group_id(struct task_struct *p)
1681 {
1682         return 0;
1683 }
1684 static inline void set_numabalancing_state(bool enabled)
1685 {
1686 }
1687 static inline void task_numa_free(struct task_struct *p)
1688 {
1689 }
1690 static inline bool should_numa_migrate_memory(struct task_struct *p,
1691                                 struct page *page, int src_nid, int dst_cpu)
1692 {
1693         return true;
1694 }
1695 #endif
1696 
1697 static inline struct pid *task_pid(struct task_struct *task)
1698 {
1699         return task->pids[PIDTYPE_PID].pid;
1700 }
1701 
1702 static inline struct pid *task_tgid(struct task_struct *task)
1703 {
1704         return task->group_leader->pids[PIDTYPE_PID].pid;
1705 }
1706 
1707 /*
1708  * Without tasklist or rcu lock it is not safe to dereference
1709  * the result of task_pgrp/task_session even if task == current,
1710  * we can race with another thread doing sys_setsid/sys_setpgid.
1711  */
1712 static inline struct pid *task_pgrp(struct task_struct *task)
1713 {
1714         return task->group_leader->pids[PIDTYPE_PGID].pid;
1715 }
1716 
1717 static inline struct pid *task_session(struct task_struct *task)
1718 {
1719         return task->group_leader->pids[PIDTYPE_SID].pid;
1720 }
1721 
1722 struct pid_namespace;
1723 
1724 /*
1725  * the helpers to get the task's different pids as they are seen
1726  * from various namespaces
1727  *
1728  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1729  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1730  *                     current.
1731  * task_xid_nr_ns()  : id seen from the ns specified;
1732  *
1733  * set_task_vxid()   : assigns a virtual id to a task;
1734  *
1735  * see also pid_nr() etc in include/linux/pid.h
1736  */
1737 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
1738                         struct pid_namespace *ns);
1739 
1740 static inline pid_t task_pid_nr(struct task_struct *tsk)
1741 {
1742         return tsk->pid;
1743 }
1744 
1745 static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
1746                                         struct pid_namespace *ns)
1747 {
1748         return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1749 }
1750 
1751 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1752 {
1753         return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1754 }
1755 
1756 
1757 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1758 {
1759         return tsk->tgid;
1760 }
1761 
1762 pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1763 
1764 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1765 {
1766         return pid_vnr(task_tgid(tsk));
1767 }
1768 
1769 
1770 static inline int pid_alive(const struct task_struct *p);
1771 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1772 {
1773         pid_t pid = 0;
1774 
1775         rcu_read_lock();
1776         if (pid_alive(tsk))
1777                 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1778         rcu_read_unlock();
1779 
1780         return pid;
1781 }
1782 
1783 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1784 {
1785         return task_ppid_nr_ns(tsk, &init_pid_ns);
1786 }
1787 
1788 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
1789                                         struct pid_namespace *ns)
1790 {
1791         return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1792 }
1793 
1794 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1795 {
1796         return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1797 }
1798 
1799 
1800 static inline pid_t task_session_nr_ns(struct task_struct *tsk,
1801                                         struct pid_namespace *ns)
1802 {
1803         return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1804 }
1805 
1806 static inline pid_t task_session_vnr(struct task_struct *tsk)
1807 {
1808         return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1809 }
1810 
1811 /* obsolete, do not use */
1812 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1813 {
1814         return task_pgrp_nr_ns(tsk, &init_pid_ns);
1815 }
1816 
1817 /**
1818  * pid_alive - check that a task structure is not stale
1819  * @p: Task structure to be checked.
1820  *
1821  * Test if a process is not yet dead (at most zombie state)
1822  * If pid_alive fails, then pointers within the task structure
1823  * can be stale and must not be dereferenced.
1824  *
1825  * Return: 1 if the process is alive. 0 otherwise.
1826  */
1827 static inline int pid_alive(const struct task_struct *p)
1828 {
1829         return p->pids[PIDTYPE_PID].pid != NULL;
1830 }
1831 
1832 /**
1833  * is_global_init - check if a task structure is init
1834  * @tsk: Task structure to be checked.
1835  *
1836  * Check if a task structure is the first user space task the kernel created.
1837  *
1838  * Return: 1 if the task structure is init. 0 otherwise.
1839  */
1840 static inline int is_global_init(struct task_struct *tsk)
1841 {
1842         return tsk->pid == 1;
1843 }
1844 
1845 extern struct pid *cad_pid;
1846 
1847 extern void free_task(struct task_struct *tsk);
1848 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
1849 
1850 extern void __put_task_struct(struct task_struct *t);
1851 
1852 static inline void put_task_struct(struct task_struct *t)
1853 {
1854         if (atomic_dec_and_test(&t->usage))
1855                 __put_task_struct(t);
1856 }
1857 
1858 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1859 extern void task_cputime(struct task_struct *t,
1860                          cputime_t *utime, cputime_t *stime);
1861 extern void task_cputime_scaled(struct task_struct *t,
1862                                 cputime_t *utimescaled, cputime_t *stimescaled);
1863 extern cputime_t task_gtime(struct task_struct *t);
1864 #else
1865 static inline void task_cputime(struct task_struct *t,
1866                                 cputime_t *utime, cputime_t *stime)
1867 {
1868         if (utime)
1869                 *utime = t->utime;
1870         if (stime)
1871                 *stime = t->stime;
1872 }
1873 
1874 static inline void task_cputime_scaled(struct task_struct *t,
1875                                        cputime_t *utimescaled,
1876                                        cputime_t *stimescaled)
1877 {
1878         if (utimescaled)
1879                 *utimescaled = t->utimescaled;
1880         if (stimescaled)
1881                 *stimescaled = t->stimescaled;
1882 }
1883 
1884 static inline cputime_t task_gtime(struct task_struct *t)
1885 {
1886         return t->gtime;
1887 }
1888 #endif
1889 extern void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
1890 extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
1891 
1892 /*
1893  * Per process flags
1894  */
1895 #define PF_EXITING      0x00000004      /* getting shut down */
1896 #define PF_EXITPIDONE   0x00000008      /* pi exit done on shut down */
1897 #define PF_VCPU         0x00000010      /* I'm a virtual CPU */
1898 #define PF_WQ_WORKER    0x00000020      /* I'm a workqueue worker */
1899 #define PF_FORKNOEXEC   0x00000040      /* forked but didn't exec */
1900 #define PF_MCE_PROCESS  0x00000080      /* process policy on mce errors */
1901 #define PF_SUPERPRIV    0x00000100      /* used super-user privileges */
1902 #define PF_DUMPCORE     0x00000200      /* dumped core */
1903 #define PF_SIGNALED     0x00000400      /* killed by a signal */
1904 #define PF_MEMALLOC     0x00000800      /* Allocating memory */
1905 #define PF_NPROC_EXCEEDED 0x00001000    /* set_user noticed that RLIMIT_NPROC was exceeded */
1906 #define PF_USED_MATH    0x00002000      /* if unset the fpu must be initialized before use */
1907 #define PF_USED_ASYNC   0x00004000      /* used async_schedule*(), used by module init */
1908 #define PF_NOFREEZE     0x00008000      /* this thread should not be frozen */
1909 #define PF_FROZEN       0x00010000      /* frozen for system suspend */
1910 #define PF_FSTRANS      0x00020000      /* inside a filesystem transaction */
1911 #define PF_KSWAPD       0x00040000      /* I am kswapd */
1912 #define PF_MEMALLOC_NOIO 0x00080000     /* Allocating memory without IO involved */
1913 #define PF_LESS_THROTTLE 0x00100000     /* Throttle me less: I clean memory */
1914 #define PF_KTHREAD      0x00200000      /* I am a kernel thread */
1915 #define PF_RANDOMIZE    0x00400000      /* randomize virtual address space */
1916 #define PF_SWAPWRITE    0x00800000      /* Allowed to write to swap */
1917 #define PF_SPREAD_PAGE  0x01000000      /* Spread page cache over cpuset */
1918 #define PF_SPREAD_SLAB  0x02000000      /* Spread some slab caches over cpuset */
1919 #define PF_NO_SETAFFINITY 0x04000000    /* Userland is not allowed to meddle with cpus_allowed */
1920 #define PF_MCE_EARLY    0x08000000      /* Early kill for mce process policy */
1921 #define PF_MUTEX_TESTER 0x20000000      /* Thread belongs to the rt mutex tester */
1922 #define PF_FREEZER_SKIP 0x40000000      /* Freezer should not count it as freezable */
1923 #define PF_SUSPEND_TASK 0x80000000      /* this thread called freeze_processes and should not be frozen */
1924 
1925 /*
1926  * Only the _current_ task can read/write to tsk->flags, but other
1927  * tasks can access tsk->flags in readonly mode for example
1928  * with tsk_used_math (like during threaded core dumping).
1929  * There is however an exception to this rule during ptrace
1930  * or during fork: the ptracer task is allowed to write to the
1931  * child->flags of its traced child (same goes for fork, the parent
1932  * can write to the child->flags), because we're guaranteed the
1933  * child is not running and in turn not changing child->flags
1934  * at the same time the parent does it.
1935  */
1936 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1937 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1938 #define clear_used_math() clear_stopped_child_used_math(current)
1939 #define set_used_math() set_stopped_child_used_math(current)
1940 #define conditional_stopped_child_used_math(condition, child) \
1941         do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1942 #define conditional_used_math(condition) \
1943         conditional_stopped_child_used_math(condition, current)
1944 #define copy_to_stopped_child_used_math(child) \
1945         do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1946 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1947 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1948 #define used_math() tsk_used_math(current)
1949 
1950 /* __GFP_IO isn't allowed if PF_MEMALLOC_NOIO is set in current->flags */
1951 static inline gfp_t memalloc_noio_flags(gfp_t flags)
1952 {
1953         if (unlikely(current->flags & PF_MEMALLOC_NOIO))
1954                 flags &= ~__GFP_IO;
1955         return flags;
1956 }
1957 
1958 static inline unsigned int memalloc_noio_save(void)
1959 {
1960         unsigned int flags = current->flags & PF_MEMALLOC_NOIO;
1961         current->flags |= PF_MEMALLOC_NOIO;
1962         return flags;
1963 }
1964 
1965 static inline void memalloc_noio_restore(unsigned int flags)
1966 {
1967         current->flags = (current->flags & ~PF_MEMALLOC_NOIO) | flags;
1968 }
1969 
1970 /*
1971  * task->jobctl flags
1972  */
1973 #define JOBCTL_STOP_SIGMASK     0xffff  /* signr of the last group stop */
1974 
1975 #define JOBCTL_STOP_DEQUEUED_BIT 16     /* stop signal dequeued */
1976 #define JOBCTL_STOP_PENDING_BIT 17      /* task should stop for group stop */
1977 #define JOBCTL_STOP_CONSUME_BIT 18      /* consume group stop count */
1978 #define JOBCTL_TRAP_STOP_BIT    19      /* trap for STOP */
1979 #define JOBCTL_TRAP_NOTIFY_BIT  20      /* trap for NOTIFY */
1980 #define JOBCTL_TRAPPING_BIT     21      /* switching to TRACED */
1981 #define JOBCTL_LISTENING_BIT    22      /* ptracer is listening for events */
1982 
1983 #define JOBCTL_STOP_DEQUEUED    (1 << JOBCTL_STOP_DEQUEUED_BIT)
1984 #define JOBCTL_STOP_PENDING     (1 << JOBCTL_STOP_PENDING_BIT)
1985 #define JOBCTL_STOP_CONSUME     (1 << JOBCTL_STOP_CONSUME_BIT)
1986 #define JOBCTL_TRAP_STOP        (1 << JOBCTL_TRAP_STOP_BIT)
1987 #define JOBCTL_TRAP_NOTIFY      (1 << JOBCTL_TRAP_NOTIFY_BIT)
1988 #define JOBCTL_TRAPPING         (1 << JOBCTL_TRAPPING_BIT)
1989 #define JOBCTL_LISTENING        (1 << JOBCTL_LISTENING_BIT)
1990 
1991 #define JOBCTL_TRAP_MASK        (JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
1992 #define JOBCTL_PENDING_MASK     (JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)
1993 
1994 extern bool task_set_jobctl_pending(struct task_struct *task,
1995                                     unsigned int mask);
1996 extern void task_clear_jobctl_trapping(struct task_struct *task);
1997 extern void task_clear_jobctl_pending(struct task_struct *task,
1998                                       unsigned int mask);
1999 
2000 #ifdef CONFIG_PREEMPT_RCU
2001 
2002 #define RCU_READ_UNLOCK_BLOCKED (1 << 0) /* blocked while in RCU read-side. */
2003 #define RCU_READ_UNLOCK_NEED_QS (1 << 1) /* RCU core needs CPU response. */
2004 
2005 static inline void rcu_copy_process(struct task_struct *p)
2006 {
2007         p->rcu_read_lock_nesting = 0;
2008         p->rcu_read_unlock_special = 0;
2009 #ifdef CONFIG_TREE_PREEMPT_RCU
2010         p->rcu_blocked_node = NULL;
2011 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
2012 #ifdef CONFIG_RCU_BOOST
2013         p->rcu_boost_mutex = NULL;
2014 #endif /* #ifdef CONFIG_RCU_BOOST */
2015         INIT_LIST_HEAD(&p->rcu_node_entry);
2016 }
2017 
2018 #else
2019 
2020 static inline void rcu_copy_process(struct task_struct *p)
2021 {
2022 }
2023 
2024 #endif
2025 
2026 static inline void tsk_restore_flags(struct task_struct *task,
2027                                 unsigned long orig_flags, unsigned long flags)
2028 {
2029         task->flags &= ~flags;
2030         task->flags |= orig_flags & flags;
2031 }
2032 
2033 #ifdef CONFIG_SMP
2034 extern void do_set_cpus_allowed(struct task_struct *p,
2035                                const struct cpumask *new_mask);
2036 
2037 extern int set_cpus_allowed_ptr(struct task_struct *p,
2038                                 const struct cpumask *new_mask);
2039 #else
2040 static inline void do_set_cpus_allowed(struct task_struct *p,
2041                                       const struct cpumask *new_mask)
2042 {
2043 }
2044 static inline int set_cpus_allowed_ptr(struct task_struct *p,
2045                                        const struct cpumask *new_mask)
2046 {
2047         if (!cpumask_test_cpu(0, new_mask))
2048                 return -EINVAL;
2049         return 0;
2050 }
2051 #endif
2052 
2053 #ifdef CONFIG_NO_HZ_COMMON
2054 void calc_load_enter_idle(void);
2055 void calc_load_exit_idle(void);
2056 #else
2057 static inline void calc_load_enter_idle(void) { }
2058 static inline void calc_load_exit_idle(void) { }
2059 #endif /* CONFIG_NO_HZ_COMMON */
2060 
2061 #ifndef CONFIG_CPUMASK_OFFSTACK
2062 static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
2063 {
2064         return set_cpus_allowed_ptr(p, &new_mask);
2065 }
2066 #endif
2067 
2068 /*
2069  * Do not use outside of architecture code which knows its limitations.
2070  *
2071  * sched_clock() has no promise of monotonicity or bounded drift between
2072  * CPUs, use (which you should not) requires disabling IRQs.
2073  *
2074  * Please use one of the three interfaces below.
2075  */
2076 extern unsigned long long notrace sched_clock(void);
2077 /*
2078  * See the comment in kernel/sched/clock.c
2079  */
2080 extern u64 cpu_clock(int cpu);
2081 extern u64 local_clock(void);
2082 extern u64 sched_clock_cpu(int cpu);
2083 
2084 
2085 extern void sched_clock_init(void);
2086 
2087 #ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
2088 static inline void sched_clock_tick(void)
2089 {
2090 }
2091 
2092 static inline void sched_clock_idle_sleep_event(void)
2093 {
2094 }
2095 
2096 static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
2097 {
2098 }
2099 #else
2100 /*
2101  * Architectures can set this to 1 if they have specified
2102  * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
2103  * but then during bootup it turns out that sched_clock()
2104  * is reliable after all:
2105  */
2106 extern int sched_clock_stable(void);
2107 extern void set_sched_clock_stable(void);
2108 extern void clear_sched_clock_stable(void);
2109 
2110 extern void sched_clock_tick(void);
2111 extern void sched_clock_idle_sleep_event(void);
2112 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2113 #endif
2114 
2115 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
2116 /*
2117  * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
2118  * The reason for this explicit opt-in is not to have perf penalty with
2119  * slow sched_clocks.
2120  */
2121 extern void enable_sched_clock_irqtime(void);
2122 extern void disable_sched_clock_irqtime(void);
2123 #else
2124 static inline void enable_sched_clock_irqtime(void) {}
2125 static inline void disable_sched_clock_irqtime(void) {}
2126 #endif
2127 
2128 extern unsigned long long
2129 task_sched_runtime(struct task_struct *task);
2130 
2131 /* sched_exec is called by processes performing an exec */
2132 #ifdef CONFIG_SMP
2133 extern void sched_exec(void);
2134 #else
2135 #define sched_exec()   {}
2136 #endif
2137 
2138 extern void sched_clock_idle_sleep_event(void);
2139 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2140 
2141 #ifdef CONFIG_HOTPLUG_CPU
2142 extern void idle_task_exit(void);
2143 #else
2144 static inline void idle_task_exit(void) {}
2145 #endif
2146 
2147 #if defined(CONFIG_NO_HZ_COMMON) && defined(CONFIG_SMP)
2148 extern void wake_up_nohz_cpu(int cpu);
2149 #else
2150 static inline void wake_up_nohz_cpu(int cpu) { }
2151 #endif
2152 
2153 #ifdef CONFIG_NO_HZ_FULL
2154 extern bool sched_can_stop_tick(void);
2155 extern u64 scheduler_tick_max_deferment(void);
2156 #else
2157 static inline bool sched_can_stop_tick(void) { return false; }
2158 #endif
2159 
2160 #ifdef CONFIG_SCHED_AUTOGROUP
2161 extern void sched_autogroup_create_attach(struct task_struct *p);
2162 extern void sched_autogroup_detach(struct task_struct *p);
2163 extern void sched_autogroup_fork(struct signal_struct *sig);
2164 extern void sched_autogroup_exit(struct signal_struct *sig);
2165 #ifdef CONFIG_PROC_FS
2166 extern void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m);
2167 extern int proc_sched_autogroup_set_nice(struct task_struct *p, int nice);
2168 #endif
2169 #else
2170 static inline void sched_autogroup_create_attach(struct task_struct *p) { }
2171 static inline void sched_autogroup_detach(struct task_struct *p) { }
2172 static inline void sched_autogroup_fork(struct signal_struct *sig) { }
2173 static inline void sched_autogroup_exit(struct signal_struct *sig) { }
2174 #endif
2175 
2176 extern int yield_to(struct task_struct *p, bool preempt);
2177 extern void set_user_nice(struct task_struct *p, long nice);
2178 extern int task_prio(const struct task_struct *p);
2179 /**
2180  * task_nice - return the nice value of a given task.
2181  * @p: the task in question.
2182  *
2183  * Return: The nice value [ -20 ... 0 ... 19 ].
2184  */
2185 static inline int task_nice(const struct task_struct *p)
2186 {
2187         return PRIO_TO_NICE((p)->static_prio);
2188 }
2189 extern int can_nice(const struct task_struct *p, const int nice);
2190 extern int task_curr(const struct task_struct *p);
2191 extern int idle_cpu(int cpu);
2192 extern int sched_setscheduler(struct task_struct *, int,
2193                               const struct sched_param *);
2194 extern int sched_setscheduler_nocheck(struct task_struct *, int,
2195                                       const struct sched_param *);
2196 extern int sched_setattr(struct task_struct *,
2197                          const struct sched_attr *);
2198 extern struct task_struct *idle_task(int cpu);
2199 /**
2200  * is_idle_task - is the specified task an idle task?
2201  * @p: the task in question.
2202  *
2203  * Return: 1 if @p is an idle task. 0 otherwise.
2204  */
2205 static inline bool is_idle_task(const struct task_struct *p)
2206 {
2207         return p->pid == 0;
2208 }
2209 extern struct task_struct *curr_task(int cpu);
2210 extern void set_curr_task(int cpu, struct task_struct *p);
2211 
2212 void yield(void);
2213 
2214 /*
2215  * The default (Linux) execution domain.
2216  */
2217 extern struct exec_domain       default_exec_domain;
2218 
2219 union thread_union {
2220         struct thread_info thread_info;
2221         unsigned long stack[THREAD_SIZE/sizeof(long)];
2222 };
2223 
2224 #ifndef __HAVE_ARCH_KSTACK_END
2225 static inline int kstack_end(void *addr)
2226 {
2227         /* Reliable end of stack detection:
2228          * Some APM bios versions misalign the stack
2229          */
2230         return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
2231 }
2232 #endif
2233 
2234 extern union thread_union init_thread_union;
2235 extern struct task_struct init_task;
2236 
2237 extern struct   mm_struct init_mm;
2238 
2239 extern struct pid_namespace init_pid_ns;
2240 
2241 /*
2242  * find a task by one of its numerical ids
2243  *
2244  * find_task_by_pid_ns():
2245  *      finds a task by its pid in the specified namespace
2246  * find_task_by_vpid():
2247  *      finds a task by its virtual pid
2248  *
2249  * see also find_vpid() etc in include/linux/pid.h
2250  */
2251 
2252 extern struct task_struct *find_task_by_vpid(pid_t nr);
2253 extern struct task_struct *find_task_by_pid_ns(pid_t nr,
2254                 struct pid_namespace *ns);
2255 
2256 /* per-UID process charging. */
2257 extern struct user_struct * alloc_uid(kuid_t);
2258 static inline struct user_struct *get_uid(struct user_struct *u)
2259 {
2260         atomic_inc(&u->__count);
2261         return u;
2262 }
2263 extern void free_uid(struct user_struct *);
2264 
2265 #include <asm/current.h>
2266 
2267 extern void xtime_update(unsigned long ticks);
2268 
2269 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2270 extern int wake_up_process(struct task_struct *tsk);
2271 extern void wake_up_new_task(struct task_struct *tsk);
2272 #ifdef CONFIG_SMP
2273  extern void kick_process(struct task_struct *tsk);
2274 #else
2275  static inline void kick_process(struct task_struct *tsk) { }
2276 #endif
2277 extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
2278 extern void sched_dead(struct task_struct *p);
2279 
2280 extern void proc_caches_init(void);
2281 extern void flush_signals(struct task_struct *);
2282 extern void __flush_signals(struct task_struct *);
2283 extern void ignore_signals(struct task_struct *);
2284 extern void flush_signal_handlers(struct task_struct *, int force_default);
2285 extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
2286 
2287 static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
2288 {
2289         unsigned long flags;
2290         int ret;
2291 
2292         spin_lock_irqsave(&tsk->sighand->siglock, flags);
2293         ret = dequeue_signal(tsk, mask, info);
2294         spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
2295 
2296         return ret;
2297 }
2298 
2299 extern void block_all_signals(int (*notifier)(void *priv), void *priv,
2300                               sigset_t *mask);
2301 extern void unblock_all_signals(void);
2302 extern void release_task(struct task_struct * p);
2303 extern int send_sig_info(int, struct siginfo *, struct task_struct *);
2304 extern int force_sigsegv(int, struct task_struct *);
2305 extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2306 extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
2307 extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2308 extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *,
2309                                 const struct cred *, u32);
2310 extern int kill_pgrp(struct pid *pid, int sig, int priv);
2311 extern int kill_pid(struct pid *pid, int sig, int priv);
2312 extern int kill_proc_info(int, struct siginfo *, pid_t);
2313 extern __must_check bool do_notify_parent(struct task_struct *, int);
2314 extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
2315 extern void force_sig(int, struct task_struct *);
2316 extern int send_sig(int, struct task_struct *, int);
2317 extern int zap_other_threads(struct task_struct *p);
2318 extern struct sigqueue *sigqueue_alloc(void);
2319 extern void sigqueue_free(struct sigqueue *);
2320 extern int send_sigqueue(struct sigqueue *,  struct task_struct *, int group);
2321 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
2322 
2323 static inline void restore_saved_sigmask(void)
2324 {
2325         if (test_and_clear_restore_sigmask())
2326                 __set_current_blocked(&current->saved_sigmask);
2327 }
2328 
2329 static inline sigset_t *sigmask_to_save(void)
2330 {
2331         sigset_t *res = &current->blocked;
2332         if (unlikely(test_restore_sigmask()))
2333                 res = &current->saved_sigmask;
2334         return res;
2335 }
2336 
2337 static inline int kill_cad_pid(int sig, int priv)
2338 {
2339         return kill_pid(cad_pid, sig, priv);
2340 }
2341 
2342 /* These can be the second arg to send_sig_info/send_group_sig_info.  */
2343 #define SEND_SIG_NOINFO ((struct siginfo *) 0)
2344 #define SEND_SIG_PRIV   ((struct siginfo *) 1)
2345 #define SEND_SIG_FORCED ((struct siginfo *) 2)
2346 
2347 /*
2348  * True if we are on the alternate signal stack.
2349  */
2350 static inline int on_sig_stack(unsigned long sp)
2351 {
2352 #ifdef CONFIG_STACK_GROWSUP
2353         return sp >= current->sas_ss_sp &&
2354                 sp - current->sas_ss_sp < current->sas_ss_size;
2355 #else
2356         return sp > current->sas_ss_sp &&
2357                 sp - current->sas_ss_sp <= current->sas_ss_size;
2358 #endif
2359 }
2360 
2361 static inline int sas_ss_flags(unsigned long sp)
2362 {
2363         return (current->sas_ss_size == 0 ? SS_DISABLE
2364                 : on_sig_stack(sp) ? SS_ONSTACK : 0);
2365 }
2366 
2367 static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig)
2368 {
2369         if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))
2370 #ifdef CONFIG_STACK_GROWSUP
2371                 return current->sas_ss_sp;
2372 #else
2373                 return current->sas_ss_sp + current->sas_ss_size;
2374 #endif
2375         return sp;
2376 }
2377 
2378 /*
2379  * Routines for handling mm_structs
2380  */
2381 extern struct mm_struct * mm_alloc(void);
2382 
2383 /* mmdrop drops the mm and the page tables */
2384 extern void __mmdrop(struct mm_struct *);
2385 static inline void mmdrop(struct mm_struct * mm)
2386 {
2387         if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2388                 __mmdrop(mm);
2389 }
2390 
2391 /* mmput gets rid of the mappings and all user-space */
2392 extern void mmput(struct mm_struct *);
2393 /* Grab a reference to a task's mm, if it is not already going away */
2394 extern struct mm_struct *get_task_mm(struct task_struct *task);
2395 /*
2396  * Grab a reference to a task's mm, if it is not already going away
2397  * and ptrace_may_access with the mode parameter passed to it
2398  * succeeds.
2399  */
2400 extern struct mm_struct *mm_access(struct task_struct *task, unsigned int mode);
2401 /* Remove the current tasks stale references to the old mm_struct */
2402 extern void mm_release(struct task_struct *, struct mm_struct *);
2403 
2404 extern int copy_thread(unsigned long, unsigned long, unsigned long,
2405                         struct task_struct *);
2406 extern void flush_thread(void);
2407 extern void exit_thread(void);
2408 
2409 extern void exit_files(struct task_struct *);
2410 extern void __cleanup_sighand(struct sighand_struct *);
2411 
2412 extern void exit_itimers(struct signal_struct *);
2413 extern void flush_itimer_signals(void);
2414 
2415 extern void do_group_exit(int);
2416 
2417 extern int do_execve(struct filename *,
2418                      const char __user * const __user *,
2419                      const char __user * const __user *);
2420 extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
2421 struct task_struct *fork_idle(int);
2422 extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
2423 
2424 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
2425 static inline void set_task_comm(struct task_struct *tsk, const char *from)
2426 {
2427         __set_task_comm(tsk, from, false);
2428 }
2429 extern char *get_task_comm(char *to, struct task_struct *tsk);
2430 
2431 #ifdef CONFIG_SMP
2432 void scheduler_ipi(void);
2433 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
2434 #else
2435 static inline void scheduler_ipi(void) { }
2436 static inline unsigned long wait_task_inactive(struct task_struct *p,
2437                                                long match_state)
2438 {
2439         return 1;
2440 }
2441 #endif
2442 
2443 #define next_task(p) \
2444         list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
2445 
2446 #define for_each_process(p) \
2447         for (p = &init_task ; (p = next_task(p)) != &init_task ; )
2448 
2449 extern bool current_is_single_threaded(void);
2450 
2451 /*
2452  * Careful: do_each_thread/while_each_thread is a double loop so
2453  *          'break' will not work as expected - use goto instead.
2454  */
2455 #define do_each_thread(g, t) \
2456         for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
2457 
2458 #define while_each_thread(g, t) \
2459         while ((t = next_thread(t)) != g)
2460 
2461 #define __for_each_thread(signal, t)    \
2462         list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node)
2463 
2464 #define for_each_thread(p, t)           \
2465         __for_each_thread((p)->signal, t)
2466 
2467 /* Careful: this is a double loop, 'break' won't work as expected. */
2468 #define for_each_process_thread(p, t)   \
2469         for_each_process(p) for_each_thread(p, t)
2470 
2471 static inline int get_nr_threads(struct task_struct *tsk)
2472 {
2473         return tsk->signal->nr_threads;
2474 }
2475 
2476 static inline bool thread_group_leader(struct task_struct *p)
2477 {
2478         return p->exit_signal >= 0;
2479 }
2480 
2481 /* Do to the insanities of de_thread it is possible for a process
2482  * to have the pid of the thread group leader without actually being
2483  * the thread group leader.  For iteration through the pids in proc
2484  * all we care about is that we have a task with the appropriate
2485  * pid, we don't actually care if we have the right task.
2486  */
2487 static inline bool has_group_leader_pid(struct task_struct *p)
2488 {
2489         return task_pid(p) == p->signal->leader_pid;
2490 }
2491 
2492 static inline
2493 bool same_thread_group(struct task_struct *p1, struct task_struct *p2)
2494 {
2495         return p1->signal == p2->signal;
2496 }
2497 
2498 static inline struct task_struct *next_thread(const struct task_struct *p)
2499 {
2500         return list_entry_rcu(p->thread_group.next,
2501                               struct task_struct, thread_group);
2502 }
2503 
2504 static inline int thread_group_empty(struct task_struct *p)
2505 {
2506         return list_empty(&p->thread_group);
2507 }
2508 
2509 #define delay_group_leader(p) \
2510                 (thread_group_leader(p) && !thread_group_empty(p))
2511 
2512 /*
2513  * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
2514  * subscriptions and synchronises with wait4().  Also used in procfs.  Also
2515  * pins the final release of task.io_context.  Also protects ->cpuset and
2516  * ->cgroup.subsys[]. And ->vfork_done.
2517  *
2518  * Nests both inside and outside of read_lock(&tasklist_lock).
2519  * It must not be nested with write_lock_irq(&tasklist_lock),
2520  * neither inside nor outside.
2521  */
2522 static inline void task_lock(struct task_struct *p)
2523 {
2524         spin_lock(&p->alloc_lock);
2525 }
2526 
2527 static inline void task_unlock(struct task_struct *p)
2528 {
2529         spin_unlock(&p->alloc_lock);
2530 }
2531 
2532 extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
2533                                                         unsigned long *flags);
2534 
2535 static inline struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
2536                                                        unsigned long *flags)
2537 {
2538         struct sighand_struct *ret;
2539 
2540         ret = __lock_task_sighand(tsk, flags);
2541         (void)__cond_lock(&tsk->sighand->siglock, ret);
2542         return ret;
2543 }
2544 
2545 static inline void unlock_task_sighand(struct task_struct *tsk,
2546                                                 unsigned long *flags)
2547 {
2548         spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
2549 }
2550 
2551 #ifdef CONFIG_CGROUPS
2552 static inline void threadgroup_change_begin(struct task_struct *tsk)
2553 {
2554         down_read(&tsk->signal->group_rwsem);
2555 }
2556 static inline void threadgroup_change_end(struct task_struct *tsk)
2557 {
2558         up_read(&tsk->signal->group_rwsem);
2559 }
2560 
2561 /**
2562  * threadgroup_lock - lock threadgroup
2563  * @tsk: member task of the threadgroup to lock
2564  *
2565  * Lock the threadgroup @tsk belongs to.  No new task is allowed to enter
2566  * and member tasks aren't allowed to exit (as indicated by PF_EXITING) or
2567  * change ->group_leader/pid.  This is useful for cases where the threadgroup
2568  * needs to stay stable across blockable operations.
2569  *
2570  * fork and exit paths explicitly call threadgroup_change_{begin|end}() for
2571  * synchronization.  While held, no new task will be added to threadgroup
2572  * and no existing live task will have its PF_EXITING set.
2573  *
2574  * de_thread() does threadgroup_change_{begin|end}() when a non-leader
2575  * sub-thread becomes a new leader.
2576  */
2577 static inline void threadgroup_lock(struct task_struct *tsk)
2578 {
2579         down_write(&tsk->signal->group_rwsem);
2580 }
2581 
2582 /**
2583  * threadgroup_unlock - unlock threadgroup
2584  * @tsk: member task of the threadgroup to unlock
2585  *
2586  * Reverse threadgroup_lock().
2587  */
2588 static inline void threadgroup_unlock(struct task_struct *tsk)
2589 {
2590         up_write(&tsk->signal->group_rwsem);
2591 }
2592 #else
2593 static inline void threadgroup_change_begin(struct task_struct *tsk) {}
2594 static inline void threadgroup_change_end(struct task_struct *tsk) {}
2595 static inline void threadgroup_lock(struct task_struct *tsk) {}
2596 static inline void threadgroup_unlock(struct task_struct *tsk) {}
2597 #endif
2598 
2599 #ifndef __HAVE_THREAD_FUNCTIONS
2600 
2601 #define task_thread_info(task)  ((struct thread_info *)(task)->stack)
2602 #define task_stack_page(task)   ((task)->stack)
2603 
2604 static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
2605 {
2606         *task_thread_info(p) = *task_thread_info(org);
2607         task_thread_info(p)->task = p;
2608 }
2609 
2610 static inline unsigned long *end_of_stack(struct task_struct *p)
2611 {
2612         return (unsigned long *)(task_thread_info(p) + 1);
2613 }
2614 
2615 #endif
2616 
2617 static inline int object_is_on_stack(void *obj)
2618 {
2619         void *stack = task_stack_page(current);
2620 
2621         return (obj >= stack) && (obj < (stack + THREAD_SIZE));
2622 }
2623 
2624 extern void thread_info_cache_init(void);
2625 
2626 #ifdef CONFIG_DEBUG_STACK_USAGE
2627 static inline unsigned long stack_not_used(struct task_struct *p)
2628 {
2629         unsigned long *n = end_of_stack(p);
2630 
2631         do {    /* Skip over canary */
2632                 n++;
2633         } while (!*n);
2634 
2635         return (unsigned long)n - (unsigned long)end_of_stack(p);
2636 }
2637 #endif
2638 
2639 /* set thread flags in other task's structures
2640  * - see asm/thread_info.h for TIF_xxxx flags available
2641  */
2642 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2643 {
2644         set_ti_thread_flag(task_thread_info(tsk), flag);
2645 }
2646 
2647 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2648 {
2649         clear_ti_thread_flag(task_thread_info(tsk), flag);
2650 }
2651 
2652 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2653 {
2654         return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2655 }
2656 
2657 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2658 {
2659         return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2660 }
2661 
2662 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2663 {
2664         return test_ti_thread_flag(task_thread_info(tsk), flag);
2665 }
2666 
2667 static inline void set_tsk_need_resched(struct task_struct *tsk)
2668 {
2669         set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2670 }
2671 
2672 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2673 {
2674         clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2675 }
2676 
2677 static inline int test_tsk_need_resched(struct task_struct *tsk)
2678 {
2679         return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2680 }
2681 
2682 static inline int restart_syscall(void)
2683 {
2684         set_tsk_thread_flag(current, TIF_SIGPENDING);
2685         return -ERESTARTNOINTR;
2686 }
2687 
2688 static inline int signal_pending(struct task_struct *p)
2689 {
2690         return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
2691 }
2692 
2693 static inline int __fatal_signal_pending(struct task_struct *p)
2694 {
2695         return unlikely(sigismember(&p->pending.signal, SIGKILL));
2696 }
2697 
2698 static inline int fatal_signal_pending(struct task_struct *p)
2699 {
2700         return signal_pending(p) && __fatal_signal_pending(p);
2701 }
2702 
2703 static inline int signal_pending_state(long state, struct task_struct *p)
2704 {
2705         if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
2706                 return 0;
2707         if (!signal_pending(p))
2708                 return 0;
2709 
2710         return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
2711 }
2712 
2713 /*
2714  * cond_resched() and cond_resched_lock(): latency reduction via
2715  * explicit rescheduling in places that are safe. The return
2716  * value indicates whether a reschedule was done in fact.
2717  * cond_resched_lock() will drop the spinlock before scheduling,
2718  * cond_resched_softirq() will enable bhs before scheduling.
2719  */
2720 extern int _cond_resched(void);
2721 
2722 #define cond_resched() ({                       \
2723         __might_sleep(__FILE__, __LINE__, 0);   \
2724         _cond_resched();                        \
2725 })
2726 
2727 extern int __cond_resched_lock(spinlock_t *lock);
2728 
2729 #ifdef CONFIG_PREEMPT_COUNT
2730 #define PREEMPT_LOCK_OFFSET     PREEMPT_OFFSET
2731 #else
2732 #define PREEMPT_LOCK_OFFSET     0
2733 #endif
2734 
2735 #define cond_resched_lock(lock) ({                              \
2736         __might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET); \
2737         __cond_resched_lock(lock);                              \
2738 })
2739 
2740 extern int __cond_resched_softirq(void);
2741 
2742 #define cond_resched_softirq() ({                                       \
2743         __might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET);      \
2744         __cond_resched_softirq();                                       \
2745 })
2746 
2747 static inline void cond_resched_rcu(void)
2748 {
2749 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
2750         rcu_read_unlock();
2751         cond_resched();
2752         rcu_read_lock();
2753 #endif
2754 }
2755 
2756 /*
2757  * Does a critical section need to be broken due to another
2758  * task waiting?: (technically does not depend on CONFIG_PREEMPT,
2759  * but a general need for low latency)
2760  */
2761 static inline int spin_needbreak(spinlock_t *lock)
2762 {
2763 #ifdef CONFIG_PREEMPT
2764         return spin_is_contended(lock);
2765 #else
2766         return 0;
2767 #endif
2768 }
2769 
2770 /*
2771  * Idle thread specific functions to determine the need_resched
2772  * polling state.
2773  */
2774 #ifdef TIF_POLLING_NRFLAG
2775 static inline int tsk_is_polling(struct task_struct *p)
2776 {
2777         return test_tsk_thread_flag(p, TIF_POLLING_NRFLAG);
2778 }
2779 
2780 static inline void __current_set_polling(void)
2781 {
2782         set_thread_flag(TIF_POLLING_NRFLAG);
2783 }
2784 
2785 static inline bool __must_check current_set_polling_and_test(void)
2786 {
2787         __current_set_polling();
2788 
2789         /*
2790          * Polling state must be visible before we test NEED_RESCHED,
2791          * paired by resched_task()
2792          */
2793         smp_mb__after_atomic();
2794 
2795         return unlikely(tif_need_resched());
2796 }
2797 
2798 static inline void __current_clr_polling(void)
2799 {
2800         clear_thread_flag(TIF_POLLING_NRFLAG);
2801 }
2802 
2803 static inline bool __must_check current_clr_polling_and_test(void)
2804 {
2805         __current_clr_polling();
2806 
2807         /*
2808          * Polling state must be visible before we test NEED_RESCHED,
2809          * paired by resched_task()
2810          */
2811         smp_mb__after_atomic();
2812 
2813         return unlikely(tif_need_resched());
2814 }
2815 
2816 #else
2817 static inline int tsk_is_polling(struct task_struct *p) { return 0; }
2818 static inline void __current_set_polling(void) { }
2819 static inline void __current_clr_polling(void) { }
2820 
2821 static inline bool __must_check current_set_polling_and_test(void)
2822 {
2823         return unlikely(tif_need_resched());
2824 }
2825 static inline bool __must_check current_clr_polling_and_test(void)
2826 {
2827         return unlikely(tif_need_resched());
2828 }
2829 #endif
2830 
2831 static inline void current_clr_polling(void)
2832 {
2833         __current_clr_polling();
2834 
2835         /*
2836          * Ensure we check TIF_NEED_RESCHED after we clear the polling bit.
2837          * Once the bit is cleared, we'll get IPIs with every new
2838          * TIF_NEED_RESCHED and the IPI handler, scheduler_ipi(), will also
2839          * fold.
2840          */
2841         smp_mb(); /* paired with resched_task() */
2842 
2843         preempt_fold_need_resched();
2844 }
2845 
2846 static __always_inline bool need_resched(void)
2847 {
2848         return unlikely(tif_need_resched());
2849 }
2850 
2851 /*
2852  * Thread group CPU time accounting.
2853  */
2854 void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
2855 void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
2856 
2857 static inline void thread_group_cputime_init(struct signal_struct *sig)
2858 {
2859         raw_spin_lock_init(&sig->cputimer.lock);
2860 }
2861 
2862 /*
2863  * Reevaluate whether the task has signals pending delivery.
2864  * Wake the task if so.
2865  * This is required every time the blocked sigset_t changes.
2866  * callers must hold sighand->siglock.
2867  */
2868 extern void recalc_sigpending_and_wake(struct task_struct *t);
2869 extern void recalc_sigpending(void);
2870 
2871 extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
2872 
2873 static inline void signal_wake_up(struct task_struct *t, bool resume)
2874 {
2875         signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0);
2876 }
2877 static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
2878 {
2879         signal_wake_up_state(t, resume ? __TASK_TRACED : 0);
2880 }
2881 
2882 /*
2883  * Wrappers for p->thread_info->cpu access. No-op on UP.
2884  */
2885 #ifdef CONFIG_SMP
2886 
2887 static inline unsigned int task_cpu(const struct task_struct *p)
2888 {
2889         return task_thread_info(p)->cpu;
2890 }
2891 
2892 static inline int task_node(const struct task_struct *p)
2893 {
2894         return cpu_to_node(task_cpu(p));
2895 }
2896 
2897 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2898 
2899 #else
2900 
2901 static inline unsigned int task_cpu(const struct task_struct *p)
2902 {
2903         return 0;
2904 }
2905 
2906 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2907 {
2908 }
2909 
2910 #endif /* CONFIG_SMP */
2911 
2912 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2913 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2914 
2915 #ifdef CONFIG_CGROUP_SCHED
2916 extern struct task_group root_task_group;
2917 #endif /* CONFIG_CGROUP_SCHED */
2918 
2919 extern int task_can_switch_user(struct user_struct *up,
2920                                         struct task_struct *tsk);
2921 
2922 #ifdef CONFIG_TASK_XACCT
2923 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2924 {
2925         tsk->ioac.rchar += amt;
2926 }
2927 
2928 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2929 {
2930         tsk->ioac.wchar += amt;
2931 }
2932 
2933 static inline void inc_syscr(struct task_struct *tsk)
2934 {
2935         tsk->ioac.syscr++;
2936 }
2937 
2938 static inline void inc_syscw(struct task_struct *tsk)
2939 {
2940         tsk->ioac.syscw++;
2941 }
2942 #else
2943 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2944 {
2945 }
2946 
2947 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2948 {
2949 }
2950 
2951 static inline void inc_syscr(struct task_struct *tsk)
2952 {
2953 }
2954 
2955 static inline void inc_syscw(struct task_struct *tsk)
2956 {
2957 }
2958 #endif
2959 
2960 #ifndef TASK_SIZE_OF
2961 #define TASK_SIZE_OF(tsk)       TASK_SIZE
2962 #endif
2963 
2964 #ifdef CONFIG_MEMCG
2965 extern void mm_update_next_owner(struct mm_struct *mm);
2966 extern void mm_init_owner(struct mm_struct *mm, struct task_struct *p);
2967 #else
2968 static inline void mm_update_next_owner(struct mm_struct *mm)
2969 {
2970 }
2971 
2972 static inline void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
2973 {
2974 }
2975 #endif /* CONFIG_MEMCG */
2976 
2977 static inline unsigned long task_rlimit(const struct task_struct *tsk,
2978                 unsigned int limit)
2979 {
2980         return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_cur);
2981 }
2982 
2983 static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
2984                 unsigned int limit)
2985 {
2986         return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_max);
2987 }
2988 
2989 static inline unsigned long rlimit(unsigned int limit)
2990 {
2991         return task_rlimit(current, limit);
2992 }
2993 
2994 static inline unsigned long rlimit_max(unsigned int limit)
2995 {
2996         return task_rlimit_max(current, limit);
2997 }
2998 
2999 #endif
3000 

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