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TOMOYO Linux Cross Reference
Linux/include/linux/sched.h

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  1 #ifndef _LINUX_SCHED_H
  2 #define _LINUX_SCHED_H
  3 
  4 #include <uapi/linux/sched.h>
  5 
  6 
  7 struct ccs_domain_info;
  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/rbtree.h>
 22 #include <linux/thread_info.h>
 23 #include <linux/cpumask.h>
 24 #include <linux/errno.h>
 25 #include <linux/nodemask.h>
 26 #include <linux/mm_types.h>
 27 
 28 #include <asm/page.h>
 29 #include <asm/ptrace.h>
 30 #include <asm/cputime.h>
 31 
 32 #include <linux/smp.h>
 33 #include <linux/sem.h>
 34 #include <linux/signal.h>
 35 #include <linux/compiler.h>
 36 #include <linux/completion.h>
 37 #include <linux/pid.h>
 38 #include <linux/percpu.h>
 39 #include <linux/topology.h>
 40 #include <linux/proportions.h>
 41 #include <linux/seccomp.h>
 42 #include <linux/rcupdate.h>
 43 #include <linux/rculist.h>
 44 #include <linux/rtmutex.h>
 45 
 46 #include <linux/time.h>
 47 #include <linux/param.h>
 48 #include <linux/resource.h>
 49 #include <linux/timer.h>
 50 #include <linux/hrtimer.h>
 51 #include <linux/task_io_accounting.h>
 52 #include <linux/latencytop.h>
 53 #include <linux/cred.h>
 54 #include <linux/llist.h>
 55 #include <linux/uidgid.h>
 56 
 57 #include <asm/processor.h>
 58 
 59 struct exec_domain;
 60 struct futex_pi_state;
 61 struct robust_list_head;
 62 struct bio_list;
 63 struct fs_struct;
 64 struct perf_event_context;
 65 struct blk_plug;
 66 
 67 /*
 68  * List of flags we want to share for kernel threads,
 69  * if only because they are not used by them anyway.
 70  */
 71 #define CLONE_KERNEL    (CLONE_FS | CLONE_FILES | CLONE_SIGHAND)
 72 
 73 /*
 74  * These are the constant used to fake the fixed-point load-average
 75  * counting. Some notes:
 76  *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
 77  *    a load-average precision of 10 bits integer + 11 bits fractional
 78  *  - if you want to count load-averages more often, you need more
 79  *    precision, or rounding will get you. With 2-second counting freq,
 80  *    the EXP_n values would be 1981, 2034 and 2043 if still using only
 81  *    11 bit fractions.
 82  */
 83 extern unsigned long avenrun[];         /* Load averages */
 84 extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
 85 
 86 #define FSHIFT          11              /* nr of bits of precision */
 87 #define FIXED_1         (1<<FSHIFT)     /* 1.0 as fixed-point */
 88 #define LOAD_FREQ       (5*HZ+1)        /* 5 sec intervals */
 89 #define EXP_1           1884            /* 1/exp(5sec/1min) as fixed-point */
 90 #define EXP_5           2014            /* 1/exp(5sec/5min) */
 91 #define EXP_15          2037            /* 1/exp(5sec/15min) */
 92 
 93 #define CALC_LOAD(load,exp,n) \
 94         load *= exp; \
 95         load += n*(FIXED_1-exp); \
 96         load >>= FSHIFT;
 97 
 98 extern unsigned long total_forks;
 99 extern int nr_threads;
100 DECLARE_PER_CPU(unsigned long, process_counts);
101 extern int nr_processes(void);
102 extern unsigned long nr_running(void);
103 extern unsigned long nr_uninterruptible(void);
104 extern unsigned long nr_iowait(void);
105 extern unsigned long nr_iowait_cpu(int cpu);
106 extern unsigned long this_cpu_load(void);
107 
108 
109 extern void calc_global_load(unsigned long ticks);
110 extern void update_cpu_load_nohz(void);
111 
112 extern unsigned long get_parent_ip(unsigned long addr);
113 
114 struct seq_file;
115 struct cfs_rq;
116 struct task_group;
117 #ifdef CONFIG_SCHED_DEBUG
118 extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
119 extern void proc_sched_set_task(struct task_struct *p);
120 extern void
121 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
122 #else
123 static inline void
124 proc_sched_show_task(struct task_struct *p, struct seq_file *m)
125 {
126 }
127 static inline void proc_sched_set_task(struct task_struct *p)
128 {
129 }
130 static inline void
131 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
132 {
133 }
134 #endif
135 
136 /*
137  * Task state bitmask. NOTE! These bits are also
138  * encoded in fs/proc/array.c: get_task_state().
139  *
140  * We have two separate sets of flags: task->state
141  * is about runnability, while task->exit_state are
142  * about the task exiting. Confusing, but this way
143  * modifying one set can't modify the other one by
144  * mistake.
145  */
146 #define TASK_RUNNING            0
147 #define TASK_INTERRUPTIBLE      1
148 #define TASK_UNINTERRUPTIBLE    2
149 #define __TASK_STOPPED          4
150 #define __TASK_TRACED           8
151 /* in tsk->exit_state */
152 #define EXIT_ZOMBIE             16
153 #define EXIT_DEAD               32
154 /* in tsk->state again */
155 #define TASK_DEAD               64
156 #define TASK_WAKEKILL           128
157 #define TASK_WAKING             256
158 #define TASK_STATE_MAX          512
159 
160 #define TASK_STATE_TO_CHAR_STR "RSDTtZXxKW"
161 
162 extern char ___assert_task_state[1 - 2*!!(
163                 sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
164 
165 /* Convenience macros for the sake of set_task_state */
166 #define TASK_KILLABLE           (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
167 #define TASK_STOPPED            (TASK_WAKEKILL | __TASK_STOPPED)
168 #define TASK_TRACED             (TASK_WAKEKILL | __TASK_TRACED)
169 
170 /* Convenience macros for the sake of wake_up */
171 #define TASK_NORMAL             (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
172 #define TASK_ALL                (TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
173 
174 /* get_task_state() */
175 #define TASK_REPORT             (TASK_RUNNING | TASK_INTERRUPTIBLE | \
176                                  TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
177                                  __TASK_TRACED)
178 
179 #define task_is_traced(task)    ((task->state & __TASK_TRACED) != 0)
180 #define task_is_stopped(task)   ((task->state & __TASK_STOPPED) != 0)
181 #define task_is_dead(task)      ((task)->exit_state != 0)
182 #define task_is_stopped_or_traced(task) \
183                         ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
184 #define task_contributes_to_load(task)  \
185                                 ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
186                                  (task->flags & PF_FROZEN) == 0)
187 
188 #define __set_task_state(tsk, state_value)              \
189         do { (tsk)->state = (state_value); } while (0)
190 #define set_task_state(tsk, state_value)                \
191         set_mb((tsk)->state, (state_value))
192 
193 /*
194  * set_current_state() includes a barrier so that the write of current->state
195  * is correctly serialised wrt the caller's subsequent test of whether to
196  * actually sleep:
197  *
198  *      set_current_state(TASK_UNINTERRUPTIBLE);
199  *      if (do_i_need_to_sleep())
200  *              schedule();
201  *
202  * If the caller does not need such serialisation then use __set_current_state()
203  */
204 #define __set_current_state(state_value)                        \
205         do { current->state = (state_value); } while (0)
206 #define set_current_state(state_value)          \
207         set_mb(current->state, (state_value))
208 
209 /* Task command name length */
210 #define TASK_COMM_LEN 16
211 
212 #include <linux/spinlock.h>
213 
214 /*
215  * This serializes "schedule()" and also protects
216  * the run-queue from deletions/modifications (but
217  * _adding_ to the beginning of the run-queue has
218  * a separate lock).
219  */
220 extern rwlock_t tasklist_lock;
221 extern spinlock_t mmlist_lock;
222 
223 struct task_struct;
224 
225 #ifdef CONFIG_PROVE_RCU
226 extern int lockdep_tasklist_lock_is_held(void);
227 #endif /* #ifdef CONFIG_PROVE_RCU */
228 
229 extern void sched_init(void);
230 extern void sched_init_smp(void);
231 extern asmlinkage void schedule_tail(struct task_struct *prev);
232 extern void init_idle(struct task_struct *idle, int cpu);
233 extern void init_idle_bootup_task(struct task_struct *idle);
234 
235 extern int runqueue_is_locked(int cpu);
236 
237 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ)
238 extern void nohz_balance_enter_idle(int cpu);
239 extern void set_cpu_sd_state_idle(void);
240 extern int get_nohz_timer_target(void);
241 #else
242 static inline void nohz_balance_enter_idle(int cpu) { }
243 static inline void set_cpu_sd_state_idle(void) { }
244 #endif
245 
246 /*
247  * Only dump TASK_* tasks. (0 for all tasks)
248  */
249 extern void show_state_filter(unsigned long state_filter);
250 
251 static inline void show_state(void)
252 {
253         show_state_filter(0);
254 }
255 
256 extern void show_regs(struct pt_regs *);
257 
258 /*
259  * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
260  * task), SP is the stack pointer of the first frame that should be shown in the back
261  * trace (or NULL if the entire call-chain of the task should be shown).
262  */
263 extern void show_stack(struct task_struct *task, unsigned long *sp);
264 
265 void io_schedule(void);
266 long io_schedule_timeout(long timeout);
267 
268 extern void cpu_init (void);
269 extern void trap_init(void);
270 extern void update_process_times(int user);
271 extern void scheduler_tick(void);
272 
273 extern void sched_show_task(struct task_struct *p);
274 
275 #ifdef CONFIG_LOCKUP_DETECTOR
276 extern void touch_softlockup_watchdog(void);
277 extern void touch_softlockup_watchdog_sync(void);
278 extern void touch_all_softlockup_watchdogs(void);
279 extern int proc_dowatchdog_thresh(struct ctl_table *table, int write,
280                                   void __user *buffer,
281                                   size_t *lenp, loff_t *ppos);
282 extern unsigned int  softlockup_panic;
283 void lockup_detector_init(void);
284 #else
285 static inline void touch_softlockup_watchdog(void)
286 {
287 }
288 static inline void touch_softlockup_watchdog_sync(void)
289 {
290 }
291 static inline void touch_all_softlockup_watchdogs(void)
292 {
293 }
294 static inline void lockup_detector_init(void)
295 {
296 }
297 #endif
298 
299 #ifdef CONFIG_DETECT_HUNG_TASK
300 extern unsigned int  sysctl_hung_task_panic;
301 extern unsigned long sysctl_hung_task_check_count;
302 extern unsigned long sysctl_hung_task_timeout_secs;
303 extern unsigned long sysctl_hung_task_warnings;
304 extern int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
305                                          void __user *buffer,
306                                          size_t *lenp, loff_t *ppos);
307 #else
308 /* Avoid need for ifdefs elsewhere in the code */
309 enum { sysctl_hung_task_timeout_secs = 0 };
310 #endif
311 
312 /* Attach to any functions which should be ignored in wchan output. */
313 #define __sched         __attribute__((__section__(".sched.text")))
314 
315 /* Linker adds these: start and end of __sched functions */
316 extern char __sched_text_start[], __sched_text_end[];
317 
318 /* Is this address in the __sched functions? */
319 extern int in_sched_functions(unsigned long addr);
320 
321 #define MAX_SCHEDULE_TIMEOUT    LONG_MAX
322 extern signed long schedule_timeout(signed long timeout);
323 extern signed long schedule_timeout_interruptible(signed long timeout);
324 extern signed long schedule_timeout_killable(signed long timeout);
325 extern signed long schedule_timeout_uninterruptible(signed long timeout);
326 asmlinkage void schedule(void);
327 extern void schedule_preempt_disabled(void);
328 extern int mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner);
329 
330 struct nsproxy;
331 struct user_namespace;
332 
333 /*
334  * Default maximum number of active map areas, this limits the number of vmas
335  * per mm struct. Users can overwrite this number by sysctl but there is a
336  * problem.
337  *
338  * When a program's coredump is generated as ELF format, a section is created
339  * per a vma. In ELF, the number of sections is represented in unsigned short.
340  * This means the number of sections should be smaller than 65535 at coredump.
341  * Because the kernel adds some informative sections to a image of program at
342  * generating coredump, we need some margin. The number of extra sections is
343  * 1-3 now and depends on arch. We use "5" as safe margin, here.
344  */
345 #define MAPCOUNT_ELF_CORE_MARGIN        (5)
346 #define DEFAULT_MAX_MAP_COUNT   (USHRT_MAX - MAPCOUNT_ELF_CORE_MARGIN)
347 
348 extern int sysctl_max_map_count;
349 
350 #include <linux/aio.h>
351 
352 #ifdef CONFIG_MMU
353 extern void arch_pick_mmap_layout(struct mm_struct *mm);
354 extern unsigned long
355 arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
356                        unsigned long, unsigned long);
357 extern unsigned long
358 arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
359                           unsigned long len, unsigned long pgoff,
360                           unsigned long flags);
361 extern void arch_unmap_area(struct mm_struct *, unsigned long);
362 extern void arch_unmap_area_topdown(struct mm_struct *, unsigned long);
363 #else
364 static inline void arch_pick_mmap_layout(struct mm_struct *mm) {}
365 #endif
366 
367 
368 extern void set_dumpable(struct mm_struct *mm, int value);
369 extern int get_dumpable(struct mm_struct *mm);
370 
371 /* get/set_dumpable() values */
372 #define SUID_DUMPABLE_DISABLED  0
373 #define SUID_DUMPABLE_ENABLED   1
374 #define SUID_DUMPABLE_SAFE      2
375 
376 /* mm flags */
377 /* dumpable bits */
378 #define MMF_DUMPABLE      0  /* core dump is permitted */
379 #define MMF_DUMP_SECURELY 1  /* core file is readable only by root */
380 
381 #define MMF_DUMPABLE_BITS 2
382 #define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
383 
384 /* coredump filter bits */
385 #define MMF_DUMP_ANON_PRIVATE   2
386 #define MMF_DUMP_ANON_SHARED    3
387 #define MMF_DUMP_MAPPED_PRIVATE 4
388 #define MMF_DUMP_MAPPED_SHARED  5
389 #define MMF_DUMP_ELF_HEADERS    6
390 #define MMF_DUMP_HUGETLB_PRIVATE 7
391 #define MMF_DUMP_HUGETLB_SHARED  8
392 
393 #define MMF_DUMP_FILTER_SHIFT   MMF_DUMPABLE_BITS
394 #define MMF_DUMP_FILTER_BITS    7
395 #define MMF_DUMP_FILTER_MASK \
396         (((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
397 #define MMF_DUMP_FILTER_DEFAULT \
398         ((1 << MMF_DUMP_ANON_PRIVATE) | (1 << MMF_DUMP_ANON_SHARED) |\
399          (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
400 
401 #ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
402 # define MMF_DUMP_MASK_DEFAULT_ELF      (1 << MMF_DUMP_ELF_HEADERS)
403 #else
404 # define MMF_DUMP_MASK_DEFAULT_ELF      0
405 #endif
406                                         /* leave room for more dump flags */
407 #define MMF_VM_MERGEABLE        16      /* KSM may merge identical pages */
408 #define MMF_VM_HUGEPAGE         17      /* set when VM_HUGEPAGE is set on vma */
409 #define MMF_EXE_FILE_CHANGED    18      /* see prctl_set_mm_exe_file() */
410 
411 #define MMF_HAS_UPROBES         19      /* has uprobes */
412 #define MMF_RECALC_UPROBES      20      /* MMF_HAS_UPROBES can be wrong */
413 
414 #define MMF_INIT_MASK           (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
415 
416 struct sighand_struct {
417         atomic_t                count;
418         struct k_sigaction      action[_NSIG];
419         spinlock_t              siglock;
420         wait_queue_head_t       signalfd_wqh;
421 };
422 
423 struct pacct_struct {
424         int                     ac_flag;
425         long                    ac_exitcode;
426         unsigned long           ac_mem;
427         cputime_t               ac_utime, ac_stime;
428         unsigned long           ac_minflt, ac_majflt;
429 };
430 
431 struct cpu_itimer {
432         cputime_t expires;
433         cputime_t incr;
434         u32 error;
435         u32 incr_error;
436 };
437 
438 /**
439  * struct task_cputime - collected CPU time counts
440  * @utime:              time spent in user mode, in &cputime_t units
441  * @stime:              time spent in kernel mode, in &cputime_t units
442  * @sum_exec_runtime:   total time spent on the CPU, in nanoseconds
443  *
444  * This structure groups together three kinds of CPU time that are
445  * tracked for threads and thread groups.  Most things considering
446  * CPU time want to group these counts together and treat all three
447  * of them in parallel.
448  */
449 struct task_cputime {
450         cputime_t utime;
451         cputime_t stime;
452         unsigned long long sum_exec_runtime;
453 };
454 /* Alternate field names when used to cache expirations. */
455 #define prof_exp        stime
456 #define virt_exp        utime
457 #define sched_exp       sum_exec_runtime
458 
459 #define INIT_CPUTIME    \
460         (struct task_cputime) {                                 \
461                 .utime = 0,                                     \
462                 .stime = 0,                                     \
463                 .sum_exec_runtime = 0,                          \
464         }
465 
466 /*
467  * Disable preemption until the scheduler is running.
468  * Reset by start_kernel()->sched_init()->init_idle().
469  *
470  * We include PREEMPT_ACTIVE to avoid cond_resched() from working
471  * before the scheduler is active -- see should_resched().
472  */
473 #define INIT_PREEMPT_COUNT      (1 + PREEMPT_ACTIVE)
474 
475 /**
476  * struct thread_group_cputimer - thread group interval timer counts
477  * @cputime:            thread group interval timers.
478  * @running:            non-zero when there are timers running and
479  *                      @cputime receives updates.
480  * @lock:               lock for fields in this struct.
481  *
482  * This structure contains the version of task_cputime, above, that is
483  * used for thread group CPU timer calculations.
484  */
485 struct thread_group_cputimer {
486         struct task_cputime cputime;
487         int running;
488         raw_spinlock_t lock;
489 };
490 
491 #include <linux/rwsem.h>
492 struct autogroup;
493 
494 /*
495  * NOTE! "signal_struct" does not have its own
496  * locking, because a shared signal_struct always
497  * implies a shared sighand_struct, so locking
498  * sighand_struct is always a proper superset of
499  * the locking of signal_struct.
500  */
501 struct signal_struct {
502         atomic_t                sigcnt;
503         atomic_t                live;
504         int                     nr_threads;
505 
506         wait_queue_head_t       wait_chldexit;  /* for wait4() */
507 
508         /* current thread group signal load-balancing target: */
509         struct task_struct      *curr_target;
510 
511         /* shared signal handling: */
512         struct sigpending       shared_pending;
513 
514         /* thread group exit support */
515         int                     group_exit_code;
516         /* overloaded:
517          * - notify group_exit_task when ->count is equal to notify_count
518          * - everyone except group_exit_task is stopped during signal delivery
519          *   of fatal signals, group_exit_task processes the signal.
520          */
521         int                     notify_count;
522         struct task_struct      *group_exit_task;
523 
524         /* thread group stop support, overloads group_exit_code too */
525         int                     group_stop_count;
526         unsigned int            flags; /* see SIGNAL_* flags below */
527 
528         /*
529          * PR_SET_CHILD_SUBREAPER marks a process, like a service
530          * manager, to re-parent orphan (double-forking) child processes
531          * to this process instead of 'init'. The service manager is
532          * able to receive SIGCHLD signals and is able to investigate
533          * the process until it calls wait(). All children of this
534          * process will inherit a flag if they should look for a
535          * child_subreaper process at exit.
536          */
537         unsigned int            is_child_subreaper:1;
538         unsigned int            has_child_subreaper:1;
539 
540         /* POSIX.1b Interval Timers */
541         struct list_head posix_timers;
542 
543         /* ITIMER_REAL timer for the process */
544         struct hrtimer real_timer;
545         struct pid *leader_pid;
546         ktime_t it_real_incr;
547 
548         /*
549          * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
550          * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
551          * values are defined to 0 and 1 respectively
552          */
553         struct cpu_itimer it[2];
554 
555         /*
556          * Thread group totals for process CPU timers.
557          * See thread_group_cputimer(), et al, for details.
558          */
559         struct thread_group_cputimer cputimer;
560 
561         /* Earliest-expiration cache. */
562         struct task_cputime cputime_expires;
563 
564         struct list_head cpu_timers[3];
565 
566         struct pid *tty_old_pgrp;
567 
568         /* boolean value for session group leader */
569         int leader;
570 
571         struct tty_struct *tty; /* NULL if no tty */
572 
573 #ifdef CONFIG_SCHED_AUTOGROUP
574         struct autogroup *autogroup;
575 #endif
576         /*
577          * Cumulative resource counters for dead threads in the group,
578          * and for reaped dead child processes forked by this group.
579          * Live threads maintain their own counters and add to these
580          * in __exit_signal, except for the group leader.
581          */
582         cputime_t utime, stime, cutime, cstime;
583         cputime_t gtime;
584         cputime_t cgtime;
585 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
586         cputime_t prev_utime, prev_stime;
587 #endif
588         unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
589         unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
590         unsigned long inblock, oublock, cinblock, coublock;
591         unsigned long maxrss, cmaxrss;
592         struct task_io_accounting ioac;
593 
594         /*
595          * Cumulative ns of schedule CPU time fo dead threads in the
596          * group, not including a zombie group leader, (This only differs
597          * from jiffies_to_ns(utime + stime) if sched_clock uses something
598          * other than jiffies.)
599          */
600         unsigned long long sum_sched_runtime;
601 
602         /*
603          * We don't bother to synchronize most readers of this at all,
604          * because there is no reader checking a limit that actually needs
605          * to get both rlim_cur and rlim_max atomically, and either one
606          * alone is a single word that can safely be read normally.
607          * getrlimit/setrlimit use task_lock(current->group_leader) to
608          * protect this instead of the siglock, because they really
609          * have no need to disable irqs.
610          */
611         struct rlimit rlim[RLIM_NLIMITS];
612 
613 #ifdef CONFIG_BSD_PROCESS_ACCT
614         struct pacct_struct pacct;      /* per-process accounting information */
615 #endif
616 #ifdef CONFIG_TASKSTATS
617         struct taskstats *stats;
618 #endif
619 #ifdef CONFIG_AUDIT
620         unsigned audit_tty;
621         struct tty_audit_buf *tty_audit_buf;
622 #endif
623 #ifdef CONFIG_CGROUPS
624         /*
625          * group_rwsem prevents new tasks from entering the threadgroup and
626          * member tasks from exiting,a more specifically, setting of
627          * PF_EXITING.  fork and exit paths are protected with this rwsem
628          * using threadgroup_change_begin/end().  Users which require
629          * threadgroup to remain stable should use threadgroup_[un]lock()
630          * which also takes care of exec path.  Currently, cgroup is the
631          * only user.
632          */
633         struct rw_semaphore group_rwsem;
634 #endif
635 
636         int oom_score_adj;      /* OOM kill score adjustment */
637         int oom_score_adj_min;  /* OOM kill score adjustment minimum value.
638                                  * Only settable by CAP_SYS_RESOURCE. */
639 
640         struct mutex cred_guard_mutex;  /* guard against foreign influences on
641                                          * credential calculations
642                                          * (notably. ptrace) */
643 };
644 
645 /*
646  * Bits in flags field of signal_struct.
647  */
648 #define SIGNAL_STOP_STOPPED     0x00000001 /* job control stop in effect */
649 #define SIGNAL_STOP_CONTINUED   0x00000002 /* SIGCONT since WCONTINUED reap */
650 #define SIGNAL_GROUP_EXIT       0x00000004 /* group exit in progress */
651 /*
652  * Pending notifications to parent.
653  */
654 #define SIGNAL_CLD_STOPPED      0x00000010
655 #define SIGNAL_CLD_CONTINUED    0x00000020
656 #define SIGNAL_CLD_MASK         (SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
657 
658 #define SIGNAL_UNKILLABLE       0x00000040 /* for init: ignore fatal signals */
659 
660 /* If true, all threads except ->group_exit_task have pending SIGKILL */
661 static inline int signal_group_exit(const struct signal_struct *sig)
662 {
663         return  (sig->flags & SIGNAL_GROUP_EXIT) ||
664                 (sig->group_exit_task != NULL);
665 }
666 
667 /*
668  * Some day this will be a full-fledged user tracking system..
669  */
670 struct user_struct {
671         atomic_t __count;       /* reference count */
672         atomic_t processes;     /* How many processes does this user have? */
673         atomic_t files;         /* How many open files does this user have? */
674         atomic_t sigpending;    /* How many pending signals does this user have? */
675 #ifdef CONFIG_INOTIFY_USER
676         atomic_t inotify_watches; /* How many inotify watches does this user have? */
677         atomic_t inotify_devs;  /* How many inotify devs does this user have opened? */
678 #endif
679 #ifdef CONFIG_FANOTIFY
680         atomic_t fanotify_listeners;
681 #endif
682 #ifdef CONFIG_EPOLL
683         atomic_long_t epoll_watches; /* The number of file descriptors currently watched */
684 #endif
685 #ifdef CONFIG_POSIX_MQUEUE
686         /* protected by mq_lock */
687         unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */
688 #endif
689         unsigned long locked_shm; /* How many pages of mlocked shm ? */
690 
691 #ifdef CONFIG_KEYS
692         struct key *uid_keyring;        /* UID specific keyring */
693         struct key *session_keyring;    /* UID's default session keyring */
694 #endif
695 
696         /* Hash table maintenance information */
697         struct hlist_node uidhash_node;
698         kuid_t uid;
699 
700 #ifdef CONFIG_PERF_EVENTS
701         atomic_long_t locked_vm;
702 #endif
703 };
704 
705 extern int uids_sysfs_init(void);
706 
707 extern struct user_struct *find_user(kuid_t);
708 
709 extern struct user_struct root_user;
710 #define INIT_USER (&root_user)
711 
712 
713 struct backing_dev_info;
714 struct reclaim_state;
715 
716 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
717 struct sched_info {
718         /* cumulative counters */
719         unsigned long pcount;         /* # of times run on this cpu */
720         unsigned long long run_delay; /* time spent waiting on a runqueue */
721 
722         /* timestamps */
723         unsigned long long last_arrival,/* when we last ran on a cpu */
724                            last_queued; /* when we were last queued to run */
725 };
726 #endif /* defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) */
727 
728 #ifdef CONFIG_TASK_DELAY_ACCT
729 struct task_delay_info {
730         spinlock_t      lock;
731         unsigned int    flags;  /* Private per-task flags */
732 
733         /* For each stat XXX, add following, aligned appropriately
734          *
735          * struct timespec XXX_start, XXX_end;
736          * u64 XXX_delay;
737          * u32 XXX_count;
738          *
739          * Atomicity of updates to XXX_delay, XXX_count protected by
740          * single lock above (split into XXX_lock if contention is an issue).
741          */
742 
743         /*
744          * XXX_count is incremented on every XXX operation, the delay
745          * associated with the operation is added to XXX_delay.
746          * XXX_delay contains the accumulated delay time in nanoseconds.
747          */
748         struct timespec blkio_start, blkio_end; /* Shared by blkio, swapin */
749         u64 blkio_delay;        /* wait for sync block io completion */
750         u64 swapin_delay;       /* wait for swapin block io completion */
751         u32 blkio_count;        /* total count of the number of sync block */
752                                 /* io operations performed */
753         u32 swapin_count;       /* total count of the number of swapin block */
754                                 /* io operations performed */
755 
756         struct timespec freepages_start, freepages_end;
757         u64 freepages_delay;    /* wait for memory reclaim */
758         u32 freepages_count;    /* total count of memory reclaim */
759 };
760 #endif  /* CONFIG_TASK_DELAY_ACCT */
761 
762 static inline int sched_info_on(void)
763 {
764 #ifdef CONFIG_SCHEDSTATS
765         return 1;
766 #elif defined(CONFIG_TASK_DELAY_ACCT)
767         extern int delayacct_on;
768         return delayacct_on;
769 #else
770         return 0;
771 #endif
772 }
773 
774 enum cpu_idle_type {
775         CPU_IDLE,
776         CPU_NOT_IDLE,
777         CPU_NEWLY_IDLE,
778         CPU_MAX_IDLE_TYPES
779 };
780 
781 /*
782  * Increase resolution of nice-level calculations for 64-bit architectures.
783  * The extra resolution improves shares distribution and load balancing of
784  * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup
785  * hierarchies, especially on larger systems. This is not a user-visible change
786  * and does not change the user-interface for setting shares/weights.
787  *
788  * We increase resolution only if we have enough bits to allow this increased
789  * resolution (i.e. BITS_PER_LONG > 32). The costs for increasing resolution
790  * when BITS_PER_LONG <= 32 are pretty high and the returns do not justify the
791  * increased costs.
792  */
793 #if 0 /* BITS_PER_LONG > 32 -- currently broken: it increases power usage under light load  */
794 # define SCHED_LOAD_RESOLUTION  10
795 # define scale_load(w)          ((w) << SCHED_LOAD_RESOLUTION)
796 # define scale_load_down(w)     ((w) >> SCHED_LOAD_RESOLUTION)
797 #else
798 # define SCHED_LOAD_RESOLUTION  0
799 # define scale_load(w)          (w)
800 # define scale_load_down(w)     (w)
801 #endif
802 
803 #define SCHED_LOAD_SHIFT        (10 + SCHED_LOAD_RESOLUTION)
804 #define SCHED_LOAD_SCALE        (1L << SCHED_LOAD_SHIFT)
805 
806 /*
807  * Increase resolution of cpu_power calculations
808  */
809 #define SCHED_POWER_SHIFT       10
810 #define SCHED_POWER_SCALE       (1L << SCHED_POWER_SHIFT)
811 
812 /*
813  * sched-domains (multiprocessor balancing) declarations:
814  */
815 #ifdef CONFIG_SMP
816 #define SD_LOAD_BALANCE         0x0001  /* Do load balancing on this domain. */
817 #define SD_BALANCE_NEWIDLE      0x0002  /* Balance when about to become idle */
818 #define SD_BALANCE_EXEC         0x0004  /* Balance on exec */
819 #define SD_BALANCE_FORK         0x0008  /* Balance on fork, clone */
820 #define SD_BALANCE_WAKE         0x0010  /* Balance on wakeup */
821 #define SD_WAKE_AFFINE          0x0020  /* Wake task to waking CPU */
822 #define SD_SHARE_CPUPOWER       0x0080  /* Domain members share cpu power */
823 #define SD_SHARE_PKG_RESOURCES  0x0200  /* Domain members share cpu pkg resources */
824 #define SD_SERIALIZE            0x0400  /* Only a single load balancing instance */
825 #define SD_ASYM_PACKING         0x0800  /* Place busy groups earlier in the domain */
826 #define SD_PREFER_SIBLING       0x1000  /* Prefer to place tasks in a sibling domain */
827 #define SD_OVERLAP              0x2000  /* sched_domains of this level overlap */
828 
829 extern int __weak arch_sd_sibiling_asym_packing(void);
830 
831 struct sched_group_power {
832         atomic_t ref;
833         /*
834          * CPU power of this group, SCHED_LOAD_SCALE being max power for a
835          * single CPU.
836          */
837         unsigned int power, power_orig;
838         unsigned long next_update;
839         /*
840          * Number of busy cpus in this group.
841          */
842         atomic_t nr_busy_cpus;
843 
844         unsigned long cpumask[0]; /* iteration mask */
845 };
846 
847 struct sched_group {
848         struct sched_group *next;       /* Must be a circular list */
849         atomic_t ref;
850 
851         unsigned int group_weight;
852         struct sched_group_power *sgp;
853 
854         /*
855          * The CPUs this group covers.
856          *
857          * NOTE: this field is variable length. (Allocated dynamically
858          * by attaching extra space to the end of the structure,
859          * depending on how many CPUs the kernel has booted up with)
860          */
861         unsigned long cpumask[0];
862 };
863 
864 static inline struct cpumask *sched_group_cpus(struct sched_group *sg)
865 {
866         return to_cpumask(sg->cpumask);
867 }
868 
869 /*
870  * cpumask masking which cpus in the group are allowed to iterate up the domain
871  * tree.
872  */
873 static inline struct cpumask *sched_group_mask(struct sched_group *sg)
874 {
875         return to_cpumask(sg->sgp->cpumask);
876 }
877 
878 /**
879  * group_first_cpu - Returns the first cpu in the cpumask of a sched_group.
880  * @group: The group whose first cpu is to be returned.
881  */
882 static inline unsigned int group_first_cpu(struct sched_group *group)
883 {
884         return cpumask_first(sched_group_cpus(group));
885 }
886 
887 struct sched_domain_attr {
888         int relax_domain_level;
889 };
890 
891 #define SD_ATTR_INIT    (struct sched_domain_attr) {    \
892         .relax_domain_level = -1,                       \
893 }
894 
895 extern int sched_domain_level_max;
896 
897 struct sched_domain {
898         /* These fields must be setup */
899         struct sched_domain *parent;    /* top domain must be null terminated */
900         struct sched_domain *child;     /* bottom domain must be null terminated */
901         struct sched_group *groups;     /* the balancing groups of the domain */
902         unsigned long min_interval;     /* Minimum balance interval ms */
903         unsigned long max_interval;     /* Maximum balance interval ms */
904         unsigned int busy_factor;       /* less balancing by factor if busy */
905         unsigned int imbalance_pct;     /* No balance until over watermark */
906         unsigned int cache_nice_tries;  /* Leave cache hot tasks for # tries */
907         unsigned int busy_idx;
908         unsigned int idle_idx;
909         unsigned int newidle_idx;
910         unsigned int wake_idx;
911         unsigned int forkexec_idx;
912         unsigned int smt_gain;
913         int flags;                      /* See SD_* */
914         int level;
915 
916         /* Runtime fields. */
917         unsigned long last_balance;     /* init to jiffies. units in jiffies */
918         unsigned int balance_interval;  /* initialise to 1. units in ms. */
919         unsigned int nr_balance_failed; /* initialise to 0 */
920 
921         u64 last_update;
922 
923 #ifdef CONFIG_SCHEDSTATS
924         /* load_balance() stats */
925         unsigned int lb_count[CPU_MAX_IDLE_TYPES];
926         unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
927         unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
928         unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
929         unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
930         unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
931         unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
932         unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
933 
934         /* Active load balancing */
935         unsigned int alb_count;
936         unsigned int alb_failed;
937         unsigned int alb_pushed;
938 
939         /* SD_BALANCE_EXEC stats */
940         unsigned int sbe_count;
941         unsigned int sbe_balanced;
942         unsigned int sbe_pushed;
943 
944         /* SD_BALANCE_FORK stats */
945         unsigned int sbf_count;
946         unsigned int sbf_balanced;
947         unsigned int sbf_pushed;
948 
949         /* try_to_wake_up() stats */
950         unsigned int ttwu_wake_remote;
951         unsigned int ttwu_move_affine;
952         unsigned int ttwu_move_balance;
953 #endif
954 #ifdef CONFIG_SCHED_DEBUG
955         char *name;
956 #endif
957         union {
958                 void *private;          /* used during construction */
959                 struct rcu_head rcu;    /* used during destruction */
960         };
961 
962         unsigned int span_weight;
963         /*
964          * Span of all CPUs in this domain.
965          *
966          * NOTE: this field is variable length. (Allocated dynamically
967          * by attaching extra space to the end of the structure,
968          * depending on how many CPUs the kernel has booted up with)
969          */
970         unsigned long span[0];
971 };
972 
973 static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
974 {
975         return to_cpumask(sd->span);
976 }
977 
978 extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
979                                     struct sched_domain_attr *dattr_new);
980 
981 /* Allocate an array of sched domains, for partition_sched_domains(). */
982 cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
983 void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
984 
985 /* Test a flag in parent sched domain */
986 static inline int test_sd_parent(struct sched_domain *sd, int flag)
987 {
988         if (sd->parent && (sd->parent->flags & flag))
989                 return 1;
990 
991         return 0;
992 }
993 
994 unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu);
995 unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu);
996 
997 bool cpus_share_cache(int this_cpu, int that_cpu);
998 
999 #else /* CONFIG_SMP */
1000 
1001 struct sched_domain_attr;
1002 
1003 static inline void
1004 partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1005                         struct sched_domain_attr *dattr_new)
1006 {
1007 }
1008 
1009 static inline bool cpus_share_cache(int this_cpu, int that_cpu)
1010 {
1011         return true;
1012 }
1013 
1014 #endif  /* !CONFIG_SMP */
1015 
1016 
1017 struct io_context;                      /* See blkdev.h */
1018 
1019 
1020 #ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
1021 extern void prefetch_stack(struct task_struct *t);
1022 #else
1023 static inline void prefetch_stack(struct task_struct *t) { }
1024 #endif
1025 
1026 struct audit_context;           /* See audit.c */
1027 struct mempolicy;
1028 struct pipe_inode_info;
1029 struct uts_namespace;
1030 
1031 struct rq;
1032 struct sched_domain;
1033 
1034 /*
1035  * wake flags
1036  */
1037 #define WF_SYNC         0x01            /* waker goes to sleep after wakup */
1038 #define WF_FORK         0x02            /* child wakeup after fork */
1039 #define WF_MIGRATED     0x04            /* internal use, task got migrated */
1040 
1041 #define ENQUEUE_WAKEUP          1
1042 #define ENQUEUE_HEAD            2
1043 #ifdef CONFIG_SMP
1044 #define ENQUEUE_WAKING          4       /* sched_class::task_waking was called */
1045 #else
1046 #define ENQUEUE_WAKING          0
1047 #endif
1048 
1049 #define DEQUEUE_SLEEP           1
1050 
1051 struct sched_class {
1052         const struct sched_class *next;
1053 
1054         void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags);
1055         void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags);
1056         void (*yield_task) (struct rq *rq);
1057         bool (*yield_to_task) (struct rq *rq, struct task_struct *p, bool preempt);
1058 
1059         void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags);
1060 
1061         struct task_struct * (*pick_next_task) (struct rq *rq);
1062         void (*put_prev_task) (struct rq *rq, struct task_struct *p);
1063 
1064 #ifdef CONFIG_SMP
1065         int  (*select_task_rq)(struct task_struct *p, int sd_flag, int flags);
1066 
1067         void (*pre_schedule) (struct rq *this_rq, struct task_struct *task);
1068         void (*post_schedule) (struct rq *this_rq);
1069         void (*task_waking) (struct task_struct *task);
1070         void (*task_woken) (struct rq *this_rq, struct task_struct *task);
1071 
1072         void (*set_cpus_allowed)(struct task_struct *p,
1073                                  const struct cpumask *newmask);
1074 
1075         void (*rq_online)(struct rq *rq);
1076         void (*rq_offline)(struct rq *rq);
1077 #endif
1078 
1079         void (*set_curr_task) (struct rq *rq);
1080         void (*task_tick) (struct rq *rq, struct task_struct *p, int queued);
1081         void (*task_fork) (struct task_struct *p);
1082 
1083         void (*switched_from) (struct rq *this_rq, struct task_struct *task);
1084         void (*switched_to) (struct rq *this_rq, struct task_struct *task);
1085         void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
1086                              int oldprio);
1087 
1088         unsigned int (*get_rr_interval) (struct rq *rq,
1089                                          struct task_struct *task);
1090 
1091 #ifdef CONFIG_FAIR_GROUP_SCHED
1092         void (*task_move_group) (struct task_struct *p, int on_rq);
1093 #endif
1094 };
1095 
1096 struct load_weight {
1097         unsigned long weight, inv_weight;
1098 };
1099 
1100 #ifdef CONFIG_SCHEDSTATS
1101 struct sched_statistics {
1102         u64                     wait_start;
1103         u64                     wait_max;
1104         u64                     wait_count;
1105         u64                     wait_sum;
1106         u64                     iowait_count;
1107         u64                     iowait_sum;
1108 
1109         u64                     sleep_start;
1110         u64                     sleep_max;
1111         s64                     sum_sleep_runtime;
1112 
1113         u64                     block_start;
1114         u64                     block_max;
1115         u64                     exec_max;
1116         u64                     slice_max;
1117 
1118         u64                     nr_migrations_cold;
1119         u64                     nr_failed_migrations_affine;
1120         u64                     nr_failed_migrations_running;
1121         u64                     nr_failed_migrations_hot;
1122         u64                     nr_forced_migrations;
1123 
1124         u64                     nr_wakeups;
1125         u64                     nr_wakeups_sync;
1126         u64                     nr_wakeups_migrate;
1127         u64                     nr_wakeups_local;
1128         u64                     nr_wakeups_remote;
1129         u64                     nr_wakeups_affine;
1130         u64                     nr_wakeups_affine_attempts;
1131         u64                     nr_wakeups_passive;
1132         u64                     nr_wakeups_idle;
1133 };
1134 #endif
1135 
1136 struct sched_entity {
1137         struct load_weight      load;           /* for load-balancing */
1138         struct rb_node          run_node;
1139         struct list_head        group_node;
1140         unsigned int            on_rq;
1141 
1142         u64                     exec_start;
1143         u64                     sum_exec_runtime;
1144         u64                     vruntime;
1145         u64                     prev_sum_exec_runtime;
1146 
1147         u64                     nr_migrations;
1148 
1149 #ifdef CONFIG_SCHEDSTATS
1150         struct sched_statistics statistics;
1151 #endif
1152 
1153 #ifdef CONFIG_FAIR_GROUP_SCHED
1154         struct sched_entity     *parent;
1155         /* rq on which this entity is (to be) queued: */
1156         struct cfs_rq           *cfs_rq;
1157         /* rq "owned" by this entity/group: */
1158         struct cfs_rq           *my_q;
1159 #endif
1160 };
1161 
1162 struct sched_rt_entity {
1163         struct list_head run_list;
1164         unsigned long timeout;
1165         unsigned int time_slice;
1166 
1167         struct sched_rt_entity *back;
1168 #ifdef CONFIG_RT_GROUP_SCHED
1169         struct sched_rt_entity  *parent;
1170         /* rq on which this entity is (to be) queued: */
1171         struct rt_rq            *rt_rq;
1172         /* rq "owned" by this entity/group: */
1173         struct rt_rq            *my_q;
1174 #endif
1175 };
1176 
1177 /*
1178  * default timeslice is 100 msecs (used only for SCHED_RR tasks).
1179  * Timeslices get refilled after they expire.
1180  */
1181 #define RR_TIMESLICE            (100 * HZ / 1000)
1182 
1183 struct rcu_node;
1184 
1185 enum perf_event_task_context {
1186         perf_invalid_context = -1,
1187         perf_hw_context = 0,
1188         perf_sw_context,
1189         perf_nr_task_contexts,
1190 };
1191 
1192 struct task_struct {
1193         volatile long state;    /* -1 unrunnable, 0 runnable, >0 stopped */
1194         void *stack;
1195         atomic_t usage;
1196         unsigned int flags;     /* per process flags, defined below */
1197         unsigned int ptrace;
1198 
1199 #ifdef CONFIG_SMP
1200         struct llist_node wake_entry;
1201         int on_cpu;
1202 #endif
1203         int on_rq;
1204 
1205         int prio, static_prio, normal_prio;
1206         unsigned int rt_priority;
1207         const struct sched_class *sched_class;
1208         struct sched_entity se;
1209         struct sched_rt_entity rt;
1210 #ifdef CONFIG_CGROUP_SCHED
1211         struct task_group *sched_task_group;
1212 #endif
1213 
1214 #ifdef CONFIG_PREEMPT_NOTIFIERS
1215         /* list of struct preempt_notifier: */
1216         struct hlist_head preempt_notifiers;
1217 #endif
1218 
1219         /*
1220          * fpu_counter contains the number of consecutive context switches
1221          * that the FPU is used. If this is over a threshold, the lazy fpu
1222          * saving becomes unlazy to save the trap. This is an unsigned char
1223          * so that after 256 times the counter wraps and the behavior turns
1224          * lazy again; this to deal with bursty apps that only use FPU for
1225          * a short time
1226          */
1227         unsigned char fpu_counter;
1228 #ifdef CONFIG_BLK_DEV_IO_TRACE
1229         unsigned int btrace_seq;
1230 #endif
1231 
1232         unsigned int policy;
1233         int nr_cpus_allowed;
1234         cpumask_t cpus_allowed;
1235 
1236 #ifdef CONFIG_PREEMPT_RCU
1237         int rcu_read_lock_nesting;
1238         char rcu_read_unlock_special;
1239         struct list_head rcu_node_entry;
1240 #endif /* #ifdef CONFIG_PREEMPT_RCU */
1241 #ifdef CONFIG_TREE_PREEMPT_RCU
1242         struct rcu_node *rcu_blocked_node;
1243 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
1244 #ifdef CONFIG_RCU_BOOST
1245         struct rt_mutex *rcu_boost_mutex;
1246 #endif /* #ifdef CONFIG_RCU_BOOST */
1247 
1248 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
1249         struct sched_info sched_info;
1250 #endif
1251 
1252         struct list_head tasks;
1253 #ifdef CONFIG_SMP
1254         struct plist_node pushable_tasks;
1255 #endif
1256 
1257         struct mm_struct *mm, *active_mm;
1258 #ifdef CONFIG_COMPAT_BRK
1259         unsigned brk_randomized:1;
1260 #endif
1261 #if defined(SPLIT_RSS_COUNTING)
1262         struct task_rss_stat    rss_stat;
1263 #endif
1264 /* task state */
1265         int exit_state;
1266         int exit_code, exit_signal;
1267         int pdeath_signal;  /*  The signal sent when the parent dies  */
1268         unsigned int jobctl;    /* JOBCTL_*, siglock protected */
1269         /* ??? */
1270         unsigned int personality;
1271         unsigned did_exec:1;
1272         unsigned in_execve:1;   /* Tell the LSMs that the process is doing an
1273                                  * execve */
1274         unsigned in_iowait:1;
1275 
1276         /* task may not gain privileges */
1277         unsigned no_new_privs:1;
1278 
1279         /* Revert to default priority/policy when forking */
1280         unsigned sched_reset_on_fork:1;
1281         unsigned sched_contributes_to_load:1;
1282 
1283         pid_t pid;
1284         pid_t tgid;
1285 
1286 #ifdef CONFIG_CC_STACKPROTECTOR
1287         /* Canary value for the -fstack-protector gcc feature */
1288         unsigned long stack_canary;
1289 #endif
1290         /*
1291          * pointers to (original) parent process, youngest child, younger sibling,
1292          * older sibling, respectively.  (p->father can be replaced with
1293          * p->real_parent->pid)
1294          */
1295         struct task_struct __rcu *real_parent; /* real parent process */
1296         struct task_struct __rcu *parent; /* recipient of SIGCHLD, wait4() reports */
1297         /*
1298          * children/sibling forms the list of my natural children
1299          */
1300         struct list_head children;      /* list of my children */
1301         struct list_head sibling;       /* linkage in my parent's children list */
1302         struct task_struct *group_leader;       /* threadgroup leader */
1303 
1304         /*
1305          * ptraced is the list of tasks this task is using ptrace on.
1306          * This includes both natural children and PTRACE_ATTACH targets.
1307          * p->ptrace_entry is p's link on the p->parent->ptraced list.
1308          */
1309         struct list_head ptraced;
1310         struct list_head ptrace_entry;
1311 
1312         /* PID/PID hash table linkage. */
1313         struct pid_link pids[PIDTYPE_MAX];
1314         struct list_head thread_group;
1315 
1316         struct completion *vfork_done;          /* for vfork() */
1317         int __user *set_child_tid;              /* CLONE_CHILD_SETTID */
1318         int __user *clear_child_tid;            /* CLONE_CHILD_CLEARTID */
1319 
1320         cputime_t utime, stime, utimescaled, stimescaled;
1321         cputime_t gtime;
1322 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
1323         cputime_t prev_utime, prev_stime;
1324 #endif
1325         unsigned long nvcsw, nivcsw; /* context switch counts */
1326         struct timespec start_time;             /* monotonic time */
1327         struct timespec real_start_time;        /* boot based time */
1328 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1329         unsigned long min_flt, maj_flt;
1330 
1331         struct task_cputime cputime_expires;
1332         struct list_head cpu_timers[3];
1333 
1334 /* process credentials */
1335         const struct cred __rcu *real_cred; /* objective and real subjective task
1336                                          * credentials (COW) */
1337         const struct cred __rcu *cred;  /* effective (overridable) subjective task
1338                                          * credentials (COW) */
1339         char comm[TASK_COMM_LEN]; /* executable name excluding path
1340                                      - access with [gs]et_task_comm (which lock
1341                                        it with task_lock())
1342                                      - initialized normally by setup_new_exec */
1343 /* file system info */
1344         int link_count, total_link_count;
1345 #ifdef CONFIG_SYSVIPC
1346 /* ipc stuff */
1347         struct sysv_sem sysvsem;
1348 #endif
1349 #ifdef CONFIG_DETECT_HUNG_TASK
1350 /* hung task detection */
1351         unsigned long last_switch_count;
1352 #endif
1353 /* CPU-specific state of this task */
1354         struct thread_struct thread;
1355 /* filesystem information */
1356         struct fs_struct *fs;
1357 /* open file information */
1358         struct files_struct *files;
1359 /* namespaces */
1360         struct nsproxy *nsproxy;
1361 /* signal handlers */
1362         struct signal_struct *signal;
1363         struct sighand_struct *sighand;
1364 
1365         sigset_t blocked, real_blocked;
1366         sigset_t saved_sigmask; /* restored if set_restore_sigmask() was used */
1367         struct sigpending pending;
1368 
1369         unsigned long sas_ss_sp;
1370         size_t sas_ss_size;
1371         int (*notifier)(void *priv);
1372         void *notifier_data;
1373         sigset_t *notifier_mask;
1374         struct callback_head *task_works;
1375 
1376         struct audit_context *audit_context;
1377 #ifdef CONFIG_AUDITSYSCALL
1378         kuid_t loginuid;
1379         unsigned int sessionid;
1380 #endif
1381         struct seccomp seccomp;
1382 
1383 /* Thread group tracking */
1384         u32 parent_exec_id;
1385         u32 self_exec_id;
1386 /* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1387  * mempolicy */
1388         spinlock_t alloc_lock;
1389 
1390         /* Protection of the PI data structures: */
1391         raw_spinlock_t pi_lock;
1392 
1393 #ifdef CONFIG_RT_MUTEXES
1394         /* PI waiters blocked on a rt_mutex held by this task */
1395         struct plist_head pi_waiters;
1396         /* Deadlock detection and priority inheritance handling */
1397         struct rt_mutex_waiter *pi_blocked_on;
1398 #endif
1399 
1400 #ifdef CONFIG_DEBUG_MUTEXES
1401         /* mutex deadlock detection */
1402         struct mutex_waiter *blocked_on;
1403 #endif
1404 #ifdef CONFIG_TRACE_IRQFLAGS
1405         unsigned int irq_events;
1406         unsigned long hardirq_enable_ip;
1407         unsigned long hardirq_disable_ip;
1408         unsigned int hardirq_enable_event;
1409         unsigned int hardirq_disable_event;
1410         int hardirqs_enabled;
1411         int hardirq_context;
1412         unsigned long softirq_disable_ip;
1413         unsigned long softirq_enable_ip;
1414         unsigned int softirq_disable_event;
1415         unsigned int softirq_enable_event;
1416         int softirqs_enabled;
1417         int softirq_context;
1418 #endif
1419 #ifdef CONFIG_LOCKDEP
1420 # define MAX_LOCK_DEPTH 48UL
1421         u64 curr_chain_key;
1422         int lockdep_depth;
1423         unsigned int lockdep_recursion;
1424         struct held_lock held_locks[MAX_LOCK_DEPTH];
1425         gfp_t lockdep_reclaim_gfp;
1426 #endif
1427 
1428 /* journalling filesystem info */
1429         void *journal_info;
1430 
1431 /* stacked block device info */
1432         struct bio_list *bio_list;
1433 
1434 #ifdef CONFIG_BLOCK
1435 /* stack plugging */
1436         struct blk_plug *plug;
1437 #endif
1438 
1439 /* VM state */
1440         struct reclaim_state *reclaim_state;
1441 
1442         struct backing_dev_info *backing_dev_info;
1443 
1444         struct io_context *io_context;
1445 
1446         unsigned long ptrace_message;
1447         siginfo_t *last_siginfo; /* For ptrace use.  */
1448         struct task_io_accounting ioac;
1449 #if defined(CONFIG_TASK_XACCT)
1450         u64 acct_rss_mem1;      /* accumulated rss usage */
1451         u64 acct_vm_mem1;       /* accumulated virtual memory usage */
1452         cputime_t acct_timexpd; /* stime + utime since last update */
1453 #endif
1454 #ifdef CONFIG_CPUSETS
1455         nodemask_t mems_allowed;        /* Protected by alloc_lock */
1456         seqcount_t mems_allowed_seq;    /* Seqence no to catch updates */
1457         int cpuset_mem_spread_rotor;
1458         int cpuset_slab_spread_rotor;
1459 #endif
1460 #ifdef CONFIG_CGROUPS
1461         /* Control Group info protected by css_set_lock */
1462         struct css_set __rcu *cgroups;
1463         /* cg_list protected by css_set_lock and tsk->alloc_lock */
1464         struct list_head cg_list;
1465 #endif
1466 #ifdef CONFIG_FUTEX
1467         struct robust_list_head __user *robust_list;
1468 #ifdef CONFIG_COMPAT
1469         struct compat_robust_list_head __user *compat_robust_list;
1470 #endif
1471         struct list_head pi_state_list;
1472         struct futex_pi_state *pi_state_cache;
1473 #endif
1474 #ifdef CONFIG_PERF_EVENTS
1475         struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1476         struct mutex perf_event_mutex;
1477         struct list_head perf_event_list;
1478 #endif
1479 #ifdef CONFIG_NUMA
1480         struct mempolicy *mempolicy;    /* Protected by alloc_lock */
1481         short il_next;
1482         short pref_node_fork;
1483 #endif
1484         struct rcu_head rcu;
1485 
1486         /*
1487          * cache last used pipe for splice
1488          */
1489         struct pipe_inode_info *splice_pipe;
1490 
1491         struct page_frag task_frag;
1492 
1493 #ifdef  CONFIG_TASK_DELAY_ACCT
1494         struct task_delay_info *delays;
1495 #endif
1496 #ifdef CONFIG_FAULT_INJECTION
1497         int make_it_fail;
1498 #endif
1499         /*
1500          * when (nr_dirtied >= nr_dirtied_pause), it's time to call
1501          * balance_dirty_pages() for some dirty throttling pause
1502          */
1503         int nr_dirtied;
1504         int nr_dirtied_pause;
1505         unsigned long dirty_paused_when; /* start of a write-and-pause period */
1506 
1507 #ifdef CONFIG_LATENCYTOP
1508         int latency_record_count;
1509         struct latency_record latency_record[LT_SAVECOUNT];
1510 #endif
1511         /*
1512          * time slack values; these are used to round up poll() and
1513          * select() etc timeout values. These are in nanoseconds.
1514          */
1515         unsigned long timer_slack_ns;
1516         unsigned long default_timer_slack_ns;
1517 
1518 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1519         /* Index of current stored address in ret_stack */
1520         int curr_ret_stack;
1521         /* Stack of return addresses for return function tracing */
1522         struct ftrace_ret_stack *ret_stack;
1523         /* time stamp for last schedule */
1524         unsigned long long ftrace_timestamp;
1525         /*
1526          * Number of functions that haven't been traced
1527          * because of depth overrun.
1528          */
1529         atomic_t trace_overrun;
1530         /* Pause for the tracing */
1531         atomic_t tracing_graph_pause;
1532 #endif
1533 #ifdef CONFIG_TRACING
1534         /* state flags for use by tracers */
1535         unsigned long trace;
1536         /* bitmask and counter of trace recursion */
1537         unsigned long trace_recursion;
1538 #endif /* CONFIG_TRACING */
1539 #ifdef CONFIG_MEMCG /* memcg uses this to do batch job */
1540         struct memcg_batch_info {
1541                 int do_batch;   /* incremented when batch uncharge started */
1542                 struct mem_cgroup *memcg; /* target memcg of uncharge */
1543                 unsigned long nr_pages; /* uncharged usage */
1544                 unsigned long memsw_nr_pages; /* uncharged mem+swap usage */
1545         } memcg_batch;
1546 #endif
1547 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1548         atomic_t ptrace_bp_refcnt;
1549 #endif
1550 #ifdef CONFIG_UPROBES
1551         struct uprobe_task *utask;
1552 #endif
1553 #if defined(CONFIG_CCSECURITY) && !defined(CONFIG_CCSECURITY_USE_EXTERNAL_TASK_SECURITY)
1554         struct ccs_domain_info *ccs_domain_info;
1555         u32 ccs_flags;
1556 #endif
1557 };
1558 
1559 /* Future-safe accessor for struct task_struct's cpus_allowed. */
1560 #define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
1561 
1562 /*
1563  * Priority of a process goes from 0..MAX_PRIO-1, valid RT
1564  * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
1565  * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority
1566  * values are inverted: lower p->prio value means higher priority.
1567  *
1568  * The MAX_USER_RT_PRIO value allows the actual maximum
1569  * RT priority to be separate from the value exported to
1570  * user-space.  This allows kernel threads to set their
1571  * priority to a value higher than any user task. Note:
1572  * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
1573  */
1574 
1575 #define MAX_USER_RT_PRIO        100
1576 #define MAX_RT_PRIO             MAX_USER_RT_PRIO
1577 
1578 #define MAX_PRIO                (MAX_RT_PRIO + 40)
1579 #define DEFAULT_PRIO            (MAX_RT_PRIO + 20)
1580 
1581 static inline int rt_prio(int prio)
1582 {
1583         if (unlikely(prio < MAX_RT_PRIO))
1584                 return 1;
1585         return 0;
1586 }
1587 
1588 static inline int rt_task(struct task_struct *p)
1589 {
1590         return rt_prio(p->prio);
1591 }
1592 
1593 static inline struct pid *task_pid(struct task_struct *task)
1594 {
1595         return task->pids[PIDTYPE_PID].pid;
1596 }
1597 
1598 static inline struct pid *task_tgid(struct task_struct *task)
1599 {
1600         return task->group_leader->pids[PIDTYPE_PID].pid;
1601 }
1602 
1603 /*
1604  * Without tasklist or rcu lock it is not safe to dereference
1605  * the result of task_pgrp/task_session even if task == current,
1606  * we can race with another thread doing sys_setsid/sys_setpgid.
1607  */
1608 static inline struct pid *task_pgrp(struct task_struct *task)
1609 {
1610         return task->group_leader->pids[PIDTYPE_PGID].pid;
1611 }
1612 
1613 static inline struct pid *task_session(struct task_struct *task)
1614 {
1615         return task->group_leader->pids[PIDTYPE_SID].pid;
1616 }
1617 
1618 struct pid_namespace;
1619 
1620 /*
1621  * the helpers to get the task's different pids as they are seen
1622  * from various namespaces
1623  *
1624  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1625  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1626  *                     current.
1627  * task_xid_nr_ns()  : id seen from the ns specified;
1628  *
1629  * set_task_vxid()   : assigns a virtual id to a task;
1630  *
1631  * see also pid_nr() etc in include/linux/pid.h
1632  */
1633 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
1634                         struct pid_namespace *ns);
1635 
1636 static inline pid_t task_pid_nr(struct task_struct *tsk)
1637 {
1638         return tsk->pid;
1639 }
1640 
1641 static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
1642                                         struct pid_namespace *ns)
1643 {
1644         return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1645 }
1646 
1647 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1648 {
1649         return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1650 }
1651 
1652 
1653 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1654 {
1655         return tsk->tgid;
1656 }
1657 
1658 pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1659 
1660 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1661 {
1662         return pid_vnr(task_tgid(tsk));
1663 }
1664 
1665 
1666 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
1667                                         struct pid_namespace *ns)
1668 {
1669         return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1670 }
1671 
1672 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1673 {
1674         return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1675 }
1676 
1677 
1678 static inline pid_t task_session_nr_ns(struct task_struct *tsk,
1679                                         struct pid_namespace *ns)
1680 {
1681         return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1682 }
1683 
1684 static inline pid_t task_session_vnr(struct task_struct *tsk)
1685 {
1686         return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1687 }
1688 
1689 /* obsolete, do not use */
1690 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1691 {
1692         return task_pgrp_nr_ns(tsk, &init_pid_ns);
1693 }
1694 
1695 /**
1696  * pid_alive - check that a task structure is not stale
1697  * @p: Task structure to be checked.
1698  *
1699  * Test if a process is not yet dead (at most zombie state)
1700  * If pid_alive fails, then pointers within the task structure
1701  * can be stale and must not be dereferenced.
1702  */
1703 static inline int pid_alive(struct task_struct *p)
1704 {
1705         return p->pids[PIDTYPE_PID].pid != NULL;
1706 }
1707 
1708 /**
1709  * is_global_init - check if a task structure is init
1710  * @tsk: Task structure to be checked.
1711  *
1712  * Check if a task structure is the first user space task the kernel created.
1713  */
1714 static inline int is_global_init(struct task_struct *tsk)
1715 {
1716         return tsk->pid == 1;
1717 }
1718 
1719 /*
1720  * is_container_init:
1721  * check whether in the task is init in its own pid namespace.
1722  */
1723 extern int is_container_init(struct task_struct *tsk);
1724 
1725 extern struct pid *cad_pid;
1726 
1727 extern void free_task(struct task_struct *tsk);
1728 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
1729 
1730 extern void __put_task_struct(struct task_struct *t);
1731 
1732 static inline void put_task_struct(struct task_struct *t)
1733 {
1734         if (atomic_dec_and_test(&t->usage))
1735                 __put_task_struct(t);
1736 }
1737 
1738 extern void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st);
1739 extern void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st);
1740 
1741 /*
1742  * Per process flags
1743  */
1744 #define PF_EXITING      0x00000004      /* getting shut down */
1745 #define PF_EXITPIDONE   0x00000008      /* pi exit done on shut down */
1746 #define PF_VCPU         0x00000010      /* I'm a virtual CPU */
1747 #define PF_WQ_WORKER    0x00000020      /* I'm a workqueue worker */
1748 #define PF_FORKNOEXEC   0x00000040      /* forked but didn't exec */
1749 #define PF_MCE_PROCESS  0x00000080      /* process policy on mce errors */
1750 #define PF_SUPERPRIV    0x00000100      /* used super-user privileges */
1751 #define PF_DUMPCORE     0x00000200      /* dumped core */
1752 #define PF_SIGNALED     0x00000400      /* killed by a signal */
1753 #define PF_MEMALLOC     0x00000800      /* Allocating memory */
1754 #define PF_NPROC_EXCEEDED 0x00001000    /* set_user noticed that RLIMIT_NPROC was exceeded */
1755 #define PF_USED_MATH    0x00002000      /* if unset the fpu must be initialized before use */
1756 #define PF_NOFREEZE     0x00008000      /* this thread should not be frozen */
1757 #define PF_FROZEN       0x00010000      /* frozen for system suspend */
1758 #define PF_FSTRANS      0x00020000      /* inside a filesystem transaction */
1759 #define PF_KSWAPD       0x00040000      /* I am kswapd */
1760 #define PF_LESS_THROTTLE 0x00100000     /* Throttle me less: I clean memory */
1761 #define PF_KTHREAD      0x00200000      /* I am a kernel thread */
1762 #define PF_RANDOMIZE    0x00400000      /* randomize virtual address space */
1763 #define PF_SWAPWRITE    0x00800000      /* Allowed to write to swap */
1764 #define PF_SPREAD_PAGE  0x01000000      /* Spread page cache over cpuset */
1765 #define PF_SPREAD_SLAB  0x02000000      /* Spread some slab caches over cpuset */
1766 #define PF_THREAD_BOUND 0x04000000      /* Thread bound to specific cpu */
1767 #define PF_MCE_EARLY    0x08000000      /* Early kill for mce process policy */
1768 #define PF_MEMPOLICY    0x10000000      /* Non-default NUMA mempolicy */
1769 #define PF_MUTEX_TESTER 0x20000000      /* Thread belongs to the rt mutex tester */
1770 #define PF_FREEZER_SKIP 0x40000000      /* Freezer should not count it as freezable */
1771 
1772 /*
1773  * Only the _current_ task can read/write to tsk->flags, but other
1774  * tasks can access tsk->flags in readonly mode for example
1775  * with tsk_used_math (like during threaded core dumping).
1776  * There is however an exception to this rule during ptrace
1777  * or during fork: the ptracer task is allowed to write to the
1778  * child->flags of its traced child (same goes for fork, the parent
1779  * can write to the child->flags), because we're guaranteed the
1780  * child is not running and in turn not changing child->flags
1781  * at the same time the parent does it.
1782  */
1783 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1784 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1785 #define clear_used_math() clear_stopped_child_used_math(current)
1786 #define set_used_math() set_stopped_child_used_math(current)
1787 #define conditional_stopped_child_used_math(condition, child) \
1788         do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1789 #define conditional_used_math(condition) \
1790         conditional_stopped_child_used_math(condition, current)
1791 #define copy_to_stopped_child_used_math(child) \
1792         do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1793 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1794 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1795 #define used_math() tsk_used_math(current)
1796 
1797 /*
1798  * task->jobctl flags
1799  */
1800 #define JOBCTL_STOP_SIGMASK     0xffff  /* signr of the last group stop */
1801 
1802 #define JOBCTL_STOP_DEQUEUED_BIT 16     /* stop signal dequeued */
1803 #define JOBCTL_STOP_PENDING_BIT 17      /* task should stop for group stop */
1804 #define JOBCTL_STOP_CONSUME_BIT 18      /* consume group stop count */
1805 #define JOBCTL_TRAP_STOP_BIT    19      /* trap for STOP */
1806 #define JOBCTL_TRAP_NOTIFY_BIT  20      /* trap for NOTIFY */
1807 #define JOBCTL_TRAPPING_BIT     21      /* switching to TRACED */
1808 #define JOBCTL_LISTENING_BIT    22      /* ptracer is listening for events */
1809 
1810 #define JOBCTL_STOP_DEQUEUED    (1 << JOBCTL_STOP_DEQUEUED_BIT)
1811 #define JOBCTL_STOP_PENDING     (1 << JOBCTL_STOP_PENDING_BIT)
1812 #define JOBCTL_STOP_CONSUME     (1 << JOBCTL_STOP_CONSUME_BIT)
1813 #define JOBCTL_TRAP_STOP        (1 << JOBCTL_TRAP_STOP_BIT)
1814 #define JOBCTL_TRAP_NOTIFY      (1 << JOBCTL_TRAP_NOTIFY_BIT)
1815 #define JOBCTL_TRAPPING         (1 << JOBCTL_TRAPPING_BIT)
1816 #define JOBCTL_LISTENING        (1 << JOBCTL_LISTENING_BIT)
1817 
1818 #define JOBCTL_TRAP_MASK        (JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
1819 #define JOBCTL_PENDING_MASK     (JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)
1820 
1821 extern bool task_set_jobctl_pending(struct task_struct *task,
1822                                     unsigned int mask);
1823 extern void task_clear_jobctl_trapping(struct task_struct *task);
1824 extern void task_clear_jobctl_pending(struct task_struct *task,
1825                                       unsigned int mask);
1826 
1827 #ifdef CONFIG_PREEMPT_RCU
1828 
1829 #define RCU_READ_UNLOCK_BLOCKED (1 << 0) /* blocked while in RCU read-side. */
1830 #define RCU_READ_UNLOCK_NEED_QS (1 << 1) /* RCU core needs CPU response. */
1831 
1832 static inline void rcu_copy_process(struct task_struct *p)
1833 {
1834         p->rcu_read_lock_nesting = 0;
1835         p->rcu_read_unlock_special = 0;
1836 #ifdef CONFIG_TREE_PREEMPT_RCU
1837         p->rcu_blocked_node = NULL;
1838 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
1839 #ifdef CONFIG_RCU_BOOST
1840         p->rcu_boost_mutex = NULL;
1841 #endif /* #ifdef CONFIG_RCU_BOOST */
1842         INIT_LIST_HEAD(&p->rcu_node_entry);
1843 }
1844 
1845 #else
1846 
1847 static inline void rcu_copy_process(struct task_struct *p)
1848 {
1849 }
1850 
1851 #endif
1852 
1853 static inline void rcu_switch(struct task_struct *prev,
1854                               struct task_struct *next)
1855 {
1856 #ifdef CONFIG_RCU_USER_QS
1857         rcu_user_hooks_switch(prev, next);
1858 #endif
1859 }
1860 
1861 static inline void tsk_restore_flags(struct task_struct *task,
1862                                 unsigned long orig_flags, unsigned long flags)
1863 {
1864         task->flags &= ~flags;
1865         task->flags |= orig_flags & flags;
1866 }
1867 
1868 #ifdef CONFIG_SMP
1869 extern void do_set_cpus_allowed(struct task_struct *p,
1870                                const struct cpumask *new_mask);
1871 
1872 extern int set_cpus_allowed_ptr(struct task_struct *p,
1873                                 const struct cpumask *new_mask);
1874 #else
1875 static inline void do_set_cpus_allowed(struct task_struct *p,
1876                                       const struct cpumask *new_mask)
1877 {
1878 }
1879 static inline int set_cpus_allowed_ptr(struct task_struct *p,
1880                                        const struct cpumask *new_mask)
1881 {
1882         if (!cpumask_test_cpu(0, new_mask))
1883                 return -EINVAL;
1884         return 0;
1885 }
1886 #endif
1887 
1888 #ifdef CONFIG_NO_HZ
1889 void calc_load_enter_idle(void);
1890 void calc_load_exit_idle(void);
1891 #else
1892 static inline void calc_load_enter_idle(void) { }
1893 static inline void calc_load_exit_idle(void) { }
1894 #endif /* CONFIG_NO_HZ */
1895 
1896 #ifndef CONFIG_CPUMASK_OFFSTACK
1897 static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
1898 {
1899         return set_cpus_allowed_ptr(p, &new_mask);
1900 }
1901 #endif
1902 
1903 /*
1904  * Do not use outside of architecture code which knows its limitations.
1905  *
1906  * sched_clock() has no promise of monotonicity or bounded drift between
1907  * CPUs, use (which you should not) requires disabling IRQs.
1908  *
1909  * Please use one of the three interfaces below.
1910  */
1911 extern unsigned long long notrace sched_clock(void);
1912 /*
1913  * See the comment in kernel/sched/clock.c
1914  */
1915 extern u64 cpu_clock(int cpu);
1916 extern u64 local_clock(void);
1917 extern u64 sched_clock_cpu(int cpu);
1918 
1919 
1920 extern void sched_clock_init(void);
1921 
1922 #ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
1923 static inline void sched_clock_tick(void)
1924 {
1925 }
1926 
1927 static inline void sched_clock_idle_sleep_event(void)
1928 {
1929 }
1930 
1931 static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
1932 {
1933 }
1934 #else
1935 /*
1936  * Architectures can set this to 1 if they have specified
1937  * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
1938  * but then during bootup it turns out that sched_clock()
1939  * is reliable after all:
1940  */
1941 extern int sched_clock_stable;
1942 
1943 extern void sched_clock_tick(void);
1944 extern void sched_clock_idle_sleep_event(void);
1945 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
1946 #endif
1947 
1948 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
1949 /*
1950  * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
1951  * The reason for this explicit opt-in is not to have perf penalty with
1952  * slow sched_clocks.
1953  */
1954 extern void enable_sched_clock_irqtime(void);
1955 extern void disable_sched_clock_irqtime(void);
1956 #else
1957 static inline void enable_sched_clock_irqtime(void) {}
1958 static inline void disable_sched_clock_irqtime(void) {}
1959 #endif
1960 
1961 extern unsigned long long
1962 task_sched_runtime(struct task_struct *task);
1963 
1964 /* sched_exec is called by processes performing an exec */
1965 #ifdef CONFIG_SMP
1966 extern void sched_exec(void);
1967 #else
1968 #define sched_exec()   {}
1969 #endif
1970 
1971 extern void sched_clock_idle_sleep_event(void);
1972 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
1973 
1974 #ifdef CONFIG_HOTPLUG_CPU
1975 extern void idle_task_exit(void);
1976 #else
1977 static inline void idle_task_exit(void) {}
1978 #endif
1979 
1980 #if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP)
1981 extern void wake_up_idle_cpu(int cpu);
1982 #else
1983 static inline void wake_up_idle_cpu(int cpu) { }
1984 #endif
1985 
1986 extern unsigned int sysctl_sched_latency;
1987 extern unsigned int sysctl_sched_min_granularity;
1988 extern unsigned int sysctl_sched_wakeup_granularity;
1989 extern unsigned int sysctl_sched_child_runs_first;
1990 
1991 enum sched_tunable_scaling {
1992         SCHED_TUNABLESCALING_NONE,
1993         SCHED_TUNABLESCALING_LOG,
1994         SCHED_TUNABLESCALING_LINEAR,
1995         SCHED_TUNABLESCALING_END,
1996 };
1997 extern enum sched_tunable_scaling sysctl_sched_tunable_scaling;
1998 
1999 #ifdef CONFIG_SCHED_DEBUG
2000 extern unsigned int sysctl_sched_migration_cost;
2001 extern unsigned int sysctl_sched_nr_migrate;
2002 extern unsigned int sysctl_sched_time_avg;
2003 extern unsigned int sysctl_timer_migration;
2004 extern unsigned int sysctl_sched_shares_window;
2005 
2006 int sched_proc_update_handler(struct ctl_table *table, int write,
2007                 void __user *buffer, size_t *length,
2008                 loff_t *ppos);
2009 #endif
2010 #ifdef CONFIG_SCHED_DEBUG
2011 static inline unsigned int get_sysctl_timer_migration(void)
2012 {
2013         return sysctl_timer_migration;
2014 }
2015 #else
2016 static inline unsigned int get_sysctl_timer_migration(void)
2017 {
2018         return 1;
2019 }
2020 #endif
2021 extern unsigned int sysctl_sched_rt_period;
2022 extern int sysctl_sched_rt_runtime;
2023 
2024 int sched_rt_handler(struct ctl_table *table, int write,
2025                 void __user *buffer, size_t *lenp,
2026                 loff_t *ppos);
2027 
2028 #ifdef CONFIG_SCHED_AUTOGROUP
2029 extern unsigned int sysctl_sched_autogroup_enabled;
2030 
2031 extern void sched_autogroup_create_attach(struct task_struct *p);
2032 extern void sched_autogroup_detach(struct task_struct *p);
2033 extern void sched_autogroup_fork(struct signal_struct *sig);
2034 extern void sched_autogroup_exit(struct signal_struct *sig);
2035 #ifdef CONFIG_PROC_FS
2036 extern void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m);
2037 extern int proc_sched_autogroup_set_nice(struct task_struct *p, int nice);
2038 #endif
2039 #else
2040 static inline void sched_autogroup_create_attach(struct task_struct *p) { }
2041 static inline void sched_autogroup_detach(struct task_struct *p) { }
2042 static inline void sched_autogroup_fork(struct signal_struct *sig) { }
2043 static inline void sched_autogroup_exit(struct signal_struct *sig) { }
2044 #endif
2045 
2046 #ifdef CONFIG_CFS_BANDWIDTH
2047 extern unsigned int sysctl_sched_cfs_bandwidth_slice;
2048 #endif
2049 
2050 #ifdef CONFIG_RT_MUTEXES
2051 extern int rt_mutex_getprio(struct task_struct *p);
2052 extern void rt_mutex_setprio(struct task_struct *p, int prio);
2053 extern void rt_mutex_adjust_pi(struct task_struct *p);
2054 static inline bool tsk_is_pi_blocked(struct task_struct *tsk)
2055 {
2056         return tsk->pi_blocked_on != NULL;
2057 }
2058 #else
2059 static inline int rt_mutex_getprio(struct task_struct *p)
2060 {
2061         return p->normal_prio;
2062 }
2063 # define rt_mutex_adjust_pi(p)          do { } while (0)
2064 static inline bool tsk_is_pi_blocked(struct task_struct *tsk)
2065 {
2066         return false;
2067 }
2068 #endif
2069 
2070 extern bool yield_to(struct task_struct *p, bool preempt);
2071 extern void set_user_nice(struct task_struct *p, long nice);
2072 extern int task_prio(const struct task_struct *p);
2073 extern int task_nice(const struct task_struct *p);
2074 extern int can_nice(const struct task_struct *p, const int nice);
2075 extern int task_curr(const struct task_struct *p);
2076 extern int idle_cpu(int cpu);
2077 extern int sched_setscheduler(struct task_struct *, int,
2078                               const struct sched_param *);
2079 extern int sched_setscheduler_nocheck(struct task_struct *, int,
2080                                       const struct sched_param *);
2081 extern struct task_struct *idle_task(int cpu);
2082 /**
2083  * is_idle_task - is the specified task an idle task?
2084  * @p: the task in question.
2085  */
2086 static inline bool is_idle_task(const struct task_struct *p)
2087 {
2088         return p->pid == 0;
2089 }
2090 extern struct task_struct *curr_task(int cpu);
2091 extern void set_curr_task(int cpu, struct task_struct *p);
2092 
2093 void yield(void);
2094 
2095 /*
2096  * The default (Linux) execution domain.
2097  */
2098 extern struct exec_domain       default_exec_domain;
2099 
2100 union thread_union {
2101         struct thread_info thread_info;
2102         unsigned long stack[THREAD_SIZE/sizeof(long)];
2103 };
2104 
2105 #ifndef __HAVE_ARCH_KSTACK_END
2106 static inline int kstack_end(void *addr)
2107 {
2108         /* Reliable end of stack detection:
2109          * Some APM bios versions misalign the stack
2110          */
2111         return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
2112 }
2113 #endif
2114 
2115 extern union thread_union init_thread_union;
2116 extern struct task_struct init_task;
2117 
2118 extern struct   mm_struct init_mm;
2119 
2120 extern struct pid_namespace init_pid_ns;
2121 
2122 /*
2123  * find a task by one of its numerical ids
2124  *
2125  * find_task_by_pid_ns():
2126  *      finds a task by its pid in the specified namespace
2127  * find_task_by_vpid():
2128  *      finds a task by its virtual pid
2129  *
2130  * see also find_vpid() etc in include/linux/pid.h
2131  */
2132 
2133 extern struct task_struct *find_task_by_vpid(pid_t nr);
2134 extern struct task_struct *find_task_by_pid_ns(pid_t nr,
2135                 struct pid_namespace *ns);
2136 
2137 extern void __set_special_pids(struct pid *pid);
2138 
2139 /* per-UID process charging. */
2140 extern struct user_struct * alloc_uid(kuid_t);
2141 static inline struct user_struct *get_uid(struct user_struct *u)
2142 {
2143         atomic_inc(&u->__count);
2144         return u;
2145 }
2146 extern void free_uid(struct user_struct *);
2147 
2148 #include <asm/current.h>
2149 
2150 extern void xtime_update(unsigned long ticks);
2151 
2152 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2153 extern int wake_up_process(struct task_struct *tsk);
2154 extern void wake_up_new_task(struct task_struct *tsk);
2155 #ifdef CONFIG_SMP
2156  extern void kick_process(struct task_struct *tsk);
2157 #else
2158  static inline void kick_process(struct task_struct *tsk) { }
2159 #endif
2160 extern void sched_fork(struct task_struct *p);
2161 extern void sched_dead(struct task_struct *p);
2162 
2163 extern void proc_caches_init(void);
2164 extern void flush_signals(struct task_struct *);
2165 extern void __flush_signals(struct task_struct *);
2166 extern void ignore_signals(struct task_struct *);
2167 extern void flush_signal_handlers(struct task_struct *, int force_default);
2168 extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
2169 
2170 static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
2171 {
2172         unsigned long flags;
2173         int ret;
2174 
2175         spin_lock_irqsave(&tsk->sighand->siglock, flags);
2176         ret = dequeue_signal(tsk, mask, info);
2177         spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
2178 
2179         return ret;
2180 }
2181 
2182 extern void block_all_signals(int (*notifier)(void *priv), void *priv,
2183                               sigset_t *mask);
2184 extern void unblock_all_signals(void);
2185 extern void release_task(struct task_struct * p);
2186 extern int send_sig_info(int, struct siginfo *, struct task_struct *);
2187 extern int force_sigsegv(int, struct task_struct *);
2188 extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2189 extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
2190 extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2191 extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *,
2192                                 const struct cred *, u32);
2193 extern int kill_pgrp(struct pid *pid, int sig, int priv);
2194 extern int kill_pid(struct pid *pid, int sig, int priv);
2195 extern int kill_proc_info(int, struct siginfo *, pid_t);
2196 extern __must_check bool do_notify_parent(struct task_struct *, int);
2197 extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
2198 extern void force_sig(int, struct task_struct *);
2199 extern int send_sig(int, struct task_struct *, int);
2200 extern int zap_other_threads(struct task_struct *p);
2201 extern struct sigqueue *sigqueue_alloc(void);
2202 extern void sigqueue_free(struct sigqueue *);
2203 extern int send_sigqueue(struct sigqueue *,  struct task_struct *, int group);
2204 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
2205 extern int do_sigaltstack(const stack_t __user *, stack_t __user *, unsigned long);
2206 
2207 static inline void restore_saved_sigmask(void)
2208 {
2209         if (test_and_clear_restore_sigmask())
2210                 __set_current_blocked(&current->saved_sigmask);
2211 }
2212 
2213 static inline sigset_t *sigmask_to_save(void)
2214 {
2215         sigset_t *res = &current->blocked;
2216         if (unlikely(test_restore_sigmask()))
2217                 res = &current->saved_sigmask;
2218         return res;
2219 }
2220 
2221 static inline int kill_cad_pid(int sig, int priv)
2222 {
2223         return kill_pid(cad_pid, sig, priv);
2224 }
2225 
2226 /* These can be the second arg to send_sig_info/send_group_sig_info.  */
2227 #define SEND_SIG_NOINFO ((struct siginfo *) 0)
2228 #define SEND_SIG_PRIV   ((struct siginfo *) 1)
2229 #define SEND_SIG_FORCED ((struct siginfo *) 2)
2230 
2231 /*
2232  * True if we are on the alternate signal stack.
2233  */
2234 static inline int on_sig_stack(unsigned long sp)
2235 {
2236 #ifdef CONFIG_STACK_GROWSUP
2237         return sp >= current->sas_ss_sp &&
2238                 sp - current->sas_ss_sp < current->sas_ss_size;
2239 #else
2240         return sp > current->sas_ss_sp &&
2241                 sp - current->sas_ss_sp <= current->sas_ss_size;
2242 #endif
2243 }
2244 
2245 static inline int sas_ss_flags(unsigned long sp)
2246 {
2247         return (current->sas_ss_size == 0 ? SS_DISABLE
2248                 : on_sig_stack(sp) ? SS_ONSTACK : 0);
2249 }
2250 
2251 /*
2252  * Routines for handling mm_structs
2253  */
2254 extern struct mm_struct * mm_alloc(void);
2255 
2256 /* mmdrop drops the mm and the page tables */
2257 extern void __mmdrop(struct mm_struct *);
2258 static inline void mmdrop(struct mm_struct * mm)
2259 {
2260         if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2261                 __mmdrop(mm);
2262 }
2263 
2264 /* mmput gets rid of the mappings and all user-space */
2265 extern void mmput(struct mm_struct *);
2266 /* Grab a reference to a task's mm, if it is not already going away */
2267 extern struct mm_struct *get_task_mm(struct task_struct *task);
2268 /*
2269  * Grab a reference to a task's mm, if it is not already going away
2270  * and ptrace_may_access with the mode parameter passed to it
2271  * succeeds.
2272  */
2273 extern struct mm_struct *mm_access(struct task_struct *task, unsigned int mode);
2274 /* Remove the current tasks stale references to the old mm_struct */
2275 extern void mm_release(struct task_struct *, struct mm_struct *);
2276 /* Allocate a new mm structure and copy contents from tsk->mm */
2277 extern struct mm_struct *dup_mm(struct task_struct *tsk);
2278 
2279 extern int copy_thread(unsigned long, unsigned long, unsigned long,
2280                         struct task_struct *, struct pt_regs *);
2281 extern void flush_thread(void);
2282 extern void exit_thread(void);
2283 
2284 extern void exit_files(struct task_struct *);
2285 extern void __cleanup_sighand(struct sighand_struct *);
2286 
2287 extern void exit_itimers(struct signal_struct *);
2288 extern void flush_itimer_signals(void);
2289 
2290 extern void do_group_exit(int);
2291 
2292 extern void daemonize(const char *, ...);
2293 extern int allow_signal(int);
2294 extern int disallow_signal(int);
2295 
2296 extern int do_execve(const char *,
2297                      const char __user * const __user *,
2298                      const char __user * const __user *, struct pt_regs *);
2299 extern long do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *);
2300 struct task_struct *fork_idle(int);
2301 #ifdef CONFIG_GENERIC_KERNEL_THREAD
2302 extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
2303 #endif
2304 
2305 extern void set_task_comm(struct task_struct *tsk, char *from);
2306 extern char *get_task_comm(char *to, struct task_struct *tsk);
2307 
2308 #ifdef CONFIG_SMP
2309 void scheduler_ipi(void);
2310 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
2311 #else
2312 static inline void scheduler_ipi(void) { }
2313 static inline unsigned long wait_task_inactive(struct task_struct *p,
2314                                                long match_state)
2315 {
2316         return 1;
2317 }
2318 #endif
2319 
2320 #define next_task(p) \
2321         list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
2322 
2323 #define for_each_process(p) \
2324         for (p = &init_task ; (p = next_task(p)) != &init_task ; )
2325 
2326 extern bool current_is_single_threaded(void);
2327 
2328 /*
2329  * Careful: do_each_thread/while_each_thread is a double loop so
2330  *          'break' will not work as expected - use goto instead.
2331  */
2332 #define do_each_thread(g, t) \
2333         for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
2334 
2335 #define while_each_thread(g, t) \
2336         while ((t = next_thread(t)) != g)
2337 
2338 static inline int get_nr_threads(struct task_struct *tsk)
2339 {
2340         return tsk->signal->nr_threads;
2341 }
2342 
2343 static inline bool thread_group_leader(struct task_struct *p)
2344 {
2345         return p->exit_signal >= 0;
2346 }
2347 
2348 /* Do to the insanities of de_thread it is possible for a process
2349  * to have the pid of the thread group leader without actually being
2350  * the thread group leader.  For iteration through the pids in proc
2351  * all we care about is that we have a task with the appropriate
2352  * pid, we don't actually care if we have the right task.
2353  */
2354 static inline int has_group_leader_pid(struct task_struct *p)
2355 {
2356         return p->pid == p->tgid;
2357 }
2358 
2359 static inline
2360 int same_thread_group(struct task_struct *p1, struct task_struct *p2)
2361 {
2362         return p1->tgid == p2->tgid;
2363 }
2364 
2365 static inline struct task_struct *next_thread(const struct task_struct *p)
2366 {
2367         return list_entry_rcu(p->thread_group.next,
2368                               struct task_struct, thread_group);
2369 }
2370 
2371 static inline int thread_group_empty(struct task_struct *p)
2372 {
2373         return list_empty(&p->thread_group);
2374 }
2375 
2376 #define delay_group_leader(p) \
2377                 (thread_group_leader(p) && !thread_group_empty(p))
2378 
2379 /*
2380  * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
2381  * subscriptions and synchronises with wait4().  Also used in procfs.  Also
2382  * pins the final release of task.io_context.  Also protects ->cpuset and
2383  * ->cgroup.subsys[]. And ->vfork_done.
2384  *
2385  * Nests both inside and outside of read_lock(&tasklist_lock).
2386  * It must not be nested with write_lock_irq(&tasklist_lock),
2387  * neither inside nor outside.
2388  */
2389 static inline void task_lock(struct task_struct *p)
2390 {
2391         spin_lock(&p->alloc_lock);
2392 }
2393 
2394 static inline void task_unlock(struct task_struct *p)
2395 {
2396         spin_unlock(&p->alloc_lock);
2397 }
2398 
2399 extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
2400                                                         unsigned long *flags);
2401 
2402 static inline struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
2403                                                        unsigned long *flags)
2404 {
2405         struct sighand_struct *ret;
2406 
2407         ret = __lock_task_sighand(tsk, flags);
2408         (void)__cond_lock(&tsk->sighand->siglock, ret);
2409         return ret;
2410 }
2411 
2412 static inline void unlock_task_sighand(struct task_struct *tsk,
2413                                                 unsigned long *flags)
2414 {
2415         spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
2416 }
2417 
2418 #ifdef CONFIG_CGROUPS
2419 static inline void threadgroup_change_begin(struct task_struct *tsk)
2420 {
2421         down_read(&tsk->signal->group_rwsem);
2422 }
2423 static inline void threadgroup_change_end(struct task_struct *tsk)
2424 {
2425         up_read(&tsk->signal->group_rwsem);
2426 }
2427 
2428 /**
2429  * threadgroup_lock - lock threadgroup
2430  * @tsk: member task of the threadgroup to lock
2431  *
2432  * Lock the threadgroup @tsk belongs to.  No new task is allowed to enter
2433  * and member tasks aren't allowed to exit (as indicated by PF_EXITING) or
2434  * perform exec.  This is useful for cases where the threadgroup needs to
2435  * stay stable across blockable operations.
2436  *
2437  * fork and exit paths explicitly call threadgroup_change_{begin|end}() for
2438  * synchronization.  While held, no new task will be added to threadgroup
2439  * and no existing live task will have its PF_EXITING set.
2440  *
2441  * During exec, a task goes and puts its thread group through unusual
2442  * changes.  After de-threading, exclusive access is assumed to resources
2443  * which are usually shared by tasks in the same group - e.g. sighand may
2444  * be replaced with a new one.  Also, the exec'ing task takes over group
2445  * leader role including its pid.  Exclude these changes while locked by
2446  * grabbing cred_guard_mutex which is used to synchronize exec path.
2447  */
2448 static inline void threadgroup_lock(struct task_struct *tsk)
2449 {
2450         /*
2451          * exec uses exit for de-threading nesting group_rwsem inside
2452          * cred_guard_mutex. Grab cred_guard_mutex first.
2453          */
2454         mutex_lock(&tsk->signal->cred_guard_mutex);
2455         down_write(&tsk->signal->group_rwsem);
2456 }
2457 
2458 /**
2459  * threadgroup_unlock - unlock threadgroup
2460  * @tsk: member task of the threadgroup to unlock
2461  *
2462  * Reverse threadgroup_lock().
2463  */
2464 static inline void threadgroup_unlock(struct task_struct *tsk)
2465 {
2466         up_write(&tsk->signal->group_rwsem);
2467         mutex_unlock(&tsk->signal->cred_guard_mutex);
2468 }
2469 #else
2470 static inline void threadgroup_change_begin(struct task_struct *tsk) {}
2471 static inline void threadgroup_change_end(struct task_struct *tsk) {}
2472 static inline void threadgroup_lock(struct task_struct *tsk) {}
2473 static inline void threadgroup_unlock(struct task_struct *tsk) {}
2474 #endif
2475 
2476 #ifndef __HAVE_THREAD_FUNCTIONS
2477 
2478 #define task_thread_info(task)  ((struct thread_info *)(task)->stack)
2479 #define task_stack_page(task)   ((task)->stack)
2480 
2481 static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
2482 {
2483         *task_thread_info(p) = *task_thread_info(org);
2484         task_thread_info(p)->task = p;
2485 }
2486 
2487 static inline unsigned long *end_of_stack(struct task_struct *p)
2488 {
2489         return (unsigned long *)(task_thread_info(p) + 1);
2490 }
2491 
2492 #endif
2493 
2494 static inline int object_is_on_stack(void *obj)
2495 {
2496         void *stack = task_stack_page(current);
2497 
2498         return (obj >= stack) && (obj < (stack + THREAD_SIZE));
2499 }
2500 
2501 extern void thread_info_cache_init(void);
2502 
2503 #ifdef CONFIG_DEBUG_STACK_USAGE
2504 static inline unsigned long stack_not_used(struct task_struct *p)
2505 {
2506         unsigned long *n = end_of_stack(p);
2507 
2508         do {    /* Skip over canary */
2509                 n++;
2510         } while (!*n);
2511 
2512         return (unsigned long)n - (unsigned long)end_of_stack(p);
2513 }
2514 #endif
2515 
2516 /* set thread flags in other task's structures
2517  * - see asm/thread_info.h for TIF_xxxx flags available
2518  */
2519 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2520 {
2521         set_ti_thread_flag(task_thread_info(tsk), flag);
2522 }
2523 
2524 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2525 {
2526         clear_ti_thread_flag(task_thread_info(tsk), flag);
2527 }
2528 
2529 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2530 {
2531         return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2532 }
2533 
2534 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2535 {
2536         return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2537 }
2538 
2539 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2540 {
2541         return test_ti_thread_flag(task_thread_info(tsk), flag);
2542 }
2543 
2544 static inline void set_tsk_need_resched(struct task_struct *tsk)
2545 {
2546         set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2547 }
2548 
2549 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2550 {
2551         clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2552 }
2553 
2554 static inline int test_tsk_need_resched(struct task_struct *tsk)
2555 {
2556         return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2557 }
2558 
2559 static inline int restart_syscall(void)
2560 {
2561         set_tsk_thread_flag(current, TIF_SIGPENDING);
2562         return -ERESTARTNOINTR;
2563 }
2564 
2565 static inline int signal_pending(struct task_struct *p)
2566 {
2567         return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
2568 }
2569 
2570 static inline int __fatal_signal_pending(struct task_struct *p)
2571 {
2572         return unlikely(sigismember(&p->pending.signal, SIGKILL));
2573 }
2574 
2575 static inline int fatal_signal_pending(struct task_struct *p)
2576 {
2577         return signal_pending(p) && __fatal_signal_pending(p);
2578 }
2579 
2580 static inline int signal_pending_state(long state, struct task_struct *p)
2581 {
2582         if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
2583                 return 0;
2584         if (!signal_pending(p))
2585                 return 0;
2586 
2587         return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
2588 }
2589 
2590 static inline int need_resched(void)
2591 {
2592         return unlikely(test_thread_flag(TIF_NEED_RESCHED));
2593 }
2594 
2595 /*
2596  * cond_resched() and cond_resched_lock(): latency reduction via
2597  * explicit rescheduling in places that are safe. The return
2598  * value indicates whether a reschedule was done in fact.
2599  * cond_resched_lock() will drop the spinlock before scheduling,
2600  * cond_resched_softirq() will enable bhs before scheduling.
2601  */
2602 extern int _cond_resched(void);
2603 
2604 #define cond_resched() ({                       \
2605         __might_sleep(__FILE__, __LINE__, 0);   \
2606         _cond_resched();                        \
2607 })
2608 
2609 extern int __cond_resched_lock(spinlock_t *lock);
2610 
2611 #ifdef CONFIG_PREEMPT_COUNT
2612 #define PREEMPT_LOCK_OFFSET     PREEMPT_OFFSET
2613 #else
2614 #define PREEMPT_LOCK_OFFSET     0
2615 #endif
2616 
2617 #define cond_resched_lock(lock) ({                              \
2618         __might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET); \
2619         __cond_resched_lock(lock);                              \
2620 })
2621 
2622 extern int __cond_resched_softirq(void);
2623 
2624 #define cond_resched_softirq() ({                                       \
2625         __might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET);      \
2626         __cond_resched_softirq();                                       \
2627 })
2628 
2629 /*
2630  * Does a critical section need to be broken due to another
2631  * task waiting?: (technically does not depend on CONFIG_PREEMPT,
2632  * but a general need for low latency)
2633  */
2634 static inline int spin_needbreak(spinlock_t *lock)
2635 {
2636 #ifdef CONFIG_PREEMPT
2637         return spin_is_contended(lock);
2638 #else
2639         return 0;
2640 #endif
2641 }
2642 
2643 /*
2644  * Thread group CPU time accounting.
2645  */
2646 void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
2647 void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
2648 
2649 static inline void thread_group_cputime_init(struct signal_struct *sig)
2650 {
2651         raw_spin_lock_init(&sig->cputimer.lock);
2652 }
2653 
2654 /*
2655  * Reevaluate whether the task has signals pending delivery.
2656  * Wake the task if so.
2657  * This is required every time the blocked sigset_t changes.
2658  * callers must hold sighand->siglock.
2659  */
2660 extern void recalc_sigpending_and_wake(struct task_struct *t);
2661 extern void recalc_sigpending(void);
2662 
2663 extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
2664 
2665 static inline void signal_wake_up(struct task_struct *t, bool resume)
2666 {
2667         signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0);
2668 }
2669 static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
2670 {
2671         signal_wake_up_state(t, resume ? __TASK_TRACED : 0);
2672 }
2673 
2674 /*
2675  * Wrappers for p->thread_info->cpu access. No-op on UP.
2676  */
2677 #ifdef CONFIG_SMP
2678 
2679 static inline unsigned int task_cpu(const struct task_struct *p)
2680 {
2681         return task_thread_info(p)->cpu;
2682 }
2683 
2684 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2685 
2686 #else
2687 
2688 static inline unsigned int task_cpu(const struct task_struct *p)
2689 {
2690         return 0;
2691 }
2692 
2693 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2694 {
2695 }
2696 
2697 #endif /* CONFIG_SMP */
2698 
2699 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2700 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2701 
2702 extern void normalize_rt_tasks(void);
2703 
2704 #ifdef CONFIG_CGROUP_SCHED
2705 
2706 extern struct task_group root_task_group;
2707 
2708 extern struct task_group *sched_create_group(struct task_group *parent);
2709 extern void sched_destroy_group(struct task_group *tg);
2710 extern void sched_move_task(struct task_struct *tsk);
2711 #ifdef CONFIG_FAIR_GROUP_SCHED
2712 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
2713 extern unsigned long sched_group_shares(struct task_group *tg);
2714 #endif
2715 #ifdef CONFIG_RT_GROUP_SCHED
2716 extern int sched_group_set_rt_runtime(struct task_group *tg,
2717                                       long rt_runtime_us);
2718 extern long sched_group_rt_runtime(struct task_group *tg);
2719 extern int sched_group_set_rt_period(struct task_group *tg,
2720                                       long rt_period_us);
2721 extern long sched_group_rt_period(struct task_group *tg);
2722 extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk);
2723 #endif
2724 #endif /* CONFIG_CGROUP_SCHED */
2725 
2726 extern int task_can_switch_user(struct user_struct *up,
2727                                         struct task_struct *tsk);
2728 
2729 #ifdef CONFIG_TASK_XACCT
2730 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2731 {
2732         tsk->ioac.rchar += amt;
2733 }
2734 
2735 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2736 {
2737         tsk->ioac.wchar += amt;
2738 }
2739 
2740 static inline void inc_syscr(struct task_struct *tsk)
2741 {
2742         tsk->ioac.syscr++;
2743 }
2744 
2745 static inline void inc_syscw(struct task_struct *tsk)
2746 {
2747         tsk->ioac.syscw++;
2748 }
2749 #else
2750 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2751 {
2752 }
2753 
2754 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2755 {
2756 }
2757 
2758 static inline void inc_syscr(struct task_struct *tsk)
2759 {
2760 }
2761 
2762 static inline void inc_syscw(struct task_struct *tsk)
2763 {
2764 }
2765 #endif
2766 
2767 #ifndef TASK_SIZE_OF
2768 #define TASK_SIZE_OF(tsk)       TASK_SIZE
2769 #endif
2770 
2771 #ifdef CONFIG_MM_OWNER
2772 extern void mm_update_next_owner(struct mm_struct *mm);
2773 extern void mm_init_owner(struct mm_struct *mm, struct task_struct *p);
2774 #else
2775 static inline void mm_update_next_owner(struct mm_struct *mm)
2776 {
2777 }
2778 
2779 static inline void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
2780 {
2781 }
2782 #endif /* CONFIG_MM_OWNER */
2783 
2784 static inline unsigned long task_rlimit(const struct task_struct *tsk,
2785                 unsigned int limit)
2786 {
2787         return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_cur);
2788 }
2789 
2790 static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
2791                 unsigned int limit)
2792 {
2793         return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_max);
2794 }
2795 
2796 static inline unsigned long rlimit(unsigned int limit)
2797 {
2798         return task_rlimit(current, limit);
2799 }
2800 
2801 static inline unsigned long rlimit_max(unsigned int limit)
2802 {
2803         return task_rlimit_max(current, limit);
2804 }
2805 
2806 #endif
2807 

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