Version:  2.0.40 2.2.26 2.4.37 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17

Linux/include/linux/sched.h

  1 #ifndef _LINUX_SCHED_H
  2 #define _LINUX_SCHED_H
  3 
  4 #include <uapi/linux/sched.h>
  5 
  6 
  7 struct sched_param {
  8         int sched_priority;
  9 };
 10 
 11 #include <asm/param.h>  /* for HZ */
 12 
 13 #include <linux/capability.h>
 14 #include <linux/threads.h>
 15 #include <linux/kernel.h>
 16 #include <linux/types.h>
 17 #include <linux/timex.h>
 18 #include <linux/jiffies.h>
 19 #include <linux/rbtree.h>
 20 #include <linux/thread_info.h>
 21 #include <linux/cpumask.h>
 22 #include <linux/errno.h>
 23 #include <linux/nodemask.h>
 24 #include <linux/mm_types.h>
 25 
 26 #include <asm/page.h>
 27 #include <asm/ptrace.h>
 28 #include <asm/cputime.h>
 29 
 30 #include <linux/smp.h>
 31 #include <linux/sem.h>
 32 #include <linux/signal.h>
 33 #include <linux/compiler.h>
 34 #include <linux/completion.h>
 35 #include <linux/pid.h>
 36 #include <linux/percpu.h>
 37 #include <linux/topology.h>
 38 #include <linux/proportions.h>
 39 #include <linux/seccomp.h>
 40 #include <linux/rcupdate.h>
 41 #include <linux/rculist.h>
 42 #include <linux/rtmutex.h>
 43 
 44 #include <linux/time.h>
 45 #include <linux/param.h>
 46 #include <linux/resource.h>
 47 #include <linux/timer.h>
 48 #include <linux/hrtimer.h>
 49 #include <linux/task_io_accounting.h>
 50 #include <linux/latencytop.h>
 51 #include <linux/cred.h>
 52 #include <linux/llist.h>
 53 #include <linux/uidgid.h>
 54 
 55 #include <asm/processor.h>
 56 
 57 struct exec_domain;
 58 struct futex_pi_state;
 59 struct robust_list_head;
 60 struct bio_list;
 61 struct fs_struct;
 62 struct perf_event_context;
 63 struct blk_plug;
 64 
 65 /*
 66  * List of flags we want to share for kernel threads,
 67  * if only because they are not used by them anyway.
 68  */
 69 #define CLONE_KERNEL    (CLONE_FS | CLONE_FILES | CLONE_SIGHAND)
 70 
 71 /*
 72  * These are the constant used to fake the fixed-point load-average
 73  * counting. Some notes:
 74  *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
 75  *    a load-average precision of 10 bits integer + 11 bits fractional
 76  *  - if you want to count load-averages more often, you need more
 77  *    precision, or rounding will get you. With 2-second counting freq,
 78  *    the EXP_n values would be 1981, 2034 and 2043 if still using only
 79  *    11 bit fractions.
 80  */
 81 extern unsigned long avenrun[];         /* Load averages */
 82 extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
 83 
 84 #define FSHIFT          11              /* nr of bits of precision */
 85 #define FIXED_1         (1<<FSHIFT)     /* 1.0 as fixed-point */
 86 #define LOAD_FREQ       (5*HZ+1)        /* 5 sec intervals */
 87 #define EXP_1           1884            /* 1/exp(5sec/1min) as fixed-point */
 88 #define EXP_5           2014            /* 1/exp(5sec/5min) */
 89 #define EXP_15          2037            /* 1/exp(5sec/15min) */
 90 
 91 #define CALC_LOAD(load,exp,n) \
 92         load *= exp; \
 93         load += n*(FIXED_1-exp); \
 94         load >>= FSHIFT;
 95 
 96 extern unsigned long total_forks;
 97 extern int nr_threads;
 98 DECLARE_PER_CPU(unsigned long, process_counts);
 99 extern int nr_processes(void);
100 extern unsigned long nr_running(void);
101 extern unsigned long nr_uninterruptible(void);
102 extern unsigned long nr_iowait(void);
103 extern unsigned long nr_iowait_cpu(int cpu);
104 extern unsigned long this_cpu_load(void);
105 
106 
107 extern void calc_global_load(unsigned long ticks);
108 extern void update_cpu_load_nohz(void);
109 
110 /* Notifier for when a task gets migrated to a new CPU */
111 struct task_migration_notifier {
112         struct task_struct *task;
113         int from_cpu;
114         int to_cpu;
115 };
116 extern void register_task_migration_notifier(struct notifier_block *n);
117 
118 extern unsigned long get_parent_ip(unsigned long addr);
119 
120 extern void dump_cpu_task(int cpu);
121 
122 struct seq_file;
123 struct cfs_rq;
124 struct task_group;
125 #ifdef CONFIG_SCHED_DEBUG
126 extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
127 extern void proc_sched_set_task(struct task_struct *p);
128 extern void
129 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
130 #else
131 static inline void
132 proc_sched_show_task(struct task_struct *p, struct seq_file *m)
133 {
134 }
135 static inline void proc_sched_set_task(struct task_struct *p)
136 {
137 }
138 static inline void
139 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
140 {
141 }
142 #endif
143 
144 /*
145  * Task state bitmask. NOTE! These bits are also
146  * encoded in fs/proc/array.c: get_task_state().
147  *
148  * We have two separate sets of flags: task->state
149  * is about runnability, while task->exit_state are
150  * about the task exiting. Confusing, but this way
151  * modifying one set can't modify the other one by
152  * mistake.
153  */
154 #define TASK_RUNNING            0
155 #define TASK_INTERRUPTIBLE      1
156 #define TASK_UNINTERRUPTIBLE    2
157 #define __TASK_STOPPED          4
158 #define __TASK_TRACED           8
159 /* in tsk->exit_state */
160 #define EXIT_ZOMBIE             16
161 #define EXIT_DEAD               32
162 /* in tsk->state again */
163 #define TASK_DEAD               64
164 #define TASK_WAKEKILL           128
165 #define TASK_WAKING             256
166 #define TASK_STATE_MAX          512
167 
168 #define TASK_STATE_TO_CHAR_STR "RSDTtZXxKW"
169 
170 extern char ___assert_task_state[1 - 2*!!(
171                 sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
172 
173 /* Convenience macros for the sake of set_task_state */
174 #define TASK_KILLABLE           (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
175 #define TASK_STOPPED            (TASK_WAKEKILL | __TASK_STOPPED)
176 #define TASK_TRACED             (TASK_WAKEKILL | __TASK_TRACED)
177 
178 /* Convenience macros for the sake of wake_up */
179 #define TASK_NORMAL             (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
180 #define TASK_ALL                (TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
181 
182 /* get_task_state() */
183 #define TASK_REPORT             (TASK_RUNNING | TASK_INTERRUPTIBLE | \
184                                  TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
185                                  __TASK_TRACED)
186 
187 #define task_is_traced(task)    ((task->state & __TASK_TRACED) != 0)
188 #define task_is_stopped(task)   ((task->state & __TASK_STOPPED) != 0)
189 #define task_is_dead(task)      ((task)->exit_state != 0)
190 #define task_is_stopped_or_traced(task) \
191                         ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
192 #define task_contributes_to_load(task)  \
193                                 ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
194                                  (task->flags & PF_FROZEN) == 0)
195 
196 #define __set_task_state(tsk, state_value)              \
197         do { (tsk)->state = (state_value); } while (0)
198 #define set_task_state(tsk, state_value)                \
199         set_mb((tsk)->state, (state_value))
200 
201 /*
202  * set_current_state() includes a barrier so that the write of current->state
203  * is correctly serialised wrt the caller's subsequent test of whether to
204  * actually sleep:
205  *
206  *      set_current_state(TASK_UNINTERRUPTIBLE);
207  *      if (do_i_need_to_sleep())
208  *              schedule();
209  *
210  * If the caller does not need such serialisation then use __set_current_state()
211  */
212 #define __set_current_state(state_value)                        \
213         do { current->state = (state_value); } while (0)
214 #define set_current_state(state_value)          \
215         set_mb(current->state, (state_value))
216 
217 /* Task command name length */
218 #define TASK_COMM_LEN 16
219 
220 #include <linux/spinlock.h>
221 
222 /*
223  * This serializes "schedule()" and also protects
224  * the run-queue from deletions/modifications (but
225  * _adding_ to the beginning of the run-queue has
226  * a separate lock).
227  */
228 extern rwlock_t tasklist_lock;
229 extern spinlock_t mmlist_lock;
230 
231 struct task_struct;
232 
233 #ifdef CONFIG_PROVE_RCU
234 extern int lockdep_tasklist_lock_is_held(void);
235 #endif /* #ifdef CONFIG_PROVE_RCU */
236 
237 extern void sched_init(void);
238 extern void sched_init_smp(void);
239 extern asmlinkage void schedule_tail(struct task_struct *prev);
240 extern void init_idle(struct task_struct *idle, int cpu);
241 extern void init_idle_bootup_task(struct task_struct *idle);
242 
243 extern int runqueue_is_locked(int cpu);
244 
245 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ)
246 extern void nohz_balance_enter_idle(int cpu);
247 extern void set_cpu_sd_state_idle(void);
248 extern int get_nohz_timer_target(void);
249 #else
250 static inline void nohz_balance_enter_idle(int cpu) { }
251 static inline void set_cpu_sd_state_idle(void) { }
252 #endif
253 
254 /*
255  * Only dump TASK_* tasks. (0 for all tasks)
256  */
257 extern void show_state_filter(unsigned long state_filter);
258 
259 static inline void show_state(void)
260 {
261         show_state_filter(0);
262 }
263 
264 extern void show_regs(struct pt_regs *);
265 
266 /*
267  * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
268  * task), SP is the stack pointer of the first frame that should be shown in the back
269  * trace (or NULL if the entire call-chain of the task should be shown).
270  */
271 extern void show_stack(struct task_struct *task, unsigned long *sp);
272 
273 void io_schedule(void);
274 long io_schedule_timeout(long timeout);
275 
276 extern void cpu_init (void);
277 extern void trap_init(void);
278 extern void update_process_times(int user);
279 extern void scheduler_tick(void);
280 
281 extern void sched_show_task(struct task_struct *p);
282 
283 #ifdef CONFIG_LOCKUP_DETECTOR
284 extern void touch_softlockup_watchdog(void);
285 extern void touch_softlockup_watchdog_sync(void);
286 extern void touch_all_softlockup_watchdogs(void);
287 extern int proc_dowatchdog_thresh(struct ctl_table *table, int write,
288                                   void __user *buffer,
289                                   size_t *lenp, loff_t *ppos);
290 extern unsigned int  softlockup_panic;
291 void lockup_detector_init(void);
292 #else
293 static inline void touch_softlockup_watchdog(void)
294 {
295 }
296 static inline void touch_softlockup_watchdog_sync(void)
297 {
298 }
299 static inline void touch_all_softlockup_watchdogs(void)
300 {
301 }
302 static inline void lockup_detector_init(void)
303 {
304 }
305 #endif
306 
307 #ifdef CONFIG_DETECT_HUNG_TASK
308 extern unsigned int  sysctl_hung_task_panic;
309 extern unsigned long sysctl_hung_task_check_count;
310 extern unsigned long sysctl_hung_task_timeout_secs;
311 extern unsigned long sysctl_hung_task_warnings;
312 extern int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
313                                          void __user *buffer,
314                                          size_t *lenp, loff_t *ppos);
315 #else
316 /* Avoid need for ifdefs elsewhere in the code */
317 enum { sysctl_hung_task_timeout_secs = 0 };
318 #endif
319 
320 /* Attach to any functions which should be ignored in wchan output. */
321 #define __sched         __attribute__((__section__(".sched.text")))
322 
323 /* Linker adds these: start and end of __sched functions */
324 extern char __sched_text_start[], __sched_text_end[];
325 
326 /* Is this address in the __sched functions? */
327 extern int in_sched_functions(unsigned long addr);
328 
329 #define MAX_SCHEDULE_TIMEOUT    LONG_MAX
330 extern signed long schedule_timeout(signed long timeout);
331 extern signed long schedule_timeout_interruptible(signed long timeout);
332 extern signed long schedule_timeout_killable(signed long timeout);
333 extern signed long schedule_timeout_uninterruptible(signed long timeout);
334 asmlinkage void schedule(void);
335 extern void schedule_preempt_disabled(void);
336 extern int mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner);
337 
338 struct nsproxy;
339 struct user_namespace;
340 
341 /*
342  * Default maximum number of active map areas, this limits the number of vmas
343  * per mm struct. Users can overwrite this number by sysctl but there is a
344  * problem.
345  *
346  * When a program's coredump is generated as ELF format, a section is created
347  * per a vma. In ELF, the number of sections is represented in unsigned short.
348  * This means the number of sections should be smaller than 65535 at coredump.
349  * Because the kernel adds some informative sections to a image of program at
350  * generating coredump, we need some margin. The number of extra sections is
351  * 1-3 now and depends on arch. We use "5" as safe margin, here.
352  */
353 #define MAPCOUNT_ELF_CORE_MARGIN        (5)
354 #define DEFAULT_MAX_MAP_COUNT   (USHRT_MAX - MAPCOUNT_ELF_CORE_MARGIN)
355 
356 extern int sysctl_max_map_count;
357 
358 #include <linux/aio.h>
359 
360 #ifdef CONFIG_MMU
361 extern void arch_pick_mmap_layout(struct mm_struct *mm);
362 extern unsigned long
363 arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
364                        unsigned long, unsigned long);
365 extern unsigned long
366 arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
367                           unsigned long len, unsigned long pgoff,
368                           unsigned long flags);
369 extern void arch_unmap_area(struct mm_struct *, unsigned long);
370 extern void arch_unmap_area_topdown(struct mm_struct *, unsigned long);
371 #else
372 static inline void arch_pick_mmap_layout(struct mm_struct *mm) {}
373 #endif
374 
375 
376 extern void set_dumpable(struct mm_struct *mm, int value);
377 extern int get_dumpable(struct mm_struct *mm);
378 
379 /* get/set_dumpable() values */
380 #define SUID_DUMPABLE_DISABLED  0
381 #define SUID_DUMPABLE_ENABLED   1
382 #define SUID_DUMPABLE_SAFE      2
383 
384 /* mm flags */
385 /* dumpable bits */
386 #define MMF_DUMPABLE      0  /* core dump is permitted */
387 #define MMF_DUMP_SECURELY 1  /* core file is readable only by root */
388 
389 #define MMF_DUMPABLE_BITS 2
390 #define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
391 
392 /* coredump filter bits */
393 #define MMF_DUMP_ANON_PRIVATE   2
394 #define MMF_DUMP_ANON_SHARED    3
395 #define MMF_DUMP_MAPPED_PRIVATE 4
396 #define MMF_DUMP_MAPPED_SHARED  5
397 #define MMF_DUMP_ELF_HEADERS    6
398 #define MMF_DUMP_HUGETLB_PRIVATE 7
399 #define MMF_DUMP_HUGETLB_SHARED  8
400 
401 #define MMF_DUMP_FILTER_SHIFT   MMF_DUMPABLE_BITS
402 #define MMF_DUMP_FILTER_BITS    7
403 #define MMF_DUMP_FILTER_MASK \
404         (((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
405 #define MMF_DUMP_FILTER_DEFAULT \
406         ((1 << MMF_DUMP_ANON_PRIVATE) | (1 << MMF_DUMP_ANON_SHARED) |\
407          (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
408 
409 #ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
410 # define MMF_DUMP_MASK_DEFAULT_ELF      (1 << MMF_DUMP_ELF_HEADERS)
411 #else
412 # define MMF_DUMP_MASK_DEFAULT_ELF      0
413 #endif
414                                         /* leave room for more dump flags */
415 #define MMF_VM_MERGEABLE        16      /* KSM may merge identical pages */
416 #define MMF_VM_HUGEPAGE         17      /* set when VM_HUGEPAGE is set on vma */
417 #define MMF_EXE_FILE_CHANGED    18      /* see prctl_set_mm_exe_file() */
418 
419 #define MMF_HAS_UPROBES         19      /* has uprobes */
420 #define MMF_RECALC_UPROBES      20      /* MMF_HAS_UPROBES can be wrong */
421 
422 #define MMF_INIT_MASK           (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
423 
424 struct sighand_struct {
425         atomic_t                count;
426         struct k_sigaction      action[_NSIG];
427         spinlock_t              siglock;
428         wait_queue_head_t       signalfd_wqh;
429 };
430 
431 struct pacct_struct {
432         int                     ac_flag;
433         long                    ac_exitcode;
434         unsigned long           ac_mem;
435         cputime_t               ac_utime, ac_stime;
436         unsigned long           ac_minflt, ac_majflt;
437 };
438 
439 struct cpu_itimer {
440         cputime_t expires;
441         cputime_t incr;
442         u32 error;
443         u32 incr_error;
444 };
445 
446 /**
447  * struct cputime - snaphsot of system and user cputime
448  * @utime: time spent in user mode
449  * @stime: time spent in system mode
450  *
451  * Gathers a generic snapshot of user and system time.
452  */
453 struct cputime {
454         cputime_t utime;
455         cputime_t stime;
456 };
457 
458 /**
459  * struct task_cputime - collected CPU time counts
460  * @utime:              time spent in user mode, in &cputime_t units
461  * @stime:              time spent in kernel mode, in &cputime_t units
462  * @sum_exec_runtime:   total time spent on the CPU, in nanoseconds
463  *
464  * This is an extension of struct cputime that includes the total runtime
465  * spent by the task from the scheduler point of view.
466  *
467  * As a result, this structure groups together three kinds of CPU time
468  * that are tracked for threads and thread groups.  Most things considering
469  * CPU time want to group these counts together and treat all three
470  * of them in parallel.
471  */
472 struct task_cputime {
473         cputime_t utime;
474         cputime_t stime;
475         unsigned long long sum_exec_runtime;
476 };
477 /* Alternate field names when used to cache expirations. */
478 #define prof_exp        stime
479 #define virt_exp        utime
480 #define sched_exp       sum_exec_runtime
481 
482 #define INIT_CPUTIME    \
483         (struct task_cputime) {                                 \
484                 .utime = 0,                                     \
485                 .stime = 0,                                     \
486                 .sum_exec_runtime = 0,                          \
487         }
488 
489 /*
490  * Disable preemption until the scheduler is running.
491  * Reset by start_kernel()->sched_init()->init_idle().
492  *
493  * We include PREEMPT_ACTIVE to avoid cond_resched() from working
494  * before the scheduler is active -- see should_resched().
495  */
496 #define INIT_PREEMPT_COUNT      (1 + PREEMPT_ACTIVE)
497 
498 /**
499  * struct thread_group_cputimer - thread group interval timer counts
500  * @cputime:            thread group interval timers.
501  * @running:            non-zero when there are timers running and
502  *                      @cputime receives updates.
503  * @lock:               lock for fields in this struct.
504  *
505  * This structure contains the version of task_cputime, above, that is
506  * used for thread group CPU timer calculations.
507  */
508 struct thread_group_cputimer {
509         struct task_cputime cputime;
510         int running;
511         raw_spinlock_t lock;
512 };
513 
514 #include <linux/rwsem.h>
515 struct autogroup;
516 
517 /*
518  * NOTE! "signal_struct" does not have its own
519  * locking, because a shared signal_struct always
520  * implies a shared sighand_struct, so locking
521  * sighand_struct is always a proper superset of
522  * the locking of signal_struct.
523  */
524 struct signal_struct {
525         atomic_t                sigcnt;
526         atomic_t                live;
527         int                     nr_threads;
528 
529         wait_queue_head_t       wait_chldexit;  /* for wait4() */
530 
531         /* current thread group signal load-balancing target: */
532         struct task_struct      *curr_target;
533 
534         /* shared signal handling: */
535         struct sigpending       shared_pending;
536 
537         /* thread group exit support */
538         int                     group_exit_code;
539         /* overloaded:
540          * - notify group_exit_task when ->count is equal to notify_count
541          * - everyone except group_exit_task is stopped during signal delivery
542          *   of fatal signals, group_exit_task processes the signal.
543          */
544         int                     notify_count;
545         struct task_struct      *group_exit_task;
546 
547         /* thread group stop support, overloads group_exit_code too */
548         int                     group_stop_count;
549         unsigned int            flags; /* see SIGNAL_* flags below */
550 
551         /*
552          * PR_SET_CHILD_SUBREAPER marks a process, like a service
553          * manager, to re-parent orphan (double-forking) child processes
554          * to this process instead of 'init'. The service manager is
555          * able to receive SIGCHLD signals and is able to investigate
556          * the process until it calls wait(). All children of this
557          * process will inherit a flag if they should look for a
558          * child_subreaper process at exit.
559          */
560         unsigned int            is_child_subreaper:1;
561         unsigned int            has_child_subreaper:1;
562 
563         /* POSIX.1b Interval Timers */
564         struct list_head posix_timers;
565 
566         /* ITIMER_REAL timer for the process */
567         struct hrtimer real_timer;
568         struct pid *leader_pid;
569         ktime_t it_real_incr;
570 
571         /*
572          * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
573          * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
574          * values are defined to 0 and 1 respectively
575          */
576         struct cpu_itimer it[2];
577 
578         /*
579          * Thread group totals for process CPU timers.
580          * See thread_group_cputimer(), et al, for details.
581          */
582         struct thread_group_cputimer cputimer;
583 
584         /* Earliest-expiration cache. */
585         struct task_cputime cputime_expires;
586 
587         struct list_head cpu_timers[3];
588 
589         struct pid *tty_old_pgrp;
590 
591         /* boolean value for session group leader */
592         int leader;
593 
594         struct tty_struct *tty; /* NULL if no tty */
595 
596 #ifdef CONFIG_SCHED_AUTOGROUP
597         struct autogroup *autogroup;
598 #endif
599         /*
600          * Cumulative resource counters for dead threads in the group,
601          * and for reaped dead child processes forked by this group.
602          * Live threads maintain their own counters and add to these
603          * in __exit_signal, except for the group leader.
604          */
605         cputime_t utime, stime, cutime, cstime;
606         cputime_t gtime;
607         cputime_t cgtime;
608 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
609         struct cputime prev_cputime;
610 #endif
611         unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
612         unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
613         unsigned long inblock, oublock, cinblock, coublock;
614         unsigned long maxrss, cmaxrss;
615         struct task_io_accounting ioac;
616 
617         /*
618          * Cumulative ns of schedule CPU time fo dead threads in the
619          * group, not including a zombie group leader, (This only differs
620          * from jiffies_to_ns(utime + stime) if sched_clock uses something
621          * other than jiffies.)
622          */
623         unsigned long long sum_sched_runtime;
624 
625         /*
626          * We don't bother to synchronize most readers of this at all,
627          * because there is no reader checking a limit that actually needs
628          * to get both rlim_cur and rlim_max atomically, and either one
629          * alone is a single word that can safely be read normally.
630          * getrlimit/setrlimit use task_lock(current->group_leader) to
631          * protect this instead of the siglock, because they really
632          * have no need to disable irqs.
633          */
634         struct rlimit rlim[RLIM_NLIMITS];
635 
636 #ifdef CONFIG_BSD_PROCESS_ACCT
637         struct pacct_struct pacct;      /* per-process accounting information */
638 #endif
639 #ifdef CONFIG_TASKSTATS
640         struct taskstats *stats;
641 #endif
642 #ifdef CONFIG_AUDIT
643         unsigned audit_tty;
644         struct tty_audit_buf *tty_audit_buf;
645 #endif
646 #ifdef CONFIG_CGROUPS
647         /*
648          * group_rwsem prevents new tasks from entering the threadgroup and
649          * member tasks from exiting,a more specifically, setting of
650          * PF_EXITING.  fork and exit paths are protected with this rwsem
651          * using threadgroup_change_begin/end().  Users which require
652          * threadgroup to remain stable should use threadgroup_[un]lock()
653          * which also takes care of exec path.  Currently, cgroup is the
654          * only user.
655          */
656         struct rw_semaphore group_rwsem;
657 #endif
658 
659         oom_flags_t oom_flags;
660         short oom_score_adj;            /* OOM kill score adjustment */
661         short oom_score_adj_min;        /* OOM kill score adjustment min value.
662                                          * Only settable by CAP_SYS_RESOURCE. */
663 
664         struct mutex cred_guard_mutex;  /* guard against foreign influences on
665                                          * credential calculations
666                                          * (notably. ptrace) */
667 };
668 
669 /*
670  * Bits in flags field of signal_struct.
671  */
672 #define SIGNAL_STOP_STOPPED     0x00000001 /* job control stop in effect */
673 #define SIGNAL_STOP_CONTINUED   0x00000002 /* SIGCONT since WCONTINUED reap */
674 #define SIGNAL_GROUP_EXIT       0x00000004 /* group exit in progress */
675 /*
676  * Pending notifications to parent.
677  */
678 #define SIGNAL_CLD_STOPPED      0x00000010
679 #define SIGNAL_CLD_CONTINUED    0x00000020
680 #define SIGNAL_CLD_MASK         (SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
681 
682 #define SIGNAL_UNKILLABLE       0x00000040 /* for init: ignore fatal signals */
683 
684 /* If true, all threads except ->group_exit_task have pending SIGKILL */
685 static inline int signal_group_exit(const struct signal_struct *sig)
686 {
687         return  (sig->flags & SIGNAL_GROUP_EXIT) ||
688                 (sig->group_exit_task != NULL);
689 }
690 
691 /*
692  * Some day this will be a full-fledged user tracking system..
693  */
694 struct user_struct {
695         atomic_t __count;       /* reference count */
696         atomic_t processes;     /* How many processes does this user have? */
697         atomic_t files;         /* How many open files does this user have? */
698         atomic_t sigpending;    /* How many pending signals does this user have? */
699 #ifdef CONFIG_INOTIFY_USER
700         atomic_t inotify_watches; /* How many inotify watches does this user have? */
701         atomic_t inotify_devs;  /* How many inotify devs does this user have opened? */
702 #endif
703 #ifdef CONFIG_FANOTIFY
704         atomic_t fanotify_listeners;
705 #endif
706 #ifdef CONFIG_EPOLL
707         atomic_long_t epoll_watches; /* The number of file descriptors currently watched */
708 #endif
709 #ifdef CONFIG_POSIX_MQUEUE
710         /* protected by mq_lock */
711         unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */
712 #endif
713         unsigned long locked_shm; /* How many pages of mlocked shm ? */
714 
715 #ifdef CONFIG_KEYS
716         struct key *uid_keyring;        /* UID specific keyring */
717         struct key *session_keyring;    /* UID's default session keyring */
718 #endif
719 
720         /* Hash table maintenance information */
721         struct hlist_node uidhash_node;
722         kuid_t uid;
723 
724 #ifdef CONFIG_PERF_EVENTS
725         atomic_long_t locked_vm;
726 #endif
727 };
728 
729 extern int uids_sysfs_init(void);
730 
731 extern struct user_struct *find_user(kuid_t);
732 
733 extern struct user_struct root_user;
734 #define INIT_USER (&root_user)
735 
736 
737 struct backing_dev_info;
738 struct reclaim_state;
739 
740 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
741 struct sched_info {
742         /* cumulative counters */
743         unsigned long pcount;         /* # of times run on this cpu */
744         unsigned long long run_delay; /* time spent waiting on a runqueue */
745 
746         /* timestamps */
747         unsigned long long last_arrival,/* when we last ran on a cpu */
748                            last_queued; /* when we were last queued to run */
749 };
750 #endif /* defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) */
751 
752 #ifdef CONFIG_TASK_DELAY_ACCT
753 struct task_delay_info {
754         spinlock_t      lock;
755         unsigned int    flags;  /* Private per-task flags */
756 
757         /* For each stat XXX, add following, aligned appropriately
758          *
759          * struct timespec XXX_start, XXX_end;
760          * u64 XXX_delay;
761          * u32 XXX_count;
762          *
763          * Atomicity of updates to XXX_delay, XXX_count protected by
764          * single lock above (split into XXX_lock if contention is an issue).
765          */
766 
767         /*
768          * XXX_count is incremented on every XXX operation, the delay
769          * associated with the operation is added to XXX_delay.
770          * XXX_delay contains the accumulated delay time in nanoseconds.
771          */
772         struct timespec blkio_start, blkio_end; /* Shared by blkio, swapin */
773         u64 blkio_delay;        /* wait for sync block io completion */
774         u64 swapin_delay;       /* wait for swapin block io completion */
775         u32 blkio_count;        /* total count of the number of sync block */
776                                 /* io operations performed */
777         u32 swapin_count;       /* total count of the number of swapin block */
778                                 /* io operations performed */
779 
780         struct timespec freepages_start, freepages_end;
781         u64 freepages_delay;    /* wait for memory reclaim */
782         u32 freepages_count;    /* total count of memory reclaim */
783 };
784 #endif  /* CONFIG_TASK_DELAY_ACCT */
785 
786 static inline int sched_info_on(void)
787 {
788 #ifdef CONFIG_SCHEDSTATS
789         return 1;
790 #elif defined(CONFIG_TASK_DELAY_ACCT)
791         extern int delayacct_on;
792         return delayacct_on;
793 #else
794         return 0;
795 #endif
796 }
797 
798 enum cpu_idle_type {
799         CPU_IDLE,
800         CPU_NOT_IDLE,
801         CPU_NEWLY_IDLE,
802         CPU_MAX_IDLE_TYPES
803 };
804 
805 /*
806  * Increase resolution of nice-level calculations for 64-bit architectures.
807  * The extra resolution improves shares distribution and load balancing of
808  * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup
809  * hierarchies, especially on larger systems. This is not a user-visible change
810  * and does not change the user-interface for setting shares/weights.
811  *
812  * We increase resolution only if we have enough bits to allow this increased
813  * resolution (i.e. BITS_PER_LONG > 32). The costs for increasing resolution
814  * when BITS_PER_LONG <= 32 are pretty high and the returns do not justify the
815  * increased costs.
816  */
817 #if 0 /* BITS_PER_LONG > 32 -- currently broken: it increases power usage under light load  */
818 # define SCHED_LOAD_RESOLUTION  10
819 # define scale_load(w)          ((w) << SCHED_LOAD_RESOLUTION)
820 # define scale_load_down(w)     ((w) >> SCHED_LOAD_RESOLUTION)
821 #else
822 # define SCHED_LOAD_RESOLUTION  0
823 # define scale_load(w)          (w)
824 # define scale_load_down(w)     (w)
825 #endif
826 
827 #define SCHED_LOAD_SHIFT        (10 + SCHED_LOAD_RESOLUTION)
828 #define SCHED_LOAD_SCALE        (1L << SCHED_LOAD_SHIFT)
829 
830 /*
831  * Increase resolution of cpu_power calculations
832  */
833 #define SCHED_POWER_SHIFT       10
834 #define SCHED_POWER_SCALE       (1L << SCHED_POWER_SHIFT)
835 
836 /*
837  * sched-domains (multiprocessor balancing) declarations:
838  */
839 #ifdef CONFIG_SMP
840 #define SD_LOAD_BALANCE         0x0001  /* Do load balancing on this domain. */
841 #define SD_BALANCE_NEWIDLE      0x0002  /* Balance when about to become idle */
842 #define SD_BALANCE_EXEC         0x0004  /* Balance on exec */
843 #define SD_BALANCE_FORK         0x0008  /* Balance on fork, clone */
844 #define SD_BALANCE_WAKE         0x0010  /* Balance on wakeup */
845 #define SD_WAKE_AFFINE          0x0020  /* Wake task to waking CPU */
846 #define SD_SHARE_CPUPOWER       0x0080  /* Domain members share cpu power */
847 #define SD_SHARE_PKG_RESOURCES  0x0200  /* Domain members share cpu pkg resources */
848 #define SD_SERIALIZE            0x0400  /* Only a single load balancing instance */
849 #define SD_ASYM_PACKING         0x0800  /* Place busy groups earlier in the domain */
850 #define SD_PREFER_SIBLING       0x1000  /* Prefer to place tasks in a sibling domain */
851 #define SD_OVERLAP              0x2000  /* sched_domains of this level overlap */
852 
853 extern int __weak arch_sd_sibiling_asym_packing(void);
854 
855 struct sched_group_power {
856         atomic_t ref;
857         /*
858          * CPU power of this group, SCHED_LOAD_SCALE being max power for a
859          * single CPU.
860          */
861         unsigned int power, power_orig;
862         unsigned long next_update;
863         /*
864          * Number of busy cpus in this group.
865          */
866         atomic_t nr_busy_cpus;
867 
868         unsigned long cpumask[0]; /* iteration mask */
869 };
870 
871 struct sched_group {
872         struct sched_group *next;       /* Must be a circular list */
873         atomic_t ref;
874 
875         unsigned int group_weight;
876         struct sched_group_power *sgp;
877 
878         /*
879          * The CPUs this group covers.
880          *
881          * NOTE: this field is variable length. (Allocated dynamically
882          * by attaching extra space to the end of the structure,
883          * depending on how many CPUs the kernel has booted up with)
884          */
885         unsigned long cpumask[0];
886 };
887 
888 static inline struct cpumask *sched_group_cpus(struct sched_group *sg)
889 {
890         return to_cpumask(sg->cpumask);
891 }
892 
893 /*
894  * cpumask masking which cpus in the group are allowed to iterate up the domain
895  * tree.
896  */
897 static inline struct cpumask *sched_group_mask(struct sched_group *sg)
898 {
899         return to_cpumask(sg->sgp->cpumask);
900 }
901 
902 /**
903  * group_first_cpu - Returns the first cpu in the cpumask of a sched_group.
904  * @group: The group whose first cpu is to be returned.
905  */
906 static inline unsigned int group_first_cpu(struct sched_group *group)
907 {
908         return cpumask_first(sched_group_cpus(group));
909 }
910 
911 struct sched_domain_attr {
912         int relax_domain_level;
913 };
914 
915 #define SD_ATTR_INIT    (struct sched_domain_attr) {    \
916         .relax_domain_level = -1,                       \
917 }
918 
919 extern int sched_domain_level_max;
920 
921 struct sched_domain {
922         /* These fields must be setup */
923         struct sched_domain *parent;    /* top domain must be null terminated */
924         struct sched_domain *child;     /* bottom domain must be null terminated */
925         struct sched_group *groups;     /* the balancing groups of the domain */
926         unsigned long min_interval;     /* Minimum balance interval ms */
927         unsigned long max_interval;     /* Maximum balance interval ms */
928         unsigned int busy_factor;       /* less balancing by factor if busy */
929         unsigned int imbalance_pct;     /* No balance until over watermark */
930         unsigned int cache_nice_tries;  /* Leave cache hot tasks for # tries */
931         unsigned int busy_idx;
932         unsigned int idle_idx;
933         unsigned int newidle_idx;
934         unsigned int wake_idx;
935         unsigned int forkexec_idx;
936         unsigned int smt_gain;
937         int flags;                      /* See SD_* */
938         int level;
939 
940         /* Runtime fields. */
941         unsigned long last_balance;     /* init to jiffies. units in jiffies */
942         unsigned int balance_interval;  /* initialise to 1. units in ms. */
943         unsigned int nr_balance_failed; /* initialise to 0 */
944 
945         u64 last_update;
946 
947 #ifdef CONFIG_SCHEDSTATS
948         /* load_balance() stats */
949         unsigned int lb_count[CPU_MAX_IDLE_TYPES];
950         unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
951         unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
952         unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
953         unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
954         unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
955         unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
956         unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
957 
958         /* Active load balancing */
959         unsigned int alb_count;
960         unsigned int alb_failed;
961         unsigned int alb_pushed;
962 
963         /* SD_BALANCE_EXEC stats */
964         unsigned int sbe_count;
965         unsigned int sbe_balanced;
966         unsigned int sbe_pushed;
967 
968         /* SD_BALANCE_FORK stats */
969         unsigned int sbf_count;
970         unsigned int sbf_balanced;
971         unsigned int sbf_pushed;
972 
973         /* try_to_wake_up() stats */
974         unsigned int ttwu_wake_remote;
975         unsigned int ttwu_move_affine;
976         unsigned int ttwu_move_balance;
977 #endif
978 #ifdef CONFIG_SCHED_DEBUG
979         char *name;
980 #endif
981         union {
982                 void *private;          /* used during construction */
983                 struct rcu_head rcu;    /* used during destruction */
984         };
985 
986         unsigned int span_weight;
987         /*
988          * Span of all CPUs in this domain.
989          *
990          * NOTE: this field is variable length. (Allocated dynamically
991          * by attaching extra space to the end of the structure,
992          * depending on how many CPUs the kernel has booted up with)
993          */
994         unsigned long span[0];
995 };
996 
997 static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
998 {
999         return to_cpumask(sd->span);
1000 }
1001 
1002 extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1003                                     struct sched_domain_attr *dattr_new);
1004 
1005 /* Allocate an array of sched domains, for partition_sched_domains(). */
1006 cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
1007 void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
1008 
1009 /* Test a flag in parent sched domain */
1010 static inline int test_sd_parent(struct sched_domain *sd, int flag)
1011 {
1012         if (sd->parent && (sd->parent->flags & flag))
1013                 return 1;
1014 
1015         return 0;
1016 }
1017 
1018 unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu);
1019 unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu);
1020 
1021 bool cpus_share_cache(int this_cpu, int that_cpu);
1022 
1023 #else /* CONFIG_SMP */
1024 
1025 struct sched_domain_attr;
1026 
1027 static inline void
1028 partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1029                         struct sched_domain_attr *dattr_new)
1030 {
1031 }
1032 
1033 static inline bool cpus_share_cache(int this_cpu, int that_cpu)
1034 {
1035         return true;
1036 }
1037 
1038 #endif  /* !CONFIG_SMP */
1039 
1040 
1041 struct io_context;                      /* See blkdev.h */
1042 
1043 
1044 #ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
1045 extern void prefetch_stack(struct task_struct *t);
1046 #else
1047 static inline void prefetch_stack(struct task_struct *t) { }
1048 #endif
1049 
1050 struct audit_context;           /* See audit.c */
1051 struct mempolicy;
1052 struct pipe_inode_info;
1053 struct uts_namespace;
1054 
1055 struct rq;
1056 struct sched_domain;
1057 
1058 /*
1059  * wake flags
1060  */
1061 #define WF_SYNC         0x01            /* waker goes to sleep after wakup */
1062 #define WF_FORK         0x02            /* child wakeup after fork */
1063 #define WF_MIGRATED     0x04            /* internal use, task got migrated */
1064 
1065 #define ENQUEUE_WAKEUP          1
1066 #define ENQUEUE_HEAD            2
1067 #ifdef CONFIG_SMP
1068 #define ENQUEUE_WAKING          4       /* sched_class::task_waking was called */
1069 #else
1070 #define ENQUEUE_WAKING          0
1071 #endif
1072 
1073 #define DEQUEUE_SLEEP           1
1074 
1075 struct sched_class {
1076         const struct sched_class *next;
1077 
1078         void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags);
1079         void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags);
1080         void (*yield_task) (struct rq *rq);
1081         bool (*yield_to_task) (struct rq *rq, struct task_struct *p, bool preempt);
1082 
1083         void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags);
1084 
1085         struct task_struct * (*pick_next_task) (struct rq *rq);
1086         void (*put_prev_task) (struct rq *rq, struct task_struct *p);
1087 
1088 #ifdef CONFIG_SMP
1089         int  (*select_task_rq)(struct task_struct *p, int sd_flag, int flags);
1090         void (*migrate_task_rq)(struct task_struct *p, int next_cpu);
1091 
1092         void (*pre_schedule) (struct rq *this_rq, struct task_struct *task);
1093         void (*post_schedule) (struct rq *this_rq);
1094         void (*task_waking) (struct task_struct *task);
1095         void (*task_woken) (struct rq *this_rq, struct task_struct *task);
1096 
1097         void (*set_cpus_allowed)(struct task_struct *p,
1098                                  const struct cpumask *newmask);
1099 
1100         void (*rq_online)(struct rq *rq);
1101         void (*rq_offline)(struct rq *rq);
1102 #endif
1103 
1104         void (*set_curr_task) (struct rq *rq);
1105         void (*task_tick) (struct rq *rq, struct task_struct *p, int queued);
1106         void (*task_fork) (struct task_struct *p);
1107 
1108         void (*switched_from) (struct rq *this_rq, struct task_struct *task);
1109         void (*switched_to) (struct rq *this_rq, struct task_struct *task);
1110         void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
1111                              int oldprio);
1112 
1113         unsigned int (*get_rr_interval) (struct rq *rq,
1114                                          struct task_struct *task);
1115 
1116 #ifdef CONFIG_FAIR_GROUP_SCHED
1117         void (*task_move_group) (struct task_struct *p, int on_rq);
1118 #endif
1119 };
1120 
1121 struct load_weight {
1122         unsigned long weight, inv_weight;
1123 };
1124 
1125 struct sched_avg {
1126         /*
1127          * These sums represent an infinite geometric series and so are bound
1128          * above by 1024/(1-y).  Thus we only need a u32 to store them for for all
1129          * choices of y < 1-2^(-32)*1024.
1130          */
1131         u32 runnable_avg_sum, runnable_avg_period;
1132         u64 last_runnable_update;
1133         s64 decay_count;
1134         unsigned long load_avg_contrib;
1135 };
1136 
1137 #ifdef CONFIG_SCHEDSTATS
1138 struct sched_statistics {
1139         u64                     wait_start;
1140         u64                     wait_max;
1141         u64                     wait_count;
1142         u64                     wait_sum;
1143         u64                     iowait_count;
1144         u64                     iowait_sum;
1145 
1146         u64                     sleep_start;
1147         u64                     sleep_max;
1148         s64                     sum_sleep_runtime;
1149 
1150         u64                     block_start;
1151         u64                     block_max;
1152         u64                     exec_max;
1153         u64                     slice_max;
1154 
1155         u64                     nr_migrations_cold;
1156         u64                     nr_failed_migrations_affine;
1157         u64                     nr_failed_migrations_running;
1158         u64                     nr_failed_migrations_hot;
1159         u64                     nr_forced_migrations;
1160 
1161         u64                     nr_wakeups;
1162         u64                     nr_wakeups_sync;
1163         u64                     nr_wakeups_migrate;
1164         u64                     nr_wakeups_local;
1165         u64                     nr_wakeups_remote;
1166         u64                     nr_wakeups_affine;
1167         u64                     nr_wakeups_affine_attempts;
1168         u64                     nr_wakeups_passive;
1169         u64                     nr_wakeups_idle;
1170 };
1171 #endif
1172 
1173 struct sched_entity {
1174         struct load_weight      load;           /* for load-balancing */
1175         struct rb_node          run_node;
1176         struct list_head        group_node;
1177         unsigned int            on_rq;
1178 
1179         u64                     exec_start;
1180         u64                     sum_exec_runtime;
1181         u64                     vruntime;
1182         u64                     prev_sum_exec_runtime;
1183 
1184         u64                     nr_migrations;
1185 
1186 #ifdef CONFIG_SCHEDSTATS
1187         struct sched_statistics statistics;
1188 #endif
1189 
1190 #ifdef CONFIG_FAIR_GROUP_SCHED
1191         struct sched_entity     *parent;
1192         /* rq on which this entity is (to be) queued: */
1193         struct cfs_rq           *cfs_rq;
1194         /* rq "owned" by this entity/group: */
1195         struct cfs_rq           *my_q;
1196 #endif
1197 /*
1198  * Load-tracking only depends on SMP, FAIR_GROUP_SCHED dependency below may be
1199  * removed when useful for applications beyond shares distribution (e.g.
1200  * load-balance).
1201  */
1202 #if defined(CONFIG_SMP) && defined(CONFIG_FAIR_GROUP_SCHED)
1203         /* Per-entity load-tracking */
1204         struct sched_avg        avg;
1205 #endif
1206 };
1207 
1208 struct sched_rt_entity {
1209         struct list_head run_list;
1210         unsigned long timeout;
1211         unsigned int time_slice;
1212 
1213         struct sched_rt_entity *back;
1214 #ifdef CONFIG_RT_GROUP_SCHED
1215         struct sched_rt_entity  *parent;
1216         /* rq on which this entity is (to be) queued: */
1217         struct rt_rq            *rt_rq;
1218         /* rq "owned" by this entity/group: */
1219         struct rt_rq            *my_q;
1220 #endif
1221 };
1222 
1223 /*
1224  * default timeslice is 100 msecs (used only for SCHED_RR tasks).
1225  * Timeslices get refilled after they expire.
1226  */
1227 #define RR_TIMESLICE            (100 * HZ / 1000)
1228 
1229 struct rcu_node;
1230 
1231 enum perf_event_task_context {
1232         perf_invalid_context = -1,
1233         perf_hw_context = 0,
1234         perf_sw_context,
1235         perf_nr_task_contexts,
1236 };
1237 
1238 struct task_struct {
1239         volatile long state;    /* -1 unrunnable, 0 runnable, >0 stopped */
1240         void *stack;
1241         atomic_t usage;
1242         unsigned int flags;     /* per process flags, defined below */
1243         unsigned int ptrace;
1244 
1245 #ifdef CONFIG_SMP
1246         struct llist_node wake_entry;
1247         int on_cpu;
1248 #endif
1249         int on_rq;
1250 
1251         int prio, static_prio, normal_prio;
1252         unsigned int rt_priority;
1253         const struct sched_class *sched_class;
1254         struct sched_entity se;
1255         struct sched_rt_entity rt;
1256 #ifdef CONFIG_CGROUP_SCHED
1257         struct task_group *sched_task_group;
1258 #endif
1259 
1260 #ifdef CONFIG_PREEMPT_NOTIFIERS
1261         /* list of struct preempt_notifier: */
1262         struct hlist_head preempt_notifiers;
1263 #endif
1264 
1265         /*
1266          * fpu_counter contains the number of consecutive context switches
1267          * that the FPU is used. If this is over a threshold, the lazy fpu
1268          * saving becomes unlazy to save the trap. This is an unsigned char
1269          * so that after 256 times the counter wraps and the behavior turns
1270          * lazy again; this to deal with bursty apps that only use FPU for
1271          * a short time
1272          */
1273         unsigned char fpu_counter;
1274 #ifdef CONFIG_BLK_DEV_IO_TRACE
1275         unsigned int btrace_seq;
1276 #endif
1277 
1278         unsigned int policy;
1279         int nr_cpus_allowed;
1280         cpumask_t cpus_allowed;
1281 
1282 #ifdef CONFIG_PREEMPT_RCU
1283         int rcu_read_lock_nesting;
1284         char rcu_read_unlock_special;
1285         struct list_head rcu_node_entry;
1286 #endif /* #ifdef CONFIG_PREEMPT_RCU */
1287 #ifdef CONFIG_TREE_PREEMPT_RCU
1288         struct rcu_node *rcu_blocked_node;
1289 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
1290 #ifdef CONFIG_RCU_BOOST
1291         struct rt_mutex *rcu_boost_mutex;
1292 #endif /* #ifdef CONFIG_RCU_BOOST */
1293 
1294 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
1295         struct sched_info sched_info;
1296 #endif
1297 
1298         struct list_head tasks;
1299 #ifdef CONFIG_SMP
1300         struct plist_node pushable_tasks;
1301 #endif
1302 
1303         struct mm_struct *mm, *active_mm;
1304 #ifdef CONFIG_COMPAT_BRK
1305         unsigned brk_randomized:1;
1306 #endif
1307 #if defined(SPLIT_RSS_COUNTING)
1308         struct task_rss_stat    rss_stat;
1309 #endif
1310 /* task state */
1311         int exit_state;
1312         int exit_code, exit_signal;
1313         int pdeath_signal;  /*  The signal sent when the parent dies  */
1314         unsigned int jobctl;    /* JOBCTL_*, siglock protected */
1315         /* ??? */
1316         unsigned int personality;
1317         unsigned did_exec:1;
1318         unsigned in_execve:1;   /* Tell the LSMs that the process is doing an
1319                                  * execve */
1320         unsigned in_iowait:1;
1321 
1322         /* task may not gain privileges */
1323         unsigned no_new_privs:1;
1324 
1325         /* Revert to default priority/policy when forking */
1326         unsigned sched_reset_on_fork:1;
1327         unsigned sched_contributes_to_load:1;
1328 
1329         pid_t pid;
1330         pid_t tgid;
1331 
1332 #ifdef CONFIG_CC_STACKPROTECTOR
1333         /* Canary value for the -fstack-protector gcc feature */
1334         unsigned long stack_canary;
1335 #endif
1336         /*
1337          * pointers to (original) parent process, youngest child, younger sibling,
1338          * older sibling, respectively.  (p->father can be replaced with
1339          * p->real_parent->pid)
1340          */
1341         struct task_struct __rcu *real_parent; /* real parent process */
1342         struct task_struct __rcu *parent; /* recipient of SIGCHLD, wait4() reports */
1343         /*
1344          * children/sibling forms the list of my natural children
1345          */
1346         struct list_head children;      /* list of my children */
1347         struct list_head sibling;       /* linkage in my parent's children list */
1348         struct task_struct *group_leader;       /* threadgroup leader */
1349 
1350         /*
1351          * ptraced is the list of tasks this task is using ptrace on.
1352          * This includes both natural children and PTRACE_ATTACH targets.
1353          * p->ptrace_entry is p's link on the p->parent->ptraced list.
1354          */
1355         struct list_head ptraced;
1356         struct list_head ptrace_entry;
1357 
1358         /* PID/PID hash table linkage. */
1359         struct pid_link pids[PIDTYPE_MAX];
1360         struct list_head thread_group;
1361 
1362         struct completion *vfork_done;          /* for vfork() */
1363         int __user *set_child_tid;              /* CLONE_CHILD_SETTID */
1364         int __user *clear_child_tid;            /* CLONE_CHILD_CLEARTID */
1365 
1366         cputime_t utime, stime, utimescaled, stimescaled;
1367         cputime_t gtime;
1368 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
1369         struct cputime prev_cputime;
1370 #endif
1371         unsigned long nvcsw, nivcsw; /* context switch counts */
1372         struct timespec start_time;             /* monotonic time */
1373         struct timespec real_start_time;        /* boot based time */
1374 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1375         unsigned long min_flt, maj_flt;
1376 
1377         struct task_cputime cputime_expires;
1378         struct list_head cpu_timers[3];
1379 
1380 /* process credentials */
1381         const struct cred __rcu *real_cred; /* objective and real subjective task
1382                                          * credentials (COW) */
1383         const struct cred __rcu *cred;  /* effective (overridable) subjective task
1384                                          * credentials (COW) */
1385         char comm[TASK_COMM_LEN]; /* executable name excluding path
1386                                      - access with [gs]et_task_comm (which lock
1387                                        it with task_lock())
1388                                      - initialized normally by setup_new_exec */
1389 /* file system info */
1390         int link_count, total_link_count;
1391 #ifdef CONFIG_SYSVIPC
1392 /* ipc stuff */
1393         struct sysv_sem sysvsem;
1394 #endif
1395 #ifdef CONFIG_DETECT_HUNG_TASK
1396 /* hung task detection */
1397         unsigned long last_switch_count;
1398 #endif
1399 /* CPU-specific state of this task */
1400         struct thread_struct thread;
1401 /* filesystem information */
1402         struct fs_struct *fs;
1403 /* open file information */
1404         struct files_struct *files;
1405 /* namespaces */
1406         struct nsproxy *nsproxy;
1407 /* signal handlers */
1408         struct signal_struct *signal;
1409         struct sighand_struct *sighand;
1410 
1411         sigset_t blocked, real_blocked;
1412         sigset_t saved_sigmask; /* restored if set_restore_sigmask() was used */
1413         struct sigpending pending;
1414 
1415         unsigned long sas_ss_sp;
1416         size_t sas_ss_size;
1417         int (*notifier)(void *priv);
1418         void *notifier_data;
1419         sigset_t *notifier_mask;
1420         struct callback_head *task_works;
1421 
1422         struct audit_context *audit_context;
1423 #ifdef CONFIG_AUDITSYSCALL
1424         kuid_t loginuid;
1425         unsigned int sessionid;
1426 #endif
1427         struct seccomp seccomp;
1428 
1429 /* Thread group tracking */
1430         u32 parent_exec_id;
1431         u32 self_exec_id;
1432 /* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1433  * mempolicy */
1434         spinlock_t alloc_lock;
1435 
1436         /* Protection of the PI data structures: */
1437         raw_spinlock_t pi_lock;
1438 
1439 #ifdef CONFIG_RT_MUTEXES
1440         /* PI waiters blocked on a rt_mutex held by this task */
1441         struct plist_head pi_waiters;
1442         /* Deadlock detection and priority inheritance handling */
1443         struct rt_mutex_waiter *pi_blocked_on;
1444 #endif
1445 
1446 #ifdef CONFIG_DEBUG_MUTEXES
1447         /* mutex deadlock detection */
1448         struct mutex_waiter *blocked_on;
1449 #endif
1450 #ifdef CONFIG_TRACE_IRQFLAGS
1451         unsigned int irq_events;
1452         unsigned long hardirq_enable_ip;
1453         unsigned long hardirq_disable_ip;
1454         unsigned int hardirq_enable_event;
1455         unsigned int hardirq_disable_event;
1456         int hardirqs_enabled;
1457         int hardirq_context;
1458         unsigned long softirq_disable_ip;
1459         unsigned long softirq_enable_ip;
1460         unsigned int softirq_disable_event;
1461         unsigned int softirq_enable_event;
1462         int softirqs_enabled;
1463         int softirq_context;
1464 #endif
1465 #ifdef CONFIG_LOCKDEP
1466 # define MAX_LOCK_DEPTH 48UL
1467         u64 curr_chain_key;
1468         int lockdep_depth;
1469         unsigned int lockdep_recursion;
1470         struct held_lock held_locks[MAX_LOCK_DEPTH];
1471         gfp_t lockdep_reclaim_gfp;
1472 #endif
1473 
1474 /* journalling filesystem info */
1475         void *journal_info;
1476 
1477 /* stacked block device info */
1478         struct bio_list *bio_list;
1479 
1480 #ifdef CONFIG_BLOCK
1481 /* stack plugging */
1482         struct blk_plug *plug;
1483 #endif
1484 
1485 /* VM state */
1486         struct reclaim_state *reclaim_state;
1487 
1488         struct backing_dev_info *backing_dev_info;
1489 
1490         struct io_context *io_context;
1491 
1492         unsigned long ptrace_message;
1493         siginfo_t *last_siginfo; /* For ptrace use.  */
1494         struct task_io_accounting ioac;
1495 #if defined(CONFIG_TASK_XACCT)
1496         u64 acct_rss_mem1;      /* accumulated rss usage */
1497         u64 acct_vm_mem1;       /* accumulated virtual memory usage */
1498         cputime_t acct_timexpd; /* stime + utime since last update */
1499 #endif
1500 #ifdef CONFIG_CPUSETS
1501         nodemask_t mems_allowed;        /* Protected by alloc_lock */
1502         seqcount_t mems_allowed_seq;    /* Seqence no to catch updates */
1503         int cpuset_mem_spread_rotor;
1504         int cpuset_slab_spread_rotor;
1505 #endif
1506 #ifdef CONFIG_CGROUPS
1507         /* Control Group info protected by css_set_lock */
1508         struct css_set __rcu *cgroups;
1509         /* cg_list protected by css_set_lock and tsk->alloc_lock */
1510         struct list_head cg_list;
1511 #endif
1512 #ifdef CONFIG_FUTEX
1513         struct robust_list_head __user *robust_list;
1514 #ifdef CONFIG_COMPAT
1515         struct compat_robust_list_head __user *compat_robust_list;
1516 #endif
1517         struct list_head pi_state_list;
1518         struct futex_pi_state *pi_state_cache;
1519 #endif
1520 #ifdef CONFIG_PERF_EVENTS
1521         struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1522         struct mutex perf_event_mutex;
1523         struct list_head perf_event_list;
1524 #endif
1525 #ifdef CONFIG_NUMA
1526         struct mempolicy *mempolicy;    /* Protected by alloc_lock */
1527         short il_next;
1528         short pref_node_fork;
1529 #endif
1530 #ifdef CONFIG_NUMA_BALANCING
1531         int numa_scan_seq;
1532         int numa_migrate_seq;
1533         unsigned int numa_scan_period;
1534         u64 node_stamp;                 /* migration stamp  */
1535         struct callback_head numa_work;
1536 #endif /* CONFIG_NUMA_BALANCING */
1537 
1538         struct rcu_head rcu;
1539 
1540         /*
1541          * cache last used pipe for splice
1542          */
1543         struct pipe_inode_info *splice_pipe;
1544 
1545         struct page_frag task_frag;
1546 
1547 #ifdef  CONFIG_TASK_DELAY_ACCT
1548         struct task_delay_info *delays;
1549 #endif
1550 #ifdef CONFIG_FAULT_INJECTION
1551         int make_it_fail;
1552 #endif
1553         /*
1554          * when (nr_dirtied >= nr_dirtied_pause), it's time to call
1555          * balance_dirty_pages() for some dirty throttling pause
1556          */
1557         int nr_dirtied;
1558         int nr_dirtied_pause;
1559         unsigned long dirty_paused_when; /* start of a write-and-pause period */
1560 
1561 #ifdef CONFIG_LATENCYTOP
1562         int latency_record_count;
1563         struct latency_record latency_record[LT_SAVECOUNT];
1564 #endif
1565         /*
1566          * time slack values; these are used to round up poll() and
1567          * select() etc timeout values. These are in nanoseconds.
1568          */
1569         unsigned long timer_slack_ns;
1570         unsigned long default_timer_slack_ns;
1571 
1572 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1573         /* Index of current stored address in ret_stack */
1574         int curr_ret_stack;
1575         /* Stack of return addresses for return function tracing */
1576         struct ftrace_ret_stack *ret_stack;
1577         /* time stamp for last schedule */
1578         unsigned long long ftrace_timestamp;
1579         /*
1580          * Number of functions that haven't been traced
1581          * because of depth overrun.
1582          */
1583         atomic_t trace_overrun;
1584         /* Pause for the tracing */
1585         atomic_t tracing_graph_pause;
1586 #endif
1587 #ifdef CONFIG_TRACING
1588         /* state flags for use by tracers */
1589         unsigned long trace;
1590         /* bitmask and counter of trace recursion */
1591         unsigned long trace_recursion;
1592 #endif /* CONFIG_TRACING */
1593 #ifdef CONFIG_MEMCG /* memcg uses this to do batch job */
1594         struct memcg_batch_info {
1595                 int do_batch;   /* incremented when batch uncharge started */
1596                 struct mem_cgroup *memcg; /* target memcg of uncharge */
1597                 unsigned long nr_pages; /* uncharged usage */
1598                 unsigned long memsw_nr_pages; /* uncharged mem+swap usage */
1599         } memcg_batch;
1600         unsigned int memcg_kmem_skip_account;
1601 #endif
1602 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1603         atomic_t ptrace_bp_refcnt;
1604 #endif
1605 #ifdef CONFIG_UPROBES
1606         struct uprobe_task *utask;
1607 #endif
1608 };
1609 
1610 /* Future-safe accessor for struct task_struct's cpus_allowed. */
1611 #define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
1612 
1613 #ifdef CONFIG_NUMA_BALANCING
1614 extern void task_numa_fault(int node, int pages, bool migrated);
1615 extern void set_numabalancing_state(bool enabled);
1616 #else
1617 static inline void task_numa_fault(int node, int pages, bool migrated)
1618 {
1619 }
1620 static inline void set_numabalancing_state(bool enabled)
1621 {
1622 }
1623 #endif
1624 
1625 /*
1626  * Priority of a process goes from 0..MAX_PRIO-1, valid RT
1627  * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
1628  * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority
1629  * values are inverted: lower p->prio value means higher priority.
1630  *
1631  * The MAX_USER_RT_PRIO value allows the actual maximum
1632  * RT priority to be separate from the value exported to
1633  * user-space.  This allows kernel threads to set their
1634  * priority to a value higher than any user task. Note:
1635  * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
1636  */
1637 
1638 #define MAX_USER_RT_PRIO        100
1639 #define MAX_RT_PRIO             MAX_USER_RT_PRIO
1640 
1641 #define MAX_PRIO                (MAX_RT_PRIO + 40)
1642 #define DEFAULT_PRIO            (MAX_RT_PRIO + 20)
1643 
1644 static inline int rt_prio(int prio)
1645 {
1646         if (unlikely(prio < MAX_RT_PRIO))
1647                 return 1;
1648         return 0;
1649 }
1650 
1651 static inline int rt_task(struct task_struct *p)
1652 {
1653         return rt_prio(p->prio);
1654 }
1655 
1656 static inline struct pid *task_pid(struct task_struct *task)
1657 {
1658         return task->pids[PIDTYPE_PID].pid;
1659 }
1660 
1661 static inline struct pid *task_tgid(struct task_struct *task)
1662 {
1663         return task->group_leader->pids[PIDTYPE_PID].pid;
1664 }
1665 
1666 /*
1667  * Without tasklist or rcu lock it is not safe to dereference
1668  * the result of task_pgrp/task_session even if task == current,
1669  * we can race with another thread doing sys_setsid/sys_setpgid.
1670  */
1671 static inline struct pid *task_pgrp(struct task_struct *task)
1672 {
1673         return task->group_leader->pids[PIDTYPE_PGID].pid;
1674 }
1675 
1676 static inline struct pid *task_session(struct task_struct *task)
1677 {
1678         return task->group_leader->pids[PIDTYPE_SID].pid;
1679 }
1680 
1681 struct pid_namespace;
1682 
1683 /*
1684  * the helpers to get the task's different pids as they are seen
1685  * from various namespaces
1686  *
1687  * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1688  * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1689  *                     current.
1690  * task_xid_nr_ns()  : id seen from the ns specified;
1691  *
1692  * set_task_vxid()   : assigns a virtual id to a task;
1693  *
1694  * see also pid_nr() etc in include/linux/pid.h
1695  */
1696 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
1697                         struct pid_namespace *ns);
1698 
1699 static inline pid_t task_pid_nr(struct task_struct *tsk)
1700 {
1701         return tsk->pid;
1702 }
1703 
1704 static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
1705                                         struct pid_namespace *ns)
1706 {
1707         return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1708 }
1709 
1710 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1711 {
1712         return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1713 }
1714 
1715 
1716 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1717 {
1718         return tsk->tgid;
1719 }
1720 
1721 pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1722 
1723 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1724 {
1725         return pid_vnr(task_tgid(tsk));
1726 }
1727 
1728 
1729 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
1730                                         struct pid_namespace *ns)
1731 {
1732         return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1733 }
1734 
1735 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1736 {
1737         return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1738 }
1739 
1740 
1741 static inline pid_t task_session_nr_ns(struct task_struct *tsk,
1742                                         struct pid_namespace *ns)
1743 {
1744         return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1745 }
1746 
1747 static inline pid_t task_session_vnr(struct task_struct *tsk)
1748 {
1749         return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1750 }
1751 
1752 /* obsolete, do not use */
1753 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1754 {
1755         return task_pgrp_nr_ns(tsk, &init_pid_ns);
1756 }
1757 
1758 /**
1759  * pid_alive - check that a task structure is not stale
1760  * @p: Task structure to be checked.
1761  *
1762  * Test if a process is not yet dead (at most zombie state)
1763  * If pid_alive fails, then pointers within the task structure
1764  * can be stale and must not be dereferenced.
1765  */
1766 static inline int pid_alive(struct task_struct *p)
1767 {
1768         return p->pids[PIDTYPE_PID].pid != NULL;
1769 }
1770 
1771 /**
1772  * is_global_init - check if a task structure is init
1773  * @tsk: Task structure to be checked.
1774  *
1775  * Check if a task structure is the first user space task the kernel created.
1776  */
1777 static inline int is_global_init(struct task_struct *tsk)
1778 {
1779         return tsk->pid == 1;
1780 }
1781 
1782 extern struct pid *cad_pid;
1783 
1784 extern void free_task(struct task_struct *tsk);
1785 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
1786 
1787 extern void __put_task_struct(struct task_struct *t);
1788 
1789 static inline void put_task_struct(struct task_struct *t)
1790 {
1791         if (atomic_dec_and_test(&t->usage))
1792                 __put_task_struct(t);
1793 }
1794 
1795 extern void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
1796 extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
1797 
1798 /*
1799  * Per process flags
1800  */
1801 #define PF_EXITING      0x00000004      /* getting shut down */
1802 #define PF_EXITPIDONE   0x00000008      /* pi exit done on shut down */
1803 #define PF_VCPU         0x00000010      /* I'm a virtual CPU */
1804 #define PF_WQ_WORKER    0x00000020      /* I'm a workqueue worker */
1805 #define PF_FORKNOEXEC   0x00000040      /* forked but didn't exec */
1806 #define PF_MCE_PROCESS  0x00000080      /* process policy on mce errors */
1807 #define PF_SUPERPRIV    0x00000100      /* used super-user privileges */
1808 #define PF_DUMPCORE     0x00000200      /* dumped core */
1809 #define PF_SIGNALED     0x00000400      /* killed by a signal */
1810 #define PF_MEMALLOC     0x00000800      /* Allocating memory */
1811 #define PF_NPROC_EXCEEDED 0x00001000    /* set_user noticed that RLIMIT_NPROC was exceeded */
1812 #define PF_USED_MATH    0x00002000      /* if unset the fpu must be initialized before use */
1813 #define PF_USED_ASYNC   0x00004000      /* used async_schedule*(), used by module init */
1814 #define PF_NOFREEZE     0x00008000      /* this thread should not be frozen */
1815 #define PF_FROZEN       0x00010000      /* frozen for system suspend */
1816 #define PF_FSTRANS      0x00020000      /* inside a filesystem transaction */
1817 #define PF_KSWAPD       0x00040000      /* I am kswapd */
1818 #define PF_LESS_THROTTLE 0x00100000     /* Throttle me less: I clean memory */
1819 #define PF_KTHREAD      0x00200000      /* I am a kernel thread */
1820 #define PF_RANDOMIZE    0x00400000      /* randomize virtual address space */
1821 #define PF_SWAPWRITE    0x00800000      /* Allowed to write to swap */
1822 #define PF_SPREAD_PAGE  0x01000000      /* Spread page cache over cpuset */
1823 #define PF_SPREAD_SLAB  0x02000000      /* Spread some slab caches over cpuset */
1824 #define PF_THREAD_BOUND 0x04000000      /* Thread bound to specific cpu */
1825 #define PF_MCE_EARLY    0x08000000      /* Early kill for mce process policy */
1826 #define PF_MEMPOLICY    0x10000000      /* Non-default NUMA mempolicy */
1827 #define PF_MUTEX_TESTER 0x20000000      /* Thread belongs to the rt mutex tester */
1828 #define PF_FREEZER_SKIP 0x40000000      /* Freezer should not count it as freezable */
1829 
1830 /*
1831  * Only the _current_ task can read/write to tsk->flags, but other
1832  * tasks can access tsk->flags in readonly mode for example
1833  * with tsk_used_math (like during threaded core dumping).
1834  * There is however an exception to this rule during ptrace
1835  * or during fork: the ptracer task is allowed to write to the
1836  * child->flags of its traced child (same goes for fork, the parent
1837  * can write to the child->flags), because we're guaranteed the
1838  * child is not running and in turn not changing child->flags
1839  * at the same time the parent does it.
1840  */
1841 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1842 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1843 #define clear_used_math() clear_stopped_child_used_math(current)
1844 #define set_used_math() set_stopped_child_used_math(current)
1845 #define conditional_stopped_child_used_math(condition, child) \
1846         do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1847 #define conditional_used_math(condition) \
1848         conditional_stopped_child_used_math(condition, current)
1849 #define copy_to_stopped_child_used_math(child) \
1850         do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1851 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1852 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1853 #define used_math() tsk_used_math(current)
1854 
1855 /*
1856  * task->jobctl flags
1857  */
1858 #define JOBCTL_STOP_SIGMASK     0xffff  /* signr of the last group stop */
1859 
1860 #define JOBCTL_STOP_DEQUEUED_BIT 16     /* stop signal dequeued */
1861 #define JOBCTL_STOP_PENDING_BIT 17      /* task should stop for group stop */
1862 #define JOBCTL_STOP_CONSUME_BIT 18      /* consume group stop count */
1863 #define JOBCTL_TRAP_STOP_BIT    19      /* trap for STOP */
1864 #define JOBCTL_TRAP_NOTIFY_BIT  20      /* trap for NOTIFY */
1865 #define JOBCTL_TRAPPING_BIT     21      /* switching to TRACED */
1866 #define JOBCTL_LISTENING_BIT    22      /* ptracer is listening for events */
1867 
1868 #define JOBCTL_STOP_DEQUEUED    (1 << JOBCTL_STOP_DEQUEUED_BIT)
1869 #define JOBCTL_STOP_PENDING     (1 << JOBCTL_STOP_PENDING_BIT)
1870 #define JOBCTL_STOP_CONSUME     (1 << JOBCTL_STOP_CONSUME_BIT)
1871 #define JOBCTL_TRAP_STOP        (1 << JOBCTL_TRAP_STOP_BIT)
1872 #define JOBCTL_TRAP_NOTIFY      (1 << JOBCTL_TRAP_NOTIFY_BIT)
1873 #define JOBCTL_TRAPPING         (1 << JOBCTL_TRAPPING_BIT)
1874 #define JOBCTL_LISTENING        (1 << JOBCTL_LISTENING_BIT)
1875 
1876 #define JOBCTL_TRAP_MASK        (JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
1877 #define JOBCTL_PENDING_MASK     (JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)
1878 
1879 extern bool task_set_jobctl_pending(struct task_struct *task,
1880                                     unsigned int mask);
1881 extern void task_clear_jobctl_trapping(struct task_struct *task);
1882 extern void task_clear_jobctl_pending(struct task_struct *task,
1883                                       unsigned int mask);
1884 
1885 #ifdef CONFIG_PREEMPT_RCU
1886 
1887 #define RCU_READ_UNLOCK_BLOCKED (1 << 0) /* blocked while in RCU read-side. */
1888 #define RCU_READ_UNLOCK_NEED_QS (1 << 1) /* RCU core needs CPU response. */
1889 
1890 static inline void rcu_copy_process(struct task_struct *p)
1891 {
1892         p->rcu_read_lock_nesting = 0;
1893         p->rcu_read_unlock_special = 0;
1894 #ifdef CONFIG_TREE_PREEMPT_RCU
1895         p->rcu_blocked_node = NULL;
1896 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
1897 #ifdef CONFIG_RCU_BOOST
1898         p->rcu_boost_mutex = NULL;
1899 #endif /* #ifdef CONFIG_RCU_BOOST */
1900         INIT_LIST_HEAD(&p->rcu_node_entry);
1901 }
1902 
1903 #else
1904 
1905 static inline void rcu_copy_process(struct task_struct *p)
1906 {
1907 }
1908 
1909 #endif
1910 
1911 static inline void tsk_restore_flags(struct task_struct *task,
1912                                 unsigned long orig_flags, unsigned long flags)
1913 {
1914         task->flags &= ~flags;
1915         task->flags |= orig_flags & flags;
1916 }
1917 
1918 #ifdef CONFIG_SMP
1919 extern void do_set_cpus_allowed(struct task_struct *p,
1920                                const struct cpumask *new_mask);
1921 
1922 extern int set_cpus_allowed_ptr(struct task_struct *p,
1923                                 const struct cpumask *new_mask);
1924 #else
1925 static inline void do_set_cpus_allowed(struct task_struct *p,
1926                                       const struct cpumask *new_mask)
1927 {
1928 }
1929 static inline int set_cpus_allowed_ptr(struct task_struct *p,
1930                                        const struct cpumask *new_mask)
1931 {
1932         if (!cpumask_test_cpu(0, new_mask))
1933                 return -EINVAL;
1934         return 0;
1935 }
1936 #endif
1937 
1938 #ifdef CONFIG_NO_HZ
1939 void calc_load_enter_idle(void);
1940 void calc_load_exit_idle(void);
1941 #else
1942 static inline void calc_load_enter_idle(void) { }
1943 static inline void calc_load_exit_idle(void) { }
1944 #endif /* CONFIG_NO_HZ */
1945 
1946 #ifndef CONFIG_CPUMASK_OFFSTACK
1947 static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
1948 {
1949         return set_cpus_allowed_ptr(p, &new_mask);
1950 }
1951 #endif
1952 
1953 /*
1954  * Do not use outside of architecture code which knows its limitations.
1955  *
1956  * sched_clock() has no promise of monotonicity or bounded drift between
1957  * CPUs, use (which you should not) requires disabling IRQs.
1958  *
1959  * Please use one of the three interfaces below.
1960  */
1961 extern unsigned long long notrace sched_clock(void);
1962 /*
1963  * See the comment in kernel/sched/clock.c
1964  */
1965 extern u64 cpu_clock(int cpu);
1966 extern u64 local_clock(void);
1967 extern u64 sched_clock_cpu(int cpu);
1968 
1969 
1970 extern void sched_clock_init(void);
1971 
1972 #ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
1973 static inline void sched_clock_tick(void)
1974 {
1975 }
1976 
1977 static inline void sched_clock_idle_sleep_event(void)
1978 {
1979 }
1980 
1981 static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
1982 {
1983 }
1984 #else
1985 /*
1986  * Architectures can set this to 1 if they have specified
1987  * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
1988  * but then during bootup it turns out that sched_clock()
1989  * is reliable after all:
1990  */
1991 extern int sched_clock_stable;
1992 
1993 extern void sched_clock_tick(void);
1994 extern void sched_clock_idle_sleep_event(void);
1995 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
1996 #endif
1997 
1998 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
1999 /*
2000  * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
2001  * The reason for this explicit opt-in is not to have perf penalty with
2002  * slow sched_clocks.
2003  */
2004 extern void enable_sched_clock_irqtime(void);
2005 extern void disable_sched_clock_irqtime(void);
2006 #else
2007 static inline void enable_sched_clock_irqtime(void) {}
2008 static inline void disable_sched_clock_irqtime(void) {}
2009 #endif
2010 
2011 extern unsigned long long
2012 task_sched_runtime(struct task_struct *task);
2013 
2014 /* sched_exec is called by processes performing an exec */
2015 #ifdef CONFIG_SMP
2016 extern void sched_exec(void);
2017 #else
2018 #define sched_exec()   {}
2019 #endif
2020 
2021 extern void sched_clock_idle_sleep_event(void);
2022 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2023 
2024 #ifdef CONFIG_HOTPLUG_CPU
2025 extern void idle_task_exit(void);
2026 #else
2027 static inline void idle_task_exit(void) {}
2028 #endif
2029 
2030 #if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP)
2031 extern void wake_up_idle_cpu(int cpu);
2032 #else
2033 static inline void wake_up_idle_cpu(int cpu) { }
2034 #endif
2035 
2036 extern unsigned int sysctl_sched_latency;
2037 extern unsigned int sysctl_sched_min_granularity;
2038 extern unsigned int sysctl_sched_wakeup_granularity;
2039 extern unsigned int sysctl_sched_child_runs_first;
2040 
2041 enum sched_tunable_scaling {
2042         SCHED_TUNABLESCALING_NONE,
2043         SCHED_TUNABLESCALING_LOG,
2044         SCHED_TUNABLESCALING_LINEAR,
2045         SCHED_TUNABLESCALING_END,
2046 };
2047 extern enum sched_tunable_scaling sysctl_sched_tunable_scaling;
2048 
2049 extern unsigned int sysctl_numa_balancing_scan_delay;
2050 extern unsigned int sysctl_numa_balancing_scan_period_min;
2051 extern unsigned int sysctl_numa_balancing_scan_period_max;
2052 extern unsigned int sysctl_numa_balancing_scan_period_reset;
2053 extern unsigned int sysctl_numa_balancing_scan_size;
2054 extern unsigned int sysctl_numa_balancing_settle_count;
2055 
2056 #ifdef CONFIG_SCHED_DEBUG
2057 extern unsigned int sysctl_sched_migration_cost;
2058 extern unsigned int sysctl_sched_nr_migrate;
2059 extern unsigned int sysctl_sched_time_avg;
2060 extern unsigned int sysctl_timer_migration;
2061 extern unsigned int sysctl_sched_shares_window;
2062 
2063 int sched_proc_update_handler(struct ctl_table *table, int write,
2064                 void __user *buffer, size_t *length,
2065                 loff_t *ppos);
2066 #endif
2067 #ifdef CONFIG_SCHED_DEBUG
2068 static inline unsigned int get_sysctl_timer_migration(void)
2069 {
2070         return sysctl_timer_migration;
2071 }
2072 #else
2073 static inline unsigned int get_sysctl_timer_migration(void)
2074 {
2075         return 1;
2076 }
2077 #endif
2078 extern unsigned int sysctl_sched_rt_period;
2079 extern int sysctl_sched_rt_runtime;
2080 
2081 int sched_rt_handler(struct ctl_table *table, int write,
2082                 void __user *buffer, size_t *lenp,
2083                 loff_t *ppos);
2084 
2085 #ifdef CONFIG_SCHED_AUTOGROUP
2086 extern unsigned int sysctl_sched_autogroup_enabled;
2087 
2088 extern void sched_autogroup_create_attach(struct task_struct *p);
2089 extern void sched_autogroup_detach(struct task_struct *p);
2090 extern void sched_autogroup_fork(struct signal_struct *sig);
2091 extern void sched_autogroup_exit(struct signal_struct *sig);
2092 #ifdef CONFIG_PROC_FS
2093 extern void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m);
2094 extern int proc_sched_autogroup_set_nice(struct task_struct *p, int nice);
2095 #endif
2096 #else
2097 static inline void sched_autogroup_create_attach(struct task_struct *p) { }
2098 static inline void sched_autogroup_detach(struct task_struct *p) { }
2099 static inline void sched_autogroup_fork(struct signal_struct *sig) { }
2100 static inline void sched_autogroup_exit(struct signal_struct *sig) { }
2101 #endif
2102 
2103 #ifdef CONFIG_CFS_BANDWIDTH
2104 extern unsigned int sysctl_sched_cfs_bandwidth_slice;
2105 #endif
2106 
2107 #ifdef CONFIG_RT_MUTEXES
2108 extern int rt_mutex_getprio(struct task_struct *p);
2109 extern void rt_mutex_setprio(struct task_struct *p, int prio);
2110 extern void rt_mutex_adjust_pi(struct task_struct *p);
2111 static inline bool tsk_is_pi_blocked(struct task_struct *tsk)
2112 {
2113         return tsk->pi_blocked_on != NULL;
2114 }
2115 #else
2116 static inline int rt_mutex_getprio(struct task_struct *p)
2117 {
2118         return p->normal_prio;
2119 }
2120 # define rt_mutex_adjust_pi(p)          do { } while (0)
2121 static inline bool tsk_is_pi_blocked(struct task_struct *tsk)
2122 {
2123         return false;
2124 }
2125 #endif
2126 
2127 extern bool yield_to(struct task_struct *p, bool preempt);
2128 extern void set_user_nice(struct task_struct *p, long nice);
2129 extern int task_prio(const struct task_struct *p);
2130 extern int task_nice(const struct task_struct *p);
2131 extern int can_nice(const struct task_struct *p, const int nice);
2132 extern int task_curr(const struct task_struct *p);
2133 extern int idle_cpu(int cpu);
2134 extern int sched_setscheduler(struct task_struct *, int,
2135                               const struct sched_param *);
2136 extern int sched_setscheduler_nocheck(struct task_struct *, int,
2137                                       const struct sched_param *);
2138 extern struct task_struct *idle_task(int cpu);
2139 /**
2140  * is_idle_task - is the specified task an idle task?
2141  * @p: the task in question.
2142  */
2143 static inline bool is_idle_task(const struct task_struct *p)
2144 {
2145         return p->pid == 0;
2146 }
2147 extern struct task_struct *curr_task(int cpu);
2148 extern void set_curr_task(int cpu, struct task_struct *p);
2149 
2150 void yield(void);
2151 
2152 /*
2153  * The default (Linux) execution domain.
2154  */
2155 extern struct exec_domain       default_exec_domain;
2156 
2157 union thread_union {
2158         struct thread_info thread_info;
2159         unsigned long stack[THREAD_SIZE/sizeof(long)];
2160 };
2161 
2162 #ifndef __HAVE_ARCH_KSTACK_END
2163 static inline int kstack_end(void *addr)
2164 {
2165         /* Reliable end of stack detection:
2166          * Some APM bios versions misalign the stack
2167          */
2168         return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
2169 }
2170 #endif
2171 
2172 extern union thread_union init_thread_union;
2173 extern struct task_struct init_task;
2174 
2175 extern struct   mm_struct init_mm;
2176 
2177 extern struct pid_namespace init_pid_ns;
2178 
2179 /*
2180  * find a task by one of its numerical ids
2181  *
2182  * find_task_by_pid_ns():
2183  *      finds a task by its pid in the specified namespace
2184  * find_task_by_vpid():
2185  *      finds a task by its virtual pid
2186  *
2187  * see also find_vpid() etc in include/linux/pid.h
2188  */
2189 
2190 extern struct task_struct *find_task_by_vpid(pid_t nr);
2191 extern struct task_struct *find_task_by_pid_ns(pid_t nr,
2192                 struct pid_namespace *ns);
2193 
2194 extern void __set_special_pids(struct pid *pid);
2195 
2196 /* per-UID process charging. */
2197 extern struct user_struct * alloc_uid(kuid_t);
2198 static inline struct user_struct *get_uid(struct user_struct *u)
2199 {
2200         atomic_inc(&u->__count);
2201         return u;
2202 }
2203 extern void free_uid(struct user_struct *);
2204 
2205 #include <asm/current.h>
2206 
2207 extern void xtime_update(unsigned long ticks);
2208 
2209 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2210 extern int wake_up_process(struct task_struct *tsk);
2211 extern void wake_up_new_task(struct task_struct *tsk);
2212 #ifdef CONFIG_SMP
2213  extern void kick_process(struct task_struct *tsk);
2214 #else
2215  static inline void kick_process(struct task_struct *tsk) { }
2216 #endif
2217 extern void sched_fork(struct task_struct *p);
2218 extern void sched_dead(struct task_struct *p);
2219 
2220 extern void proc_caches_init(void);
2221 extern void flush_signals(struct task_struct *);
2222 extern void __flush_signals(struct task_struct *);
2223 extern void ignore_signals(struct task_struct *);
2224 extern void flush_signal_handlers(struct task_struct *, int force_default);
2225 extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
2226 
2227 static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
2228 {
2229         unsigned long flags;
2230         int ret;
2231 
2232         spin_lock_irqsave(&tsk->sighand->siglock, flags);
2233         ret = dequeue_signal(tsk, mask, info);
2234         spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
2235 
2236         return ret;
2237 }
2238 
2239 extern void block_all_signals(int (*notifier)(void *priv), void *priv,
2240                               sigset_t *mask);
2241 extern void unblock_all_signals(void);
2242 extern void release_task(struct task_struct * p);
2243 extern int send_sig_info(int, struct siginfo *, struct task_struct *);
2244 extern int force_sigsegv(int, struct task_struct *);
2245 extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2246 extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
2247 extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2248 extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *,
2249                                 const struct cred *, u32);
2250 extern int kill_pgrp(struct pid *pid, int sig, int priv);
2251 extern int kill_pid(struct pid *pid, int sig, int priv);
2252 extern int kill_proc_info(int, struct siginfo *, pid_t);
2253 extern __must_check bool do_notify_parent(struct task_struct *, int);
2254 extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
2255 extern void force_sig(int, struct task_struct *);
2256 extern int send_sig(int, struct task_struct *, int);
2257 extern int zap_other_threads(struct task_struct *p);
2258 extern struct sigqueue *sigqueue_alloc(void);
2259 extern void sigqueue_free(struct sigqueue *);
2260 extern int send_sigqueue(struct sigqueue *,  struct task_struct *, int group);
2261 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
2262 extern int do_sigaltstack(const stack_t __user *, stack_t __user *, unsigned long);
2263 
2264 static inline void restore_saved_sigmask(void)
2265 {
2266         if (test_and_clear_restore_sigmask())
2267                 __set_current_blocked(&current->saved_sigmask);
2268 }
2269 
2270 static inline sigset_t *sigmask_to_save(void)
2271 {
2272         sigset_t *res = &current->blocked;
2273         if (unlikely(test_restore_sigmask()))
2274                 res = &current->saved_sigmask;
2275         return res;
2276 }
2277 
2278 static inline int kill_cad_pid(int sig, int priv)
2279 {
2280         return kill_pid(cad_pid, sig, priv);
2281 }
2282 
2283 /* These can be the second arg to send_sig_info/send_group_sig_info.  */
2284 #define SEND_SIG_NOINFO ((struct siginfo *) 0)
2285 #define SEND_SIG_PRIV   ((struct siginfo *) 1)
2286 #define SEND_SIG_FORCED ((struct siginfo *) 2)
2287 
2288 /*
2289  * True if we are on the alternate signal stack.
2290  */
2291 static inline int on_sig_stack(unsigned long sp)
2292 {
2293 #ifdef CONFIG_STACK_GROWSUP
2294         return sp >= current->sas_ss_sp &&
2295                 sp - current->sas_ss_sp < current->sas_ss_size;
2296 #else
2297         return sp > current->sas_ss_sp &&
2298                 sp - current->sas_ss_sp <= current->sas_ss_size;
2299 #endif
2300 }
2301 
2302 static inline int sas_ss_flags(unsigned long sp)
2303 {
2304         return (current->sas_ss_size == 0 ? SS_DISABLE
2305                 : on_sig_stack(sp) ? SS_ONSTACK : 0);
2306 }
2307 
2308 /*
2309  * Routines for handling mm_structs
2310  */
2311 extern struct mm_struct * mm_alloc(void);
2312 
2313 /* mmdrop drops the mm and the page tables */
2314 extern void __mmdrop(struct mm_struct *);
2315 static inline void mmdrop(struct mm_struct * mm)
2316 {
2317         if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2318                 __mmdrop(mm);
2319 }
2320 
2321 /* mmput gets rid of the mappings and all user-space */
2322 extern void mmput(struct mm_struct *);
2323 /* Grab a reference to a task's mm, if it is not already going away */
2324 extern struct mm_struct *get_task_mm(struct task_struct *task);
2325 /*
2326  * Grab a reference to a task's mm, if it is not already going away
2327  * and ptrace_may_access with the mode parameter passed to it
2328  * succeeds.
2329  */
2330 extern struct mm_struct *mm_access(struct task_struct *task, unsigned int mode);
2331 /* Remove the current tasks stale references to the old mm_struct */
2332 extern void mm_release(struct task_struct *, struct mm_struct *);
2333 /* Allocate a new mm structure and copy contents from tsk->mm */
2334 extern struct mm_struct *dup_mm(struct task_struct *tsk);
2335 
2336 extern int copy_thread(unsigned long, unsigned long, unsigned long,
2337                         struct task_struct *);
2338 extern void flush_thread(void);
2339 extern void exit_thread(void);
2340 
2341 extern void exit_files(struct task_struct *);
2342 extern void __cleanup_sighand(struct sighand_struct *);
2343 
2344 extern void exit_itimers(struct signal_struct *);
2345 extern void flush_itimer_signals(void);
2346 
2347 extern void do_group_exit(int);
2348 
2349 extern int allow_signal(int);
2350 extern int disallow_signal(int);
2351 
2352 extern int do_execve(const char *,
2353                      const char __user * const __user *,
2354                      const char __user * const __user *);
2355 extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
2356 struct task_struct *fork_idle(int);
2357 extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
2358 
2359 extern void set_task_comm(struct task_struct *tsk, char *from);
2360 extern char *get_task_comm(char *to, struct task_struct *tsk);
2361 
2362 #ifdef CONFIG_SMP
2363 void scheduler_ipi(void);
2364 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
2365 #else
2366 static inline void scheduler_ipi(void) { }
2367 static inline unsigned long wait_task_inactive(struct task_struct *p,
2368                                                long match_state)
2369 {
2370         return 1;
2371 }
2372 #endif
2373 
2374 #define next_task(p) \
2375         list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
2376 
2377 #define for_each_process(p) \
2378         for (p = &init_task ; (p = next_task(p)) != &init_task ; )
2379 
2380 extern bool current_is_single_threaded(void);
2381 
2382 /*
2383  * Careful: do_each_thread/while_each_thread is a double loop so
2384  *          'break' will not work as expected - use goto instead.
2385  */
2386 #define do_each_thread(g, t) \
2387         for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
2388 
2389 #define while_each_thread(g, t) \
2390         while ((t = next_thread(t)) != g)
2391 
2392 static inline int get_nr_threads(struct task_struct *tsk)
2393 {
2394         return tsk->signal->nr_threads;
2395 }
2396 
2397 static inline bool thread_group_leader(struct task_struct *p)
2398 {
2399         return p->exit_signal >= 0;
2400 }
2401 
2402 /* Do to the insanities of de_thread it is possible for a process
2403  * to have the pid of the thread group leader without actually being
2404  * the thread group leader.  For iteration through the pids in proc
2405  * all we care about is that we have a task with the appropriate
2406  * pid, we don't actually care if we have the right task.
2407  */
2408 static inline int has_group_leader_pid(struct task_struct *p)
2409 {
2410         return p->pid == p->tgid;
2411 }
2412 
2413 static inline
2414 int same_thread_group(struct task_struct *p1, struct task_struct *p2)
2415 {
2416         return p1->tgid == p2->tgid;
2417 }
2418 
2419 static inline struct task_struct *next_thread(const struct task_struct *p)
2420 {
2421         return list_entry_rcu(p->thread_group.next,
2422                               struct task_struct, thread_group);
2423 }
2424 
2425 static inline int thread_group_empty(struct task_struct *p)
2426 {
2427         return list_empty(&p->thread_group);
2428 }
2429 
2430 #define delay_group_leader(p) \
2431                 (thread_group_leader(p) && !thread_group_empty(p))
2432 
2433 /*
2434  * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
2435  * subscriptions and synchronises with wait4().  Also used in procfs.  Also
2436  * pins the final release of task.io_context.  Also protects ->cpuset and
2437  * ->cgroup.subsys[]. And ->vfork_done.
2438  *
2439  * Nests both inside and outside of read_lock(&tasklist_lock).
2440  * It must not be nested with write_lock_irq(&tasklist_lock),
2441  * neither inside nor outside.
2442  */
2443 static inline void task_lock(struct task_struct *p)
2444 {
2445         spin_lock(&p->alloc_lock);
2446 }
2447 
2448 static inline void task_unlock(struct task_struct *p)
2449 {
2450         spin_unlock(&p->alloc_lock);
2451 }
2452 
2453 extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
2454                                                         unsigned long *flags);
2455 
2456 static inline struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
2457                                                        unsigned long *flags)
2458 {
2459         struct sighand_struct *ret;
2460 
2461         ret = __lock_task_sighand(tsk, flags);
2462         (void)__cond_lock(&tsk->sighand->siglock, ret);
2463         return ret;
2464 }
2465 
2466 static inline void unlock_task_sighand(struct task_struct *tsk,
2467                                                 unsigned long *flags)
2468 {
2469         spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
2470 }
2471 
2472 #ifdef CONFIG_CGROUPS
2473 static inline void threadgroup_change_begin(struct task_struct *tsk)
2474 {
2475         down_read(&tsk->signal->group_rwsem);
2476 }
2477 static inline void threadgroup_change_end(struct task_struct *tsk)
2478 {
2479         up_read(&tsk->signal->group_rwsem);
2480 }
2481 
2482 /**
2483  * threadgroup_lock - lock threadgroup
2484  * @tsk: member task of the threadgroup to lock
2485  *
2486  * Lock the threadgroup @tsk belongs to.  No new task is allowed to enter
2487  * and member tasks aren't allowed to exit (as indicated by PF_EXITING) or
2488  * perform exec.  This is useful for cases where the threadgroup needs to
2489  * stay stable across blockable operations.
2490  *
2491  * fork and exit paths explicitly call threadgroup_change_{begin|end}() for
2492  * synchronization.  While held, no new task will be added to threadgroup
2493  * and no existing live task will have its PF_EXITING set.
2494  *
2495  * During exec, a task goes and puts its thread group through unusual
2496  * changes.  After de-threading, exclusive access is assumed to resources
2497  * which are usually shared by tasks in the same group - e.g. sighand may
2498  * be replaced with a new one.  Also, the exec'ing task takes over group
2499  * leader role including its pid.  Exclude these changes while locked by
2500  * grabbing cred_guard_mutex which is used to synchronize exec path.
2501  */
2502 static inline void threadgroup_lock(struct task_struct *tsk)
2503 {
2504         /*
2505          * exec uses exit for de-threading nesting group_rwsem inside
2506          * cred_guard_mutex. Grab cred_guard_mutex first.
2507          */
2508         mutex_lock(&tsk->signal->cred_guard_mutex);
2509         down_write(&tsk->signal->group_rwsem);
2510 }
2511 
2512 /**
2513  * threadgroup_unlock - unlock threadgroup
2514  * @tsk: member task of the threadgroup to unlock
2515  *
2516  * Reverse threadgroup_lock().
2517  */
2518 static inline void threadgroup_unlock(struct task_struct *tsk)
2519 {
2520         up_write(&tsk->signal->group_rwsem);
2521         mutex_unlock(&tsk->signal->cred_guard_mutex);
2522 }
2523 #else
2524 static inline void threadgroup_change_begin(struct task_struct *tsk) {}
2525 static inline void threadgroup_change_end(struct task_struct *tsk) {}
2526 static inline void threadgroup_lock(struct task_struct *tsk) {}
2527 static inline void threadgroup_unlock(struct task_struct *tsk) {}
2528 #endif
2529 
2530 #ifndef __HAVE_THREAD_FUNCTIONS
2531 
2532 #define task_thread_info(task)  ((struct thread_info *)(task)->stack)
2533 #define task_stack_page(task)   ((task)->stack)
2534 
2535 static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
2536 {
2537         *task_thread_info(p) = *task_thread_info(org);
2538         task_thread_info(p)->task = p;
2539 }
2540 
2541 static inline unsigned long *end_of_stack(struct task_struct *p)
2542 {
2543         return (unsigned long *)(task_thread_info(p) + 1);
2544 }
2545 
2546 #endif
2547 
2548 static inline int object_is_on_stack(void *obj)
2549 {
2550         void *stack = task_stack_page(current);
2551 
2552         return (obj >= stack) && (obj < (stack + THREAD_SIZE));
2553 }
2554 
2555 extern void thread_info_cache_init(void);
2556 
2557 #ifdef CONFIG_DEBUG_STACK_USAGE
2558 static inline unsigned long stack_not_used(struct task_struct *p)
2559 {
2560         unsigned long *n = end_of_stack(p);
2561 
2562         do {    /* Skip over canary */
2563                 n++;
2564         } while (!*n);
2565 
2566         return (unsigned long)n - (unsigned long)end_of_stack(p);
2567 }
2568 #endif
2569 
2570 /* set thread flags in other task's structures
2571  * - see asm/thread_info.h for TIF_xxxx flags available
2572  */
2573 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2574 {
2575         set_ti_thread_flag(task_thread_info(tsk), flag);
2576 }
2577 
2578 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2579 {
2580         clear_ti_thread_flag(task_thread_info(tsk), flag);
2581 }
2582 
2583 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2584 {
2585         return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2586 }
2587 
2588 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2589 {
2590         return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2591 }
2592 
2593 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2594 {
2595         return test_ti_thread_flag(task_thread_info(tsk), flag);
2596 }
2597 
2598 static inline void set_tsk_need_resched(struct task_struct *tsk)
2599 {
2600         set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2601 }
2602 
2603 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2604 {
2605         clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2606 }
2607 
2608 static inline int test_tsk_need_resched(struct task_struct *tsk)
2609 {
2610         return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2611 }
2612 
2613 static inline int restart_syscall(void)
2614 {
2615         set_tsk_thread_flag(current, TIF_SIGPENDING);
2616         return -ERESTARTNOINTR;
2617 }
2618 
2619 static inline int signal_pending(struct task_struct *p)
2620 {
2621         return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
2622 }
2623 
2624 static inline int __fatal_signal_pending(struct task_struct *p)
2625 {
2626         return unlikely(sigismember(&p->pending.signal, SIGKILL));
2627 }
2628 
2629 static inline int fatal_signal_pending(struct task_struct *p)
2630 {
2631         return signal_pending(p) && __fatal_signal_pending(p);
2632 }
2633 
2634 static inline int signal_pending_state(long state, struct task_struct *p)
2635 {
2636         if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
2637                 return 0;
2638         if (!signal_pending(p))
2639                 return 0;
2640 
2641         return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
2642 }
2643 
2644 static inline int need_resched(void)
2645 {
2646         return unlikely(test_thread_flag(TIF_NEED_RESCHED));
2647 }
2648 
2649 /*
2650  * cond_resched() and cond_resched_lock(): latency reduction via
2651  * explicit rescheduling in places that are safe. The return
2652  * value indicates whether a reschedule was done in fact.
2653  * cond_resched_lock() will drop the spinlock before scheduling,
2654  * cond_resched_softirq() will enable bhs before scheduling.
2655  */
2656 extern int _cond_resched(void);
2657 
2658 #define cond_resched() ({                       \
2659         __might_sleep(__FILE__, __LINE__, 0);   \
2660         _cond_resched();                        \
2661 })
2662 
2663 extern int __cond_resched_lock(spinlock_t *lock);
2664 
2665 #ifdef CONFIG_PREEMPT_COUNT
2666 #define PREEMPT_LOCK_OFFSET     PREEMPT_OFFSET
2667 #else
2668 #define PREEMPT_LOCK_OFFSET     0
2669 #endif
2670 
2671 #define cond_resched_lock(lock) ({                              \
2672         __might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET); \
2673         __cond_resched_lock(lock);                              \
2674 })
2675 
2676 extern int __cond_resched_softirq(void);
2677 
2678 #define cond_resched_softirq() ({                                       \
2679         __might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET);      \
2680         __cond_resched_softirq();                                       \
2681 })
2682 
2683 /*
2684  * Does a critical section need to be broken due to another
2685  * task waiting?: (technically does not depend on CONFIG_PREEMPT,
2686  * but a general need for low latency)
2687  */
2688 static inline int spin_needbreak(spinlock_t *lock)
2689 {
2690 #ifdef CONFIG_PREEMPT
2691         return spin_is_contended(lock);
2692 #else
2693         return 0;
2694 #endif
2695 }
2696 
2697 /*
2698  * Thread group CPU time accounting.
2699  */
2700 void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
2701 void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
2702 
2703 static inline void thread_group_cputime_init(struct signal_struct *sig)
2704 {
2705         raw_spin_lock_init(&sig->cputimer.lock);
2706 }
2707 
2708 /*
2709  * Reevaluate whether the task has signals pending delivery.
2710  * Wake the task if so.
2711  * This is required every time the blocked sigset_t changes.
2712  * callers must hold sighand->siglock.
2713  */
2714 extern void recalc_sigpending_and_wake(struct task_struct *t);
2715 extern void recalc_sigpending(void);
2716 
2717 extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
2718 
2719 static inline void signal_wake_up(struct task_struct *t, bool resume)
2720 {
2721         signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0);
2722 }
2723 static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
2724 {
2725         signal_wake_up_state(t, resume ? __TASK_TRACED : 0);
2726 }
2727 
2728 /*
2729  * Wrappers for p->thread_info->cpu access. No-op on UP.
2730  */
2731 #ifdef CONFIG_SMP
2732 
2733 static inline unsigned int task_cpu(const struct task_struct *p)
2734 {
2735         return task_thread_info(p)->cpu;
2736 }
2737 
2738 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2739 
2740 #else
2741 
2742 static inline unsigned int task_cpu(const struct task_struct *p)
2743 {
2744         return 0;
2745 }
2746 
2747 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2748 {
2749 }
2750 
2751 #endif /* CONFIG_SMP */
2752 
2753 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2754 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2755 
2756 extern void normalize_rt_tasks(void);
2757 
2758 #ifdef CONFIG_CGROUP_SCHED
2759 
2760 extern struct task_group root_task_group;
2761 
2762 extern struct task_group *sched_create_group(struct task_group *parent);
2763 extern void sched_destroy_group(struct task_group *tg);
2764 extern void sched_move_task(struct task_struct *tsk);
2765 #ifdef CONFIG_FAIR_GROUP_SCHED
2766 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
2767 extern unsigned long sched_group_shares(struct task_group *tg);
2768 #endif
2769 #ifdef CONFIG_RT_GROUP_SCHED
2770 extern int sched_group_set_rt_runtime(struct task_group *tg,
2771                                       long rt_runtime_us);
2772 extern long sched_group_rt_runtime(struct task_group *tg);
2773 extern int sched_group_set_rt_period(struct task_group *tg,
2774                                       long rt_period_us);
2775 extern long sched_group_rt_period(struct task_group *tg);
2776 extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk);
2777 #endif
2778 #endif /* CONFIG_CGROUP_SCHED */
2779 
2780 extern int task_can_switch_user(struct user_struct *up,
2781                                         struct task_struct *tsk);
2782 
2783 #ifdef CONFIG_TASK_XACCT
2784 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2785 {
2786         tsk->ioac.rchar += amt;
2787 }
2788 
2789 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2790 {
2791         tsk->ioac.wchar += amt;
2792 }
2793 
2794 static inline void inc_syscr(struct task_struct *tsk)
2795 {
2796         tsk->ioac.syscr++;
2797 }
2798 
2799 static inline void inc_syscw(struct task_struct *tsk)
2800 {
2801         tsk->ioac.syscw++;
2802 }
2803 #else
2804 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2805 {
2806 }
2807 
2808 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2809 {
2810 }
2811 
2812 static inline void inc_syscr(struct task_struct *tsk)
2813 {
2814 }
2815 
2816 static inline void inc_syscw(struct task_struct *tsk)
2817 {
2818 }
2819 #endif
2820 
2821 #ifndef TASK_SIZE_OF
2822 #define TASK_SIZE_OF(tsk)       TASK_SIZE
2823 #endif
2824 
2825 #ifdef CONFIG_MM_OWNER
2826 extern void mm_update_next_owner(struct mm_struct *mm);
2827 extern void mm_init_owner(struct mm_struct *mm, struct task_struct *p);
2828 #else
2829 static inline void mm_update_next_owner(struct mm_struct *mm)
2830 {
2831 }
2832 
2833 static inline void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
2834 {
2835 }
2836 #endif /* CONFIG_MM_OWNER */
2837 
2838 static inline unsigned long task_rlimit(const struct task_struct *tsk,
2839                 unsigned int limit)
2840 {
2841         return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_cur);
2842 }
2843 
2844 static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
2845                 unsigned int limit)
2846 {
2847         return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_max);
2848 }
2849 
2850 static inline unsigned long rlimit(unsigned int limit)
2851 {
2852         return task_rlimit(current, limit);
2853 }
2854 
2855 static inline unsigned long rlimit_max(unsigned int limit)
2856 {
2857         return task_rlimit_max(current, limit);
2858 }
2859 
2860 #endif
2861 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us