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