linux/include/linux/sched.h
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   1#ifndef _LINUX_SCHED_H
   2#define _LINUX_SCHED_H
   3
   4/*
   5 * cloning flags:
   6 */
   7#define CSIGNAL         0x000000ff      /* signal mask to be sent at exit */
   8#define CLONE_VM        0x00000100      /* set if VM shared between processes */
   9#define CLONE_FS        0x00000200      /* set if fs info shared between processes */
  10#define CLONE_FILES     0x00000400      /* set if open files shared between processes */
  11#define CLONE_SIGHAND   0x00000800      /* set if signal handlers and blocked signals shared */
  12#define CLONE_PTRACE    0x00002000      /* set if we want to let tracing continue on the child too */
  13#define CLONE_VFORK     0x00004000      /* set if the parent wants the child to wake it up on mm_release */
  14#define CLONE_PARENT    0x00008000      /* set if we want to have the same parent as the cloner */
  15#define CLONE_THREAD    0x00010000      /* Same thread group? */
  16#define CLONE_NEWNS     0x00020000      /* New namespace group? */
  17#define CLONE_SYSVSEM   0x00040000      /* share system V SEM_UNDO semantics */
  18#define CLONE_SETTLS    0x00080000      /* create a new TLS for the child */
  19#define CLONE_PARENT_SETTID     0x00100000      /* set the TID in the parent */
  20#define CLONE_CHILD_CLEARTID    0x00200000      /* clear the TID in the child */
  21#define CLONE_DETACHED          0x00400000      /* Unused, ignored */
  22#define CLONE_UNTRACED          0x00800000      /* set if the tracing process can't force CLONE_PTRACE on this clone */
  23#define CLONE_CHILD_SETTID      0x01000000      /* set the TID in the child */
  24#define CLONE_STOPPED           0x02000000      /* Start in stopped state */
  25#define CLONE_NEWUTS            0x04000000      /* New utsname group? */
  26#define CLONE_NEWIPC            0x08000000      /* New ipcs */
  27#define CLONE_NEWUSER           0x10000000      /* New user namespace */
  28#define CLONE_NEWPID            0x20000000      /* New pid namespace */
  29#define CLONE_NEWNET            0x40000000      /* New network namespace */
  30#define CLONE_IO                0x80000000      /* Clone io context */
  31
  32/*
  33 * Scheduling policies
  34 */
  35#define SCHED_NORMAL            0
  36#define SCHED_FIFO              1
  37#define SCHED_RR                2
  38#define SCHED_BATCH             3
  39/* SCHED_ISO: reserved but not implemented yet */
  40#define SCHED_IDLE              5
  41
  42#ifdef __KERNEL__
  43
  44struct sched_param {
  45        int sched_priority;
  46};
  47
  48#include <asm/param.h>  /* for HZ */
  49
  50#include <linux/capability.h>
  51#include <linux/threads.h>
  52#include <linux/kernel.h>
  53#include <linux/types.h>
  54#include <linux/timex.h>
  55#include <linux/jiffies.h>
  56#include <linux/rbtree.h>
  57#include <linux/thread_info.h>
  58#include <linux/cpumask.h>
  59#include <linux/errno.h>
  60#include <linux/nodemask.h>
  61#include <linux/mm_types.h>
  62
  63#include <asm/system.h>
  64#include <asm/page.h>
  65#include <asm/ptrace.h>
  66#include <asm/cputime.h>
  67
  68#include <linux/smp.h>
  69#include <linux/sem.h>
  70#include <linux/signal.h>
  71#include <linux/fs_struct.h>
  72#include <linux/compiler.h>
  73#include <linux/completion.h>
  74#include <linux/pid.h>
  75#include <linux/percpu.h>
  76#include <linux/topology.h>
  77#include <linux/proportions.h>
  78#include <linux/seccomp.h>
  79#include <linux/rcupdate.h>
  80#include <linux/rtmutex.h>
  81
  82#include <linux/time.h>
  83#include <linux/param.h>
  84#include <linux/resource.h>
  85#include <linux/timer.h>
  86#include <linux/hrtimer.h>
  87#include <linux/task_io_accounting.h>
  88#include <linux/kobject.h>
  89#include <linux/latencytop.h>
  90#include <linux/cred.h>
  91
  92#include <asm/processor.h>
  93
  94struct mem_cgroup;
  95struct exec_domain;
  96struct futex_pi_state;
  97struct robust_list_head;
  98struct bio;
  99struct bts_tracer;
 100
 101/*
 102 * List of flags we want to share for kernel threads,
 103 * if only because they are not used by them anyway.
 104 */
 105#define CLONE_KERNEL    (CLONE_FS | CLONE_FILES | CLONE_SIGHAND)
 106
 107/*
 108 * These are the constant used to fake the fixed-point load-average
 109 * counting. Some notes:
 110 *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
 111 *    a load-average precision of 10 bits integer + 11 bits fractional
 112 *  - if you want to count load-averages more often, you need more
 113 *    precision, or rounding will get you. With 2-second counting freq,
 114 *    the EXP_n values would be 1981, 2034 and 2043 if still using only
 115 *    11 bit fractions.
 116 */
 117extern unsigned long avenrun[];         /* Load averages */
 118
 119#define FSHIFT          11              /* nr of bits of precision */
 120#define FIXED_1         (1<<FSHIFT)     /* 1.0 as fixed-point */
 121#define LOAD_FREQ       (5*HZ+1)        /* 5 sec intervals */
 122#define EXP_1           1884            /* 1/exp(5sec/1min) as fixed-point */
 123#define EXP_5           2014            /* 1/exp(5sec/5min) */
 124#define EXP_15          2037            /* 1/exp(5sec/15min) */
 125
 126#define CALC_LOAD(load,exp,n) \
 127        load *= exp; \
 128        load += n*(FIXED_1-exp); \
 129        load >>= FSHIFT;
 130
 131extern unsigned long total_forks;
 132extern int nr_threads;
 133DECLARE_PER_CPU(unsigned long, process_counts);
 134extern int nr_processes(void);
 135extern unsigned long nr_running(void);
 136extern unsigned long nr_uninterruptible(void);
 137extern unsigned long nr_active(void);
 138extern unsigned long nr_iowait(void);
 139
 140struct seq_file;
 141struct cfs_rq;
 142struct task_group;
 143#ifdef CONFIG_SCHED_DEBUG
 144extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
 145extern void proc_sched_set_task(struct task_struct *p);
 146extern void
 147print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
 148#else
 149static inline void
 150proc_sched_show_task(struct task_struct *p, struct seq_file *m)
 151{
 152}
 153static inline void proc_sched_set_task(struct task_struct *p)
 154{
 155}
 156static inline void
 157print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
 158{
 159}
 160#endif
 161
 162extern unsigned long long time_sync_thresh;
 163
 164/*
 165 * Task state bitmask. NOTE! These bits are also
 166 * encoded in fs/proc/array.c: get_task_state().
 167 *
 168 * We have two separate sets of flags: task->state
 169 * is about runnability, while task->exit_state are
 170 * about the task exiting. Confusing, but this way
 171 * modifying one set can't modify the other one by
 172 * mistake.
 173 */
 174#define TASK_RUNNING            0
 175#define TASK_INTERRUPTIBLE      1
 176#define TASK_UNINTERRUPTIBLE    2
 177#define __TASK_STOPPED          4
 178#define __TASK_TRACED           8
 179/* in tsk->exit_state */
 180#define EXIT_ZOMBIE             16
 181#define EXIT_DEAD               32
 182/* in tsk->state again */
 183#define TASK_DEAD               64
 184#define TASK_WAKEKILL           128
 185
 186/* Convenience macros for the sake of set_task_state */
 187#define TASK_KILLABLE           (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
 188#define TASK_STOPPED            (TASK_WAKEKILL | __TASK_STOPPED)
 189#define TASK_TRACED             (TASK_WAKEKILL | __TASK_TRACED)
 190
 191/* Convenience macros for the sake of wake_up */
 192#define TASK_NORMAL             (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
 193#define TASK_ALL                (TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
 194
 195/* get_task_state() */
 196#define TASK_REPORT             (TASK_RUNNING | TASK_INTERRUPTIBLE | \
 197                                 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
 198                                 __TASK_TRACED)
 199
 200#define task_is_traced(task)    ((task->state & __TASK_TRACED) != 0)
 201#define task_is_stopped(task)   ((task->state & __TASK_STOPPED) != 0)
 202#define task_is_stopped_or_traced(task) \
 203                        ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
 204#define task_contributes_to_load(task)  \
 205                                ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
 206                                 (task->flags & PF_FROZEN) == 0)
 207
 208#define __set_task_state(tsk, state_value)              \
 209        do { (tsk)->state = (state_value); } while (0)
 210#define set_task_state(tsk, state_value)                \
 211        set_mb((tsk)->state, (state_value))
 212
 213/*
 214 * set_current_state() includes a barrier so that the write of current->state
 215 * is correctly serialised wrt the caller's subsequent test of whether to
 216 * actually sleep:
 217 *
 218 *      set_current_state(TASK_UNINTERRUPTIBLE);
 219 *      if (do_i_need_to_sleep())
 220 *              schedule();
 221 *
 222 * If the caller does not need such serialisation then use __set_current_state()
 223 */
 224#define __set_current_state(state_value)                        \
 225        do { current->state = (state_value); } while (0)
 226#define set_current_state(state_value)          \
 227        set_mb(current->state, (state_value))
 228
 229/* Task command name length */
 230#define TASK_COMM_LEN 16
 231
 232#include <linux/spinlock.h>
 233
 234/*
 235 * This serializes "schedule()" and also protects
 236 * the run-queue from deletions/modifications (but
 237 * _adding_ to the beginning of the run-queue has
 238 * a separate lock).
 239 */
 240extern rwlock_t tasklist_lock;
 241extern spinlock_t mmlist_lock;
 242
 243struct task_struct;
 244
 245extern void sched_init(void);
 246extern void sched_init_smp(void);
 247extern asmlinkage void schedule_tail(struct task_struct *prev);
 248extern void init_idle(struct task_struct *idle, int cpu);
 249extern void init_idle_bootup_task(struct task_struct *idle);
 250
 251extern int runqueue_is_locked(void);
 252extern void task_rq_unlock_wait(struct task_struct *p);
 253
 254extern cpumask_var_t nohz_cpu_mask;
 255#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ)
 256extern int select_nohz_load_balancer(int cpu);
 257#else
 258static inline int select_nohz_load_balancer(int cpu)
 259{
 260        return 0;
 261}
 262#endif
 263
 264/*
 265 * Only dump TASK_* tasks. (0 for all tasks)
 266 */
 267extern void show_state_filter(unsigned long state_filter);
 268
 269static inline void show_state(void)
 270{
 271        show_state_filter(0);
 272}
 273
 274extern void show_regs(struct pt_regs *);
 275
 276/*
 277 * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
 278 * task), SP is the stack pointer of the first frame that should be shown in the back
 279 * trace (or NULL if the entire call-chain of the task should be shown).
 280 */
 281extern void show_stack(struct task_struct *task, unsigned long *sp);
 282
 283void io_schedule(void);
 284long io_schedule_timeout(long timeout);
 285
 286extern void cpu_init (void);
 287extern void trap_init(void);
 288extern void update_process_times(int user);
 289extern void scheduler_tick(void);
 290
 291extern void sched_show_task(struct task_struct *p);
 292
 293#ifdef CONFIG_DETECT_SOFTLOCKUP
 294extern void softlockup_tick(void);
 295extern void touch_softlockup_watchdog(void);
 296extern void touch_all_softlockup_watchdogs(void);
 297extern int proc_dosoftlockup_thresh(struct ctl_table *table, int write,
 298                                    struct file *filp, void __user *buffer,
 299                                    size_t *lenp, loff_t *ppos);
 300extern unsigned int  softlockup_panic;
 301extern unsigned long sysctl_hung_task_check_count;
 302extern unsigned long sysctl_hung_task_timeout_secs;
 303extern unsigned long sysctl_hung_task_warnings;
 304extern int softlockup_thresh;
 305#else
 306static inline void softlockup_tick(void)
 307{
 308}
 309static inline void spawn_softlockup_task(void)
 310{
 311}
 312static inline void touch_softlockup_watchdog(void)
 313{
 314}
 315static inline void touch_all_softlockup_watchdogs(void)
 316{
 317}
 318#endif
 319
 320
 321/* Attach to any functions which should be ignored in wchan output. */
 322#define __sched         __attribute__((__section__(".sched.text")))
 323
 324/* Linker adds these: start and end of __sched functions */
 325extern char __sched_text_start[], __sched_text_end[];
 326
 327/* Is this address in the __sched functions? */
 328extern int in_sched_functions(unsigned long addr);
 329
 330#define MAX_SCHEDULE_TIMEOUT    LONG_MAX
 331extern signed long schedule_timeout(signed long timeout);
 332extern signed long schedule_timeout_interruptible(signed long timeout);
 333extern signed long schedule_timeout_killable(signed long timeout);
 334extern signed long schedule_timeout_uninterruptible(signed long timeout);
 335asmlinkage void schedule(void);
 336
 337struct nsproxy;
 338struct user_namespace;
 339
 340/* Maximum number of active map areas.. This is a random (large) number */
 341#define DEFAULT_MAX_MAP_COUNT   65536
 342
 343extern int sysctl_max_map_count;
 344
 345#include <linux/aio.h>
 346
 347extern unsigned long
 348arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
 349                       unsigned long, unsigned long);
 350extern unsigned long
 351arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
 352                          unsigned long len, unsigned long pgoff,
 353                          unsigned long flags);
 354extern void arch_unmap_area(struct mm_struct *, unsigned long);
 355extern void arch_unmap_area_topdown(struct mm_struct *, unsigned long);
 356
 357#if USE_SPLIT_PTLOCKS
 358/*
 359 * The mm counters are not protected by its page_table_lock,
 360 * so must be incremented atomically.
 361 */
 362#define set_mm_counter(mm, member, value) atomic_long_set(&(mm)->_##member, value)
 363#define get_mm_counter(mm, member) ((unsigned long)atomic_long_read(&(mm)->_##member))
 364#define add_mm_counter(mm, member, value) atomic_long_add(value, &(mm)->_##member)
 365#define inc_mm_counter(mm, member) atomic_long_inc(&(mm)->_##member)
 366#define dec_mm_counter(mm, member) atomic_long_dec(&(mm)->_##member)
 367
 368#else  /* !USE_SPLIT_PTLOCKS */
 369/*
 370 * The mm counters are protected by its page_table_lock,
 371 * so can be incremented directly.
 372 */
 373#define set_mm_counter(mm, member, value) (mm)->_##member = (value)
 374#define get_mm_counter(mm, member) ((mm)->_##member)
 375#define add_mm_counter(mm, member, value) (mm)->_##member += (value)
 376#define inc_mm_counter(mm, member) (mm)->_##member++
 377#define dec_mm_counter(mm, member) (mm)->_##member--
 378
 379#endif /* !USE_SPLIT_PTLOCKS */
 380
 381#define get_mm_rss(mm)                                  \
 382        (get_mm_counter(mm, file_rss) + get_mm_counter(mm, anon_rss))
 383#define update_hiwater_rss(mm)  do {                    \
 384        unsigned long _rss = get_mm_rss(mm);            \
 385        if ((mm)->hiwater_rss < _rss)                   \
 386                (mm)->hiwater_rss = _rss;               \
 387} while (0)
 388#define update_hiwater_vm(mm)   do {                    \
 389        if ((mm)->hiwater_vm < (mm)->total_vm)          \
 390                (mm)->hiwater_vm = (mm)->total_vm;      \
 391} while (0)
 392
 393#define get_mm_hiwater_rss(mm)  max((mm)->hiwater_rss, get_mm_rss(mm))
 394#define get_mm_hiwater_vm(mm)   max((mm)->hiwater_vm, (mm)->total_vm)
 395
 396extern void set_dumpable(struct mm_struct *mm, int value);
 397extern int get_dumpable(struct mm_struct *mm);
 398
 399/* mm flags */
 400/* dumpable bits */
 401#define MMF_DUMPABLE      0  /* core dump is permitted */
 402#define MMF_DUMP_SECURELY 1  /* core file is readable only by root */
 403#define MMF_DUMPABLE_BITS 2
 404
 405/* coredump filter bits */
 406#define MMF_DUMP_ANON_PRIVATE   2
 407#define MMF_DUMP_ANON_SHARED    3
 408#define MMF_DUMP_MAPPED_PRIVATE 4
 409#define MMF_DUMP_MAPPED_SHARED  5
 410#define MMF_DUMP_ELF_HEADERS    6
 411#define MMF_DUMP_HUGETLB_PRIVATE 7
 412#define MMF_DUMP_HUGETLB_SHARED  8
 413#define MMF_DUMP_FILTER_SHIFT   MMF_DUMPABLE_BITS
 414#define MMF_DUMP_FILTER_BITS    7
 415#define MMF_DUMP_FILTER_MASK \
 416        (((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
 417#define MMF_DUMP_FILTER_DEFAULT \
 418        ((1 << MMF_DUMP_ANON_PRIVATE) | (1 << MMF_DUMP_ANON_SHARED) |\
 419         (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
 420
 421#ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
 422# define MMF_DUMP_MASK_DEFAULT_ELF      (1 << MMF_DUMP_ELF_HEADERS)
 423#else
 424# define MMF_DUMP_MASK_DEFAULT_ELF      0
 425#endif
 426
 427struct sighand_struct {
 428        atomic_t                count;
 429        struct k_sigaction      action[_NSIG];
 430        spinlock_t              siglock;
 431        wait_queue_head_t       signalfd_wqh;
 432};
 433
 434struct pacct_struct {
 435        int                     ac_flag;
 436        long                    ac_exitcode;
 437        unsigned long           ac_mem;
 438        cputime_t               ac_utime, ac_stime;
 439        unsigned long           ac_minflt, ac_majflt;
 440};
 441
 442/**
 443 * struct task_cputime - collected CPU time counts
 444 * @utime:              time spent in user mode, in &cputime_t units
 445 * @stime:              time spent in kernel mode, in &cputime_t units
 446 * @sum_exec_runtime:   total time spent on the CPU, in nanoseconds
 447 *
 448 * This structure groups together three kinds of CPU time that are
 449 * tracked for threads and thread groups.  Most things considering
 450 * CPU time want to group these counts together and treat all three
 451 * of them in parallel.
 452 */
 453struct task_cputime {
 454        cputime_t utime;
 455        cputime_t stime;
 456        unsigned long long sum_exec_runtime;
 457};
 458/* Alternate field names when used to cache expirations. */
 459#define prof_exp        stime
 460#define virt_exp        utime
 461#define sched_exp       sum_exec_runtime
 462
 463#define INIT_CPUTIME    \
 464        (struct task_cputime) {                                 \
 465                .utime = cputime_zero,                          \
 466                .stime = cputime_zero,                          \
 467                .sum_exec_runtime = 0,                          \
 468        }
 469
 470/**
 471 * struct thread_group_cputimer - thread group interval timer counts
 472 * @cputime:            thread group interval timers.
 473 * @running:            non-zero when there are timers running and
 474 *                      @cputime receives updates.
 475 * @lock:               lock for fields in this struct.
 476 *
 477 * This structure contains the version of task_cputime, above, that is
 478 * used for thread group CPU timer calculations.
 479 */
 480struct thread_group_cputimer {
 481        struct task_cputime cputime;
 482        int running;
 483        spinlock_t lock;
 484};
 485
 486/*
 487 * NOTE! "signal_struct" does not have it's own
 488 * locking, because a shared signal_struct always
 489 * implies a shared sighand_struct, so locking
 490 * sighand_struct is always a proper superset of
 491 * the locking of signal_struct.
 492 */
 493struct signal_struct {
 494        atomic_t                count;
 495        atomic_t                live;
 496
 497        wait_queue_head_t       wait_chldexit;  /* for wait4() */
 498
 499        /* current thread group signal load-balancing target: */
 500        struct task_struct      *curr_target;
 501
 502        /* shared signal handling: */
 503        struct sigpending       shared_pending;
 504
 505        /* thread group exit support */
 506        int                     group_exit_code;
 507        /* overloaded:
 508         * - notify group_exit_task when ->count is equal to notify_count
 509         * - everyone except group_exit_task is stopped during signal delivery
 510         *   of fatal signals, group_exit_task processes the signal.
 511         */
 512        int                     notify_count;
 513        struct task_struct      *group_exit_task;
 514
 515        /* thread group stop support, overloads group_exit_code too */
 516        int                     group_stop_count;
 517        unsigned int            flags; /* see SIGNAL_* flags below */
 518
 519        /* POSIX.1b Interval Timers */
 520        struct list_head posix_timers;
 521
 522        /* ITIMER_REAL timer for the process */
 523        struct hrtimer real_timer;
 524        struct pid *leader_pid;
 525        ktime_t it_real_incr;
 526
 527        /* ITIMER_PROF and ITIMER_VIRTUAL timers for the process */
 528        cputime_t it_prof_expires, it_virt_expires;
 529        cputime_t it_prof_incr, it_virt_incr;
 530
 531        /*
 532         * Thread group totals for process CPU timers.
 533         * See thread_group_cputimer(), et al, for details.
 534         */
 535        struct thread_group_cputimer cputimer;
 536
 537        /* Earliest-expiration cache. */
 538        struct task_cputime cputime_expires;
 539
 540        struct list_head cpu_timers[3];
 541
 542        /* job control IDs */
 543
 544        /*
 545         * pgrp and session fields are deprecated.
 546         * use the task_session_Xnr and task_pgrp_Xnr routines below
 547         */
 548
 549        union {
 550                pid_t pgrp __deprecated;
 551                pid_t __pgrp;
 552        };
 553
 554        struct pid *tty_old_pgrp;
 555
 556        union {
 557                pid_t session __deprecated;
 558                pid_t __session;
 559        };
 560
 561        /* boolean value for session group leader */
 562        int leader;
 563
 564        struct tty_struct *tty; /* NULL if no tty */
 565
 566        /*
 567         * Cumulative resource counters for dead threads in the group,
 568         * and for reaped dead child processes forked by this group.
 569         * Live threads maintain their own counters and add to these
 570         * in __exit_signal, except for the group leader.
 571         */
 572        cputime_t utime, stime, cutime, cstime;
 573        cputime_t gtime;
 574        cputime_t cgtime;
 575        unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
 576        unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
 577        unsigned long inblock, oublock, cinblock, coublock;
 578        struct task_io_accounting ioac;
 579
 580        /*
 581         * Cumulative ns of schedule CPU time fo dead threads in the
 582         * group, not including a zombie group leader, (This only differs
 583         * from jiffies_to_ns(utime + stime) if sched_clock uses something
 584         * other than jiffies.)
 585         */
 586        unsigned long long sum_sched_runtime;
 587
 588        /*
 589         * We don't bother to synchronize most readers of this at all,
 590         * because there is no reader checking a limit that actually needs
 591         * to get both rlim_cur and rlim_max atomically, and either one
 592         * alone is a single word that can safely be read normally.
 593         * getrlimit/setrlimit use task_lock(current->group_leader) to
 594         * protect this instead of the siglock, because they really
 595         * have no need to disable irqs.
 596         */
 597        struct rlimit rlim[RLIM_NLIMITS];
 598
 599#ifdef CONFIG_BSD_PROCESS_ACCT
 600        struct pacct_struct pacct;      /* per-process accounting information */
 601#endif
 602#ifdef CONFIG_TASKSTATS
 603        struct taskstats *stats;
 604#endif
 605#ifdef CONFIG_AUDIT
 606        unsigned audit_tty;
 607        struct tty_audit_buf *tty_audit_buf;
 608#endif
 609};
 610
 611/* Context switch must be unlocked if interrupts are to be enabled */
 612#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
 613# define __ARCH_WANT_UNLOCKED_CTXSW
 614#endif
 615
 616/*
 617 * Bits in flags field of signal_struct.
 618 */
 619#define SIGNAL_STOP_STOPPED     0x00000001 /* job control stop in effect */
 620#define SIGNAL_STOP_DEQUEUED    0x00000002 /* stop signal dequeued */
 621#define SIGNAL_STOP_CONTINUED   0x00000004 /* SIGCONT since WCONTINUED reap */
 622#define SIGNAL_GROUP_EXIT       0x00000008 /* group exit in progress */
 623/*
 624 * Pending notifications to parent.
 625 */
 626#define SIGNAL_CLD_STOPPED      0x00000010
 627#define SIGNAL_CLD_CONTINUED    0x00000020
 628#define SIGNAL_CLD_MASK         (SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
 629
 630#define SIGNAL_UNKILLABLE       0x00000040 /* for init: ignore fatal signals */
 631
 632/* If true, all threads except ->group_exit_task have pending SIGKILL */
 633static inline int signal_group_exit(const struct signal_struct *sig)
 634{
 635        return  (sig->flags & SIGNAL_GROUP_EXIT) ||
 636                (sig->group_exit_task != NULL);
 637}
 638
 639/*
 640 * Some day this will be a full-fledged user tracking system..
 641 */
 642struct user_struct {
 643        atomic_t __count;       /* reference count */
 644        atomic_t processes;     /* How many processes does this user have? */
 645        atomic_t files;         /* How many open files does this user have? */
 646        atomic_t sigpending;    /* How many pending signals does this user have? */
 647#ifdef CONFIG_INOTIFY_USER
 648        atomic_t inotify_watches; /* How many inotify watches does this user have? */
 649        atomic_t inotify_devs;  /* How many inotify devs does this user have opened? */
 650#endif
 651#ifdef CONFIG_EPOLL
 652        atomic_t epoll_watches; /* The number of file descriptors currently watched */
 653#endif
 654#ifdef CONFIG_POSIX_MQUEUE
 655        /* protected by mq_lock */
 656        unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */
 657#endif
 658        unsigned long locked_shm; /* How many pages of mlocked shm ? */
 659
 660#ifdef CONFIG_KEYS
 661        struct key *uid_keyring;        /* UID specific keyring */
 662        struct key *session_keyring;    /* UID's default session keyring */
 663#endif
 664
 665        /* Hash table maintenance information */
 666        struct hlist_node uidhash_node;
 667        uid_t uid;
 668        struct user_namespace *user_ns;
 669
 670#ifdef CONFIG_USER_SCHED
 671        struct task_group *tg;
 672#ifdef CONFIG_SYSFS
 673        struct kobject kobj;
 674        struct work_struct work;
 675#endif
 676#endif
 677};
 678
 679extern int uids_sysfs_init(void);
 680
 681extern struct user_struct *find_user(uid_t);
 682
 683extern struct user_struct root_user;
 684#define INIT_USER (&root_user)
 685
 686
 687struct backing_dev_info;
 688struct reclaim_state;
 689
 690#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
 691struct sched_info {
 692        /* cumulative counters */
 693        unsigned long pcount;         /* # of times run on this cpu */
 694        unsigned long long run_delay; /* time spent waiting on a runqueue */
 695
 696        /* timestamps */
 697        unsigned long long last_arrival,/* when we last ran on a cpu */
 698                           last_queued; /* when we were last queued to run */
 699#ifdef CONFIG_SCHEDSTATS
 700        /* BKL stats */
 701        unsigned int bkl_count;
 702#endif
 703};
 704#endif /* defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) */
 705
 706#ifdef CONFIG_TASK_DELAY_ACCT
 707struct task_delay_info {
 708        spinlock_t      lock;
 709        unsigned int    flags;  /* Private per-task flags */
 710
 711        /* For each stat XXX, add following, aligned appropriately
 712         *
 713         * struct timespec XXX_start, XXX_end;
 714         * u64 XXX_delay;
 715         * u32 XXX_count;
 716         *
 717         * Atomicity of updates to XXX_delay, XXX_count protected by
 718         * single lock above (split into XXX_lock if contention is an issue).
 719         */
 720
 721        /*
 722         * XXX_count is incremented on every XXX operation, the delay
 723         * associated with the operation is added to XXX_delay.
 724         * XXX_delay contains the accumulated delay time in nanoseconds.
 725         */
 726        struct timespec blkio_start, blkio_end; /* Shared by blkio, swapin */
 727        u64 blkio_delay;        /* wait for sync block io completion */
 728        u64 swapin_delay;       /* wait for swapin block io completion */
 729        u32 blkio_count;        /* total count of the number of sync block */
 730                                /* io operations performed */
 731        u32 swapin_count;       /* total count of the number of swapin block */
 732                                /* io operations performed */
 733
 734        struct timespec freepages_start, freepages_end;
 735        u64 freepages_delay;    /* wait for memory reclaim */
 736        u32 freepages_count;    /* total count of memory reclaim */
 737};
 738#endif  /* CONFIG_TASK_DELAY_ACCT */
 739
 740static inline int sched_info_on(void)
 741{
 742#ifdef CONFIG_SCHEDSTATS
 743        return 1;
 744#elif defined(CONFIG_TASK_DELAY_ACCT)
 745        extern int delayacct_on;
 746        return delayacct_on;
 747#else
 748        return 0;
 749#endif
 750}
 751
 752enum cpu_idle_type {
 753        CPU_IDLE,
 754        CPU_NOT_IDLE,
 755        CPU_NEWLY_IDLE,
 756        CPU_MAX_IDLE_TYPES
 757};
 758
 759/*
 760 * sched-domains (multiprocessor balancing) declarations:
 761 */
 762
 763/*
 764 * Increase resolution of nice-level calculations:
 765 */
 766#define SCHED_LOAD_SHIFT        10
 767#define SCHED_LOAD_SCALE        (1L << SCHED_LOAD_SHIFT)
 768
 769#define SCHED_LOAD_SCALE_FUZZ   SCHED_LOAD_SCALE
 770
 771#ifdef CONFIG_SMP
 772#define SD_LOAD_BALANCE         1       /* Do load balancing on this domain. */
 773#define SD_BALANCE_NEWIDLE      2       /* Balance when about to become idle */
 774#define SD_BALANCE_EXEC         4       /* Balance on exec */
 775#define SD_BALANCE_FORK         8       /* Balance on fork, clone */
 776#define SD_WAKE_IDLE            16      /* Wake to idle CPU on task wakeup */
 777#define SD_WAKE_AFFINE          32      /* Wake task to waking CPU */
 778#define SD_WAKE_BALANCE         64      /* Perform balancing at task wakeup */
 779#define SD_SHARE_CPUPOWER       128     /* Domain members share cpu power */
 780#define SD_POWERSAVINGS_BALANCE 256     /* Balance for power savings */
 781#define SD_SHARE_PKG_RESOURCES  512     /* Domain members share cpu pkg resources */
 782#define SD_SERIALIZE            1024    /* Only a single load balancing instance */
 783#define SD_WAKE_IDLE_FAR        2048    /* Gain latency sacrificing cache hit */
 784
 785enum powersavings_balance_level {
 786        POWERSAVINGS_BALANCE_NONE = 0,  /* No power saving load balance */
 787        POWERSAVINGS_BALANCE_BASIC,     /* Fill one thread/core/package
 788                                         * first for long running threads
 789                                         */
 790        POWERSAVINGS_BALANCE_WAKEUP,    /* Also bias task wakeups to semi-idle
 791                                         * cpu package for power savings
 792                                         */
 793        MAX_POWERSAVINGS_BALANCE_LEVELS
 794};
 795
 796extern int sched_mc_power_savings, sched_smt_power_savings;
 797
 798static inline int sd_balance_for_mc_power(void)
 799{
 800        if (sched_smt_power_savings)
 801                return SD_POWERSAVINGS_BALANCE;
 802
 803        return 0;
 804}
 805
 806static inline int sd_balance_for_package_power(void)
 807{
 808        if (sched_mc_power_savings | sched_smt_power_savings)
 809                return SD_POWERSAVINGS_BALANCE;
 810
 811        return 0;
 812}
 813
 814/*
 815 * Optimise SD flags for power savings:
 816 * SD_BALANCE_NEWIDLE helps agressive task consolidation and power savings.
 817 * Keep default SD flags if sched_{smt,mc}_power_saving=0
 818 */
 819
 820static inline int sd_power_saving_flags(void)
 821{
 822        if (sched_mc_power_savings | sched_smt_power_savings)
 823                return SD_BALANCE_NEWIDLE;
 824
 825        return 0;
 826}
 827
 828struct sched_group {
 829        struct sched_group *next;       /* Must be a circular list */
 830
 831        /*
 832         * CPU power of this group, SCHED_LOAD_SCALE being max power for a
 833         * single CPU. This is read only (except for setup, hotplug CPU).
 834         * Note : Never change cpu_power without recompute its reciprocal
 835         */
 836        unsigned int __cpu_power;
 837        /*
 838         * reciprocal value of cpu_power to avoid expensive divides
 839         * (see include/linux/reciprocal_div.h)
 840         */
 841        u32 reciprocal_cpu_power;
 842
 843        unsigned long cpumask[];
 844};
 845
 846static inline struct cpumask *sched_group_cpus(struct sched_group *sg)
 847{
 848        return to_cpumask(sg->cpumask);
 849}
 850
 851enum sched_domain_level {
 852        SD_LV_NONE = 0,
 853        SD_LV_SIBLING,
 854        SD_LV_MC,
 855        SD_LV_CPU,
 856        SD_LV_NODE,
 857        SD_LV_ALLNODES,
 858        SD_LV_MAX
 859};
 860
 861struct sched_domain_attr {
 862        int relax_domain_level;
 863};
 864
 865#define SD_ATTR_INIT    (struct sched_domain_attr) {    \
 866        .relax_domain_level = -1,                       \
 867}
 868
 869struct sched_domain {
 870        /* These fields must be setup */
 871        struct sched_domain *parent;    /* top domain must be null terminated */
 872        struct sched_domain *child;     /* bottom domain must be null terminated */
 873        struct sched_group *groups;     /* the balancing groups of the domain */
 874        unsigned long min_interval;     /* Minimum balance interval ms */
 875        unsigned long max_interval;     /* Maximum balance interval ms */
 876        unsigned int busy_factor;       /* less balancing by factor if busy */
 877        unsigned int imbalance_pct;     /* No balance until over watermark */
 878        unsigned int cache_nice_tries;  /* Leave cache hot tasks for # tries */
 879        unsigned int busy_idx;
 880        unsigned int idle_idx;
 881        unsigned int newidle_idx;
 882        unsigned int wake_idx;
 883        unsigned int forkexec_idx;
 884        int flags;                      /* See SD_* */
 885        enum sched_domain_level level;
 886
 887        /* Runtime fields. */
 888        unsigned long last_balance;     /* init to jiffies. units in jiffies */
 889        unsigned int balance_interval;  /* initialise to 1. units in ms. */
 890        unsigned int nr_balance_failed; /* initialise to 0 */
 891
 892        u64 last_update;
 893
 894#ifdef CONFIG_SCHEDSTATS
 895        /* load_balance() stats */
 896        unsigned int lb_count[CPU_MAX_IDLE_TYPES];
 897        unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
 898        unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
 899        unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
 900        unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
 901        unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
 902        unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
 903        unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
 904
 905        /* Active load balancing */
 906        unsigned int alb_count;
 907        unsigned int alb_failed;
 908        unsigned int alb_pushed;
 909
 910        /* SD_BALANCE_EXEC stats */
 911        unsigned int sbe_count;
 912        unsigned int sbe_balanced;
 913        unsigned int sbe_pushed;
 914
 915        /* SD_BALANCE_FORK stats */
 916        unsigned int sbf_count;
 917        unsigned int sbf_balanced;
 918        unsigned int sbf_pushed;
 919
 920        /* try_to_wake_up() stats */
 921        unsigned int ttwu_wake_remote;
 922        unsigned int ttwu_move_affine;
 923        unsigned int ttwu_move_balance;
 924#endif
 925#ifdef CONFIG_SCHED_DEBUG
 926        char *name;
 927#endif
 928
 929        /* span of all CPUs in this domain */
 930        unsigned long span[];
 931};
 932
 933static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
 934{
 935        return to_cpumask(sd->span);
 936}
 937
 938extern void partition_sched_domains(int ndoms_new, struct cpumask *doms_new,
 939                                    struct sched_domain_attr *dattr_new);
 940
 941/* Test a flag in parent sched domain */
 942static inline int test_sd_parent(struct sched_domain *sd, int flag)
 943{
 944        if (sd->parent && (sd->parent->flags & flag))
 945                return 1;
 946
 947        return 0;
 948}
 949
 950#else /* CONFIG_SMP */
 951
 952struct sched_domain_attr;
 953
 954static inline void
 955partition_sched_domains(int ndoms_new, struct cpumask *doms_new,
 956                        struct sched_domain_attr *dattr_new)
 957{
 958}
 959#endif  /* !CONFIG_SMP */
 960
 961struct io_context;                      /* See blkdev.h */
 962
 963
 964#ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
 965extern void prefetch_stack(struct task_struct *t);
 966#else
 967static inline void prefetch_stack(struct task_struct *t) { }
 968#endif
 969
 970struct audit_context;           /* See audit.c */
 971struct mempolicy;
 972struct pipe_inode_info;
 973struct uts_namespace;
 974
 975struct rq;
 976struct sched_domain;
 977
 978struct sched_class {
 979        const struct sched_class *next;
 980
 981        void (*enqueue_task) (struct rq *rq, struct task_struct *p, int wakeup);
 982        void (*dequeue_task) (struct rq *rq, struct task_struct *p, int sleep);
 983        void (*yield_task) (struct rq *rq);
 984
 985        void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int sync);
 986
 987        struct task_struct * (*pick_next_task) (struct rq *rq);
 988        void (*put_prev_task) (struct rq *rq, struct task_struct *p);
 989
 990#ifdef CONFIG_SMP
 991        int  (*select_task_rq)(struct task_struct *p, int sync);
 992
 993        unsigned long (*load_balance) (struct rq *this_rq, int this_cpu,
 994                        struct rq *busiest, unsigned long max_load_move,
 995                        struct sched_domain *sd, enum cpu_idle_type idle,
 996                        int *all_pinned, int *this_best_prio);
 997
 998        int (*move_one_task) (struct rq *this_rq, int this_cpu,
 999                              struct rq *busiest, struct sched_domain *sd,
1000                              enum cpu_idle_type idle);
1001        void (*pre_schedule) (struct rq *this_rq, struct task_struct *task);
1002        void (*post_schedule) (struct rq *this_rq);
1003        void (*task_wake_up) (struct rq *this_rq, struct task_struct *task);
1004
1005        void (*set_cpus_allowed)(struct task_struct *p,
1006                                 const struct cpumask *newmask);
1007
1008        void (*rq_online)(struct rq *rq);
1009        void (*rq_offline)(struct rq *rq);
1010#endif
1011
1012        void (*set_curr_task) (struct rq *rq);
1013        void (*task_tick) (struct rq *rq, struct task_struct *p, int queued);
1014        void (*task_new) (struct rq *rq, struct task_struct *p);
1015
1016        void (*switched_from) (struct rq *this_rq, struct task_struct *task,
1017                               int running);
1018        void (*switched_to) (struct rq *this_rq, struct task_struct *task,
1019                             int running);
1020        void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
1021                             int oldprio, int running);
1022
1023#ifdef CONFIG_FAIR_GROUP_SCHED
1024        void (*moved_group) (struct task_struct *p);
1025#endif
1026};
1027
1028struct load_weight {
1029        unsigned long weight, inv_weight;
1030};
1031
1032/*
1033 * CFS stats for a schedulable entity (task, task-group etc)
1034 *
1035 * Current field usage histogram:
1036 *
1037 *     4 se->block_start
1038 *     4 se->run_node
1039 *     4 se->sleep_start
1040 *     6 se->load.weight
1041 */
1042struct sched_entity {
1043        struct load_weight      load;           /* for load-balancing */
1044        struct rb_node          run_node;
1045        struct list_head        group_node;
1046        unsigned int            on_rq;
1047
1048        u64                     exec_start;
1049        u64                     sum_exec_runtime;
1050        u64                     vruntime;
1051        u64                     prev_sum_exec_runtime;
1052
1053        u64                     last_wakeup;
1054        u64                     avg_overlap;
1055
1056#ifdef CONFIG_SCHEDSTATS
1057        u64                     wait_start;
1058        u64                     wait_max;
1059        u64                     wait_count;
1060        u64                     wait_sum;
1061
1062        u64                     sleep_start;
1063        u64                     sleep_max;
1064        s64                     sum_sleep_runtime;
1065
1066        u64                     block_start;
1067        u64                     block_max;
1068        u64                     exec_max;
1069        u64                     slice_max;
1070
1071        u64                     nr_migrations;
1072        u64                     nr_migrations_cold;
1073        u64                     nr_failed_migrations_affine;
1074        u64                     nr_failed_migrations_running;
1075        u64                     nr_failed_migrations_hot;
1076        u64                     nr_forced_migrations;
1077        u64                     nr_forced2_migrations;
1078
1079        u64                     nr_wakeups;
1080        u64                     nr_wakeups_sync;
1081        u64                     nr_wakeups_migrate;
1082        u64                     nr_wakeups_local;
1083        u64                     nr_wakeups_remote;
1084        u64                     nr_wakeups_affine;
1085        u64                     nr_wakeups_affine_attempts;
1086        u64                     nr_wakeups_passive;
1087        u64                     nr_wakeups_idle;
1088#endif
1089
1090#ifdef CONFIG_FAIR_GROUP_SCHED
1091        struct sched_entity     *parent;
1092        /* rq on which this entity is (to be) queued: */
1093        struct cfs_rq           *cfs_rq;
1094        /* rq "owned" by this entity/group: */
1095        struct cfs_rq           *my_q;
1096#endif
1097};
1098
1099struct sched_rt_entity {
1100        struct list_head run_list;
1101        unsigned long timeout;
1102        unsigned int time_slice;
1103        int nr_cpus_allowed;
1104
1105        struct sched_rt_entity *back;
1106#ifdef CONFIG_RT_GROUP_SCHED
1107        struct sched_rt_entity  *parent;
1108        /* rq on which this entity is (to be) queued: */
1109        struct rt_rq            *rt_rq;
1110        /* rq "owned" by this entity/group: */
1111        struct rt_rq            *my_q;
1112#endif
1113};
1114
1115struct task_struct {
1116        volatile long state;    /* -1 unrunnable, 0 runnable, >0 stopped */
1117        void *stack;
1118        atomic_t usage;
1119        unsigned int flags;     /* per process flags, defined below */
1120        unsigned int ptrace;
1121
1122        int lock_depth;         /* BKL lock depth */
1123
1124#ifdef CONFIG_SMP
1125#ifdef __ARCH_WANT_UNLOCKED_CTXSW
1126        int oncpu;
1127#endif
1128#endif
1129
1130        int prio, static_prio, normal_prio;
1131        unsigned int rt_priority;
1132        const struct sched_class *sched_class;
1133        struct sched_entity se;
1134        struct sched_rt_entity rt;
1135
1136#ifdef CONFIG_PREEMPT_NOTIFIERS
1137        /* list of struct preempt_notifier: */
1138        struct hlist_head preempt_notifiers;
1139#endif
1140
1141        /*
1142         * fpu_counter contains the number of consecutive context switches
1143         * that the FPU is used. If this is over a threshold, the lazy fpu
1144         * saving becomes unlazy to save the trap. This is an unsigned char
1145         * so that after 256 times the counter wraps and the behavior turns
1146         * lazy again; this to deal with bursty apps that only use FPU for
1147         * a short time
1148         */
1149        unsigned char fpu_counter;
1150        s8 oomkilladj; /* OOM kill score adjustment (bit shift). */
1151#ifdef CONFIG_BLK_DEV_IO_TRACE
1152        unsigned int btrace_seq;
1153#endif
1154
1155        unsigned int policy;
1156        cpumask_t cpus_allowed;
1157
1158#ifdef CONFIG_PREEMPT_RCU
1159        int rcu_read_lock_nesting;
1160        int rcu_flipctr_idx;
1161#endif /* #ifdef CONFIG_PREEMPT_RCU */
1162
1163#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
1164        struct sched_info sched_info;
1165#endif
1166
1167        struct list_head tasks;
1168
1169        struct mm_struct *mm, *active_mm;
1170
1171/* task state */
1172        struct linux_binfmt *binfmt;
1173        int exit_state;
1174        int exit_code, exit_signal;
1175        int pdeath_signal;  /*  The signal sent when the parent dies  */
1176        /* ??? */
1177        unsigned int personality;
1178        unsigned did_exec:1;
1179        pid_t pid;
1180        pid_t tgid;
1181
1182#ifdef CONFIG_CC_STACKPROTECTOR
1183        /* Canary value for the -fstack-protector gcc feature */
1184        unsigned long stack_canary;
1185#endif
1186        /* 
1187         * pointers to (original) parent process, youngest child, younger sibling,
1188         * older sibling, respectively.  (p->father can be replaced with 
1189         * p->real_parent->pid)
1190         */
1191        struct task_struct *real_parent; /* real parent process */
1192        struct task_struct *parent; /* recipient of SIGCHLD, wait4() reports */
1193        /*
1194         * children/sibling forms the list of my natural children
1195         */
1196        struct list_head children;      /* list of my children */
1197        struct list_head sibling;       /* linkage in my parent's children list */
1198        struct task_struct *group_leader;       /* threadgroup leader */
1199
1200        /*
1201         * ptraced is the list of tasks this task is using ptrace on.
1202         * This includes both natural children and PTRACE_ATTACH targets.
1203         * p->ptrace_entry is p's link on the p->parent->ptraced list.
1204         */
1205        struct list_head ptraced;
1206        struct list_head ptrace_entry;
1207
1208#ifdef CONFIG_X86_PTRACE_BTS
1209        /*
1210         * This is the tracer handle for the ptrace BTS extension.
1211         * This field actually belongs to the ptracer task.
1212         */
1213        struct bts_tracer *bts;
1214        /*
1215         * The buffer to hold the BTS data.
1216         */
1217        void *bts_buffer;
1218        size_t bts_size;
1219#endif /* CONFIG_X86_PTRACE_BTS */
1220
1221        /* PID/PID hash table linkage. */
1222        struct pid_link pids[PIDTYPE_MAX];
1223        struct list_head thread_group;
1224
1225        struct completion *vfork_done;          /* for vfork() */
1226        int __user *set_child_tid;              /* CLONE_CHILD_SETTID */
1227        int __user *clear_child_tid;            /* CLONE_CHILD_CLEARTID */
1228
1229        cputime_t utime, stime, utimescaled, stimescaled;
1230        cputime_t gtime;
1231        cputime_t prev_utime, prev_stime;
1232        unsigned long nvcsw, nivcsw; /* context switch counts */
1233        struct timespec start_time;             /* monotonic time */
1234        struct timespec real_start_time;        /* boot based time */
1235/* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1236        unsigned long min_flt, maj_flt;
1237
1238        struct task_cputime cputime_expires;
1239        struct list_head cpu_timers[3];
1240
1241/* process credentials */
1242        const struct cred *real_cred;   /* objective and real subjective task
1243                                         * credentials (COW) */
1244        const struct cred *cred;        /* effective (overridable) subjective task
1245                                         * credentials (COW) */
1246        struct mutex cred_exec_mutex;   /* execve vs ptrace cred calculation mutex */
1247
1248        char comm[TASK_COMM_LEN]; /* executable name excluding path
1249                                     - access with [gs]et_task_comm (which lock
1250                                       it with task_lock())
1251                                     - initialized normally by flush_old_exec */
1252/* file system info */
1253        int link_count, total_link_count;
1254#ifdef CONFIG_SYSVIPC
1255/* ipc stuff */
1256        struct sysv_sem sysvsem;
1257#endif
1258#ifdef CONFIG_DETECT_SOFTLOCKUP
1259/* hung task detection */
1260        unsigned long last_switch_timestamp;
1261        unsigned long last_switch_count;
1262#endif
1263/* CPU-specific state of this task */
1264        struct thread_struct thread;
1265/* filesystem information */
1266        struct fs_struct *fs;
1267/* open file information */
1268        struct files_struct *files;
1269/* namespaces */
1270        struct nsproxy *nsproxy;
1271/* signal handlers */
1272        struct signal_struct *signal;
1273        struct sighand_struct *sighand;
1274
1275        sigset_t blocked, real_blocked;
1276        sigset_t saved_sigmask; /* restored if set_restore_sigmask() was used */
1277        struct sigpending pending;
1278
1279        unsigned long sas_ss_sp;
1280        size_t sas_ss_size;
1281        int (*notifier)(void *priv);
1282        void *notifier_data;
1283        sigset_t *notifier_mask;
1284        struct audit_context *audit_context;
1285#ifdef CONFIG_AUDITSYSCALL
1286        uid_t loginuid;
1287        unsigned int sessionid;
1288#endif
1289        seccomp_t seccomp;
1290
1291/* Thread group tracking */
1292        u32 parent_exec_id;
1293        u32 self_exec_id;
1294/* Protection of (de-)allocation: mm, files, fs, tty, keyrings */
1295        spinlock_t alloc_lock;
1296
1297        /* Protection of the PI data structures: */
1298        spinlock_t pi_lock;
1299
1300#ifdef CONFIG_RT_MUTEXES
1301        /* PI waiters blocked on a rt_mutex held by this task */
1302        struct plist_head pi_waiters;
1303        /* Deadlock detection and priority inheritance handling */
1304        struct rt_mutex_waiter *pi_blocked_on;
1305#endif
1306
1307#ifdef CONFIG_DEBUG_MUTEXES
1308        /* mutex deadlock detection */
1309        struct mutex_waiter *blocked_on;
1310#endif
1311#ifdef CONFIG_TRACE_IRQFLAGS
1312        unsigned int irq_events;
1313        int hardirqs_enabled;
1314        unsigned long hardirq_enable_ip;
1315        unsigned int hardirq_enable_event;
1316        unsigned long hardirq_disable_ip;
1317        unsigned int hardirq_disable_event;
1318        int softirqs_enabled;
1319        unsigned long softirq_disable_ip;
1320        unsigned int softirq_disable_event;
1321        unsigned long softirq_enable_ip;
1322        unsigned int softirq_enable_event;
1323        int hardirq_context;
1324        int softirq_context;
1325#endif
1326#ifdef CONFIG_LOCKDEP
1327# define MAX_LOCK_DEPTH 48UL
1328        u64 curr_chain_key;
1329        int lockdep_depth;
1330        unsigned int lockdep_recursion;
1331        struct held_lock held_locks[MAX_LOCK_DEPTH];
1332#endif
1333
1334/* journalling filesystem info */
1335        void *journal_info;
1336
1337/* stacked block device info */
1338        struct bio *bio_list, **bio_tail;
1339
1340/* VM state */
1341        struct reclaim_state *reclaim_state;
1342
1343        struct backing_dev_info *backing_dev_info;
1344
1345        struct io_context *io_context;
1346
1347        unsigned long ptrace_message;
1348        siginfo_t *last_siginfo; /* For ptrace use.  */
1349        struct task_io_accounting ioac;
1350#if defined(CONFIG_TASK_XACCT)
1351        u64 acct_rss_mem1;      /* accumulated rss usage */
1352        u64 acct_vm_mem1;       /* accumulated virtual memory usage */
1353        cputime_t acct_timexpd; /* stime + utime since last update */
1354#endif
1355#ifdef CONFIG_CPUSETS
1356        nodemask_t mems_allowed;
1357        int cpuset_mems_generation;
1358        int cpuset_mem_spread_rotor;
1359#endif
1360#ifdef CONFIG_CGROUPS
1361        /* Control Group info protected by css_set_lock */
1362        struct css_set *cgroups;
1363        /* cg_list protected by css_set_lock and tsk->alloc_lock */
1364        struct list_head cg_list;
1365#endif
1366#ifdef CONFIG_FUTEX
1367        struct robust_list_head __user *robust_list;
1368#ifdef CONFIG_COMPAT
1369        struct compat_robust_list_head __user *compat_robust_list;
1370#endif
1371        struct list_head pi_state_list;
1372        struct futex_pi_state *pi_state_cache;
1373#endif
1374#ifdef CONFIG_NUMA
1375        struct mempolicy *mempolicy;
1376        short il_next;
1377#endif
1378        atomic_t fs_excl;       /* holding fs exclusive resources */
1379        struct rcu_head rcu;
1380
1381        /*
1382         * cache last used pipe for splice
1383         */
1384        struct pipe_inode_info *splice_pipe;
1385#ifdef  CONFIG_TASK_DELAY_ACCT
1386        struct task_delay_info *delays;
1387#endif
1388#ifdef CONFIG_FAULT_INJECTION
1389        int make_it_fail;
1390#endif
1391        struct prop_local_single dirties;
1392#ifdef CONFIG_LATENCYTOP
1393        int latency_record_count;
1394        struct latency_record latency_record[LT_SAVECOUNT];
1395#endif
1396        /*
1397         * time slack values; these are used to round up poll() and
1398         * select() etc timeout values. These are in nanoseconds.
1399         */
1400        unsigned long timer_slack_ns;
1401        unsigned long default_timer_slack_ns;
1402
1403        struct list_head        *scm_work_list;
1404#ifdef CONFIG_FUNCTION_GRAPH_TRACER
1405        /* Index of current stored adress in ret_stack */
1406        int curr_ret_stack;
1407        /* Stack of return addresses for return function tracing */
1408        struct ftrace_ret_stack *ret_stack;
1409        /*
1410         * Number of functions that haven't been traced
1411         * because of depth overrun.
1412         */
1413        atomic_t trace_overrun;
1414        /* Pause for the tracing */
1415        atomic_t tracing_graph_pause;
1416#endif
1417#ifdef CONFIG_TRACING
1418        /* state flags for use by tracers */
1419        unsigned long trace;
1420#endif
1421};
1422
1423/* Future-safe accessor for struct task_struct's cpus_allowed. */
1424#define tsk_cpumask(tsk) (&(tsk)->cpus_allowed)
1425
1426/*
1427 * Priority of a process goes from 0..MAX_PRIO-1, valid RT
1428 * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
1429 * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority
1430 * values are inverted: lower p->prio value means higher priority.
1431 *
1432 * The MAX_USER_RT_PRIO value allows the actual maximum
1433 * RT priority to be separate from the value exported to
1434 * user-space.  This allows kernel threads to set their
1435 * priority to a value higher than any user task. Note:
1436 * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
1437 */
1438
1439#define MAX_USER_RT_PRIO        100
1440#define MAX_RT_PRIO             MAX_USER_RT_PRIO
1441
1442#define MAX_PRIO                (MAX_RT_PRIO + 40)
1443#define DEFAULT_PRIO            (MAX_RT_PRIO + 20)
1444
1445static inline int rt_prio(int prio)
1446{
1447        if (unlikely(prio < MAX_RT_PRIO))
1448                return 1;
1449        return 0;
1450}
1451
1452static inline int rt_task(struct task_struct *p)
1453{
1454        return rt_prio(p->prio);
1455}
1456
1457static inline void set_task_session(struct task_struct *tsk, pid_t session)
1458{
1459        tsk->signal->__session = session;
1460}
1461
1462static inline void set_task_pgrp(struct task_struct *tsk, pid_t pgrp)
1463{
1464        tsk->signal->__pgrp = pgrp;
1465}
1466
1467static inline struct pid *task_pid(struct task_struct *task)
1468{
1469        return task->pids[PIDTYPE_PID].pid;
1470}
1471
1472static inline struct pid *task_tgid(struct task_struct *task)
1473{
1474        return task->group_leader->pids[PIDTYPE_PID].pid;
1475}
1476
1477static inline struct pid *task_pgrp(struct task_struct *task)
1478{
1479        return task->group_leader->pids[PIDTYPE_PGID].pid;
1480}
1481
1482static inline struct pid *task_session(struct task_struct *task)
1483{
1484        return task->group_leader->pids[PIDTYPE_SID].pid;
1485}
1486
1487struct pid_namespace;
1488
1489/*
1490 * the helpers to get the task's different pids as they are seen
1491 * from various namespaces
1492 *
1493 * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1494 * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1495 *                     current.
1496 * task_xid_nr_ns()  : id seen from the ns specified;
1497 *
1498 * set_task_vxid()   : assigns a virtual id to a task;
1499 *
1500 * see also pid_nr() etc in include/linux/pid.h
1501 */
1502
1503static inline pid_t task_pid_nr(struct task_struct *tsk)
1504{
1505        return tsk->pid;
1506}
1507
1508pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1509
1510static inline pid_t task_pid_vnr(struct task_struct *tsk)
1511{
1512        return pid_vnr(task_pid(tsk));
1513}
1514
1515
1516static inline pid_t task_tgid_nr(struct task_struct *tsk)
1517{
1518        return tsk->tgid;
1519}
1520
1521pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1522
1523static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1524{
1525        return pid_vnr(task_tgid(tsk));
1526}
1527
1528
1529static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1530{
1531        return tsk->signal->__pgrp;
1532}
1533
1534pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1535
1536static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1537{
1538        return pid_vnr(task_pgrp(tsk));
1539}
1540
1541
1542static inline pid_t task_session_nr(struct task_struct *tsk)
1543{
1544        return tsk->signal->__session;
1545}
1546
1547pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1548
1549static inline pid_t task_session_vnr(struct task_struct *tsk)
1550{
1551        return pid_vnr(task_session(tsk));
1552}
1553
1554
1555/**
1556 * pid_alive - check that a task structure is not stale
1557 * @p: Task structure to be checked.
1558 *
1559 * Test if a process is not yet dead (at most zombie state)
1560 * If pid_alive fails, then pointers within the task structure
1561 * can be stale and must not be dereferenced.
1562 */
1563static inline int pid_alive(struct task_struct *p)
1564{
1565        return p->pids[PIDTYPE_PID].pid != NULL;
1566}
1567
1568/**
1569 * is_global_init - check if a task structure is init
1570 * @tsk: Task structure to be checked.
1571 *
1572 * Check if a task structure is the first user space task the kernel created.
1573 */
1574static inline int is_global_init(struct task_struct *tsk)
1575{
1576        return tsk->pid == 1;
1577}
1578
1579/*
1580 * is_container_init:
1581 * check whether in the task is init in its own pid namespace.
1582 */
1583extern int is_container_init(struct task_struct *tsk);
1584
1585extern struct pid *cad_pid;
1586
1587extern void free_task(struct task_struct *tsk);
1588#define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
1589
1590extern void __put_task_struct(struct task_struct *t);
1591
1592static inline void put_task_struct(struct task_struct *t)
1593{
1594        if (atomic_dec_and_test(&t->usage))
1595                __put_task_struct(t);
1596}
1597
1598extern cputime_t task_utime(struct task_struct *p);
1599extern cputime_t task_stime(struct task_struct *p);
1600extern cputime_t task_gtime(struct task_struct *p);
1601
1602/*
1603 * Per process flags
1604 */
1605#define PF_ALIGNWARN    0x00000001      /* Print alignment warning msgs */
1606                                        /* Not implemented yet, only for 486*/
1607#define PF_STARTING     0x00000002      /* being created */
1608#define PF_EXITING      0x00000004      /* getting shut down */
1609#define PF_EXITPIDONE   0x00000008      /* pi exit done on shut down */
1610#define PF_VCPU         0x00000010      /* I'm a virtual CPU */
1611#define PF_FORKNOEXEC   0x00000040      /* forked but didn't exec */
1612#define PF_SUPERPRIV    0x00000100      /* used super-user privileges */
1613#define PF_DUMPCORE     0x00000200      /* dumped core */
1614#define PF_SIGNALED     0x00000400      /* killed by a signal */
1615#define PF_MEMALLOC     0x00000800      /* Allocating memory */
1616#define PF_FLUSHER      0x00001000      /* responsible for disk writeback */
1617#define PF_USED_MATH    0x00002000      /* if unset the fpu must be initialized before use */
1618#define PF_NOFREEZE     0x00008000      /* this thread should not be frozen */
1619#define PF_FROZEN       0x00010000      /* frozen for system suspend */
1620#define PF_FSTRANS      0x00020000      /* inside a filesystem transaction */
1621#define PF_KSWAPD       0x00040000      /* I am kswapd */
1622#define PF_SWAPOFF      0x00080000      /* I am in swapoff */
1623#define PF_LESS_THROTTLE 0x00100000     /* Throttle me less: I clean memory */
1624#define PF_KTHREAD      0x00200000      /* I am a kernel thread */
1625#define PF_RANDOMIZE    0x00400000      /* randomize virtual address space */
1626#define PF_SWAPWRITE    0x00800000      /* Allowed to write to swap */
1627#define PF_SPREAD_PAGE  0x01000000      /* Spread page cache over cpuset */
1628#define PF_SPREAD_SLAB  0x02000000      /* Spread some slab caches over cpuset */
1629#define PF_THREAD_BOUND 0x04000000      /* Thread bound to specific cpu */
1630#define PF_MEMPOLICY    0x10000000      /* Non-default NUMA mempolicy */
1631#define PF_MUTEX_TESTER 0x20000000      /* Thread belongs to the rt mutex tester */
1632#define PF_FREEZER_SKIP 0x40000000      /* Freezer should not count it as freezeable */
1633#define PF_FREEZER_NOSIG 0x80000000     /* Freezer won't send signals to it */
1634
1635/*
1636 * Only the _current_ task can read/write to tsk->flags, but other
1637 * tasks can access tsk->flags in readonly mode for example
1638 * with tsk_used_math (like during threaded core dumping).
1639 * There is however an exception to this rule during ptrace
1640 * or during fork: the ptracer task is allowed to write to the
1641 * child->flags of its traced child (same goes for fork, the parent
1642 * can write to the child->flags), because we're guaranteed the
1643 * child is not running and in turn not changing child->flags
1644 * at the same time the parent does it.
1645 */
1646#define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1647#define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1648#define clear_used_math() clear_stopped_child_used_math(current)
1649#define set_used_math() set_stopped_child_used_math(current)
1650#define conditional_stopped_child_used_math(condition, child) \
1651        do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1652#define conditional_used_math(condition) \
1653        conditional_stopped_child_used_math(condition, current)
1654#define copy_to_stopped_child_used_math(child) \
1655        do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1656/* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1657#define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1658#define used_math() tsk_used_math(current)
1659
1660#ifdef CONFIG_SMP
1661extern int set_cpus_allowed_ptr(struct task_struct *p,
1662                                const struct cpumask *new_mask);
1663#else
1664static inline int set_cpus_allowed_ptr(struct task_struct *p,
1665                                       const struct cpumask *new_mask)
1666{
1667        if (!cpumask_test_cpu(0, new_mask))
1668                return -EINVAL;
1669        return 0;
1670}
1671#endif
1672static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
1673{
1674        return set_cpus_allowed_ptr(p, &new_mask);
1675}
1676
1677extern unsigned long long sched_clock(void);
1678
1679extern void sched_clock_init(void);
1680extern u64 sched_clock_cpu(int cpu);
1681
1682#ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
1683static inline void sched_clock_tick(void)
1684{
1685}
1686
1687static inline void sched_clock_idle_sleep_event(void)
1688{
1689}
1690
1691static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
1692{
1693}
1694#else
1695extern void sched_clock_tick(void);
1696extern void sched_clock_idle_sleep_event(void);
1697extern void sched_clock_idle_wakeup_event(u64 delta_ns);
1698#endif
1699
1700/*
1701 * For kernel-internal use: high-speed (but slightly incorrect) per-cpu
1702 * clock constructed from sched_clock():
1703 */
1704extern unsigned long long cpu_clock(int cpu);
1705
1706extern unsigned long long
1707task_sched_runtime(struct task_struct *task);
1708extern unsigned long long thread_group_sched_runtime(struct task_struct *task);
1709
1710/* sched_exec is called by processes performing an exec */
1711#ifdef CONFIG_SMP
1712extern void sched_exec(void);
1713#else
1714#define sched_exec()   {}
1715#endif
1716
1717extern void sched_clock_idle_sleep_event(void);
1718extern void sched_clock_idle_wakeup_event(u64 delta_ns);
1719
1720#ifdef CONFIG_HOTPLUG_CPU
1721extern void idle_task_exit(void);
1722#else
1723static inline void idle_task_exit(void) {}
1724#endif
1725
1726extern void sched_idle_next(void);
1727
1728#if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP)
1729extern void wake_up_idle_cpu(int cpu);
1730#else
1731static inline void wake_up_idle_cpu(int cpu) { }
1732#endif
1733
1734extern unsigned int sysctl_sched_latency;
1735extern unsigned int sysctl_sched_min_granularity;
1736extern unsigned int sysctl_sched_wakeup_granularity;
1737extern unsigned int sysctl_sched_shares_ratelimit;
1738extern unsigned int sysctl_sched_shares_thresh;
1739#ifdef CONFIG_SCHED_DEBUG
1740extern unsigned int sysctl_sched_child_runs_first;
1741extern unsigned int sysctl_sched_features;
1742extern unsigned int sysctl_sched_migration_cost;
1743extern unsigned int sysctl_sched_nr_migrate;
1744
1745int sched_nr_latency_handler(struct ctl_table *table, int write,
1746                struct file *file, void __user *buffer, size_t *length,
1747                loff_t *ppos);
1748#endif
1749extern unsigned int sysctl_sched_rt_period;
1750extern int sysctl_sched_rt_runtime;
1751
1752int sched_rt_handler(struct ctl_table *table, int write,
1753                struct file *filp, void __user *buffer, size_t *lenp,
1754                loff_t *ppos);
1755
1756extern unsigned int sysctl_sched_compat_yield;
1757
1758#ifdef CONFIG_RT_MUTEXES
1759extern int rt_mutex_getprio(struct task_struct *p);
1760extern void rt_mutex_setprio(struct task_struct *p, int prio);
1761extern void rt_mutex_adjust_pi(struct task_struct *p);
1762#else
1763static inline int rt_mutex_getprio(struct task_struct *p)
1764{
1765        return p->normal_prio;
1766}
1767# define rt_mutex_adjust_pi(p)          do { } while (0)
1768#endif
1769
1770extern void set_user_nice(struct task_struct *p, long nice);
1771extern int task_prio(const struct task_struct *p);
1772extern int task_nice(const struct task_struct *p);
1773extern int can_nice(const struct task_struct *p, const int nice);
1774extern int task_curr(const struct task_struct *p);
1775extern int idle_cpu(int cpu);
1776extern int sched_setscheduler(struct task_struct *, int, struct sched_param *);
1777extern int sched_setscheduler_nocheck(struct task_struct *, int,
1778                                      struct sched_param *);
1779extern struct task_struct *idle_task(int cpu);
1780extern struct task_struct *curr_task(int cpu);
1781extern void set_curr_task(int cpu, struct task_struct *p);
1782
1783void yield(void);
1784
1785/*
1786 * The default (Linux) execution domain.
1787 */
1788extern struct exec_domain       default_exec_domain;
1789
1790union thread_union {
1791        struct thread_info thread_info;
1792        unsigned long stack[THREAD_SIZE/sizeof(long)];
1793};
1794
1795#ifndef __HAVE_ARCH_KSTACK_END
1796static inline int kstack_end(void *addr)
1797{
1798        /* Reliable end of stack detection:
1799         * Some APM bios versions misalign the stack
1800         */
1801        return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
1802}
1803#endif
1804
1805extern union thread_union init_thread_union;
1806extern struct task_struct init_task;
1807
1808extern struct   mm_struct init_mm;
1809
1810extern struct pid_namespace init_pid_ns;
1811
1812/*
1813 * find a task by one of its numerical ids
1814 *
1815 * find_task_by_pid_type_ns():
1816 *      it is the most generic call - it finds a task by all id,
1817 *      type and namespace specified
1818 * find_task_by_pid_ns():
1819 *      finds a task by its pid in the specified namespace
1820 * find_task_by_vpid():
1821 *      finds a task by its virtual pid
1822 *
1823 * see also find_vpid() etc in include/linux/pid.h
1824 */
1825
1826extern struct task_struct *find_task_by_pid_type_ns(int type, int pid,
1827                struct pid_namespace *ns);
1828
1829extern struct task_struct *find_task_by_vpid(pid_t nr);
1830extern struct task_struct *find_task_by_pid_ns(pid_t nr,
1831                struct pid_namespace *ns);
1832
1833extern void __set_special_pids(struct pid *pid);
1834
1835/* per-UID process charging. */
1836extern struct user_struct * alloc_uid(struct user_namespace *, uid_t);
1837static inline struct user_struct *get_uid(struct user_struct *u)
1838{
1839        atomic_inc(&u->__count);
1840        return u;
1841}
1842extern void free_uid(struct user_struct *);
1843extern void release_uids(struct user_namespace *ns);
1844
1845#include <asm/current.h>
1846
1847extern void do_timer(unsigned long ticks);
1848
1849extern int wake_up_state(struct task_struct *tsk, unsigned int state);
1850extern int wake_up_process(struct task_struct *tsk);
1851extern void wake_up_new_task(struct task_struct *tsk,
1852                                unsigned long clone_flags);
1853#ifdef CONFIG_SMP
1854 extern void kick_process(struct task_struct *tsk);
1855#else
1856 static inline void kick_process(struct task_struct *tsk) { }
1857#endif
1858extern void sched_fork(struct task_struct *p, int clone_flags);
1859extern void sched_dead(struct task_struct *p);
1860
1861extern void proc_caches_init(void);
1862extern void flush_signals(struct task_struct *);
1863extern void ignore_signals(struct task_struct *);
1864extern void flush_signal_handlers(struct task_struct *, int force_default);
1865extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
1866
1867static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
1868{
1869        unsigned long flags;
1870        int ret;
1871
1872        spin_lock_irqsave(&tsk->sighand->siglock, flags);
1873        ret = dequeue_signal(tsk, mask, info);
1874        spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
1875
1876        return ret;
1877}       
1878
1879extern void block_all_signals(int (*notifier)(void *priv), void *priv,
1880                              sigset_t *mask);
1881extern void unblock_all_signals(void);
1882extern void release_task(struct task_struct * p);
1883extern int send_sig_info(int, struct siginfo *, struct task_struct *);
1884extern int force_sigsegv(int, struct task_struct *);
1885extern int force_sig_info(int, struct siginfo *, struct task_struct *);
1886extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
1887extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
1888extern int kill_pid_info_as_uid(int, struct siginfo *, struct pid *, uid_t, uid_t, u32);
1889extern int kill_pgrp(struct pid *pid, int sig, int priv);
1890extern int kill_pid(struct pid *pid, int sig, int priv);
1891extern int kill_proc_info(int, struct siginfo *, pid_t);
1892extern int do_notify_parent(struct task_struct *, int);
1893extern void force_sig(int, struct task_struct *);
1894extern void force_sig_specific(int, struct task_struct *);
1895extern int send_sig(int, struct task_struct *, int);
1896extern void zap_other_threads(struct task_struct *p);
1897extern struct sigqueue *sigqueue_alloc(void);
1898extern void sigqueue_free(struct sigqueue *);
1899extern int send_sigqueue(struct sigqueue *,  struct task_struct *, int group);
1900extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
1901extern int do_sigaltstack(const stack_t __user *, stack_t __user *, unsigned long);
1902
1903static inline int kill_cad_pid(int sig, int priv)
1904{
1905        return kill_pid(cad_pid, sig, priv);
1906}
1907
1908/* These can be the second arg to send_sig_info/send_group_sig_info.  */
1909#define SEND_SIG_NOINFO ((struct siginfo *) 0)
1910#define SEND_SIG_PRIV   ((struct siginfo *) 1)
1911#define SEND_SIG_FORCED ((struct siginfo *) 2)
1912
1913static inline int is_si_special(const struct siginfo *info)
1914{
1915        return info <= SEND_SIG_FORCED;
1916}
1917
1918/* True if we are on the alternate signal stack.  */
1919
1920static inline int on_sig_stack(unsigned long sp)
1921{
1922        return (sp - current->sas_ss_sp < current->sas_ss_size);
1923}
1924
1925static inline int sas_ss_flags(unsigned long sp)
1926{
1927        return (current->sas_ss_size == 0 ? SS_DISABLE
1928                : on_sig_stack(sp) ? SS_ONSTACK : 0);
1929}
1930
1931/*
1932 * Routines for handling mm_structs
1933 */
1934extern struct mm_struct * mm_alloc(void);
1935
1936/* mmdrop drops the mm and the page tables */
1937extern void __mmdrop(struct mm_struct *);
1938static inline void mmdrop(struct mm_struct * mm)
1939{
1940        if (unlikely(atomic_dec_and_test(&mm->mm_count)))
1941                __mmdrop(mm);
1942}
1943
1944/* mmput gets rid of the mappings and all user-space */
1945extern void mmput(struct mm_struct *);
1946/* Grab a reference to a task's mm, if it is not already going away */
1947extern struct mm_struct *get_task_mm(struct task_struct *task);
1948/* Remove the current tasks stale references to the old mm_struct */
1949extern void mm_release(struct task_struct *, struct mm_struct *);
1950/* Allocate a new mm structure and copy contents from tsk->mm */
1951extern struct mm_struct *dup_mm(struct task_struct *tsk);
1952
1953extern int  copy_thread(int, unsigned long, unsigned long, unsigned long, struct task_struct *, struct pt_regs *);
1954extern void flush_thread(void);
1955extern void exit_thread(void);
1956
1957extern void exit_files(struct task_struct *);
1958extern void __cleanup_signal(struct signal_struct *);
1959extern void __cleanup_sighand(struct sighand_struct *);
1960
1961extern void exit_itimers(struct signal_struct *);
1962extern void flush_itimer_signals(void);
1963
1964extern NORET_TYPE void do_group_exit(int);
1965
1966extern void daemonize(const char *, ...);
1967extern int allow_signal(int);
1968extern int disallow_signal(int);
1969
1970extern int do_execve(char *, char __user * __user *, char __user * __user *, struct pt_regs *);
1971extern long do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *);
1972struct task_struct *fork_idle(int);
1973
1974extern void set_task_comm(struct task_struct *tsk, char *from);
1975extern char *get_task_comm(char *to, struct task_struct *tsk);
1976
1977#ifdef CONFIG_SMP
1978extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
1979#else
1980static inline unsigned long wait_task_inactive(struct task_struct *p,
1981                                               long match_state)
1982{
1983        return 1;
1984}
1985#endif
1986
1987#define next_task(p)    list_entry(rcu_dereference((p)->tasks.next), struct task_struct, tasks)
1988
1989#define for_each_process(p) \
1990        for (p = &init_task ; (p = next_task(p)) != &init_task ; )
1991
1992extern bool is_single_threaded(struct task_struct *);
1993
1994/*
1995 * Careful: do_each_thread/while_each_thread is a double loop so
1996 *          'break' will not work as expected - use goto instead.
1997 */
1998#define do_each_thread(g, t) \
1999        for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
2000
2001#define while_each_thread(g, t) \
2002        while ((t = next_thread(t)) != g)
2003
2004/* de_thread depends on thread_group_leader not being a pid based check */
2005#define thread_group_leader(p)  (p == p->group_leader)
2006
2007/* Do to the insanities of de_thread it is possible for a process
2008 * to have the pid of the thread group leader without actually being
2009 * the thread group leader.  For iteration through the pids in proc
2010 * all we care about is that we have a task with the appropriate
2011 * pid, we don't actually care if we have the right task.
2012 */
2013static inline int has_group_leader_pid(struct task_struct *p)
2014{
2015        return p->pid == p->tgid;
2016}
2017
2018static inline
2019int same_thread_group(struct task_struct *p1, struct task_struct *p2)
2020{
2021        return p1->tgid == p2->tgid;
2022}
2023
2024static inline struct task_struct *next_thread(const struct task_struct *p)
2025{
2026        return list_entry(rcu_dereference(p->thread_group.next),
2027                          struct task_struct, thread_group);
2028}
2029
2030static inline int thread_group_empty(struct task_struct *p)
2031{
2032        return list_empty(&p->thread_group);
2033}
2034
2035#define delay_group_leader(p) \
2036                (thread_group_leader(p) && !thread_group_empty(p))
2037
2038/*
2039 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
2040 * subscriptions and synchronises with wait4().  Also used in procfs.  Also
2041 * pins the final release of task.io_context.  Also protects ->cpuset and
2042 * ->cgroup.subsys[].
2043 *
2044 * Nests both inside and outside of read_lock(&tasklist_lock).
2045 * It must not be nested with write_lock_irq(&tasklist_lock),
2046 * neither inside nor outside.
2047 */
2048static inline void task_lock(struct task_struct *p)
2049{
2050        spin_lock(&p->alloc_lock);
2051}
2052
2053static inline void task_unlock(struct task_struct *p)
2054{
2055        spin_unlock(&p->alloc_lock);
2056}
2057
2058extern struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
2059                                                        unsigned long *flags);
2060
2061static inline void unlock_task_sighand(struct task_struct *tsk,
2062                                                unsigned long *flags)
2063{
2064        spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
2065}
2066
2067#ifndef __HAVE_THREAD_FUNCTIONS
2068
2069#define task_thread_info(task)  ((struct thread_info *)(task)->stack)
2070#define task_stack_page(task)   ((task)->stack)
2071
2072static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
2073{
2074        *task_thread_info(p) = *task_thread_info(org);
2075        task_thread_info(p)->task = p;
2076}
2077
2078static inline unsigned long *end_of_stack(struct task_struct *p)
2079{
2080        return (unsigned long *)(task_thread_info(p) + 1);
2081}
2082
2083#endif
2084
2085static inline int object_is_on_stack(void *obj)
2086{
2087        void *stack = task_stack_page(current);
2088
2089        return (obj >= stack) && (obj < (stack + THREAD_SIZE));
2090}
2091
2092extern void thread_info_cache_init(void);
2093
2094/* set thread flags in other task's structures
2095 * - see asm/thread_info.h for TIF_xxxx flags available
2096 */
2097static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2098{
2099        set_ti_thread_flag(task_thread_info(tsk), flag);
2100}
2101
2102static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2103{
2104        clear_ti_thread_flag(task_thread_info(tsk), flag);
2105}
2106
2107static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2108{
2109        return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2110}
2111
2112static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2113{
2114        return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2115}
2116
2117static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2118{
2119        return test_ti_thread_flag(task_thread_info(tsk), flag);
2120}
2121
2122static inline void set_tsk_need_resched(struct task_struct *tsk)
2123{
2124        set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2125}
2126
2127static inline void clear_tsk_need_resched(struct task_struct *tsk)
2128{
2129        clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2130}
2131
2132static inline int test_tsk_need_resched(struct task_struct *tsk)
2133{
2134        return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2135}
2136
2137static inline int signal_pending(struct task_struct *p)
2138{
2139        return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
2140}
2141
2142extern int __fatal_signal_pending(struct task_struct *p);
2143
2144static inline int fatal_signal_pending(struct task_struct *p)
2145{
2146        return signal_pending(p) && __fatal_signal_pending(p);
2147}
2148
2149static inline int signal_pending_state(long state, struct task_struct *p)
2150{
2151        if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
2152                return 0;
2153        if (!signal_pending(p))
2154                return 0;
2155
2156        return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
2157}
2158
2159static inline int need_resched(void)
2160{
2161        return unlikely(test_thread_flag(TIF_NEED_RESCHED));
2162}
2163
2164/*
2165 * cond_resched() and cond_resched_lock(): latency reduction via
2166 * explicit rescheduling in places that are safe. The return
2167 * value indicates whether a reschedule was done in fact.
2168 * cond_resched_lock() will drop the spinlock before scheduling,
2169 * cond_resched_softirq() will enable bhs before scheduling.
2170 */
2171extern int _cond_resched(void);
2172#ifdef CONFIG_PREEMPT_BKL
2173static inline int cond_resched(void)
2174{
2175        return 0;
2176}
2177#else
2178static inline int cond_resched(void)
2179{
2180        return _cond_resched();
2181}
2182#endif
2183extern int cond_resched_lock(spinlock_t * lock);
2184extern int cond_resched_softirq(void);
2185static inline int cond_resched_bkl(void)
2186{
2187        return _cond_resched();
2188}
2189
2190/*
2191 * Does a critical section need to be broken due to another
2192 * task waiting?: (technically does not depend on CONFIG_PREEMPT,
2193 * but a general need for low latency)
2194 */
2195static inline int spin_needbreak(spinlock_t *lock)
2196{
2197#ifdef CONFIG_PREEMPT
2198        return spin_is_contended(lock);
2199#else
2200        return 0;
2201#endif
2202}
2203
2204/*
2205 * Thread group CPU time accounting.
2206 */
2207void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
2208void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
2209
2210static inline void thread_group_cputime_init(struct signal_struct *sig)
2211{
2212        sig->cputimer.cputime = INIT_CPUTIME;
2213        spin_lock_init(&sig->cputimer.lock);
2214        sig->cputimer.running = 0;
2215}
2216
2217static inline void thread_group_cputime_free(struct signal_struct *sig)
2218{
2219}
2220
2221/*
2222 * Reevaluate whether the task has signals pending delivery.
2223 * Wake the task if so.
2224 * This is required every time the blocked sigset_t changes.
2225 * callers must hold sighand->siglock.
2226 */
2227extern void recalc_sigpending_and_wake(struct task_struct *t);
2228extern void recalc_sigpending(void);
2229
2230extern void signal_wake_up(struct task_struct *t, int resume_stopped);
2231
2232/*
2233 * Wrappers for p->thread_info->cpu access. No-op on UP.
2234 */
2235#ifdef CONFIG_SMP
2236
2237static inline unsigned int task_cpu(const struct task_struct *p)
2238{
2239        return task_thread_info(p)->cpu;
2240}
2241
2242extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2243
2244#else
2245
2246static inline unsigned int task_cpu(const struct task_struct *p)
2247{
2248        return 0;
2249}
2250
2251static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2252{
2253}
2254
2255#endif /* CONFIG_SMP */
2256
2257extern void arch_pick_mmap_layout(struct mm_struct *mm);
2258
2259#ifdef CONFIG_TRACING
2260extern void
2261__trace_special(void *__tr, void *__data,
2262                unsigned long arg1, unsigned long arg2, unsigned long arg3);
2263#else
2264static inline void
2265__trace_special(void *__tr, void *__data,
2266                unsigned long arg1, unsigned long arg2, unsigned long arg3)
2267{
2268}
2269#endif
2270
2271extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2272extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2273
2274extern void normalize_rt_tasks(void);
2275
2276#ifdef CONFIG_GROUP_SCHED
2277
2278extern struct task_group init_task_group;
2279#ifdef CONFIG_USER_SCHED
2280extern struct task_group root_task_group;
2281extern void set_tg_uid(struct user_struct *user);
2282#endif
2283
2284extern struct task_group *sched_create_group(struct task_group *parent);
2285extern void sched_destroy_group(struct task_group *tg);
2286extern void sched_move_task(struct task_struct *tsk);
2287#ifdef CONFIG_FAIR_GROUP_SCHED
2288extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
2289extern unsigned long sched_group_shares(struct task_group *tg);
2290#endif
2291#ifdef CONFIG_RT_GROUP_SCHED
2292extern int sched_group_set_rt_runtime(struct task_group *tg,
2293                                      long rt_runtime_us);
2294extern long sched_group_rt_runtime(struct task_group *tg);
2295extern int sched_group_set_rt_period(struct task_group *tg,
2296                                      long rt_period_us);
2297extern long sched_group_rt_period(struct task_group *tg);
2298extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk);
2299#endif
2300#endif
2301
2302extern int task_can_switch_user(struct user_struct *up,
2303                                        struct task_struct *tsk);
2304
2305#ifdef CONFIG_TASK_XACCT
2306static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2307{
2308        tsk->ioac.rchar += amt;
2309}
2310
2311static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2312{
2313        tsk->ioac.wchar += amt;
2314}
2315
2316static inline void inc_syscr(struct task_struct *tsk)
2317{
2318        tsk->ioac.syscr++;
2319}
2320
2321static inline void inc_syscw(struct task_struct *tsk)
2322{
2323        tsk->ioac.syscw++;
2324}
2325#else
2326static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2327{
2328}
2329
2330static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2331{
2332}
2333
2334static inline void inc_syscr(struct task_struct *tsk)
2335{
2336}
2337
2338static inline void inc_syscw(struct task_struct *tsk)
2339{
2340}
2341#endif
2342
2343#ifndef TASK_SIZE_OF
2344#define TASK_SIZE_OF(tsk)       TASK_SIZE
2345#endif
2346
2347#ifdef CONFIG_MM_OWNER
2348extern void mm_update_next_owner(struct mm_struct *mm);
2349extern void mm_init_owner(struct mm_struct *mm, struct task_struct *p);
2350#else
2351static inline void mm_update_next_owner(struct mm_struct *mm)
2352{
2353}
2354
2355static inline void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
2356{
2357}
2358#endif /* CONFIG_MM_OWNER */
2359
2360#define TASK_STATE_TO_CHAR_STR "RSDTtZX"
2361
2362#endif /* __KERNEL__ */
2363
2364#endif
2365