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/* 0x02000000 was previously the unused CLONE_STOPPED (Start in stopped state)
  25   and is now available for re-use. */
  26#define CLONE_NEWUTS            0x04000000      /* New utsname group? */
  27#define CLONE_NEWIPC            0x08000000      /* New ipcs */
  28#define CLONE_NEWUSER           0x10000000      /* New user namespace */
  29#define CLONE_NEWPID            0x20000000      /* New pid namespace */
  30#define CLONE_NEWNET            0x40000000      /* New network namespace */
  31#define CLONE_IO                0x80000000      /* Clone io context */
  32
  33/*
  34 * Scheduling policies
  35 */
  36#define SCHED_NORMAL            0
  37#define SCHED_FIFO              1
  38#define SCHED_RR                2
  39#define SCHED_BATCH             3
  40/* SCHED_ISO: reserved but not implemented yet */
  41#define SCHED_IDLE              5
  42/* Can be ORed in to make sure the process is reverted back to SCHED_NORMAL on fork */
  43#define SCHED_RESET_ON_FORK     0x40000000
  44
  45#ifdef __KERNEL__
  46
  47struct sched_param {
  48        int sched_priority;
  49};
  50
  51#include <asm/param.h>  /* for HZ */
  52
  53#include <linux/capability.h>
  54#include <linux/threads.h>
  55#include <linux/kernel.h>
  56#include <linux/types.h>
  57#include <linux/timex.h>
  58#include <linux/jiffies.h>
  59#include <linux/rbtree.h>
  60#include <linux/thread_info.h>
  61#include <linux/cpumask.h>
  62#include <linux/errno.h>
  63#include <linux/nodemask.h>
  64#include <linux/mm_types.h>
  65
  66#include <asm/system.h>
  67#include <asm/page.h>
  68#include <asm/ptrace.h>
  69#include <asm/cputime.h>
  70
  71#include <linux/smp.h>
  72#include <linux/sem.h>
  73#include <linux/signal.h>
  74#include <linux/compiler.h>
  75#include <linux/completion.h>
  76#include <linux/pid.h>
  77#include <linux/percpu.h>
  78#include <linux/topology.h>
  79#include <linux/proportions.h>
  80#include <linux/seccomp.h>
  81#include <linux/rcupdate.h>
  82#include <linux/rculist.h>
  83#include <linux/rtmutex.h>
  84
  85#include <linux/time.h>
  86#include <linux/param.h>
  87#include <linux/resource.h>
  88#include <linux/timer.h>
  89#include <linux/hrtimer.h>
  90#include <linux/task_io_accounting.h>
  91#include <linux/latencytop.h>
  92#include <linux/cred.h>
  93#include <linux/llist.h>
  94
  95#include <asm/processor.h>
  96
  97struct exec_domain;
  98struct futex_pi_state;
  99struct robust_list_head;
 100struct bio_list;
 101struct fs_struct;
 102struct perf_event_context;
 103struct blk_plug;
 104
 105/*
 106 * List of flags we want to share for kernel threads,
 107 * if only because they are not used by them anyway.
 108 */
 109#define CLONE_KERNEL    (CLONE_FS | CLONE_FILES | CLONE_SIGHAND)
 110
 111/*
 112 * These are the constant used to fake the fixed-point load-average
 113 * counting. Some notes:
 114 *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
 115 *    a load-average precision of 10 bits integer + 11 bits fractional
 116 *  - if you want to count load-averages more often, you need more
 117 *    precision, or rounding will get you. With 2-second counting freq,
 118 *    the EXP_n values would be 1981, 2034 and 2043 if still using only
 119 *    11 bit fractions.
 120 */
 121extern unsigned long avenrun[];         /* Load averages */
 122extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
 123
 124#define FSHIFT          11              /* nr of bits of precision */
 125#define FIXED_1         (1<<FSHIFT)     /* 1.0 as fixed-point */
 126#define LOAD_FREQ       (5*HZ+1)        /* 5 sec intervals */
 127#define EXP_1           1884            /* 1/exp(5sec/1min) as fixed-point */
 128#define EXP_5           2014            /* 1/exp(5sec/5min) */
 129#define EXP_15          2037            /* 1/exp(5sec/15min) */
 130
 131#define CALC_LOAD(load,exp,n) \
 132        load *= exp; \
 133        load += n*(FIXED_1-exp); \
 134        load >>= FSHIFT;
 135
 136extern unsigned long total_forks;
 137extern int nr_threads;
 138DECLARE_PER_CPU(unsigned long, process_counts);
 139extern int nr_processes(void);
 140extern unsigned long nr_running(void);
 141extern unsigned long nr_uninterruptible(void);
 142extern unsigned long nr_iowait(void);
 143extern unsigned long nr_iowait_cpu(int cpu);
 144extern unsigned long this_cpu_load(void);
 145
 146
 147extern void calc_global_load(unsigned long ticks);
 148
 149extern unsigned long get_parent_ip(unsigned long addr);
 150
 151struct seq_file;
 152struct cfs_rq;
 153struct task_group;
 154#ifdef CONFIG_SCHED_DEBUG
 155extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
 156extern void proc_sched_set_task(struct task_struct *p);
 157extern void
 158print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
 159#else
 160static inline void
 161proc_sched_show_task(struct task_struct *p, struct seq_file *m)
 162{
 163}
 164static inline void proc_sched_set_task(struct task_struct *p)
 165{
 166}
 167static inline void
 168print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
 169{
 170}
 171#endif
 172
 173/*
 174 * Task state bitmask. NOTE! These bits are also
 175 * encoded in fs/proc/array.c: get_task_state().
 176 *
 177 * We have two separate sets of flags: task->state
 178 * is about runnability, while task->exit_state are
 179 * about the task exiting. Confusing, but this way
 180 * modifying one set can't modify the other one by
 181 * mistake.
 182 */
 183#define TASK_RUNNING            0
 184#define TASK_INTERRUPTIBLE      1
 185#define TASK_UNINTERRUPTIBLE    2
 186#define __TASK_STOPPED          4
 187#define __TASK_TRACED           8
 188/* in tsk->exit_state */
 189#define EXIT_ZOMBIE             16
 190#define EXIT_DEAD               32
 191/* in tsk->state again */
 192#define TASK_DEAD               64
 193#define TASK_WAKEKILL           128
 194#define TASK_WAKING             256
 195#define TASK_STATE_MAX          512
 196
 197#define TASK_STATE_TO_CHAR_STR "RSDTtZXxKW"
 198
 199extern char ___assert_task_state[1 - 2*!!(
 200                sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
 201
 202/* Convenience macros for the sake of set_task_state */
 203#define TASK_KILLABLE           (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
 204#define TASK_STOPPED            (TASK_WAKEKILL | __TASK_STOPPED)
 205#define TASK_TRACED             (TASK_WAKEKILL | __TASK_TRACED)
 206
 207/* Convenience macros for the sake of wake_up */
 208#define TASK_NORMAL             (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
 209#define TASK_ALL                (TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
 210
 211/* get_task_state() */
 212#define TASK_REPORT             (TASK_RUNNING | TASK_INTERRUPTIBLE | \
 213                                 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
 214                                 __TASK_TRACED)
 215
 216#define task_is_traced(task)    ((task->state & __TASK_TRACED) != 0)
 217#define task_is_stopped(task)   ((task->state & __TASK_STOPPED) != 0)
 218#define task_is_dead(task)      ((task)->exit_state != 0)
 219#define task_is_stopped_or_traced(task) \
 220                        ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
 221#define task_contributes_to_load(task)  \
 222                                ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
 223                                 (task->flags & PF_FROZEN) == 0)
 224
 225#define __set_task_state(tsk, state_value)              \
 226        do { (tsk)->state = (state_value); } while (0)
 227#define set_task_state(tsk, state_value)                \
 228        set_mb((tsk)->state, (state_value))
 229
 230/*
 231 * set_current_state() includes a barrier so that the write of current->state
 232 * is correctly serialised wrt the caller's subsequent test of whether to
 233 * actually sleep:
 234 *
 235 *      set_current_state(TASK_UNINTERRUPTIBLE);
 236 *      if (do_i_need_to_sleep())
 237 *              schedule();
 238 *
 239 * If the caller does not need such serialisation then use __set_current_state()
 240 */
 241#define __set_current_state(state_value)                        \
 242        do { current->state = (state_value); } while (0)
 243#define set_current_state(state_value)          \
 244        set_mb(current->state, (state_value))
 245
 246/* Task command name length */
 247#define TASK_COMM_LEN 16
 248
 249#include <linux/spinlock.h>
 250
 251/*
 252 * This serializes "schedule()" and also protects
 253 * the run-queue from deletions/modifications (but
 254 * _adding_ to the beginning of the run-queue has
 255 * a separate lock).
 256 */
 257extern rwlock_t tasklist_lock;
 258extern spinlock_t mmlist_lock;
 259
 260struct task_struct;
 261
 262#ifdef CONFIG_PROVE_RCU
 263extern int lockdep_tasklist_lock_is_held(void);
 264#endif /* #ifdef CONFIG_PROVE_RCU */
 265
 266extern void sched_init(void);
 267extern void sched_init_smp(void);
 268extern asmlinkage void schedule_tail(struct task_struct *prev);
 269extern void init_idle(struct task_struct *idle, int cpu);
 270extern void init_idle_bootup_task(struct task_struct *idle);
 271
 272extern int runqueue_is_locked(int cpu);
 273
 274#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ)
 275extern void select_nohz_load_balancer(int stop_tick);
 276extern void set_cpu_sd_state_idle(void);
 277extern int get_nohz_timer_target(void);
 278#else
 279static inline void select_nohz_load_balancer(int stop_tick) { }
 280static inline void set_cpu_sd_state_idle(void) { }
 281#endif
 282
 283/*
 284 * Only dump TASK_* tasks. (0 for all tasks)
 285 */
 286extern void show_state_filter(unsigned long state_filter);
 287
 288static inline void show_state(void)
 289{
 290        show_state_filter(0);
 291}
 292
 293extern void show_regs(struct pt_regs *);
 294
 295/*
 296 * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
 297 * task), SP is the stack pointer of the first frame that should be shown in the back
 298 * trace (or NULL if the entire call-chain of the task should be shown).
 299 */
 300extern void show_stack(struct task_struct *task, unsigned long *sp);
 301
 302void io_schedule(void);
 303long io_schedule_timeout(long timeout);
 304
 305extern void cpu_init (void);
 306extern void trap_init(void);
 307extern void update_process_times(int user);
 308extern void scheduler_tick(void);
 309
 310extern void sched_show_task(struct task_struct *p);
 311
 312#ifdef CONFIG_LOCKUP_DETECTOR
 313extern void touch_softlockup_watchdog(void);
 314extern void touch_softlockup_watchdog_sync(void);
 315extern void touch_all_softlockup_watchdogs(void);
 316extern int proc_dowatchdog_thresh(struct ctl_table *table, int write,
 317                                  void __user *buffer,
 318                                  size_t *lenp, loff_t *ppos);
 319extern unsigned int  softlockup_panic;
 320void lockup_detector_init(void);
 321#else
 322static inline void touch_softlockup_watchdog(void)
 323{
 324}
 325static inline void touch_softlockup_watchdog_sync(void)
 326{
 327}
 328static inline void touch_all_softlockup_watchdogs(void)
 329{
 330}
 331static inline void lockup_detector_init(void)
 332{
 333}
 334#endif
 335
 336#ifdef CONFIG_DETECT_HUNG_TASK
 337extern unsigned int  sysctl_hung_task_panic;
 338extern unsigned long sysctl_hung_task_check_count;
 339extern unsigned long sysctl_hung_task_timeout_secs;
 340extern unsigned long sysctl_hung_task_warnings;
 341extern int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
 342                                         void __user *buffer,
 343                                         size_t *lenp, loff_t *ppos);
 344#else
 345/* Avoid need for ifdefs elsewhere in the code */
 346enum { sysctl_hung_task_timeout_secs = 0 };
 347#endif
 348
 349/* Attach to any functions which should be ignored in wchan output. */
 350#define __sched         __attribute__((__section__(".sched.text")))
 351
 352/* Linker adds these: start and end of __sched functions */
 353extern char __sched_text_start[], __sched_text_end[];
 354
 355/* Is this address in the __sched functions? */
 356extern int in_sched_functions(unsigned long addr);
 357
 358#define MAX_SCHEDULE_TIMEOUT    LONG_MAX
 359extern signed long schedule_timeout(signed long timeout);
 360extern signed long schedule_timeout_interruptible(signed long timeout);
 361extern signed long schedule_timeout_killable(signed long timeout);
 362extern signed long schedule_timeout_uninterruptible(signed long timeout);
 363asmlinkage void schedule(void);
 364extern int mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner);
 365
 366struct nsproxy;
 367struct user_namespace;
 368
 369/*
 370 * Default maximum number of active map areas, this limits the number of vmas
 371 * per mm struct. Users can overwrite this number by sysctl but there is a
 372 * problem.
 373 *
 374 * When a program's coredump is generated as ELF format, a section is created
 375 * per a vma. In ELF, the number of sections is represented in unsigned short.
 376 * This means the number of sections should be smaller than 65535 at coredump.
 377 * Because the kernel adds some informative sections to a image of program at
 378 * generating coredump, we need some margin. The number of extra sections is
 379 * 1-3 now and depends on arch. We use "5" as safe margin, here.
 380 */
 381#define MAPCOUNT_ELF_CORE_MARGIN        (5)
 382#define DEFAULT_MAX_MAP_COUNT   (USHRT_MAX - MAPCOUNT_ELF_CORE_MARGIN)
 383
 384extern int sysctl_max_map_count;
 385
 386#include <linux/aio.h>
 387
 388#ifdef CONFIG_MMU
 389extern void arch_pick_mmap_layout(struct mm_struct *mm);
 390extern unsigned long
 391arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
 392                       unsigned long, unsigned long);
 393extern unsigned long
 394arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
 395                          unsigned long len, unsigned long pgoff,
 396                          unsigned long flags);
 397extern void arch_unmap_area(struct mm_struct *, unsigned long);
 398extern void arch_unmap_area_topdown(struct mm_struct *, unsigned long);
 399#else
 400static inline void arch_pick_mmap_layout(struct mm_struct *mm) {}
 401#endif
 402
 403
 404extern void set_dumpable(struct mm_struct *mm, int value);
 405extern int get_dumpable(struct mm_struct *mm);
 406
 407/* mm flags */
 408/* dumpable bits */
 409#define MMF_DUMPABLE      0  /* core dump is permitted */
 410#define MMF_DUMP_SECURELY 1  /* core file is readable only by root */
 411
 412#define MMF_DUMPABLE_BITS 2
 413#define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
 414
 415/* coredump filter bits */
 416#define MMF_DUMP_ANON_PRIVATE   2
 417#define MMF_DUMP_ANON_SHARED    3
 418#define MMF_DUMP_MAPPED_PRIVATE 4
 419#define MMF_DUMP_MAPPED_SHARED  5
 420#define MMF_DUMP_ELF_HEADERS    6
 421#define MMF_DUMP_HUGETLB_PRIVATE 7
 422#define MMF_DUMP_HUGETLB_SHARED  8
 423
 424#define MMF_DUMP_FILTER_SHIFT   MMF_DUMPABLE_BITS
 425#define MMF_DUMP_FILTER_BITS    7
 426#define MMF_DUMP_FILTER_MASK \
 427        (((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
 428#define MMF_DUMP_FILTER_DEFAULT \
 429        ((1 << MMF_DUMP_ANON_PRIVATE) | (1 << MMF_DUMP_ANON_SHARED) |\
 430         (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
 431
 432#ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
 433# define MMF_DUMP_MASK_DEFAULT_ELF      (1 << MMF_DUMP_ELF_HEADERS)
 434#else
 435# define MMF_DUMP_MASK_DEFAULT_ELF      0
 436#endif
 437                                        /* leave room for more dump flags */
 438#define MMF_VM_MERGEABLE        16      /* KSM may merge identical pages */
 439#define MMF_VM_HUGEPAGE         17      /* set when VM_HUGEPAGE is set on vma */
 440
 441#define MMF_INIT_MASK           (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
 442
 443struct sighand_struct {
 444        atomic_t                count;
 445        struct k_sigaction      action[_NSIG];
 446        spinlock_t              siglock;
 447        wait_queue_head_t       signalfd_wqh;
 448};
 449
 450struct pacct_struct {
 451        int                     ac_flag;
 452        long                    ac_exitcode;
 453        unsigned long           ac_mem;
 454        cputime_t               ac_utime, ac_stime;
 455        unsigned long           ac_minflt, ac_majflt;
 456};
 457
 458struct cpu_itimer {
 459        cputime_t expires;
 460        cputime_t incr;
 461        u32 error;
 462        u32 incr_error;
 463};
 464
 465/**
 466 * struct task_cputime - collected CPU time counts
 467 * @utime:              time spent in user mode, in &cputime_t units
 468 * @stime:              time spent in kernel mode, in &cputime_t units
 469 * @sum_exec_runtime:   total time spent on the CPU, in nanoseconds
 470 *
 471 * This structure groups together three kinds of CPU time that are
 472 * tracked for threads and thread groups.  Most things considering
 473 * CPU time want to group these counts together and treat all three
 474 * of them in parallel.
 475 */
 476struct task_cputime {
 477        cputime_t utime;
 478        cputime_t stime;
 479        unsigned long long sum_exec_runtime;
 480};
 481/* Alternate field names when used to cache expirations. */
 482#define prof_exp        stime
 483#define virt_exp        utime
 484#define sched_exp       sum_exec_runtime
 485
 486#define INIT_CPUTIME    \
 487        (struct task_cputime) {                                 \
 488                .utime = 0,                                     \
 489                .stime = 0,                                     \
 490                .sum_exec_runtime = 0,                          \
 491        }
 492
 493/*
 494 * Disable preemption until the scheduler is running.
 495 * Reset by start_kernel()->sched_init()->init_idle().
 496 *
 497 * We include PREEMPT_ACTIVE to avoid cond_resched() from working
 498 * before the scheduler is active -- see should_resched().
 499 */
 500#define INIT_PREEMPT_COUNT      (1 + PREEMPT_ACTIVE)
 501
 502/**
 503 * struct thread_group_cputimer - thread group interval timer counts
 504 * @cputime:            thread group interval timers.
 505 * @running:            non-zero when there are timers running and
 506 *                      @cputime receives updates.
 507 * @lock:               lock for fields in this struct.
 508 *
 509 * This structure contains the version of task_cputime, above, that is
 510 * used for thread group CPU timer calculations.
 511 */
 512struct thread_group_cputimer {
 513        struct task_cputime cputime;
 514        int running;
 515        raw_spinlock_t lock;
 516};
 517
 518#include <linux/rwsem.h>
 519struct autogroup;
 520
 521/*
 522 * NOTE! "signal_struct" does not have its own
 523 * locking, because a shared signal_struct always
 524 * implies a shared sighand_struct, so locking
 525 * sighand_struct is always a proper superset of
 526 * the locking of signal_struct.
 527 */
 528struct signal_struct {
 529        atomic_t                sigcnt;
 530        atomic_t                live;
 531        int                     nr_threads;
 532
 533        wait_queue_head_t       wait_chldexit;  /* for wait4() */
 534
 535        /* current thread group signal load-balancing target: */
 536        struct task_struct      *curr_target;
 537
 538        /* shared signal handling: */
 539        struct sigpending       shared_pending;
 540
 541        /* thread group exit support */
 542        int                     group_exit_code;
 543        /* overloaded:
 544         * - notify group_exit_task when ->count is equal to notify_count
 545         * - everyone except group_exit_task is stopped during signal delivery
 546         *   of fatal signals, group_exit_task processes the signal.
 547         */
 548        int                     notify_count;
 549        struct task_struct      *group_exit_task;
 550
 551        /* thread group stop support, overloads group_exit_code too */
 552        int                     group_stop_count;
 553        unsigned int            flags; /* see SIGNAL_* flags below */
 554
 555        /* POSIX.1b Interval Timers */
 556        struct list_head posix_timers;
 557
 558        /* ITIMER_REAL timer for the process */
 559        struct hrtimer real_timer;
 560        struct pid *leader_pid;
 561        ktime_t it_real_incr;
 562
 563        /*
 564         * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
 565         * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
 566         * values are defined to 0 and 1 respectively
 567         */
 568        struct cpu_itimer it[2];
 569
 570        /*
 571         * Thread group totals for process CPU timers.
 572         * See thread_group_cputimer(), et al, for details.
 573         */
 574        struct thread_group_cputimer cputimer;
 575
 576        /* Earliest-expiration cache. */
 577        struct task_cputime cputime_expires;
 578
 579        struct list_head cpu_timers[3];
 580
 581        struct pid *tty_old_pgrp;
 582
 583        /* boolean value for session group leader */
 584        int leader;
 585
 586        struct tty_struct *tty; /* NULL if no tty */
 587
 588#ifdef CONFIG_SCHED_AUTOGROUP
 589        struct autogroup *autogroup;
 590#endif
 591        /*
 592         * Cumulative resource counters for dead threads in the group,
 593         * and for reaped dead child processes forked by this group.
 594         * Live threads maintain their own counters and add to these
 595         * in __exit_signal, except for the group leader.
 596         */
 597        cputime_t utime, stime, cutime, cstime;
 598        cputime_t gtime;
 599        cputime_t cgtime;
 600#ifndef CONFIG_VIRT_CPU_ACCOUNTING
 601        cputime_t prev_utime, prev_stime;
 602#endif
 603        unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
 604        unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
 605        unsigned long inblock, oublock, cinblock, coublock;
 606        unsigned long maxrss, cmaxrss;
 607        struct task_io_accounting ioac;
 608
 609        /*
 610         * Cumulative ns of schedule CPU time fo dead threads in the
 611         * group, not including a zombie group leader, (This only differs
 612         * from jiffies_to_ns(utime + stime) if sched_clock uses something
 613         * other than jiffies.)
 614         */
 615        unsigned long long sum_sched_runtime;
 616
 617        /*
 618         * We don't bother to synchronize most readers of this at all,
 619         * because there is no reader checking a limit that actually needs
 620         * to get both rlim_cur and rlim_max atomically, and either one
 621         * alone is a single word that can safely be read normally.
 622         * getrlimit/setrlimit use task_lock(current->group_leader) to
 623         * protect this instead of the siglock, because they really
 624         * have no need to disable irqs.
 625         */
 626        struct rlimit rlim[RLIM_NLIMITS];
 627
 628#ifdef CONFIG_BSD_PROCESS_ACCT
 629        struct pacct_struct pacct;      /* per-process accounting information */
 630#endif
 631#ifdef CONFIG_TASKSTATS
 632        struct taskstats *stats;
 633#endif
 634#ifdef CONFIG_AUDIT
 635        unsigned audit_tty;
 636        struct tty_audit_buf *tty_audit_buf;
 637#endif
 638#ifdef CONFIG_CGROUPS
 639        /*
 640         * group_rwsem prevents new tasks from entering the threadgroup and
 641         * member tasks from exiting,a more specifically, setting of
 642         * PF_EXITING.  fork and exit paths are protected with this rwsem
 643         * using threadgroup_change_begin/end().  Users which require
 644         * threadgroup to remain stable should use threadgroup_[un]lock()
 645         * which also takes care of exec path.  Currently, cgroup is the
 646         * only user.
 647         */
 648        struct rw_semaphore group_rwsem;
 649#endif
 650
 651        int oom_adj;            /* OOM kill score adjustment (bit shift) */
 652        int oom_score_adj;      /* OOM kill score adjustment */
 653        int oom_score_adj_min;  /* OOM kill score adjustment minimum value.
 654                                 * Only settable by CAP_SYS_RESOURCE. */
 655
 656        struct mutex cred_guard_mutex;  /* guard against foreign influences on
 657                                         * credential calculations
 658                                         * (notably. ptrace) */
 659};
 660
 661/* Context switch must be unlocked if interrupts are to be enabled */
 662#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
 663# define __ARCH_WANT_UNLOCKED_CTXSW
 664#endif
 665
 666/*
 667 * Bits in flags field of signal_struct.
 668 */
 669#define SIGNAL_STOP_STOPPED     0x00000001 /* job control stop in effect */
 670#define SIGNAL_STOP_CONTINUED   0x00000002 /* SIGCONT since WCONTINUED reap */
 671#define SIGNAL_GROUP_EXIT       0x00000004 /* group exit in progress */
 672/*
 673 * Pending notifications to parent.
 674 */
 675#define SIGNAL_CLD_STOPPED      0x00000010
 676#define SIGNAL_CLD_CONTINUED    0x00000020
 677#define SIGNAL_CLD_MASK         (SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
 678
 679#define SIGNAL_UNKILLABLE       0x00000040 /* for init: ignore fatal signals */
 680
 681/* If true, all threads except ->group_exit_task have pending SIGKILL */
 682static inline int signal_group_exit(const struct signal_struct *sig)
 683{
 684        return  (sig->flags & SIGNAL_GROUP_EXIT) ||
 685                (sig->group_exit_task != NULL);
 686}
 687
 688/*
 689 * Some day this will be a full-fledged user tracking system..
 690 */
 691struct user_struct {
 692        atomic_t __count;       /* reference count */
 693        atomic_t processes;     /* How many processes does this user have? */
 694        atomic_t files;         /* How many open files does this user have? */
 695        atomic_t sigpending;    /* How many pending signals does this user have? */
 696#ifdef CONFIG_INOTIFY_USER
 697        atomic_t inotify_watches; /* How many inotify watches does this user have? */
 698        atomic_t inotify_devs;  /* How many inotify devs does this user have opened? */
 699#endif
 700#ifdef CONFIG_FANOTIFY
 701        atomic_t fanotify_listeners;
 702#endif
 703#ifdef CONFIG_EPOLL
 704        atomic_long_t epoll_watches; /* The number of file descriptors currently watched */
 705#endif
 706#ifdef CONFIG_POSIX_MQUEUE
 707        /* protected by mq_lock */
 708        unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */
 709#endif
 710        unsigned long locked_shm; /* How many pages of mlocked shm ? */
 711
 712#ifdef CONFIG_KEYS
 713        struct key *uid_keyring;        /* UID specific keyring */
 714        struct key *session_keyring;    /* UID's default session keyring */
 715#endif
 716
 717        /* Hash table maintenance information */
 718        struct hlist_node uidhash_node;
 719        uid_t uid;
 720        struct user_namespace *user_ns;
 721
 722#ifdef CONFIG_PERF_EVENTS
 723        atomic_long_t locked_vm;
 724#endif
 725};
 726
 727extern int uids_sysfs_init(void);
 728
 729extern struct user_struct *find_user(uid_t);
 730
 731extern struct user_struct root_user;
 732#define INIT_USER (&root_user)
 733
 734
 735struct backing_dev_info;
 736struct reclaim_state;
 737
 738#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
 739struct sched_info {
 740        /* cumulative counters */
 741        unsigned long pcount;         /* # of times run on this cpu */
 742        unsigned long long run_delay; /* time spent waiting on a runqueue */
 743
 744        /* timestamps */
 745        unsigned long long last_arrival,/* when we last ran on a cpu */
 746                           last_queued; /* when we were last queued to run */
 747};
 748#endif /* defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) */
 749
 750#ifdef CONFIG_TASK_DELAY_ACCT
 751struct task_delay_info {
 752        spinlock_t      lock;
 753        unsigned int    flags;  /* Private per-task flags */
 754
 755        /* For each stat XXX, add following, aligned appropriately
 756         *
 757         * struct timespec XXX_start, XXX_end;
 758         * u64 XXX_delay;
 759         * u32 XXX_count;
 760         *
 761         * Atomicity of updates to XXX_delay, XXX_count protected by
 762         * single lock above (split into XXX_lock if contention is an issue).
 763         */
 764
 765        /*
 766         * XXX_count is incremented on every XXX operation, the delay
 767         * associated with the operation is added to XXX_delay.
 768         * XXX_delay contains the accumulated delay time in nanoseconds.
 769         */
 770        struct timespec blkio_start, blkio_end; /* Shared by blkio, swapin */
 771        u64 blkio_delay;        /* wait for sync block io completion */
 772        u64 swapin_delay;       /* wait for swapin block io completion */
 773        u32 blkio_count;        /* total count of the number of sync block */
 774                                /* io operations performed */
 775        u32 swapin_count;       /* total count of the number of swapin block */
 776                                /* io operations performed */
 777
 778        struct timespec freepages_start, freepages_end;
 779        u64 freepages_delay;    /* wait for memory reclaim */
 780        u32 freepages_count;    /* total count of memory reclaim */
 781};
 782#endif  /* CONFIG_TASK_DELAY_ACCT */
 783
 784static inline int sched_info_on(void)
 785{
 786#ifdef CONFIG_SCHEDSTATS
 787        return 1;
 788#elif defined(CONFIG_TASK_DELAY_ACCT)
 789        extern int delayacct_on;
 790        return delayacct_on;
 791#else
 792        return 0;
 793#endif
 794}
 795
 796enum cpu_idle_type {
 797        CPU_IDLE,
 798        CPU_NOT_IDLE,
 799        CPU_NEWLY_IDLE,
 800        CPU_MAX_IDLE_TYPES
 801};
 802
 803/*
 804 * Increase resolution of nice-level calculations for 64-bit architectures.
 805 * The extra resolution improves shares distribution and load balancing of
 806 * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup
 807 * hierarchies, especially on larger systems. This is not a user-visible change
 808 * and does not change the user-interface for setting shares/weights.
 809 *
 810 * We increase resolution only if we have enough bits to allow this increased
 811 * resolution (i.e. BITS_PER_LONG > 32). The costs for increasing resolution
 812 * when BITS_PER_LONG <= 32 are pretty high and the returns do not justify the
 813 * increased costs.
 814 */
 815#if 0 /* BITS_PER_LONG > 32 -- currently broken: it increases power usage under light load  */
 816# define SCHED_LOAD_RESOLUTION  10
 817# define scale_load(w)          ((w) << SCHED_LOAD_RESOLUTION)
 818# define scale_load_down(w)     ((w) >> SCHED_LOAD_RESOLUTION)
 819#else
 820# define SCHED_LOAD_RESOLUTION  0
 821# define scale_load(w)          (w)
 822# define scale_load_down(w)     (w)
 823#endif
 824
 825#define SCHED_LOAD_SHIFT        (10 + SCHED_LOAD_RESOLUTION)
 826#define SCHED_LOAD_SCALE        (1L << SCHED_LOAD_SHIFT)
 827
 828/*
 829 * Increase resolution of cpu_power calculations
 830 */
 831#define SCHED_POWER_SHIFT       10
 832#define SCHED_POWER_SCALE       (1L << SCHED_POWER_SHIFT)
 833
 834/*
 835 * sched-domains (multiprocessor balancing) declarations:
 836 */
 837#ifdef CONFIG_SMP
 838#define SD_LOAD_BALANCE         0x0001  /* Do load balancing on this domain. */
 839#define SD_BALANCE_NEWIDLE      0x0002  /* Balance when about to become idle */
 840#define SD_BALANCE_EXEC         0x0004  /* Balance on exec */
 841#define SD_BALANCE_FORK         0x0008  /* Balance on fork, clone */
 842#define SD_BALANCE_WAKE         0x0010  /* Balance on wakeup */
 843#define SD_WAKE_AFFINE          0x0020  /* Wake task to waking CPU */
 844#define SD_PREFER_LOCAL         0x0040  /* Prefer to keep tasks local to this domain */
 845#define SD_SHARE_CPUPOWER       0x0080  /* Domain members share cpu power */
 846#define SD_POWERSAVINGS_BALANCE 0x0100  /* Balance for power savings */
 847#define SD_SHARE_PKG_RESOURCES  0x0200  /* Domain members share cpu pkg resources */
 848#define SD_SERIALIZE            0x0400  /* Only a single load balancing instance */
 849#define SD_ASYM_PACKING         0x0800  /* Place busy groups earlier in the domain */
 850#define SD_PREFER_SIBLING       0x1000  /* Prefer to place tasks in a sibling domain */
 851#define SD_OVERLAP              0x2000  /* sched_domains of this level overlap */
 852
 853enum powersavings_balance_level {
 854        POWERSAVINGS_BALANCE_NONE = 0,  /* No power saving load balance */
 855        POWERSAVINGS_BALANCE_BASIC,     /* Fill one thread/core/package
 856                                         * first for long running threads
 857                                         */
 858        POWERSAVINGS_BALANCE_WAKEUP,    /* Also bias task wakeups to semi-idle
 859                                         * cpu package for power savings
 860                                         */
 861        MAX_POWERSAVINGS_BALANCE_LEVELS
 862};
 863
 864extern int sched_mc_power_savings, sched_smt_power_savings;
 865
 866static inline int sd_balance_for_mc_power(void)
 867{
 868        if (sched_smt_power_savings)
 869                return SD_POWERSAVINGS_BALANCE;
 870
 871        if (!sched_mc_power_savings)
 872                return SD_PREFER_SIBLING;
 873
 874        return 0;
 875}
 876
 877static inline int sd_balance_for_package_power(void)
 878{
 879        if (sched_mc_power_savings | sched_smt_power_savings)
 880                return SD_POWERSAVINGS_BALANCE;
 881
 882        return SD_PREFER_SIBLING;
 883}
 884
 885extern int __weak arch_sd_sibiling_asym_packing(void);
 886
 887/*
 888 * Optimise SD flags for power savings:
 889 * SD_BALANCE_NEWIDLE helps aggressive task consolidation and power savings.
 890 * Keep default SD flags if sched_{smt,mc}_power_saving=0
 891 */
 892
 893static inline int sd_power_saving_flags(void)
 894{
 895        if (sched_mc_power_savings | sched_smt_power_savings)
 896                return SD_BALANCE_NEWIDLE;
 897
 898        return 0;
 899}
 900
 901struct sched_group_power {
 902        atomic_t ref;
 903        /*
 904         * CPU power of this group, SCHED_LOAD_SCALE being max power for a
 905         * single CPU.
 906         */
 907        unsigned int power, power_orig;
 908        /*
 909         * Number of busy cpus in this group.
 910         */
 911        atomic_t nr_busy_cpus;
 912};
 913
 914struct sched_group {
 915        struct sched_group *next;       /* Must be a circular list */
 916        atomic_t ref;
 917
 918        unsigned int group_weight;
 919        struct sched_group_power *sgp;
 920
 921        /*
 922         * The CPUs this group covers.
 923         *
 924         * NOTE: this field is variable length. (Allocated dynamically
 925         * by attaching extra space to the end of the structure,
 926         * depending on how many CPUs the kernel has booted up with)
 927         */
 928        unsigned long cpumask[0];
 929};
 930
 931static inline struct cpumask *sched_group_cpus(struct sched_group *sg)
 932{
 933        return to_cpumask(sg->cpumask);
 934}
 935
 936/**
 937 * group_first_cpu - Returns the first cpu in the cpumask of a sched_group.
 938 * @group: The group whose first cpu is to be returned.
 939 */
 940static inline unsigned int group_first_cpu(struct sched_group *group)
 941{
 942        return cpumask_first(sched_group_cpus(group));
 943}
 944
 945struct sched_domain_attr {
 946        int relax_domain_level;
 947};
 948
 949#define SD_ATTR_INIT    (struct sched_domain_attr) {    \
 950        .relax_domain_level = -1,                       \
 951}
 952
 953extern int sched_domain_level_max;
 954
 955struct sched_domain {
 956        /* These fields must be setup */
 957        struct sched_domain *parent;    /* top domain must be null terminated */
 958        struct sched_domain *child;     /* bottom domain must be null terminated */
 959        struct sched_group *groups;     /* the balancing groups of the domain */
 960        unsigned long min_interval;     /* Minimum balance interval ms */
 961        unsigned long max_interval;     /* Maximum balance interval ms */
 962        unsigned int busy_factor;       /* less balancing by factor if busy */
 963        unsigned int imbalance_pct;     /* No balance until over watermark */
 964        unsigned int cache_nice_tries;  /* Leave cache hot tasks for # tries */
 965        unsigned int busy_idx;
 966        unsigned int idle_idx;
 967        unsigned int newidle_idx;
 968        unsigned int wake_idx;
 969        unsigned int forkexec_idx;
 970        unsigned int smt_gain;
 971        int flags;                      /* See SD_* */
 972        int level;
 973
 974        /* Runtime fields. */
 975        unsigned long last_balance;     /* init to jiffies. units in jiffies */
 976        unsigned int balance_interval;  /* initialise to 1. units in ms. */
 977        unsigned int nr_balance_failed; /* initialise to 0 */
 978
 979        u64 last_update;
 980
 981#ifdef CONFIG_SCHEDSTATS
 982        /* load_balance() stats */
 983        unsigned int lb_count[CPU_MAX_IDLE_TYPES];
 984        unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
 985        unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
 986        unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
 987        unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
 988        unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
 989        unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
 990        unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
 991
 992        /* Active load balancing */
 993        unsigned int alb_count;
 994        unsigned int alb_failed;
 995        unsigned int alb_pushed;
 996
 997        /* SD_BALANCE_EXEC stats */
 998        unsigned int sbe_count;
 999        unsigned int sbe_balanced;
1000        unsigned int sbe_pushed;
1001
1002        /* SD_BALANCE_FORK stats */
1003        unsigned int sbf_count;
1004        unsigned int sbf_balanced;
1005        unsigned int sbf_pushed;
1006
1007        /* try_to_wake_up() stats */
1008        unsigned int ttwu_wake_remote;
1009        unsigned int ttwu_move_affine;
1010        unsigned int ttwu_move_balance;
1011#endif
1012#ifdef CONFIG_SCHED_DEBUG
1013        char *name;
1014#endif
1015        union {
1016                void *private;          /* used during construction */
1017                struct rcu_head rcu;    /* used during destruction */
1018        };
1019
1020        unsigned int span_weight;
1021        /*
1022         * Span of all CPUs in this domain.
1023         *
1024         * NOTE: this field is variable length. (Allocated dynamically
1025         * by attaching extra space to the end of the structure,
1026         * depending on how many CPUs the kernel has booted up with)
1027         */
1028        unsigned long span[0];
1029};
1030
1031static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
1032{
1033        return to_cpumask(sd->span);
1034}
1035
1036extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1037                                    struct sched_domain_attr *dattr_new);
1038
1039/* Allocate an array of sched domains, for partition_sched_domains(). */
1040cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
1041void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
1042
1043/* Test a flag in parent sched domain */
1044static inline int test_sd_parent(struct sched_domain *sd, int flag)
1045{
1046        if (sd->parent && (sd->parent->flags & flag))
1047                return 1;
1048
1049        return 0;
1050}
1051
1052unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu);
1053unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu);
1054
1055#else /* CONFIG_SMP */
1056
1057struct sched_domain_attr;
1058
1059static inline void
1060partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1061                        struct sched_domain_attr *dattr_new)
1062{
1063}
1064#endif  /* !CONFIG_SMP */
1065
1066
1067struct io_context;                      /* See blkdev.h */
1068
1069
1070#ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
1071extern void prefetch_stack(struct task_struct *t);
1072#else
1073static inline void prefetch_stack(struct task_struct *t) { }
1074#endif
1075
1076struct audit_context;           /* See audit.c */
1077struct mempolicy;
1078struct pipe_inode_info;
1079struct uts_namespace;
1080
1081struct rq;
1082struct sched_domain;
1083
1084/*
1085 * wake flags
1086 */
1087#define WF_SYNC         0x01            /* waker goes to sleep after wakup */
1088#define WF_FORK         0x02            /* child wakeup after fork */
1089#define WF_MIGRATED     0x04            /* internal use, task got migrated */
1090
1091#define ENQUEUE_WAKEUP          1
1092#define ENQUEUE_HEAD            2
1093#ifdef CONFIG_SMP
1094#define ENQUEUE_WAKING          4       /* sched_class::task_waking was called */
1095#else
1096#define ENQUEUE_WAKING          0
1097#endif
1098
1099#define DEQUEUE_SLEEP           1
1100
1101struct sched_class {
1102        const struct sched_class *next;
1103
1104        void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags);
1105        void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags);
1106        void (*yield_task) (struct rq *rq);
1107        bool (*yield_to_task) (struct rq *rq, struct task_struct *p, bool preempt);
1108
1109        void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags);
1110
1111        struct task_struct * (*pick_next_task) (struct rq *rq);
1112        void (*put_prev_task) (struct rq *rq, struct task_struct *p);
1113
1114#ifdef CONFIG_SMP
1115        int  (*select_task_rq)(struct task_struct *p, int sd_flag, int flags);
1116
1117        void (*pre_schedule) (struct rq *this_rq, struct task_struct *task);
1118        void (*post_schedule) (struct rq *this_rq);
1119        void (*task_waking) (struct task_struct *task);
1120        void (*task_woken) (struct rq *this_rq, struct task_struct *task);
1121
1122        void (*set_cpus_allowed)(struct task_struct *p,
1123                                 const struct cpumask *newmask);
1124
1125        void (*rq_online)(struct rq *rq);
1126        void (*rq_offline)(struct rq *rq);
1127#endif
1128
1129        void (*set_curr_task) (struct rq *rq);
1130        void (*task_tick) (struct rq *rq, struct task_struct *p, int queued);
1131        void (*task_fork) (struct task_struct *p);
1132
1133        void (*switched_from) (struct rq *this_rq, struct task_struct *task);
1134        void (*switched_to) (struct rq *this_rq, struct task_struct *task);
1135        void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
1136                             int oldprio);
1137
1138        unsigned int (*get_rr_interval) (struct rq *rq,
1139                                         struct task_struct *task);
1140
1141#ifdef CONFIG_FAIR_GROUP_SCHED
1142        void (*task_move_group) (struct task_struct *p, int on_rq);
1143#endif
1144};
1145
1146struct load_weight {
1147        unsigned long weight, inv_weight;
1148};
1149
1150#ifdef CONFIG_SCHEDSTATS
1151struct sched_statistics {
1152        u64                     wait_start;
1153        u64                     wait_max;
1154        u64                     wait_count;
1155        u64                     wait_sum;
1156        u64                     iowait_count;
1157        u64                     iowait_sum;
1158
1159        u64                     sleep_start;
1160        u64                     sleep_max;
1161        s64                     sum_sleep_runtime;
1162
1163        u64                     block_start;
1164        u64                     block_max;
1165        u64                     exec_max;
1166        u64                     slice_max;
1167
1168        u64                     nr_migrations_cold;
1169        u64                     nr_failed_migrations_affine;
1170        u64                     nr_failed_migrations_running;
1171        u64                     nr_failed_migrations_hot;
1172        u64                     nr_forced_migrations;
1173
1174        u64                     nr_wakeups;
1175        u64                     nr_wakeups_sync;
1176        u64                     nr_wakeups_migrate;
1177        u64                     nr_wakeups_local;
1178        u64                     nr_wakeups_remote;
1179        u64                     nr_wakeups_affine;
1180        u64                     nr_wakeups_affine_attempts;
1181        u64                     nr_wakeups_passive;
1182        u64                     nr_wakeups_idle;
1183};
1184#endif
1185
1186struct sched_entity {
1187        struct load_weight      load;           /* for load-balancing */
1188        struct rb_node          run_node;
1189        struct list_head        group_node;
1190        unsigned int            on_rq;
1191
1192        u64                     exec_start;
1193        u64                     sum_exec_runtime;
1194        u64                     vruntime;
1195        u64                     prev_sum_exec_runtime;
1196
1197        u64                     nr_migrations;
1198
1199#ifdef CONFIG_SCHEDSTATS
1200        struct sched_statistics statistics;
1201#endif
1202
1203#ifdef CONFIG_FAIR_GROUP_SCHED
1204        struct sched_entity     *parent;
1205        /* rq on which this entity is (to be) queued: */
1206        struct cfs_rq           *cfs_rq;
1207        /* rq "owned" by this entity/group: */
1208        struct cfs_rq           *my_q;
1209#endif
1210};
1211
1212struct sched_rt_entity {
1213        struct list_head run_list;
1214        unsigned long timeout;
1215        unsigned int time_slice;
1216        int nr_cpus_allowed;
1217
1218        struct sched_rt_entity *back;
1219#ifdef CONFIG_RT_GROUP_SCHED
1220        struct sched_rt_entity  *parent;
1221        /* rq on which this entity is (to be) queued: */
1222        struct rt_rq            *rt_rq;
1223        /* rq "owned" by this entity/group: */
1224        struct rt_rq            *my_q;
1225#endif
1226};
1227
1228struct rcu_node;
1229
1230enum perf_event_task_context {
1231        perf_invalid_context = -1,
1232        perf_hw_context = 0,
1233        perf_sw_context,
1234        perf_nr_task_contexts,
1235};
1236
1237struct task_struct {
1238        volatile long state;    /* -1 unrunnable, 0 runnable, >0 stopped */
1239        void *stack;
1240        atomic_t usage;
1241        unsigned int flags;     /* per process flags, defined below */
1242        unsigned int ptrace;
1243
1244#ifdef CONFIG_SMP
1245        struct llist_node wake_entry;
1246        int on_cpu;
1247#endif
1248        int on_rq;
1249
1250        int prio, static_prio, normal_prio;
1251        unsigned int rt_priority;
1252        const struct sched_class *sched_class;
1253        struct sched_entity se;
1254        struct sched_rt_entity rt;
1255
1256#ifdef CONFIG_PREEMPT_NOTIFIERS
1257        /* list of struct preempt_notifier: */
1258        struct hlist_head preempt_notifiers;
1259#endif
1260
1261        /*
1262         * fpu_counter contains the number of consecutive context switches
1263         * that the FPU is used. If this is over a threshold, the lazy fpu
1264         * saving becomes unlazy to save the trap. This is an unsigned char
1265         * so that after 256 times the counter wraps and the behavior turns
1266         * lazy again; this to deal with bursty apps that only use FPU for
1267         * a short time
1268         */
1269        unsigned char fpu_counter;
1270#ifdef CONFIG_BLK_DEV_IO_TRACE
1271        unsigned int btrace_seq;
1272#endif
1273
1274        unsigned int policy;
1275        cpumask_t cpus_allowed;
1276
1277#ifdef CONFIG_PREEMPT_RCU
1278        int rcu_read_lock_nesting;
1279        char rcu_read_unlock_special;
1280        struct list_head rcu_node_entry;
1281#endif /* #ifdef CONFIG_PREEMPT_RCU */
1282#ifdef CONFIG_TREE_PREEMPT_RCU
1283        struct rcu_node *rcu_blocked_node;
1284#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
1285#ifdef CONFIG_RCU_BOOST
1286        struct rt_mutex *rcu_boost_mutex;
1287#endif /* #ifdef CONFIG_RCU_BOOST */
1288
1289#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
1290        struct sched_info sched_info;
1291#endif
1292
1293        struct list_head tasks;
1294#ifdef CONFIG_SMP
1295        struct plist_node pushable_tasks;
1296#endif
1297
1298        struct mm_struct *mm, *active_mm;
1299#ifdef CONFIG_COMPAT_BRK
1300        unsigned brk_randomized:1;
1301#endif
1302#if defined(SPLIT_RSS_COUNTING)
1303        struct task_rss_stat    rss_stat;
1304#endif
1305/* task state */
1306        int exit_state;
1307        int exit_code, exit_signal;
1308        int pdeath_signal;  /*  The signal sent when the parent dies  */
1309        unsigned int jobctl;    /* JOBCTL_*, siglock protected */
1310        /* ??? */
1311        unsigned int personality;
1312        unsigned did_exec:1;
1313        unsigned in_execve:1;   /* Tell the LSMs that the process is doing an
1314                                 * execve */
1315        unsigned in_iowait:1;
1316
1317
1318        /* Revert to default priority/policy when forking */
1319        unsigned sched_reset_on_fork:1;
1320        unsigned sched_contributes_to_load:1;
1321
1322        pid_t pid;
1323        pid_t tgid;
1324
1325#ifdef CONFIG_CC_STACKPROTECTOR
1326        /* Canary value for the -fstack-protector gcc feature */
1327        unsigned long stack_canary;
1328#endif
1329
1330        /* 
1331         * pointers to (original) parent process, youngest child, younger sibling,
1332         * older sibling, respectively.  (p->father can be replaced with 
1333         * p->real_parent->pid)
1334         */
1335        struct task_struct __rcu *real_parent; /* real parent process */
1336        struct task_struct __rcu *parent; /* recipient of SIGCHLD, wait4() reports */
1337        /*
1338         * children/sibling forms the list of my natural children
1339         */
1340        struct list_head children;      /* list of my children */
1341        struct list_head sibling;       /* linkage in my parent's children list */
1342        struct task_struct *group_leader;       /* threadgroup leader */
1343
1344        /*
1345         * ptraced is the list of tasks this task is using ptrace on.
1346         * This includes both natural children and PTRACE_ATTACH targets.
1347         * p->ptrace_entry is p's link on the p->parent->ptraced list.
1348         */
1349        struct list_head ptraced;
1350        struct list_head ptrace_entry;
1351
1352        /* PID/PID hash table linkage. */
1353        struct pid_link pids[PIDTYPE_MAX];
1354        struct list_head thread_group;
1355
1356        struct completion *vfork_done;          /* for vfork() */
1357        int __user *set_child_tid;              /* CLONE_CHILD_SETTID */
1358        int __user *clear_child_tid;            /* CLONE_CHILD_CLEARTID */
1359
1360        cputime_t utime, stime, utimescaled, stimescaled;
1361        cputime_t gtime;
1362#ifndef CONFIG_VIRT_CPU_ACCOUNTING
1363        cputime_t prev_utime, prev_stime;
1364#endif
1365        unsigned long nvcsw, nivcsw; /* context switch counts */
1366        struct timespec start_time;             /* monotonic time */
1367        struct timespec real_start_time;        /* boot based time */
1368/* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1369        unsigned long min_flt, maj_flt;
1370
1371        struct task_cputime cputime_expires;
1372        struct list_head cpu_timers[3];
1373
1374/* process credentials */
1375        const struct cred __rcu *real_cred; /* objective and real subjective task
1376                                         * credentials (COW) */
1377        const struct cred __rcu *cred;  /* effective (overridable) subjective task
1378                                         * credentials (COW) */
1379        struct cred *replacement_session_keyring; /* for KEYCTL_SESSION_TO_PARENT */
1380
1381        char comm[TASK_COMM_LEN]; /* executable name excluding path
1382                                     - access with [gs]et_task_comm (which lock
1383                                       it with task_lock())
1384                                     - initialized normally by setup_new_exec */
1385/* file system info */
1386        int link_count, total_link_count;
1387#ifdef CONFIG_SYSVIPC
1388/* ipc stuff */
1389        struct sysv_sem sysvsem;
1390#endif
1391#ifdef CONFIG_DETECT_HUNG_TASK
1392/* hung task detection */
1393        unsigned long last_switch_count;
1394#endif
1395/* CPU-specific state of this task */
1396        struct thread_struct thread;
1397/* filesystem information */
1398        struct fs_struct *fs;
1399/* open file information */
1400        struct files_struct *files;
1401/* namespaces */
1402        struct nsproxy *nsproxy;
1403/* signal handlers */
1404        struct signal_struct *signal;
1405        struct sighand_struct *sighand;
1406
1407        sigset_t blocked, real_blocked;
1408        sigset_t saved_sigmask; /* restored if set_restore_sigmask() was used */
1409        struct sigpending pending;
1410
1411        unsigned long sas_ss_sp;
1412        size_t sas_ss_size;
1413        int (*notifier)(void *priv);
1414        void *notifier_data;
1415        sigset_t *notifier_mask;
1416        struct audit_context *audit_context;
1417#ifdef CONFIG_AUDITSYSCALL
1418        uid_t loginuid;
1419        unsigned int sessionid;
1420#endif
1421        seccomp_t seccomp;
1422
1423/* Thread group tracking */
1424        u32 parent_exec_id;
1425        u32 self_exec_id;
1426/* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1427 * mempolicy */
1428        spinlock_t alloc_lock;
1429
1430#ifdef CONFIG_GENERIC_HARDIRQS
1431        /* IRQ handler threads */
1432        struct irqaction *irqaction;
1433#endif
1434
1435        /* Protection of the PI data structures: */
1436        raw_spinlock_t pi_lock;
1437
1438#ifdef CONFIG_RT_MUTEXES
1439        /* PI waiters blocked on a rt_mutex held by this task */
1440        struct plist_head pi_waiters;
1441        /* Deadlock detection and priority inheritance handling */
1442        struct rt_mutex_waiter *pi_blocked_on;
1443#endif
1444
1445#ifdef CONFIG_DEBUG_MUTEXES
1446        /* mutex deadlock detection */
1447        struct mutex_waiter *blocked_on;
1448#endif
1449#ifdef CONFIG_TRACE_IRQFLAGS
1450        unsigned int irq_events;
1451        unsigned long hardirq_enable_ip;
1452        unsigned long hardirq_disable_ip;
1453        unsigned int hardirq_enable_event;
1454        unsigned int hardirq_disable_event;
1455        int hardirqs_enabled;
1456        int hardirq_context;
1457        unsigned long softirq_disable_ip;
1458        unsigned long softirq_enable_ip;
1459        unsigned int softirq_disable_event;
1460        unsigned int softirq_enable_event;
1461        int softirqs_enabled;
1462        int softirq_context;
1463#endif
1464#ifdef CONFIG_LOCKDEP
1465# define MAX_LOCK_DEPTH 48UL
1466        u64 curr_chain_key;
1467        int lockdep_depth;
1468        unsigned int lockdep_recursion;
1469        struct held_lock held_locks[MAX_LOCK_DEPTH];
1470        gfp_t lockdep_reclaim_gfp;
1471#endif
1472
1473/* journalling filesystem info */
1474        void *journal_info;
1475
1476/* stacked block device info */
1477        struct bio_list *bio_list;
1478
1479#ifdef CONFIG_BLOCK
1480/* stack plugging */
1481        struct blk_plug *plug;
1482#endif
1483
1484/* VM state */
1485        struct reclaim_state *reclaim_state;
1486
1487        struct backing_dev_info *backing_dev_info;
1488
1489        struct io_context *io_context;
1490
1491        unsigned long ptrace_message;
1492        siginfo_t *last_siginfo; /* For ptrace use.  */
1493        struct task_io_accounting ioac;
1494#if defined(CONFIG_TASK_XACCT)
1495        u64 acct_rss_mem1;      /* accumulated rss usage */
1496        u64 acct_vm_mem1;       /* accumulated virtual memory usage */
1497        cputime_t acct_timexpd; /* stime + utime since last update */
1498#endif
1499#ifdef CONFIG_CPUSETS
1500        nodemask_t mems_allowed;        /* Protected by alloc_lock */
1501        int mems_allowed_change_disable;
1502        int cpuset_mem_spread_rotor;
1503        int cpuset_slab_spread_rotor;
1504#endif
1505#ifdef CONFIG_CGROUPS
1506        /* Control Group info protected by css_set_lock */
1507        struct css_set __rcu *cgroups;
1508        /* cg_list protected by css_set_lock and tsk->alloc_lock */
1509        struct list_head cg_list;
1510#endif
1511#ifdef CONFIG_FUTEX
1512        struct robust_list_head __user *robust_list;
1513#ifdef CONFIG_COMPAT
1514        struct compat_robust_list_head __user *compat_robust_list;
1515#endif
1516        struct list_head pi_state_list;
1517        struct futex_pi_state *pi_state_cache;
1518#endif
1519#ifdef CONFIG_PERF_EVENTS
1520        struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1521        struct mutex perf_event_mutex;
1522        struct list_head perf_event_list;
1523#endif
1524#ifdef CONFIG_NUMA
1525        struct mempolicy *mempolicy;    /* Protected by alloc_lock */
1526        short il_next;
1527        short pref_node_fork;
1528#endif
1529        struct rcu_head rcu;
1530
1531        /*
1532         * cache last used pipe for splice
1533         */
1534        struct pipe_inode_info *splice_pipe;
1535#ifdef  CONFIG_TASK_DELAY_ACCT
1536        struct task_delay_info *delays;
1537#endif
1538#ifdef CONFIG_FAULT_INJECTION
1539        int make_it_fail;
1540#endif
1541        /*
1542         * when (nr_dirtied >= nr_dirtied_pause), it's time to call
1543         * balance_dirty_pages() for some dirty throttling pause
1544         */
1545        int nr_dirtied;
1546        int nr_dirtied_pause;
1547        unsigned long dirty_paused_when; /* start of a write-and-pause period */
1548
1549#ifdef CONFIG_LATENCYTOP
1550        int latency_record_count;
1551        struct latency_record latency_record[LT_SAVECOUNT];
1552#endif
1553        /*
1554         * time slack values; these are used to round up poll() and
1555         * select() etc timeout values. These are in nanoseconds.
1556         */
1557        unsigned long timer_slack_ns;
1558        unsigned long default_timer_slack_ns;
1559
1560        struct list_head        *scm_work_list;
1561#ifdef CONFIG_FUNCTION_GRAPH_TRACER
1562        /* Index of current stored address in ret_stack */
1563        int curr_ret_stack;
1564        /* Stack of return addresses for return function tracing */
1565        struct ftrace_ret_stack *ret_stack;
1566        /* time stamp for last schedule */
1567        unsigned long long ftrace_timestamp;
1568        /*
1569         * Number of functions that haven't been traced
1570         * because of depth overrun.
1571         */
1572        atomic_t trace_overrun;
1573        /* Pause for the tracing */
1574        atomic_t tracing_graph_pause;
1575#endif
1576#ifdef CONFIG_TRACING
1577        /* state flags for use by tracers */
1578        unsigned long trace;
1579        /* bitmask and counter of trace recursion */
1580        unsigned long trace_recursion;
1581#endif /* CONFIG_TRACING */
1582#ifdef CONFIG_CGROUP_MEM_RES_CTLR /* memcg uses this to do batch job */
1583        struct memcg_batch_info {
1584                int do_batch;   /* incremented when batch uncharge started */
1585                struct mem_cgroup *memcg; /* target memcg of uncharge */
1586                unsigned long nr_pages; /* uncharged usage */
1587                unsigned long memsw_nr_pages; /* uncharged mem+swap usage */
1588        } memcg_batch;
1589#endif
1590#ifdef CONFIG_HAVE_HW_BREAKPOINT
1591        atomic_t ptrace_bp_refcnt;
1592#endif
1593};
1594
1595/* Future-safe accessor for struct task_struct's cpus_allowed. */
1596#define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
1597
1598/*
1599 * Priority of a process goes from 0..MAX_PRIO-1, valid RT
1600 * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
1601 * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority
1602 * values are inverted: lower p->prio value means higher priority.
1603 *
1604 * The MAX_USER_RT_PRIO value allows the actual maximum
1605 * RT priority to be separate from the value exported to
1606 * user-space.  This allows kernel threads to set their
1607 * priority to a value higher than any user task. Note:
1608 * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
1609 */
1610
1611#define MAX_USER_RT_PRIO        100
1612#define MAX_RT_PRIO             MAX_USER_RT_PRIO
1613
1614#define MAX_PRIO                (MAX_RT_PRIO + 40)
1615#define DEFAULT_PRIO            (MAX_RT_PRIO + 20)
1616
1617static inline int rt_prio(int prio)
1618{
1619        if (unlikely(prio < MAX_RT_PRIO))
1620                return 1;
1621        return 0;
1622}
1623
1624static inline int rt_task(struct task_struct *p)
1625{
1626        return rt_prio(p->prio);
1627}
1628
1629static inline struct pid *task_pid(struct task_struct *task)
1630{
1631        return task->pids[PIDTYPE_PID].pid;
1632}
1633
1634static inline struct pid *task_tgid(struct task_struct *task)
1635{
1636        return task->group_leader->pids[PIDTYPE_PID].pid;
1637}
1638
1639/*
1640 * Without tasklist or rcu lock it is not safe to dereference
1641 * the result of task_pgrp/task_session even if task == current,
1642 * we can race with another thread doing sys_setsid/sys_setpgid.
1643 */
1644static inline struct pid *task_pgrp(struct task_struct *task)
1645{
1646        return task->group_leader->pids[PIDTYPE_PGID].pid;
1647}
1648
1649static inline struct pid *task_session(struct task_struct *task)
1650{
1651        return task->group_leader->pids[PIDTYPE_SID].pid;
1652}
1653
1654struct pid_namespace;
1655
1656/*
1657 * the helpers to get the task's different pids as they are seen
1658 * from various namespaces
1659 *
1660 * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1661 * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1662 *                     current.
1663 * task_xid_nr_ns()  : id seen from the ns specified;
1664 *
1665 * set_task_vxid()   : assigns a virtual id to a task;
1666 *
1667 * see also pid_nr() etc in include/linux/pid.h
1668 */
1669pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
1670                        struct pid_namespace *ns);
1671
1672static inline pid_t task_pid_nr(struct task_struct *tsk)
1673{
1674        return tsk->pid;
1675}
1676
1677static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
1678                                        struct pid_namespace *ns)
1679{
1680        return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1681}
1682
1683static inline pid_t task_pid_vnr(struct task_struct *tsk)
1684{
1685        return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1686}
1687
1688
1689static inline pid_t task_tgid_nr(struct task_struct *tsk)
1690{
1691        return tsk->tgid;
1692}
1693
1694pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1695
1696static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1697{
1698        return pid_vnr(task_tgid(tsk));
1699}
1700
1701
1702static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
1703                                        struct pid_namespace *ns)
1704{
1705        return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1706}
1707
1708static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1709{
1710        return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1711}
1712
1713
1714static inline pid_t task_session_nr_ns(struct task_struct *tsk,
1715                                        struct pid_namespace *ns)
1716{
1717        return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1718}
1719
1720static inline pid_t task_session_vnr(struct task_struct *tsk)
1721{
1722        return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1723}
1724
1725/* obsolete, do not use */
1726static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1727{
1728        return task_pgrp_nr_ns(tsk, &init_pid_ns);
1729}
1730
1731/**
1732 * pid_alive - check that a task structure is not stale
1733 * @p: Task structure to be checked.
1734 *
1735 * Test if a process is not yet dead (at most zombie state)
1736 * If pid_alive fails, then pointers within the task structure
1737 * can be stale and must not be dereferenced.
1738 */
1739static inline int pid_alive(struct task_struct *p)
1740{
1741        return p->pids[PIDTYPE_PID].pid != NULL;
1742}
1743
1744/**
1745 * is_global_init - check if a task structure is init
1746 * @tsk: Task structure to be checked.
1747 *
1748 * Check if a task structure is the first user space task the kernel created.
1749 */
1750static inline int is_global_init(struct task_struct *tsk)
1751{
1752        return tsk->pid == 1;
1753}
1754
1755/*
1756 * is_container_init:
1757 * check whether in the task is init in its own pid namespace.
1758 */
1759extern int is_container_init(struct task_struct *tsk);
1760
1761extern struct pid *cad_pid;
1762
1763extern void free_task(struct task_struct *tsk);
1764#define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
1765
1766extern void __put_task_struct(struct task_struct *t);
1767
1768static inline void put_task_struct(struct task_struct *t)
1769{
1770        if (atomic_dec_and_test(&t->usage))
1771                __put_task_struct(t);
1772}
1773
1774extern void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st);
1775extern void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st);
1776
1777/*
1778 * Per process flags
1779 */
1780#define PF_EXITING      0x00000004      /* getting shut down */
1781#define PF_EXITPIDONE   0x00000008      /* pi exit done on shut down */
1782#define PF_VCPU         0x00000010      /* I'm a virtual CPU */
1783#define PF_WQ_WORKER    0x00000020      /* I'm a workqueue worker */
1784#define PF_FORKNOEXEC   0x00000040      /* forked but didn't exec */
1785#define PF_MCE_PROCESS  0x00000080      /* process policy on mce errors */
1786#define PF_SUPERPRIV    0x00000100      /* used super-user privileges */
1787#define PF_DUMPCORE     0x00000200      /* dumped core */
1788#define PF_SIGNALED     0x00000400      /* killed by a signal */
1789#define PF_MEMALLOC     0x00000800      /* Allocating memory */
1790#define PF_NPROC_EXCEEDED 0x00001000    /* set_user noticed that RLIMIT_NPROC was exceeded */
1791#define PF_USED_MATH    0x00002000      /* if unset the fpu must be initialized before use */
1792#define PF_NOFREEZE     0x00008000      /* this thread should not be frozen */
1793#define PF_FROZEN       0x00010000      /* frozen for system suspend */
1794#define PF_FSTRANS      0x00020000      /* inside a filesystem transaction */
1795#define PF_KSWAPD       0x00040000      /* I am kswapd */
1796#define PF_LESS_THROTTLE 0x00100000     /* Throttle me less: I clean memory */
1797#define PF_KTHREAD      0x00200000      /* I am a kernel thread */
1798#define PF_RANDOMIZE    0x00400000      /* randomize virtual address space */
1799#define PF_SWAPWRITE    0x00800000      /* Allowed to write to swap */
1800#define PF_SPREAD_PAGE  0x01000000      /* Spread page cache over cpuset */
1801#define PF_SPREAD_SLAB  0x02000000      /* Spread some slab caches over cpuset */
1802#define PF_THREAD_BOUND 0x04000000      /* Thread bound to specific cpu */
1803#define PF_MCE_EARLY    0x08000000      /* Early kill for mce process policy */
1804#define PF_MEMPOLICY    0x10000000      /* Non-default NUMA mempolicy */
1805#define PF_MUTEX_TESTER 0x20000000      /* Thread belongs to the rt mutex tester */
1806#define PF_FREEZER_SKIP 0x40000000      /* Freezer should not count it as freezable */
1807
1808/*
1809 * Only the _current_ task can read/write to tsk->flags, but other
1810 * tasks can access tsk->flags in readonly mode for example
1811 * with tsk_used_math (like during threaded core dumping).
1812 * There is however an exception to this rule during ptrace
1813 * or during fork: the ptracer task is allowed to write to the
1814 * child->flags of its traced child (same goes for fork, the parent
1815 * can write to the child->flags), because we're guaranteed the
1816 * child is not running and in turn not changing child->flags
1817 * at the same time the parent does it.
1818 */
1819#define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1820#define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1821#define clear_used_math() clear_stopped_child_used_math(current)
1822#define set_used_math() set_stopped_child_used_math(current)
1823#define conditional_stopped_child_used_math(condition, child) \
1824        do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1825#define conditional_used_math(condition) \
1826        conditional_stopped_child_used_math(condition, current)
1827#define copy_to_stopped_child_used_math(child) \
1828        do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1829/* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1830#define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1831#define used_math() tsk_used_math(current)
1832
1833/*
1834 * task->jobctl flags
1835 */
1836#define JOBCTL_STOP_SIGMASK     0xffff  /* signr of the last group stop */
1837
1838#define JOBCTL_STOP_DEQUEUED_BIT 16     /* stop signal dequeued */
1839#define JOBCTL_STOP_PENDING_BIT 17      /* task should stop for group stop */
1840#define JOBCTL_STOP_CONSUME_BIT 18      /* consume group stop count */
1841#define JOBCTL_TRAP_STOP_BIT    19      /* trap for STOP */
1842#define JOBCTL_TRAP_NOTIFY_BIT  20      /* trap for NOTIFY */
1843#define JOBCTL_TRAPPING_BIT     21      /* switching to TRACED */
1844#define JOBCTL_LISTENING_BIT    22      /* ptracer is listening for events */
1845
1846#define JOBCTL_STOP_DEQUEUED    (1 << JOBCTL_STOP_DEQUEUED_BIT)
1847#define JOBCTL_STOP_PENDING     (1 << JOBCTL_STOP_PENDING_BIT)
1848#define JOBCTL_STOP_CONSUME     (1 << JOBCTL_STOP_CONSUME_BIT)
1849#define JOBCTL_TRAP_STOP        (1 << JOBCTL_TRAP_STOP_BIT)
1850#define JOBCTL_TRAP_NOTIFY      (1 << JOBCTL_TRAP_NOTIFY_BIT)
1851#define JOBCTL_TRAPPING         (1 << JOBCTL_TRAPPING_BIT)
1852#define JOBCTL_LISTENING        (1 << JOBCTL_LISTENING_BIT)
1853
1854#define JOBCTL_TRAP_MASK        (JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
1855#define JOBCTL_PENDING_MASK     (JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)
1856
1857extern bool task_set_jobctl_pending(struct task_struct *task,
1858                                    unsigned int mask);
1859extern void task_clear_jobctl_trapping(struct task_struct *task);
1860extern void task_clear_jobctl_pending(struct task_struct *task,
1861                                      unsigned int mask);
1862
1863#ifdef CONFIG_PREEMPT_RCU
1864
1865#define RCU_READ_UNLOCK_BLOCKED (1 << 0) /* blocked while in RCU read-side. */
1866#define RCU_READ_UNLOCK_BOOSTED (1 << 1) /* boosted while in RCU read-side. */
1867#define RCU_READ_UNLOCK_NEED_QS (1 << 2) /* RCU core needs CPU response. */
1868
1869static inline void rcu_copy_process(struct task_struct *p)
1870{
1871        p->rcu_read_lock_nesting = 0;
1872        p->rcu_read_unlock_special = 0;
1873#ifdef CONFIG_TREE_PREEMPT_RCU
1874        p->rcu_blocked_node = NULL;
1875#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
1876#ifdef CONFIG_RCU_BOOST
1877        p->rcu_boost_mutex = NULL;
1878#endif /* #ifdef CONFIG_RCU_BOOST */
1879        INIT_LIST_HEAD(&p->rcu_node_entry);
1880}
1881
1882#else
1883
1884static inline void rcu_copy_process(struct task_struct *p)
1885{
1886}
1887
1888#endif
1889
1890#ifdef CONFIG_SMP
1891extern void do_set_cpus_allowed(struct task_struct *p,
1892                               const struct cpumask *new_mask);
1893
1894extern int set_cpus_allowed_ptr(struct task_struct *p,
1895                                const struct cpumask *new_mask);
1896#else
1897static inline void do_set_cpus_allowed(struct task_struct *p,
1898                                      const struct cpumask *new_mask)
1899{
1900}
1901static inline int set_cpus_allowed_ptr(struct task_struct *p,
1902                                       const struct cpumask *new_mask)
1903{
1904        if (!cpumask_test_cpu(0, new_mask))
1905                return -EINVAL;
1906        return 0;
1907}
1908#endif
1909
1910#ifndef CONFIG_CPUMASK_OFFSTACK
1911static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
1912{
1913        return set_cpus_allowed_ptr(p, &new_mask);
1914}
1915#endif
1916
1917/*
1918 * Do not use outside of architecture code which knows its limitations.
1919 *
1920 * sched_clock() has no promise of monotonicity or bounded drift between
1921 * CPUs, use (which you should not) requires disabling IRQs.
1922 *
1923 * Please use one of the three interfaces below.
1924 */
1925extern unsigned long long notrace sched_clock(void);
1926/*
1927 * See the comment in kernel/sched_clock.c
1928 */
1929extern u64 cpu_clock(int cpu);
1930extern u64 local_clock(void);
1931extern u64 sched_clock_cpu(int cpu);
1932
1933
1934extern void sched_clock_init(void);
1935
1936#ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
1937static inline void sched_clock_tick(void)
1938{
1939}
1940
1941static inline void sched_clock_idle_sleep_event(void)
1942{
1943}
1944
1945static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
1946{
1947}
1948#else
1949/*
1950 * Architectures can set this to 1 if they have specified
1951 * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
1952 * but then during bootup it turns out that sched_clock()
1953 * is reliable after all:
1954 */
1955extern int sched_clock_stable;
1956
1957extern void sched_clock_tick(void);
1958extern void sched_clock_idle_sleep_event(void);
1959extern void sched_clock_idle_wakeup_event(u64 delta_ns);
1960#endif
1961
1962#ifdef CONFIG_IRQ_TIME_ACCOUNTING
1963/*
1964 * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
1965 * The reason for this explicit opt-in is not to have perf penalty with
1966 * slow sched_clocks.
1967 */
1968extern void enable_sched_clock_irqtime(void);
1969extern void disable_sched_clock_irqtime(void);
1970#else
1971static inline void enable_sched_clock_irqtime(void) {}
1972static inline void disable_sched_clock_irqtime(void) {}
1973#endif
1974
1975extern unsigned long long
1976task_sched_runtime(struct task_struct *task);
1977
1978/* sched_exec is called by processes performing an exec */
1979#ifdef CONFIG_SMP
1980extern void sched_exec(void);
1981#else
1982#define sched_exec()   {}
1983#endif
1984
1985extern void sched_clock_idle_sleep_event(void);
1986extern void sched_clock_idle_wakeup_event(u64 delta_ns);
1987
1988#ifdef CONFIG_HOTPLUG_CPU
1989extern void idle_task_exit(void);
1990#else
1991static inline void idle_task_exit(void) {}
1992#endif
1993
1994#if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP)
1995extern void wake_up_idle_cpu(int cpu);
1996#else
1997static inline void wake_up_idle_cpu(int cpu) { }
1998#endif
1999
2000extern unsigned int sysctl_sched_latency;
2001extern unsigned int sysctl_sched_min_granularity;
2002extern unsigned int sysctl_sched_wakeup_granularity;
2003extern unsigned int sysctl_sched_child_runs_first;
2004
2005enum sched_tunable_scaling {
2006        SCHED_TUNABLESCALING_NONE,
2007        SCHED_TUNABLESCALING_LOG,
2008        SCHED_TUNABLESCALING_LINEAR,
2009        SCHED_TUNABLESCALING_END,
2010};
2011extern enum sched_tunable_scaling sysctl_sched_tunable_scaling;
2012
2013#ifdef CONFIG_SCHED_DEBUG
2014extern unsigned int sysctl_sched_migration_cost;
2015extern unsigned int sysctl_sched_nr_migrate;
2016extern unsigned int sysctl_sched_time_avg;
2017extern unsigned int sysctl_timer_migration;
2018extern unsigned int sysctl_sched_shares_window;
2019
2020int sched_proc_update_handler(struct ctl_table *table, int write,
2021                void __user *buffer, size_t *length,
2022                loff_t *ppos);
2023#endif
2024#ifdef CONFIG_SCHED_DEBUG
2025static inline unsigned int get_sysctl_timer_migration(void)
2026{
2027        return sysctl_timer_migration;
2028}
2029#else
2030static inline unsigned int get_sysctl_timer_migration(void)
2031{
2032        return 1;
2033}
2034#endif
2035extern unsigned int sysctl_sched_rt_period;
2036extern int sysctl_sched_rt_runtime;
2037
2038int sched_rt_handler(struct ctl_table *table, int write,
2039                void __user *buffer, size_t *lenp,
2040                loff_t *ppos);
2041
2042#ifdef CONFIG_SCHED_AUTOGROUP
2043extern unsigned int sysctl_sched_autogroup_enabled;
2044
2045extern void sched_autogroup_create_attach(struct task_struct *p);
2046extern void sched_autogroup_detach(struct task_struct *p);
2047extern void sched_autogroup_fork(struct signal_struct *sig);
2048extern void sched_autogroup_exit(struct signal_struct *sig);
2049#ifdef CONFIG_PROC_FS
2050extern void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m);
2051extern int proc_sched_autogroup_set_nice(struct task_struct *p, int *nice);
2052#endif
2053#else
2054static inline void sched_autogroup_create_attach(struct task_struct *p) { }
2055static inline void sched_autogroup_detach(struct task_struct *p) { }
2056static inline void sched_autogroup_fork(struct signal_struct *sig) { }
2057static inline void sched_autogroup_exit(struct signal_struct *sig) { }
2058#endif
2059
2060#ifdef CONFIG_CFS_BANDWIDTH
2061extern unsigned int sysctl_sched_cfs_bandwidth_slice;
2062#endif
2063
2064#ifdef CONFIG_RT_MUTEXES
2065extern int rt_mutex_getprio(struct task_struct *p);
2066extern void rt_mutex_setprio(struct task_struct *p, int prio);
2067extern void rt_mutex_adjust_pi(struct task_struct *p);
2068#else
2069static inline int rt_mutex_getprio(struct task_struct *p)
2070{
2071        return p->normal_prio;
2072}
2073# define rt_mutex_adjust_pi(p)          do { } while (0)
2074#endif
2075
2076extern bool yield_to(struct task_struct *p, bool preempt);
2077extern void set_user_nice(struct task_struct *p, long nice);
2078extern int task_prio(const struct task_struct *p);
2079extern int task_nice(const struct task_struct *p);
2080extern int can_nice(const struct task_struct *p, const int nice);
2081extern int task_curr(const struct task_struct *p);
2082extern int idle_cpu(int cpu);
2083extern int sched_setscheduler(struct task_struct *, int,
2084                              const struct sched_param *);
2085extern int sched_setscheduler_nocheck(struct task_struct *, int,
2086                                      const struct sched_param *);
2087extern struct task_struct *idle_task(int cpu);
2088/**
2089 * is_idle_task - is the specified task an idle task?
2090 * @p: the task in question.
2091 */
2092static inline bool is_idle_task(const struct task_struct *p)
2093{
2094        return p->pid == 0;
2095}
2096extern struct task_struct *curr_task(int cpu);
2097extern void set_curr_task(int cpu, struct task_struct *p);
2098
2099void yield(void);
2100
2101/*
2102 * The default (Linux) execution domain.
2103 */
2104extern struct exec_domain       default_exec_domain;
2105
2106union thread_union {
2107        struct thread_info thread_info;
2108        unsigned long stack[THREAD_SIZE/sizeof(long)];
2109};
2110
2111#ifndef __HAVE_ARCH_KSTACK_END
2112static inline int kstack_end(void *addr)
2113{
2114        /* Reliable end of stack detection:
2115         * Some APM bios versions misalign the stack
2116         */
2117        return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
2118}
2119#endif
2120
2121extern union thread_union init_thread_union;
2122extern struct task_struct init_task;
2123
2124extern struct   mm_struct init_mm;
2125
2126extern struct pid_namespace init_pid_ns;
2127
2128/*
2129 * find a task by one of its numerical ids
2130 *
2131 * find_task_by_pid_ns():
2132 *      finds a task by its pid in the specified namespace
2133 * find_task_by_vpid():
2134 *      finds a task by its virtual pid
2135 *
2136 * see also find_vpid() etc in include/linux/pid.h
2137 */
2138
2139extern struct task_struct *find_task_by_vpid(pid_t nr);
2140extern struct task_struct *find_task_by_pid_ns(pid_t nr,
2141                struct pid_namespace *ns);
2142
2143extern void __set_special_pids(struct pid *pid);
2144
2145/* per-UID process charging. */
2146extern struct user_struct * alloc_uid(struct user_namespace *, uid_t);
2147static inline struct user_struct *get_uid(struct user_struct *u)
2148{
2149        atomic_inc(&u->__count);
2150        return u;
2151}
2152extern void free_uid(struct user_struct *);
2153extern void release_uids(struct user_namespace *ns);
2154
2155#include <asm/current.h>
2156
2157extern void xtime_update(unsigned long ticks);
2158
2159extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2160extern int wake_up_process(struct task_struct *tsk);
2161extern void wake_up_new_task(struct task_struct *tsk);
2162#ifdef CONFIG_SMP
2163 extern void kick_process(struct task_struct *tsk);
2164#else
2165 static inline void kick_process(struct task_struct *tsk) { }
2166#endif
2167extern void sched_fork(struct task_struct *p);
2168extern void sched_dead(struct task_struct *p);
2169
2170extern void proc_caches_init(void);
2171extern void flush_signals(struct task_struct *);
2172extern void __flush_signals(struct task_struct *);
2173extern void ignore_signals(struct task_struct *);
2174extern void flush_signal_handlers(struct task_struct *, int force_default);
2175extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
2176
2177static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
2178{
2179        unsigned long flags;
2180        int ret;
2181
2182        spin_lock_irqsave(&tsk->sighand->siglock, flags);
2183        ret = dequeue_signal(tsk, mask, info);
2184        spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
2185
2186        return ret;
2187}
2188
2189extern void block_all_signals(int (*notifier)(void *priv), void *priv,
2190                              sigset_t *mask);
2191extern void unblock_all_signals(void);
2192extern void release_task(struct task_struct * p);
2193extern int send_sig_info(int, struct siginfo *, struct task_struct *);
2194extern int force_sigsegv(int, struct task_struct *);
2195extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2196extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
2197extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2198extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *,
2199                                const struct cred *, u32);
2200extern int kill_pgrp(struct pid *pid, int sig, int priv);
2201extern int kill_pid(struct pid *pid, int sig, int priv);
2202extern int kill_proc_info(int, struct siginfo *, pid_t);
2203extern __must_check bool do_notify_parent(struct task_struct *, int);
2204extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
2205extern void force_sig(int, struct task_struct *);
2206extern int send_sig(int, struct task_struct *, int);
2207extern int zap_other_threads(struct task_struct *p);
2208extern struct sigqueue *sigqueue_alloc(void);
2209extern void sigqueue_free(struct sigqueue *);
2210extern int send_sigqueue(struct sigqueue *,  struct task_struct *, int group);
2211extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
2212extern int do_sigaltstack(const stack_t __user *, stack_t __user *, unsigned long);
2213
2214static inline int kill_cad_pid(int sig, int priv)
2215{
2216        return kill_pid(cad_pid, sig, priv);
2217}
2218
2219/* These can be the second arg to send_sig_info/send_group_sig_info.  */
2220#define SEND_SIG_NOINFO ((struct siginfo *) 0)
2221#define SEND_SIG_PRIV   ((struct siginfo *) 1)
2222#define SEND_SIG_FORCED ((struct siginfo *) 2)
2223
2224/*
2225 * True if we are on the alternate signal stack.
2226 */
2227static inline int on_sig_stack(unsigned long sp)
2228{
2229#ifdef CONFIG_STACK_GROWSUP
2230        return sp >= current->sas_ss_sp &&
2231                sp - current->sas_ss_sp < current->sas_ss_size;
2232#else
2233        return sp > current->sas_ss_sp &&
2234                sp - current->sas_ss_sp <= current->sas_ss_size;
2235#endif
2236}
2237
2238static inline int sas_ss_flags(unsigned long sp)
2239{
2240        return (current->sas_ss_size == 0 ? SS_DISABLE
2241                : on_sig_stack(sp) ? SS_ONSTACK : 0);
2242}
2243
2244/*
2245 * Routines for handling mm_structs
2246 */
2247extern struct mm_struct * mm_alloc(void);
2248
2249/* mmdrop drops the mm and the page tables */
2250extern void __mmdrop(struct mm_struct *);
2251static inline void mmdrop(struct mm_struct * mm)
2252{
2253        if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2254                __mmdrop(mm);
2255}
2256
2257/* mmput gets rid of the mappings and all user-space */
2258extern void mmput(struct mm_struct *);
2259/* Grab a reference to a task's mm, if it is not already going away */
2260extern struct mm_struct *get_task_mm(struct task_struct *task);
2261/*
2262 * Grab a reference to a task's mm, if it is not already going away
2263 * and ptrace_may_access with the mode parameter passed to it
2264 * succeeds.
2265 */
2266extern struct mm_struct *mm_access(struct task_struct *task, unsigned int mode);
2267/* Remove the current tasks stale references to the old mm_struct */
2268extern void mm_release(struct task_struct *, struct mm_struct *);
2269/* Allocate a new mm structure and copy contents from tsk->mm */
2270extern struct mm_struct *dup_mm(struct task_struct *tsk);
2271
2272extern int copy_thread(unsigned long, unsigned long, unsigned long,
2273                        struct task_struct *, struct pt_regs *);
2274extern void flush_thread(void);
2275extern void exit_thread(void);
2276
2277extern void exit_files(struct task_struct *);
2278extern void __cleanup_sighand(struct sighand_struct *);
2279
2280extern void exit_itimers(struct signal_struct *);
2281extern void flush_itimer_signals(void);
2282
2283extern void do_group_exit(int);
2284
2285extern void daemonize(const char *, ...);
2286extern int allow_signal(int);
2287extern int disallow_signal(int);
2288
2289extern int do_execve(const char *,
2290                     const char __user * const __user *,
2291                     const char __user * const __user *, struct pt_regs *);
2292extern long do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *);
2293struct task_struct *fork_idle(int);
2294
2295extern void set_task_comm(struct task_struct *tsk, char *from);
2296extern char *get_task_comm(char *to, struct task_struct *tsk);
2297
2298#ifdef CONFIG_SMP
2299void scheduler_ipi(void);
2300extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
2301#else
2302static inline void scheduler_ipi(void) { }
2303static inline unsigned long wait_task_inactive(struct task_struct *p,
2304                                               long match_state)
2305{
2306        return 1;
2307}
2308#endif
2309
2310#define next_task(p) \
2311        list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
2312
2313#define for_each_process(p) \
2314        for (p = &init_task ; (p = next_task(p)) != &init_task ; )
2315
2316extern bool current_is_single_threaded(void);
2317
2318/*
2319 * Careful: do_each_thread/while_each_thread is a double loop so
2320 *          'break' will not work as expected - use goto instead.
2321 */
2322#define do_each_thread(g, t) \
2323        for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
2324
2325#define while_each_thread(g, t) \
2326        while ((t = next_thread(t)) != g)
2327
2328static inline int get_nr_threads(struct task_struct *tsk)
2329{
2330        return tsk->signal->nr_threads;
2331}
2332
2333static inline bool thread_group_leader(struct task_struct *p)
2334{
2335        return p->exit_signal >= 0;
2336}
2337
2338/* Do to the insanities of de_thread it is possible for a process
2339 * to have the pid of the thread group leader without actually being
2340 * the thread group leader.  For iteration through the pids in proc
2341 * all we care about is that we have a task with the appropriate
2342 * pid, we don't actually care if we have the right task.
2343 */
2344static inline int has_group_leader_pid(struct task_struct *p)
2345{
2346        return p->pid == p->tgid;
2347}
2348
2349static inline
2350int same_thread_group(struct task_struct *p1, struct task_struct *p2)
2351{
2352        return p1->tgid == p2->tgid;
2353}
2354
2355static inline struct task_struct *next_thread(const struct task_struct *p)
2356{
2357        return list_entry_rcu(p->thread_group.next,
2358                              struct task_struct, thread_group);
2359}
2360
2361static inline int thread_group_empty(struct task_struct *p)
2362{
2363        return list_empty(&p->thread_group);
2364}
2365
2366#define delay_group_leader(p) \
2367                (thread_group_leader(p) && !thread_group_empty(p))
2368
2369/*
2370 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
2371 * subscriptions and synchronises with wait4().  Also used in procfs.  Also
2372 * pins the final release of task.io_context.  Also protects ->cpuset and
2373 * ->cgroup.subsys[]. And ->vfork_done.
2374 *
2375 * Nests both inside and outside of read_lock(&tasklist_lock).
2376 * It must not be nested with write_lock_irq(&tasklist_lock),
2377 * neither inside nor outside.
2378 */
2379static inline void task_lock(struct task_struct *p)
2380{
2381        spin_lock(&p->alloc_lock);
2382}
2383
2384static inline void task_unlock(struct task_struct *p)
2385{
2386        spin_unlock(&p->alloc_lock);
2387}
2388
2389extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
2390                                                        unsigned long *flags);
2391
2392#define lock_task_sighand(tsk, flags)                                   \
2393({      struct sighand_struct *__ss;                                    \
2394        __cond_lock(&(tsk)->sighand->siglock,                           \
2395                    (__ss = __lock_task_sighand(tsk, flags)));          \
2396        __ss;                                                           \
2397})                                                                      \
2398
2399static inline void unlock_task_sighand(struct task_struct *tsk,
2400                                                unsigned long *flags)
2401{
2402        spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
2403}
2404
2405#ifdef CONFIG_CGROUPS
2406static inline void threadgroup_change_begin(struct task_struct *tsk)
2407{
2408        down_read(&tsk->signal->group_rwsem);
2409}
2410static inline void threadgroup_change_end(struct task_struct *tsk)
2411{
2412        up_read(&tsk->signal->group_rwsem);
2413}
2414
2415/**
2416 * threadgroup_lock - lock threadgroup
2417 * @tsk: member task of the threadgroup to lock
2418 *
2419 * Lock the threadgroup @tsk belongs to.  No new task is allowed to enter
2420 * and member tasks aren't allowed to exit (as indicated by PF_EXITING) or
2421 * perform exec.  This is useful for cases where the threadgroup needs to
2422 * stay stable across blockable operations.
2423 *
2424 * fork and exit paths explicitly call threadgroup_change_{begin|end}() for
2425 * synchronization.  While held, no new task will be added to threadgroup
2426 * and no existing live task will have its PF_EXITING set.
2427 *
2428 * During exec, a task goes and puts its thread group through unusual
2429 * changes.  After de-threading, exclusive access is assumed to resources
2430 * which are usually shared by tasks in the same group - e.g. sighand may
2431 * be replaced with a new one.  Also, the exec'ing task takes over group
2432 * leader role including its pid.  Exclude these changes while locked by
2433 * grabbing cred_guard_mutex which is used to synchronize exec path.
2434 */
2435static inline void threadgroup_lock(struct task_struct *tsk)
2436{
2437        /*
2438         * exec uses exit for de-threading nesting group_rwsem inside
2439         * cred_guard_mutex. Grab cred_guard_mutex first.
2440         */
2441        mutex_lock(&tsk->signal->cred_guard_mutex);
2442        down_write(&tsk->signal->group_rwsem);
2443}
2444
2445/**
2446 * threadgroup_unlock - unlock threadgroup
2447 * @tsk: member task of the threadgroup to unlock
2448 *
2449 * Reverse threadgroup_lock().
2450 */
2451static inline void threadgroup_unlock(struct task_struct *tsk)
2452{
2453        up_write(&tsk->signal->group_rwsem);
2454        mutex_unlock(&tsk->signal->cred_guard_mutex);
2455}
2456#else
2457static inline void threadgroup_change_begin(struct task_struct *tsk) {}
2458static inline void threadgroup_change_end(struct task_struct *tsk) {}
2459static inline void threadgroup_lock(struct task_struct *tsk) {}
2460static inline void threadgroup_unlock(struct task_struct *tsk) {}
2461#endif
2462
2463#ifndef __HAVE_THREAD_FUNCTIONS
2464
2465#define task_thread_info(task)  ((struct thread_info *)(task)->stack)
2466#define task_stack_page(task)   ((task)->stack)
2467
2468static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
2469{
2470        *task_thread_info(p) = *task_thread_info(org);
2471        task_thread_info(p)->task = p;
2472}
2473
2474static inline unsigned long *end_of_stack(struct task_struct *p)
2475{
2476        return (unsigned long *)(task_thread_info(p) + 1);
2477}
2478
2479#endif
2480
2481static inline int object_is_on_stack(void *obj)
2482{
2483        void *stack = task_stack_page(current);
2484
2485        return (obj >= stack) && (obj < (stack + THREAD_SIZE));
2486}
2487
2488extern void thread_info_cache_init(void);
2489
2490#ifdef CONFIG_DEBUG_STACK_USAGE
2491static inline unsigned long stack_not_used(struct task_struct *p)
2492{
2493        unsigned long *n = end_of_stack(p);
2494
2495        do {    /* Skip over canary */
2496                n++;
2497        } while (!*n);
2498
2499        return (unsigned long)n - (unsigned long)end_of_stack(p);
2500}
2501#endif
2502
2503/* set thread flags in other task's structures
2504 * - see asm/thread_info.h for TIF_xxxx flags available
2505 */
2506static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2507{
2508        set_ti_thread_flag(task_thread_info(tsk), flag);
2509}
2510
2511static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2512{
2513        clear_ti_thread_flag(task_thread_info(tsk), flag);
2514}
2515
2516static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2517{
2518        return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2519}
2520
2521static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2522{
2523        return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2524}
2525
2526static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2527{
2528        return test_ti_thread_flag(task_thread_info(tsk), flag);
2529}
2530
2531static inline void set_tsk_need_resched(struct task_struct *tsk)
2532{
2533        set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2534}
2535
2536static inline void clear_tsk_need_resched(struct task_struct *tsk)
2537{
2538        clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2539}
2540
2541static inline int test_tsk_need_resched(struct task_struct *tsk)
2542{
2543        return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2544}
2545
2546static inline int restart_syscall(void)
2547{
2548        set_tsk_thread_flag(current, TIF_SIGPENDING);
2549        return -ERESTARTNOINTR;
2550}
2551
2552static inline int signal_pending(struct task_struct *p)
2553{
2554        return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
2555}
2556
2557static inline int __fatal_signal_pending(struct task_struct *p)
2558{
2559        return unlikely(sigismember(&p->pending.signal, SIGKILL));
2560}
2561
2562static inline int fatal_signal_pending(struct task_struct *p)
2563{
2564        return signal_pending(p) && __fatal_signal_pending(p);
2565}
2566
2567static inline int signal_pending_state(long state, struct task_struct *p)
2568{
2569        if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
2570                return 0;
2571        if (!signal_pending(p))
2572                return 0;
2573
2574        return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
2575}
2576
2577static inline int need_resched(void)
2578{
2579        return unlikely(test_thread_flag(TIF_NEED_RESCHED));
2580}
2581
2582/*
2583 * cond_resched() and cond_resched_lock(): latency reduction via
2584 * explicit rescheduling in places that are safe. The return
2585 * value indicates whether a reschedule was done in fact.
2586 * cond_resched_lock() will drop the spinlock before scheduling,
2587 * cond_resched_softirq() will enable bhs before scheduling.
2588 */
2589extern int _cond_resched(void);
2590
2591#define cond_resched() ({                       \
2592        __might_sleep(__FILE__, __LINE__, 0);   \
2593        _cond_resched();                        \
2594})
2595
2596extern int __cond_resched_lock(spinlock_t *lock);
2597
2598#ifdef CONFIG_PREEMPT_COUNT
2599#define PREEMPT_LOCK_OFFSET     PREEMPT_OFFSET
2600#else
2601#define PREEMPT_LOCK_OFFSET     0
2602#endif
2603
2604#define cond_resched_lock(lock) ({                              \
2605        __might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET); \
2606        __cond_resched_lock(lock);                              \
2607})
2608
2609extern int __cond_resched_softirq(void);
2610
2611#define cond_resched_softirq() ({                                       \
2612        __might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET);      \
2613        __cond_resched_softirq();                                       \
2614})
2615
2616/*
2617 * Does a critical section need to be broken due to another
2618 * task waiting?: (technically does not depend on CONFIG_PREEMPT,
2619 * but a general need for low latency)
2620 */
2621static inline int spin_needbreak(spinlock_t *lock)
2622{
2623#ifdef CONFIG_PREEMPT
2624        return spin_is_contended(lock);
2625#else
2626        return 0;
2627#endif
2628}
2629
2630/*
2631 * Thread group CPU time accounting.
2632 */
2633void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
2634void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
2635
2636static inline void thread_group_cputime_init(struct signal_struct *sig)
2637{
2638        raw_spin_lock_init(&sig->cputimer.lock);
2639}
2640
2641/*
2642 * Reevaluate whether the task has signals pending delivery.
2643 * Wake the task if so.
2644 * This is required every time the blocked sigset_t changes.
2645 * callers must hold sighand->siglock.
2646 */
2647extern void recalc_sigpending_and_wake(struct task_struct *t);
2648extern void recalc_sigpending(void);
2649
2650extern void signal_wake_up(struct task_struct *t, int resume_stopped);
2651
2652/*
2653 * Wrappers for p->thread_info->cpu access. No-op on UP.
2654 */
2655#ifdef CONFIG_SMP
2656
2657static inline unsigned int task_cpu(const struct task_struct *p)
2658{
2659        return task_thread_info(p)->cpu;
2660}
2661
2662extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2663
2664#else
2665
2666static inline unsigned int task_cpu(const struct task_struct *p)
2667{
2668        return 0;
2669}
2670
2671static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2672{
2673}
2674
2675#endif /* CONFIG_SMP */
2676
2677extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2678extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2679
2680extern void normalize_rt_tasks(void);
2681
2682#ifdef CONFIG_CGROUP_SCHED
2683
2684extern struct task_group root_task_group;
2685
2686extern struct task_group *sched_create_group(struct task_group *parent);
2687extern void sched_destroy_group(struct task_group *tg);
2688extern void sched_move_task(struct task_struct *tsk);
2689#ifdef CONFIG_FAIR_GROUP_SCHED
2690extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
2691extern unsigned long sched_group_shares(struct task_group *tg);
2692#endif
2693#ifdef CONFIG_RT_GROUP_SCHED
2694extern int sched_group_set_rt_runtime(struct task_group *tg,
2695                                      long rt_runtime_us);
2696extern long sched_group_rt_runtime(struct task_group *tg);
2697extern int sched_group_set_rt_period(struct task_group *tg,
2698                                      long rt_period_us);
2699extern long sched_group_rt_period(struct task_group *tg);
2700extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk);
2701#endif
2702#endif
2703
2704extern int task_can_switch_user(struct user_struct *up,
2705                                        struct task_struct *tsk);
2706
2707#ifdef CONFIG_TASK_XACCT
2708static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2709{
2710        tsk->ioac.rchar += amt;
2711}
2712
2713static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2714{
2715        tsk->ioac.wchar += amt;
2716}
2717
2718static inline void inc_syscr(struct task_struct *tsk)
2719{
2720        tsk->ioac.syscr++;
2721}
2722
2723static inline void inc_syscw(struct task_struct *tsk)
2724{
2725        tsk->ioac.syscw++;
2726}
2727#else
2728static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2729{
2730}
2731
2732static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2733{
2734}
2735
2736static inline void inc_syscr(struct task_struct *tsk)
2737{
2738}
2739
2740static inline void inc_syscw(struct task_struct *tsk)
2741{
2742}
2743#endif
2744
2745#ifndef TASK_SIZE_OF
2746#define TASK_SIZE_OF(tsk)       TASK_SIZE
2747#endif
2748
2749#ifdef CONFIG_MM_OWNER
2750extern void mm_update_next_owner(struct mm_struct *mm);
2751extern void mm_init_owner(struct mm_struct *mm, struct task_struct *p);
2752#else
2753static inline void mm_update_next_owner(struct mm_struct *mm)
2754{
2755}
2756
2757static inline void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
2758{
2759}
2760#endif /* CONFIG_MM_OWNER */
2761
2762static inline unsigned long task_rlimit(const struct task_struct *tsk,
2763                unsigned int limit)
2764{
2765        return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_cur);
2766}
2767
2768static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
2769                unsigned int limit)
2770{
2771        return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_max);
2772}
2773
2774static inline unsigned long rlimit(unsigned int limit)
2775{
2776        return task_rlimit(current, limit);
2777}
2778
2779static inline unsigned long rlimit_max(unsigned int limit)
2780{
2781        return task_rlimit_max(current, limit);
2782}
2783
2784#endif /* __KERNEL__ */
2785
2786#endif
2787