linux/include/linux/sched.h
<<
>>
Prefs
   1#ifndef _LINUX_SCHED_H
   2#define _LINUX_SCHED_H
   3
   4#include <uapi/linux/sched.h>
   5
   6#include <linux/sched/prio.h>
   7
   8
   9struct sched_param {
  10        int sched_priority;
  11};
  12
  13#include <asm/param.h>  /* for HZ */
  14
  15#include <linux/capability.h>
  16#include <linux/threads.h>
  17#include <linux/kernel.h>
  18#include <linux/types.h>
  19#include <linux/timex.h>
  20#include <linux/jiffies.h>
  21#include <linux/plist.h>
  22#include <linux/rbtree.h>
  23#include <linux/thread_info.h>
  24#include <linux/cpumask.h>
  25#include <linux/errno.h>
  26#include <linux/nodemask.h>
  27#include <linux/mm_types.h>
  28#include <linux/preempt_mask.h>
  29
  30#include <asm/page.h>
  31#include <asm/ptrace.h>
  32#include <linux/cputime.h>
  33
  34#include <linux/smp.h>
  35#include <linux/sem.h>
  36#include <linux/signal.h>
  37#include <linux/compiler.h>
  38#include <linux/completion.h>
  39#include <linux/pid.h>
  40#include <linux/percpu.h>
  41#include <linux/topology.h>
  42#include <linux/proportions.h>
  43#include <linux/seccomp.h>
  44#include <linux/rcupdate.h>
  45#include <linux/rculist.h>
  46#include <linux/rtmutex.h>
  47
  48#include <linux/time.h>
  49#include <linux/param.h>
  50#include <linux/resource.h>
  51#include <linux/timer.h>
  52#include <linux/hrtimer.h>
  53#include <linux/task_io_accounting.h>
  54#include <linux/latencytop.h>
  55#include <linux/cred.h>
  56#include <linux/llist.h>
  57#include <linux/uidgid.h>
  58#include <linux/gfp.h>
  59
  60#include <asm/processor.h>
  61
  62#define SCHED_ATTR_SIZE_VER0    48      /* sizeof first published struct */
  63
  64/*
  65 * Extended scheduling parameters data structure.
  66 *
  67 * This is needed because the original struct sched_param can not be
  68 * altered without introducing ABI issues with legacy applications
  69 * (e.g., in sched_getparam()).
  70 *
  71 * However, the possibility of specifying more than just a priority for
  72 * the tasks may be useful for a wide variety of application fields, e.g.,
  73 * multimedia, streaming, automation and control, and many others.
  74 *
  75 * This variant (sched_attr) is meant at describing a so-called
  76 * sporadic time-constrained task. In such model a task is specified by:
  77 *  - the activation period or minimum instance inter-arrival time;
  78 *  - the maximum (or average, depending on the actual scheduling
  79 *    discipline) computation time of all instances, a.k.a. runtime;
  80 *  - the deadline (relative to the actual activation time) of each
  81 *    instance.
  82 * Very briefly, a periodic (sporadic) task asks for the execution of
  83 * some specific computation --which is typically called an instance--
  84 * (at most) every period. Moreover, each instance typically lasts no more
  85 * than the runtime and must be completed by time instant t equal to
  86 * the instance activation time + the deadline.
  87 *
  88 * This is reflected by the actual fields of the sched_attr structure:
  89 *
  90 *  @size               size of the structure, for fwd/bwd compat.
  91 *
  92 *  @sched_policy       task's scheduling policy
  93 *  @sched_flags        for customizing the scheduler behaviour
  94 *  @sched_nice         task's nice value      (SCHED_NORMAL/BATCH)
  95 *  @sched_priority     task's static priority (SCHED_FIFO/RR)
  96 *  @sched_deadline     representative of the task's deadline
  97 *  @sched_runtime      representative of the task's runtime
  98 *  @sched_period       representative of the task's period
  99 *
 100 * Given this task model, there are a multiplicity of scheduling algorithms
 101 * and policies, that can be used to ensure all the tasks will make their
 102 * timing constraints.
 103 *
 104 * As of now, the SCHED_DEADLINE policy (sched_dl scheduling class) is the
 105 * only user of this new interface. More information about the algorithm
 106 * available in the scheduling class file or in Documentation/.
 107 */
 108struct sched_attr {
 109        u32 size;
 110
 111        u32 sched_policy;
 112        u64 sched_flags;
 113
 114        /* SCHED_NORMAL, SCHED_BATCH */
 115        s32 sched_nice;
 116
 117        /* SCHED_FIFO, SCHED_RR */
 118        u32 sched_priority;
 119
 120        /* SCHED_DEADLINE */
 121        u64 sched_runtime;
 122        u64 sched_deadline;
 123        u64 sched_period;
 124};
 125
 126struct exec_domain;
 127struct futex_pi_state;
 128struct robust_list_head;
 129struct bio_list;
 130struct fs_struct;
 131struct perf_event_context;
 132struct blk_plug;
 133struct filename;
 134
 135#define VMACACHE_BITS 2
 136#define VMACACHE_SIZE (1U << VMACACHE_BITS)
 137#define VMACACHE_MASK (VMACACHE_SIZE - 1)
 138
 139/*
 140 * These are the constant used to fake the fixed-point load-average
 141 * counting. Some notes:
 142 *  - 11 bit fractions expand to 22 bits by the multiplies: this gives
 143 *    a load-average precision of 10 bits integer + 11 bits fractional
 144 *  - if you want to count load-averages more often, you need more
 145 *    precision, or rounding will get you. With 2-second counting freq,
 146 *    the EXP_n values would be 1981, 2034 and 2043 if still using only
 147 *    11 bit fractions.
 148 */
 149extern unsigned long avenrun[];         /* Load averages */
 150extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
 151
 152#define FSHIFT          11              /* nr of bits of precision */
 153#define FIXED_1         (1<<FSHIFT)     /* 1.0 as fixed-point */
 154#define LOAD_FREQ       (5*HZ+1)        /* 5 sec intervals */
 155#define EXP_1           1884            /* 1/exp(5sec/1min) as fixed-point */
 156#define EXP_5           2014            /* 1/exp(5sec/5min) */
 157#define EXP_15          2037            /* 1/exp(5sec/15min) */
 158
 159#define CALC_LOAD(load,exp,n) \
 160        load *= exp; \
 161        load += n*(FIXED_1-exp); \
 162        load >>= FSHIFT;
 163
 164extern unsigned long total_forks;
 165extern int nr_threads;
 166DECLARE_PER_CPU(unsigned long, process_counts);
 167extern int nr_processes(void);
 168extern unsigned long nr_running(void);
 169extern unsigned long nr_iowait(void);
 170extern unsigned long nr_iowait_cpu(int cpu);
 171extern unsigned long this_cpu_load(void);
 172
 173
 174extern void calc_global_load(unsigned long ticks);
 175extern void update_cpu_load_nohz(void);
 176
 177extern unsigned long get_parent_ip(unsigned long addr);
 178
 179extern void dump_cpu_task(int cpu);
 180
 181struct seq_file;
 182struct cfs_rq;
 183struct task_group;
 184#ifdef CONFIG_SCHED_DEBUG
 185extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
 186extern void proc_sched_set_task(struct task_struct *p);
 187extern void
 188print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
 189#endif
 190
 191/*
 192 * Task state bitmask. NOTE! These bits are also
 193 * encoded in fs/proc/array.c: get_task_state().
 194 *
 195 * We have two separate sets of flags: task->state
 196 * is about runnability, while task->exit_state are
 197 * about the task exiting. Confusing, but this way
 198 * modifying one set can't modify the other one by
 199 * mistake.
 200 */
 201#define TASK_RUNNING            0
 202#define TASK_INTERRUPTIBLE      1
 203#define TASK_UNINTERRUPTIBLE    2
 204#define __TASK_STOPPED          4
 205#define __TASK_TRACED           8
 206/* in tsk->exit_state */
 207#define EXIT_DEAD               16
 208#define EXIT_ZOMBIE             32
 209#define EXIT_TRACE              (EXIT_ZOMBIE | EXIT_DEAD)
 210/* in tsk->state again */
 211#define TASK_DEAD               64
 212#define TASK_WAKEKILL           128
 213#define TASK_WAKING             256
 214#define TASK_PARKED             512
 215#define TASK_STATE_MAX          1024
 216
 217#define TASK_STATE_TO_CHAR_STR "RSDTtXZxKWP"
 218
 219extern char ___assert_task_state[1 - 2*!!(
 220                sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
 221
 222/* Convenience macros for the sake of set_task_state */
 223#define TASK_KILLABLE           (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
 224#define TASK_STOPPED            (TASK_WAKEKILL | __TASK_STOPPED)
 225#define TASK_TRACED             (TASK_WAKEKILL | __TASK_TRACED)
 226
 227/* Convenience macros for the sake of wake_up */
 228#define TASK_NORMAL             (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
 229#define TASK_ALL                (TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
 230
 231/* get_task_state() */
 232#define TASK_REPORT             (TASK_RUNNING | TASK_INTERRUPTIBLE | \
 233                                 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
 234                                 __TASK_TRACED | EXIT_ZOMBIE | EXIT_DEAD)
 235
 236#define task_is_traced(task)    ((task->state & __TASK_TRACED) != 0)
 237#define task_is_stopped(task)   ((task->state & __TASK_STOPPED) != 0)
 238#define task_is_stopped_or_traced(task) \
 239                        ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
 240#define task_contributes_to_load(task)  \
 241                                ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
 242                                 (task->flags & PF_FROZEN) == 0)
 243
 244#define __set_task_state(tsk, state_value)              \
 245        do { (tsk)->state = (state_value); } while (0)
 246#define set_task_state(tsk, state_value)                \
 247        set_mb((tsk)->state, (state_value))
 248
 249/*
 250 * set_current_state() includes a barrier so that the write of current->state
 251 * is correctly serialised wrt the caller's subsequent test of whether to
 252 * actually sleep:
 253 *
 254 *      set_current_state(TASK_UNINTERRUPTIBLE);
 255 *      if (do_i_need_to_sleep())
 256 *              schedule();
 257 *
 258 * If the caller does not need such serialisation then use __set_current_state()
 259 */
 260#define __set_current_state(state_value)                        \
 261        do { current->state = (state_value); } while (0)
 262#define set_current_state(state_value)          \
 263        set_mb(current->state, (state_value))
 264
 265/* Task command name length */
 266#define TASK_COMM_LEN 16
 267
 268#include <linux/spinlock.h>
 269
 270/*
 271 * This serializes "schedule()" and also protects
 272 * the run-queue from deletions/modifications (but
 273 * _adding_ to the beginning of the run-queue has
 274 * a separate lock).
 275 */
 276extern rwlock_t tasklist_lock;
 277extern spinlock_t mmlist_lock;
 278
 279struct task_struct;
 280
 281#ifdef CONFIG_PROVE_RCU
 282extern int lockdep_tasklist_lock_is_held(void);
 283#endif /* #ifdef CONFIG_PROVE_RCU */
 284
 285extern void sched_init(void);
 286extern void sched_init_smp(void);
 287extern asmlinkage void schedule_tail(struct task_struct *prev);
 288extern void init_idle(struct task_struct *idle, int cpu);
 289extern void init_idle_bootup_task(struct task_struct *idle);
 290
 291extern int runqueue_is_locked(int cpu);
 292
 293#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
 294extern void nohz_balance_enter_idle(int cpu);
 295extern void set_cpu_sd_state_idle(void);
 296extern int get_nohz_timer_target(int pinned);
 297#else
 298static inline void nohz_balance_enter_idle(int cpu) { }
 299static inline void set_cpu_sd_state_idle(void) { }
 300static inline int get_nohz_timer_target(int pinned)
 301{
 302        return smp_processor_id();
 303}
 304#endif
 305
 306/*
 307 * Only dump TASK_* tasks. (0 for all tasks)
 308 */
 309extern void show_state_filter(unsigned long state_filter);
 310
 311static inline void show_state(void)
 312{
 313        show_state_filter(0);
 314}
 315
 316extern void show_regs(struct pt_regs *);
 317
 318/*
 319 * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
 320 * task), SP is the stack pointer of the first frame that should be shown in the back
 321 * trace (or NULL if the entire call-chain of the task should be shown).
 322 */
 323extern void show_stack(struct task_struct *task, unsigned long *sp);
 324
 325void io_schedule(void);
 326long io_schedule_timeout(long timeout);
 327
 328extern void cpu_init (void);
 329extern void trap_init(void);
 330extern void update_process_times(int user);
 331extern void scheduler_tick(void);
 332
 333extern void sched_show_task(struct task_struct *p);
 334
 335#ifdef CONFIG_LOCKUP_DETECTOR
 336extern void touch_softlockup_watchdog(void);
 337extern void touch_softlockup_watchdog_sync(void);
 338extern void touch_all_softlockup_watchdogs(void);
 339extern int proc_dowatchdog_thresh(struct ctl_table *table, int write,
 340                                  void __user *buffer,
 341                                  size_t *lenp, loff_t *ppos);
 342extern unsigned int  softlockup_panic;
 343void lockup_detector_init(void);
 344#else
 345static inline void touch_softlockup_watchdog(void)
 346{
 347}
 348static inline void touch_softlockup_watchdog_sync(void)
 349{
 350}
 351static inline void touch_all_softlockup_watchdogs(void)
 352{
 353}
 354static inline void lockup_detector_init(void)
 355{
 356}
 357#endif
 358
 359#ifdef CONFIG_DETECT_HUNG_TASK
 360void reset_hung_task_detector(void);
 361#else
 362static inline void reset_hung_task_detector(void)
 363{
 364}
 365#endif
 366
 367/* Attach to any functions which should be ignored in wchan output. */
 368#define __sched         __attribute__((__section__(".sched.text")))
 369
 370/* Linker adds these: start and end of __sched functions */
 371extern char __sched_text_start[], __sched_text_end[];
 372
 373/* Is this address in the __sched functions? */
 374extern int in_sched_functions(unsigned long addr);
 375
 376#define MAX_SCHEDULE_TIMEOUT    LONG_MAX
 377extern signed long schedule_timeout(signed long timeout);
 378extern signed long schedule_timeout_interruptible(signed long timeout);
 379extern signed long schedule_timeout_killable(signed long timeout);
 380extern signed long schedule_timeout_uninterruptible(signed long timeout);
 381asmlinkage void schedule(void);
 382extern void schedule_preempt_disabled(void);
 383
 384struct nsproxy;
 385struct user_namespace;
 386
 387#ifdef CONFIG_MMU
 388extern void arch_pick_mmap_layout(struct mm_struct *mm);
 389extern unsigned long
 390arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
 391                       unsigned long, unsigned long);
 392extern unsigned long
 393arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
 394                          unsigned long len, unsigned long pgoff,
 395                          unsigned long flags);
 396#else
 397static inline void arch_pick_mmap_layout(struct mm_struct *mm) {}
 398#endif
 399
 400#define SUID_DUMP_DISABLE       0       /* No setuid dumping */
 401#define SUID_DUMP_USER          1       /* Dump as user of process */
 402#define SUID_DUMP_ROOT          2       /* Dump as root */
 403
 404/* mm flags */
 405
 406/* for SUID_DUMP_* above */
 407#define MMF_DUMPABLE_BITS 2
 408#define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
 409
 410extern void set_dumpable(struct mm_struct *mm, int value);
 411/*
 412 * This returns the actual value of the suid_dumpable flag. For things
 413 * that are using this for checking for privilege transitions, it must
 414 * test against SUID_DUMP_USER rather than treating it as a boolean
 415 * value.
 416 */
 417static inline int __get_dumpable(unsigned long mm_flags)
 418{
 419        return mm_flags & MMF_DUMPABLE_MASK;
 420}
 421
 422static inline int get_dumpable(struct mm_struct *mm)
 423{
 424        return __get_dumpable(mm->flags);
 425}
 426
 427/* coredump filter bits */
 428#define MMF_DUMP_ANON_PRIVATE   2
 429#define MMF_DUMP_ANON_SHARED    3
 430#define MMF_DUMP_MAPPED_PRIVATE 4
 431#define MMF_DUMP_MAPPED_SHARED  5
 432#define MMF_DUMP_ELF_HEADERS    6
 433#define MMF_DUMP_HUGETLB_PRIVATE 7
 434#define MMF_DUMP_HUGETLB_SHARED  8
 435
 436#define MMF_DUMP_FILTER_SHIFT   MMF_DUMPABLE_BITS
 437#define MMF_DUMP_FILTER_BITS    7
 438#define MMF_DUMP_FILTER_MASK \
 439        (((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
 440#define MMF_DUMP_FILTER_DEFAULT \
 441        ((1 << MMF_DUMP_ANON_PRIVATE) | (1 << MMF_DUMP_ANON_SHARED) |\
 442         (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
 443
 444#ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
 445# define MMF_DUMP_MASK_DEFAULT_ELF      (1 << MMF_DUMP_ELF_HEADERS)
 446#else
 447# define MMF_DUMP_MASK_DEFAULT_ELF      0
 448#endif
 449                                        /* leave room for more dump flags */
 450#define MMF_VM_MERGEABLE        16      /* KSM may merge identical pages */
 451#define MMF_VM_HUGEPAGE         17      /* set when VM_HUGEPAGE is set on vma */
 452#define MMF_EXE_FILE_CHANGED    18      /* see prctl_set_mm_exe_file() */
 453
 454#define MMF_HAS_UPROBES         19      /* has uprobes */
 455#define MMF_RECALC_UPROBES      20      /* MMF_HAS_UPROBES can be wrong */
 456
 457#define MMF_INIT_MASK           (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
 458
 459struct sighand_struct {
 460        atomic_t                count;
 461        struct k_sigaction      action[_NSIG];
 462        spinlock_t              siglock;
 463        wait_queue_head_t       signalfd_wqh;
 464};
 465
 466struct pacct_struct {
 467        int                     ac_flag;
 468        long                    ac_exitcode;
 469        unsigned long           ac_mem;
 470        cputime_t               ac_utime, ac_stime;
 471        unsigned long           ac_minflt, ac_majflt;
 472};
 473
 474struct cpu_itimer {
 475        cputime_t expires;
 476        cputime_t incr;
 477        u32 error;
 478        u32 incr_error;
 479};
 480
 481/**
 482 * struct cputime - snaphsot of system and user cputime
 483 * @utime: time spent in user mode
 484 * @stime: time spent in system mode
 485 *
 486 * Gathers a generic snapshot of user and system time.
 487 */
 488struct cputime {
 489        cputime_t utime;
 490        cputime_t stime;
 491};
 492
 493/**
 494 * struct task_cputime - collected CPU time counts
 495 * @utime:              time spent in user mode, in &cputime_t units
 496 * @stime:              time spent in kernel mode, in &cputime_t units
 497 * @sum_exec_runtime:   total time spent on the CPU, in nanoseconds
 498 *
 499 * This is an extension of struct cputime that includes the total runtime
 500 * spent by the task from the scheduler point of view.
 501 *
 502 * As a result, this structure groups together three kinds of CPU time
 503 * that are tracked for threads and thread groups.  Most things considering
 504 * CPU time want to group these counts together and treat all three
 505 * of them in parallel.
 506 */
 507struct task_cputime {
 508        cputime_t utime;
 509        cputime_t stime;
 510        unsigned long long sum_exec_runtime;
 511};
 512/* Alternate field names when used to cache expirations. */
 513#define prof_exp        stime
 514#define virt_exp        utime
 515#define sched_exp       sum_exec_runtime
 516
 517#define INIT_CPUTIME    \
 518        (struct task_cputime) {                                 \
 519                .utime = 0,                                     \
 520                .stime = 0,                                     \
 521                .sum_exec_runtime = 0,                          \
 522        }
 523
 524#ifdef CONFIG_PREEMPT_COUNT
 525#define PREEMPT_DISABLED        (1 + PREEMPT_ENABLED)
 526#else
 527#define PREEMPT_DISABLED        PREEMPT_ENABLED
 528#endif
 529
 530/*
 531 * Disable preemption until the scheduler is running.
 532 * Reset by start_kernel()->sched_init()->init_idle().
 533 *
 534 * We include PREEMPT_ACTIVE to avoid cond_resched() from working
 535 * before the scheduler is active -- see should_resched().
 536 */
 537#define INIT_PREEMPT_COUNT      (PREEMPT_DISABLED + PREEMPT_ACTIVE)
 538
 539/**
 540 * struct thread_group_cputimer - thread group interval timer counts
 541 * @cputime:            thread group interval timers.
 542 * @running:            non-zero when there are timers running and
 543 *                      @cputime receives updates.
 544 * @lock:               lock for fields in this struct.
 545 *
 546 * This structure contains the version of task_cputime, above, that is
 547 * used for thread group CPU timer calculations.
 548 */
 549struct thread_group_cputimer {
 550        struct task_cputime cputime;
 551        int running;
 552        raw_spinlock_t lock;
 553};
 554
 555#include <linux/rwsem.h>
 556struct autogroup;
 557
 558/*
 559 * NOTE! "signal_struct" does not have its own
 560 * locking, because a shared signal_struct always
 561 * implies a shared sighand_struct, so locking
 562 * sighand_struct is always a proper superset of
 563 * the locking of signal_struct.
 564 */
 565struct signal_struct {
 566        atomic_t                sigcnt;
 567        atomic_t                live;
 568        int                     nr_threads;
 569        struct list_head        thread_head;
 570
 571        wait_queue_head_t       wait_chldexit;  /* for wait4() */
 572
 573        /* current thread group signal load-balancing target: */
 574        struct task_struct      *curr_target;
 575
 576        /* shared signal handling: */
 577        struct sigpending       shared_pending;
 578
 579        /* thread group exit support */
 580        int                     group_exit_code;
 581        /* overloaded:
 582         * - notify group_exit_task when ->count is equal to notify_count
 583         * - everyone except group_exit_task is stopped during signal delivery
 584         *   of fatal signals, group_exit_task processes the signal.
 585         */
 586        int                     notify_count;
 587        struct task_struct      *group_exit_task;
 588
 589        /* thread group stop support, overloads group_exit_code too */
 590        int                     group_stop_count;
 591        unsigned int            flags; /* see SIGNAL_* flags below */
 592
 593        /*
 594         * PR_SET_CHILD_SUBREAPER marks a process, like a service
 595         * manager, to re-parent orphan (double-forking) child processes
 596         * to this process instead of 'init'. The service manager is
 597         * able to receive SIGCHLD signals and is able to investigate
 598         * the process until it calls wait(). All children of this
 599         * process will inherit a flag if they should look for a
 600         * child_subreaper process at exit.
 601         */
 602        unsigned int            is_child_subreaper:1;
 603        unsigned int            has_child_subreaper:1;
 604
 605        /* POSIX.1b Interval Timers */
 606        int                     posix_timer_id;
 607        struct list_head        posix_timers;
 608
 609        /* ITIMER_REAL timer for the process */
 610        struct hrtimer real_timer;
 611        struct pid *leader_pid;
 612        ktime_t it_real_incr;
 613
 614        /*
 615         * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
 616         * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
 617         * values are defined to 0 and 1 respectively
 618         */
 619        struct cpu_itimer it[2];
 620
 621        /*
 622         * Thread group totals for process CPU timers.
 623         * See thread_group_cputimer(), et al, for details.
 624         */
 625        struct thread_group_cputimer cputimer;
 626
 627        /* Earliest-expiration cache. */
 628        struct task_cputime cputime_expires;
 629
 630        struct list_head cpu_timers[3];
 631
 632        struct pid *tty_old_pgrp;
 633
 634        /* boolean value for session group leader */
 635        int leader;
 636
 637        struct tty_struct *tty; /* NULL if no tty */
 638
 639#ifdef CONFIG_SCHED_AUTOGROUP
 640        struct autogroup *autogroup;
 641#endif
 642        /*
 643         * Cumulative resource counters for dead threads in the group,
 644         * and for reaped dead child processes forked by this group.
 645         * Live threads maintain their own counters and add to these
 646         * in __exit_signal, except for the group leader.
 647         */
 648        cputime_t utime, stime, cutime, cstime;
 649        cputime_t gtime;
 650        cputime_t cgtime;
 651#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 652        struct cputime prev_cputime;
 653#endif
 654        unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
 655        unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
 656        unsigned long inblock, oublock, cinblock, coublock;
 657        unsigned long maxrss, cmaxrss;
 658        struct task_io_accounting ioac;
 659
 660        /*
 661         * Cumulative ns of schedule CPU time fo dead threads in the
 662         * group, not including a zombie group leader, (This only differs
 663         * from jiffies_to_ns(utime + stime) if sched_clock uses something
 664         * other than jiffies.)
 665         */
 666        unsigned long long sum_sched_runtime;
 667
 668        /*
 669         * We don't bother to synchronize most readers of this at all,
 670         * because there is no reader checking a limit that actually needs
 671         * to get both rlim_cur and rlim_max atomically, and either one
 672         * alone is a single word that can safely be read normally.
 673         * getrlimit/setrlimit use task_lock(current->group_leader) to
 674         * protect this instead of the siglock, because they really
 675         * have no need to disable irqs.
 676         */
 677        struct rlimit rlim[RLIM_NLIMITS];
 678
 679#ifdef CONFIG_BSD_PROCESS_ACCT
 680        struct pacct_struct pacct;      /* per-process accounting information */
 681#endif
 682#ifdef CONFIG_TASKSTATS
 683        struct taskstats *stats;
 684#endif
 685#ifdef CONFIG_AUDIT
 686        unsigned audit_tty;
 687        unsigned audit_tty_log_passwd;
 688        struct tty_audit_buf *tty_audit_buf;
 689#endif
 690#ifdef CONFIG_CGROUPS
 691        /*
 692         * group_rwsem prevents new tasks from entering the threadgroup and
 693         * member tasks from exiting,a more specifically, setting of
 694         * PF_EXITING.  fork and exit paths are protected with this rwsem
 695         * using threadgroup_change_begin/end().  Users which require
 696         * threadgroup to remain stable should use threadgroup_[un]lock()
 697         * which also takes care of exec path.  Currently, cgroup is the
 698         * only user.
 699         */
 700        struct rw_semaphore group_rwsem;
 701#endif
 702
 703        oom_flags_t oom_flags;
 704        short oom_score_adj;            /* OOM kill score adjustment */
 705        short oom_score_adj_min;        /* OOM kill score adjustment min value.
 706                                         * Only settable by CAP_SYS_RESOURCE. */
 707
 708        struct mutex cred_guard_mutex;  /* guard against foreign influences on
 709                                         * credential calculations
 710                                         * (notably. ptrace) */
 711};
 712
 713/*
 714 * Bits in flags field of signal_struct.
 715 */
 716#define SIGNAL_STOP_STOPPED     0x00000001 /* job control stop in effect */
 717#define SIGNAL_STOP_CONTINUED   0x00000002 /* SIGCONT since WCONTINUED reap */
 718#define SIGNAL_GROUP_EXIT       0x00000004 /* group exit in progress */
 719#define SIGNAL_GROUP_COREDUMP   0x00000008 /* coredump in progress */
 720/*
 721 * Pending notifications to parent.
 722 */
 723#define SIGNAL_CLD_STOPPED      0x00000010
 724#define SIGNAL_CLD_CONTINUED    0x00000020
 725#define SIGNAL_CLD_MASK         (SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
 726
 727#define SIGNAL_UNKILLABLE       0x00000040 /* for init: ignore fatal signals */
 728
 729/* If true, all threads except ->group_exit_task have pending SIGKILL */
 730static inline int signal_group_exit(const struct signal_struct *sig)
 731{
 732        return  (sig->flags & SIGNAL_GROUP_EXIT) ||
 733                (sig->group_exit_task != NULL);
 734}
 735
 736/*
 737 * Some day this will be a full-fledged user tracking system..
 738 */
 739struct user_struct {
 740        atomic_t __count;       /* reference count */
 741        atomic_t processes;     /* How many processes does this user have? */
 742        atomic_t sigpending;    /* How many pending signals does this user have? */
 743#ifdef CONFIG_INOTIFY_USER
 744        atomic_t inotify_watches; /* How many inotify watches does this user have? */
 745        atomic_t inotify_devs;  /* How many inotify devs does this user have opened? */
 746#endif
 747#ifdef CONFIG_FANOTIFY
 748        atomic_t fanotify_listeners;
 749#endif
 750#ifdef CONFIG_EPOLL
 751        atomic_long_t epoll_watches; /* The number of file descriptors currently watched */
 752#endif
 753#ifdef CONFIG_POSIX_MQUEUE
 754        /* protected by mq_lock */
 755        unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */
 756#endif
 757        unsigned long locked_shm; /* How many pages of mlocked shm ? */
 758
 759#ifdef CONFIG_KEYS
 760        struct key *uid_keyring;        /* UID specific keyring */
 761        struct key *session_keyring;    /* UID's default session keyring */
 762#endif
 763
 764        /* Hash table maintenance information */
 765        struct hlist_node uidhash_node;
 766        kuid_t uid;
 767
 768#ifdef CONFIG_PERF_EVENTS
 769        atomic_long_t locked_vm;
 770#endif
 771};
 772
 773extern int uids_sysfs_init(void);
 774
 775extern struct user_struct *find_user(kuid_t);
 776
 777extern struct user_struct root_user;
 778#define INIT_USER (&root_user)
 779
 780
 781struct backing_dev_info;
 782struct reclaim_state;
 783
 784#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
 785struct sched_info {
 786        /* cumulative counters */
 787        unsigned long pcount;         /* # of times run on this cpu */
 788        unsigned long long run_delay; /* time spent waiting on a runqueue */
 789
 790        /* timestamps */
 791        unsigned long long last_arrival,/* when we last ran on a cpu */
 792                           last_queued; /* when we were last queued to run */
 793};
 794#endif /* defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) */
 795
 796#ifdef CONFIG_TASK_DELAY_ACCT
 797struct task_delay_info {
 798        spinlock_t      lock;
 799        unsigned int    flags;  /* Private per-task flags */
 800
 801        /* For each stat XXX, add following, aligned appropriately
 802         *
 803         * struct timespec XXX_start, XXX_end;
 804         * u64 XXX_delay;
 805         * u32 XXX_count;
 806         *
 807         * Atomicity of updates to XXX_delay, XXX_count protected by
 808         * single lock above (split into XXX_lock if contention is an issue).
 809         */
 810
 811        /*
 812         * XXX_count is incremented on every XXX operation, the delay
 813         * associated with the operation is added to XXX_delay.
 814         * XXX_delay contains the accumulated delay time in nanoseconds.
 815         */
 816        struct timespec blkio_start, blkio_end; /* Shared by blkio, swapin */
 817        u64 blkio_delay;        /* wait for sync block io completion */
 818        u64 swapin_delay;       /* wait for swapin block io completion */
 819        u32 blkio_count;        /* total count of the number of sync block */
 820                                /* io operations performed */
 821        u32 swapin_count;       /* total count of the number of swapin block */
 822                                /* io operations performed */
 823
 824        struct timespec freepages_start, freepages_end;
 825        u64 freepages_delay;    /* wait for memory reclaim */
 826        u32 freepages_count;    /* total count of memory reclaim */
 827};
 828#endif  /* CONFIG_TASK_DELAY_ACCT */
 829
 830static inline int sched_info_on(void)
 831{
 832#ifdef CONFIG_SCHEDSTATS
 833        return 1;
 834#elif defined(CONFIG_TASK_DELAY_ACCT)
 835        extern int delayacct_on;
 836        return delayacct_on;
 837#else
 838        return 0;
 839#endif
 840}
 841
 842enum cpu_idle_type {
 843        CPU_IDLE,
 844        CPU_NOT_IDLE,
 845        CPU_NEWLY_IDLE,
 846        CPU_MAX_IDLE_TYPES
 847};
 848
 849/*
 850 * Increase resolution of cpu_capacity calculations
 851 */
 852#define SCHED_CAPACITY_SHIFT    10
 853#define SCHED_CAPACITY_SCALE    (1L << SCHED_CAPACITY_SHIFT)
 854
 855/*
 856 * sched-domains (multiprocessor balancing) declarations:
 857 */
 858#ifdef CONFIG_SMP
 859#define SD_LOAD_BALANCE         0x0001  /* Do load balancing on this domain. */
 860#define SD_BALANCE_NEWIDLE      0x0002  /* Balance when about to become idle */
 861#define SD_BALANCE_EXEC         0x0004  /* Balance on exec */
 862#define SD_BALANCE_FORK         0x0008  /* Balance on fork, clone */
 863#define SD_BALANCE_WAKE         0x0010  /* Balance on wakeup */
 864#define SD_WAKE_AFFINE          0x0020  /* Wake task to waking CPU */
 865#define SD_SHARE_CPUCAPACITY    0x0080  /* Domain members share cpu power */
 866#define SD_SHARE_POWERDOMAIN    0x0100  /* Domain members share power domain */
 867#define SD_SHARE_PKG_RESOURCES  0x0200  /* Domain members share cpu pkg resources */
 868#define SD_SERIALIZE            0x0400  /* Only a single load balancing instance */
 869#define SD_ASYM_PACKING         0x0800  /* Place busy groups earlier in the domain */
 870#define SD_PREFER_SIBLING       0x1000  /* Prefer to place tasks in a sibling domain */
 871#define SD_OVERLAP              0x2000  /* sched_domains of this level overlap */
 872#define SD_NUMA                 0x4000  /* cross-node balancing */
 873
 874#ifdef CONFIG_SCHED_SMT
 875static inline int cpu_smt_flags(void)
 876{
 877        return SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
 878}
 879#endif
 880
 881#ifdef CONFIG_SCHED_MC
 882static inline int cpu_core_flags(void)
 883{
 884        return SD_SHARE_PKG_RESOURCES;
 885}
 886#endif
 887
 888#ifdef CONFIG_NUMA
 889static inline int cpu_numa_flags(void)
 890{
 891        return SD_NUMA;
 892}
 893#endif
 894
 895struct sched_domain_attr {
 896        int relax_domain_level;
 897};
 898
 899#define SD_ATTR_INIT    (struct sched_domain_attr) {    \
 900        .relax_domain_level = -1,                       \
 901}
 902
 903extern int sched_domain_level_max;
 904
 905struct sched_group;
 906
 907struct sched_domain {
 908        /* These fields must be setup */
 909        struct sched_domain *parent;    /* top domain must be null terminated */
 910        struct sched_domain *child;     /* bottom domain must be null terminated */
 911        struct sched_group *groups;     /* the balancing groups of the domain */
 912        unsigned long min_interval;     /* Minimum balance interval ms */
 913        unsigned long max_interval;     /* Maximum balance interval ms */
 914        unsigned int busy_factor;       /* less balancing by factor if busy */
 915        unsigned int imbalance_pct;     /* No balance until over watermark */
 916        unsigned int cache_nice_tries;  /* Leave cache hot tasks for # tries */
 917        unsigned int busy_idx;
 918        unsigned int idle_idx;
 919        unsigned int newidle_idx;
 920        unsigned int wake_idx;
 921        unsigned int forkexec_idx;
 922        unsigned int smt_gain;
 923
 924        int nohz_idle;                  /* NOHZ IDLE status */
 925        int flags;                      /* See SD_* */
 926        int level;
 927
 928        /* Runtime fields. */
 929        unsigned long last_balance;     /* init to jiffies. units in jiffies */
 930        unsigned int balance_interval;  /* initialise to 1. units in ms. */
 931        unsigned int nr_balance_failed; /* initialise to 0 */
 932
 933        /* idle_balance() stats */
 934        u64 max_newidle_lb_cost;
 935        unsigned long next_decay_max_lb_cost;
 936
 937#ifdef CONFIG_SCHEDSTATS
 938        /* load_balance() stats */
 939        unsigned int lb_count[CPU_MAX_IDLE_TYPES];
 940        unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
 941        unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
 942        unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
 943        unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
 944        unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
 945        unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
 946        unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
 947
 948        /* Active load balancing */
 949        unsigned int alb_count;
 950        unsigned int alb_failed;
 951        unsigned int alb_pushed;
 952
 953        /* SD_BALANCE_EXEC stats */
 954        unsigned int sbe_count;
 955        unsigned int sbe_balanced;
 956        unsigned int sbe_pushed;
 957
 958        /* SD_BALANCE_FORK stats */
 959        unsigned int sbf_count;
 960        unsigned int sbf_balanced;
 961        unsigned int sbf_pushed;
 962
 963        /* try_to_wake_up() stats */
 964        unsigned int ttwu_wake_remote;
 965        unsigned int ttwu_move_affine;
 966        unsigned int ttwu_move_balance;
 967#endif
 968#ifdef CONFIG_SCHED_DEBUG
 969        char *name;
 970#endif
 971        union {
 972                void *private;          /* used during construction */
 973                struct rcu_head rcu;    /* used during destruction */
 974        };
 975
 976        unsigned int span_weight;
 977        /*
 978         * Span of all CPUs in this domain.
 979         *
 980         * NOTE: this field is variable length. (Allocated dynamically
 981         * by attaching extra space to the end of the structure,
 982         * depending on how many CPUs the kernel has booted up with)
 983         */
 984        unsigned long span[0];
 985};
 986
 987static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
 988{
 989        return to_cpumask(sd->span);
 990}
 991
 992extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
 993                                    struct sched_domain_attr *dattr_new);
 994
 995/* Allocate an array of sched domains, for partition_sched_domains(). */
 996cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
 997void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
 998
 999bool cpus_share_cache(int this_cpu, int that_cpu);
1000
1001typedef const struct cpumask *(*sched_domain_mask_f)(int cpu);
1002typedef int (*sched_domain_flags_f)(void);
1003
1004#define SDTL_OVERLAP    0x01
1005
1006struct sd_data {
1007        struct sched_domain **__percpu sd;
1008        struct sched_group **__percpu sg;
1009        struct sched_group_capacity **__percpu sgc;
1010};
1011
1012struct sched_domain_topology_level {
1013        sched_domain_mask_f mask;
1014        sched_domain_flags_f sd_flags;
1015        int                 flags;
1016        int                 numa_level;
1017        struct sd_data      data;
1018#ifdef CONFIG_SCHED_DEBUG
1019        char                *name;
1020#endif
1021};
1022
1023extern struct sched_domain_topology_level *sched_domain_topology;
1024
1025extern void set_sched_topology(struct sched_domain_topology_level *tl);
1026
1027#ifdef CONFIG_SCHED_DEBUG
1028# define SD_INIT_NAME(type)             .name = #type
1029#else
1030# define SD_INIT_NAME(type)
1031#endif
1032
1033#else /* CONFIG_SMP */
1034
1035struct sched_domain_attr;
1036
1037static inline void
1038partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1039                        struct sched_domain_attr *dattr_new)
1040{
1041}
1042
1043static inline bool cpus_share_cache(int this_cpu, int that_cpu)
1044{
1045        return true;
1046}
1047
1048#endif  /* !CONFIG_SMP */
1049
1050
1051struct io_context;                      /* See blkdev.h */
1052
1053
1054#ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
1055extern void prefetch_stack(struct task_struct *t);
1056#else
1057static inline void prefetch_stack(struct task_struct *t) { }
1058#endif
1059
1060struct audit_context;           /* See audit.c */
1061struct mempolicy;
1062struct pipe_inode_info;
1063struct uts_namespace;
1064
1065struct load_weight {
1066        unsigned long weight;
1067        u32 inv_weight;
1068};
1069
1070struct sched_avg {
1071        /*
1072         * These sums represent an infinite geometric series and so are bound
1073         * above by 1024/(1-y).  Thus we only need a u32 to store them for all
1074         * choices of y < 1-2^(-32)*1024.
1075         */
1076        u32 runnable_avg_sum, runnable_avg_period;
1077        u64 last_runnable_update;
1078        s64 decay_count;
1079        unsigned long load_avg_contrib;
1080};
1081
1082#ifdef CONFIG_SCHEDSTATS
1083struct sched_statistics {
1084        u64                     wait_start;
1085        u64                     wait_max;
1086        u64                     wait_count;
1087        u64                     wait_sum;
1088        u64                     iowait_count;
1089        u64                     iowait_sum;
1090
1091        u64                     sleep_start;
1092        u64                     sleep_max;
1093        s64                     sum_sleep_runtime;
1094
1095        u64                     block_start;
1096        u64                     block_max;
1097        u64                     exec_max;
1098        u64                     slice_max;
1099
1100        u64                     nr_migrations_cold;
1101        u64                     nr_failed_migrations_affine;
1102        u64                     nr_failed_migrations_running;
1103        u64                     nr_failed_migrations_hot;
1104        u64                     nr_forced_migrations;
1105
1106        u64                     nr_wakeups;
1107        u64                     nr_wakeups_sync;
1108        u64                     nr_wakeups_migrate;
1109        u64                     nr_wakeups_local;
1110        u64                     nr_wakeups_remote;
1111        u64                     nr_wakeups_affine;
1112        u64                     nr_wakeups_affine_attempts;
1113        u64                     nr_wakeups_passive;
1114        u64                     nr_wakeups_idle;
1115};
1116#endif
1117
1118struct sched_entity {
1119        struct load_weight      load;           /* for load-balancing */
1120        struct rb_node          run_node;
1121        struct list_head        group_node;
1122        unsigned int            on_rq;
1123
1124        u64                     exec_start;
1125        u64                     sum_exec_runtime;
1126        u64                     vruntime;
1127        u64                     prev_sum_exec_runtime;
1128
1129        u64                     nr_migrations;
1130
1131#ifdef CONFIG_SCHEDSTATS
1132        struct sched_statistics statistics;
1133#endif
1134
1135#ifdef CONFIG_FAIR_GROUP_SCHED
1136        int                     depth;
1137        struct sched_entity     *parent;
1138        /* rq on which this entity is (to be) queued: */
1139        struct cfs_rq           *cfs_rq;
1140        /* rq "owned" by this entity/group: */
1141        struct cfs_rq           *my_q;
1142#endif
1143
1144#ifdef CONFIG_SMP
1145        /* Per-entity load-tracking */
1146        struct sched_avg        avg;
1147#endif
1148};
1149
1150struct sched_rt_entity {
1151        struct list_head run_list;
1152        unsigned long timeout;
1153        unsigned long watchdog_stamp;
1154        unsigned int time_slice;
1155
1156        struct sched_rt_entity *back;
1157#ifdef CONFIG_RT_GROUP_SCHED
1158        struct sched_rt_entity  *parent;
1159        /* rq on which this entity is (to be) queued: */
1160        struct rt_rq            *rt_rq;
1161        /* rq "owned" by this entity/group: */
1162        struct rt_rq            *my_q;
1163#endif
1164};
1165
1166struct sched_dl_entity {
1167        struct rb_node  rb_node;
1168
1169        /*
1170         * Original scheduling parameters. Copied here from sched_attr
1171         * during sched_setattr(), they will remain the same until
1172         * the next sched_setattr().
1173         */
1174        u64 dl_runtime;         /* maximum runtime for each instance    */
1175        u64 dl_deadline;        /* relative deadline of each instance   */
1176        u64 dl_period;          /* separation of two instances (period) */
1177        u64 dl_bw;              /* dl_runtime / dl_deadline             */
1178
1179        /*
1180         * Actual scheduling parameters. Initialized with the values above,
1181         * they are continously updated during task execution. Note that
1182         * the remaining runtime could be < 0 in case we are in overrun.
1183         */
1184        s64 runtime;            /* remaining runtime for this instance  */
1185        u64 deadline;           /* absolute deadline for this instance  */
1186        unsigned int flags;     /* specifying the scheduler behaviour   */
1187
1188        /*
1189         * Some bool flags:
1190         *
1191         * @dl_throttled tells if we exhausted the runtime. If so, the
1192         * task has to wait for a replenishment to be performed at the
1193         * next firing of dl_timer.
1194         *
1195         * @dl_new tells if a new instance arrived. If so we must
1196         * start executing it with full runtime and reset its absolute
1197         * deadline;
1198         *
1199         * @dl_boosted tells if we are boosted due to DI. If so we are
1200         * outside bandwidth enforcement mechanism (but only until we
1201         * exit the critical section);
1202         *
1203         * @dl_yielded tells if task gave up the cpu before consuming
1204         * all its available runtime during the last job.
1205         */
1206        int dl_throttled, dl_new, dl_boosted, dl_yielded;
1207
1208        /*
1209         * Bandwidth enforcement timer. Each -deadline task has its
1210         * own bandwidth to be enforced, thus we need one timer per task.
1211         */
1212        struct hrtimer dl_timer;
1213};
1214
1215struct rcu_node;
1216
1217enum perf_event_task_context {
1218        perf_invalid_context = -1,
1219        perf_hw_context = 0,
1220        perf_sw_context,
1221        perf_nr_task_contexts,
1222};
1223
1224struct task_struct {
1225        volatile long state;    /* -1 unrunnable, 0 runnable, >0 stopped */
1226        void *stack;
1227        atomic_t usage;
1228        unsigned int flags;     /* per process flags, defined below */
1229        unsigned int ptrace;
1230
1231#ifdef CONFIG_SMP
1232        struct llist_node wake_entry;
1233        int on_cpu;
1234        struct task_struct *last_wakee;
1235        unsigned long wakee_flips;
1236        unsigned long wakee_flip_decay_ts;
1237
1238        int wake_cpu;
1239#endif
1240        int on_rq;
1241
1242        int prio, static_prio, normal_prio;
1243        unsigned int rt_priority;
1244        const struct sched_class *sched_class;
1245        struct sched_entity se;
1246        struct sched_rt_entity rt;
1247#ifdef CONFIG_CGROUP_SCHED
1248        struct task_group *sched_task_group;
1249#endif
1250        struct sched_dl_entity dl;
1251
1252#ifdef CONFIG_PREEMPT_NOTIFIERS
1253        /* list of struct preempt_notifier: */
1254        struct hlist_head preempt_notifiers;
1255#endif
1256
1257#ifdef CONFIG_BLK_DEV_IO_TRACE
1258        unsigned int btrace_seq;
1259#endif
1260
1261        unsigned int policy;
1262        int nr_cpus_allowed;
1263        cpumask_t cpus_allowed;
1264
1265#ifdef CONFIG_PREEMPT_RCU
1266        int rcu_read_lock_nesting;
1267        char rcu_read_unlock_special;
1268        struct list_head rcu_node_entry;
1269#endif /* #ifdef CONFIG_PREEMPT_RCU */
1270#ifdef CONFIG_TREE_PREEMPT_RCU
1271        struct rcu_node *rcu_blocked_node;
1272#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
1273#ifdef CONFIG_RCU_BOOST
1274        struct rt_mutex *rcu_boost_mutex;
1275#endif /* #ifdef CONFIG_RCU_BOOST */
1276
1277#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
1278        struct sched_info sched_info;
1279#endif
1280
1281        struct list_head tasks;
1282#ifdef CONFIG_SMP
1283        struct plist_node pushable_tasks;
1284        struct rb_node pushable_dl_tasks;
1285#endif
1286
1287        struct mm_struct *mm, *active_mm;
1288#ifdef CONFIG_COMPAT_BRK
1289        unsigned brk_randomized:1;
1290#endif
1291        /* per-thread vma caching */
1292        u32 vmacache_seqnum;
1293        struct vm_area_struct *vmacache[VMACACHE_SIZE];
1294#if defined(SPLIT_RSS_COUNTING)
1295        struct task_rss_stat    rss_stat;
1296#endif
1297/* task state */
1298        int exit_state;
1299        int exit_code, exit_signal;
1300        int pdeath_signal;  /*  The signal sent when the parent dies  */
1301        unsigned int jobctl;    /* JOBCTL_*, siglock protected */
1302
1303        /* Used for emulating ABI behavior of previous Linux versions */
1304        unsigned int personality;
1305
1306        unsigned in_execve:1;   /* Tell the LSMs that the process is doing an
1307                                 * execve */
1308        unsigned in_iowait:1;
1309
1310        /* task may not gain privileges */
1311        unsigned no_new_privs:1;
1312
1313        /* Revert to default priority/policy when forking */
1314        unsigned sched_reset_on_fork:1;
1315        unsigned sched_contributes_to_load:1;
1316
1317        pid_t pid;
1318        pid_t tgid;
1319
1320#ifdef CONFIG_CC_STACKPROTECTOR
1321        /* Canary value for the -fstack-protector gcc feature */
1322        unsigned long stack_canary;
1323#endif
1324        /*
1325         * pointers to (original) parent process, youngest child, younger sibling,
1326         * older sibling, respectively.  (p->father can be replaced with
1327         * p->real_parent->pid)
1328         */
1329        struct task_struct __rcu *real_parent; /* real parent process */
1330        struct task_struct __rcu *parent; /* recipient of SIGCHLD, wait4() reports */
1331        /*
1332         * children/sibling forms the list of my natural children
1333         */
1334        struct list_head children;      /* list of my children */
1335        struct list_head sibling;       /* linkage in my parent's children list */
1336        struct task_struct *group_leader;       /* threadgroup leader */
1337
1338        /*
1339         * ptraced is the list of tasks this task is using ptrace on.
1340         * This includes both natural children and PTRACE_ATTACH targets.
1341         * p->ptrace_entry is p's link on the p->parent->ptraced list.
1342         */
1343        struct list_head ptraced;
1344        struct list_head ptrace_entry;
1345
1346        /* PID/PID hash table linkage. */
1347        struct pid_link pids[PIDTYPE_MAX];
1348        struct list_head thread_group;
1349        struct list_head thread_node;
1350
1351        struct completion *vfork_done;          /* for vfork() */
1352        int __user *set_child_tid;              /* CLONE_CHILD_SETTID */
1353        int __user *clear_child_tid;            /* CLONE_CHILD_CLEARTID */
1354
1355        cputime_t utime, stime, utimescaled, stimescaled;
1356        cputime_t gtime;
1357#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
1358        struct cputime prev_cputime;
1359#endif
1360#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1361        seqlock_t vtime_seqlock;
1362        unsigned long long vtime_snap;
1363        enum {
1364                VTIME_SLEEPING = 0,
1365                VTIME_USER,
1366                VTIME_SYS,
1367        } vtime_snap_whence;
1368#endif
1369        unsigned long nvcsw, nivcsw; /* context switch counts */
1370        struct timespec start_time;             /* monotonic time */
1371        struct timespec real_start_time;        /* boot based time */
1372/* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1373        unsigned long min_flt, maj_flt;
1374
1375        struct task_cputime cputime_expires;
1376        struct list_head cpu_timers[3];
1377
1378/* process credentials */
1379        const struct cred __rcu *real_cred; /* objective and real subjective task
1380                                         * credentials (COW) */
1381        const struct cred __rcu *cred;  /* effective (overridable) subjective task
1382                                         * credentials (COW) */
1383        char comm[TASK_COMM_LEN]; /* executable name excluding path
1384                                     - access with [gs]et_task_comm (which lock
1385                                       it with task_lock())
1386                                     - initialized normally by setup_new_exec */
1387/* file system info */
1388        int link_count, total_link_count;
1389#ifdef CONFIG_SYSVIPC
1390/* ipc stuff */
1391        struct sysv_sem sysvsem;
1392#endif
1393#ifdef CONFIG_DETECT_HUNG_TASK
1394/* hung task detection */
1395        unsigned long last_switch_count;
1396#endif
1397/* CPU-specific state of this task */
1398        struct thread_struct thread;
1399/* filesystem information */
1400        struct fs_struct *fs;
1401/* open file information */
1402        struct files_struct *files;
1403/* namespaces */
1404        struct nsproxy *nsproxy;
1405/* signal handlers */
1406        struct signal_struct *signal;
1407        struct sighand_struct *sighand;
1408
1409        sigset_t blocked, real_blocked;
1410        sigset_t saved_sigmask; /* restored if set_restore_sigmask() was used */
1411        struct sigpending pending;
1412
1413        unsigned long sas_ss_sp;
1414        size_t sas_ss_size;
1415        int (*notifier)(void *priv);
1416        void *notifier_data;
1417        sigset_t *notifier_mask;
1418        struct callback_head *task_works;
1419
1420        struct audit_context *audit_context;
1421#ifdef CONFIG_AUDITSYSCALL
1422        kuid_t loginuid;
1423        unsigned int sessionid;
1424#endif
1425        struct seccomp seccomp;
1426
1427/* Thread group tracking */
1428        u32 parent_exec_id;
1429        u32 self_exec_id;
1430/* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1431 * mempolicy */
1432        spinlock_t alloc_lock;
1433
1434        /* Protection of the PI data structures: */
1435        raw_spinlock_t pi_lock;
1436
1437#ifdef CONFIG_RT_MUTEXES
1438        /* PI waiters blocked on a rt_mutex held by this task */
1439        struct rb_root pi_waiters;
1440        struct rb_node *pi_waiters_leftmost;
1441        /* Deadlock detection and priority inheritance handling */
1442        struct rt_mutex_waiter *pi_blocked_on;
1443        /* Top pi_waiters task */
1444        struct task_struct *pi_top_task;
1445#endif
1446
1447#ifdef CONFIG_DEBUG_MUTEXES
1448        /* mutex deadlock detection */
1449        struct mutex_waiter *blocked_on;
1450#endif
1451#ifdef CONFIG_TRACE_IRQFLAGS
1452        unsigned int irq_events;
1453        unsigned long hardirq_enable_ip;
1454        unsigned long hardirq_disable_ip;
1455        unsigned int hardirq_enable_event;
1456        unsigned int hardirq_disable_event;
1457        int hardirqs_enabled;
1458        int hardirq_context;
1459        unsigned long softirq_disable_ip;
1460        unsigned long softirq_enable_ip;
1461        unsigned int softirq_disable_event;
1462        unsigned int softirq_enable_event;
1463        int softirqs_enabled;
1464        int softirq_context;
1465#endif
1466#ifdef CONFIG_LOCKDEP
1467# define MAX_LOCK_DEPTH 48UL
1468        u64 curr_chain_key;
1469        int lockdep_depth;
1470        unsigned int lockdep_recursion;
1471        struct held_lock held_locks[MAX_LOCK_DEPTH];
1472        gfp_t lockdep_reclaim_gfp;
1473#endif
1474
1475/* journalling filesystem info */
1476        void *journal_info;
1477
1478/* stacked block device info */
1479        struct bio_list *bio_list;
1480
1481#ifdef CONFIG_BLOCK
1482/* stack plugging */
1483        struct blk_plug *plug;
1484#endif
1485
1486/* VM state */
1487        struct reclaim_state *reclaim_state;
1488
1489        struct backing_dev_info *backing_dev_info;
1490
1491        struct io_context *io_context;
1492
1493        unsigned long ptrace_message;
1494        siginfo_t *last_siginfo; /* For ptrace use.  */
1495        struct task_io_accounting ioac;
1496#if defined(CONFIG_TASK_XACCT)
1497        u64 acct_rss_mem1;      /* accumulated rss usage */
1498        u64 acct_vm_mem1;       /* accumulated virtual memory usage */
1499        cputime_t acct_timexpd; /* stime + utime since last update */
1500#endif
1501#ifdef CONFIG_CPUSETS
1502        nodemask_t mems_allowed;        /* Protected by alloc_lock */
1503        seqcount_t mems_allowed_seq;    /* Seqence no to catch updates */
1504        int cpuset_mem_spread_rotor;
1505        int cpuset_slab_spread_rotor;
1506#endif
1507#ifdef CONFIG_CGROUPS
1508        /* Control Group info protected by css_set_lock */
1509        struct css_set __rcu *cgroups;
1510        /* cg_list protected by css_set_lock and tsk->alloc_lock */
1511        struct list_head cg_list;
1512#endif
1513#ifdef CONFIG_FUTEX
1514        struct robust_list_head __user *robust_list;
1515#ifdef CONFIG_COMPAT
1516        struct compat_robust_list_head __user *compat_robust_list;
1517#endif
1518        struct list_head pi_state_list;
1519        struct futex_pi_state *pi_state_cache;
1520#endif
1521#ifdef CONFIG_PERF_EVENTS
1522        struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1523        struct mutex perf_event_mutex;
1524        struct list_head perf_event_list;
1525#endif
1526#ifdef CONFIG_DEBUG_PREEMPT
1527        unsigned long preempt_disable_ip;
1528#endif
1529#ifdef CONFIG_NUMA
1530        struct mempolicy *mempolicy;    /* Protected by alloc_lock */
1531        short il_next;
1532        short pref_node_fork;
1533#endif
1534#ifdef CONFIG_NUMA_BALANCING
1535        int numa_scan_seq;
1536        unsigned int numa_scan_period;
1537        unsigned int numa_scan_period_max;
1538        int numa_preferred_nid;
1539        unsigned long numa_migrate_retry;
1540        u64 node_stamp;                 /* migration stamp  */
1541        u64 last_task_numa_placement;
1542        u64 last_sum_exec_runtime;
1543        struct callback_head numa_work;
1544
1545        struct list_head numa_entry;
1546        struct numa_group *numa_group;
1547
1548        /*
1549         * Exponential decaying average of faults on a per-node basis.
1550         * Scheduling placement decisions are made based on the these counts.
1551         * The values remain static for the duration of a PTE scan
1552         */
1553        unsigned long *numa_faults_memory;
1554        unsigned long total_numa_faults;
1555
1556        /*
1557         * numa_faults_buffer records faults per node during the current
1558         * scan window. When the scan completes, the counts in
1559         * numa_faults_memory decay and these values are copied.
1560         */
1561        unsigned long *numa_faults_buffer_memory;
1562
1563        /*
1564         * Track the nodes the process was running on when a NUMA hinting
1565         * fault was incurred.
1566         */
1567        unsigned long *numa_faults_cpu;
1568        unsigned long *numa_faults_buffer_cpu;
1569
1570        /*
1571         * numa_faults_locality tracks if faults recorded during the last
1572         * scan window were remote/local. The task scan period is adapted
1573         * based on the locality of the faults with different weights
1574         * depending on whether they were shared or private faults
1575         */
1576        unsigned long numa_faults_locality[2];
1577
1578        unsigned long numa_pages_migrated;
1579#endif /* CONFIG_NUMA_BALANCING */
1580
1581        struct rcu_head rcu;
1582
1583        /*
1584         * cache last used pipe for splice
1585         */
1586        struct pipe_inode_info *splice_pipe;
1587
1588        struct page_frag task_frag;
1589
1590#ifdef  CONFIG_TASK_DELAY_ACCT
1591        struct task_delay_info *delays;
1592#endif
1593#ifdef CONFIG_FAULT_INJECTION
1594        int make_it_fail;
1595#endif
1596        /*
1597         * when (nr_dirtied >= nr_dirtied_pause), it's time to call
1598         * balance_dirty_pages() for some dirty throttling pause
1599         */
1600        int nr_dirtied;
1601        int nr_dirtied_pause;
1602        unsigned long dirty_paused_when; /* start of a write-and-pause period */
1603
1604#ifdef CONFIG_LATENCYTOP
1605        int latency_record_count;
1606        struct latency_record latency_record[LT_SAVECOUNT];
1607#endif
1608        /*
1609         * time slack values; these are used to round up poll() and
1610         * select() etc timeout values. These are in nanoseconds.
1611         */
1612        unsigned long timer_slack_ns;
1613        unsigned long default_timer_slack_ns;
1614
1615#ifdef CONFIG_FUNCTION_GRAPH_TRACER
1616        /* Index of current stored address in ret_stack */
1617        int curr_ret_stack;
1618        /* Stack of return addresses for return function tracing */
1619        struct ftrace_ret_stack *ret_stack;
1620        /* time stamp for last schedule */
1621        unsigned long long ftrace_timestamp;
1622        /*
1623         * Number of functions that haven't been traced
1624         * because of depth overrun.
1625         */
1626        atomic_t trace_overrun;
1627        /* Pause for the tracing */
1628        atomic_t tracing_graph_pause;
1629#endif
1630#ifdef CONFIG_TRACING
1631        /* state flags for use by tracers */
1632        unsigned long trace;
1633        /* bitmask and counter of trace recursion */
1634        unsigned long trace_recursion;
1635#endif /* CONFIG_TRACING */
1636#ifdef CONFIG_MEMCG /* memcg uses this to do batch job */
1637        struct memcg_batch_info {
1638                int do_batch;   /* incremented when batch uncharge started */
1639                struct mem_cgroup *memcg; /* target memcg of uncharge */
1640                unsigned long nr_pages; /* uncharged usage */
1641                unsigned long memsw_nr_pages; /* uncharged mem+swap usage */
1642        } memcg_batch;
1643        unsigned int memcg_kmem_skip_account;
1644        struct memcg_oom_info {
1645                struct mem_cgroup *memcg;
1646                gfp_t gfp_mask;
1647                int order;
1648                unsigned int may_oom:1;
1649        } memcg_oom;
1650#endif
1651#ifdef CONFIG_UPROBES
1652        struct uprobe_task *utask;
1653#endif
1654#if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1655        unsigned int    sequential_io;
1656        unsigned int    sequential_io_avg;
1657#endif
1658};
1659
1660/* Future-safe accessor for struct task_struct's cpus_allowed. */
1661#define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
1662
1663#define TNF_MIGRATED    0x01
1664#define TNF_NO_GROUP    0x02
1665#define TNF_SHARED      0x04
1666#define TNF_FAULT_LOCAL 0x08
1667
1668#ifdef CONFIG_NUMA_BALANCING
1669extern void task_numa_fault(int last_node, int node, int pages, int flags);
1670extern pid_t task_numa_group_id(struct task_struct *p);
1671extern void set_numabalancing_state(bool enabled);
1672extern void task_numa_free(struct task_struct *p);
1673extern bool should_numa_migrate_memory(struct task_struct *p, struct page *page,
1674                                        int src_nid, int dst_cpu);
1675#else
1676static inline void task_numa_fault(int last_node, int node, int pages,
1677                                   int flags)
1678{
1679}
1680static inline pid_t task_numa_group_id(struct task_struct *p)
1681{
1682        return 0;
1683}
1684static inline void set_numabalancing_state(bool enabled)
1685{
1686}
1687static inline void task_numa_free(struct task_struct *p)
1688{
1689}
1690static inline bool should_numa_migrate_memory(struct task_struct *p,
1691                                struct page *page, int src_nid, int dst_cpu)
1692{
1693        return true;
1694}
1695#endif
1696
1697static inline struct pid *task_pid(struct task_struct *task)
1698{
1699        return task->pids[PIDTYPE_PID].pid;
1700}
1701
1702static inline struct pid *task_tgid(struct task_struct *task)
1703{
1704        return task->group_leader->pids[PIDTYPE_PID].pid;
1705}
1706
1707/*
1708 * Without tasklist or rcu lock it is not safe to dereference
1709 * the result of task_pgrp/task_session even if task == current,
1710 * we can race with another thread doing sys_setsid/sys_setpgid.
1711 */
1712static inline struct pid *task_pgrp(struct task_struct *task)
1713{
1714        return task->group_leader->pids[PIDTYPE_PGID].pid;
1715}
1716
1717static inline struct pid *task_session(struct task_struct *task)
1718{
1719        return task->group_leader->pids[PIDTYPE_SID].pid;
1720}
1721
1722struct pid_namespace;
1723
1724/*
1725 * the helpers to get the task's different pids as they are seen
1726 * from various namespaces
1727 *
1728 * task_xid_nr()     : global id, i.e. the id seen from the init namespace;
1729 * task_xid_vnr()    : virtual id, i.e. the id seen from the pid namespace of
1730 *                     current.
1731 * task_xid_nr_ns()  : id seen from the ns specified;
1732 *
1733 * set_task_vxid()   : assigns a virtual id to a task;
1734 *
1735 * see also pid_nr() etc in include/linux/pid.h
1736 */
1737pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
1738                        struct pid_namespace *ns);
1739
1740static inline pid_t task_pid_nr(struct task_struct *tsk)
1741{
1742        return tsk->pid;
1743}
1744
1745static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
1746                                        struct pid_namespace *ns)
1747{
1748        return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1749}
1750
1751static inline pid_t task_pid_vnr(struct task_struct *tsk)
1752{
1753        return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1754}
1755
1756
1757static inline pid_t task_tgid_nr(struct task_struct *tsk)
1758{
1759        return tsk->tgid;
1760}
1761
1762pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1763
1764static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1765{
1766        return pid_vnr(task_tgid(tsk));
1767}
1768
1769
1770static inline int pid_alive(const struct task_struct *p);
1771static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1772{
1773        pid_t pid = 0;
1774
1775        rcu_read_lock();
1776        if (pid_alive(tsk))
1777                pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1778        rcu_read_unlock();
1779
1780        return pid;
1781}
1782
1783static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1784{
1785        return task_ppid_nr_ns(tsk, &init_pid_ns);
1786}
1787
1788static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
1789                                        struct pid_namespace *ns)
1790{
1791        return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1792}
1793
1794static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1795{
1796        return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1797}
1798
1799
1800static inline pid_t task_session_nr_ns(struct task_struct *tsk,
1801                                        struct pid_namespace *ns)
1802{
1803        return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1804}
1805
1806static inline pid_t task_session_vnr(struct task_struct *tsk)
1807{
1808        return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1809}
1810
1811/* obsolete, do not use */
1812static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1813{
1814        return task_pgrp_nr_ns(tsk, &init_pid_ns);
1815}
1816
1817/**
1818 * pid_alive - check that a task structure is not stale
1819 * @p: Task structure to be checked.
1820 *
1821 * Test if a process is not yet dead (at most zombie state)
1822 * If pid_alive fails, then pointers within the task structure
1823 * can be stale and must not be dereferenced.
1824 *
1825 * Return: 1 if the process is alive. 0 otherwise.
1826 */
1827static inline int pid_alive(const struct task_struct *p)
1828{
1829        return p->pids[PIDTYPE_PID].pid != NULL;
1830}
1831
1832/**
1833 * is_global_init - check if a task structure is init
1834 * @tsk: Task structure to be checked.
1835 *
1836 * Check if a task structure is the first user space task the kernel created.
1837 *
1838 * Return: 1 if the task structure is init. 0 otherwise.
1839 */
1840static inline int is_global_init(struct task_struct *tsk)
1841{
1842        return tsk->pid == 1;
1843}
1844
1845extern struct pid *cad_pid;
1846
1847extern void free_task(struct task_struct *tsk);
1848#define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
1849
1850extern void __put_task_struct(struct task_struct *t);
1851
1852static inline void put_task_struct(struct task_struct *t)
1853{
1854        if (atomic_dec_and_test(&t->usage))
1855                __put_task_struct(t);
1856}
1857
1858#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1859extern void task_cputime(struct task_struct *t,
1860                         cputime_t *utime, cputime_t *stime);
1861extern void task_cputime_scaled(struct task_struct *t,
1862                                cputime_t *utimescaled, cputime_t *stimescaled);
1863extern cputime_t task_gtime(struct task_struct *t);
1864#else
1865static inline void task_cputime(struct task_struct *t,
1866                                cputime_t *utime, cputime_t *stime)
1867{
1868        if (utime)
1869                *utime = t->utime;
1870        if (stime)
1871                *stime = t->stime;
1872}
1873
1874static inline void task_cputime_scaled(struct task_struct *t,
1875                                       cputime_t *utimescaled,
1876                                       cputime_t *stimescaled)
1877{
1878        if (utimescaled)
1879                *utimescaled = t->utimescaled;
1880        if (stimescaled)
1881                *stimescaled = t->stimescaled;
1882}
1883
1884static inline cputime_t task_gtime(struct task_struct *t)
1885{
1886        return t->gtime;
1887}
1888#endif
1889extern void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
1890extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
1891
1892/*
1893 * Per process flags
1894 */
1895#define PF_EXITING      0x00000004      /* getting shut down */
1896#define PF_EXITPIDONE   0x00000008      /* pi exit done on shut down */
1897#define PF_VCPU         0x00000010      /* I'm a virtual CPU */
1898#define PF_WQ_WORKER    0x00000020      /* I'm a workqueue worker */
1899#define PF_FORKNOEXEC   0x00000040      /* forked but didn't exec */
1900#define PF_MCE_PROCESS  0x00000080      /* process policy on mce errors */
1901#define PF_SUPERPRIV    0x00000100      /* used super-user privileges */
1902#define PF_DUMPCORE     0x00000200      /* dumped core */
1903#define PF_SIGNALED     0x00000400      /* killed by a signal */
1904#define PF_MEMALLOC     0x00000800      /* Allocating memory */
1905#define PF_NPROC_EXCEEDED 0x00001000    /* set_user noticed that RLIMIT_NPROC was exceeded */
1906#define PF_USED_MATH    0x00002000      /* if unset the fpu must be initialized before use */
1907#define PF_USED_ASYNC   0x00004000      /* used async_schedule*(), used by module init */
1908#define PF_NOFREEZE     0x00008000      /* this thread should not be frozen */
1909#define PF_FROZEN       0x00010000      /* frozen for system suspend */
1910#define PF_FSTRANS      0x00020000      /* inside a filesystem transaction */
1911#define PF_KSWAPD       0x00040000      /* I am kswapd */
1912#define PF_MEMALLOC_NOIO 0x00080000     /* Allocating memory without IO involved */
1913#define PF_LESS_THROTTLE 0x00100000     /* Throttle me less: I clean memory */
1914#define PF_KTHREAD      0x00200000      /* I am a kernel thread */
1915#define PF_RANDOMIZE    0x00400000      /* randomize virtual address space */
1916#define PF_SWAPWRITE    0x00800000      /* Allowed to write to swap */
1917#define PF_SPREAD_PAGE  0x01000000      /* Spread page cache over cpuset */
1918#define PF_SPREAD_SLAB  0x02000000      /* Spread some slab caches over cpuset */
1919#define PF_NO_SETAFFINITY 0x04000000    /* Userland is not allowed to meddle with cpus_allowed */
1920#define PF_MCE_EARLY    0x08000000      /* Early kill for mce process policy */
1921#define PF_MUTEX_TESTER 0x20000000      /* Thread belongs to the rt mutex tester */
1922#define PF_FREEZER_SKIP 0x40000000      /* Freezer should not count it as freezable */
1923#define PF_SUSPEND_TASK 0x80000000      /* this thread called freeze_processes and should not be frozen */
1924
1925/*
1926 * Only the _current_ task can read/write to tsk->flags, but other
1927 * tasks can access tsk->flags in readonly mode for example
1928 * with tsk_used_math (like during threaded core dumping).
1929 * There is however an exception to this rule during ptrace
1930 * or during fork: the ptracer task is allowed to write to the
1931 * child->flags of its traced child (same goes for fork, the parent
1932 * can write to the child->flags), because we're guaranteed the
1933 * child is not running and in turn not changing child->flags
1934 * at the same time the parent does it.
1935 */
1936#define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1937#define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1938#define clear_used_math() clear_stopped_child_used_math(current)
1939#define set_used_math() set_stopped_child_used_math(current)
1940#define conditional_stopped_child_used_math(condition, child) \
1941        do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1942#define conditional_used_math(condition) \
1943        conditional_stopped_child_used_math(condition, current)
1944#define copy_to_stopped_child_used_math(child) \
1945        do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1946/* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1947#define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1948#define used_math() tsk_used_math(current)
1949
1950/* __GFP_IO isn't allowed if PF_MEMALLOC_NOIO is set in current->flags */
1951static inline gfp_t memalloc_noio_flags(gfp_t flags)
1952{
1953        if (unlikely(current->flags & PF_MEMALLOC_NOIO))
1954                flags &= ~__GFP_IO;
1955        return flags;
1956}
1957
1958static inline unsigned int memalloc_noio_save(void)
1959{
1960        unsigned int flags = current->flags & PF_MEMALLOC_NOIO;
1961        current->flags |= PF_MEMALLOC_NOIO;
1962        return flags;
1963}
1964
1965static inline void memalloc_noio_restore(unsigned int flags)
1966{
1967        current->flags = (current->flags & ~PF_MEMALLOC_NOIO) | flags;
1968}
1969
1970/*
1971 * task->jobctl flags
1972 */
1973#define JOBCTL_STOP_SIGMASK     0xffff  /* signr of the last group stop */
1974
1975#define JOBCTL_STOP_DEQUEUED_BIT 16     /* stop signal dequeued */
1976#define JOBCTL_STOP_PENDING_BIT 17      /* task should stop for group stop */
1977#define JOBCTL_STOP_CONSUME_BIT 18      /* consume group stop count */
1978#define JOBCTL_TRAP_STOP_BIT    19      /* trap for STOP */
1979#define JOBCTL_TRAP_NOTIFY_BIT  20      /* trap for NOTIFY */
1980#define JOBCTL_TRAPPING_BIT     21      /* switching to TRACED */
1981#define JOBCTL_LISTENING_BIT    22      /* ptracer is listening for events */
1982
1983#define JOBCTL_STOP_DEQUEUED    (1 << JOBCTL_STOP_DEQUEUED_BIT)
1984#define JOBCTL_STOP_PENDING     (1 << JOBCTL_STOP_PENDING_BIT)
1985#define JOBCTL_STOP_CONSUME     (1 << JOBCTL_STOP_CONSUME_BIT)
1986#define JOBCTL_TRAP_STOP        (1 << JOBCTL_TRAP_STOP_BIT)
1987#define JOBCTL_TRAP_NOTIFY      (1 << JOBCTL_TRAP_NOTIFY_BIT)
1988#define JOBCTL_TRAPPING         (1 << JOBCTL_TRAPPING_BIT)
1989#define JOBCTL_LISTENING        (1 << JOBCTL_LISTENING_BIT)
1990
1991#define JOBCTL_TRAP_MASK        (JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
1992#define JOBCTL_PENDING_MASK     (JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)
1993
1994extern bool task_set_jobctl_pending(struct task_struct *task,
1995                                    unsigned int mask);
1996extern void task_clear_jobctl_trapping(struct task_struct *task);
1997extern void task_clear_jobctl_pending(struct task_struct *task,
1998                                      unsigned int mask);
1999
2000#ifdef CONFIG_PREEMPT_RCU
2001
2002#define RCU_READ_UNLOCK_BLOCKED (1 << 0) /* blocked while in RCU read-side. */
2003#define RCU_READ_UNLOCK_NEED_QS (1 << 1) /* RCU core needs CPU response. */
2004
2005static inline void rcu_copy_process(struct task_struct *p)
2006{
2007        p->rcu_read_lock_nesting = 0;
2008        p->rcu_read_unlock_special = 0;
2009#ifdef CONFIG_TREE_PREEMPT_RCU
2010        p->rcu_blocked_node = NULL;
2011#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
2012#ifdef CONFIG_RCU_BOOST
2013        p->rcu_boost_mutex = NULL;
2014#endif /* #ifdef CONFIG_RCU_BOOST */
2015        INIT_LIST_HEAD(&p->rcu_node_entry);
2016}
2017
2018#else
2019
2020static inline void rcu_copy_process(struct task_struct *p)
2021{
2022}
2023
2024#endif
2025
2026static inline void tsk_restore_flags(struct task_struct *task,
2027                                unsigned long orig_flags, unsigned long flags)
2028{
2029        task->flags &= ~flags;
2030        task->flags |= orig_flags & flags;
2031}
2032
2033#ifdef CONFIG_SMP
2034extern void do_set_cpus_allowed(struct task_struct *p,
2035                               const struct cpumask *new_mask);
2036
2037extern int set_cpus_allowed_ptr(struct task_struct *p,
2038                                const struct cpumask *new_mask);
2039#else
2040static inline void do_set_cpus_allowed(struct task_struct *p,
2041                                      const struct cpumask *new_mask)
2042{
2043}
2044static inline int set_cpus_allowed_ptr(struct task_struct *p,
2045                                       const struct cpumask *new_mask)
2046{
2047        if (!cpumask_test_cpu(0, new_mask))
2048                return -EINVAL;
2049        return 0;
2050}
2051#endif
2052
2053#ifdef CONFIG_NO_HZ_COMMON
2054void calc_load_enter_idle(void);
2055void calc_load_exit_idle(void);
2056#else
2057static inline void calc_load_enter_idle(void) { }
2058static inline void calc_load_exit_idle(void) { }
2059#endif /* CONFIG_NO_HZ_COMMON */
2060
2061#ifndef CONFIG_CPUMASK_OFFSTACK
2062static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
2063{
2064        return set_cpus_allowed_ptr(p, &new_mask);
2065}
2066#endif
2067
2068/*
2069 * Do not use outside of architecture code which knows its limitations.
2070 *
2071 * sched_clock() has no promise of monotonicity or bounded drift between
2072 * CPUs, use (which you should not) requires disabling IRQs.
2073 *
2074 * Please use one of the three interfaces below.
2075 */
2076extern unsigned long long notrace sched_clock(void);
2077/*
2078 * See the comment in kernel/sched/clock.c
2079 */
2080extern u64 cpu_clock(int cpu);
2081extern u64 local_clock(void);
2082extern u64 sched_clock_cpu(int cpu);
2083
2084
2085extern void sched_clock_init(void);
2086
2087#ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
2088static inline void sched_clock_tick(void)
2089{
2090}
2091
2092static inline void sched_clock_idle_sleep_event(void)
2093{
2094}
2095
2096static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
2097{
2098}
2099#else
2100/*
2101 * Architectures can set this to 1 if they have specified
2102 * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
2103 * but then during bootup it turns out that sched_clock()
2104 * is reliable after all:
2105 */
2106extern int sched_clock_stable(void);
2107extern void set_sched_clock_stable(void);
2108extern void clear_sched_clock_stable(void);
2109
2110extern void sched_clock_tick(void);
2111extern void sched_clock_idle_sleep_event(void);
2112extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2113#endif
2114
2115#ifdef CONFIG_IRQ_TIME_ACCOUNTING
2116/*
2117 * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
2118 * The reason for this explicit opt-in is not to have perf penalty with
2119 * slow sched_clocks.
2120 */
2121extern void enable_sched_clock_irqtime(void);
2122extern void disable_sched_clock_irqtime(void);
2123#else
2124static inline void enable_sched_clock_irqtime(void) {}
2125static inline void disable_sched_clock_irqtime(void) {}
2126#endif
2127
2128extern unsigned long long
2129task_sched_runtime(struct task_struct *task);
2130
2131/* sched_exec is called by processes performing an exec */
2132#ifdef CONFIG_SMP
2133extern void sched_exec(void);
2134#else
2135#define sched_exec()   {}
2136#endif
2137
2138extern void sched_clock_idle_sleep_event(void);
2139extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2140
2141#ifdef CONFIG_HOTPLUG_CPU
2142extern void idle_task_exit(void);
2143#else
2144static inline void idle_task_exit(void) {}
2145#endif
2146
2147#if defined(CONFIG_NO_HZ_COMMON) && defined(CONFIG_SMP)
2148extern void wake_up_nohz_cpu(int cpu);
2149#else
2150static inline void wake_up_nohz_cpu(int cpu) { }
2151#endif
2152
2153#ifdef CONFIG_NO_HZ_FULL
2154extern bool sched_can_stop_tick(void);
2155extern u64 scheduler_tick_max_deferment(void);
2156#else
2157static inline bool sched_can_stop_tick(void) { return false; }
2158#endif
2159
2160#ifdef CONFIG_SCHED_AUTOGROUP
2161extern void sched_autogroup_create_attach(struct task_struct *p);
2162extern void sched_autogroup_detach(struct task_struct *p);
2163extern void sched_autogroup_fork(struct signal_struct *sig);
2164extern void sched_autogroup_exit(struct signal_struct *sig);
2165#ifdef CONFIG_PROC_FS
2166extern void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m);
2167extern int proc_sched_autogroup_set_nice(struct task_struct *p, int nice);
2168#endif
2169#else
2170static inline void sched_autogroup_create_attach(struct task_struct *p) { }
2171static inline void sched_autogroup_detach(struct task_struct *p) { }
2172static inline void sched_autogroup_fork(struct signal_struct *sig) { }
2173static inline void sched_autogroup_exit(struct signal_struct *sig) { }
2174#endif
2175
2176extern int yield_to(struct task_struct *p, bool preempt);
2177extern void set_user_nice(struct task_struct *p, long nice);
2178extern int task_prio(const struct task_struct *p);
2179/**
2180 * task_nice - return the nice value of a given task.
2181 * @p: the task in question.
2182 *
2183 * Return: The nice value [ -20 ... 0 ... 19 ].
2184 */
2185static inline int task_nice(const struct task_struct *p)
2186{
2187        return PRIO_TO_NICE((p)->static_prio);
2188}
2189extern int can_nice(const struct task_struct *p, const int nice);
2190extern int task_curr(const struct task_struct *p);
2191extern int idle_cpu(int cpu);
2192extern int sched_setscheduler(struct task_struct *, int,
2193                              const struct sched_param *);
2194extern int sched_setscheduler_nocheck(struct task_struct *, int,
2195                                      const struct sched_param *);
2196extern int sched_setattr(struct task_struct *,
2197                         const struct sched_attr *);
2198extern struct task_struct *idle_task(int cpu);
2199/**
2200 * is_idle_task - is the specified task an idle task?
2201 * @p: the task in question.
2202 *
2203 * Return: 1 if @p is an idle task. 0 otherwise.
2204 */
2205static inline bool is_idle_task(const struct task_struct *p)
2206{
2207        return p->pid == 0;
2208}
2209extern struct task_struct *curr_task(int cpu);
2210extern void set_curr_task(int cpu, struct task_struct *p);
2211
2212void yield(void);
2213
2214/*
2215 * The default (Linux) execution domain.
2216 */
2217extern struct exec_domain       default_exec_domain;
2218
2219union thread_union {
2220        struct thread_info thread_info;
2221        unsigned long stack[THREAD_SIZE/sizeof(long)];
2222};
2223
2224#ifndef __HAVE_ARCH_KSTACK_END
2225static inline int kstack_end(void *addr)
2226{
2227        /* Reliable end of stack detection:
2228         * Some APM bios versions misalign the stack
2229         */
2230        return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
2231}
2232#endif
2233
2234extern union thread_union init_thread_union;
2235extern struct task_struct init_task;
2236
2237extern struct   mm_struct init_mm;
2238
2239extern struct pid_namespace init_pid_ns;
2240
2241/*
2242 * find a task by one of its numerical ids
2243 *
2244 * find_task_by_pid_ns():
2245 *      finds a task by its pid in the specified namespace
2246 * find_task_by_vpid():
2247 *      finds a task by its virtual pid
2248 *
2249 * see also find_vpid() etc in include/linux/pid.h
2250 */
2251
2252extern struct task_struct *find_task_by_vpid(pid_t nr);
2253extern struct task_struct *find_task_by_pid_ns(pid_t nr,
2254                struct pid_namespace *ns);
2255
2256/* per-UID process charging. */
2257extern struct user_struct * alloc_uid(kuid_t);
2258static inline struct user_struct *get_uid(struct user_struct *u)
2259{
2260        atomic_inc(&u->__count);
2261        return u;
2262}
2263extern void free_uid(struct user_struct *);
2264
2265#include <asm/current.h>
2266
2267extern void xtime_update(unsigned long ticks);
2268
2269extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2270extern int wake_up_process(struct task_struct *tsk);
2271extern void wake_up_new_task(struct task_struct *tsk);
2272#ifdef CONFIG_SMP
2273 extern void kick_process(struct task_struct *tsk);
2274#else
2275 static inline void kick_process(struct task_struct *tsk) { }
2276#endif
2277extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
2278extern void sched_dead(struct task_struct *p);
2279
2280extern void proc_caches_init(void);
2281extern void flush_signals(struct task_struct *);
2282extern void __flush_signals(struct task_struct *);
2283extern void ignore_signals(struct task_struct *);
2284extern void flush_signal_handlers(struct task_struct *, int force_default);
2285extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
2286
2287static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
2288{
2289        unsigned long flags;
2290        int ret;
2291
2292        spin_lock_irqsave(&tsk->sighand->siglock, flags);
2293        ret = dequeue_signal(tsk, mask, info);
2294        spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
2295
2296        return ret;
2297}
2298
2299extern void block_all_signals(int (*notifier)(void *priv), void *priv,
2300                              sigset_t *mask);
2301extern void unblock_all_signals(void);
2302extern void release_task(struct task_struct * p);
2303extern int send_sig_info(int, struct siginfo *, struct task_struct *);
2304extern int force_sigsegv(int, struct task_struct *);
2305extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2306extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
2307extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2308extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *,
2309                                const struct cred *, u32);
2310extern int kill_pgrp(struct pid *pid, int sig, int priv);
2311extern int kill_pid(struct pid *pid, int sig, int priv);
2312extern int kill_proc_info(int, struct siginfo *, pid_t);
2313extern __must_check bool do_notify_parent(struct task_struct *, int);
2314extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
2315extern void force_sig(int, struct task_struct *);
2316extern int send_sig(int, struct task_struct *, int);
2317extern int zap_other_threads(struct task_struct *p);
2318extern struct sigqueue *sigqueue_alloc(void);
2319extern void sigqueue_free(struct sigqueue *);
2320extern int send_sigqueue(struct sigqueue *,  struct task_struct *, int group);
2321extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
2322
2323static inline void restore_saved_sigmask(void)
2324{
2325        if (test_and_clear_restore_sigmask())
2326                __set_current_blocked(&current->saved_sigmask);
2327}
2328
2329static inline sigset_t *sigmask_to_save(void)
2330{
2331        sigset_t *res = &current->blocked;
2332        if (unlikely(test_restore_sigmask()))
2333                res = &current->saved_sigmask;
2334        return res;
2335}
2336
2337static inline int kill_cad_pid(int sig, int priv)
2338{
2339        return kill_pid(cad_pid, sig, priv);
2340}
2341
2342/* These can be the second arg to send_sig_info/send_group_sig_info.  */
2343#define SEND_SIG_NOINFO ((struct siginfo *) 0)
2344#define SEND_SIG_PRIV   ((struct siginfo *) 1)
2345#define SEND_SIG_FORCED ((struct siginfo *) 2)
2346
2347/*
2348 * True if we are on the alternate signal stack.
2349 */
2350static inline int on_sig_stack(unsigned long sp)
2351{
2352#ifdef CONFIG_STACK_GROWSUP
2353        return sp >= current->sas_ss_sp &&
2354                sp - current->sas_ss_sp < current->sas_ss_size;
2355#else
2356        return sp > current->sas_ss_sp &&
2357                sp - current->sas_ss_sp <= current->sas_ss_size;
2358#endif
2359}
2360
2361static inline int sas_ss_flags(unsigned long sp)
2362{
2363        return (current->sas_ss_size == 0 ? SS_DISABLE
2364                : on_sig_stack(sp) ? SS_ONSTACK : 0);
2365}
2366
2367static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig)
2368{
2369        if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))
2370#ifdef CONFIG_STACK_GROWSUP
2371                return current->sas_ss_sp;
2372#else
2373                return current->sas_ss_sp + current->sas_ss_size;
2374#endif
2375        return sp;
2376}
2377
2378/*
2379 * Routines for handling mm_structs
2380 */
2381extern struct mm_struct * mm_alloc(void);
2382
2383/* mmdrop drops the mm and the page tables */
2384extern void __mmdrop(struct mm_struct *);
2385static inline void mmdrop(struct mm_struct * mm)
2386{
2387        if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2388                __mmdrop(mm);
2389}
2390
2391/* mmput gets rid of the mappings and all user-space */
2392extern void mmput(struct mm_struct *);
2393/* Grab a reference to a task's mm, if it is not already going away */
2394extern struct mm_struct *get_task_mm(struct task_struct *task);
2395/*
2396 * Grab a reference to a task's mm, if it is not already going away
2397 * and ptrace_may_access with the mode parameter passed to it
2398 * succeeds.
2399 */
2400extern struct mm_struct *mm_access(struct task_struct *task, unsigned int mode);
2401/* Remove the current tasks stale references to the old mm_struct */
2402extern void mm_release(struct task_struct *, struct mm_struct *);
2403
2404extern int copy_thread(unsigned long, unsigned long, unsigned long,
2405                        struct task_struct *);
2406extern void flush_thread(void);
2407extern void exit_thread(void);
2408
2409extern void exit_files(struct task_struct *);
2410extern void __cleanup_sighand(struct sighand_struct *);
2411
2412extern void exit_itimers(struct signal_struct *);
2413extern void flush_itimer_signals(void);
2414
2415extern void do_group_exit(int);
2416
2417extern int do_execve(struct filename *,
2418                     const char __user * const __user *,
2419                     const char __user * const __user *);
2420extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
2421struct task_struct *fork_idle(int);
2422extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
2423
2424extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
2425static inline void set_task_comm(struct task_struct *tsk, const char *from)
2426{
2427        __set_task_comm(tsk, from, false);
2428}
2429extern char *get_task_comm(char *to, struct task_struct *tsk);
2430
2431#ifdef CONFIG_SMP
2432void scheduler_ipi(void);
2433extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
2434#else
2435static inline void scheduler_ipi(void) { }
2436static inline unsigned long wait_task_inactive(struct task_struct *p,
2437                                               long match_state)
2438{
2439        return 1;
2440}
2441#endif
2442
2443#define next_task(p) \
2444        list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
2445
2446#define for_each_process(p) \
2447        for (p = &init_task ; (p = next_task(p)) != &init_task ; )
2448
2449extern bool current_is_single_threaded(void);
2450
2451/*
2452 * Careful: do_each_thread/while_each_thread is a double loop so
2453 *          'break' will not work as expected - use goto instead.
2454 */
2455#define do_each_thread(g, t) \
2456        for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
2457
2458#define while_each_thread(g, t) \
2459        while ((t = next_thread(t)) != g)
2460
2461#define __for_each_thread(signal, t)    \
2462        list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node)
2463
2464#define for_each_thread(p, t)           \
2465        __for_each_thread((p)->signal, t)
2466
2467/* Careful: this is a double loop, 'break' won't work as expected. */
2468#define for_each_process_thread(p, t)   \
2469        for_each_process(p) for_each_thread(p, t)
2470
2471static inline int get_nr_threads(struct task_struct *tsk)
2472{
2473        return tsk->signal->nr_threads;
2474}
2475
2476static inline bool thread_group_leader(struct task_struct *p)
2477{
2478        return p->exit_signal >= 0;
2479}
2480
2481/* Do to the insanities of de_thread it is possible for a process
2482 * to have the pid of the thread group leader without actually being
2483 * the thread group leader.  For iteration through the pids in proc
2484 * all we care about is that we have a task with the appropriate
2485 * pid, we don't actually care if we have the right task.
2486 */
2487static inline bool has_group_leader_pid(struct task_struct *p)
2488{
2489        return task_pid(p) == p->signal->leader_pid;
2490}
2491
2492static inline
2493bool same_thread_group(struct task_struct *p1, struct task_struct *p2)
2494{
2495        return p1->signal == p2->signal;
2496}
2497
2498static inline struct task_struct *next_thread(const struct task_struct *p)
2499{
2500        return list_entry_rcu(p->thread_group.next,
2501                              struct task_struct, thread_group);
2502}
2503
2504static inline int thread_group_empty(struct task_struct *p)
2505{
2506        return list_empty(&p->thread_group);
2507}
2508
2509#define delay_group_leader(p) \
2510                (thread_group_leader(p) && !thread_group_empty(p))
2511
2512/*
2513 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
2514 * subscriptions and synchronises with wait4().  Also used in procfs.  Also
2515 * pins the final release of task.io_context.  Also protects ->cpuset and
2516 * ->cgroup.subsys[]. And ->vfork_done.
2517 *
2518 * Nests both inside and outside of read_lock(&tasklist_lock).
2519 * It must not be nested with write_lock_irq(&tasklist_lock),
2520 * neither inside nor outside.
2521 */
2522static inline void task_lock(struct task_struct *p)
2523{
2524        spin_lock(&p->alloc_lock);
2525}
2526
2527static inline void task_unlock(struct task_struct *p)
2528{
2529        spin_unlock(&p->alloc_lock);
2530}
2531
2532extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
2533                                                        unsigned long *flags);
2534
2535static inline struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
2536                                                       unsigned long *flags)
2537{
2538        struct sighand_struct *ret;
2539
2540        ret = __lock_task_sighand(tsk, flags);
2541        (void)__cond_lock(&tsk->sighand->siglock, ret);
2542        return ret;
2543}
2544
2545static inline void unlock_task_sighand(struct task_struct *tsk,
2546                                                unsigned long *flags)
2547{
2548        spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
2549}
2550
2551#ifdef CONFIG_CGROUPS
2552static inline void threadgroup_change_begin(struct task_struct *tsk)
2553{
2554        down_read(&tsk->signal->group_rwsem);
2555}
2556static inline void threadgroup_change_end(struct task_struct *tsk)
2557{
2558        up_read(&tsk->signal->group_rwsem);
2559}
2560
2561/**
2562 * threadgroup_lock - lock threadgroup
2563 * @tsk: member task of the threadgroup to lock
2564 *
2565 * Lock the threadgroup @tsk belongs to.  No new task is allowed to enter
2566 * and member tasks aren't allowed to exit (as indicated by PF_EXITING) or
2567 * change ->group_leader/pid.  This is useful for cases where the threadgroup
2568 * needs to stay stable across blockable operations.
2569 *
2570 * fork and exit paths explicitly call threadgroup_change_{begin|end}() for
2571 * synchronization.  While held, no new task will be added to threadgroup
2572 * and no existing live task will have its PF_EXITING set.
2573 *
2574 * de_thread() does threadgroup_change_{begin|end}() when a non-leader
2575 * sub-thread becomes a new leader.
2576 */
2577static inline void threadgroup_lock(struct task_struct *tsk)
2578{
2579        down_write(&tsk->signal->group_rwsem);
2580}
2581
2582/**
2583 * threadgroup_unlock - unlock threadgroup
2584 * @tsk: member task of the threadgroup to unlock
2585 *
2586 * Reverse threadgroup_lock().
2587 */
2588static inline void threadgroup_unlock(struct task_struct *tsk)
2589{
2590        up_write(&tsk->signal->group_rwsem);
2591}
2592#else
2593static inline void threadgroup_change_begin(struct task_struct *tsk) {}
2594static inline void threadgroup_change_end(struct task_struct *tsk) {}
2595static inline void threadgroup_lock(struct task_struct *tsk) {}
2596static inline void threadgroup_unlock(struct task_struct *tsk) {}
2597#endif
2598
2599#ifndef __HAVE_THREAD_FUNCTIONS
2600
2601#define task_thread_info(task)  ((struct thread_info *)(task)->stack)
2602#define task_stack_page(task)   ((task)->stack)
2603
2604static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
2605{
2606        *task_thread_info(p) = *task_thread_info(org);
2607        task_thread_info(p)->task = p;
2608}
2609
2610static inline unsigned long *end_of_stack(struct task_struct *p)
2611{
2612        return (unsigned long *)(task_thread_info(p) + 1);
2613}
2614
2615#endif
2616
2617static inline int object_is_on_stack(void *obj)
2618{
2619        void *stack = task_stack_page(current);
2620
2621        return (obj >= stack) && (obj < (stack + THREAD_SIZE));
2622}
2623
2624extern void thread_info_cache_init(void);
2625
2626#ifdef CONFIG_DEBUG_STACK_USAGE
2627static inline unsigned long stack_not_used(struct task_struct *p)
2628{
2629        unsigned long *n = end_of_stack(p);
2630
2631        do {    /* Skip over canary */
2632                n++;
2633        } while (!*n);
2634
2635        return (unsigned long)n - (unsigned long)end_of_stack(p);
2636}
2637#endif
2638
2639/* set thread flags in other task's structures
2640 * - see asm/thread_info.h for TIF_xxxx flags available
2641 */
2642static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2643{
2644        set_ti_thread_flag(task_thread_info(tsk), flag);
2645}
2646
2647static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2648{
2649        clear_ti_thread_flag(task_thread_info(tsk), flag);
2650}
2651
2652static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2653{
2654        return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2655}
2656
2657static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2658{
2659        return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2660}
2661
2662static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2663{
2664        return test_ti_thread_flag(task_thread_info(tsk), flag);
2665}
2666
2667static inline void set_tsk_need_resched(struct task_struct *tsk)
2668{
2669        set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2670}
2671
2672static inline void clear_tsk_need_resched(struct task_struct *tsk)
2673{
2674        clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2675}
2676
2677static inline int test_tsk_need_resched(struct task_struct *tsk)
2678{
2679        return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2680}
2681
2682static inline int restart_syscall(void)
2683{
2684        set_tsk_thread_flag(current, TIF_SIGPENDING);
2685        return -ERESTARTNOINTR;
2686}
2687
2688static inline int signal_pending(struct task_struct *p)
2689{
2690        return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
2691}
2692
2693static inline int __fatal_signal_pending(struct task_struct *p)
2694{
2695        return unlikely(sigismember(&p->pending.signal, SIGKILL));
2696}
2697
2698static inline int fatal_signal_pending(struct task_struct *p)
2699{
2700        return signal_pending(p) && __fatal_signal_pending(p);
2701}
2702
2703static inline int signal_pending_state(long state, struct task_struct *p)
2704{
2705        if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
2706                return 0;
2707        if (!signal_pending(p))
2708                return 0;
2709
2710        return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
2711}
2712
2713/*
2714 * cond_resched() and cond_resched_lock(): latency reduction via
2715 * explicit rescheduling in places that are safe. The return
2716 * value indicates whether a reschedule was done in fact.
2717 * cond_resched_lock() will drop the spinlock before scheduling,
2718 * cond_resched_softirq() will enable bhs before scheduling.
2719 */
2720extern int _cond_resched(void);
2721
2722#define cond_resched() ({                       \
2723        __might_sleep(__FILE__, __LINE__, 0);   \
2724        _cond_resched();                        \
2725})
2726
2727extern int __cond_resched_lock(spinlock_t *lock);
2728
2729#ifdef CONFIG_PREEMPT_COUNT
2730#define PREEMPT_LOCK_OFFSET     PREEMPT_OFFSET
2731#else
2732#define PREEMPT_LOCK_OFFSET     0
2733#endif
2734
2735#define cond_resched_lock(lock) ({                              \
2736        __might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET); \
2737        __cond_resched_lock(lock);                              \
2738})
2739
2740extern int __cond_resched_softirq(void);
2741
2742#define cond_resched_softirq() ({                                       \
2743        __might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET);      \
2744        __cond_resched_softirq();                                       \
2745})
2746
2747static inline void cond_resched_rcu(void)
2748{
2749#if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
2750        rcu_read_unlock();
2751        cond_resched();
2752        rcu_read_lock();
2753#endif
2754}
2755
2756/*
2757 * Does a critical section need to be broken due to another
2758 * task waiting?: (technically does not depend on CONFIG_PREEMPT,
2759 * but a general need for low latency)
2760 */
2761static inline int spin_needbreak(spinlock_t *lock)
2762{
2763#ifdef CONFIG_PREEMPT
2764        return spin_is_contended(lock);
2765#else
2766        return 0;
2767#endif
2768}
2769
2770/*
2771 * Idle thread specific functions to determine the need_resched
2772 * polling state.
2773 */
2774#ifdef TIF_POLLING_NRFLAG
2775static inline int tsk_is_polling(struct task_struct *p)
2776{
2777        return test_tsk_thread_flag(p, TIF_POLLING_NRFLAG);
2778}
2779
2780static inline void __current_set_polling(void)
2781{
2782        set_thread_flag(TIF_POLLING_NRFLAG);
2783}
2784
2785static inline bool __must_check current_set_polling_and_test(void)
2786{
2787        __current_set_polling();
2788
2789        /*
2790         * Polling state must be visible before we test NEED_RESCHED,
2791         * paired by resched_task()
2792         */
2793        smp_mb__after_atomic();
2794
2795        return unlikely(tif_need_resched());
2796}
2797
2798static inline void __current_clr_polling(void)
2799{
2800        clear_thread_flag(TIF_POLLING_NRFLAG);
2801}
2802
2803static inline bool __must_check current_clr_polling_and_test(void)
2804{
2805        __current_clr_polling();
2806
2807        /*
2808         * Polling state must be visible before we test NEED_RESCHED,
2809         * paired by resched_task()
2810         */
2811        smp_mb__after_atomic();
2812
2813        return unlikely(tif_need_resched());
2814}
2815
2816#else
2817static inline int tsk_is_polling(struct task_struct *p) { return 0; }
2818static inline void __current_set_polling(void) { }
2819static inline void __current_clr_polling(void) { }
2820
2821static inline bool __must_check current_set_polling_and_test(void)
2822{
2823        return unlikely(tif_need_resched());
2824}
2825static inline bool __must_check current_clr_polling_and_test(void)
2826{
2827        return unlikely(tif_need_resched());
2828}
2829#endif
2830
2831static inline void current_clr_polling(void)
2832{
2833        __current_clr_polling();
2834
2835        /*
2836         * Ensure we check TIF_NEED_RESCHED after we clear the polling bit.
2837         * Once the bit is cleared, we'll get IPIs with every new
2838         * TIF_NEED_RESCHED and the IPI handler, scheduler_ipi(), will also
2839         * fold.
2840         */
2841        smp_mb(); /* paired with resched_task() */
2842
2843        preempt_fold_need_resched();
2844}
2845
2846static __always_inline bool need_resched(void)
2847{
2848        return unlikely(tif_need_resched());
2849}
2850
2851/*
2852 * Thread group CPU time accounting.
2853 */
2854void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
2855void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
2856
2857static inline void thread_group_cputime_init(struct signal_struct *sig)
2858{
2859        raw_spin_lock_init(&sig->cputimer.lock);
2860}
2861
2862/*
2863 * Reevaluate whether the task has signals pending delivery.
2864 * Wake the task if so.
2865 * This is required every time the blocked sigset_t changes.
2866 * callers must hold sighand->siglock.
2867 */
2868extern void recalc_sigpending_and_wake(struct task_struct *t);
2869extern void recalc_sigpending(void);
2870
2871extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
2872
2873static inline void signal_wake_up(struct task_struct *t, bool resume)
2874{
2875        signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0);
2876}
2877static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
2878{
2879        signal_wake_up_state(t, resume ? __TASK_TRACED : 0);
2880}
2881
2882/*
2883 * Wrappers for p->thread_info->cpu access. No-op on UP.
2884 */
2885#ifdef CONFIG_SMP
2886
2887static inline unsigned int task_cpu(const struct task_struct *p)
2888{
2889        return task_thread_info(p)->cpu;
2890}
2891
2892static inline int task_node(const struct task_struct *p)
2893{
2894        return cpu_to_node(task_cpu(p));
2895}
2896
2897extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2898
2899#else
2900
2901static inline unsigned int task_cpu(const struct task_struct *p)
2902{
2903        return 0;
2904}
2905
2906static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2907{
2908}
2909
2910#endif /* CONFIG_SMP */
2911
2912extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2913extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2914
2915#ifdef CONFIG_CGROUP_SCHED
2916extern struct task_group root_task_group;
2917#endif /* CONFIG_CGROUP_SCHED */
2918
2919extern int task_can_switch_user(struct user_struct *up,
2920                                        struct task_struct *tsk);
2921
2922#ifdef CONFIG_TASK_XACCT
2923static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2924{
2925        tsk->ioac.rchar += amt;
2926}
2927
2928static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2929{
2930        tsk->ioac.wchar += amt;
2931}
2932
2933static inline void inc_syscr(struct task_struct *tsk)
2934{
2935        tsk->ioac.syscr++;
2936}
2937
2938static inline void inc_syscw(struct task_struct *tsk)
2939{
2940        tsk->ioac.syscw++;
2941}
2942#else
2943static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2944{
2945}
2946
2947static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2948{
2949}
2950
2951static inline void inc_syscr(struct task_struct *tsk)
2952{
2953}
2954
2955static inline void inc_syscw(struct task_struct *tsk)
2956{
2957}
2958#endif
2959
2960#ifndef TASK_SIZE_OF
2961#define TASK_SIZE_OF(tsk)       TASK_SIZE
2962#endif
2963
2964#ifdef CONFIG_MEMCG
2965extern void mm_update_next_owner(struct mm_struct *mm);
2966extern void mm_init_owner(struct mm_struct *mm, struct task_struct *p);
2967#else
2968static inline void mm_update_next_owner(struct mm_struct *mm)
2969{
2970}
2971
2972static inline void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
2973{
2974}
2975#endif /* CONFIG_MEMCG */
2976
2977static inline unsigned long task_rlimit(const struct task_struct *tsk,
2978                unsigned int limit)
2979{
2980        return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_cur);
2981}
2982
2983static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
2984                unsigned int limit)
2985{
2986        return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_max);
2987}
2988
2989static inline unsigned long rlimit(unsigned int limit)
2990{
2991        return task_rlimit(current, limit);
2992}
2993
2994static inline unsigned long rlimit_max(unsigned int limit)
2995{
2996        return task_rlimit_max(current, limit);
2997}
2998
2999#endif
3000