Merge tag 'sound-4.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai...
[deliverable/linux.git] / include / linux / sched.h
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
9 struct 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.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/shm.h>
37 #include <linux/signal.h>
38 #include <linux/compiler.h>
39 #include <linux/completion.h>
40 #include <linux/pid.h>
41 #include <linux/percpu.h>
42 #include <linux/topology.h>
43 #include <linux/proportions.h>
44 #include <linux/seccomp.h>
45 #include <linux/rcupdate.h>
46 #include <linux/rculist.h>
47 #include <linux/rtmutex.h>
48
49 #include <linux/time.h>
50 #include <linux/param.h>
51 #include <linux/resource.h>
52 #include <linux/timer.h>
53 #include <linux/hrtimer.h>
54 #include <linux/task_io_accounting.h>
55 #include <linux/latencytop.h>
56 #include <linux/cred.h>
57 #include <linux/llist.h>
58 #include <linux/uidgid.h>
59 #include <linux/gfp.h>
60 #include <linux/magic.h>
61 #include <linux/cgroup-defs.h>
62
63 #include <asm/processor.h>
64
65 #define SCHED_ATTR_SIZE_VER0 48 /* sizeof first published struct */
66
67 /*
68 * Extended scheduling parameters data structure.
69 *
70 * This is needed because the original struct sched_param can not be
71 * altered without introducing ABI issues with legacy applications
72 * (e.g., in sched_getparam()).
73 *
74 * However, the possibility of specifying more than just a priority for
75 * the tasks may be useful for a wide variety of application fields, e.g.,
76 * multimedia, streaming, automation and control, and many others.
77 *
78 * This variant (sched_attr) is meant at describing a so-called
79 * sporadic time-constrained task. In such model a task is specified by:
80 * - the activation period or minimum instance inter-arrival time;
81 * - the maximum (or average, depending on the actual scheduling
82 * discipline) computation time of all instances, a.k.a. runtime;
83 * - the deadline (relative to the actual activation time) of each
84 * instance.
85 * Very briefly, a periodic (sporadic) task asks for the execution of
86 * some specific computation --which is typically called an instance--
87 * (at most) every period. Moreover, each instance typically lasts no more
88 * than the runtime and must be completed by time instant t equal to
89 * the instance activation time + the deadline.
90 *
91 * This is reflected by the actual fields of the sched_attr structure:
92 *
93 * @size size of the structure, for fwd/bwd compat.
94 *
95 * @sched_policy task's scheduling policy
96 * @sched_flags for customizing the scheduler behaviour
97 * @sched_nice task's nice value (SCHED_NORMAL/BATCH)
98 * @sched_priority task's static priority (SCHED_FIFO/RR)
99 * @sched_deadline representative of the task's deadline
100 * @sched_runtime representative of the task's runtime
101 * @sched_period representative of the task's period
102 *
103 * Given this task model, there are a multiplicity of scheduling algorithms
104 * and policies, that can be used to ensure all the tasks will make their
105 * timing constraints.
106 *
107 * As of now, the SCHED_DEADLINE policy (sched_dl scheduling class) is the
108 * only user of this new interface. More information about the algorithm
109 * available in the scheduling class file or in Documentation/.
110 */
111 struct sched_attr {
112 u32 size;
113
114 u32 sched_policy;
115 u64 sched_flags;
116
117 /* SCHED_NORMAL, SCHED_BATCH */
118 s32 sched_nice;
119
120 /* SCHED_FIFO, SCHED_RR */
121 u32 sched_priority;
122
123 /* SCHED_DEADLINE */
124 u64 sched_runtime;
125 u64 sched_deadline;
126 u64 sched_period;
127 };
128
129 struct futex_pi_state;
130 struct robust_list_head;
131 struct bio_list;
132 struct fs_struct;
133 struct perf_event_context;
134 struct blk_plug;
135 struct filename;
136 struct nameidata;
137
138 #define VMACACHE_BITS 2
139 #define VMACACHE_SIZE (1U << VMACACHE_BITS)
140 #define VMACACHE_MASK (VMACACHE_SIZE - 1)
141
142 /*
143 * These are the constant used to fake the fixed-point load-average
144 * counting. Some notes:
145 * - 11 bit fractions expand to 22 bits by the multiplies: this gives
146 * a load-average precision of 10 bits integer + 11 bits fractional
147 * - if you want to count load-averages more often, you need more
148 * precision, or rounding will get you. With 2-second counting freq,
149 * the EXP_n values would be 1981, 2034 and 2043 if still using only
150 * 11 bit fractions.
151 */
152 extern unsigned long avenrun[]; /* Load averages */
153 extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
154
155 #define FSHIFT 11 /* nr of bits of precision */
156 #define FIXED_1 (1<<FSHIFT) /* 1.0 as fixed-point */
157 #define LOAD_FREQ (5*HZ+1) /* 5 sec intervals */
158 #define EXP_1 1884 /* 1/exp(5sec/1min) as fixed-point */
159 #define EXP_5 2014 /* 1/exp(5sec/5min) */
160 #define EXP_15 2037 /* 1/exp(5sec/15min) */
161
162 #define CALC_LOAD(load,exp,n) \
163 load *= exp; \
164 load += n*(FIXED_1-exp); \
165 load >>= FSHIFT;
166
167 extern unsigned long total_forks;
168 extern int nr_threads;
169 DECLARE_PER_CPU(unsigned long, process_counts);
170 extern int nr_processes(void);
171 extern unsigned long nr_running(void);
172 extern bool single_task_running(void);
173 extern unsigned long nr_iowait(void);
174 extern unsigned long nr_iowait_cpu(int cpu);
175 extern void get_iowait_load(unsigned long *nr_waiters, unsigned long *load);
176
177 extern void calc_global_load(unsigned long ticks);
178
179 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
180 extern void update_cpu_load_nohz(void);
181 #else
182 static inline void update_cpu_load_nohz(void) { }
183 #endif
184
185 extern unsigned long get_parent_ip(unsigned long addr);
186
187 extern void dump_cpu_task(int cpu);
188
189 struct seq_file;
190 struct cfs_rq;
191 struct task_group;
192 #ifdef CONFIG_SCHED_DEBUG
193 extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
194 extern void proc_sched_set_task(struct task_struct *p);
195 #endif
196
197 /*
198 * Task state bitmask. NOTE! These bits are also
199 * encoded in fs/proc/array.c: get_task_state().
200 *
201 * We have two separate sets of flags: task->state
202 * is about runnability, while task->exit_state are
203 * about the task exiting. Confusing, but this way
204 * modifying one set can't modify the other one by
205 * mistake.
206 */
207 #define TASK_RUNNING 0
208 #define TASK_INTERRUPTIBLE 1
209 #define TASK_UNINTERRUPTIBLE 2
210 #define __TASK_STOPPED 4
211 #define __TASK_TRACED 8
212 /* in tsk->exit_state */
213 #define EXIT_DEAD 16
214 #define EXIT_ZOMBIE 32
215 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD)
216 /* in tsk->state again */
217 #define TASK_DEAD 64
218 #define TASK_WAKEKILL 128
219 #define TASK_WAKING 256
220 #define TASK_PARKED 512
221 #define TASK_NOLOAD 1024
222 #define TASK_STATE_MAX 2048
223
224 #define TASK_STATE_TO_CHAR_STR "RSDTtXZxKWPN"
225
226 extern char ___assert_task_state[1 - 2*!!(
227 sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
228
229 /* Convenience macros for the sake of set_task_state */
230 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
231 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED)
232 #define TASK_TRACED (TASK_WAKEKILL | __TASK_TRACED)
233
234 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
235
236 /* Convenience macros for the sake of wake_up */
237 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
238 #define TASK_ALL (TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
239
240 /* get_task_state() */
241 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \
242 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
243 __TASK_TRACED | EXIT_ZOMBIE | EXIT_DEAD)
244
245 #define task_is_traced(task) ((task->state & __TASK_TRACED) != 0)
246 #define task_is_stopped(task) ((task->state & __TASK_STOPPED) != 0)
247 #define task_is_stopped_or_traced(task) \
248 ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
249 #define task_contributes_to_load(task) \
250 ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
251 (task->flags & PF_FROZEN) == 0 && \
252 (task->state & TASK_NOLOAD) == 0)
253
254 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
255
256 #define __set_task_state(tsk, state_value) \
257 do { \
258 (tsk)->task_state_change = _THIS_IP_; \
259 (tsk)->state = (state_value); \
260 } while (0)
261 #define set_task_state(tsk, state_value) \
262 do { \
263 (tsk)->task_state_change = _THIS_IP_; \
264 smp_store_mb((tsk)->state, (state_value)); \
265 } while (0)
266
267 /*
268 * set_current_state() includes a barrier so that the write of current->state
269 * is correctly serialised wrt the caller's subsequent test of whether to
270 * actually sleep:
271 *
272 * set_current_state(TASK_UNINTERRUPTIBLE);
273 * if (do_i_need_to_sleep())
274 * schedule();
275 *
276 * If the caller does not need such serialisation then use __set_current_state()
277 */
278 #define __set_current_state(state_value) \
279 do { \
280 current->task_state_change = _THIS_IP_; \
281 current->state = (state_value); \
282 } while (0)
283 #define set_current_state(state_value) \
284 do { \
285 current->task_state_change = _THIS_IP_; \
286 smp_store_mb(current->state, (state_value)); \
287 } while (0)
288
289 #else
290
291 #define __set_task_state(tsk, state_value) \
292 do { (tsk)->state = (state_value); } while (0)
293 #define set_task_state(tsk, state_value) \
294 smp_store_mb((tsk)->state, (state_value))
295
296 /*
297 * set_current_state() includes a barrier so that the write of current->state
298 * is correctly serialised wrt the caller's subsequent test of whether to
299 * actually sleep:
300 *
301 * set_current_state(TASK_UNINTERRUPTIBLE);
302 * if (do_i_need_to_sleep())
303 * schedule();
304 *
305 * If the caller does not need such serialisation then use __set_current_state()
306 */
307 #define __set_current_state(state_value) \
308 do { current->state = (state_value); } while (0)
309 #define set_current_state(state_value) \
310 smp_store_mb(current->state, (state_value))
311
312 #endif
313
314 /* Task command name length */
315 #define TASK_COMM_LEN 16
316
317 #include <linux/spinlock.h>
318
319 /*
320 * This serializes "schedule()" and also protects
321 * the run-queue from deletions/modifications (but
322 * _adding_ to the beginning of the run-queue has
323 * a separate lock).
324 */
325 extern rwlock_t tasklist_lock;
326 extern spinlock_t mmlist_lock;
327
328 struct task_struct;
329
330 #ifdef CONFIG_PROVE_RCU
331 extern int lockdep_tasklist_lock_is_held(void);
332 #endif /* #ifdef CONFIG_PROVE_RCU */
333
334 extern void sched_init(void);
335 extern void sched_init_smp(void);
336 extern asmlinkage void schedule_tail(struct task_struct *prev);
337 extern void init_idle(struct task_struct *idle, int cpu);
338 extern void init_idle_bootup_task(struct task_struct *idle);
339
340 extern cpumask_var_t cpu_isolated_map;
341
342 extern int runqueue_is_locked(int cpu);
343
344 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
345 extern void nohz_balance_enter_idle(int cpu);
346 extern void set_cpu_sd_state_idle(void);
347 extern int get_nohz_timer_target(void);
348 #else
349 static inline void nohz_balance_enter_idle(int cpu) { }
350 static inline void set_cpu_sd_state_idle(void) { }
351 #endif
352
353 /*
354 * Only dump TASK_* tasks. (0 for all tasks)
355 */
356 extern void show_state_filter(unsigned long state_filter);
357
358 static inline void show_state(void)
359 {
360 show_state_filter(0);
361 }
362
363 extern void show_regs(struct pt_regs *);
364
365 /*
366 * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
367 * task), SP is the stack pointer of the first frame that should be shown in the back
368 * trace (or NULL if the entire call-chain of the task should be shown).
369 */
370 extern void show_stack(struct task_struct *task, unsigned long *sp);
371
372 extern void cpu_init (void);
373 extern void trap_init(void);
374 extern void update_process_times(int user);
375 extern void scheduler_tick(void);
376
377 extern void sched_show_task(struct task_struct *p);
378
379 #ifdef CONFIG_LOCKUP_DETECTOR
380 extern void touch_softlockup_watchdog(void);
381 extern void touch_softlockup_watchdog_sync(void);
382 extern void touch_all_softlockup_watchdogs(void);
383 extern int proc_dowatchdog_thresh(struct ctl_table *table, int write,
384 void __user *buffer,
385 size_t *lenp, loff_t *ppos);
386 extern unsigned int softlockup_panic;
387 void lockup_detector_init(void);
388 #else
389 static inline void touch_softlockup_watchdog(void)
390 {
391 }
392 static inline void touch_softlockup_watchdog_sync(void)
393 {
394 }
395 static inline void touch_all_softlockup_watchdogs(void)
396 {
397 }
398 static inline void lockup_detector_init(void)
399 {
400 }
401 #endif
402
403 #ifdef CONFIG_DETECT_HUNG_TASK
404 void reset_hung_task_detector(void);
405 #else
406 static inline void reset_hung_task_detector(void)
407 {
408 }
409 #endif
410
411 /* Attach to any functions which should be ignored in wchan output. */
412 #define __sched __attribute__((__section__(".sched.text")))
413
414 /* Linker adds these: start and end of __sched functions */
415 extern char __sched_text_start[], __sched_text_end[];
416
417 /* Is this address in the __sched functions? */
418 extern int in_sched_functions(unsigned long addr);
419
420 #define MAX_SCHEDULE_TIMEOUT LONG_MAX
421 extern signed long schedule_timeout(signed long timeout);
422 extern signed long schedule_timeout_interruptible(signed long timeout);
423 extern signed long schedule_timeout_killable(signed long timeout);
424 extern signed long schedule_timeout_uninterruptible(signed long timeout);
425 asmlinkage void schedule(void);
426 extern void schedule_preempt_disabled(void);
427
428 extern long io_schedule_timeout(long timeout);
429
430 static inline void io_schedule(void)
431 {
432 io_schedule_timeout(MAX_SCHEDULE_TIMEOUT);
433 }
434
435 struct nsproxy;
436 struct user_namespace;
437
438 #ifdef CONFIG_MMU
439 extern void arch_pick_mmap_layout(struct mm_struct *mm);
440 extern unsigned long
441 arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
442 unsigned long, unsigned long);
443 extern unsigned long
444 arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
445 unsigned long len, unsigned long pgoff,
446 unsigned long flags);
447 #else
448 static inline void arch_pick_mmap_layout(struct mm_struct *mm) {}
449 #endif
450
451 #define SUID_DUMP_DISABLE 0 /* No setuid dumping */
452 #define SUID_DUMP_USER 1 /* Dump as user of process */
453 #define SUID_DUMP_ROOT 2 /* Dump as root */
454
455 /* mm flags */
456
457 /* for SUID_DUMP_* above */
458 #define MMF_DUMPABLE_BITS 2
459 #define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
460
461 extern void set_dumpable(struct mm_struct *mm, int value);
462 /*
463 * This returns the actual value of the suid_dumpable flag. For things
464 * that are using this for checking for privilege transitions, it must
465 * test against SUID_DUMP_USER rather than treating it as a boolean
466 * value.
467 */
468 static inline int __get_dumpable(unsigned long mm_flags)
469 {
470 return mm_flags & MMF_DUMPABLE_MASK;
471 }
472
473 static inline int get_dumpable(struct mm_struct *mm)
474 {
475 return __get_dumpable(mm->flags);
476 }
477
478 /* coredump filter bits */
479 #define MMF_DUMP_ANON_PRIVATE 2
480 #define MMF_DUMP_ANON_SHARED 3
481 #define MMF_DUMP_MAPPED_PRIVATE 4
482 #define MMF_DUMP_MAPPED_SHARED 5
483 #define MMF_DUMP_ELF_HEADERS 6
484 #define MMF_DUMP_HUGETLB_PRIVATE 7
485 #define MMF_DUMP_HUGETLB_SHARED 8
486
487 #define MMF_DUMP_FILTER_SHIFT MMF_DUMPABLE_BITS
488 #define MMF_DUMP_FILTER_BITS 7
489 #define MMF_DUMP_FILTER_MASK \
490 (((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
491 #define MMF_DUMP_FILTER_DEFAULT \
492 ((1 << MMF_DUMP_ANON_PRIVATE) | (1 << MMF_DUMP_ANON_SHARED) |\
493 (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
494
495 #ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
496 # define MMF_DUMP_MASK_DEFAULT_ELF (1 << MMF_DUMP_ELF_HEADERS)
497 #else
498 # define MMF_DUMP_MASK_DEFAULT_ELF 0
499 #endif
500 /* leave room for more dump flags */
501 #define MMF_VM_MERGEABLE 16 /* KSM may merge identical pages */
502 #define MMF_VM_HUGEPAGE 17 /* set when VM_HUGEPAGE is set on vma */
503 #define MMF_EXE_FILE_CHANGED 18 /* see prctl_set_mm_exe_file() */
504
505 #define MMF_HAS_UPROBES 19 /* has uprobes */
506 #define MMF_RECALC_UPROBES 20 /* MMF_HAS_UPROBES can be wrong */
507
508 #define MMF_INIT_MASK (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
509
510 struct sighand_struct {
511 atomic_t count;
512 struct k_sigaction action[_NSIG];
513 spinlock_t siglock;
514 wait_queue_head_t signalfd_wqh;
515 };
516
517 struct pacct_struct {
518 int ac_flag;
519 long ac_exitcode;
520 unsigned long ac_mem;
521 cputime_t ac_utime, ac_stime;
522 unsigned long ac_minflt, ac_majflt;
523 };
524
525 struct cpu_itimer {
526 cputime_t expires;
527 cputime_t incr;
528 u32 error;
529 u32 incr_error;
530 };
531
532 /**
533 * struct cputime - snaphsot of system and user cputime
534 * @utime: time spent in user mode
535 * @stime: time spent in system mode
536 *
537 * Gathers a generic snapshot of user and system time.
538 */
539 struct cputime {
540 cputime_t utime;
541 cputime_t stime;
542 };
543
544 /**
545 * struct task_cputime - collected CPU time counts
546 * @utime: time spent in user mode, in &cputime_t units
547 * @stime: time spent in kernel mode, in &cputime_t units
548 * @sum_exec_runtime: total time spent on the CPU, in nanoseconds
549 *
550 * This is an extension of struct cputime that includes the total runtime
551 * spent by the task from the scheduler point of view.
552 *
553 * As a result, this structure groups together three kinds of CPU time
554 * that are tracked for threads and thread groups. Most things considering
555 * CPU time want to group these counts together and treat all three
556 * of them in parallel.
557 */
558 struct task_cputime {
559 cputime_t utime;
560 cputime_t stime;
561 unsigned long long sum_exec_runtime;
562 };
563 /* Alternate field names when used to cache expirations. */
564 #define prof_exp stime
565 #define virt_exp utime
566 #define sched_exp sum_exec_runtime
567
568 #define INIT_CPUTIME \
569 (struct task_cputime) { \
570 .utime = 0, \
571 .stime = 0, \
572 .sum_exec_runtime = 0, \
573 }
574
575 /*
576 * This is the atomic variant of task_cputime, which can be used for
577 * storing and updating task_cputime statistics without locking.
578 */
579 struct task_cputime_atomic {
580 atomic64_t utime;
581 atomic64_t stime;
582 atomic64_t sum_exec_runtime;
583 };
584
585 #define INIT_CPUTIME_ATOMIC \
586 (struct task_cputime_atomic) { \
587 .utime = ATOMIC64_INIT(0), \
588 .stime = ATOMIC64_INIT(0), \
589 .sum_exec_runtime = ATOMIC64_INIT(0), \
590 }
591
592 #ifdef CONFIG_PREEMPT_COUNT
593 #define PREEMPT_DISABLED (1 + PREEMPT_ENABLED)
594 #else
595 #define PREEMPT_DISABLED PREEMPT_ENABLED
596 #endif
597
598 /*
599 * Disable preemption until the scheduler is running.
600 * Reset by start_kernel()->sched_init()->init_idle().
601 *
602 * We include PREEMPT_ACTIVE to avoid cond_resched() from working
603 * before the scheduler is active -- see should_resched().
604 */
605 #define INIT_PREEMPT_COUNT (PREEMPT_DISABLED + PREEMPT_ACTIVE)
606
607 /**
608 * struct thread_group_cputimer - thread group interval timer counts
609 * @cputime_atomic: atomic thread group interval timers.
610 * @running: non-zero when there are timers running and
611 * @cputime receives updates.
612 *
613 * This structure contains the version of task_cputime, above, that is
614 * used for thread group CPU timer calculations.
615 */
616 struct thread_group_cputimer {
617 struct task_cputime_atomic cputime_atomic;
618 int running;
619 };
620
621 #include <linux/rwsem.h>
622 struct autogroup;
623
624 /*
625 * NOTE! "signal_struct" does not have its own
626 * locking, because a shared signal_struct always
627 * implies a shared sighand_struct, so locking
628 * sighand_struct is always a proper superset of
629 * the locking of signal_struct.
630 */
631 struct signal_struct {
632 atomic_t sigcnt;
633 atomic_t live;
634 int nr_threads;
635 struct list_head thread_head;
636
637 wait_queue_head_t wait_chldexit; /* for wait4() */
638
639 /* current thread group signal load-balancing target: */
640 struct task_struct *curr_target;
641
642 /* shared signal handling: */
643 struct sigpending shared_pending;
644
645 /* thread group exit support */
646 int group_exit_code;
647 /* overloaded:
648 * - notify group_exit_task when ->count is equal to notify_count
649 * - everyone except group_exit_task is stopped during signal delivery
650 * of fatal signals, group_exit_task processes the signal.
651 */
652 int notify_count;
653 struct task_struct *group_exit_task;
654
655 /* thread group stop support, overloads group_exit_code too */
656 int group_stop_count;
657 unsigned int flags; /* see SIGNAL_* flags below */
658
659 /*
660 * PR_SET_CHILD_SUBREAPER marks a process, like a service
661 * manager, to re-parent orphan (double-forking) child processes
662 * to this process instead of 'init'. The service manager is
663 * able to receive SIGCHLD signals and is able to investigate
664 * the process until it calls wait(). All children of this
665 * process will inherit a flag if they should look for a
666 * child_subreaper process at exit.
667 */
668 unsigned int is_child_subreaper:1;
669 unsigned int has_child_subreaper:1;
670
671 /* POSIX.1b Interval Timers */
672 int posix_timer_id;
673 struct list_head posix_timers;
674
675 /* ITIMER_REAL timer for the process */
676 struct hrtimer real_timer;
677 struct pid *leader_pid;
678 ktime_t it_real_incr;
679
680 /*
681 * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
682 * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
683 * values are defined to 0 and 1 respectively
684 */
685 struct cpu_itimer it[2];
686
687 /*
688 * Thread group totals for process CPU timers.
689 * See thread_group_cputimer(), et al, for details.
690 */
691 struct thread_group_cputimer cputimer;
692
693 /* Earliest-expiration cache. */
694 struct task_cputime cputime_expires;
695
696 struct list_head cpu_timers[3];
697
698 struct pid *tty_old_pgrp;
699
700 /* boolean value for session group leader */
701 int leader;
702
703 struct tty_struct *tty; /* NULL if no tty */
704
705 #ifdef CONFIG_SCHED_AUTOGROUP
706 struct autogroup *autogroup;
707 #endif
708 /*
709 * Cumulative resource counters for dead threads in the group,
710 * and for reaped dead child processes forked by this group.
711 * Live threads maintain their own counters and add to these
712 * in __exit_signal, except for the group leader.
713 */
714 seqlock_t stats_lock;
715 cputime_t utime, stime, cutime, cstime;
716 cputime_t gtime;
717 cputime_t cgtime;
718 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
719 struct cputime prev_cputime;
720 #endif
721 unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
722 unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
723 unsigned long inblock, oublock, cinblock, coublock;
724 unsigned long maxrss, cmaxrss;
725 struct task_io_accounting ioac;
726
727 /*
728 * Cumulative ns of schedule CPU time fo dead threads in the
729 * group, not including a zombie group leader, (This only differs
730 * from jiffies_to_ns(utime + stime) if sched_clock uses something
731 * other than jiffies.)
732 */
733 unsigned long long sum_sched_runtime;
734
735 /*
736 * We don't bother to synchronize most readers of this at all,
737 * because there is no reader checking a limit that actually needs
738 * to get both rlim_cur and rlim_max atomically, and either one
739 * alone is a single word that can safely be read normally.
740 * getrlimit/setrlimit use task_lock(current->group_leader) to
741 * protect this instead of the siglock, because they really
742 * have no need to disable irqs.
743 */
744 struct rlimit rlim[RLIM_NLIMITS];
745
746 #ifdef CONFIG_BSD_PROCESS_ACCT
747 struct pacct_struct pacct; /* per-process accounting information */
748 #endif
749 #ifdef CONFIG_TASKSTATS
750 struct taskstats *stats;
751 #endif
752 #ifdef CONFIG_AUDIT
753 unsigned audit_tty;
754 unsigned audit_tty_log_passwd;
755 struct tty_audit_buf *tty_audit_buf;
756 #endif
757
758 oom_flags_t oom_flags;
759 short oom_score_adj; /* OOM kill score adjustment */
760 short oom_score_adj_min; /* OOM kill score adjustment min value.
761 * Only settable by CAP_SYS_RESOURCE. */
762
763 struct mutex cred_guard_mutex; /* guard against foreign influences on
764 * credential calculations
765 * (notably. ptrace) */
766 };
767
768 /*
769 * Bits in flags field of signal_struct.
770 */
771 #define SIGNAL_STOP_STOPPED 0x00000001 /* job control stop in effect */
772 #define SIGNAL_STOP_CONTINUED 0x00000002 /* SIGCONT since WCONTINUED reap */
773 #define SIGNAL_GROUP_EXIT 0x00000004 /* group exit in progress */
774 #define SIGNAL_GROUP_COREDUMP 0x00000008 /* coredump in progress */
775 /*
776 * Pending notifications to parent.
777 */
778 #define SIGNAL_CLD_STOPPED 0x00000010
779 #define SIGNAL_CLD_CONTINUED 0x00000020
780 #define SIGNAL_CLD_MASK (SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
781
782 #define SIGNAL_UNKILLABLE 0x00000040 /* for init: ignore fatal signals */
783
784 /* If true, all threads except ->group_exit_task have pending SIGKILL */
785 static inline int signal_group_exit(const struct signal_struct *sig)
786 {
787 return (sig->flags & SIGNAL_GROUP_EXIT) ||
788 (sig->group_exit_task != NULL);
789 }
790
791 /*
792 * Some day this will be a full-fledged user tracking system..
793 */
794 struct user_struct {
795 atomic_t __count; /* reference count */
796 atomic_t processes; /* How many processes does this user have? */
797 atomic_t sigpending; /* How many pending signals does this user have? */
798 #ifdef CONFIG_INOTIFY_USER
799 atomic_t inotify_watches; /* How many inotify watches does this user have? */
800 atomic_t inotify_devs; /* How many inotify devs does this user have opened? */
801 #endif
802 #ifdef CONFIG_FANOTIFY
803 atomic_t fanotify_listeners;
804 #endif
805 #ifdef CONFIG_EPOLL
806 atomic_long_t epoll_watches; /* The number of file descriptors currently watched */
807 #endif
808 #ifdef CONFIG_POSIX_MQUEUE
809 /* protected by mq_lock */
810 unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */
811 #endif
812 unsigned long locked_shm; /* How many pages of mlocked shm ? */
813
814 #ifdef CONFIG_KEYS
815 struct key *uid_keyring; /* UID specific keyring */
816 struct key *session_keyring; /* UID's default session keyring */
817 #endif
818
819 /* Hash table maintenance information */
820 struct hlist_node uidhash_node;
821 kuid_t uid;
822
823 #ifdef CONFIG_PERF_EVENTS
824 atomic_long_t locked_vm;
825 #endif
826 };
827
828 extern int uids_sysfs_init(void);
829
830 extern struct user_struct *find_user(kuid_t);
831
832 extern struct user_struct root_user;
833 #define INIT_USER (&root_user)
834
835
836 struct backing_dev_info;
837 struct reclaim_state;
838
839 #ifdef CONFIG_SCHED_INFO
840 struct sched_info {
841 /* cumulative counters */
842 unsigned long pcount; /* # of times run on this cpu */
843 unsigned long long run_delay; /* time spent waiting on a runqueue */
844
845 /* timestamps */
846 unsigned long long last_arrival,/* when we last ran on a cpu */
847 last_queued; /* when we were last queued to run */
848 };
849 #endif /* CONFIG_SCHED_INFO */
850
851 #ifdef CONFIG_TASK_DELAY_ACCT
852 struct task_delay_info {
853 spinlock_t lock;
854 unsigned int flags; /* Private per-task flags */
855
856 /* For each stat XXX, add following, aligned appropriately
857 *
858 * struct timespec XXX_start, XXX_end;
859 * u64 XXX_delay;
860 * u32 XXX_count;
861 *
862 * Atomicity of updates to XXX_delay, XXX_count protected by
863 * single lock above (split into XXX_lock if contention is an issue).
864 */
865
866 /*
867 * XXX_count is incremented on every XXX operation, the delay
868 * associated with the operation is added to XXX_delay.
869 * XXX_delay contains the accumulated delay time in nanoseconds.
870 */
871 u64 blkio_start; /* Shared by blkio, swapin */
872 u64 blkio_delay; /* wait for sync block io completion */
873 u64 swapin_delay; /* wait for swapin block io completion */
874 u32 blkio_count; /* total count of the number of sync block */
875 /* io operations performed */
876 u32 swapin_count; /* total count of the number of swapin block */
877 /* io operations performed */
878
879 u64 freepages_start;
880 u64 freepages_delay; /* wait for memory reclaim */
881 u32 freepages_count; /* total count of memory reclaim */
882 };
883 #endif /* CONFIG_TASK_DELAY_ACCT */
884
885 static inline int sched_info_on(void)
886 {
887 #ifdef CONFIG_SCHEDSTATS
888 return 1;
889 #elif defined(CONFIG_TASK_DELAY_ACCT)
890 extern int delayacct_on;
891 return delayacct_on;
892 #else
893 return 0;
894 #endif
895 }
896
897 enum cpu_idle_type {
898 CPU_IDLE,
899 CPU_NOT_IDLE,
900 CPU_NEWLY_IDLE,
901 CPU_MAX_IDLE_TYPES
902 };
903
904 /*
905 * Increase resolution of cpu_capacity calculations
906 */
907 #define SCHED_CAPACITY_SHIFT 10
908 #define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT)
909
910 /*
911 * Wake-queues are lists of tasks with a pending wakeup, whose
912 * callers have already marked the task as woken internally,
913 * and can thus carry on. A common use case is being able to
914 * do the wakeups once the corresponding user lock as been
915 * released.
916 *
917 * We hold reference to each task in the list across the wakeup,
918 * thus guaranteeing that the memory is still valid by the time
919 * the actual wakeups are performed in wake_up_q().
920 *
921 * One per task suffices, because there's never a need for a task to be
922 * in two wake queues simultaneously; it is forbidden to abandon a task
923 * in a wake queue (a call to wake_up_q() _must_ follow), so if a task is
924 * already in a wake queue, the wakeup will happen soon and the second
925 * waker can just skip it.
926 *
927 * The WAKE_Q macro declares and initializes the list head.
928 * wake_up_q() does NOT reinitialize the list; it's expected to be
929 * called near the end of a function, where the fact that the queue is
930 * not used again will be easy to see by inspection.
931 *
932 * Note that this can cause spurious wakeups. schedule() callers
933 * must ensure the call is done inside a loop, confirming that the
934 * wakeup condition has in fact occurred.
935 */
936 struct wake_q_node {
937 struct wake_q_node *next;
938 };
939
940 struct wake_q_head {
941 struct wake_q_node *first;
942 struct wake_q_node **lastp;
943 };
944
945 #define WAKE_Q_TAIL ((struct wake_q_node *) 0x01)
946
947 #define WAKE_Q(name) \
948 struct wake_q_head name = { WAKE_Q_TAIL, &name.first }
949
950 extern void wake_q_add(struct wake_q_head *head,
951 struct task_struct *task);
952 extern void wake_up_q(struct wake_q_head *head);
953
954 /*
955 * sched-domains (multiprocessor balancing) declarations:
956 */
957 #ifdef CONFIG_SMP
958 #define SD_LOAD_BALANCE 0x0001 /* Do load balancing on this domain. */
959 #define SD_BALANCE_NEWIDLE 0x0002 /* Balance when about to become idle */
960 #define SD_BALANCE_EXEC 0x0004 /* Balance on exec */
961 #define SD_BALANCE_FORK 0x0008 /* Balance on fork, clone */
962 #define SD_BALANCE_WAKE 0x0010 /* Balance on wakeup */
963 #define SD_WAKE_AFFINE 0x0020 /* Wake task to waking CPU */
964 #define SD_SHARE_CPUCAPACITY 0x0080 /* Domain members share cpu power */
965 #define SD_SHARE_POWERDOMAIN 0x0100 /* Domain members share power domain */
966 #define SD_SHARE_PKG_RESOURCES 0x0200 /* Domain members share cpu pkg resources */
967 #define SD_SERIALIZE 0x0400 /* Only a single load balancing instance */
968 #define SD_ASYM_PACKING 0x0800 /* Place busy groups earlier in the domain */
969 #define SD_PREFER_SIBLING 0x1000 /* Prefer to place tasks in a sibling domain */
970 #define SD_OVERLAP 0x2000 /* sched_domains of this level overlap */
971 #define SD_NUMA 0x4000 /* cross-node balancing */
972
973 #ifdef CONFIG_SCHED_SMT
974 static inline int cpu_smt_flags(void)
975 {
976 return SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
977 }
978 #endif
979
980 #ifdef CONFIG_SCHED_MC
981 static inline int cpu_core_flags(void)
982 {
983 return SD_SHARE_PKG_RESOURCES;
984 }
985 #endif
986
987 #ifdef CONFIG_NUMA
988 static inline int cpu_numa_flags(void)
989 {
990 return SD_NUMA;
991 }
992 #endif
993
994 struct sched_domain_attr {
995 int relax_domain_level;
996 };
997
998 #define SD_ATTR_INIT (struct sched_domain_attr) { \
999 .relax_domain_level = -1, \
1000 }
1001
1002 extern int sched_domain_level_max;
1003
1004 struct sched_group;
1005
1006 struct sched_domain {
1007 /* These fields must be setup */
1008 struct sched_domain *parent; /* top domain must be null terminated */
1009 struct sched_domain *child; /* bottom domain must be null terminated */
1010 struct sched_group *groups; /* the balancing groups of the domain */
1011 unsigned long min_interval; /* Minimum balance interval ms */
1012 unsigned long max_interval; /* Maximum balance interval ms */
1013 unsigned int busy_factor; /* less balancing by factor if busy */
1014 unsigned int imbalance_pct; /* No balance until over watermark */
1015 unsigned int cache_nice_tries; /* Leave cache hot tasks for # tries */
1016 unsigned int busy_idx;
1017 unsigned int idle_idx;
1018 unsigned int newidle_idx;
1019 unsigned int wake_idx;
1020 unsigned int forkexec_idx;
1021 unsigned int smt_gain;
1022
1023 int nohz_idle; /* NOHZ IDLE status */
1024 int flags; /* See SD_* */
1025 int level;
1026
1027 /* Runtime fields. */
1028 unsigned long last_balance; /* init to jiffies. units in jiffies */
1029 unsigned int balance_interval; /* initialise to 1. units in ms. */
1030 unsigned int nr_balance_failed; /* initialise to 0 */
1031
1032 /* idle_balance() stats */
1033 u64 max_newidle_lb_cost;
1034 unsigned long next_decay_max_lb_cost;
1035
1036 #ifdef CONFIG_SCHEDSTATS
1037 /* load_balance() stats */
1038 unsigned int lb_count[CPU_MAX_IDLE_TYPES];
1039 unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
1040 unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
1041 unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
1042 unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
1043 unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
1044 unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
1045 unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
1046
1047 /* Active load balancing */
1048 unsigned int alb_count;
1049 unsigned int alb_failed;
1050 unsigned int alb_pushed;
1051
1052 /* SD_BALANCE_EXEC stats */
1053 unsigned int sbe_count;
1054 unsigned int sbe_balanced;
1055 unsigned int sbe_pushed;
1056
1057 /* SD_BALANCE_FORK stats */
1058 unsigned int sbf_count;
1059 unsigned int sbf_balanced;
1060 unsigned int sbf_pushed;
1061
1062 /* try_to_wake_up() stats */
1063 unsigned int ttwu_wake_remote;
1064 unsigned int ttwu_move_affine;
1065 unsigned int ttwu_move_balance;
1066 #endif
1067 #ifdef CONFIG_SCHED_DEBUG
1068 char *name;
1069 #endif
1070 union {
1071 void *private; /* used during construction */
1072 struct rcu_head rcu; /* used during destruction */
1073 };
1074
1075 unsigned int span_weight;
1076 /*
1077 * Span of all CPUs in this domain.
1078 *
1079 * NOTE: this field is variable length. (Allocated dynamically
1080 * by attaching extra space to the end of the structure,
1081 * depending on how many CPUs the kernel has booted up with)
1082 */
1083 unsigned long span[0];
1084 };
1085
1086 static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
1087 {
1088 return to_cpumask(sd->span);
1089 }
1090
1091 extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1092 struct sched_domain_attr *dattr_new);
1093
1094 /* Allocate an array of sched domains, for partition_sched_domains(). */
1095 cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
1096 void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
1097
1098 bool cpus_share_cache(int this_cpu, int that_cpu);
1099
1100 typedef const struct cpumask *(*sched_domain_mask_f)(int cpu);
1101 typedef int (*sched_domain_flags_f)(void);
1102
1103 #define SDTL_OVERLAP 0x01
1104
1105 struct sd_data {
1106 struct sched_domain **__percpu sd;
1107 struct sched_group **__percpu sg;
1108 struct sched_group_capacity **__percpu sgc;
1109 };
1110
1111 struct sched_domain_topology_level {
1112 sched_domain_mask_f mask;
1113 sched_domain_flags_f sd_flags;
1114 int flags;
1115 int numa_level;
1116 struct sd_data data;
1117 #ifdef CONFIG_SCHED_DEBUG
1118 char *name;
1119 #endif
1120 };
1121
1122 extern struct sched_domain_topology_level *sched_domain_topology;
1123
1124 extern void set_sched_topology(struct sched_domain_topology_level *tl);
1125 extern void wake_up_if_idle(int cpu);
1126
1127 #ifdef CONFIG_SCHED_DEBUG
1128 # define SD_INIT_NAME(type) .name = #type
1129 #else
1130 # define SD_INIT_NAME(type)
1131 #endif
1132
1133 #else /* CONFIG_SMP */
1134
1135 struct sched_domain_attr;
1136
1137 static inline void
1138 partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1139 struct sched_domain_attr *dattr_new)
1140 {
1141 }
1142
1143 static inline bool cpus_share_cache(int this_cpu, int that_cpu)
1144 {
1145 return true;
1146 }
1147
1148 #endif /* !CONFIG_SMP */
1149
1150
1151 struct io_context; /* See blkdev.h */
1152
1153
1154 #ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
1155 extern void prefetch_stack(struct task_struct *t);
1156 #else
1157 static inline void prefetch_stack(struct task_struct *t) { }
1158 #endif
1159
1160 struct audit_context; /* See audit.c */
1161 struct mempolicy;
1162 struct pipe_inode_info;
1163 struct uts_namespace;
1164
1165 struct load_weight {
1166 unsigned long weight;
1167 u32 inv_weight;
1168 };
1169
1170 struct sched_avg {
1171 u64 last_runnable_update;
1172 s64 decay_count;
1173 /*
1174 * utilization_avg_contrib describes the amount of time that a
1175 * sched_entity is running on a CPU. It is based on running_avg_sum
1176 * and is scaled in the range [0..SCHED_LOAD_SCALE].
1177 * load_avg_contrib described the amount of time that a sched_entity
1178 * is runnable on a rq. It is based on both runnable_avg_sum and the
1179 * weight of the task.
1180 */
1181 unsigned long load_avg_contrib, utilization_avg_contrib;
1182 /*
1183 * These sums represent an infinite geometric series and so are bound
1184 * above by 1024/(1-y). Thus we only need a u32 to store them for all
1185 * choices of y < 1-2^(-32)*1024.
1186 * running_avg_sum reflects the time that the sched_entity is
1187 * effectively running on the CPU.
1188 * runnable_avg_sum represents the amount of time a sched_entity is on
1189 * a runqueue which includes the running time that is monitored by
1190 * running_avg_sum.
1191 */
1192 u32 runnable_avg_sum, avg_period, running_avg_sum;
1193 };
1194
1195 #ifdef CONFIG_SCHEDSTATS
1196 struct sched_statistics {
1197 u64 wait_start;
1198 u64 wait_max;
1199 u64 wait_count;
1200 u64 wait_sum;
1201 u64 iowait_count;
1202 u64 iowait_sum;
1203
1204 u64 sleep_start;
1205 u64 sleep_max;
1206 s64 sum_sleep_runtime;
1207
1208 u64 block_start;
1209 u64 block_max;
1210 u64 exec_max;
1211 u64 slice_max;
1212
1213 u64 nr_migrations_cold;
1214 u64 nr_failed_migrations_affine;
1215 u64 nr_failed_migrations_running;
1216 u64 nr_failed_migrations_hot;
1217 u64 nr_forced_migrations;
1218
1219 u64 nr_wakeups;
1220 u64 nr_wakeups_sync;
1221 u64 nr_wakeups_migrate;
1222 u64 nr_wakeups_local;
1223 u64 nr_wakeups_remote;
1224 u64 nr_wakeups_affine;
1225 u64 nr_wakeups_affine_attempts;
1226 u64 nr_wakeups_passive;
1227 u64 nr_wakeups_idle;
1228 };
1229 #endif
1230
1231 struct sched_entity {
1232 struct load_weight load; /* for load-balancing */
1233 struct rb_node run_node;
1234 struct list_head group_node;
1235 unsigned int on_rq;
1236
1237 u64 exec_start;
1238 u64 sum_exec_runtime;
1239 u64 vruntime;
1240 u64 prev_sum_exec_runtime;
1241
1242 u64 nr_migrations;
1243
1244 #ifdef CONFIG_SCHEDSTATS
1245 struct sched_statistics statistics;
1246 #endif
1247
1248 #ifdef CONFIG_FAIR_GROUP_SCHED
1249 int depth;
1250 struct sched_entity *parent;
1251 /* rq on which this entity is (to be) queued: */
1252 struct cfs_rq *cfs_rq;
1253 /* rq "owned" by this entity/group: */
1254 struct cfs_rq *my_q;
1255 #endif
1256
1257 #ifdef CONFIG_SMP
1258 /* Per-entity load-tracking */
1259 struct sched_avg avg;
1260 #endif
1261 };
1262
1263 struct sched_rt_entity {
1264 struct list_head run_list;
1265 unsigned long timeout;
1266 unsigned long watchdog_stamp;
1267 unsigned int time_slice;
1268
1269 struct sched_rt_entity *back;
1270 #ifdef CONFIG_RT_GROUP_SCHED
1271 struct sched_rt_entity *parent;
1272 /* rq on which this entity is (to be) queued: */
1273 struct rt_rq *rt_rq;
1274 /* rq "owned" by this entity/group: */
1275 struct rt_rq *my_q;
1276 #endif
1277 };
1278
1279 struct sched_dl_entity {
1280 struct rb_node rb_node;
1281
1282 /*
1283 * Original scheduling parameters. Copied here from sched_attr
1284 * during sched_setattr(), they will remain the same until
1285 * the next sched_setattr().
1286 */
1287 u64 dl_runtime; /* maximum runtime for each instance */
1288 u64 dl_deadline; /* relative deadline of each instance */
1289 u64 dl_period; /* separation of two instances (period) */
1290 u64 dl_bw; /* dl_runtime / dl_deadline */
1291
1292 /*
1293 * Actual scheduling parameters. Initialized with the values above,
1294 * they are continously updated during task execution. Note that
1295 * the remaining runtime could be < 0 in case we are in overrun.
1296 */
1297 s64 runtime; /* remaining runtime for this instance */
1298 u64 deadline; /* absolute deadline for this instance */
1299 unsigned int flags; /* specifying the scheduler behaviour */
1300
1301 /*
1302 * Some bool flags:
1303 *
1304 * @dl_throttled tells if we exhausted the runtime. If so, the
1305 * task has to wait for a replenishment to be performed at the
1306 * next firing of dl_timer.
1307 *
1308 * @dl_new tells if a new instance arrived. If so we must
1309 * start executing it with full runtime and reset its absolute
1310 * deadline;
1311 *
1312 * @dl_boosted tells if we are boosted due to DI. If so we are
1313 * outside bandwidth enforcement mechanism (but only until we
1314 * exit the critical section);
1315 *
1316 * @dl_yielded tells if task gave up the cpu before consuming
1317 * all its available runtime during the last job.
1318 */
1319 int dl_throttled, dl_new, dl_boosted, dl_yielded;
1320
1321 /*
1322 * Bandwidth enforcement timer. Each -deadline task has its
1323 * own bandwidth to be enforced, thus we need one timer per task.
1324 */
1325 struct hrtimer dl_timer;
1326 };
1327
1328 union rcu_special {
1329 struct {
1330 bool blocked;
1331 bool need_qs;
1332 } b;
1333 short s;
1334 };
1335 struct rcu_node;
1336
1337 enum perf_event_task_context {
1338 perf_invalid_context = -1,
1339 perf_hw_context = 0,
1340 perf_sw_context,
1341 perf_nr_task_contexts,
1342 };
1343
1344 struct task_struct {
1345 volatile long state; /* -1 unrunnable, 0 runnable, >0 stopped */
1346 void *stack;
1347 atomic_t usage;
1348 unsigned int flags; /* per process flags, defined below */
1349 unsigned int ptrace;
1350
1351 #ifdef CONFIG_SMP
1352 struct llist_node wake_entry;
1353 int on_cpu;
1354 struct task_struct *last_wakee;
1355 unsigned long wakee_flips;
1356 unsigned long wakee_flip_decay_ts;
1357
1358 int wake_cpu;
1359 #endif
1360 int on_rq;
1361
1362 int prio, static_prio, normal_prio;
1363 unsigned int rt_priority;
1364 const struct sched_class *sched_class;
1365 struct sched_entity se;
1366 struct sched_rt_entity rt;
1367 #ifdef CONFIG_CGROUP_SCHED
1368 struct task_group *sched_task_group;
1369 #endif
1370 struct sched_dl_entity dl;
1371
1372 #ifdef CONFIG_PREEMPT_NOTIFIERS
1373 /* list of struct preempt_notifier: */
1374 struct hlist_head preempt_notifiers;
1375 #endif
1376
1377 #ifdef CONFIG_BLK_DEV_IO_TRACE
1378 unsigned int btrace_seq;
1379 #endif
1380
1381 unsigned int policy;
1382 int nr_cpus_allowed;
1383 cpumask_t cpus_allowed;
1384
1385 #ifdef CONFIG_PREEMPT_RCU
1386 int rcu_read_lock_nesting;
1387 union rcu_special rcu_read_unlock_special;
1388 struct list_head rcu_node_entry;
1389 struct rcu_node *rcu_blocked_node;
1390 #endif /* #ifdef CONFIG_PREEMPT_RCU */
1391 #ifdef CONFIG_TASKS_RCU
1392 unsigned long rcu_tasks_nvcsw;
1393 bool rcu_tasks_holdout;
1394 struct list_head rcu_tasks_holdout_list;
1395 int rcu_tasks_idle_cpu;
1396 #endif /* #ifdef CONFIG_TASKS_RCU */
1397
1398 #ifdef CONFIG_SCHED_INFO
1399 struct sched_info sched_info;
1400 #endif
1401
1402 struct list_head tasks;
1403 #ifdef CONFIG_SMP
1404 struct plist_node pushable_tasks;
1405 struct rb_node pushable_dl_tasks;
1406 #endif
1407
1408 struct mm_struct *mm, *active_mm;
1409 /* per-thread vma caching */
1410 u32 vmacache_seqnum;
1411 struct vm_area_struct *vmacache[VMACACHE_SIZE];
1412 #if defined(SPLIT_RSS_COUNTING)
1413 struct task_rss_stat rss_stat;
1414 #endif
1415 /* task state */
1416 int exit_state;
1417 int exit_code, exit_signal;
1418 int pdeath_signal; /* The signal sent when the parent dies */
1419 unsigned long jobctl; /* JOBCTL_*, siglock protected */
1420
1421 /* Used for emulating ABI behavior of previous Linux versions */
1422 unsigned int personality;
1423
1424 unsigned in_execve:1; /* Tell the LSMs that the process is doing an
1425 * execve */
1426 unsigned in_iowait:1;
1427
1428 /* Revert to default priority/policy when forking */
1429 unsigned sched_reset_on_fork:1;
1430 unsigned sched_contributes_to_load:1;
1431 unsigned sched_migrated:1;
1432
1433 #ifdef CONFIG_MEMCG_KMEM
1434 unsigned memcg_kmem_skip_account:1;
1435 #endif
1436 #ifdef CONFIG_COMPAT_BRK
1437 unsigned brk_randomized:1;
1438 #endif
1439
1440 unsigned long atomic_flags; /* Flags needing atomic access. */
1441
1442 struct restart_block restart_block;
1443
1444 pid_t pid;
1445 pid_t tgid;
1446
1447 #ifdef CONFIG_CC_STACKPROTECTOR
1448 /* Canary value for the -fstack-protector gcc feature */
1449 unsigned long stack_canary;
1450 #endif
1451 /*
1452 * pointers to (original) parent process, youngest child, younger sibling,
1453 * older sibling, respectively. (p->father can be replaced with
1454 * p->real_parent->pid)
1455 */
1456 struct task_struct __rcu *real_parent; /* real parent process */
1457 struct task_struct __rcu *parent; /* recipient of SIGCHLD, wait4() reports */
1458 /*
1459 * children/sibling forms the list of my natural children
1460 */
1461 struct list_head children; /* list of my children */
1462 struct list_head sibling; /* linkage in my parent's children list */
1463 struct task_struct *group_leader; /* threadgroup leader */
1464
1465 /*
1466 * ptraced is the list of tasks this task is using ptrace on.
1467 * This includes both natural children and PTRACE_ATTACH targets.
1468 * p->ptrace_entry is p's link on the p->parent->ptraced list.
1469 */
1470 struct list_head ptraced;
1471 struct list_head ptrace_entry;
1472
1473 /* PID/PID hash table linkage. */
1474 struct pid_link pids[PIDTYPE_MAX];
1475 struct list_head thread_group;
1476 struct list_head thread_node;
1477
1478 struct completion *vfork_done; /* for vfork() */
1479 int __user *set_child_tid; /* CLONE_CHILD_SETTID */
1480 int __user *clear_child_tid; /* CLONE_CHILD_CLEARTID */
1481
1482 cputime_t utime, stime, utimescaled, stimescaled;
1483 cputime_t gtime;
1484 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
1485 struct cputime prev_cputime;
1486 #endif
1487 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1488 seqlock_t vtime_seqlock;
1489 unsigned long long vtime_snap;
1490 enum {
1491 VTIME_SLEEPING = 0,
1492 VTIME_USER,
1493 VTIME_SYS,
1494 } vtime_snap_whence;
1495 #endif
1496 unsigned long nvcsw, nivcsw; /* context switch counts */
1497 u64 start_time; /* monotonic time in nsec */
1498 u64 real_start_time; /* boot based time in nsec */
1499 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1500 unsigned long min_flt, maj_flt;
1501
1502 struct task_cputime cputime_expires;
1503 struct list_head cpu_timers[3];
1504
1505 /* process credentials */
1506 const struct cred __rcu *real_cred; /* objective and real subjective task
1507 * credentials (COW) */
1508 const struct cred __rcu *cred; /* effective (overridable) subjective task
1509 * credentials (COW) */
1510 char comm[TASK_COMM_LEN]; /* executable name excluding path
1511 - access with [gs]et_task_comm (which lock
1512 it with task_lock())
1513 - initialized normally by setup_new_exec */
1514 /* file system info */
1515 struct nameidata *nameidata;
1516 #ifdef CONFIG_SYSVIPC
1517 /* ipc stuff */
1518 struct sysv_sem sysvsem;
1519 struct sysv_shm sysvshm;
1520 #endif
1521 #ifdef CONFIG_DETECT_HUNG_TASK
1522 /* hung task detection */
1523 unsigned long last_switch_count;
1524 #endif
1525 /* filesystem information */
1526 struct fs_struct *fs;
1527 /* open file information */
1528 struct files_struct *files;
1529 /* namespaces */
1530 struct nsproxy *nsproxy;
1531 /* signal handlers */
1532 struct signal_struct *signal;
1533 struct sighand_struct *sighand;
1534
1535 sigset_t blocked, real_blocked;
1536 sigset_t saved_sigmask; /* restored if set_restore_sigmask() was used */
1537 struct sigpending pending;
1538
1539 unsigned long sas_ss_sp;
1540 size_t sas_ss_size;
1541 int (*notifier)(void *priv);
1542 void *notifier_data;
1543 sigset_t *notifier_mask;
1544 struct callback_head *task_works;
1545
1546 struct audit_context *audit_context;
1547 #ifdef CONFIG_AUDITSYSCALL
1548 kuid_t loginuid;
1549 unsigned int sessionid;
1550 #endif
1551 struct seccomp seccomp;
1552
1553 /* Thread group tracking */
1554 u32 parent_exec_id;
1555 u32 self_exec_id;
1556 /* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1557 * mempolicy */
1558 spinlock_t alloc_lock;
1559
1560 /* Protection of the PI data structures: */
1561 raw_spinlock_t pi_lock;
1562
1563 struct wake_q_node wake_q;
1564
1565 #ifdef CONFIG_RT_MUTEXES
1566 /* PI waiters blocked on a rt_mutex held by this task */
1567 struct rb_root pi_waiters;
1568 struct rb_node *pi_waiters_leftmost;
1569 /* Deadlock detection and priority inheritance handling */
1570 struct rt_mutex_waiter *pi_blocked_on;
1571 #endif
1572
1573 #ifdef CONFIG_DEBUG_MUTEXES
1574 /* mutex deadlock detection */
1575 struct mutex_waiter *blocked_on;
1576 #endif
1577 #ifdef CONFIG_TRACE_IRQFLAGS
1578 unsigned int irq_events;
1579 unsigned long hardirq_enable_ip;
1580 unsigned long hardirq_disable_ip;
1581 unsigned int hardirq_enable_event;
1582 unsigned int hardirq_disable_event;
1583 int hardirqs_enabled;
1584 int hardirq_context;
1585 unsigned long softirq_disable_ip;
1586 unsigned long softirq_enable_ip;
1587 unsigned int softirq_disable_event;
1588 unsigned int softirq_enable_event;
1589 int softirqs_enabled;
1590 int softirq_context;
1591 #endif
1592 #ifdef CONFIG_LOCKDEP
1593 # define MAX_LOCK_DEPTH 48UL
1594 u64 curr_chain_key;
1595 int lockdep_depth;
1596 unsigned int lockdep_recursion;
1597 struct held_lock held_locks[MAX_LOCK_DEPTH];
1598 gfp_t lockdep_reclaim_gfp;
1599 #endif
1600
1601 /* journalling filesystem info */
1602 void *journal_info;
1603
1604 /* stacked block device info */
1605 struct bio_list *bio_list;
1606
1607 #ifdef CONFIG_BLOCK
1608 /* stack plugging */
1609 struct blk_plug *plug;
1610 #endif
1611
1612 /* VM state */
1613 struct reclaim_state *reclaim_state;
1614
1615 struct backing_dev_info *backing_dev_info;
1616
1617 struct io_context *io_context;
1618
1619 unsigned long ptrace_message;
1620 siginfo_t *last_siginfo; /* For ptrace use. */
1621 struct task_io_accounting ioac;
1622 #if defined(CONFIG_TASK_XACCT)
1623 u64 acct_rss_mem1; /* accumulated rss usage */
1624 u64 acct_vm_mem1; /* accumulated virtual memory usage */
1625 cputime_t acct_timexpd; /* stime + utime since last update */
1626 #endif
1627 #ifdef CONFIG_CPUSETS
1628 nodemask_t mems_allowed; /* Protected by alloc_lock */
1629 seqcount_t mems_allowed_seq; /* Seqence no to catch updates */
1630 int cpuset_mem_spread_rotor;
1631 int cpuset_slab_spread_rotor;
1632 #endif
1633 #ifdef CONFIG_CGROUPS
1634 /* Control Group info protected by css_set_lock */
1635 struct css_set __rcu *cgroups;
1636 /* cg_list protected by css_set_lock and tsk->alloc_lock */
1637 struct list_head cg_list;
1638 #endif
1639 #ifdef CONFIG_FUTEX
1640 struct robust_list_head __user *robust_list;
1641 #ifdef CONFIG_COMPAT
1642 struct compat_robust_list_head __user *compat_robust_list;
1643 #endif
1644 struct list_head pi_state_list;
1645 struct futex_pi_state *pi_state_cache;
1646 #endif
1647 #ifdef CONFIG_PERF_EVENTS
1648 struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1649 struct mutex perf_event_mutex;
1650 struct list_head perf_event_list;
1651 #endif
1652 #ifdef CONFIG_DEBUG_PREEMPT
1653 unsigned long preempt_disable_ip;
1654 #endif
1655 #ifdef CONFIG_NUMA
1656 struct mempolicy *mempolicy; /* Protected by alloc_lock */
1657 short il_next;
1658 short pref_node_fork;
1659 #endif
1660 #ifdef CONFIG_NUMA_BALANCING
1661 int numa_scan_seq;
1662 unsigned int numa_scan_period;
1663 unsigned int numa_scan_period_max;
1664 int numa_preferred_nid;
1665 unsigned long numa_migrate_retry;
1666 u64 node_stamp; /* migration stamp */
1667 u64 last_task_numa_placement;
1668 u64 last_sum_exec_runtime;
1669 struct callback_head numa_work;
1670
1671 struct list_head numa_entry;
1672 struct numa_group *numa_group;
1673
1674 /*
1675 * numa_faults is an array split into four regions:
1676 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1677 * in this precise order.
1678 *
1679 * faults_memory: Exponential decaying average of faults on a per-node
1680 * basis. Scheduling placement decisions are made based on these
1681 * counts. The values remain static for the duration of a PTE scan.
1682 * faults_cpu: Track the nodes the process was running on when a NUMA
1683 * hinting fault was incurred.
1684 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1685 * during the current scan window. When the scan completes, the counts
1686 * in faults_memory and faults_cpu decay and these values are copied.
1687 */
1688 unsigned long *numa_faults;
1689 unsigned long total_numa_faults;
1690
1691 /*
1692 * numa_faults_locality tracks if faults recorded during the last
1693 * scan window were remote/local or failed to migrate. The task scan
1694 * period is adapted based on the locality of the faults with different
1695 * weights depending on whether they were shared or private faults
1696 */
1697 unsigned long numa_faults_locality[3];
1698
1699 unsigned long numa_pages_migrated;
1700 #endif /* CONFIG_NUMA_BALANCING */
1701
1702 struct rcu_head rcu;
1703
1704 /*
1705 * cache last used pipe for splice
1706 */
1707 struct pipe_inode_info *splice_pipe;
1708
1709 struct page_frag task_frag;
1710
1711 #ifdef CONFIG_TASK_DELAY_ACCT
1712 struct task_delay_info *delays;
1713 #endif
1714 #ifdef CONFIG_FAULT_INJECTION
1715 int make_it_fail;
1716 #endif
1717 /*
1718 * when (nr_dirtied >= nr_dirtied_pause), it's time to call
1719 * balance_dirty_pages() for some dirty throttling pause
1720 */
1721 int nr_dirtied;
1722 int nr_dirtied_pause;
1723 unsigned long dirty_paused_when; /* start of a write-and-pause period */
1724
1725 #ifdef CONFIG_LATENCYTOP
1726 int latency_record_count;
1727 struct latency_record latency_record[LT_SAVECOUNT];
1728 #endif
1729 /*
1730 * time slack values; these are used to round up poll() and
1731 * select() etc timeout values. These are in nanoseconds.
1732 */
1733 unsigned long timer_slack_ns;
1734 unsigned long default_timer_slack_ns;
1735
1736 #ifdef CONFIG_KASAN
1737 unsigned int kasan_depth;
1738 #endif
1739 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1740 /* Index of current stored address in ret_stack */
1741 int curr_ret_stack;
1742 /* Stack of return addresses for return function tracing */
1743 struct ftrace_ret_stack *ret_stack;
1744 /* time stamp for last schedule */
1745 unsigned long long ftrace_timestamp;
1746 /*
1747 * Number of functions that haven't been traced
1748 * because of depth overrun.
1749 */
1750 atomic_t trace_overrun;
1751 /* Pause for the tracing */
1752 atomic_t tracing_graph_pause;
1753 #endif
1754 #ifdef CONFIG_TRACING
1755 /* state flags for use by tracers */
1756 unsigned long trace;
1757 /* bitmask and counter of trace recursion */
1758 unsigned long trace_recursion;
1759 #endif /* CONFIG_TRACING */
1760 #ifdef CONFIG_MEMCG
1761 struct memcg_oom_info {
1762 struct mem_cgroup *memcg;
1763 gfp_t gfp_mask;
1764 int order;
1765 unsigned int may_oom:1;
1766 } memcg_oom;
1767 #endif
1768 #ifdef CONFIG_UPROBES
1769 struct uprobe_task *utask;
1770 #endif
1771 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1772 unsigned int sequential_io;
1773 unsigned int sequential_io_avg;
1774 #endif
1775 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1776 unsigned long task_state_change;
1777 #endif
1778 int pagefault_disabled;
1779 /* CPU-specific state of this task */
1780 struct thread_struct thread;
1781 /*
1782 * WARNING: on x86, 'thread_struct' contains a variable-sized
1783 * structure. It *MUST* be at the end of 'task_struct'.
1784 *
1785 * Do not put anything below here!
1786 */
1787 };
1788
1789 #ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
1790 extern int arch_task_struct_size __read_mostly;
1791 #else
1792 # define arch_task_struct_size (sizeof(struct task_struct))
1793 #endif
1794
1795 /* Future-safe accessor for struct task_struct's cpus_allowed. */
1796 #define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
1797
1798 #define TNF_MIGRATED 0x01
1799 #define TNF_NO_GROUP 0x02
1800 #define TNF_SHARED 0x04
1801 #define TNF_FAULT_LOCAL 0x08
1802 #define TNF_MIGRATE_FAIL 0x10
1803
1804 #ifdef CONFIG_NUMA_BALANCING
1805 extern void task_numa_fault(int last_node, int node, int pages, int flags);
1806 extern pid_t task_numa_group_id(struct task_struct *p);
1807 extern void set_numabalancing_state(bool enabled);
1808 extern void task_numa_free(struct task_struct *p);
1809 extern bool should_numa_migrate_memory(struct task_struct *p, struct page *page,
1810 int src_nid, int dst_cpu);
1811 #else
1812 static inline void task_numa_fault(int last_node, int node, int pages,
1813 int flags)
1814 {
1815 }
1816 static inline pid_t task_numa_group_id(struct task_struct *p)
1817 {
1818 return 0;
1819 }
1820 static inline void set_numabalancing_state(bool enabled)
1821 {
1822 }
1823 static inline void task_numa_free(struct task_struct *p)
1824 {
1825 }
1826 static inline bool should_numa_migrate_memory(struct task_struct *p,
1827 struct page *page, int src_nid, int dst_cpu)
1828 {
1829 return true;
1830 }
1831 #endif
1832
1833 static inline struct pid *task_pid(struct task_struct *task)
1834 {
1835 return task->pids[PIDTYPE_PID].pid;
1836 }
1837
1838 static inline struct pid *task_tgid(struct task_struct *task)
1839 {
1840 return task->group_leader->pids[PIDTYPE_PID].pid;
1841 }
1842
1843 /*
1844 * Without tasklist or rcu lock it is not safe to dereference
1845 * the result of task_pgrp/task_session even if task == current,
1846 * we can race with another thread doing sys_setsid/sys_setpgid.
1847 */
1848 static inline struct pid *task_pgrp(struct task_struct *task)
1849 {
1850 return task->group_leader->pids[PIDTYPE_PGID].pid;
1851 }
1852
1853 static inline struct pid *task_session(struct task_struct *task)
1854 {
1855 return task->group_leader->pids[PIDTYPE_SID].pid;
1856 }
1857
1858 struct pid_namespace;
1859
1860 /*
1861 * the helpers to get the task's different pids as they are seen
1862 * from various namespaces
1863 *
1864 * task_xid_nr() : global id, i.e. the id seen from the init namespace;
1865 * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of
1866 * current.
1867 * task_xid_nr_ns() : id seen from the ns specified;
1868 *
1869 * set_task_vxid() : assigns a virtual id to a task;
1870 *
1871 * see also pid_nr() etc in include/linux/pid.h
1872 */
1873 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
1874 struct pid_namespace *ns);
1875
1876 static inline pid_t task_pid_nr(struct task_struct *tsk)
1877 {
1878 return tsk->pid;
1879 }
1880
1881 static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
1882 struct pid_namespace *ns)
1883 {
1884 return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1885 }
1886
1887 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1888 {
1889 return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1890 }
1891
1892
1893 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1894 {
1895 return tsk->tgid;
1896 }
1897
1898 pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1899
1900 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1901 {
1902 return pid_vnr(task_tgid(tsk));
1903 }
1904
1905
1906 static inline int pid_alive(const struct task_struct *p);
1907 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1908 {
1909 pid_t pid = 0;
1910
1911 rcu_read_lock();
1912 if (pid_alive(tsk))
1913 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1914 rcu_read_unlock();
1915
1916 return pid;
1917 }
1918
1919 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1920 {
1921 return task_ppid_nr_ns(tsk, &init_pid_ns);
1922 }
1923
1924 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
1925 struct pid_namespace *ns)
1926 {
1927 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1928 }
1929
1930 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1931 {
1932 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1933 }
1934
1935
1936 static inline pid_t task_session_nr_ns(struct task_struct *tsk,
1937 struct pid_namespace *ns)
1938 {
1939 return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1940 }
1941
1942 static inline pid_t task_session_vnr(struct task_struct *tsk)
1943 {
1944 return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1945 }
1946
1947 /* obsolete, do not use */
1948 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1949 {
1950 return task_pgrp_nr_ns(tsk, &init_pid_ns);
1951 }
1952
1953 /**
1954 * pid_alive - check that a task structure is not stale
1955 * @p: Task structure to be checked.
1956 *
1957 * Test if a process is not yet dead (at most zombie state)
1958 * If pid_alive fails, then pointers within the task structure
1959 * can be stale and must not be dereferenced.
1960 *
1961 * Return: 1 if the process is alive. 0 otherwise.
1962 */
1963 static inline int pid_alive(const struct task_struct *p)
1964 {
1965 return p->pids[PIDTYPE_PID].pid != NULL;
1966 }
1967
1968 /**
1969 * is_global_init - check if a task structure is init
1970 * @tsk: Task structure to be checked.
1971 *
1972 * Check if a task structure is the first user space task the kernel created.
1973 *
1974 * Return: 1 if the task structure is init. 0 otherwise.
1975 */
1976 static inline int is_global_init(struct task_struct *tsk)
1977 {
1978 return tsk->pid == 1;
1979 }
1980
1981 extern struct pid *cad_pid;
1982
1983 extern void free_task(struct task_struct *tsk);
1984 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
1985
1986 extern void __put_task_struct(struct task_struct *t);
1987
1988 static inline void put_task_struct(struct task_struct *t)
1989 {
1990 if (atomic_dec_and_test(&t->usage))
1991 __put_task_struct(t);
1992 }
1993
1994 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
1995 extern void task_cputime(struct task_struct *t,
1996 cputime_t *utime, cputime_t *stime);
1997 extern void task_cputime_scaled(struct task_struct *t,
1998 cputime_t *utimescaled, cputime_t *stimescaled);
1999 extern cputime_t task_gtime(struct task_struct *t);
2000 #else
2001 static inline void task_cputime(struct task_struct *t,
2002 cputime_t *utime, cputime_t *stime)
2003 {
2004 if (utime)
2005 *utime = t->utime;
2006 if (stime)
2007 *stime = t->stime;
2008 }
2009
2010 static inline void task_cputime_scaled(struct task_struct *t,
2011 cputime_t *utimescaled,
2012 cputime_t *stimescaled)
2013 {
2014 if (utimescaled)
2015 *utimescaled = t->utimescaled;
2016 if (stimescaled)
2017 *stimescaled = t->stimescaled;
2018 }
2019
2020 static inline cputime_t task_gtime(struct task_struct *t)
2021 {
2022 return t->gtime;
2023 }
2024 #endif
2025 extern void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
2026 extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
2027
2028 /*
2029 * Per process flags
2030 */
2031 #define PF_EXITING 0x00000004 /* getting shut down */
2032 #define PF_EXITPIDONE 0x00000008 /* pi exit done on shut down */
2033 #define PF_VCPU 0x00000010 /* I'm a virtual CPU */
2034 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */
2035 #define PF_FORKNOEXEC 0x00000040 /* forked but didn't exec */
2036 #define PF_MCE_PROCESS 0x00000080 /* process policy on mce errors */
2037 #define PF_SUPERPRIV 0x00000100 /* used super-user privileges */
2038 #define PF_DUMPCORE 0x00000200 /* dumped core */
2039 #define PF_SIGNALED 0x00000400 /* killed by a signal */
2040 #define PF_MEMALLOC 0x00000800 /* Allocating memory */
2041 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user noticed that RLIMIT_NPROC was exceeded */
2042 #define PF_USED_MATH 0x00002000 /* if unset the fpu must be initialized before use */
2043 #define PF_USED_ASYNC 0x00004000 /* used async_schedule*(), used by module init */
2044 #define PF_NOFREEZE 0x00008000 /* this thread should not be frozen */
2045 #define PF_FROZEN 0x00010000 /* frozen for system suspend */
2046 #define PF_FSTRANS 0x00020000 /* inside a filesystem transaction */
2047 #define PF_KSWAPD 0x00040000 /* I am kswapd */
2048 #define PF_MEMALLOC_NOIO 0x00080000 /* Allocating memory without IO involved */
2049 #define PF_LESS_THROTTLE 0x00100000 /* Throttle me less: I clean memory */
2050 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */
2051 #define PF_RANDOMIZE 0x00400000 /* randomize virtual address space */
2052 #define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */
2053 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_allowed */
2054 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */
2055 #define PF_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */
2056 #define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezable */
2057 #define PF_SUSPEND_TASK 0x80000000 /* this thread called freeze_processes and should not be frozen */
2058
2059 /*
2060 * Only the _current_ task can read/write to tsk->flags, but other
2061 * tasks can access tsk->flags in readonly mode for example
2062 * with tsk_used_math (like during threaded core dumping).
2063 * There is however an exception to this rule during ptrace
2064 * or during fork: the ptracer task is allowed to write to the
2065 * child->flags of its traced child (same goes for fork, the parent
2066 * can write to the child->flags), because we're guaranteed the
2067 * child is not running and in turn not changing child->flags
2068 * at the same time the parent does it.
2069 */
2070 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
2071 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
2072 #define clear_used_math() clear_stopped_child_used_math(current)
2073 #define set_used_math() set_stopped_child_used_math(current)
2074 #define conditional_stopped_child_used_math(condition, child) \
2075 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
2076 #define conditional_used_math(condition) \
2077 conditional_stopped_child_used_math(condition, current)
2078 #define copy_to_stopped_child_used_math(child) \
2079 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
2080 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
2081 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
2082 #define used_math() tsk_used_math(current)
2083
2084 /* __GFP_IO isn't allowed if PF_MEMALLOC_NOIO is set in current->flags
2085 * __GFP_FS is also cleared as it implies __GFP_IO.
2086 */
2087 static inline gfp_t memalloc_noio_flags(gfp_t flags)
2088 {
2089 if (unlikely(current->flags & PF_MEMALLOC_NOIO))
2090 flags &= ~(__GFP_IO | __GFP_FS);
2091 return flags;
2092 }
2093
2094 static inline unsigned int memalloc_noio_save(void)
2095 {
2096 unsigned int flags = current->flags & PF_MEMALLOC_NOIO;
2097 current->flags |= PF_MEMALLOC_NOIO;
2098 return flags;
2099 }
2100
2101 static inline void memalloc_noio_restore(unsigned int flags)
2102 {
2103 current->flags = (current->flags & ~PF_MEMALLOC_NOIO) | flags;
2104 }
2105
2106 /* Per-process atomic flags. */
2107 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */
2108 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */
2109 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */
2110
2111
2112 #define TASK_PFA_TEST(name, func) \
2113 static inline bool task_##func(struct task_struct *p) \
2114 { return test_bit(PFA_##name, &p->atomic_flags); }
2115 #define TASK_PFA_SET(name, func) \
2116 static inline void task_set_##func(struct task_struct *p) \
2117 { set_bit(PFA_##name, &p->atomic_flags); }
2118 #define TASK_PFA_CLEAR(name, func) \
2119 static inline void task_clear_##func(struct task_struct *p) \
2120 { clear_bit(PFA_##name, &p->atomic_flags); }
2121
2122 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
2123 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
2124
2125 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
2126 TASK_PFA_SET(SPREAD_PAGE, spread_page)
2127 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
2128
2129 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
2130 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
2131 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
2132
2133 /*
2134 * task->jobctl flags
2135 */
2136 #define JOBCTL_STOP_SIGMASK 0xffff /* signr of the last group stop */
2137
2138 #define JOBCTL_STOP_DEQUEUED_BIT 16 /* stop signal dequeued */
2139 #define JOBCTL_STOP_PENDING_BIT 17 /* task should stop for group stop */
2140 #define JOBCTL_STOP_CONSUME_BIT 18 /* consume group stop count */
2141 #define JOBCTL_TRAP_STOP_BIT 19 /* trap for STOP */
2142 #define JOBCTL_TRAP_NOTIFY_BIT 20 /* trap for NOTIFY */
2143 #define JOBCTL_TRAPPING_BIT 21 /* switching to TRACED */
2144 #define JOBCTL_LISTENING_BIT 22 /* ptracer is listening for events */
2145
2146 #define JOBCTL_STOP_DEQUEUED (1UL << JOBCTL_STOP_DEQUEUED_BIT)
2147 #define JOBCTL_STOP_PENDING (1UL << JOBCTL_STOP_PENDING_BIT)
2148 #define JOBCTL_STOP_CONSUME (1UL << JOBCTL_STOP_CONSUME_BIT)
2149 #define JOBCTL_TRAP_STOP (1UL << JOBCTL_TRAP_STOP_BIT)
2150 #define JOBCTL_TRAP_NOTIFY (1UL << JOBCTL_TRAP_NOTIFY_BIT)
2151 #define JOBCTL_TRAPPING (1UL << JOBCTL_TRAPPING_BIT)
2152 #define JOBCTL_LISTENING (1UL << JOBCTL_LISTENING_BIT)
2153
2154 #define JOBCTL_TRAP_MASK (JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
2155 #define JOBCTL_PENDING_MASK (JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)
2156
2157 extern bool task_set_jobctl_pending(struct task_struct *task,
2158 unsigned long mask);
2159 extern void task_clear_jobctl_trapping(struct task_struct *task);
2160 extern void task_clear_jobctl_pending(struct task_struct *task,
2161 unsigned long mask);
2162
2163 static inline void rcu_copy_process(struct task_struct *p)
2164 {
2165 #ifdef CONFIG_PREEMPT_RCU
2166 p->rcu_read_lock_nesting = 0;
2167 p->rcu_read_unlock_special.s = 0;
2168 p->rcu_blocked_node = NULL;
2169 INIT_LIST_HEAD(&p->rcu_node_entry);
2170 #endif /* #ifdef CONFIG_PREEMPT_RCU */
2171 #ifdef CONFIG_TASKS_RCU
2172 p->rcu_tasks_holdout = false;
2173 INIT_LIST_HEAD(&p->rcu_tasks_holdout_list);
2174 p->rcu_tasks_idle_cpu = -1;
2175 #endif /* #ifdef CONFIG_TASKS_RCU */
2176 }
2177
2178 static inline void tsk_restore_flags(struct task_struct *task,
2179 unsigned long orig_flags, unsigned long flags)
2180 {
2181 task->flags &= ~flags;
2182 task->flags |= orig_flags & flags;
2183 }
2184
2185 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur,
2186 const struct cpumask *trial);
2187 extern int task_can_attach(struct task_struct *p,
2188 const struct cpumask *cs_cpus_allowed);
2189 #ifdef CONFIG_SMP
2190 extern void do_set_cpus_allowed(struct task_struct *p,
2191 const struct cpumask *new_mask);
2192
2193 extern int set_cpus_allowed_ptr(struct task_struct *p,
2194 const struct cpumask *new_mask);
2195 #else
2196 static inline void do_set_cpus_allowed(struct task_struct *p,
2197 const struct cpumask *new_mask)
2198 {
2199 }
2200 static inline int set_cpus_allowed_ptr(struct task_struct *p,
2201 const struct cpumask *new_mask)
2202 {
2203 if (!cpumask_test_cpu(0, new_mask))
2204 return -EINVAL;
2205 return 0;
2206 }
2207 #endif
2208
2209 #ifdef CONFIG_NO_HZ_COMMON
2210 void calc_load_enter_idle(void);
2211 void calc_load_exit_idle(void);
2212 #else
2213 static inline void calc_load_enter_idle(void) { }
2214 static inline void calc_load_exit_idle(void) { }
2215 #endif /* CONFIG_NO_HZ_COMMON */
2216
2217 #ifndef CONFIG_CPUMASK_OFFSTACK
2218 static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
2219 {
2220 return set_cpus_allowed_ptr(p, &new_mask);
2221 }
2222 #endif
2223
2224 /*
2225 * Do not use outside of architecture code which knows its limitations.
2226 *
2227 * sched_clock() has no promise of monotonicity or bounded drift between
2228 * CPUs, use (which you should not) requires disabling IRQs.
2229 *
2230 * Please use one of the three interfaces below.
2231 */
2232 extern unsigned long long notrace sched_clock(void);
2233 /*
2234 * See the comment in kernel/sched/clock.c
2235 */
2236 extern u64 cpu_clock(int cpu);
2237 extern u64 local_clock(void);
2238 extern u64 running_clock(void);
2239 extern u64 sched_clock_cpu(int cpu);
2240
2241
2242 extern void sched_clock_init(void);
2243
2244 #ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
2245 static inline void sched_clock_tick(void)
2246 {
2247 }
2248
2249 static inline void sched_clock_idle_sleep_event(void)
2250 {
2251 }
2252
2253 static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
2254 {
2255 }
2256 #else
2257 /*
2258 * Architectures can set this to 1 if they have specified
2259 * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
2260 * but then during bootup it turns out that sched_clock()
2261 * is reliable after all:
2262 */
2263 extern int sched_clock_stable(void);
2264 extern void set_sched_clock_stable(void);
2265 extern void clear_sched_clock_stable(void);
2266
2267 extern void sched_clock_tick(void);
2268 extern void sched_clock_idle_sleep_event(void);
2269 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2270 #endif
2271
2272 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
2273 /*
2274 * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
2275 * The reason for this explicit opt-in is not to have perf penalty with
2276 * slow sched_clocks.
2277 */
2278 extern void enable_sched_clock_irqtime(void);
2279 extern void disable_sched_clock_irqtime(void);
2280 #else
2281 static inline void enable_sched_clock_irqtime(void) {}
2282 static inline void disable_sched_clock_irqtime(void) {}
2283 #endif
2284
2285 extern unsigned long long
2286 task_sched_runtime(struct task_struct *task);
2287
2288 /* sched_exec is called by processes performing an exec */
2289 #ifdef CONFIG_SMP
2290 extern void sched_exec(void);
2291 #else
2292 #define sched_exec() {}
2293 #endif
2294
2295 extern void sched_clock_idle_sleep_event(void);
2296 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2297
2298 #ifdef CONFIG_HOTPLUG_CPU
2299 extern void idle_task_exit(void);
2300 #else
2301 static inline void idle_task_exit(void) {}
2302 #endif
2303
2304 #if defined(CONFIG_NO_HZ_COMMON) && defined(CONFIG_SMP)
2305 extern void wake_up_nohz_cpu(int cpu);
2306 #else
2307 static inline void wake_up_nohz_cpu(int cpu) { }
2308 #endif
2309
2310 #ifdef CONFIG_NO_HZ_FULL
2311 extern bool sched_can_stop_tick(void);
2312 extern u64 scheduler_tick_max_deferment(void);
2313 #else
2314 static inline bool sched_can_stop_tick(void) { return false; }
2315 #endif
2316
2317 #ifdef CONFIG_SCHED_AUTOGROUP
2318 extern void sched_autogroup_create_attach(struct task_struct *p);
2319 extern void sched_autogroup_detach(struct task_struct *p);
2320 extern void sched_autogroup_fork(struct signal_struct *sig);
2321 extern void sched_autogroup_exit(struct signal_struct *sig);
2322 #ifdef CONFIG_PROC_FS
2323 extern void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m);
2324 extern int proc_sched_autogroup_set_nice(struct task_struct *p, int nice);
2325 #endif
2326 #else
2327 static inline void sched_autogroup_create_attach(struct task_struct *p) { }
2328 static inline void sched_autogroup_detach(struct task_struct *p) { }
2329 static inline void sched_autogroup_fork(struct signal_struct *sig) { }
2330 static inline void sched_autogroup_exit(struct signal_struct *sig) { }
2331 #endif
2332
2333 extern int yield_to(struct task_struct *p, bool preempt);
2334 extern void set_user_nice(struct task_struct *p, long nice);
2335 extern int task_prio(const struct task_struct *p);
2336 /**
2337 * task_nice - return the nice value of a given task.
2338 * @p: the task in question.
2339 *
2340 * Return: The nice value [ -20 ... 0 ... 19 ].
2341 */
2342 static inline int task_nice(const struct task_struct *p)
2343 {
2344 return PRIO_TO_NICE((p)->static_prio);
2345 }
2346 extern int can_nice(const struct task_struct *p, const int nice);
2347 extern int task_curr(const struct task_struct *p);
2348 extern int idle_cpu(int cpu);
2349 extern int sched_setscheduler(struct task_struct *, int,
2350 const struct sched_param *);
2351 extern int sched_setscheduler_nocheck(struct task_struct *, int,
2352 const struct sched_param *);
2353 extern int sched_setattr(struct task_struct *,
2354 const struct sched_attr *);
2355 extern struct task_struct *idle_task(int cpu);
2356 /**
2357 * is_idle_task - is the specified task an idle task?
2358 * @p: the task in question.
2359 *
2360 * Return: 1 if @p is an idle task. 0 otherwise.
2361 */
2362 static inline bool is_idle_task(const struct task_struct *p)
2363 {
2364 return p->pid == 0;
2365 }
2366 extern struct task_struct *curr_task(int cpu);
2367 extern void set_curr_task(int cpu, struct task_struct *p);
2368
2369 void yield(void);
2370
2371 union thread_union {
2372 struct thread_info thread_info;
2373 unsigned long stack[THREAD_SIZE/sizeof(long)];
2374 };
2375
2376 #ifndef __HAVE_ARCH_KSTACK_END
2377 static inline int kstack_end(void *addr)
2378 {
2379 /* Reliable end of stack detection:
2380 * Some APM bios versions misalign the stack
2381 */
2382 return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
2383 }
2384 #endif
2385
2386 extern union thread_union init_thread_union;
2387 extern struct task_struct init_task;
2388
2389 extern struct mm_struct init_mm;
2390
2391 extern struct pid_namespace init_pid_ns;
2392
2393 /*
2394 * find a task by one of its numerical ids
2395 *
2396 * find_task_by_pid_ns():
2397 * finds a task by its pid in the specified namespace
2398 * find_task_by_vpid():
2399 * finds a task by its virtual pid
2400 *
2401 * see also find_vpid() etc in include/linux/pid.h
2402 */
2403
2404 extern struct task_struct *find_task_by_vpid(pid_t nr);
2405 extern struct task_struct *find_task_by_pid_ns(pid_t nr,
2406 struct pid_namespace *ns);
2407
2408 /* per-UID process charging. */
2409 extern struct user_struct * alloc_uid(kuid_t);
2410 static inline struct user_struct *get_uid(struct user_struct *u)
2411 {
2412 atomic_inc(&u->__count);
2413 return u;
2414 }
2415 extern void free_uid(struct user_struct *);
2416
2417 #include <asm/current.h>
2418
2419 extern void xtime_update(unsigned long ticks);
2420
2421 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2422 extern int wake_up_process(struct task_struct *tsk);
2423 extern void wake_up_new_task(struct task_struct *tsk);
2424 #ifdef CONFIG_SMP
2425 extern void kick_process(struct task_struct *tsk);
2426 #else
2427 static inline void kick_process(struct task_struct *tsk) { }
2428 #endif
2429 extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
2430 extern void sched_dead(struct task_struct *p);
2431
2432 extern void proc_caches_init(void);
2433 extern void flush_signals(struct task_struct *);
2434 extern void ignore_signals(struct task_struct *);
2435 extern void flush_signal_handlers(struct task_struct *, int force_default);
2436 extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
2437
2438 static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
2439 {
2440 unsigned long flags;
2441 int ret;
2442
2443 spin_lock_irqsave(&tsk->sighand->siglock, flags);
2444 ret = dequeue_signal(tsk, mask, info);
2445 spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
2446
2447 return ret;
2448 }
2449
2450 extern void block_all_signals(int (*notifier)(void *priv), void *priv,
2451 sigset_t *mask);
2452 extern void unblock_all_signals(void);
2453 extern void release_task(struct task_struct * p);
2454 extern int send_sig_info(int, struct siginfo *, struct task_struct *);
2455 extern int force_sigsegv(int, struct task_struct *);
2456 extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2457 extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
2458 extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2459 extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *,
2460 const struct cred *, u32);
2461 extern int kill_pgrp(struct pid *pid, int sig, int priv);
2462 extern int kill_pid(struct pid *pid, int sig, int priv);
2463 extern int kill_proc_info(int, struct siginfo *, pid_t);
2464 extern __must_check bool do_notify_parent(struct task_struct *, int);
2465 extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
2466 extern void force_sig(int, struct task_struct *);
2467 extern int send_sig(int, struct task_struct *, int);
2468 extern int zap_other_threads(struct task_struct *p);
2469 extern struct sigqueue *sigqueue_alloc(void);
2470 extern void sigqueue_free(struct sigqueue *);
2471 extern int send_sigqueue(struct sigqueue *, struct task_struct *, int group);
2472 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
2473
2474 static inline void restore_saved_sigmask(void)
2475 {
2476 if (test_and_clear_restore_sigmask())
2477 __set_current_blocked(&current->saved_sigmask);
2478 }
2479
2480 static inline sigset_t *sigmask_to_save(void)
2481 {
2482 sigset_t *res = &current->blocked;
2483 if (unlikely(test_restore_sigmask()))
2484 res = &current->saved_sigmask;
2485 return res;
2486 }
2487
2488 static inline int kill_cad_pid(int sig, int priv)
2489 {
2490 return kill_pid(cad_pid, sig, priv);
2491 }
2492
2493 /* These can be the second arg to send_sig_info/send_group_sig_info. */
2494 #define SEND_SIG_NOINFO ((struct siginfo *) 0)
2495 #define SEND_SIG_PRIV ((struct siginfo *) 1)
2496 #define SEND_SIG_FORCED ((struct siginfo *) 2)
2497
2498 /*
2499 * True if we are on the alternate signal stack.
2500 */
2501 static inline int on_sig_stack(unsigned long sp)
2502 {
2503 #ifdef CONFIG_STACK_GROWSUP
2504 return sp >= current->sas_ss_sp &&
2505 sp - current->sas_ss_sp < current->sas_ss_size;
2506 #else
2507 return sp > current->sas_ss_sp &&
2508 sp - current->sas_ss_sp <= current->sas_ss_size;
2509 #endif
2510 }
2511
2512 static inline int sas_ss_flags(unsigned long sp)
2513 {
2514 if (!current->sas_ss_size)
2515 return SS_DISABLE;
2516
2517 return on_sig_stack(sp) ? SS_ONSTACK : 0;
2518 }
2519
2520 static inline unsigned long sigsp(unsigned long sp, struct ksignal *ksig)
2521 {
2522 if (unlikely((ksig->ka.sa.sa_flags & SA_ONSTACK)) && ! sas_ss_flags(sp))
2523 #ifdef CONFIG_STACK_GROWSUP
2524 return current->sas_ss_sp;
2525 #else
2526 return current->sas_ss_sp + current->sas_ss_size;
2527 #endif
2528 return sp;
2529 }
2530
2531 /*
2532 * Routines for handling mm_structs
2533 */
2534 extern struct mm_struct * mm_alloc(void);
2535
2536 /* mmdrop drops the mm and the page tables */
2537 extern void __mmdrop(struct mm_struct *);
2538 static inline void mmdrop(struct mm_struct * mm)
2539 {
2540 if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2541 __mmdrop(mm);
2542 }
2543
2544 /* mmput gets rid of the mappings and all user-space */
2545 extern void mmput(struct mm_struct *);
2546 /* Grab a reference to a task's mm, if it is not already going away */
2547 extern struct mm_struct *get_task_mm(struct task_struct *task);
2548 /*
2549 * Grab a reference to a task's mm, if it is not already going away
2550 * and ptrace_may_access with the mode parameter passed to it
2551 * succeeds.
2552 */
2553 extern struct mm_struct *mm_access(struct task_struct *task, unsigned int mode);
2554 /* Remove the current tasks stale references to the old mm_struct */
2555 extern void mm_release(struct task_struct *, struct mm_struct *);
2556
2557 #ifdef CONFIG_HAVE_COPY_THREAD_TLS
2558 extern int copy_thread_tls(unsigned long, unsigned long, unsigned long,
2559 struct task_struct *, unsigned long);
2560 #else
2561 extern int copy_thread(unsigned long, unsigned long, unsigned long,
2562 struct task_struct *);
2563
2564 /* Architectures that haven't opted into copy_thread_tls get the tls argument
2565 * via pt_regs, so ignore the tls argument passed via C. */
2566 static inline int copy_thread_tls(
2567 unsigned long clone_flags, unsigned long sp, unsigned long arg,
2568 struct task_struct *p, unsigned long tls)
2569 {
2570 return copy_thread(clone_flags, sp, arg, p);
2571 }
2572 #endif
2573 extern void flush_thread(void);
2574 extern void exit_thread(void);
2575
2576 extern void exit_files(struct task_struct *);
2577 extern void __cleanup_sighand(struct sighand_struct *);
2578
2579 extern void exit_itimers(struct signal_struct *);
2580 extern void flush_itimer_signals(void);
2581
2582 extern void do_group_exit(int);
2583
2584 extern int do_execve(struct filename *,
2585 const char __user * const __user *,
2586 const char __user * const __user *);
2587 extern int do_execveat(int, struct filename *,
2588 const char __user * const __user *,
2589 const char __user * const __user *,
2590 int);
2591 extern long _do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *, unsigned long);
2592 extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
2593 struct task_struct *fork_idle(int);
2594 extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
2595
2596 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
2597 static inline void set_task_comm(struct task_struct *tsk, const char *from)
2598 {
2599 __set_task_comm(tsk, from, false);
2600 }
2601 extern char *get_task_comm(char *to, struct task_struct *tsk);
2602
2603 #ifdef CONFIG_SMP
2604 void scheduler_ipi(void);
2605 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
2606 #else
2607 static inline void scheduler_ipi(void) { }
2608 static inline unsigned long wait_task_inactive(struct task_struct *p,
2609 long match_state)
2610 {
2611 return 1;
2612 }
2613 #endif
2614
2615 #define tasklist_empty() \
2616 list_empty(&init_task.tasks)
2617
2618 #define next_task(p) \
2619 list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
2620
2621 #define for_each_process(p) \
2622 for (p = &init_task ; (p = next_task(p)) != &init_task ; )
2623
2624 extern bool current_is_single_threaded(void);
2625
2626 /*
2627 * Careful: do_each_thread/while_each_thread is a double loop so
2628 * 'break' will not work as expected - use goto instead.
2629 */
2630 #define do_each_thread(g, t) \
2631 for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
2632
2633 #define while_each_thread(g, t) \
2634 while ((t = next_thread(t)) != g)
2635
2636 #define __for_each_thread(signal, t) \
2637 list_for_each_entry_rcu(t, &(signal)->thread_head, thread_node)
2638
2639 #define for_each_thread(p, t) \
2640 __for_each_thread((p)->signal, t)
2641
2642 /* Careful: this is a double loop, 'break' won't work as expected. */
2643 #define for_each_process_thread(p, t) \
2644 for_each_process(p) for_each_thread(p, t)
2645
2646 static inline int get_nr_threads(struct task_struct *tsk)
2647 {
2648 return tsk->signal->nr_threads;
2649 }
2650
2651 static inline bool thread_group_leader(struct task_struct *p)
2652 {
2653 return p->exit_signal >= 0;
2654 }
2655
2656 /* Do to the insanities of de_thread it is possible for a process
2657 * to have the pid of the thread group leader without actually being
2658 * the thread group leader. For iteration through the pids in proc
2659 * all we care about is that we have a task with the appropriate
2660 * pid, we don't actually care if we have the right task.
2661 */
2662 static inline bool has_group_leader_pid(struct task_struct *p)
2663 {
2664 return task_pid(p) == p->signal->leader_pid;
2665 }
2666
2667 static inline
2668 bool same_thread_group(struct task_struct *p1, struct task_struct *p2)
2669 {
2670 return p1->signal == p2->signal;
2671 }
2672
2673 static inline struct task_struct *next_thread(const struct task_struct *p)
2674 {
2675 return list_entry_rcu(p->thread_group.next,
2676 struct task_struct, thread_group);
2677 }
2678
2679 static inline int thread_group_empty(struct task_struct *p)
2680 {
2681 return list_empty(&p->thread_group);
2682 }
2683
2684 #define delay_group_leader(p) \
2685 (thread_group_leader(p) && !thread_group_empty(p))
2686
2687 /*
2688 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
2689 * subscriptions and synchronises with wait4(). Also used in procfs. Also
2690 * pins the final release of task.io_context. Also protects ->cpuset and
2691 * ->cgroup.subsys[]. And ->vfork_done.
2692 *
2693 * Nests both inside and outside of read_lock(&tasklist_lock).
2694 * It must not be nested with write_lock_irq(&tasklist_lock),
2695 * neither inside nor outside.
2696 */
2697 static inline void task_lock(struct task_struct *p)
2698 {
2699 spin_lock(&p->alloc_lock);
2700 }
2701
2702 static inline void task_unlock(struct task_struct *p)
2703 {
2704 spin_unlock(&p->alloc_lock);
2705 }
2706
2707 extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
2708 unsigned long *flags);
2709
2710 static inline struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
2711 unsigned long *flags)
2712 {
2713 struct sighand_struct *ret;
2714
2715 ret = __lock_task_sighand(tsk, flags);
2716 (void)__cond_lock(&tsk->sighand->siglock, ret);
2717 return ret;
2718 }
2719
2720 static inline void unlock_task_sighand(struct task_struct *tsk,
2721 unsigned long *flags)
2722 {
2723 spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
2724 }
2725
2726 /**
2727 * threadgroup_change_begin - mark the beginning of changes to a threadgroup
2728 * @tsk: task causing the changes
2729 *
2730 * All operations which modify a threadgroup - a new thread joining the
2731 * group, death of a member thread (the assertion of PF_EXITING) and
2732 * exec(2) dethreading the process and replacing the leader - are wrapped
2733 * by threadgroup_change_{begin|end}(). This is to provide a place which
2734 * subsystems needing threadgroup stability can hook into for
2735 * synchronization.
2736 */
2737 static inline void threadgroup_change_begin(struct task_struct *tsk)
2738 {
2739 might_sleep();
2740 cgroup_threadgroup_change_begin(tsk);
2741 }
2742
2743 /**
2744 * threadgroup_change_end - mark the end of changes to a threadgroup
2745 * @tsk: task causing the changes
2746 *
2747 * See threadgroup_change_begin().
2748 */
2749 static inline void threadgroup_change_end(struct task_struct *tsk)
2750 {
2751 cgroup_threadgroup_change_end(tsk);
2752 }
2753
2754 #ifndef __HAVE_THREAD_FUNCTIONS
2755
2756 #define task_thread_info(task) ((struct thread_info *)(task)->stack)
2757 #define task_stack_page(task) ((task)->stack)
2758
2759 static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
2760 {
2761 *task_thread_info(p) = *task_thread_info(org);
2762 task_thread_info(p)->task = p;
2763 }
2764
2765 /*
2766 * Return the address of the last usable long on the stack.
2767 *
2768 * When the stack grows down, this is just above the thread
2769 * info struct. Going any lower will corrupt the threadinfo.
2770 *
2771 * When the stack grows up, this is the highest address.
2772 * Beyond that position, we corrupt data on the next page.
2773 */
2774 static inline unsigned long *end_of_stack(struct task_struct *p)
2775 {
2776 #ifdef CONFIG_STACK_GROWSUP
2777 return (unsigned long *)((unsigned long)task_thread_info(p) + THREAD_SIZE) - 1;
2778 #else
2779 return (unsigned long *)(task_thread_info(p) + 1);
2780 #endif
2781 }
2782
2783 #endif
2784 #define task_stack_end_corrupted(task) \
2785 (*(end_of_stack(task)) != STACK_END_MAGIC)
2786
2787 static inline int object_is_on_stack(void *obj)
2788 {
2789 void *stack = task_stack_page(current);
2790
2791 return (obj >= stack) && (obj < (stack + THREAD_SIZE));
2792 }
2793
2794 extern void thread_info_cache_init(void);
2795
2796 #ifdef CONFIG_DEBUG_STACK_USAGE
2797 static inline unsigned long stack_not_used(struct task_struct *p)
2798 {
2799 unsigned long *n = end_of_stack(p);
2800
2801 do { /* Skip over canary */
2802 n++;
2803 } while (!*n);
2804
2805 return (unsigned long)n - (unsigned long)end_of_stack(p);
2806 }
2807 #endif
2808 extern void set_task_stack_end_magic(struct task_struct *tsk);
2809
2810 /* set thread flags in other task's structures
2811 * - see asm/thread_info.h for TIF_xxxx flags available
2812 */
2813 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2814 {
2815 set_ti_thread_flag(task_thread_info(tsk), flag);
2816 }
2817
2818 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2819 {
2820 clear_ti_thread_flag(task_thread_info(tsk), flag);
2821 }
2822
2823 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2824 {
2825 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2826 }
2827
2828 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2829 {
2830 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2831 }
2832
2833 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2834 {
2835 return test_ti_thread_flag(task_thread_info(tsk), flag);
2836 }
2837
2838 static inline void set_tsk_need_resched(struct task_struct *tsk)
2839 {
2840 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2841 }
2842
2843 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2844 {
2845 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2846 }
2847
2848 static inline int test_tsk_need_resched(struct task_struct *tsk)
2849 {
2850 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2851 }
2852
2853 static inline int restart_syscall(void)
2854 {
2855 set_tsk_thread_flag(current, TIF_SIGPENDING);
2856 return -ERESTARTNOINTR;
2857 }
2858
2859 static inline int signal_pending(struct task_struct *p)
2860 {
2861 return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
2862 }
2863
2864 static inline int __fatal_signal_pending(struct task_struct *p)
2865 {
2866 return unlikely(sigismember(&p->pending.signal, SIGKILL));
2867 }
2868
2869 static inline int fatal_signal_pending(struct task_struct *p)
2870 {
2871 return signal_pending(p) && __fatal_signal_pending(p);
2872 }
2873
2874 static inline int signal_pending_state(long state, struct task_struct *p)
2875 {
2876 if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
2877 return 0;
2878 if (!signal_pending(p))
2879 return 0;
2880
2881 return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
2882 }
2883
2884 /*
2885 * cond_resched() and cond_resched_lock(): latency reduction via
2886 * explicit rescheduling in places that are safe. The return
2887 * value indicates whether a reschedule was done in fact.
2888 * cond_resched_lock() will drop the spinlock before scheduling,
2889 * cond_resched_softirq() will enable bhs before scheduling.
2890 */
2891 extern int _cond_resched(void);
2892
2893 #define cond_resched() ({ \
2894 ___might_sleep(__FILE__, __LINE__, 0); \
2895 _cond_resched(); \
2896 })
2897
2898 extern int __cond_resched_lock(spinlock_t *lock);
2899
2900 #ifdef CONFIG_PREEMPT_COUNT
2901 #define PREEMPT_LOCK_OFFSET PREEMPT_OFFSET
2902 #else
2903 #define PREEMPT_LOCK_OFFSET 0
2904 #endif
2905
2906 #define cond_resched_lock(lock) ({ \
2907 ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
2908 __cond_resched_lock(lock); \
2909 })
2910
2911 extern int __cond_resched_softirq(void);
2912
2913 #define cond_resched_softirq() ({ \
2914 ___might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET); \
2915 __cond_resched_softirq(); \
2916 })
2917
2918 static inline void cond_resched_rcu(void)
2919 {
2920 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
2921 rcu_read_unlock();
2922 cond_resched();
2923 rcu_read_lock();
2924 #endif
2925 }
2926
2927 /*
2928 * Does a critical section need to be broken due to another
2929 * task waiting?: (technically does not depend on CONFIG_PREEMPT,
2930 * but a general need for low latency)
2931 */
2932 static inline int spin_needbreak(spinlock_t *lock)
2933 {
2934 #ifdef CONFIG_PREEMPT
2935 return spin_is_contended(lock);
2936 #else
2937 return 0;
2938 #endif
2939 }
2940
2941 /*
2942 * Idle thread specific functions to determine the need_resched
2943 * polling state.
2944 */
2945 #ifdef TIF_POLLING_NRFLAG
2946 static inline int tsk_is_polling(struct task_struct *p)
2947 {
2948 return test_tsk_thread_flag(p, TIF_POLLING_NRFLAG);
2949 }
2950
2951 static inline void __current_set_polling(void)
2952 {
2953 set_thread_flag(TIF_POLLING_NRFLAG);
2954 }
2955
2956 static inline bool __must_check current_set_polling_and_test(void)
2957 {
2958 __current_set_polling();
2959
2960 /*
2961 * Polling state must be visible before we test NEED_RESCHED,
2962 * paired by resched_curr()
2963 */
2964 smp_mb__after_atomic();
2965
2966 return unlikely(tif_need_resched());
2967 }
2968
2969 static inline void __current_clr_polling(void)
2970 {
2971 clear_thread_flag(TIF_POLLING_NRFLAG);
2972 }
2973
2974 static inline bool __must_check current_clr_polling_and_test(void)
2975 {
2976 __current_clr_polling();
2977
2978 /*
2979 * Polling state must be visible before we test NEED_RESCHED,
2980 * paired by resched_curr()
2981 */
2982 smp_mb__after_atomic();
2983
2984 return unlikely(tif_need_resched());
2985 }
2986
2987 #else
2988 static inline int tsk_is_polling(struct task_struct *p) { return 0; }
2989 static inline void __current_set_polling(void) { }
2990 static inline void __current_clr_polling(void) { }
2991
2992 static inline bool __must_check current_set_polling_and_test(void)
2993 {
2994 return unlikely(tif_need_resched());
2995 }
2996 static inline bool __must_check current_clr_polling_and_test(void)
2997 {
2998 return unlikely(tif_need_resched());
2999 }
3000 #endif
3001
3002 static inline void current_clr_polling(void)
3003 {
3004 __current_clr_polling();
3005
3006 /*
3007 * Ensure we check TIF_NEED_RESCHED after we clear the polling bit.
3008 * Once the bit is cleared, we'll get IPIs with every new
3009 * TIF_NEED_RESCHED and the IPI handler, scheduler_ipi(), will also
3010 * fold.
3011 */
3012 smp_mb(); /* paired with resched_curr() */
3013
3014 preempt_fold_need_resched();
3015 }
3016
3017 static __always_inline bool need_resched(void)
3018 {
3019 return unlikely(tif_need_resched());
3020 }
3021
3022 /*
3023 * Thread group CPU time accounting.
3024 */
3025 void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
3026 void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
3027
3028 /*
3029 * Reevaluate whether the task has signals pending delivery.
3030 * Wake the task if so.
3031 * This is required every time the blocked sigset_t changes.
3032 * callers must hold sighand->siglock.
3033 */
3034 extern void recalc_sigpending_and_wake(struct task_struct *t);
3035 extern void recalc_sigpending(void);
3036
3037 extern void signal_wake_up_state(struct task_struct *t, unsigned int state);
3038
3039 static inline void signal_wake_up(struct task_struct *t, bool resume)
3040 {
3041 signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0);
3042 }
3043 static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume)
3044 {
3045 signal_wake_up_state(t, resume ? __TASK_TRACED : 0);
3046 }
3047
3048 /*
3049 * Wrappers for p->thread_info->cpu access. No-op on UP.
3050 */
3051 #ifdef CONFIG_SMP
3052
3053 static inline unsigned int task_cpu(const struct task_struct *p)
3054 {
3055 return task_thread_info(p)->cpu;
3056 }
3057
3058 static inline int task_node(const struct task_struct *p)
3059 {
3060 return cpu_to_node(task_cpu(p));
3061 }
3062
3063 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
3064
3065 #else
3066
3067 static inline unsigned int task_cpu(const struct task_struct *p)
3068 {
3069 return 0;
3070 }
3071
3072 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
3073 {
3074 }
3075
3076 #endif /* CONFIG_SMP */
3077
3078 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
3079 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
3080
3081 #ifdef CONFIG_CGROUP_SCHED
3082 extern struct task_group root_task_group;
3083 #endif /* CONFIG_CGROUP_SCHED */
3084
3085 extern int task_can_switch_user(struct user_struct *up,
3086 struct task_struct *tsk);
3087
3088 #ifdef CONFIG_TASK_XACCT
3089 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
3090 {
3091 tsk->ioac.rchar += amt;
3092 }
3093
3094 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
3095 {
3096 tsk->ioac.wchar += amt;
3097 }
3098
3099 static inline void inc_syscr(struct task_struct *tsk)
3100 {
3101 tsk->ioac.syscr++;
3102 }
3103
3104 static inline void inc_syscw(struct task_struct *tsk)
3105 {
3106 tsk->ioac.syscw++;
3107 }
3108 #else
3109 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
3110 {
3111 }
3112
3113 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
3114 {
3115 }
3116
3117 static inline void inc_syscr(struct task_struct *tsk)
3118 {
3119 }
3120
3121 static inline void inc_syscw(struct task_struct *tsk)
3122 {
3123 }
3124 #endif
3125
3126 #ifndef TASK_SIZE_OF
3127 #define TASK_SIZE_OF(tsk) TASK_SIZE
3128 #endif
3129
3130 #ifdef CONFIG_MEMCG
3131 extern void mm_update_next_owner(struct mm_struct *mm);
3132 #else
3133 static inline void mm_update_next_owner(struct mm_struct *mm)
3134 {
3135 }
3136 #endif /* CONFIG_MEMCG */
3137
3138 static inline unsigned long task_rlimit(const struct task_struct *tsk,
3139 unsigned int limit)
3140 {
3141 return READ_ONCE(tsk->signal->rlim[limit].rlim_cur);
3142 }
3143
3144 static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
3145 unsigned int limit)
3146 {
3147 return READ_ONCE(tsk->signal->rlim[limit].rlim_max);
3148 }
3149
3150 static inline unsigned long rlimit(unsigned int limit)
3151 {
3152 return task_rlimit(current, limit);
3153 }
3154
3155 static inline unsigned long rlimit_max(unsigned int limit)
3156 {
3157 return task_rlimit_max(current, limit);
3158 }
3159
3160 #endif
This page took 0.131545 seconds and 6 git commands to generate.