Merge branch 'for-airlied' of git://people.freedesktop.org/~danvet/drm-intel into...
[deliverable/linux.git] / include / linux / sched.h
1 #ifndef _LINUX_SCHED_H
2 #define _LINUX_SCHED_H
3
4 /*
5 * cloning flags:
6 */
7 #define CSIGNAL 0x000000ff /* signal mask to be sent at exit */
8 #define CLONE_VM 0x00000100 /* set if VM shared between processes */
9 #define CLONE_FS 0x00000200 /* set if fs info shared between processes */
10 #define CLONE_FILES 0x00000400 /* set if open files shared between processes */
11 #define CLONE_SIGHAND 0x00000800 /* set if signal handlers and blocked signals shared */
12 #define CLONE_PTRACE 0x00002000 /* set if we want to let tracing continue on the child too */
13 #define CLONE_VFORK 0x00004000 /* set if the parent wants the child to wake it up on mm_release */
14 #define CLONE_PARENT 0x00008000 /* set if we want to have the same parent as the cloner */
15 #define CLONE_THREAD 0x00010000 /* Same thread group? */
16 #define CLONE_NEWNS 0x00020000 /* New namespace group? */
17 #define CLONE_SYSVSEM 0x00040000 /* share system V SEM_UNDO semantics */
18 #define CLONE_SETTLS 0x00080000 /* create a new TLS for the child */
19 #define CLONE_PARENT_SETTID 0x00100000 /* set the TID in the parent */
20 #define CLONE_CHILD_CLEARTID 0x00200000 /* clear the TID in the child */
21 #define CLONE_DETACHED 0x00400000 /* Unused, ignored */
22 #define CLONE_UNTRACED 0x00800000 /* set if the tracing process can't force CLONE_PTRACE on this clone */
23 #define CLONE_CHILD_SETTID 0x01000000 /* set the TID in the child */
24 /* 0x02000000 was previously the unused CLONE_STOPPED (Start in stopped state)
25 and is now available for re-use. */
26 #define CLONE_NEWUTS 0x04000000 /* New utsname group? */
27 #define CLONE_NEWIPC 0x08000000 /* New ipcs */
28 #define CLONE_NEWUSER 0x10000000 /* New user namespace */
29 #define CLONE_NEWPID 0x20000000 /* New pid namespace */
30 #define CLONE_NEWNET 0x40000000 /* New network namespace */
31 #define CLONE_IO 0x80000000 /* Clone io context */
32
33 /*
34 * Scheduling policies
35 */
36 #define SCHED_NORMAL 0
37 #define SCHED_FIFO 1
38 #define SCHED_RR 2
39 #define SCHED_BATCH 3
40 /* SCHED_ISO: reserved but not implemented yet */
41 #define SCHED_IDLE 5
42 /* Can be ORed in to make sure the process is reverted back to SCHED_NORMAL on fork */
43 #define SCHED_RESET_ON_FORK 0x40000000
44
45 #ifdef __KERNEL__
46
47 struct sched_param {
48 int sched_priority;
49 };
50
51 #include <asm/param.h> /* for HZ */
52
53 #include <linux/capability.h>
54 #include <linux/threads.h>
55 #include <linux/kernel.h>
56 #include <linux/types.h>
57 #include <linux/timex.h>
58 #include <linux/jiffies.h>
59 #include <linux/rbtree.h>
60 #include <linux/thread_info.h>
61 #include <linux/cpumask.h>
62 #include <linux/errno.h>
63 #include <linux/nodemask.h>
64 #include <linux/mm_types.h>
65
66 #include <asm/page.h>
67 #include <asm/ptrace.h>
68 #include <asm/cputime.h>
69
70 #include <linux/smp.h>
71 #include <linux/sem.h>
72 #include <linux/signal.h>
73 #include <linux/compiler.h>
74 #include <linux/completion.h>
75 #include <linux/pid.h>
76 #include <linux/percpu.h>
77 #include <linux/topology.h>
78 #include <linux/proportions.h>
79 #include <linux/seccomp.h>
80 #include <linux/rcupdate.h>
81 #include <linux/rculist.h>
82 #include <linux/rtmutex.h>
83
84 #include <linux/time.h>
85 #include <linux/param.h>
86 #include <linux/resource.h>
87 #include <linux/timer.h>
88 #include <linux/hrtimer.h>
89 #include <linux/task_io_accounting.h>
90 #include <linux/latencytop.h>
91 #include <linux/cred.h>
92 #include <linux/llist.h>
93 #include <linux/uidgid.h>
94
95 #include <asm/processor.h>
96
97 struct exec_domain;
98 struct futex_pi_state;
99 struct robust_list_head;
100 struct bio_list;
101 struct fs_struct;
102 struct perf_event_context;
103 struct blk_plug;
104
105 /*
106 * List of flags we want to share for kernel threads,
107 * if only because they are not used by them anyway.
108 */
109 #define CLONE_KERNEL (CLONE_FS | CLONE_FILES | CLONE_SIGHAND)
110
111 /*
112 * These are the constant used to fake the fixed-point load-average
113 * counting. Some notes:
114 * - 11 bit fractions expand to 22 bits by the multiplies: this gives
115 * a load-average precision of 10 bits integer + 11 bits fractional
116 * - if you want to count load-averages more often, you need more
117 * precision, or rounding will get you. With 2-second counting freq,
118 * the EXP_n values would be 1981, 2034 and 2043 if still using only
119 * 11 bit fractions.
120 */
121 extern unsigned long avenrun[]; /* Load averages */
122 extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
123
124 #define FSHIFT 11 /* nr of bits of precision */
125 #define FIXED_1 (1<<FSHIFT) /* 1.0 as fixed-point */
126 #define LOAD_FREQ (5*HZ+1) /* 5 sec intervals */
127 #define EXP_1 1884 /* 1/exp(5sec/1min) as fixed-point */
128 #define EXP_5 2014 /* 1/exp(5sec/5min) */
129 #define EXP_15 2037 /* 1/exp(5sec/15min) */
130
131 #define CALC_LOAD(load,exp,n) \
132 load *= exp; \
133 load += n*(FIXED_1-exp); \
134 load >>= FSHIFT;
135
136 extern unsigned long total_forks;
137 extern int nr_threads;
138 DECLARE_PER_CPU(unsigned long, process_counts);
139 extern int nr_processes(void);
140 extern unsigned long nr_running(void);
141 extern unsigned long nr_uninterruptible(void);
142 extern unsigned long nr_iowait(void);
143 extern unsigned long nr_iowait_cpu(int cpu);
144 extern unsigned long this_cpu_load(void);
145
146
147 extern void calc_global_load(unsigned long ticks);
148 extern void update_cpu_load_nohz(void);
149
150 extern unsigned long get_parent_ip(unsigned long addr);
151
152 struct seq_file;
153 struct cfs_rq;
154 struct task_group;
155 #ifdef CONFIG_SCHED_DEBUG
156 extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
157 extern void proc_sched_set_task(struct task_struct *p);
158 extern void
159 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
160 #else
161 static inline void
162 proc_sched_show_task(struct task_struct *p, struct seq_file *m)
163 {
164 }
165 static inline void proc_sched_set_task(struct task_struct *p)
166 {
167 }
168 static inline void
169 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
170 {
171 }
172 #endif
173
174 /*
175 * Task state bitmask. NOTE! These bits are also
176 * encoded in fs/proc/array.c: get_task_state().
177 *
178 * We have two separate sets of flags: task->state
179 * is about runnability, while task->exit_state are
180 * about the task exiting. Confusing, but this way
181 * modifying one set can't modify the other one by
182 * mistake.
183 */
184 #define TASK_RUNNING 0
185 #define TASK_INTERRUPTIBLE 1
186 #define TASK_UNINTERRUPTIBLE 2
187 #define __TASK_STOPPED 4
188 #define __TASK_TRACED 8
189 /* in tsk->exit_state */
190 #define EXIT_ZOMBIE 16
191 #define EXIT_DEAD 32
192 /* in tsk->state again */
193 #define TASK_DEAD 64
194 #define TASK_WAKEKILL 128
195 #define TASK_WAKING 256
196 #define TASK_STATE_MAX 512
197
198 #define TASK_STATE_TO_CHAR_STR "RSDTtZXxKW"
199
200 extern char ___assert_task_state[1 - 2*!!(
201 sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
202
203 /* Convenience macros for the sake of set_task_state */
204 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
205 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED)
206 #define TASK_TRACED (TASK_WAKEKILL | __TASK_TRACED)
207
208 /* Convenience macros for the sake of wake_up */
209 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
210 #define TASK_ALL (TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)
211
212 /* get_task_state() */
213 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \
214 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
215 __TASK_TRACED)
216
217 #define task_is_traced(task) ((task->state & __TASK_TRACED) != 0)
218 #define task_is_stopped(task) ((task->state & __TASK_STOPPED) != 0)
219 #define task_is_dead(task) ((task)->exit_state != 0)
220 #define task_is_stopped_or_traced(task) \
221 ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
222 #define task_contributes_to_load(task) \
223 ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
224 (task->flags & PF_FROZEN) == 0)
225
226 #define __set_task_state(tsk, state_value) \
227 do { (tsk)->state = (state_value); } while (0)
228 #define set_task_state(tsk, state_value) \
229 set_mb((tsk)->state, (state_value))
230
231 /*
232 * set_current_state() includes a barrier so that the write of current->state
233 * is correctly serialised wrt the caller's subsequent test of whether to
234 * actually sleep:
235 *
236 * set_current_state(TASK_UNINTERRUPTIBLE);
237 * if (do_i_need_to_sleep())
238 * schedule();
239 *
240 * If the caller does not need such serialisation then use __set_current_state()
241 */
242 #define __set_current_state(state_value) \
243 do { current->state = (state_value); } while (0)
244 #define set_current_state(state_value) \
245 set_mb(current->state, (state_value))
246
247 /* Task command name length */
248 #define TASK_COMM_LEN 16
249
250 #include <linux/spinlock.h>
251
252 /*
253 * This serializes "schedule()" and also protects
254 * the run-queue from deletions/modifications (but
255 * _adding_ to the beginning of the run-queue has
256 * a separate lock).
257 */
258 extern rwlock_t tasklist_lock;
259 extern spinlock_t mmlist_lock;
260
261 struct task_struct;
262
263 #ifdef CONFIG_PROVE_RCU
264 extern int lockdep_tasklist_lock_is_held(void);
265 #endif /* #ifdef CONFIG_PROVE_RCU */
266
267 extern void sched_init(void);
268 extern void sched_init_smp(void);
269 extern asmlinkage void schedule_tail(struct task_struct *prev);
270 extern void init_idle(struct task_struct *idle, int cpu);
271 extern void init_idle_bootup_task(struct task_struct *idle);
272
273 extern int runqueue_is_locked(int cpu);
274
275 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ)
276 extern void select_nohz_load_balancer(int stop_tick);
277 extern void set_cpu_sd_state_idle(void);
278 extern int get_nohz_timer_target(void);
279 #else
280 static inline void select_nohz_load_balancer(int stop_tick) { }
281 static inline void set_cpu_sd_state_idle(void) { }
282 #endif
283
284 /*
285 * Only dump TASK_* tasks. (0 for all tasks)
286 */
287 extern void show_state_filter(unsigned long state_filter);
288
289 static inline void show_state(void)
290 {
291 show_state_filter(0);
292 }
293
294 extern void show_regs(struct pt_regs *);
295
296 /*
297 * TASK is a pointer to the task whose backtrace we want to see (or NULL for current
298 * task), SP is the stack pointer of the first frame that should be shown in the back
299 * trace (or NULL if the entire call-chain of the task should be shown).
300 */
301 extern void show_stack(struct task_struct *task, unsigned long *sp);
302
303 void io_schedule(void);
304 long io_schedule_timeout(long timeout);
305
306 extern void cpu_init (void);
307 extern void trap_init(void);
308 extern void update_process_times(int user);
309 extern void scheduler_tick(void);
310
311 extern void sched_show_task(struct task_struct *p);
312
313 #ifdef CONFIG_LOCKUP_DETECTOR
314 extern void touch_softlockup_watchdog(void);
315 extern void touch_softlockup_watchdog_sync(void);
316 extern void touch_all_softlockup_watchdogs(void);
317 extern int proc_dowatchdog_thresh(struct ctl_table *table, int write,
318 void __user *buffer,
319 size_t *lenp, loff_t *ppos);
320 extern unsigned int softlockup_panic;
321 void lockup_detector_init(void);
322 #else
323 static inline void touch_softlockup_watchdog(void)
324 {
325 }
326 static inline void touch_softlockup_watchdog_sync(void)
327 {
328 }
329 static inline void touch_all_softlockup_watchdogs(void)
330 {
331 }
332 static inline void lockup_detector_init(void)
333 {
334 }
335 #endif
336
337 #ifdef CONFIG_DETECT_HUNG_TASK
338 extern unsigned int sysctl_hung_task_panic;
339 extern unsigned long sysctl_hung_task_check_count;
340 extern unsigned long sysctl_hung_task_timeout_secs;
341 extern unsigned long sysctl_hung_task_warnings;
342 extern int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
343 void __user *buffer,
344 size_t *lenp, loff_t *ppos);
345 #else
346 /* Avoid need for ifdefs elsewhere in the code */
347 enum { sysctl_hung_task_timeout_secs = 0 };
348 #endif
349
350 /* Attach to any functions which should be ignored in wchan output. */
351 #define __sched __attribute__((__section__(".sched.text")))
352
353 /* Linker adds these: start and end of __sched functions */
354 extern char __sched_text_start[], __sched_text_end[];
355
356 /* Is this address in the __sched functions? */
357 extern int in_sched_functions(unsigned long addr);
358
359 #define MAX_SCHEDULE_TIMEOUT LONG_MAX
360 extern signed long schedule_timeout(signed long timeout);
361 extern signed long schedule_timeout_interruptible(signed long timeout);
362 extern signed long schedule_timeout_killable(signed long timeout);
363 extern signed long schedule_timeout_uninterruptible(signed long timeout);
364 asmlinkage void schedule(void);
365 extern void schedule_preempt_disabled(void);
366 extern int mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner);
367
368 struct nsproxy;
369 struct user_namespace;
370
371 /*
372 * Default maximum number of active map areas, this limits the number of vmas
373 * per mm struct. Users can overwrite this number by sysctl but there is a
374 * problem.
375 *
376 * When a program's coredump is generated as ELF format, a section is created
377 * per a vma. In ELF, the number of sections is represented in unsigned short.
378 * This means the number of sections should be smaller than 65535 at coredump.
379 * Because the kernel adds some informative sections to a image of program at
380 * generating coredump, we need some margin. The number of extra sections is
381 * 1-3 now and depends on arch. We use "5" as safe margin, here.
382 */
383 #define MAPCOUNT_ELF_CORE_MARGIN (5)
384 #define DEFAULT_MAX_MAP_COUNT (USHRT_MAX - MAPCOUNT_ELF_CORE_MARGIN)
385
386 extern int sysctl_max_map_count;
387
388 #include <linux/aio.h>
389
390 #ifdef CONFIG_MMU
391 extern void arch_pick_mmap_layout(struct mm_struct *mm);
392 extern unsigned long
393 arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
394 unsigned long, unsigned long);
395 extern unsigned long
396 arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
397 unsigned long len, unsigned long pgoff,
398 unsigned long flags);
399 extern void arch_unmap_area(struct mm_struct *, unsigned long);
400 extern void arch_unmap_area_topdown(struct mm_struct *, unsigned long);
401 #else
402 static inline void arch_pick_mmap_layout(struct mm_struct *mm) {}
403 #endif
404
405
406 extern void set_dumpable(struct mm_struct *mm, int value);
407 extern int get_dumpable(struct mm_struct *mm);
408
409 /* get/set_dumpable() values */
410 #define SUID_DUMPABLE_DISABLED 0
411 #define SUID_DUMPABLE_ENABLED 1
412 #define SUID_DUMPABLE_SAFE 2
413
414 /* mm flags */
415 /* dumpable bits */
416 #define MMF_DUMPABLE 0 /* core dump is permitted */
417 #define MMF_DUMP_SECURELY 1 /* core file is readable only by root */
418
419 #define MMF_DUMPABLE_BITS 2
420 #define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
421
422 /* coredump filter bits */
423 #define MMF_DUMP_ANON_PRIVATE 2
424 #define MMF_DUMP_ANON_SHARED 3
425 #define MMF_DUMP_MAPPED_PRIVATE 4
426 #define MMF_DUMP_MAPPED_SHARED 5
427 #define MMF_DUMP_ELF_HEADERS 6
428 #define MMF_DUMP_HUGETLB_PRIVATE 7
429 #define MMF_DUMP_HUGETLB_SHARED 8
430
431 #define MMF_DUMP_FILTER_SHIFT MMF_DUMPABLE_BITS
432 #define MMF_DUMP_FILTER_BITS 7
433 #define MMF_DUMP_FILTER_MASK \
434 (((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT)
435 #define MMF_DUMP_FILTER_DEFAULT \
436 ((1 << MMF_DUMP_ANON_PRIVATE) | (1 << MMF_DUMP_ANON_SHARED) |\
437 (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF)
438
439 #ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
440 # define MMF_DUMP_MASK_DEFAULT_ELF (1 << MMF_DUMP_ELF_HEADERS)
441 #else
442 # define MMF_DUMP_MASK_DEFAULT_ELF 0
443 #endif
444 /* leave room for more dump flags */
445 #define MMF_VM_MERGEABLE 16 /* KSM may merge identical pages */
446 #define MMF_VM_HUGEPAGE 17 /* set when VM_HUGEPAGE is set on vma */
447 #define MMF_EXE_FILE_CHANGED 18 /* see prctl_set_mm_exe_file() */
448
449 #define MMF_INIT_MASK (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
450
451 struct sighand_struct {
452 atomic_t count;
453 struct k_sigaction action[_NSIG];
454 spinlock_t siglock;
455 wait_queue_head_t signalfd_wqh;
456 };
457
458 struct pacct_struct {
459 int ac_flag;
460 long ac_exitcode;
461 unsigned long ac_mem;
462 cputime_t ac_utime, ac_stime;
463 unsigned long ac_minflt, ac_majflt;
464 };
465
466 struct cpu_itimer {
467 cputime_t expires;
468 cputime_t incr;
469 u32 error;
470 u32 incr_error;
471 };
472
473 /**
474 * struct task_cputime - collected CPU time counts
475 * @utime: time spent in user mode, in &cputime_t units
476 * @stime: time spent in kernel mode, in &cputime_t units
477 * @sum_exec_runtime: total time spent on the CPU, in nanoseconds
478 *
479 * This structure groups together three kinds of CPU time that are
480 * tracked for threads and thread groups. Most things considering
481 * CPU time want to group these counts together and treat all three
482 * of them in parallel.
483 */
484 struct task_cputime {
485 cputime_t utime;
486 cputime_t stime;
487 unsigned long long sum_exec_runtime;
488 };
489 /* Alternate field names when used to cache expirations. */
490 #define prof_exp stime
491 #define virt_exp utime
492 #define sched_exp sum_exec_runtime
493
494 #define INIT_CPUTIME \
495 (struct task_cputime) { \
496 .utime = 0, \
497 .stime = 0, \
498 .sum_exec_runtime = 0, \
499 }
500
501 /*
502 * Disable preemption until the scheduler is running.
503 * Reset by start_kernel()->sched_init()->init_idle().
504 *
505 * We include PREEMPT_ACTIVE to avoid cond_resched() from working
506 * before the scheduler is active -- see should_resched().
507 */
508 #define INIT_PREEMPT_COUNT (1 + PREEMPT_ACTIVE)
509
510 /**
511 * struct thread_group_cputimer - thread group interval timer counts
512 * @cputime: thread group interval timers.
513 * @running: non-zero when there are timers running and
514 * @cputime receives updates.
515 * @lock: lock for fields in this struct.
516 *
517 * This structure contains the version of task_cputime, above, that is
518 * used for thread group CPU timer calculations.
519 */
520 struct thread_group_cputimer {
521 struct task_cputime cputime;
522 int running;
523 raw_spinlock_t lock;
524 };
525
526 #include <linux/rwsem.h>
527 struct autogroup;
528
529 /*
530 * NOTE! "signal_struct" does not have its own
531 * locking, because a shared signal_struct always
532 * implies a shared sighand_struct, so locking
533 * sighand_struct is always a proper superset of
534 * the locking of signal_struct.
535 */
536 struct signal_struct {
537 atomic_t sigcnt;
538 atomic_t live;
539 int nr_threads;
540
541 wait_queue_head_t wait_chldexit; /* for wait4() */
542
543 /* current thread group signal load-balancing target: */
544 struct task_struct *curr_target;
545
546 /* shared signal handling: */
547 struct sigpending shared_pending;
548
549 /* thread group exit support */
550 int group_exit_code;
551 /* overloaded:
552 * - notify group_exit_task when ->count is equal to notify_count
553 * - everyone except group_exit_task is stopped during signal delivery
554 * of fatal signals, group_exit_task processes the signal.
555 */
556 int notify_count;
557 struct task_struct *group_exit_task;
558
559 /* thread group stop support, overloads group_exit_code too */
560 int group_stop_count;
561 unsigned int flags; /* see SIGNAL_* flags below */
562
563 /*
564 * PR_SET_CHILD_SUBREAPER marks a process, like a service
565 * manager, to re-parent orphan (double-forking) child processes
566 * to this process instead of 'init'. The service manager is
567 * able to receive SIGCHLD signals and is able to investigate
568 * the process until it calls wait(). All children of this
569 * process will inherit a flag if they should look for a
570 * child_subreaper process at exit.
571 */
572 unsigned int is_child_subreaper:1;
573 unsigned int has_child_subreaper:1;
574
575 /* POSIX.1b Interval Timers */
576 struct list_head posix_timers;
577
578 /* ITIMER_REAL timer for the process */
579 struct hrtimer real_timer;
580 struct pid *leader_pid;
581 ktime_t it_real_incr;
582
583 /*
584 * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
585 * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
586 * values are defined to 0 and 1 respectively
587 */
588 struct cpu_itimer it[2];
589
590 /*
591 * Thread group totals for process CPU timers.
592 * See thread_group_cputimer(), et al, for details.
593 */
594 struct thread_group_cputimer cputimer;
595
596 /* Earliest-expiration cache. */
597 struct task_cputime cputime_expires;
598
599 struct list_head cpu_timers[3];
600
601 struct pid *tty_old_pgrp;
602
603 /* boolean value for session group leader */
604 int leader;
605
606 struct tty_struct *tty; /* NULL if no tty */
607
608 #ifdef CONFIG_SCHED_AUTOGROUP
609 struct autogroup *autogroup;
610 #endif
611 /*
612 * Cumulative resource counters for dead threads in the group,
613 * and for reaped dead child processes forked by this group.
614 * Live threads maintain their own counters and add to these
615 * in __exit_signal, except for the group leader.
616 */
617 cputime_t utime, stime, cutime, cstime;
618 cputime_t gtime;
619 cputime_t cgtime;
620 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
621 cputime_t prev_utime, prev_stime;
622 #endif
623 unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
624 unsigned long min_flt, maj_flt, cmin_flt, cmaj_flt;
625 unsigned long inblock, oublock, cinblock, coublock;
626 unsigned long maxrss, cmaxrss;
627 struct task_io_accounting ioac;
628
629 /*
630 * Cumulative ns of schedule CPU time fo dead threads in the
631 * group, not including a zombie group leader, (This only differs
632 * from jiffies_to_ns(utime + stime) if sched_clock uses something
633 * other than jiffies.)
634 */
635 unsigned long long sum_sched_runtime;
636
637 /*
638 * We don't bother to synchronize most readers of this at all,
639 * because there is no reader checking a limit that actually needs
640 * to get both rlim_cur and rlim_max atomically, and either one
641 * alone is a single word that can safely be read normally.
642 * getrlimit/setrlimit use task_lock(current->group_leader) to
643 * protect this instead of the siglock, because they really
644 * have no need to disable irqs.
645 */
646 struct rlimit rlim[RLIM_NLIMITS];
647
648 #ifdef CONFIG_BSD_PROCESS_ACCT
649 struct pacct_struct pacct; /* per-process accounting information */
650 #endif
651 #ifdef CONFIG_TASKSTATS
652 struct taskstats *stats;
653 #endif
654 #ifdef CONFIG_AUDIT
655 unsigned audit_tty;
656 struct tty_audit_buf *tty_audit_buf;
657 #endif
658 #ifdef CONFIG_CGROUPS
659 /*
660 * group_rwsem prevents new tasks from entering the threadgroup and
661 * member tasks from exiting,a more specifically, setting of
662 * PF_EXITING. fork and exit paths are protected with this rwsem
663 * using threadgroup_change_begin/end(). Users which require
664 * threadgroup to remain stable should use threadgroup_[un]lock()
665 * which also takes care of exec path. Currently, cgroup is the
666 * only user.
667 */
668 struct rw_semaphore group_rwsem;
669 #endif
670
671 int oom_adj; /* OOM kill score adjustment (bit shift) */
672 int oom_score_adj; /* OOM kill score adjustment */
673 int oom_score_adj_min; /* OOM kill score adjustment minimum value.
674 * Only settable by CAP_SYS_RESOURCE. */
675
676 struct mutex cred_guard_mutex; /* guard against foreign influences on
677 * credential calculations
678 * (notably. ptrace) */
679 };
680
681 /* Context switch must be unlocked if interrupts are to be enabled */
682 #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
683 # define __ARCH_WANT_UNLOCKED_CTXSW
684 #endif
685
686 /*
687 * Bits in flags field of signal_struct.
688 */
689 #define SIGNAL_STOP_STOPPED 0x00000001 /* job control stop in effect */
690 #define SIGNAL_STOP_CONTINUED 0x00000002 /* SIGCONT since WCONTINUED reap */
691 #define SIGNAL_GROUP_EXIT 0x00000004 /* group exit in progress */
692 /*
693 * Pending notifications to parent.
694 */
695 #define SIGNAL_CLD_STOPPED 0x00000010
696 #define SIGNAL_CLD_CONTINUED 0x00000020
697 #define SIGNAL_CLD_MASK (SIGNAL_CLD_STOPPED|SIGNAL_CLD_CONTINUED)
698
699 #define SIGNAL_UNKILLABLE 0x00000040 /* for init: ignore fatal signals */
700
701 /* If true, all threads except ->group_exit_task have pending SIGKILL */
702 static inline int signal_group_exit(const struct signal_struct *sig)
703 {
704 return (sig->flags & SIGNAL_GROUP_EXIT) ||
705 (sig->group_exit_task != NULL);
706 }
707
708 /*
709 * Some day this will be a full-fledged user tracking system..
710 */
711 struct user_struct {
712 atomic_t __count; /* reference count */
713 atomic_t processes; /* How many processes does this user have? */
714 atomic_t files; /* How many open files does this user have? */
715 atomic_t sigpending; /* How many pending signals does this user have? */
716 #ifdef CONFIG_INOTIFY_USER
717 atomic_t inotify_watches; /* How many inotify watches does this user have? */
718 atomic_t inotify_devs; /* How many inotify devs does this user have opened? */
719 #endif
720 #ifdef CONFIG_FANOTIFY
721 atomic_t fanotify_listeners;
722 #endif
723 #ifdef CONFIG_EPOLL
724 atomic_long_t epoll_watches; /* The number of file descriptors currently watched */
725 #endif
726 #ifdef CONFIG_POSIX_MQUEUE
727 /* protected by mq_lock */
728 unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */
729 #endif
730 unsigned long locked_shm; /* How many pages of mlocked shm ? */
731
732 #ifdef CONFIG_KEYS
733 struct key *uid_keyring; /* UID specific keyring */
734 struct key *session_keyring; /* UID's default session keyring */
735 #endif
736
737 /* Hash table maintenance information */
738 struct hlist_node uidhash_node;
739 kuid_t uid;
740
741 #ifdef CONFIG_PERF_EVENTS
742 atomic_long_t locked_vm;
743 #endif
744 };
745
746 extern int uids_sysfs_init(void);
747
748 extern struct user_struct *find_user(kuid_t);
749
750 extern struct user_struct root_user;
751 #define INIT_USER (&root_user)
752
753
754 struct backing_dev_info;
755 struct reclaim_state;
756
757 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
758 struct sched_info {
759 /* cumulative counters */
760 unsigned long pcount; /* # of times run on this cpu */
761 unsigned long long run_delay; /* time spent waiting on a runqueue */
762
763 /* timestamps */
764 unsigned long long last_arrival,/* when we last ran on a cpu */
765 last_queued; /* when we were last queued to run */
766 };
767 #endif /* defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) */
768
769 #ifdef CONFIG_TASK_DELAY_ACCT
770 struct task_delay_info {
771 spinlock_t lock;
772 unsigned int flags; /* Private per-task flags */
773
774 /* For each stat XXX, add following, aligned appropriately
775 *
776 * struct timespec XXX_start, XXX_end;
777 * u64 XXX_delay;
778 * u32 XXX_count;
779 *
780 * Atomicity of updates to XXX_delay, XXX_count protected by
781 * single lock above (split into XXX_lock if contention is an issue).
782 */
783
784 /*
785 * XXX_count is incremented on every XXX operation, the delay
786 * associated with the operation is added to XXX_delay.
787 * XXX_delay contains the accumulated delay time in nanoseconds.
788 */
789 struct timespec blkio_start, blkio_end; /* Shared by blkio, swapin */
790 u64 blkio_delay; /* wait for sync block io completion */
791 u64 swapin_delay; /* wait for swapin block io completion */
792 u32 blkio_count; /* total count of the number of sync block */
793 /* io operations performed */
794 u32 swapin_count; /* total count of the number of swapin block */
795 /* io operations performed */
796
797 struct timespec freepages_start, freepages_end;
798 u64 freepages_delay; /* wait for memory reclaim */
799 u32 freepages_count; /* total count of memory reclaim */
800 };
801 #endif /* CONFIG_TASK_DELAY_ACCT */
802
803 static inline int sched_info_on(void)
804 {
805 #ifdef CONFIG_SCHEDSTATS
806 return 1;
807 #elif defined(CONFIG_TASK_DELAY_ACCT)
808 extern int delayacct_on;
809 return delayacct_on;
810 #else
811 return 0;
812 #endif
813 }
814
815 enum cpu_idle_type {
816 CPU_IDLE,
817 CPU_NOT_IDLE,
818 CPU_NEWLY_IDLE,
819 CPU_MAX_IDLE_TYPES
820 };
821
822 /*
823 * Increase resolution of nice-level calculations for 64-bit architectures.
824 * The extra resolution improves shares distribution and load balancing of
825 * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup
826 * hierarchies, especially on larger systems. This is not a user-visible change
827 * and does not change the user-interface for setting shares/weights.
828 *
829 * We increase resolution only if we have enough bits to allow this increased
830 * resolution (i.e. BITS_PER_LONG > 32). The costs for increasing resolution
831 * when BITS_PER_LONG <= 32 are pretty high and the returns do not justify the
832 * increased costs.
833 */
834 #if 0 /* BITS_PER_LONG > 32 -- currently broken: it increases power usage under light load */
835 # define SCHED_LOAD_RESOLUTION 10
836 # define scale_load(w) ((w) << SCHED_LOAD_RESOLUTION)
837 # define scale_load_down(w) ((w) >> SCHED_LOAD_RESOLUTION)
838 #else
839 # define SCHED_LOAD_RESOLUTION 0
840 # define scale_load(w) (w)
841 # define scale_load_down(w) (w)
842 #endif
843
844 #define SCHED_LOAD_SHIFT (10 + SCHED_LOAD_RESOLUTION)
845 #define SCHED_LOAD_SCALE (1L << SCHED_LOAD_SHIFT)
846
847 /*
848 * Increase resolution of cpu_power calculations
849 */
850 #define SCHED_POWER_SHIFT 10
851 #define SCHED_POWER_SCALE (1L << SCHED_POWER_SHIFT)
852
853 /*
854 * sched-domains (multiprocessor balancing) declarations:
855 */
856 #ifdef CONFIG_SMP
857 #define SD_LOAD_BALANCE 0x0001 /* Do load balancing on this domain. */
858 #define SD_BALANCE_NEWIDLE 0x0002 /* Balance when about to become idle */
859 #define SD_BALANCE_EXEC 0x0004 /* Balance on exec */
860 #define SD_BALANCE_FORK 0x0008 /* Balance on fork, clone */
861 #define SD_BALANCE_WAKE 0x0010 /* Balance on wakeup */
862 #define SD_WAKE_AFFINE 0x0020 /* Wake task to waking CPU */
863 #define SD_PREFER_LOCAL 0x0040 /* Prefer to keep tasks local to this domain */
864 #define SD_SHARE_CPUPOWER 0x0080 /* Domain members share cpu power */
865 #define SD_SHARE_PKG_RESOURCES 0x0200 /* Domain members share cpu pkg resources */
866 #define SD_SERIALIZE 0x0400 /* Only a single load balancing instance */
867 #define SD_ASYM_PACKING 0x0800 /* Place busy groups earlier in the domain */
868 #define SD_PREFER_SIBLING 0x1000 /* Prefer to place tasks in a sibling domain */
869 #define SD_OVERLAP 0x2000 /* sched_domains of this level overlap */
870
871 extern int __weak arch_sd_sibiling_asym_packing(void);
872
873 struct sched_group_power {
874 atomic_t ref;
875 /*
876 * CPU power of this group, SCHED_LOAD_SCALE being max power for a
877 * single CPU.
878 */
879 unsigned int power, power_orig;
880 unsigned long next_update;
881 /*
882 * Number of busy cpus in this group.
883 */
884 atomic_t nr_busy_cpus;
885
886 unsigned long cpumask[0]; /* iteration mask */
887 };
888
889 struct sched_group {
890 struct sched_group *next; /* Must be a circular list */
891 atomic_t ref;
892
893 unsigned int group_weight;
894 struct sched_group_power *sgp;
895
896 /*
897 * The CPUs this group covers.
898 *
899 * NOTE: this field is variable length. (Allocated dynamically
900 * by attaching extra space to the end of the structure,
901 * depending on how many CPUs the kernel has booted up with)
902 */
903 unsigned long cpumask[0];
904 };
905
906 static inline struct cpumask *sched_group_cpus(struct sched_group *sg)
907 {
908 return to_cpumask(sg->cpumask);
909 }
910
911 /*
912 * cpumask masking which cpus in the group are allowed to iterate up the domain
913 * tree.
914 */
915 static inline struct cpumask *sched_group_mask(struct sched_group *sg)
916 {
917 return to_cpumask(sg->sgp->cpumask);
918 }
919
920 /**
921 * group_first_cpu - Returns the first cpu in the cpumask of a sched_group.
922 * @group: The group whose first cpu is to be returned.
923 */
924 static inline unsigned int group_first_cpu(struct sched_group *group)
925 {
926 return cpumask_first(sched_group_cpus(group));
927 }
928
929 struct sched_domain_attr {
930 int relax_domain_level;
931 };
932
933 #define SD_ATTR_INIT (struct sched_domain_attr) { \
934 .relax_domain_level = -1, \
935 }
936
937 extern int sched_domain_level_max;
938
939 struct sched_domain {
940 /* These fields must be setup */
941 struct sched_domain *parent; /* top domain must be null terminated */
942 struct sched_domain *child; /* bottom domain must be null terminated */
943 struct sched_group *groups; /* the balancing groups of the domain */
944 unsigned long min_interval; /* Minimum balance interval ms */
945 unsigned long max_interval; /* Maximum balance interval ms */
946 unsigned int busy_factor; /* less balancing by factor if busy */
947 unsigned int imbalance_pct; /* No balance until over watermark */
948 unsigned int cache_nice_tries; /* Leave cache hot tasks for # tries */
949 unsigned int busy_idx;
950 unsigned int idle_idx;
951 unsigned int newidle_idx;
952 unsigned int wake_idx;
953 unsigned int forkexec_idx;
954 unsigned int smt_gain;
955 int flags; /* See SD_* */
956 int level;
957
958 /* Runtime fields. */
959 unsigned long last_balance; /* init to jiffies. units in jiffies */
960 unsigned int balance_interval; /* initialise to 1. units in ms. */
961 unsigned int nr_balance_failed; /* initialise to 0 */
962
963 u64 last_update;
964
965 #ifdef CONFIG_SCHEDSTATS
966 /* load_balance() stats */
967 unsigned int lb_count[CPU_MAX_IDLE_TYPES];
968 unsigned int lb_failed[CPU_MAX_IDLE_TYPES];
969 unsigned int lb_balanced[CPU_MAX_IDLE_TYPES];
970 unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES];
971 unsigned int lb_gained[CPU_MAX_IDLE_TYPES];
972 unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES];
973 unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES];
974 unsigned int lb_nobusyq[CPU_MAX_IDLE_TYPES];
975
976 /* Active load balancing */
977 unsigned int alb_count;
978 unsigned int alb_failed;
979 unsigned int alb_pushed;
980
981 /* SD_BALANCE_EXEC stats */
982 unsigned int sbe_count;
983 unsigned int sbe_balanced;
984 unsigned int sbe_pushed;
985
986 /* SD_BALANCE_FORK stats */
987 unsigned int sbf_count;
988 unsigned int sbf_balanced;
989 unsigned int sbf_pushed;
990
991 /* try_to_wake_up() stats */
992 unsigned int ttwu_wake_remote;
993 unsigned int ttwu_move_affine;
994 unsigned int ttwu_move_balance;
995 #endif
996 #ifdef CONFIG_SCHED_DEBUG
997 char *name;
998 #endif
999 union {
1000 void *private; /* used during construction */
1001 struct rcu_head rcu; /* used during destruction */
1002 };
1003
1004 unsigned int span_weight;
1005 /*
1006 * Span of all CPUs in this domain.
1007 *
1008 * NOTE: this field is variable length. (Allocated dynamically
1009 * by attaching extra space to the end of the structure,
1010 * depending on how many CPUs the kernel has booted up with)
1011 */
1012 unsigned long span[0];
1013 };
1014
1015 static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
1016 {
1017 return to_cpumask(sd->span);
1018 }
1019
1020 extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1021 struct sched_domain_attr *dattr_new);
1022
1023 /* Allocate an array of sched domains, for partition_sched_domains(). */
1024 cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
1025 void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
1026
1027 /* Test a flag in parent sched domain */
1028 static inline int test_sd_parent(struct sched_domain *sd, int flag)
1029 {
1030 if (sd->parent && (sd->parent->flags & flag))
1031 return 1;
1032
1033 return 0;
1034 }
1035
1036 unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu);
1037 unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu);
1038
1039 bool cpus_share_cache(int this_cpu, int that_cpu);
1040
1041 #else /* CONFIG_SMP */
1042
1043 struct sched_domain_attr;
1044
1045 static inline void
1046 partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
1047 struct sched_domain_attr *dattr_new)
1048 {
1049 }
1050
1051 static inline bool cpus_share_cache(int this_cpu, int that_cpu)
1052 {
1053 return true;
1054 }
1055
1056 #endif /* !CONFIG_SMP */
1057
1058
1059 struct io_context; /* See blkdev.h */
1060
1061
1062 #ifdef ARCH_HAS_PREFETCH_SWITCH_STACK
1063 extern void prefetch_stack(struct task_struct *t);
1064 #else
1065 static inline void prefetch_stack(struct task_struct *t) { }
1066 #endif
1067
1068 struct audit_context; /* See audit.c */
1069 struct mempolicy;
1070 struct pipe_inode_info;
1071 struct uts_namespace;
1072
1073 struct rq;
1074 struct sched_domain;
1075
1076 /*
1077 * wake flags
1078 */
1079 #define WF_SYNC 0x01 /* waker goes to sleep after wakup */
1080 #define WF_FORK 0x02 /* child wakeup after fork */
1081 #define WF_MIGRATED 0x04 /* internal use, task got migrated */
1082
1083 #define ENQUEUE_WAKEUP 1
1084 #define ENQUEUE_HEAD 2
1085 #ifdef CONFIG_SMP
1086 #define ENQUEUE_WAKING 4 /* sched_class::task_waking was called */
1087 #else
1088 #define ENQUEUE_WAKING 0
1089 #endif
1090
1091 #define DEQUEUE_SLEEP 1
1092
1093 struct sched_class {
1094 const struct sched_class *next;
1095
1096 void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags);
1097 void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags);
1098 void (*yield_task) (struct rq *rq);
1099 bool (*yield_to_task) (struct rq *rq, struct task_struct *p, bool preempt);
1100
1101 void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags);
1102
1103 struct task_struct * (*pick_next_task) (struct rq *rq);
1104 void (*put_prev_task) (struct rq *rq, struct task_struct *p);
1105
1106 #ifdef CONFIG_SMP
1107 int (*select_task_rq)(struct task_struct *p, int sd_flag, int flags);
1108
1109 void (*pre_schedule) (struct rq *this_rq, struct task_struct *task);
1110 void (*post_schedule) (struct rq *this_rq);
1111 void (*task_waking) (struct task_struct *task);
1112 void (*task_woken) (struct rq *this_rq, struct task_struct *task);
1113
1114 void (*set_cpus_allowed)(struct task_struct *p,
1115 const struct cpumask *newmask);
1116
1117 void (*rq_online)(struct rq *rq);
1118 void (*rq_offline)(struct rq *rq);
1119 #endif
1120
1121 void (*set_curr_task) (struct rq *rq);
1122 void (*task_tick) (struct rq *rq, struct task_struct *p, int queued);
1123 void (*task_fork) (struct task_struct *p);
1124
1125 void (*switched_from) (struct rq *this_rq, struct task_struct *task);
1126 void (*switched_to) (struct rq *this_rq, struct task_struct *task);
1127 void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
1128 int oldprio);
1129
1130 unsigned int (*get_rr_interval) (struct rq *rq,
1131 struct task_struct *task);
1132
1133 #ifdef CONFIG_FAIR_GROUP_SCHED
1134 void (*task_move_group) (struct task_struct *p, int on_rq);
1135 #endif
1136 };
1137
1138 struct load_weight {
1139 unsigned long weight, inv_weight;
1140 };
1141
1142 #ifdef CONFIG_SCHEDSTATS
1143 struct sched_statistics {
1144 u64 wait_start;
1145 u64 wait_max;
1146 u64 wait_count;
1147 u64 wait_sum;
1148 u64 iowait_count;
1149 u64 iowait_sum;
1150
1151 u64 sleep_start;
1152 u64 sleep_max;
1153 s64 sum_sleep_runtime;
1154
1155 u64 block_start;
1156 u64 block_max;
1157 u64 exec_max;
1158 u64 slice_max;
1159
1160 u64 nr_migrations_cold;
1161 u64 nr_failed_migrations_affine;
1162 u64 nr_failed_migrations_running;
1163 u64 nr_failed_migrations_hot;
1164 u64 nr_forced_migrations;
1165
1166 u64 nr_wakeups;
1167 u64 nr_wakeups_sync;
1168 u64 nr_wakeups_migrate;
1169 u64 nr_wakeups_local;
1170 u64 nr_wakeups_remote;
1171 u64 nr_wakeups_affine;
1172 u64 nr_wakeups_affine_attempts;
1173 u64 nr_wakeups_passive;
1174 u64 nr_wakeups_idle;
1175 };
1176 #endif
1177
1178 struct sched_entity {
1179 struct load_weight load; /* for load-balancing */
1180 struct rb_node run_node;
1181 struct list_head group_node;
1182 unsigned int on_rq;
1183
1184 u64 exec_start;
1185 u64 sum_exec_runtime;
1186 u64 vruntime;
1187 u64 prev_sum_exec_runtime;
1188
1189 u64 nr_migrations;
1190
1191 #ifdef CONFIG_SCHEDSTATS
1192 struct sched_statistics statistics;
1193 #endif
1194
1195 #ifdef CONFIG_FAIR_GROUP_SCHED
1196 struct sched_entity *parent;
1197 /* rq on which this entity is (to be) queued: */
1198 struct cfs_rq *cfs_rq;
1199 /* rq "owned" by this entity/group: */
1200 struct cfs_rq *my_q;
1201 #endif
1202 };
1203
1204 struct sched_rt_entity {
1205 struct list_head run_list;
1206 unsigned long timeout;
1207 unsigned int time_slice;
1208
1209 struct sched_rt_entity *back;
1210 #ifdef CONFIG_RT_GROUP_SCHED
1211 struct sched_rt_entity *parent;
1212 /* rq on which this entity is (to be) queued: */
1213 struct rt_rq *rt_rq;
1214 /* rq "owned" by this entity/group: */
1215 struct rt_rq *my_q;
1216 #endif
1217 };
1218
1219 /*
1220 * default timeslice is 100 msecs (used only for SCHED_RR tasks).
1221 * Timeslices get refilled after they expire.
1222 */
1223 #define RR_TIMESLICE (100 * HZ / 1000)
1224
1225 struct rcu_node;
1226
1227 enum perf_event_task_context {
1228 perf_invalid_context = -1,
1229 perf_hw_context = 0,
1230 perf_sw_context,
1231 perf_nr_task_contexts,
1232 };
1233
1234 struct task_struct {
1235 volatile long state; /* -1 unrunnable, 0 runnable, >0 stopped */
1236 void *stack;
1237 atomic_t usage;
1238 unsigned int flags; /* per process flags, defined below */
1239 unsigned int ptrace;
1240
1241 #ifdef CONFIG_SMP
1242 struct llist_node wake_entry;
1243 int on_cpu;
1244 #endif
1245 int on_rq;
1246
1247 int prio, static_prio, normal_prio;
1248 unsigned int rt_priority;
1249 const struct sched_class *sched_class;
1250 struct sched_entity se;
1251 struct sched_rt_entity rt;
1252 #ifdef CONFIG_CGROUP_SCHED
1253 struct task_group *sched_task_group;
1254 #endif
1255
1256 #ifdef CONFIG_PREEMPT_NOTIFIERS
1257 /* list of struct preempt_notifier: */
1258 struct hlist_head preempt_notifiers;
1259 #endif
1260
1261 /*
1262 * fpu_counter contains the number of consecutive context switches
1263 * that the FPU is used. If this is over a threshold, the lazy fpu
1264 * saving becomes unlazy to save the trap. This is an unsigned char
1265 * so that after 256 times the counter wraps and the behavior turns
1266 * lazy again; this to deal with bursty apps that only use FPU for
1267 * a short time
1268 */
1269 unsigned char fpu_counter;
1270 #ifdef CONFIG_BLK_DEV_IO_TRACE
1271 unsigned int btrace_seq;
1272 #endif
1273
1274 unsigned int policy;
1275 int nr_cpus_allowed;
1276 cpumask_t cpus_allowed;
1277
1278 #ifdef CONFIG_PREEMPT_RCU
1279 int rcu_read_lock_nesting;
1280 char rcu_read_unlock_special;
1281 struct list_head rcu_node_entry;
1282 #endif /* #ifdef CONFIG_PREEMPT_RCU */
1283 #ifdef CONFIG_TREE_PREEMPT_RCU
1284 struct rcu_node *rcu_blocked_node;
1285 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
1286 #ifdef CONFIG_RCU_BOOST
1287 struct rt_mutex *rcu_boost_mutex;
1288 #endif /* #ifdef CONFIG_RCU_BOOST */
1289
1290 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
1291 struct sched_info sched_info;
1292 #endif
1293
1294 struct list_head tasks;
1295 #ifdef CONFIG_SMP
1296 struct plist_node pushable_tasks;
1297 #endif
1298
1299 struct mm_struct *mm, *active_mm;
1300 #ifdef CONFIG_COMPAT_BRK
1301 unsigned brk_randomized:1;
1302 #endif
1303 #if defined(SPLIT_RSS_COUNTING)
1304 struct task_rss_stat rss_stat;
1305 #endif
1306 /* task state */
1307 int exit_state;
1308 int exit_code, exit_signal;
1309 int pdeath_signal; /* The signal sent when the parent dies */
1310 unsigned int jobctl; /* JOBCTL_*, siglock protected */
1311 /* ??? */
1312 unsigned int personality;
1313 unsigned did_exec:1;
1314 unsigned in_execve:1; /* Tell the LSMs that the process is doing an
1315 * execve */
1316 unsigned in_iowait:1;
1317
1318 /* task may not gain privileges */
1319 unsigned no_new_privs:1;
1320
1321 /* Revert to default priority/policy when forking */
1322 unsigned sched_reset_on_fork:1;
1323 unsigned sched_contributes_to_load:1;
1324
1325 pid_t pid;
1326 pid_t tgid;
1327
1328 #ifdef CONFIG_CC_STACKPROTECTOR
1329 /* Canary value for the -fstack-protector gcc feature */
1330 unsigned long stack_canary;
1331 #endif
1332 /*
1333 * pointers to (original) parent process, youngest child, younger sibling,
1334 * older sibling, respectively. (p->father can be replaced with
1335 * p->real_parent->pid)
1336 */
1337 struct task_struct __rcu *real_parent; /* real parent process */
1338 struct task_struct __rcu *parent; /* recipient of SIGCHLD, wait4() reports */
1339 /*
1340 * children/sibling forms the list of my natural children
1341 */
1342 struct list_head children; /* list of my children */
1343 struct list_head sibling; /* linkage in my parent's children list */
1344 struct task_struct *group_leader; /* threadgroup leader */
1345
1346 /*
1347 * ptraced is the list of tasks this task is using ptrace on.
1348 * This includes both natural children and PTRACE_ATTACH targets.
1349 * p->ptrace_entry is p's link on the p->parent->ptraced list.
1350 */
1351 struct list_head ptraced;
1352 struct list_head ptrace_entry;
1353
1354 /* PID/PID hash table linkage. */
1355 struct pid_link pids[PIDTYPE_MAX];
1356 struct list_head thread_group;
1357
1358 struct completion *vfork_done; /* for vfork() */
1359 int __user *set_child_tid; /* CLONE_CHILD_SETTID */
1360 int __user *clear_child_tid; /* CLONE_CHILD_CLEARTID */
1361
1362 cputime_t utime, stime, utimescaled, stimescaled;
1363 cputime_t gtime;
1364 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
1365 cputime_t prev_utime, prev_stime;
1366 #endif
1367 unsigned long nvcsw, nivcsw; /* context switch counts */
1368 struct timespec start_time; /* monotonic time */
1369 struct timespec real_start_time; /* boot based time */
1370 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
1371 unsigned long min_flt, maj_flt;
1372
1373 struct task_cputime cputime_expires;
1374 struct list_head cpu_timers[3];
1375
1376 /* process credentials */
1377 const struct cred __rcu *real_cred; /* objective and real subjective task
1378 * credentials (COW) */
1379 const struct cred __rcu *cred; /* effective (overridable) subjective task
1380 * credentials (COW) */
1381 char comm[TASK_COMM_LEN]; /* executable name excluding path
1382 - access with [gs]et_task_comm (which lock
1383 it with task_lock())
1384 - initialized normally by setup_new_exec */
1385 /* file system info */
1386 int link_count, total_link_count;
1387 #ifdef CONFIG_SYSVIPC
1388 /* ipc stuff */
1389 struct sysv_sem sysvsem;
1390 #endif
1391 #ifdef CONFIG_DETECT_HUNG_TASK
1392 /* hung task detection */
1393 unsigned long last_switch_count;
1394 #endif
1395 /* CPU-specific state of this task */
1396 struct thread_struct thread;
1397 /* filesystem information */
1398 struct fs_struct *fs;
1399 /* open file information */
1400 struct files_struct *files;
1401 /* namespaces */
1402 struct nsproxy *nsproxy;
1403 /* signal handlers */
1404 struct signal_struct *signal;
1405 struct sighand_struct *sighand;
1406
1407 sigset_t blocked, real_blocked;
1408 sigset_t saved_sigmask; /* restored if set_restore_sigmask() was used */
1409 struct sigpending pending;
1410
1411 unsigned long sas_ss_sp;
1412 size_t sas_ss_size;
1413 int (*notifier)(void *priv);
1414 void *notifier_data;
1415 sigset_t *notifier_mask;
1416 struct callback_head *task_works;
1417
1418 struct audit_context *audit_context;
1419 #ifdef CONFIG_AUDITSYSCALL
1420 uid_t loginuid;
1421 unsigned int sessionid;
1422 #endif
1423 struct seccomp seccomp;
1424
1425 /* Thread group tracking */
1426 u32 parent_exec_id;
1427 u32 self_exec_id;
1428 /* Protection of (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed,
1429 * mempolicy */
1430 spinlock_t alloc_lock;
1431
1432 /* Protection of the PI data structures: */
1433 raw_spinlock_t pi_lock;
1434
1435 #ifdef CONFIG_RT_MUTEXES
1436 /* PI waiters blocked on a rt_mutex held by this task */
1437 struct plist_head pi_waiters;
1438 /* Deadlock detection and priority inheritance handling */
1439 struct rt_mutex_waiter *pi_blocked_on;
1440 #endif
1441
1442 #ifdef CONFIG_DEBUG_MUTEXES
1443 /* mutex deadlock detection */
1444 struct mutex_waiter *blocked_on;
1445 #endif
1446 #ifdef CONFIG_TRACE_IRQFLAGS
1447 unsigned int irq_events;
1448 unsigned long hardirq_enable_ip;
1449 unsigned long hardirq_disable_ip;
1450 unsigned int hardirq_enable_event;
1451 unsigned int hardirq_disable_event;
1452 int hardirqs_enabled;
1453 int hardirq_context;
1454 unsigned long softirq_disable_ip;
1455 unsigned long softirq_enable_ip;
1456 unsigned int softirq_disable_event;
1457 unsigned int softirq_enable_event;
1458 int softirqs_enabled;
1459 int softirq_context;
1460 #endif
1461 #ifdef CONFIG_LOCKDEP
1462 # define MAX_LOCK_DEPTH 48UL
1463 u64 curr_chain_key;
1464 int lockdep_depth;
1465 unsigned int lockdep_recursion;
1466 struct held_lock held_locks[MAX_LOCK_DEPTH];
1467 gfp_t lockdep_reclaim_gfp;
1468 #endif
1469
1470 /* journalling filesystem info */
1471 void *journal_info;
1472
1473 /* stacked block device info */
1474 struct bio_list *bio_list;
1475
1476 #ifdef CONFIG_BLOCK
1477 /* stack plugging */
1478 struct blk_plug *plug;
1479 #endif
1480
1481 /* VM state */
1482 struct reclaim_state *reclaim_state;
1483
1484 struct backing_dev_info *backing_dev_info;
1485
1486 struct io_context *io_context;
1487
1488 unsigned long ptrace_message;
1489 siginfo_t *last_siginfo; /* For ptrace use. */
1490 struct task_io_accounting ioac;
1491 #if defined(CONFIG_TASK_XACCT)
1492 u64 acct_rss_mem1; /* accumulated rss usage */
1493 u64 acct_vm_mem1; /* accumulated virtual memory usage */
1494 cputime_t acct_timexpd; /* stime + utime since last update */
1495 #endif
1496 #ifdef CONFIG_CPUSETS
1497 nodemask_t mems_allowed; /* Protected by alloc_lock */
1498 seqcount_t mems_allowed_seq; /* Seqence no to catch updates */
1499 int cpuset_mem_spread_rotor;
1500 int cpuset_slab_spread_rotor;
1501 #endif
1502 #ifdef CONFIG_CGROUPS
1503 /* Control Group info protected by css_set_lock */
1504 struct css_set __rcu *cgroups;
1505 /* cg_list protected by css_set_lock and tsk->alloc_lock */
1506 struct list_head cg_list;
1507 #endif
1508 #ifdef CONFIG_FUTEX
1509 struct robust_list_head __user *robust_list;
1510 #ifdef CONFIG_COMPAT
1511 struct compat_robust_list_head __user *compat_robust_list;
1512 #endif
1513 struct list_head pi_state_list;
1514 struct futex_pi_state *pi_state_cache;
1515 #endif
1516 #ifdef CONFIG_PERF_EVENTS
1517 struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1518 struct mutex perf_event_mutex;
1519 struct list_head perf_event_list;
1520 #endif
1521 #ifdef CONFIG_NUMA
1522 struct mempolicy *mempolicy; /* Protected by alloc_lock */
1523 short il_next;
1524 short pref_node_fork;
1525 #endif
1526 struct rcu_head rcu;
1527
1528 /*
1529 * cache last used pipe for splice
1530 */
1531 struct pipe_inode_info *splice_pipe;
1532 #ifdef CONFIG_TASK_DELAY_ACCT
1533 struct task_delay_info *delays;
1534 #endif
1535 #ifdef CONFIG_FAULT_INJECTION
1536 int make_it_fail;
1537 #endif
1538 /*
1539 * when (nr_dirtied >= nr_dirtied_pause), it's time to call
1540 * balance_dirty_pages() for some dirty throttling pause
1541 */
1542 int nr_dirtied;
1543 int nr_dirtied_pause;
1544 unsigned long dirty_paused_when; /* start of a write-and-pause period */
1545
1546 #ifdef CONFIG_LATENCYTOP
1547 int latency_record_count;
1548 struct latency_record latency_record[LT_SAVECOUNT];
1549 #endif
1550 /*
1551 * time slack values; these are used to round up poll() and
1552 * select() etc timeout values. These are in nanoseconds.
1553 */
1554 unsigned long timer_slack_ns;
1555 unsigned long default_timer_slack_ns;
1556
1557 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1558 /* Index of current stored address in ret_stack */
1559 int curr_ret_stack;
1560 /* Stack of return addresses for return function tracing */
1561 struct ftrace_ret_stack *ret_stack;
1562 /* time stamp for last schedule */
1563 unsigned long long ftrace_timestamp;
1564 /*
1565 * Number of functions that haven't been traced
1566 * because of depth overrun.
1567 */
1568 atomic_t trace_overrun;
1569 /* Pause for the tracing */
1570 atomic_t tracing_graph_pause;
1571 #endif
1572 #ifdef CONFIG_TRACING
1573 /* state flags for use by tracers */
1574 unsigned long trace;
1575 /* bitmask and counter of trace recursion */
1576 unsigned long trace_recursion;
1577 #endif /* CONFIG_TRACING */
1578 #ifdef CONFIG_MEMCG /* memcg uses this to do batch job */
1579 struct memcg_batch_info {
1580 int do_batch; /* incremented when batch uncharge started */
1581 struct mem_cgroup *memcg; /* target memcg of uncharge */
1582 unsigned long nr_pages; /* uncharged usage */
1583 unsigned long memsw_nr_pages; /* uncharged mem+swap usage */
1584 } memcg_batch;
1585 #endif
1586 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1587 atomic_t ptrace_bp_refcnt;
1588 #endif
1589 #ifdef CONFIG_UPROBES
1590 struct uprobe_task *utask;
1591 #endif
1592 };
1593
1594 /* Future-safe accessor for struct task_struct's cpus_allowed. */
1595 #define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
1596
1597 /*
1598 * Priority of a process goes from 0..MAX_PRIO-1, valid RT
1599 * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
1600 * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority
1601 * values are inverted: lower p->prio value means higher priority.
1602 *
1603 * The MAX_USER_RT_PRIO value allows the actual maximum
1604 * RT priority to be separate from the value exported to
1605 * user-space. This allows kernel threads to set their
1606 * priority to a value higher than any user task. Note:
1607 * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
1608 */
1609
1610 #define MAX_USER_RT_PRIO 100
1611 #define MAX_RT_PRIO MAX_USER_RT_PRIO
1612
1613 #define MAX_PRIO (MAX_RT_PRIO + 40)
1614 #define DEFAULT_PRIO (MAX_RT_PRIO + 20)
1615
1616 static inline int rt_prio(int prio)
1617 {
1618 if (unlikely(prio < MAX_RT_PRIO))
1619 return 1;
1620 return 0;
1621 }
1622
1623 static inline int rt_task(struct task_struct *p)
1624 {
1625 return rt_prio(p->prio);
1626 }
1627
1628 static inline struct pid *task_pid(struct task_struct *task)
1629 {
1630 return task->pids[PIDTYPE_PID].pid;
1631 }
1632
1633 static inline struct pid *task_tgid(struct task_struct *task)
1634 {
1635 return task->group_leader->pids[PIDTYPE_PID].pid;
1636 }
1637
1638 /*
1639 * Without tasklist or rcu lock it is not safe to dereference
1640 * the result of task_pgrp/task_session even if task == current,
1641 * we can race with another thread doing sys_setsid/sys_setpgid.
1642 */
1643 static inline struct pid *task_pgrp(struct task_struct *task)
1644 {
1645 return task->group_leader->pids[PIDTYPE_PGID].pid;
1646 }
1647
1648 static inline struct pid *task_session(struct task_struct *task)
1649 {
1650 return task->group_leader->pids[PIDTYPE_SID].pid;
1651 }
1652
1653 struct pid_namespace;
1654
1655 /*
1656 * the helpers to get the task's different pids as they are seen
1657 * from various namespaces
1658 *
1659 * task_xid_nr() : global id, i.e. the id seen from the init namespace;
1660 * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of
1661 * current.
1662 * task_xid_nr_ns() : id seen from the ns specified;
1663 *
1664 * set_task_vxid() : assigns a virtual id to a task;
1665 *
1666 * see also pid_nr() etc in include/linux/pid.h
1667 */
1668 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
1669 struct pid_namespace *ns);
1670
1671 static inline pid_t task_pid_nr(struct task_struct *tsk)
1672 {
1673 return tsk->pid;
1674 }
1675
1676 static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
1677 struct pid_namespace *ns)
1678 {
1679 return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1680 }
1681
1682 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1683 {
1684 return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1685 }
1686
1687
1688 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1689 {
1690 return tsk->tgid;
1691 }
1692
1693 pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
1694
1695 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1696 {
1697 return pid_vnr(task_tgid(tsk));
1698 }
1699
1700
1701 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
1702 struct pid_namespace *ns)
1703 {
1704 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1705 }
1706
1707 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1708 {
1709 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1710 }
1711
1712
1713 static inline pid_t task_session_nr_ns(struct task_struct *tsk,
1714 struct pid_namespace *ns)
1715 {
1716 return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1717 }
1718
1719 static inline pid_t task_session_vnr(struct task_struct *tsk)
1720 {
1721 return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1722 }
1723
1724 /* obsolete, do not use */
1725 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1726 {
1727 return task_pgrp_nr_ns(tsk, &init_pid_ns);
1728 }
1729
1730 /**
1731 * pid_alive - check that a task structure is not stale
1732 * @p: Task structure to be checked.
1733 *
1734 * Test if a process is not yet dead (at most zombie state)
1735 * If pid_alive fails, then pointers within the task structure
1736 * can be stale and must not be dereferenced.
1737 */
1738 static inline int pid_alive(struct task_struct *p)
1739 {
1740 return p->pids[PIDTYPE_PID].pid != NULL;
1741 }
1742
1743 /**
1744 * is_global_init - check if a task structure is init
1745 * @tsk: Task structure to be checked.
1746 *
1747 * Check if a task structure is the first user space task the kernel created.
1748 */
1749 static inline int is_global_init(struct task_struct *tsk)
1750 {
1751 return tsk->pid == 1;
1752 }
1753
1754 /*
1755 * is_container_init:
1756 * check whether in the task is init in its own pid namespace.
1757 */
1758 extern int is_container_init(struct task_struct *tsk);
1759
1760 extern struct pid *cad_pid;
1761
1762 extern void free_task(struct task_struct *tsk);
1763 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
1764
1765 extern void __put_task_struct(struct task_struct *t);
1766
1767 static inline void put_task_struct(struct task_struct *t)
1768 {
1769 if (atomic_dec_and_test(&t->usage))
1770 __put_task_struct(t);
1771 }
1772
1773 extern void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st);
1774 extern void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st);
1775
1776 /*
1777 * Per process flags
1778 */
1779 #define PF_EXITING 0x00000004 /* getting shut down */
1780 #define PF_EXITPIDONE 0x00000008 /* pi exit done on shut down */
1781 #define PF_VCPU 0x00000010 /* I'm a virtual CPU */
1782 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */
1783 #define PF_FORKNOEXEC 0x00000040 /* forked but didn't exec */
1784 #define PF_MCE_PROCESS 0x00000080 /* process policy on mce errors */
1785 #define PF_SUPERPRIV 0x00000100 /* used super-user privileges */
1786 #define PF_DUMPCORE 0x00000200 /* dumped core */
1787 #define PF_SIGNALED 0x00000400 /* killed by a signal */
1788 #define PF_MEMALLOC 0x00000800 /* Allocating memory */
1789 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user noticed that RLIMIT_NPROC was exceeded */
1790 #define PF_USED_MATH 0x00002000 /* if unset the fpu must be initialized before use */
1791 #define PF_NOFREEZE 0x00008000 /* this thread should not be frozen */
1792 #define PF_FROZEN 0x00010000 /* frozen for system suspend */
1793 #define PF_FSTRANS 0x00020000 /* inside a filesystem transaction */
1794 #define PF_KSWAPD 0x00040000 /* I am kswapd */
1795 #define PF_LESS_THROTTLE 0x00100000 /* Throttle me less: I clean memory */
1796 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */
1797 #define PF_RANDOMIZE 0x00400000 /* randomize virtual address space */
1798 #define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */
1799 #define PF_SPREAD_PAGE 0x01000000 /* Spread page cache over cpuset */
1800 #define PF_SPREAD_SLAB 0x02000000 /* Spread some slab caches over cpuset */
1801 #define PF_THREAD_BOUND 0x04000000 /* Thread bound to specific cpu */
1802 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */
1803 #define PF_MEMPOLICY 0x10000000 /* Non-default NUMA mempolicy */
1804 #define PF_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */
1805 #define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezable */
1806
1807 /*
1808 * Only the _current_ task can read/write to tsk->flags, but other
1809 * tasks can access tsk->flags in readonly mode for example
1810 * with tsk_used_math (like during threaded core dumping).
1811 * There is however an exception to this rule during ptrace
1812 * or during fork: the ptracer task is allowed to write to the
1813 * child->flags of its traced child (same goes for fork, the parent
1814 * can write to the child->flags), because we're guaranteed the
1815 * child is not running and in turn not changing child->flags
1816 * at the same time the parent does it.
1817 */
1818 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1819 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1820 #define clear_used_math() clear_stopped_child_used_math(current)
1821 #define set_used_math() set_stopped_child_used_math(current)
1822 #define conditional_stopped_child_used_math(condition, child) \
1823 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1824 #define conditional_used_math(condition) \
1825 conditional_stopped_child_used_math(condition, current)
1826 #define copy_to_stopped_child_used_math(child) \
1827 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1828 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1829 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1830 #define used_math() tsk_used_math(current)
1831
1832 /*
1833 * task->jobctl flags
1834 */
1835 #define JOBCTL_STOP_SIGMASK 0xffff /* signr of the last group stop */
1836
1837 #define JOBCTL_STOP_DEQUEUED_BIT 16 /* stop signal dequeued */
1838 #define JOBCTL_STOP_PENDING_BIT 17 /* task should stop for group stop */
1839 #define JOBCTL_STOP_CONSUME_BIT 18 /* consume group stop count */
1840 #define JOBCTL_TRAP_STOP_BIT 19 /* trap for STOP */
1841 #define JOBCTL_TRAP_NOTIFY_BIT 20 /* trap for NOTIFY */
1842 #define JOBCTL_TRAPPING_BIT 21 /* switching to TRACED */
1843 #define JOBCTL_LISTENING_BIT 22 /* ptracer is listening for events */
1844
1845 #define JOBCTL_STOP_DEQUEUED (1 << JOBCTL_STOP_DEQUEUED_BIT)
1846 #define JOBCTL_STOP_PENDING (1 << JOBCTL_STOP_PENDING_BIT)
1847 #define JOBCTL_STOP_CONSUME (1 << JOBCTL_STOP_CONSUME_BIT)
1848 #define JOBCTL_TRAP_STOP (1 << JOBCTL_TRAP_STOP_BIT)
1849 #define JOBCTL_TRAP_NOTIFY (1 << JOBCTL_TRAP_NOTIFY_BIT)
1850 #define JOBCTL_TRAPPING (1 << JOBCTL_TRAPPING_BIT)
1851 #define JOBCTL_LISTENING (1 << JOBCTL_LISTENING_BIT)
1852
1853 #define JOBCTL_TRAP_MASK (JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY)
1854 #define JOBCTL_PENDING_MASK (JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK)
1855
1856 extern bool task_set_jobctl_pending(struct task_struct *task,
1857 unsigned int mask);
1858 extern void task_clear_jobctl_trapping(struct task_struct *task);
1859 extern void task_clear_jobctl_pending(struct task_struct *task,
1860 unsigned int mask);
1861
1862 #ifdef CONFIG_PREEMPT_RCU
1863
1864 #define RCU_READ_UNLOCK_BLOCKED (1 << 0) /* blocked while in RCU read-side. */
1865 #define RCU_READ_UNLOCK_NEED_QS (1 << 1) /* RCU core needs CPU response. */
1866
1867 static inline void rcu_copy_process(struct task_struct *p)
1868 {
1869 p->rcu_read_lock_nesting = 0;
1870 p->rcu_read_unlock_special = 0;
1871 #ifdef CONFIG_TREE_PREEMPT_RCU
1872 p->rcu_blocked_node = NULL;
1873 #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
1874 #ifdef CONFIG_RCU_BOOST
1875 p->rcu_boost_mutex = NULL;
1876 #endif /* #ifdef CONFIG_RCU_BOOST */
1877 INIT_LIST_HEAD(&p->rcu_node_entry);
1878 }
1879
1880 #else
1881
1882 static inline void rcu_copy_process(struct task_struct *p)
1883 {
1884 }
1885
1886 #endif
1887
1888 static inline void tsk_restore_flags(struct task_struct *task,
1889 unsigned long orig_flags, unsigned long flags)
1890 {
1891 task->flags &= ~flags;
1892 task->flags |= orig_flags & flags;
1893 }
1894
1895 #ifdef CONFIG_SMP
1896 extern void do_set_cpus_allowed(struct task_struct *p,
1897 const struct cpumask *new_mask);
1898
1899 extern int set_cpus_allowed_ptr(struct task_struct *p,
1900 const struct cpumask *new_mask);
1901 #else
1902 static inline void do_set_cpus_allowed(struct task_struct *p,
1903 const struct cpumask *new_mask)
1904 {
1905 }
1906 static inline int set_cpus_allowed_ptr(struct task_struct *p,
1907 const struct cpumask *new_mask)
1908 {
1909 if (!cpumask_test_cpu(0, new_mask))
1910 return -EINVAL;
1911 return 0;
1912 }
1913 #endif
1914
1915 #ifdef CONFIG_NO_HZ
1916 void calc_load_enter_idle(void);
1917 void calc_load_exit_idle(void);
1918 #else
1919 static inline void calc_load_enter_idle(void) { }
1920 static inline void calc_load_exit_idle(void) { }
1921 #endif /* CONFIG_NO_HZ */
1922
1923 #ifndef CONFIG_CPUMASK_OFFSTACK
1924 static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
1925 {
1926 return set_cpus_allowed_ptr(p, &new_mask);
1927 }
1928 #endif
1929
1930 /*
1931 * Do not use outside of architecture code which knows its limitations.
1932 *
1933 * sched_clock() has no promise of monotonicity or bounded drift between
1934 * CPUs, use (which you should not) requires disabling IRQs.
1935 *
1936 * Please use one of the three interfaces below.
1937 */
1938 extern unsigned long long notrace sched_clock(void);
1939 /*
1940 * See the comment in kernel/sched/clock.c
1941 */
1942 extern u64 cpu_clock(int cpu);
1943 extern u64 local_clock(void);
1944 extern u64 sched_clock_cpu(int cpu);
1945
1946
1947 extern void sched_clock_init(void);
1948
1949 #ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
1950 static inline void sched_clock_tick(void)
1951 {
1952 }
1953
1954 static inline void sched_clock_idle_sleep_event(void)
1955 {
1956 }
1957
1958 static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
1959 {
1960 }
1961 #else
1962 /*
1963 * Architectures can set this to 1 if they have specified
1964 * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig,
1965 * but then during bootup it turns out that sched_clock()
1966 * is reliable after all:
1967 */
1968 extern int sched_clock_stable;
1969
1970 extern void sched_clock_tick(void);
1971 extern void sched_clock_idle_sleep_event(void);
1972 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
1973 #endif
1974
1975 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
1976 /*
1977 * An i/f to runtime opt-in for irq time accounting based off of sched_clock.
1978 * The reason for this explicit opt-in is not to have perf penalty with
1979 * slow sched_clocks.
1980 */
1981 extern void enable_sched_clock_irqtime(void);
1982 extern void disable_sched_clock_irqtime(void);
1983 #else
1984 static inline void enable_sched_clock_irqtime(void) {}
1985 static inline void disable_sched_clock_irqtime(void) {}
1986 #endif
1987
1988 extern unsigned long long
1989 task_sched_runtime(struct task_struct *task);
1990
1991 /* sched_exec is called by processes performing an exec */
1992 #ifdef CONFIG_SMP
1993 extern void sched_exec(void);
1994 #else
1995 #define sched_exec() {}
1996 #endif
1997
1998 extern void sched_clock_idle_sleep_event(void);
1999 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
2000
2001 #ifdef CONFIG_HOTPLUG_CPU
2002 extern void idle_task_exit(void);
2003 #else
2004 static inline void idle_task_exit(void) {}
2005 #endif
2006
2007 #if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP)
2008 extern void wake_up_idle_cpu(int cpu);
2009 #else
2010 static inline void wake_up_idle_cpu(int cpu) { }
2011 #endif
2012
2013 extern unsigned int sysctl_sched_latency;
2014 extern unsigned int sysctl_sched_min_granularity;
2015 extern unsigned int sysctl_sched_wakeup_granularity;
2016 extern unsigned int sysctl_sched_child_runs_first;
2017
2018 enum sched_tunable_scaling {
2019 SCHED_TUNABLESCALING_NONE,
2020 SCHED_TUNABLESCALING_LOG,
2021 SCHED_TUNABLESCALING_LINEAR,
2022 SCHED_TUNABLESCALING_END,
2023 };
2024 extern enum sched_tunable_scaling sysctl_sched_tunable_scaling;
2025
2026 #ifdef CONFIG_SCHED_DEBUG
2027 extern unsigned int sysctl_sched_migration_cost;
2028 extern unsigned int sysctl_sched_nr_migrate;
2029 extern unsigned int sysctl_sched_time_avg;
2030 extern unsigned int sysctl_timer_migration;
2031 extern unsigned int sysctl_sched_shares_window;
2032
2033 int sched_proc_update_handler(struct ctl_table *table, int write,
2034 void __user *buffer, size_t *length,
2035 loff_t *ppos);
2036 #endif
2037 #ifdef CONFIG_SCHED_DEBUG
2038 static inline unsigned int get_sysctl_timer_migration(void)
2039 {
2040 return sysctl_timer_migration;
2041 }
2042 #else
2043 static inline unsigned int get_sysctl_timer_migration(void)
2044 {
2045 return 1;
2046 }
2047 #endif
2048 extern unsigned int sysctl_sched_rt_period;
2049 extern int sysctl_sched_rt_runtime;
2050
2051 int sched_rt_handler(struct ctl_table *table, int write,
2052 void __user *buffer, size_t *lenp,
2053 loff_t *ppos);
2054
2055 #ifdef CONFIG_SCHED_AUTOGROUP
2056 extern unsigned int sysctl_sched_autogroup_enabled;
2057
2058 extern void sched_autogroup_create_attach(struct task_struct *p);
2059 extern void sched_autogroup_detach(struct task_struct *p);
2060 extern void sched_autogroup_fork(struct signal_struct *sig);
2061 extern void sched_autogroup_exit(struct signal_struct *sig);
2062 #ifdef CONFIG_PROC_FS
2063 extern void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m);
2064 extern int proc_sched_autogroup_set_nice(struct task_struct *p, int nice);
2065 #endif
2066 #else
2067 static inline void sched_autogroup_create_attach(struct task_struct *p) { }
2068 static inline void sched_autogroup_detach(struct task_struct *p) { }
2069 static inline void sched_autogroup_fork(struct signal_struct *sig) { }
2070 static inline void sched_autogroup_exit(struct signal_struct *sig) { }
2071 #endif
2072
2073 #ifdef CONFIG_CFS_BANDWIDTH
2074 extern unsigned int sysctl_sched_cfs_bandwidth_slice;
2075 #endif
2076
2077 #ifdef CONFIG_RT_MUTEXES
2078 extern int rt_mutex_getprio(struct task_struct *p);
2079 extern void rt_mutex_setprio(struct task_struct *p, int prio);
2080 extern void rt_mutex_adjust_pi(struct task_struct *p);
2081 static inline bool tsk_is_pi_blocked(struct task_struct *tsk)
2082 {
2083 return tsk->pi_blocked_on != NULL;
2084 }
2085 #else
2086 static inline int rt_mutex_getprio(struct task_struct *p)
2087 {
2088 return p->normal_prio;
2089 }
2090 # define rt_mutex_adjust_pi(p) do { } while (0)
2091 static inline bool tsk_is_pi_blocked(struct task_struct *tsk)
2092 {
2093 return false;
2094 }
2095 #endif
2096
2097 extern bool yield_to(struct task_struct *p, bool preempt);
2098 extern void set_user_nice(struct task_struct *p, long nice);
2099 extern int task_prio(const struct task_struct *p);
2100 extern int task_nice(const struct task_struct *p);
2101 extern int can_nice(const struct task_struct *p, const int nice);
2102 extern int task_curr(const struct task_struct *p);
2103 extern int idle_cpu(int cpu);
2104 extern int sched_setscheduler(struct task_struct *, int,
2105 const struct sched_param *);
2106 extern int sched_setscheduler_nocheck(struct task_struct *, int,
2107 const struct sched_param *);
2108 extern struct task_struct *idle_task(int cpu);
2109 /**
2110 * is_idle_task - is the specified task an idle task?
2111 * @p: the task in question.
2112 */
2113 static inline bool is_idle_task(const struct task_struct *p)
2114 {
2115 return p->pid == 0;
2116 }
2117 extern struct task_struct *curr_task(int cpu);
2118 extern void set_curr_task(int cpu, struct task_struct *p);
2119
2120 void yield(void);
2121
2122 /*
2123 * The default (Linux) execution domain.
2124 */
2125 extern struct exec_domain default_exec_domain;
2126
2127 union thread_union {
2128 struct thread_info thread_info;
2129 unsigned long stack[THREAD_SIZE/sizeof(long)];
2130 };
2131
2132 #ifndef __HAVE_ARCH_KSTACK_END
2133 static inline int kstack_end(void *addr)
2134 {
2135 /* Reliable end of stack detection:
2136 * Some APM bios versions misalign the stack
2137 */
2138 return !(((unsigned long)addr+sizeof(void*)-1) & (THREAD_SIZE-sizeof(void*)));
2139 }
2140 #endif
2141
2142 extern union thread_union init_thread_union;
2143 extern struct task_struct init_task;
2144
2145 extern struct mm_struct init_mm;
2146
2147 extern struct pid_namespace init_pid_ns;
2148
2149 /*
2150 * find a task by one of its numerical ids
2151 *
2152 * find_task_by_pid_ns():
2153 * finds a task by its pid in the specified namespace
2154 * find_task_by_vpid():
2155 * finds a task by its virtual pid
2156 *
2157 * see also find_vpid() etc in include/linux/pid.h
2158 */
2159
2160 extern struct task_struct *find_task_by_vpid(pid_t nr);
2161 extern struct task_struct *find_task_by_pid_ns(pid_t nr,
2162 struct pid_namespace *ns);
2163
2164 extern void __set_special_pids(struct pid *pid);
2165
2166 /* per-UID process charging. */
2167 extern struct user_struct * alloc_uid(kuid_t);
2168 static inline struct user_struct *get_uid(struct user_struct *u)
2169 {
2170 atomic_inc(&u->__count);
2171 return u;
2172 }
2173 extern void free_uid(struct user_struct *);
2174
2175 #include <asm/current.h>
2176
2177 extern void xtime_update(unsigned long ticks);
2178
2179 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
2180 extern int wake_up_process(struct task_struct *tsk);
2181 extern void wake_up_new_task(struct task_struct *tsk);
2182 #ifdef CONFIG_SMP
2183 extern void kick_process(struct task_struct *tsk);
2184 #else
2185 static inline void kick_process(struct task_struct *tsk) { }
2186 #endif
2187 extern void sched_fork(struct task_struct *p);
2188 extern void sched_dead(struct task_struct *p);
2189
2190 extern void proc_caches_init(void);
2191 extern void flush_signals(struct task_struct *);
2192 extern void __flush_signals(struct task_struct *);
2193 extern void ignore_signals(struct task_struct *);
2194 extern void flush_signal_handlers(struct task_struct *, int force_default);
2195 extern int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info);
2196
2197 static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
2198 {
2199 unsigned long flags;
2200 int ret;
2201
2202 spin_lock_irqsave(&tsk->sighand->siglock, flags);
2203 ret = dequeue_signal(tsk, mask, info);
2204 spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
2205
2206 return ret;
2207 }
2208
2209 extern void block_all_signals(int (*notifier)(void *priv), void *priv,
2210 sigset_t *mask);
2211 extern void unblock_all_signals(void);
2212 extern void release_task(struct task_struct * p);
2213 extern int send_sig_info(int, struct siginfo *, struct task_struct *);
2214 extern int force_sigsegv(int, struct task_struct *);
2215 extern int force_sig_info(int, struct siginfo *, struct task_struct *);
2216 extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);
2217 extern int kill_pid_info(int sig, struct siginfo *info, struct pid *pid);
2218 extern int kill_pid_info_as_cred(int, struct siginfo *, struct pid *,
2219 const struct cred *, u32);
2220 extern int kill_pgrp(struct pid *pid, int sig, int priv);
2221 extern int kill_pid(struct pid *pid, int sig, int priv);
2222 extern int kill_proc_info(int, struct siginfo *, pid_t);
2223 extern __must_check bool do_notify_parent(struct task_struct *, int);
2224 extern void __wake_up_parent(struct task_struct *p, struct task_struct *parent);
2225 extern void force_sig(int, struct task_struct *);
2226 extern int send_sig(int, struct task_struct *, int);
2227 extern int zap_other_threads(struct task_struct *p);
2228 extern struct sigqueue *sigqueue_alloc(void);
2229 extern void sigqueue_free(struct sigqueue *);
2230 extern int send_sigqueue(struct sigqueue *, struct task_struct *, int group);
2231 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
2232 extern int do_sigaltstack(const stack_t __user *, stack_t __user *, unsigned long);
2233
2234 static inline void restore_saved_sigmask(void)
2235 {
2236 if (test_and_clear_restore_sigmask())
2237 __set_current_blocked(&current->saved_sigmask);
2238 }
2239
2240 static inline sigset_t *sigmask_to_save(void)
2241 {
2242 sigset_t *res = &current->blocked;
2243 if (unlikely(test_restore_sigmask()))
2244 res = &current->saved_sigmask;
2245 return res;
2246 }
2247
2248 static inline int kill_cad_pid(int sig, int priv)
2249 {
2250 return kill_pid(cad_pid, sig, priv);
2251 }
2252
2253 /* These can be the second arg to send_sig_info/send_group_sig_info. */
2254 #define SEND_SIG_NOINFO ((struct siginfo *) 0)
2255 #define SEND_SIG_PRIV ((struct siginfo *) 1)
2256 #define SEND_SIG_FORCED ((struct siginfo *) 2)
2257
2258 /*
2259 * True if we are on the alternate signal stack.
2260 */
2261 static inline int on_sig_stack(unsigned long sp)
2262 {
2263 #ifdef CONFIG_STACK_GROWSUP
2264 return sp >= current->sas_ss_sp &&
2265 sp - current->sas_ss_sp < current->sas_ss_size;
2266 #else
2267 return sp > current->sas_ss_sp &&
2268 sp - current->sas_ss_sp <= current->sas_ss_size;
2269 #endif
2270 }
2271
2272 static inline int sas_ss_flags(unsigned long sp)
2273 {
2274 return (current->sas_ss_size == 0 ? SS_DISABLE
2275 : on_sig_stack(sp) ? SS_ONSTACK : 0);
2276 }
2277
2278 /*
2279 * Routines for handling mm_structs
2280 */
2281 extern struct mm_struct * mm_alloc(void);
2282
2283 /* mmdrop drops the mm and the page tables */
2284 extern void __mmdrop(struct mm_struct *);
2285 static inline void mmdrop(struct mm_struct * mm)
2286 {
2287 if (unlikely(atomic_dec_and_test(&mm->mm_count)))
2288 __mmdrop(mm);
2289 }
2290
2291 /* mmput gets rid of the mappings and all user-space */
2292 extern void mmput(struct mm_struct *);
2293 /* Grab a reference to a task's mm, if it is not already going away */
2294 extern struct mm_struct *get_task_mm(struct task_struct *task);
2295 /*
2296 * Grab a reference to a task's mm, if it is not already going away
2297 * and ptrace_may_access with the mode parameter passed to it
2298 * succeeds.
2299 */
2300 extern struct mm_struct *mm_access(struct task_struct *task, unsigned int mode);
2301 /* Remove the current tasks stale references to the old mm_struct */
2302 extern void mm_release(struct task_struct *, struct mm_struct *);
2303 /* Allocate a new mm structure and copy contents from tsk->mm */
2304 extern struct mm_struct *dup_mm(struct task_struct *tsk);
2305
2306 extern int copy_thread(unsigned long, unsigned long, unsigned long,
2307 struct task_struct *, struct pt_regs *);
2308 extern void flush_thread(void);
2309 extern void exit_thread(void);
2310
2311 extern void exit_files(struct task_struct *);
2312 extern void __cleanup_sighand(struct sighand_struct *);
2313
2314 extern void exit_itimers(struct signal_struct *);
2315 extern void flush_itimer_signals(void);
2316
2317 extern void do_group_exit(int);
2318
2319 extern void daemonize(const char *, ...);
2320 extern int allow_signal(int);
2321 extern int disallow_signal(int);
2322
2323 extern int do_execve(const char *,
2324 const char __user * const __user *,
2325 const char __user * const __user *, struct pt_regs *);
2326 extern long do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *);
2327 struct task_struct *fork_idle(int);
2328
2329 extern void set_task_comm(struct task_struct *tsk, char *from);
2330 extern char *get_task_comm(char *to, struct task_struct *tsk);
2331
2332 #ifdef CONFIG_SMP
2333 void scheduler_ipi(void);
2334 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
2335 #else
2336 static inline void scheduler_ipi(void) { }
2337 static inline unsigned long wait_task_inactive(struct task_struct *p,
2338 long match_state)
2339 {
2340 return 1;
2341 }
2342 #endif
2343
2344 #define next_task(p) \
2345 list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
2346
2347 #define for_each_process(p) \
2348 for (p = &init_task ; (p = next_task(p)) != &init_task ; )
2349
2350 extern bool current_is_single_threaded(void);
2351
2352 /*
2353 * Careful: do_each_thread/while_each_thread is a double loop so
2354 * 'break' will not work as expected - use goto instead.
2355 */
2356 #define do_each_thread(g, t) \
2357 for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
2358
2359 #define while_each_thread(g, t) \
2360 while ((t = next_thread(t)) != g)
2361
2362 static inline int get_nr_threads(struct task_struct *tsk)
2363 {
2364 return tsk->signal->nr_threads;
2365 }
2366
2367 static inline bool thread_group_leader(struct task_struct *p)
2368 {
2369 return p->exit_signal >= 0;
2370 }
2371
2372 /* Do to the insanities of de_thread it is possible for a process
2373 * to have the pid of the thread group leader without actually being
2374 * the thread group leader. For iteration through the pids in proc
2375 * all we care about is that we have a task with the appropriate
2376 * pid, we don't actually care if we have the right task.
2377 */
2378 static inline int has_group_leader_pid(struct task_struct *p)
2379 {
2380 return p->pid == p->tgid;
2381 }
2382
2383 static inline
2384 int same_thread_group(struct task_struct *p1, struct task_struct *p2)
2385 {
2386 return p1->tgid == p2->tgid;
2387 }
2388
2389 static inline struct task_struct *next_thread(const struct task_struct *p)
2390 {
2391 return list_entry_rcu(p->thread_group.next,
2392 struct task_struct, thread_group);
2393 }
2394
2395 static inline int thread_group_empty(struct task_struct *p)
2396 {
2397 return list_empty(&p->thread_group);
2398 }
2399
2400 #define delay_group_leader(p) \
2401 (thread_group_leader(p) && !thread_group_empty(p))
2402
2403 /*
2404 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
2405 * subscriptions and synchronises with wait4(). Also used in procfs. Also
2406 * pins the final release of task.io_context. Also protects ->cpuset and
2407 * ->cgroup.subsys[]. And ->vfork_done.
2408 *
2409 * Nests both inside and outside of read_lock(&tasklist_lock).
2410 * It must not be nested with write_lock_irq(&tasklist_lock),
2411 * neither inside nor outside.
2412 */
2413 static inline void task_lock(struct task_struct *p)
2414 {
2415 spin_lock(&p->alloc_lock);
2416 }
2417
2418 static inline void task_unlock(struct task_struct *p)
2419 {
2420 spin_unlock(&p->alloc_lock);
2421 }
2422
2423 extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
2424 unsigned long *flags);
2425
2426 static inline struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
2427 unsigned long *flags)
2428 {
2429 struct sighand_struct *ret;
2430
2431 ret = __lock_task_sighand(tsk, flags);
2432 (void)__cond_lock(&tsk->sighand->siglock, ret);
2433 return ret;
2434 }
2435
2436 static inline void unlock_task_sighand(struct task_struct *tsk,
2437 unsigned long *flags)
2438 {
2439 spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
2440 }
2441
2442 #ifdef CONFIG_CGROUPS
2443 static inline void threadgroup_change_begin(struct task_struct *tsk)
2444 {
2445 down_read(&tsk->signal->group_rwsem);
2446 }
2447 static inline void threadgroup_change_end(struct task_struct *tsk)
2448 {
2449 up_read(&tsk->signal->group_rwsem);
2450 }
2451
2452 /**
2453 * threadgroup_lock - lock threadgroup
2454 * @tsk: member task of the threadgroup to lock
2455 *
2456 * Lock the threadgroup @tsk belongs to. No new task is allowed to enter
2457 * and member tasks aren't allowed to exit (as indicated by PF_EXITING) or
2458 * perform exec. This is useful for cases where the threadgroup needs to
2459 * stay stable across blockable operations.
2460 *
2461 * fork and exit paths explicitly call threadgroup_change_{begin|end}() for
2462 * synchronization. While held, no new task will be added to threadgroup
2463 * and no existing live task will have its PF_EXITING set.
2464 *
2465 * During exec, a task goes and puts its thread group through unusual
2466 * changes. After de-threading, exclusive access is assumed to resources
2467 * which are usually shared by tasks in the same group - e.g. sighand may
2468 * be replaced with a new one. Also, the exec'ing task takes over group
2469 * leader role including its pid. Exclude these changes while locked by
2470 * grabbing cred_guard_mutex which is used to synchronize exec path.
2471 */
2472 static inline void threadgroup_lock(struct task_struct *tsk)
2473 {
2474 /*
2475 * exec uses exit for de-threading nesting group_rwsem inside
2476 * cred_guard_mutex. Grab cred_guard_mutex first.
2477 */
2478 mutex_lock(&tsk->signal->cred_guard_mutex);
2479 down_write(&tsk->signal->group_rwsem);
2480 }
2481
2482 /**
2483 * threadgroup_unlock - unlock threadgroup
2484 * @tsk: member task of the threadgroup to unlock
2485 *
2486 * Reverse threadgroup_lock().
2487 */
2488 static inline void threadgroup_unlock(struct task_struct *tsk)
2489 {
2490 up_write(&tsk->signal->group_rwsem);
2491 mutex_unlock(&tsk->signal->cred_guard_mutex);
2492 }
2493 #else
2494 static inline void threadgroup_change_begin(struct task_struct *tsk) {}
2495 static inline void threadgroup_change_end(struct task_struct *tsk) {}
2496 static inline void threadgroup_lock(struct task_struct *tsk) {}
2497 static inline void threadgroup_unlock(struct task_struct *tsk) {}
2498 #endif
2499
2500 #ifndef __HAVE_THREAD_FUNCTIONS
2501
2502 #define task_thread_info(task) ((struct thread_info *)(task)->stack)
2503 #define task_stack_page(task) ((task)->stack)
2504
2505 static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
2506 {
2507 *task_thread_info(p) = *task_thread_info(org);
2508 task_thread_info(p)->task = p;
2509 }
2510
2511 static inline unsigned long *end_of_stack(struct task_struct *p)
2512 {
2513 return (unsigned long *)(task_thread_info(p) + 1);
2514 }
2515
2516 #endif
2517
2518 static inline int object_is_on_stack(void *obj)
2519 {
2520 void *stack = task_stack_page(current);
2521
2522 return (obj >= stack) && (obj < (stack + THREAD_SIZE));
2523 }
2524
2525 extern void thread_info_cache_init(void);
2526
2527 #ifdef CONFIG_DEBUG_STACK_USAGE
2528 static inline unsigned long stack_not_used(struct task_struct *p)
2529 {
2530 unsigned long *n = end_of_stack(p);
2531
2532 do { /* Skip over canary */
2533 n++;
2534 } while (!*n);
2535
2536 return (unsigned long)n - (unsigned long)end_of_stack(p);
2537 }
2538 #endif
2539
2540 /* set thread flags in other task's structures
2541 * - see asm/thread_info.h for TIF_xxxx flags available
2542 */
2543 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
2544 {
2545 set_ti_thread_flag(task_thread_info(tsk), flag);
2546 }
2547
2548 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2549 {
2550 clear_ti_thread_flag(task_thread_info(tsk), flag);
2551 }
2552
2553 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
2554 {
2555 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
2556 }
2557
2558 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
2559 {
2560 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
2561 }
2562
2563 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
2564 {
2565 return test_ti_thread_flag(task_thread_info(tsk), flag);
2566 }
2567
2568 static inline void set_tsk_need_resched(struct task_struct *tsk)
2569 {
2570 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2571 }
2572
2573 static inline void clear_tsk_need_resched(struct task_struct *tsk)
2574 {
2575 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
2576 }
2577
2578 static inline int test_tsk_need_resched(struct task_struct *tsk)
2579 {
2580 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
2581 }
2582
2583 static inline int restart_syscall(void)
2584 {
2585 set_tsk_thread_flag(current, TIF_SIGPENDING);
2586 return -ERESTARTNOINTR;
2587 }
2588
2589 static inline int signal_pending(struct task_struct *p)
2590 {
2591 return unlikely(test_tsk_thread_flag(p,TIF_SIGPENDING));
2592 }
2593
2594 static inline int __fatal_signal_pending(struct task_struct *p)
2595 {
2596 return unlikely(sigismember(&p->pending.signal, SIGKILL));
2597 }
2598
2599 static inline int fatal_signal_pending(struct task_struct *p)
2600 {
2601 return signal_pending(p) && __fatal_signal_pending(p);
2602 }
2603
2604 static inline int signal_pending_state(long state, struct task_struct *p)
2605 {
2606 if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
2607 return 0;
2608 if (!signal_pending(p))
2609 return 0;
2610
2611 return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
2612 }
2613
2614 static inline int need_resched(void)
2615 {
2616 return unlikely(test_thread_flag(TIF_NEED_RESCHED));
2617 }
2618
2619 /*
2620 * cond_resched() and cond_resched_lock(): latency reduction via
2621 * explicit rescheduling in places that are safe. The return
2622 * value indicates whether a reschedule was done in fact.
2623 * cond_resched_lock() will drop the spinlock before scheduling,
2624 * cond_resched_softirq() will enable bhs before scheduling.
2625 */
2626 extern int _cond_resched(void);
2627
2628 #define cond_resched() ({ \
2629 __might_sleep(__FILE__, __LINE__, 0); \
2630 _cond_resched(); \
2631 })
2632
2633 extern int __cond_resched_lock(spinlock_t *lock);
2634
2635 #ifdef CONFIG_PREEMPT_COUNT
2636 #define PREEMPT_LOCK_OFFSET PREEMPT_OFFSET
2637 #else
2638 #define PREEMPT_LOCK_OFFSET 0
2639 #endif
2640
2641 #define cond_resched_lock(lock) ({ \
2642 __might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET); \
2643 __cond_resched_lock(lock); \
2644 })
2645
2646 extern int __cond_resched_softirq(void);
2647
2648 #define cond_resched_softirq() ({ \
2649 __might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET); \
2650 __cond_resched_softirq(); \
2651 })
2652
2653 /*
2654 * Does a critical section need to be broken due to another
2655 * task waiting?: (technically does not depend on CONFIG_PREEMPT,
2656 * but a general need for low latency)
2657 */
2658 static inline int spin_needbreak(spinlock_t *lock)
2659 {
2660 #ifdef CONFIG_PREEMPT
2661 return spin_is_contended(lock);
2662 #else
2663 return 0;
2664 #endif
2665 }
2666
2667 /*
2668 * Thread group CPU time accounting.
2669 */
2670 void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
2671 void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
2672
2673 static inline void thread_group_cputime_init(struct signal_struct *sig)
2674 {
2675 raw_spin_lock_init(&sig->cputimer.lock);
2676 }
2677
2678 /*
2679 * Reevaluate whether the task has signals pending delivery.
2680 * Wake the task if so.
2681 * This is required every time the blocked sigset_t changes.
2682 * callers must hold sighand->siglock.
2683 */
2684 extern void recalc_sigpending_and_wake(struct task_struct *t);
2685 extern void recalc_sigpending(void);
2686
2687 extern void signal_wake_up(struct task_struct *t, int resume_stopped);
2688
2689 /*
2690 * Wrappers for p->thread_info->cpu access. No-op on UP.
2691 */
2692 #ifdef CONFIG_SMP
2693
2694 static inline unsigned int task_cpu(const struct task_struct *p)
2695 {
2696 return task_thread_info(p)->cpu;
2697 }
2698
2699 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
2700
2701 #else
2702
2703 static inline unsigned int task_cpu(const struct task_struct *p)
2704 {
2705 return 0;
2706 }
2707
2708 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
2709 {
2710 }
2711
2712 #endif /* CONFIG_SMP */
2713
2714 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
2715 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
2716
2717 extern void normalize_rt_tasks(void);
2718
2719 #ifdef CONFIG_CGROUP_SCHED
2720
2721 extern struct task_group root_task_group;
2722
2723 extern struct task_group *sched_create_group(struct task_group *parent);
2724 extern void sched_destroy_group(struct task_group *tg);
2725 extern void sched_move_task(struct task_struct *tsk);
2726 #ifdef CONFIG_FAIR_GROUP_SCHED
2727 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
2728 extern unsigned long sched_group_shares(struct task_group *tg);
2729 #endif
2730 #ifdef CONFIG_RT_GROUP_SCHED
2731 extern int sched_group_set_rt_runtime(struct task_group *tg,
2732 long rt_runtime_us);
2733 extern long sched_group_rt_runtime(struct task_group *tg);
2734 extern int sched_group_set_rt_period(struct task_group *tg,
2735 long rt_period_us);
2736 extern long sched_group_rt_period(struct task_group *tg);
2737 extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk);
2738 #endif
2739 #endif /* CONFIG_CGROUP_SCHED */
2740
2741 extern int task_can_switch_user(struct user_struct *up,
2742 struct task_struct *tsk);
2743
2744 #ifdef CONFIG_TASK_XACCT
2745 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2746 {
2747 tsk->ioac.rchar += amt;
2748 }
2749
2750 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2751 {
2752 tsk->ioac.wchar += amt;
2753 }
2754
2755 static inline void inc_syscr(struct task_struct *tsk)
2756 {
2757 tsk->ioac.syscr++;
2758 }
2759
2760 static inline void inc_syscw(struct task_struct *tsk)
2761 {
2762 tsk->ioac.syscw++;
2763 }
2764 #else
2765 static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
2766 {
2767 }
2768
2769 static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
2770 {
2771 }
2772
2773 static inline void inc_syscr(struct task_struct *tsk)
2774 {
2775 }
2776
2777 static inline void inc_syscw(struct task_struct *tsk)
2778 {
2779 }
2780 #endif
2781
2782 #ifndef TASK_SIZE_OF
2783 #define TASK_SIZE_OF(tsk) TASK_SIZE
2784 #endif
2785
2786 #ifdef CONFIG_MM_OWNER
2787 extern void mm_update_next_owner(struct mm_struct *mm);
2788 extern void mm_init_owner(struct mm_struct *mm, struct task_struct *p);
2789 #else
2790 static inline void mm_update_next_owner(struct mm_struct *mm)
2791 {
2792 }
2793
2794 static inline void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
2795 {
2796 }
2797 #endif /* CONFIG_MM_OWNER */
2798
2799 static inline unsigned long task_rlimit(const struct task_struct *tsk,
2800 unsigned int limit)
2801 {
2802 return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_cur);
2803 }
2804
2805 static inline unsigned long task_rlimit_max(const struct task_struct *tsk,
2806 unsigned int limit)
2807 {
2808 return ACCESS_ONCE(tsk->signal->rlim[limit].rlim_max);
2809 }
2810
2811 static inline unsigned long rlimit(unsigned int limit)
2812 {
2813 return task_rlimit(current, limit);
2814 }
2815
2816 static inline unsigned long rlimit_max(unsigned int limit)
2817 {
2818 return task_rlimit_max(current, limit);
2819 }
2820
2821 #endif /* __KERNEL__ */
2822
2823 #endif
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