include/linux/sched/task.h

   1 #ifndef _LINUX_SCHED_TASK_H
   2 #define _LINUX_SCHED_TASK_H
   3
   4 /*
   5  * Interface between the scheduler and various task lifetime (fork()/exit())
   6  * functionality:
   7  */
   8
   9 #include <linux/sched.h>
  10
  11 struct task_struct;
  12 union thread_union;
  13
  14 /*
  15  * This serializes "schedule()" and also protects
  16  * the run-queue from deletions/modifications (but
  17  * _adding_ to the beginning of the run-queue has
  18  * a separate lock).
  19  */
  20 extern rwlock_t tasklist_lock;
  21 extern spinlock_t mmlist_lock;
  22
  23 extern union thread_union init_thread_union;
  24 extern struct task_struct init_task;
  25
  26 #ifdef CONFIG_PROVE_RCU
  27 extern int lockdep_tasklist_lock_is_held(void);
  28 #endif /* #ifdef CONFIG_PROVE_RCU */
  29
  30 extern asmlinkage void schedule_tail(struct task_struct *prev);
  31 extern void init_idle(struct task_struct *idle, int cpu);
  32 extern void init_idle_bootup_task(struct task_struct *idle);
  33
  34 extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
  35 extern void sched_dead(struct task_struct *p);
  36
  37 void __noreturn do_task_dead(void);
  38
  39 extern void proc_caches_init(void);
  40
  41 extern void release_task(struct task_struct * p);
  42
  43 #ifdef CONFIG_HAVE_COPY_THREAD_TLS
  44 extern int copy_thread_tls(unsigned long, unsigned long, unsigned long,
  45                         struct task_struct *, unsigned long);
  46 #else
  47 extern int copy_thread(unsigned long, unsigned long, unsigned long,
  48                         struct task_struct *);
  49
  50 /* Architectures that haven't opted into copy_thread_tls get the tls argument
  51  * via pt_regs, so ignore the tls argument passed via C. */
  52 static inline int copy_thread_tls(
  53                 unsigned long clone_flags, unsigned long sp, unsigned long arg,
  54                 struct task_struct *p, unsigned long tls)
  55 {
  56         return copy_thread(clone_flags, sp, arg, p);
  57 }
  58 #endif
  59 extern void flush_thread(void);
  60
  61 #ifdef CONFIG_HAVE_EXIT_THREAD
  62 extern void exit_thread(struct task_struct *tsk);
  63 #else
  64 static inline void exit_thread(struct task_struct *tsk)
  65 {
  66 }
  67 #endif
  68 extern void do_group_exit(int);
  69
  70 extern void exit_files(struct task_struct *);
  71 extern void exit_itimers(struct signal_struct *);
  72
  73 extern long _do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *, unsigned long);
  74 extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
  75 struct task_struct *fork_idle(int);
  76 extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
  77
  78
  79 #ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
  80 extern int arch_task_struct_size __read_mostly;
  81 #else
  82 # define arch_task_struct_size (sizeof(struct task_struct))
  83 #endif
  84
  85 #ifdef CONFIG_VMAP_STACK
  86 static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
  87 {
  88         return t->stack_vm_area;
  89 }
  90 #else
  91 static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
  92 {
  93         return NULL;
  94 }
  95 #endif
  96
  97 /*
  98  * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
  99  * subscriptions and synchronises with wait4().  Also used in procfs.  Also
 100  * pins the final release of task.io_context.  Also protects ->cpuset and
 101  * ->cgroup.subsys[]. And ->vfork_done.
 102  *
 103  * Nests both inside and outside of read_lock(&tasklist_lock).
 104  * It must not be nested with write_lock_irq(&tasklist_lock),
 105  * neither inside nor outside.
 106  */
 107 static inline void task_lock(struct task_struct *p)
 108 {
 109         spin_lock(&p->alloc_lock);
 110 }
 111
 112 static inline void task_unlock(struct task_struct *p)
 113 {
 114         spin_unlock(&p->alloc_lock);
 115 }
 116
 117 #endif /* _LINUX_SCHED_TASK_H */