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 extern void free_task(struct task_struct *tsk); 79 80 /* sched_exec is called by processes performing an exec */ 81 #ifdef CONFIG_SMP 82 extern void sched_exec(void); 83 #else 84 #define sched_exec() {} 85 #endif 86 87 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0) 88 89 extern void __put_task_struct(struct task_struct *t); 90 91 static inline void put_task_struct(struct task_struct *t) 92 { 93 if (atomic_dec_and_test(&t->usage)) 94 __put_task_struct(t); 95 } 96 97 struct task_struct *task_rcu_dereference(struct task_struct **ptask); 98 struct task_struct *try_get_task_struct(struct task_struct **ptask); 99 100 101 #ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT 102 extern int arch_task_struct_size __read_mostly; 103 #else 104 # define arch_task_struct_size (sizeof(struct task_struct)) 105 #endif 106 107 #ifdef CONFIG_VMAP_STACK 108 static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t) 109 { 110 return t->stack_vm_area; 111 } 112 #else 113 static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t) 114 { 115 return NULL; 116 } 117 #endif 118 119 /* 120 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring 121 * subscriptions and synchronises with wait4(). Also used in procfs. Also 122 * pins the final release of task.io_context. Also protects ->cpuset and 123 * ->cgroup.subsys[]. And ->vfork_done. 124 * 125 * Nests both inside and outside of read_lock(&tasklist_lock). 126 * It must not be nested with write_lock_irq(&tasklist_lock), 127 * neither inside nor outside. 128 */ 129 static inline void task_lock(struct task_struct *p) 130 { 131 spin_lock(&p->alloc_lock); 132 } 133 134 static inline void task_unlock(struct task_struct *p) 135 { 136 spin_unlock(&p->alloc_lock); 137 } 138 139 #endif /* _LINUX_SCHED_TASK_H */ 140