1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_SCHED_TASK_H
3 #define _LINUX_SCHED_TASK_H
6 * Interface between the scheduler and various task lifetime (fork()/exit())
10 #include <linux/sched.h>
17 * This serializes "schedule()" and also protects
18 * the run-queue from deletions/modifications (but
19 * _adding_ to the beginning of the run-queue has
22 extern rwlock_t tasklist_lock;
23 extern spinlock_t mmlist_lock;
25 extern union thread_union init_thread_union;
26 extern struct task_struct init_task;
28 #ifdef CONFIG_PROVE_RCU
29 extern int lockdep_tasklist_lock_is_held(void);
30 #endif /* #ifdef CONFIG_PROVE_RCU */
32 extern asmlinkage void schedule_tail(struct task_struct *prev);
33 extern void init_idle(struct task_struct *idle, int cpu);
35 extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
36 extern void sched_dead(struct task_struct *p);
38 void __noreturn do_task_dead(void);
40 extern void proc_caches_init(void);
42 extern void fork_init(void);
44 extern void release_task(struct task_struct * p);
46 #ifdef CONFIG_HAVE_COPY_THREAD_TLS
47 extern int copy_thread_tls(unsigned long, unsigned long, unsigned long,
48 struct task_struct *, unsigned long);
50 extern int copy_thread(unsigned long, unsigned long, unsigned long,
51 struct task_struct *);
53 /* Architectures that haven't opted into copy_thread_tls get the tls argument
54 * via pt_regs, so ignore the tls argument passed via C. */
55 static inline int copy_thread_tls(
56 unsigned long clone_flags, unsigned long sp, unsigned long arg,
57 struct task_struct *p, unsigned long tls)
59 return copy_thread(clone_flags, sp, arg, p);
62 extern void flush_thread(void);
64 #ifdef CONFIG_HAVE_EXIT_THREAD
65 extern void exit_thread(struct task_struct *tsk);
67 static inline void exit_thread(struct task_struct *tsk)
71 extern void do_group_exit(int);
73 extern void exit_files(struct task_struct *);
74 extern void exit_itimers(struct signal_struct *);
76 extern long _do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *, unsigned long);
77 extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
78 struct task_struct *fork_idle(int);
79 extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
80 extern long kernel_wait4(pid_t, int __user *, int, struct rusage *);
82 extern void free_task(struct task_struct *tsk);
84 /* sched_exec is called by processes performing an exec */
86 extern void sched_exec(void);
88 #define sched_exec() {}
91 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
93 extern void __put_task_struct(struct task_struct *t);
95 static inline void put_task_struct(struct task_struct *t)
97 if (atomic_dec_and_test(&t->usage))
101 struct task_struct *task_rcu_dereference(struct task_struct **ptask);
103 #ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
104 extern int arch_task_struct_size __read_mostly;
106 # define arch_task_struct_size (sizeof(struct task_struct))
109 #ifndef CONFIG_HAVE_ARCH_THREAD_STRUCT_WHITELIST
111 * If an architecture has not declared a thread_struct whitelist we
112 * must assume something there may need to be copied to userspace.
114 static inline void arch_thread_struct_whitelist(unsigned long *offset,
118 /* Handle dynamically sized thread_struct. */
119 *size = arch_task_struct_size - offsetof(struct task_struct, thread);
123 #ifdef CONFIG_VMAP_STACK
124 static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
126 return t->stack_vm_area;
129 static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
136 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
137 * subscriptions and synchronises with wait4(). Also used in procfs. Also
138 * pins the final release of task.io_context. Also protects ->cpuset and
139 * ->cgroup.subsys[]. And ->vfork_done. And ->sysvshm.shm_clist.
141 * Nests both inside and outside of read_lock(&tasklist_lock).
142 * It must not be nested with write_lock_irq(&tasklist_lock),
143 * neither inside nor outside.
145 static inline void task_lock(struct task_struct *p)
147 spin_lock(&p->alloc_lock);
150 static inline void task_unlock(struct task_struct *p)
152 spin_unlock(&p->alloc_lock);
155 #endif /* _LINUX_SCHED_TASK_H */