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>
11 #include <linux/uaccess.h>
18 /* All the bits taken by the old clone syscall. */
19 #define CLONE_LEGACY_FLAGS 0xffffffffULL
21 struct kernel_clone_args {
24 int __user *child_tid;
25 int __user *parent_tid;
28 unsigned long stack_size;
31 /* Number of elements in *set_tid */
40 * This serializes "schedule()" and also protects
41 * the run-queue from deletions/modifications (but
42 * _adding_ to the beginning of the run-queue has
45 extern rwlock_t tasklist_lock;
46 extern spinlock_t mmlist_lock;
48 extern union thread_union init_thread_union;
49 extern struct task_struct init_task;
51 extern int lockdep_tasklist_lock_is_held(void);
53 extern asmlinkage void schedule_tail(struct task_struct *prev);
54 extern void init_idle(struct task_struct *idle, int cpu);
56 extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
57 extern void sched_cgroup_fork(struct task_struct *p, struct kernel_clone_args *kargs);
58 extern void sched_post_fork(struct task_struct *p);
59 extern void sched_dead(struct task_struct *p);
61 void __noreturn do_task_dead(void);
63 extern void proc_caches_init(void);
65 extern void fork_init(void);
67 extern void release_task(struct task_struct * p);
69 extern int copy_thread(unsigned long, unsigned long, unsigned long,
70 struct task_struct *, unsigned long);
72 extern void flush_thread(void);
74 #ifdef CONFIG_HAVE_EXIT_THREAD
75 extern void exit_thread(struct task_struct *tsk);
77 static inline void exit_thread(struct task_struct *tsk)
81 extern void do_group_exit(int);
83 extern void exit_files(struct task_struct *);
84 extern void exit_itimers(struct signal_struct *);
86 extern pid_t kernel_clone(struct kernel_clone_args *kargs);
87 struct task_struct *create_io_thread(int (*fn)(void *), void *arg, int node);
88 struct task_struct *fork_idle(int);
89 struct mm_struct *copy_init_mm(void);
90 extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
91 extern long kernel_wait4(pid_t, int __user *, int, struct rusage *);
92 int kernel_wait(pid_t pid, int *stat);
94 extern void free_task(struct task_struct *tsk);
96 /* sched_exec is called by processes performing an exec */
98 extern void sched_exec(void);
100 #define sched_exec() {}
103 static inline struct task_struct *get_task_struct(struct task_struct *t)
105 refcount_inc(&t->usage);
109 extern void __put_task_struct(struct task_struct *t);
111 static inline void put_task_struct(struct task_struct *t)
113 if (refcount_dec_and_test(&t->usage))
114 __put_task_struct(t);
117 static inline void put_task_struct_many(struct task_struct *t, int nr)
119 if (refcount_sub_and_test(nr, &t->usage))
120 __put_task_struct(t);
123 void put_task_struct_rcu_user(struct task_struct *task);
125 #ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
126 extern int arch_task_struct_size __read_mostly;
128 # define arch_task_struct_size (sizeof(struct task_struct))
131 #ifndef CONFIG_HAVE_ARCH_THREAD_STRUCT_WHITELIST
133 * If an architecture has not declared a thread_struct whitelist we
134 * must assume something there may need to be copied to userspace.
136 static inline void arch_thread_struct_whitelist(unsigned long *offset,
140 /* Handle dynamically sized thread_struct. */
141 *size = arch_task_struct_size - offsetof(struct task_struct, thread);
145 #ifdef CONFIG_VMAP_STACK
146 static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
148 return t->stack_vm_area;
151 static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
158 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
159 * subscriptions and synchronises with wait4(). Also used in procfs. Also
160 * pins the final release of task.io_context. Also protects ->cpuset and
161 * ->cgroup.subsys[]. And ->vfork_done. And ->sysvshm.shm_clist.
163 * Nests both inside and outside of read_lock(&tasklist_lock).
164 * It must not be nested with write_lock_irq(&tasklist_lock),
165 * neither inside nor outside.
167 static inline void task_lock(struct task_struct *p)
169 spin_lock(&p->alloc_lock);
172 static inline void task_unlock(struct task_struct *p)
174 spin_unlock(&p->alloc_lock);
177 #endif /* _LINUX_SCHED_TASK_H */