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;
34 unsigned long stack_size;
37 /* Number of elements in *set_tid */
48 * This serializes "schedule()" and also protects
49 * the run-queue from deletions/modifications (but
50 * _adding_ to the beginning of the run-queue has
53 extern rwlock_t tasklist_lock;
54 extern spinlock_t mmlist_lock;
56 extern union thread_union init_thread_union;
57 extern struct task_struct init_task;
59 extern int lockdep_tasklist_lock_is_held(void);
61 extern asmlinkage void schedule_tail(struct task_struct *prev);
62 extern void init_idle(struct task_struct *idle, int cpu);
64 extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
65 extern void sched_cgroup_fork(struct task_struct *p, struct kernel_clone_args *kargs);
66 extern void sched_post_fork(struct task_struct *p);
67 extern void sched_dead(struct task_struct *p);
69 void __noreturn do_task_dead(void);
70 void __noreturn make_task_dead(int signr);
72 extern void mm_cache_init(void);
73 extern void proc_caches_init(void);
75 extern void fork_init(void);
77 extern void release_task(struct task_struct * p);
79 extern int copy_thread(struct task_struct *, const struct kernel_clone_args *);
81 extern void flush_thread(void);
83 #ifdef CONFIG_HAVE_EXIT_THREAD
84 extern void exit_thread(struct task_struct *tsk);
86 static inline void exit_thread(struct task_struct *tsk)
90 extern __noreturn void do_group_exit(int);
92 extern void exit_files(struct task_struct *);
93 extern void exit_itimers(struct task_struct *);
95 extern pid_t kernel_clone(struct kernel_clone_args *kargs);
96 struct task_struct *copy_process(struct pid *pid, int trace, int node,
97 struct kernel_clone_args *args);
98 struct task_struct *create_io_thread(int (*fn)(void *), void *arg, int node);
99 struct task_struct *fork_idle(int);
100 extern pid_t kernel_thread(int (*fn)(void *), void *arg, const char *name,
101 unsigned long flags);
102 extern pid_t user_mode_thread(int (*fn)(void *), void *arg, unsigned long flags);
103 extern long kernel_wait4(pid_t, int __user *, int, struct rusage *);
104 int kernel_wait(pid_t pid, int *stat);
106 extern void free_task(struct task_struct *tsk);
108 /* sched_exec is called by processes performing an exec */
110 extern void sched_exec(void);
112 #define sched_exec() {}
115 static inline struct task_struct *get_task_struct(struct task_struct *t)
117 refcount_inc(&t->usage);
121 extern void __put_task_struct(struct task_struct *t);
123 static inline void put_task_struct(struct task_struct *t)
125 if (refcount_dec_and_test(&t->usage))
126 __put_task_struct(t);
129 static inline void put_task_struct_many(struct task_struct *t, int nr)
131 if (refcount_sub_and_test(nr, &t->usage))
132 __put_task_struct(t);
135 void put_task_struct_rcu_user(struct task_struct *task);
137 /* Free all architecture-specific resources held by a thread. */
138 void release_thread(struct task_struct *dead_task);
140 #ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
141 extern int arch_task_struct_size __read_mostly;
143 # define arch_task_struct_size (sizeof(struct task_struct))
146 #ifndef CONFIG_HAVE_ARCH_THREAD_STRUCT_WHITELIST
148 * If an architecture has not declared a thread_struct whitelist we
149 * must assume something there may need to be copied to userspace.
151 static inline void arch_thread_struct_whitelist(unsigned long *offset,
155 /* Handle dynamically sized thread_struct. */
156 *size = arch_task_struct_size - offsetof(struct task_struct, thread);
160 #ifdef CONFIG_VMAP_STACK
161 static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
163 return t->stack_vm_area;
166 static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
173 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
174 * subscriptions and synchronises with wait4(). Also used in procfs. Also
175 * pins the final release of task.io_context. Also protects ->cpuset and
176 * ->cgroup.subsys[]. And ->vfork_done. And ->sysvshm.shm_clist.
178 * Nests both inside and outside of read_lock(&tasklist_lock).
179 * It must not be nested with write_lock_irq(&tasklist_lock),
180 * neither inside nor outside.
182 static inline void task_lock(struct task_struct *p)
184 spin_lock(&p->alloc_lock);
187 static inline void task_unlock(struct task_struct *p)
189 spin_unlock(&p->alloc_lock);
192 #endif /* _LINUX_SCHED_TASK_H */