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 */
39 * This serializes "schedule()" and also protects
40 * the run-queue from deletions/modifications (but
41 * _adding_ to the beginning of the run-queue has
44 extern rwlock_t tasklist_lock;
45 extern spinlock_t mmlist_lock;
47 extern union thread_union init_thread_union;
48 extern struct task_struct init_task;
50 #ifdef CONFIG_PROVE_RCU
51 extern int lockdep_tasklist_lock_is_held(void);
52 #endif /* #ifdef CONFIG_PROVE_RCU */
54 extern asmlinkage void schedule_tail(struct task_struct *prev);
55 extern void init_idle(struct task_struct *idle, int cpu);
57 extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
58 extern void sched_dead(struct task_struct *p);
60 void __noreturn do_task_dead(void);
62 extern void proc_caches_init(void);
64 extern void fork_init(void);
66 extern void release_task(struct task_struct * p);
68 #ifdef CONFIG_HAVE_COPY_THREAD_TLS
69 extern int copy_thread_tls(unsigned long, unsigned long, unsigned long,
70 struct task_struct *, unsigned long);
72 extern int copy_thread(unsigned long, unsigned long, unsigned long,
73 struct task_struct *);
75 /* Architectures that haven't opted into copy_thread_tls get the tls argument
76 * via pt_regs, so ignore the tls argument passed via C. */
77 static inline int copy_thread_tls(
78 unsigned long clone_flags, unsigned long sp, unsigned long arg,
79 struct task_struct *p, unsigned long tls)
81 return copy_thread(clone_flags, sp, arg, p);
84 extern void flush_thread(void);
86 #ifdef CONFIG_HAVE_EXIT_THREAD
87 extern void exit_thread(struct task_struct *tsk);
89 static inline void exit_thread(struct task_struct *tsk)
93 extern void do_group_exit(int);
95 extern void exit_files(struct task_struct *);
96 extern void exit_itimers(struct signal_struct *);
98 extern long _do_fork(struct kernel_clone_args *kargs);
99 extern bool legacy_clone_args_valid(const struct kernel_clone_args *kargs);
100 extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
101 struct task_struct *fork_idle(int);
102 struct mm_struct *copy_init_mm(void);
103 extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
104 extern long kernel_wait4(pid_t, int __user *, int, struct rusage *);
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 void put_task_struct_rcu_user(struct task_struct *task);
131 #ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
132 extern int arch_task_struct_size __read_mostly;
134 # define arch_task_struct_size (sizeof(struct task_struct))
137 #ifndef CONFIG_HAVE_ARCH_THREAD_STRUCT_WHITELIST
139 * If an architecture has not declared a thread_struct whitelist we
140 * must assume something there may need to be copied to userspace.
142 static inline void arch_thread_struct_whitelist(unsigned long *offset,
146 /* Handle dynamically sized thread_struct. */
147 *size = arch_task_struct_size - offsetof(struct task_struct, thread);
151 #ifdef CONFIG_VMAP_STACK
152 static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
154 return t->stack_vm_area;
157 static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
164 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
165 * subscriptions and synchronises with wait4(). Also used in procfs. Also
166 * pins the final release of task.io_context. Also protects ->cpuset and
167 * ->cgroup.subsys[]. And ->vfork_done.
169 * Nests both inside and outside of read_lock(&tasklist_lock).
170 * It must not be nested with write_lock_irq(&tasklist_lock),
171 * neither inside nor outside.
173 static inline void task_lock(struct task_struct *p)
175 spin_lock(&p->alloc_lock);
178 static inline void task_unlock(struct task_struct *p)
180 spin_unlock(&p->alloc_lock);
183 #endif /* _LINUX_SCHED_TASK_H */