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>
17 /* All the bits taken by the old clone syscall. */
18 #define CLONE_LEGACY_FLAGS 0xffffffffULL
20 struct kernel_clone_args {
23 int __user *child_tid;
24 int __user *parent_tid;
27 unsigned long stack_size;
30 /* Number of elements in *set_tid */
35 * This serializes "schedule()" and also protects
36 * the run-queue from deletions/modifications (but
37 * _adding_ to the beginning of the run-queue has
40 extern rwlock_t tasklist_lock;
41 extern spinlock_t mmlist_lock;
43 extern union thread_union init_thread_union;
44 extern struct task_struct init_task;
46 #ifdef CONFIG_PROVE_RCU
47 extern int lockdep_tasklist_lock_is_held(void);
48 #endif /* #ifdef CONFIG_PROVE_RCU */
50 extern asmlinkage void schedule_tail(struct task_struct *prev);
51 extern void init_idle(struct task_struct *idle, int cpu);
53 extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
54 extern void sched_dead(struct task_struct *p);
56 void __noreturn do_task_dead(void);
58 extern void proc_caches_init(void);
60 extern void fork_init(void);
62 extern void release_task(struct task_struct * p);
64 #ifdef CONFIG_HAVE_COPY_THREAD_TLS
65 extern int copy_thread_tls(unsigned long, unsigned long, unsigned long,
66 struct task_struct *, unsigned long);
68 extern int copy_thread(unsigned long, unsigned long, unsigned long,
69 struct task_struct *);
71 /* Architectures that haven't opted into copy_thread_tls get the tls argument
72 * via pt_regs, so ignore the tls argument passed via C. */
73 static inline int copy_thread_tls(
74 unsigned long clone_flags, unsigned long sp, unsigned long arg,
75 struct task_struct *p, unsigned long tls)
77 return copy_thread(clone_flags, sp, arg, p);
80 extern void flush_thread(void);
82 #ifdef CONFIG_HAVE_EXIT_THREAD
83 extern void exit_thread(struct task_struct *tsk);
85 static inline void exit_thread(struct task_struct *tsk)
89 extern void do_group_exit(int);
91 extern void exit_files(struct task_struct *);
92 extern void exit_itimers(struct signal_struct *);
94 extern long _do_fork(struct kernel_clone_args *kargs);
95 extern bool legacy_clone_args_valid(const struct kernel_clone_args *kargs);
96 extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
97 struct task_struct *fork_idle(int);
98 struct mm_struct *copy_init_mm(void);
99 extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
100 extern long kernel_wait4(pid_t, int __user *, int, struct rusage *);
102 extern void free_task(struct task_struct *tsk);
104 /* sched_exec is called by processes performing an exec */
106 extern void sched_exec(void);
108 #define sched_exec() {}
111 static inline struct task_struct *get_task_struct(struct task_struct *t)
113 refcount_inc(&t->usage);
117 extern void __put_task_struct(struct task_struct *t);
119 static inline void put_task_struct(struct task_struct *t)
121 if (refcount_dec_and_test(&t->usage))
122 __put_task_struct(t);
125 void put_task_struct_rcu_user(struct task_struct *task);
127 #ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
128 extern int arch_task_struct_size __read_mostly;
130 # define arch_task_struct_size (sizeof(struct task_struct))
133 #ifndef CONFIG_HAVE_ARCH_THREAD_STRUCT_WHITELIST
135 * If an architecture has not declared a thread_struct whitelist we
136 * must assume something there may need to be copied to userspace.
138 static inline void arch_thread_struct_whitelist(unsigned long *offset,
142 /* Handle dynamically sized thread_struct. */
143 *size = arch_task_struct_size - offsetof(struct task_struct, thread);
147 #ifdef CONFIG_VMAP_STACK
148 static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
150 return t->stack_vm_area;
153 static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
160 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
161 * subscriptions and synchronises with wait4(). Also used in procfs. Also
162 * pins the final release of task.io_context. Also protects ->cpuset and
163 * ->cgroup.subsys[]. And ->vfork_done.
165 * Nests both inside and outside of read_lock(&tasklist_lock).
166 * It must not be nested with write_lock_irq(&tasklist_lock),
167 * neither inside nor outside.
169 static inline void task_lock(struct task_struct *p)
171 spin_lock(&p->alloc_lock);
174 static inline void task_unlock(struct task_struct *p)
176 spin_unlock(&p->alloc_lock);
179 #endif /* _LINUX_SCHED_TASK_H */