Linux kernel mirror (for testing)
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linux
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_SCHED_TASK_H
3#define _LINUX_SCHED_TASK_H
4
5/*
6 * Interface between the scheduler and various task lifetime (fork()/exit())
7 * functionality:
8 */
9
10#include <linux/sched.h>
11#include <linux/uaccess.h>
12
13struct task_struct;
14struct rusage;
15union thread_union;
16struct css_set;
17
18/* All the bits taken by the old clone syscall. */
19#define CLONE_LEGACY_FLAGS 0xffffffffULL
20
21struct kernel_clone_args {
22 u64 flags;
23 int __user *pidfd;
24 int __user *child_tid;
25 int __user *parent_tid;
26 int exit_signal;
27 unsigned long stack;
28 unsigned long stack_size;
29 unsigned long tls;
30 pid_t *set_tid;
31 /* Number of elements in *set_tid */
32 size_t set_tid_size;
33 int cgroup;
34 int io_thread;
35 struct cgroup *cgrp;
36 struct css_set *cset;
37};
38
39/*
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
43 * a separate lock).
44 */
45extern rwlock_t tasklist_lock;
46extern spinlock_t mmlist_lock;
47
48extern union thread_union init_thread_union;
49extern struct task_struct init_task;
50
51extern int lockdep_tasklist_lock_is_held(void);
52
53extern asmlinkage void schedule_tail(struct task_struct *prev);
54extern void init_idle(struct task_struct *idle, int cpu);
55
56extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
57extern void sched_post_fork(struct task_struct *p,
58 struct kernel_clone_args *kargs);
59extern void sched_dead(struct task_struct *p);
60
61void __noreturn do_task_dead(void);
62
63extern void proc_caches_init(void);
64
65extern void fork_init(void);
66
67extern void release_task(struct task_struct * p);
68
69extern int copy_thread(unsigned long, unsigned long, unsigned long,
70 struct task_struct *, unsigned long);
71
72extern void flush_thread(void);
73
74#ifdef CONFIG_HAVE_EXIT_THREAD
75extern void exit_thread(struct task_struct *tsk);
76#else
77static inline void exit_thread(struct task_struct *tsk)
78{
79}
80#endif
81extern void do_group_exit(int);
82
83extern void exit_files(struct task_struct *);
84extern void exit_itimers(struct signal_struct *);
85
86extern pid_t kernel_clone(struct kernel_clone_args *kargs);
87struct task_struct *create_io_thread(int (*fn)(void *), void *arg, int node);
88struct task_struct *fork_idle(int);
89struct mm_struct *copy_init_mm(void);
90extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
91extern long kernel_wait4(pid_t, int __user *, int, struct rusage *);
92int kernel_wait(pid_t pid, int *stat);
93
94extern void free_task(struct task_struct *tsk);
95
96/* sched_exec is called by processes performing an exec */
97#ifdef CONFIG_SMP
98extern void sched_exec(void);
99#else
100#define sched_exec() {}
101#endif
102
103static inline struct task_struct *get_task_struct(struct task_struct *t)
104{
105 refcount_inc(&t->usage);
106 return t;
107}
108
109extern void __put_task_struct(struct task_struct *t);
110
111static inline void put_task_struct(struct task_struct *t)
112{
113 if (refcount_dec_and_test(&t->usage))
114 __put_task_struct(t);
115}
116
117static inline void put_task_struct_many(struct task_struct *t, int nr)
118{
119 if (refcount_sub_and_test(nr, &t->usage))
120 __put_task_struct(t);
121}
122
123void put_task_struct_rcu_user(struct task_struct *task);
124
125#ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
126extern int arch_task_struct_size __read_mostly;
127#else
128# define arch_task_struct_size (sizeof(struct task_struct))
129#endif
130
131#ifndef CONFIG_HAVE_ARCH_THREAD_STRUCT_WHITELIST
132/*
133 * If an architecture has not declared a thread_struct whitelist we
134 * must assume something there may need to be copied to userspace.
135 */
136static inline void arch_thread_struct_whitelist(unsigned long *offset,
137 unsigned long *size)
138{
139 *offset = 0;
140 /* Handle dynamically sized thread_struct. */
141 *size = arch_task_struct_size - offsetof(struct task_struct, thread);
142}
143#endif
144
145#ifdef CONFIG_VMAP_STACK
146static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
147{
148 return t->stack_vm_area;
149}
150#else
151static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
152{
153 return NULL;
154}
155#endif
156
157/*
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.
162 *
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.
166 */
167static inline void task_lock(struct task_struct *p)
168{
169 spin_lock(&p->alloc_lock);
170}
171
172static inline void task_unlock(struct task_struct *p)
173{
174 spin_unlock(&p->alloc_lock);
175}
176
177#endif /* _LINUX_SCHED_TASK_H */