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);
58extern void sched_dead(struct task_struct *p);
59
60void __noreturn do_task_dead(void);
61
62extern void proc_caches_init(void);
63
64extern void fork_init(void);
65
66extern void release_task(struct task_struct * p);
67
68extern int copy_thread(unsigned long, unsigned long, unsigned long,
69 struct task_struct *, unsigned long);
70
71extern void flush_thread(void);
72
73#ifdef CONFIG_HAVE_EXIT_THREAD
74extern void exit_thread(struct task_struct *tsk);
75#else
76static inline void exit_thread(struct task_struct *tsk)
77{
78}
79#endif
80extern void do_group_exit(int);
81
82extern void exit_files(struct task_struct *);
83extern void exit_itimers(struct signal_struct *);
84
85extern pid_t kernel_clone(struct kernel_clone_args *kargs);
86struct task_struct *create_io_thread(int (*fn)(void *), void *arg, int node);
87struct task_struct *fork_idle(int);
88struct mm_struct *copy_init_mm(void);
89extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
90extern long kernel_wait4(pid_t, int __user *, int, struct rusage *);
91int kernel_wait(pid_t pid, int *stat);
92
93extern void free_task(struct task_struct *tsk);
94
95/* sched_exec is called by processes performing an exec */
96#ifdef CONFIG_SMP
97extern void sched_exec(void);
98#else
99#define sched_exec() {}
100#endif
101
102static inline struct task_struct *get_task_struct(struct task_struct *t)
103{
104 refcount_inc(&t->usage);
105 return t;
106}
107
108extern void __put_task_struct(struct task_struct *t);
109
110static inline void put_task_struct(struct task_struct *t)
111{
112 if (refcount_dec_and_test(&t->usage))
113 __put_task_struct(t);
114}
115
116static inline void put_task_struct_many(struct task_struct *t, int nr)
117{
118 if (refcount_sub_and_test(nr, &t->usage))
119 __put_task_struct(t);
120}
121
122void put_task_struct_rcu_user(struct task_struct *task);
123
124#ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
125extern int arch_task_struct_size __read_mostly;
126#else
127# define arch_task_struct_size (sizeof(struct task_struct))
128#endif
129
130#ifndef CONFIG_HAVE_ARCH_THREAD_STRUCT_WHITELIST
131/*
132 * If an architecture has not declared a thread_struct whitelist we
133 * must assume something there may need to be copied to userspace.
134 */
135static inline void arch_thread_struct_whitelist(unsigned long *offset,
136 unsigned long *size)
137{
138 *offset = 0;
139 /* Handle dynamically sized thread_struct. */
140 *size = arch_task_struct_size - offsetof(struct task_struct, thread);
141}
142#endif
143
144#ifdef CONFIG_VMAP_STACK
145static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
146{
147 return t->stack_vm_area;
148}
149#else
150static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
151{
152 return NULL;
153}
154#endif
155
156/*
157 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
158 * subscriptions and synchronises with wait4(). Also used in procfs. Also
159 * pins the final release of task.io_context. Also protects ->cpuset and
160 * ->cgroup.subsys[]. And ->vfork_done.
161 *
162 * Nests both inside and outside of read_lock(&tasklist_lock).
163 * It must not be nested with write_lock_irq(&tasklist_lock),
164 * neither inside nor outside.
165 */
166static inline void task_lock(struct task_struct *p)
167{
168 spin_lock(&p->alloc_lock);
169}
170
171static inline void task_unlock(struct task_struct *p)
172{
173 spin_unlock(&p->alloc_lock);
174}
175
176#endif /* _LINUX_SCHED_TASK_H */