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 struct cgroup *cgrp;
35 struct css_set *cset;
36};
37
38/*
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
42 * a separate lock).
43 */
44extern rwlock_t tasklist_lock;
45extern spinlock_t mmlist_lock;
46
47extern union thread_union init_thread_union;
48extern struct task_struct init_task;
49
50extern int lockdep_tasklist_lock_is_held(void);
51
52extern asmlinkage void schedule_tail(struct task_struct *prev);
53extern void init_idle(struct task_struct *idle, int cpu);
54
55extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
56extern void sched_post_fork(struct task_struct *p);
57extern void sched_dead(struct task_struct *p);
58
59void __noreturn do_task_dead(void);
60
61extern void proc_caches_init(void);
62
63extern void fork_init(void);
64
65extern void release_task(struct task_struct * p);
66
67extern int copy_thread(unsigned long, unsigned long, unsigned long,
68 struct task_struct *, unsigned long);
69
70extern void flush_thread(void);
71
72#ifdef CONFIG_HAVE_EXIT_THREAD
73extern void exit_thread(struct task_struct *tsk);
74#else
75static inline void exit_thread(struct task_struct *tsk)
76{
77}
78#endif
79extern void do_group_exit(int);
80
81extern void exit_files(struct task_struct *);
82extern void exit_itimers(struct signal_struct *);
83
84extern pid_t kernel_clone(struct kernel_clone_args *kargs);
85struct task_struct *fork_idle(int);
86struct mm_struct *copy_init_mm(void);
87extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
88extern long kernel_wait4(pid_t, int __user *, int, struct rusage *);
89int kernel_wait(pid_t pid, int *stat);
90
91extern void free_task(struct task_struct *tsk);
92
93/* sched_exec is called by processes performing an exec */
94#ifdef CONFIG_SMP
95extern void sched_exec(void);
96#else
97#define sched_exec() {}
98#endif
99
100static inline struct task_struct *get_task_struct(struct task_struct *t)
101{
102 refcount_inc(&t->usage);
103 return t;
104}
105
106extern void __put_task_struct(struct task_struct *t);
107
108static inline void put_task_struct(struct task_struct *t)
109{
110 if (refcount_dec_and_test(&t->usage))
111 __put_task_struct(t);
112}
113
114static inline void put_task_struct_many(struct task_struct *t, int nr)
115{
116 if (refcount_sub_and_test(nr, &t->usage))
117 __put_task_struct(t);
118}
119
120void put_task_struct_rcu_user(struct task_struct *task);
121
122#ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
123extern int arch_task_struct_size __read_mostly;
124#else
125# define arch_task_struct_size (sizeof(struct task_struct))
126#endif
127
128#ifndef CONFIG_HAVE_ARCH_THREAD_STRUCT_WHITELIST
129/*
130 * If an architecture has not declared a thread_struct whitelist we
131 * must assume something there may need to be copied to userspace.
132 */
133static inline void arch_thread_struct_whitelist(unsigned long *offset,
134 unsigned long *size)
135{
136 *offset = 0;
137 /* Handle dynamically sized thread_struct. */
138 *size = arch_task_struct_size - offsetof(struct task_struct, thread);
139}
140#endif
141
142#ifdef CONFIG_VMAP_STACK
143static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
144{
145 return t->stack_vm_area;
146}
147#else
148static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
149{
150 return NULL;
151}
152#endif
153
154/*
155 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
156 * subscriptions and synchronises with wait4(). Also used in procfs. Also
157 * pins the final release of task.io_context. Also protects ->cpuset and
158 * ->cgroup.subsys[]. And ->vfork_done.
159 *
160 * Nests both inside and outside of read_lock(&tasklist_lock).
161 * It must not be nested with write_lock_irq(&tasklist_lock),
162 * neither inside nor outside.
163 */
164static inline void task_lock(struct task_struct *p)
165{
166 spin_lock(&p->alloc_lock);
167}
168
169static inline void task_unlock(struct task_struct *p)
170{
171 spin_unlock(&p->alloc_lock);
172}
173
174#endif /* _LINUX_SCHED_TASK_H */