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_cgroup_fork(struct task_struct *p, struct kernel_clone_args *kargs);
58extern void sched_post_fork(struct task_struct *p);
59extern void sched_dead(struct task_struct *p);
60
61void __noreturn do_task_dead(void);
62void __noreturn make_task_dead(int signr);
63
64extern void proc_caches_init(void);
65
66extern void fork_init(void);
67
68extern void release_task(struct task_struct * p);
69
70extern int copy_thread(unsigned long, unsigned long, unsigned long,
71 struct task_struct *, unsigned long);
72
73extern void flush_thread(void);
74
75#ifdef CONFIG_HAVE_EXIT_THREAD
76extern void exit_thread(struct task_struct *tsk);
77#else
78static inline void exit_thread(struct task_struct *tsk)
79{
80}
81#endif
82extern __noreturn void do_group_exit(int);
83
84extern void exit_files(struct task_struct *);
85extern void exit_itimers(struct signal_struct *);
86
87extern pid_t kernel_clone(struct kernel_clone_args *kargs);
88struct task_struct *create_io_thread(int (*fn)(void *), void *arg, int node);
89struct task_struct *fork_idle(int);
90struct mm_struct *copy_init_mm(void);
91extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
92extern long kernel_wait4(pid_t, int __user *, int, struct rusage *);
93int kernel_wait(pid_t pid, int *stat);
94
95extern void free_task(struct task_struct *tsk);
96
97/* sched_exec is called by processes performing an exec */
98#ifdef CONFIG_SMP
99extern void sched_exec(void);
100#else
101#define sched_exec() {}
102#endif
103
104static inline struct task_struct *get_task_struct(struct task_struct *t)
105{
106 refcount_inc(&t->usage);
107 return t;
108}
109
110extern void __put_task_struct(struct task_struct *t);
111
112static inline void put_task_struct(struct task_struct *t)
113{
114 if (refcount_dec_and_test(&t->usage))
115 __put_task_struct(t);
116}
117
118static inline void put_task_struct_many(struct task_struct *t, int nr)
119{
120 if (refcount_sub_and_test(nr, &t->usage))
121 __put_task_struct(t);
122}
123
124void put_task_struct_rcu_user(struct task_struct *task);
125
126#ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
127extern int arch_task_struct_size __read_mostly;
128#else
129# define arch_task_struct_size (sizeof(struct task_struct))
130#endif
131
132#ifndef CONFIG_HAVE_ARCH_THREAD_STRUCT_WHITELIST
133/*
134 * If an architecture has not declared a thread_struct whitelist we
135 * must assume something there may need to be copied to userspace.
136 */
137static inline void arch_thread_struct_whitelist(unsigned long *offset,
138 unsigned long *size)
139{
140 *offset = 0;
141 /* Handle dynamically sized thread_struct. */
142 *size = arch_task_struct_size - offsetof(struct task_struct, thread);
143}
144#endif
145
146#ifdef CONFIG_VMAP_STACK
147static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
148{
149 return t->stack_vm_area;
150}
151#else
152static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
153{
154 return NULL;
155}
156#endif
157
158/*
159 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
160 * subscriptions and synchronises with wait4(). Also used in procfs. Also
161 * pins the final release of task.io_context. Also protects ->cpuset and
162 * ->cgroup.subsys[]. And ->vfork_done. And ->sysvshm.shm_clist.
163 *
164 * Nests both inside and outside of read_lock(&tasklist_lock).
165 * It must not be nested with write_lock_irq(&tasklist_lock),
166 * neither inside nor outside.
167 */
168static inline void task_lock(struct task_struct *p)
169{
170 spin_lock(&p->alloc_lock);
171}
172
173static inline void task_unlock(struct task_struct *p)
174{
175 spin_unlock(&p->alloc_lock);
176}
177
178#endif /* _LINUX_SCHED_TASK_H */