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 const char *name;
27 int exit_signal;
28 u32 kthread:1;
29 u32 io_thread:1;
30 u32 user_worker:1;
31 u32 no_files:1;
32 unsigned long stack;
33 unsigned long stack_size;
34 unsigned long tls;
35 pid_t *set_tid;
36 /* Number of elements in *set_tid */
37 size_t set_tid_size;
38 int cgroup;
39 int idle;
40 int (*fn)(void *);
41 void *fn_arg;
42 struct cgroup *cgrp;
43 struct css_set *cset;
44};
45
46/*
47 * This serializes "schedule()" and also protects
48 * the run-queue from deletions/modifications (but
49 * _adding_ to the beginning of the run-queue has
50 * a separate lock).
51 */
52extern rwlock_t tasklist_lock;
53extern spinlock_t mmlist_lock;
54
55extern union thread_union init_thread_union;
56extern struct task_struct init_task;
57
58extern int lockdep_tasklist_lock_is_held(void);
59
60extern asmlinkage void schedule_tail(struct task_struct *prev);
61extern void init_idle(struct task_struct *idle, int cpu);
62
63extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
64extern void sched_cgroup_fork(struct task_struct *p, struct kernel_clone_args *kargs);
65extern void sched_post_fork(struct task_struct *p);
66extern void sched_dead(struct task_struct *p);
67
68void __noreturn do_task_dead(void);
69void __noreturn make_task_dead(int signr);
70
71extern void mm_cache_init(void);
72extern void proc_caches_init(void);
73
74extern void fork_init(void);
75
76extern void release_task(struct task_struct * p);
77
78extern int copy_thread(struct task_struct *, const struct kernel_clone_args *);
79
80extern void flush_thread(void);
81
82#ifdef CONFIG_HAVE_EXIT_THREAD
83extern void exit_thread(struct task_struct *tsk);
84#else
85static inline void exit_thread(struct task_struct *tsk)
86{
87}
88#endif
89extern __noreturn void do_group_exit(int);
90
91extern void exit_files(struct task_struct *);
92extern void exit_itimers(struct task_struct *);
93
94extern pid_t kernel_clone(struct kernel_clone_args *kargs);
95struct task_struct *copy_process(struct pid *pid, int trace, int node,
96 struct kernel_clone_args *args);
97struct task_struct *create_io_thread(int (*fn)(void *), void *arg, int node);
98struct task_struct *fork_idle(int);
99extern pid_t kernel_thread(int (*fn)(void *), void *arg, const char *name,
100 unsigned long flags);
101extern pid_t user_mode_thread(int (*fn)(void *), void *arg, unsigned long flags);
102extern long kernel_wait4(pid_t, int __user *, int, struct rusage *);
103int kernel_wait(pid_t pid, int *stat);
104
105extern void free_task(struct task_struct *tsk);
106
107/* sched_exec is called by processes performing an exec */
108#ifdef CONFIG_SMP
109extern void sched_exec(void);
110#else
111#define sched_exec() {}
112#endif
113
114static inline struct task_struct *get_task_struct(struct task_struct *t)
115{
116 refcount_inc(&t->usage);
117 return t;
118}
119
120extern void __put_task_struct(struct task_struct *t);
121
122static inline void put_task_struct(struct task_struct *t)
123{
124 if (refcount_dec_and_test(&t->usage))
125 __put_task_struct(t);
126}
127
128static inline void put_task_struct_many(struct task_struct *t, int nr)
129{
130 if (refcount_sub_and_test(nr, &t->usage))
131 __put_task_struct(t);
132}
133
134void put_task_struct_rcu_user(struct task_struct *task);
135
136/* Free all architecture-specific resources held by a thread. */
137void release_thread(struct task_struct *dead_task);
138
139#ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
140extern int arch_task_struct_size __read_mostly;
141#else
142# define arch_task_struct_size (sizeof(struct task_struct))
143#endif
144
145#ifndef CONFIG_HAVE_ARCH_THREAD_STRUCT_WHITELIST
146/*
147 * If an architecture has not declared a thread_struct whitelist we
148 * must assume something there may need to be copied to userspace.
149 */
150static inline void arch_thread_struct_whitelist(unsigned long *offset,
151 unsigned long *size)
152{
153 *offset = 0;
154 /* Handle dynamically sized thread_struct. */
155 *size = arch_task_struct_size - offsetof(struct task_struct, thread);
156}
157#endif
158
159#ifdef CONFIG_VMAP_STACK
160static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
161{
162 return t->stack_vm_area;
163}
164#else
165static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
166{
167 return NULL;
168}
169#endif
170
171/*
172 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
173 * subscriptions and synchronises with wait4(). Also used in procfs. Also
174 * pins the final release of task.io_context. Also protects ->cpuset and
175 * ->cgroup.subsys[]. And ->vfork_done. And ->sysvshm.shm_clist.
176 *
177 * Nests both inside and outside of read_lock(&tasklist_lock).
178 * It must not be nested with write_lock_irq(&tasklist_lock),
179 * neither inside nor outside.
180 */
181static inline void task_lock(struct task_struct *p)
182{
183 spin_lock(&p->alloc_lock);
184}
185
186static inline void task_unlock(struct task_struct *p)
187{
188 spin_unlock(&p->alloc_lock);
189}
190
191#endif /* _LINUX_SCHED_TASK_H */