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