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
50#ifdef CONFIG_PROVE_RCU
51extern int lockdep_tasklist_lock_is_held(void);
52#endif /* #ifdef CONFIG_PROVE_RCU */
53
54extern asmlinkage void schedule_tail(struct task_struct *prev);
55extern void init_idle(struct task_struct *idle, int cpu);
56
57extern int sched_fork(unsigned long clone_flags, 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
68#ifdef CONFIG_HAVE_COPY_THREAD_TLS
69extern int copy_thread_tls(unsigned long, unsigned long, unsigned long,
70 struct task_struct *, unsigned long);
71#else
72extern int copy_thread(unsigned long, unsigned long, unsigned long,
73 struct task_struct *);
74
75/* Architectures that haven't opted into copy_thread_tls get the tls argument
76 * via pt_regs, so ignore the tls argument passed via C. */
77static inline int copy_thread_tls(
78 unsigned long clone_flags, unsigned long sp, unsigned long arg,
79 struct task_struct *p, unsigned long tls)
80{
81 return copy_thread(clone_flags, sp, arg, p);
82}
83#endif
84extern void flush_thread(void);
85
86#ifdef CONFIG_HAVE_EXIT_THREAD
87extern void exit_thread(struct task_struct *tsk);
88#else
89static inline void exit_thread(struct task_struct *tsk)
90{
91}
92#endif
93extern void do_group_exit(int);
94
95extern void exit_files(struct task_struct *);
96extern void exit_itimers(struct signal_struct *);
97
98extern long _do_fork(struct kernel_clone_args *kargs);
99extern bool legacy_clone_args_valid(const struct kernel_clone_args *kargs);
100extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
101struct task_struct *fork_idle(int);
102struct mm_struct *copy_init_mm(void);
103extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
104extern long kernel_wait4(pid_t, int __user *, int, struct rusage *);
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
129void put_task_struct_rcu_user(struct task_struct *task);
130
131#ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
132extern int arch_task_struct_size __read_mostly;
133#else
134# define arch_task_struct_size (sizeof(struct task_struct))
135#endif
136
137#ifndef CONFIG_HAVE_ARCH_THREAD_STRUCT_WHITELIST
138/*
139 * If an architecture has not declared a thread_struct whitelist we
140 * must assume something there may need to be copied to userspace.
141 */
142static inline void arch_thread_struct_whitelist(unsigned long *offset,
143 unsigned long *size)
144{
145 *offset = 0;
146 /* Handle dynamically sized thread_struct. */
147 *size = arch_task_struct_size - offsetof(struct task_struct, thread);
148}
149#endif
150
151#ifdef CONFIG_VMAP_STACK
152static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
153{
154 return t->stack_vm_area;
155}
156#else
157static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
158{
159 return NULL;
160}
161#endif
162
163/*
164 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
165 * subscriptions and synchronises with wait4(). Also used in procfs. Also
166 * pins the final release of task.io_context. Also protects ->cpuset and
167 * ->cgroup.subsys[]. And ->vfork_done.
168 *
169 * Nests both inside and outside of read_lock(&tasklist_lock).
170 * It must not be nested with write_lock_irq(&tasklist_lock),
171 * neither inside nor outside.
172 */
173static inline void task_lock(struct task_struct *p)
174{
175 spin_lock(&p->alloc_lock);
176}
177
178static inline void task_unlock(struct task_struct *p)
179{
180 spin_unlock(&p->alloc_lock);
181}
182
183#endif /* _LINUX_SCHED_TASK_H */