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;
16
17/* All the bits taken by the old clone syscall. */
18#define CLONE_LEGACY_FLAGS 0xffffffffULL
19
20struct kernel_clone_args {
21 u64 flags;
22 int __user *pidfd;
23 int __user *child_tid;
24 int __user *parent_tid;
25 int exit_signal;
26 unsigned long stack;
27 unsigned long stack_size;
28 unsigned long tls;
29 pid_t *set_tid;
30 /* Number of elements in *set_tid */
31 size_t set_tid_size;
32};
33
34/*
35 * This serializes "schedule()" and also protects
36 * the run-queue from deletions/modifications (but
37 * _adding_ to the beginning of the run-queue has
38 * a separate lock).
39 */
40extern rwlock_t tasklist_lock;
41extern spinlock_t mmlist_lock;
42
43extern union thread_union init_thread_union;
44extern struct task_struct init_task;
45
46#ifdef CONFIG_PROVE_RCU
47extern int lockdep_tasklist_lock_is_held(void);
48#endif /* #ifdef CONFIG_PROVE_RCU */
49
50extern asmlinkage void schedule_tail(struct task_struct *prev);
51extern void init_idle(struct task_struct *idle, int cpu);
52
53extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
54extern void sched_dead(struct task_struct *p);
55
56void __noreturn do_task_dead(void);
57
58extern void proc_caches_init(void);
59
60extern void fork_init(void);
61
62extern void release_task(struct task_struct * p);
63
64#ifdef CONFIG_HAVE_COPY_THREAD_TLS
65extern int copy_thread_tls(unsigned long, unsigned long, unsigned long,
66 struct task_struct *, unsigned long);
67#else
68extern int copy_thread(unsigned long, unsigned long, unsigned long,
69 struct task_struct *);
70
71/* Architectures that haven't opted into copy_thread_tls get the tls argument
72 * via pt_regs, so ignore the tls argument passed via C. */
73static inline int copy_thread_tls(
74 unsigned long clone_flags, unsigned long sp, unsigned long arg,
75 struct task_struct *p, unsigned long tls)
76{
77 return copy_thread(clone_flags, sp, arg, p);
78}
79#endif
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 void do_group_exit(int);
90
91extern void exit_files(struct task_struct *);
92extern void exit_itimers(struct signal_struct *);
93
94extern long _do_fork(struct kernel_clone_args *kargs);
95extern bool legacy_clone_args_valid(const struct kernel_clone_args *kargs);
96extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
97struct task_struct *fork_idle(int);
98struct mm_struct *copy_init_mm(void);
99extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
100extern long kernel_wait4(pid_t, int __user *, int, struct rusage *);
101
102extern void free_task(struct task_struct *tsk);
103
104/* sched_exec is called by processes performing an exec */
105#ifdef CONFIG_SMP
106extern void sched_exec(void);
107#else
108#define sched_exec() {}
109#endif
110
111static inline struct task_struct *get_task_struct(struct task_struct *t)
112{
113 refcount_inc(&t->usage);
114 return t;
115}
116
117extern void __put_task_struct(struct task_struct *t);
118
119static inline void put_task_struct(struct task_struct *t)
120{
121 if (refcount_dec_and_test(&t->usage))
122 __put_task_struct(t);
123}
124
125void put_task_struct_rcu_user(struct task_struct *task);
126
127#ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
128extern int arch_task_struct_size __read_mostly;
129#else
130# define arch_task_struct_size (sizeof(struct task_struct))
131#endif
132
133#ifndef CONFIG_HAVE_ARCH_THREAD_STRUCT_WHITELIST
134/*
135 * If an architecture has not declared a thread_struct whitelist we
136 * must assume something there may need to be copied to userspace.
137 */
138static inline void arch_thread_struct_whitelist(unsigned long *offset,
139 unsigned long *size)
140{
141 *offset = 0;
142 /* Handle dynamically sized thread_struct. */
143 *size = arch_task_struct_size - offsetof(struct task_struct, thread);
144}
145#endif
146
147#ifdef CONFIG_VMAP_STACK
148static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
149{
150 return t->stack_vm_area;
151}
152#else
153static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
154{
155 return NULL;
156}
157#endif
158
159/*
160 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
161 * subscriptions and synchronises with wait4(). Also used in procfs. Also
162 * pins the final release of task.io_context. Also protects ->cpuset and
163 * ->cgroup.subsys[]. And ->vfork_done.
164 *
165 * Nests both inside and outside of read_lock(&tasklist_lock).
166 * It must not be nested with write_lock_irq(&tasklist_lock),
167 * neither inside nor outside.
168 */
169static inline void task_lock(struct task_struct *p)
170{
171 spin_lock(&p->alloc_lock);
172}
173
174static inline void task_unlock(struct task_struct *p)
175{
176 spin_unlock(&p->alloc_lock);
177}
178
179#endif /* _LINUX_SCHED_TASK_H */