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};
30
31/*
32 * This serializes "schedule()" and also protects
33 * the run-queue from deletions/modifications (but
34 * _adding_ to the beginning of the run-queue has
35 * a separate lock).
36 */
37extern rwlock_t tasklist_lock;
38extern spinlock_t mmlist_lock;
39
40extern union thread_union init_thread_union;
41extern struct task_struct init_task;
42
43#ifdef CONFIG_PROVE_RCU
44extern int lockdep_tasklist_lock_is_held(void);
45#endif /* #ifdef CONFIG_PROVE_RCU */
46
47extern asmlinkage void schedule_tail(struct task_struct *prev);
48extern void init_idle(struct task_struct *idle, int cpu);
49
50extern int sched_fork(unsigned long clone_flags, struct task_struct *p);
51extern void sched_dead(struct task_struct *p);
52
53void __noreturn do_task_dead(void);
54
55extern void proc_caches_init(void);
56
57extern void fork_init(void);
58
59extern void release_task(struct task_struct * p);
60
61#ifdef CONFIG_HAVE_COPY_THREAD_TLS
62extern int copy_thread_tls(unsigned long, unsigned long, unsigned long,
63 struct task_struct *, unsigned long);
64#else
65extern int copy_thread(unsigned long, unsigned long, unsigned long,
66 struct task_struct *);
67
68/* Architectures that haven't opted into copy_thread_tls get the tls argument
69 * via pt_regs, so ignore the tls argument passed via C. */
70static inline int copy_thread_tls(
71 unsigned long clone_flags, unsigned long sp, unsigned long arg,
72 struct task_struct *p, unsigned long tls)
73{
74 return copy_thread(clone_flags, sp, arg, p);
75}
76#endif
77extern void flush_thread(void);
78
79#ifdef CONFIG_HAVE_EXIT_THREAD
80extern void exit_thread(struct task_struct *tsk);
81#else
82static inline void exit_thread(struct task_struct *tsk)
83{
84}
85#endif
86extern void do_group_exit(int);
87
88extern void exit_files(struct task_struct *);
89extern void exit_itimers(struct signal_struct *);
90
91extern long _do_fork(struct kernel_clone_args *kargs);
92extern bool legacy_clone_args_valid(const struct kernel_clone_args *kargs);
93extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
94struct task_struct *fork_idle(int);
95struct mm_struct *copy_init_mm(void);
96extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
97extern long kernel_wait4(pid_t, int __user *, int, struct rusage *);
98
99extern void free_task(struct task_struct *tsk);
100
101/* sched_exec is called by processes performing an exec */
102#ifdef CONFIG_SMP
103extern void sched_exec(void);
104#else
105#define sched_exec() {}
106#endif
107
108#define get_task_struct(tsk) do { refcount_inc(&(tsk)->usage); } while(0)
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
118struct task_struct *task_rcu_dereference(struct task_struct **ptask);
119
120#ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
121extern int arch_task_struct_size __read_mostly;
122#else
123# define arch_task_struct_size (sizeof(struct task_struct))
124#endif
125
126#ifndef CONFIG_HAVE_ARCH_THREAD_STRUCT_WHITELIST
127/*
128 * If an architecture has not declared a thread_struct whitelist we
129 * must assume something there may need to be copied to userspace.
130 */
131static inline void arch_thread_struct_whitelist(unsigned long *offset,
132 unsigned long *size)
133{
134 *offset = 0;
135 /* Handle dynamically sized thread_struct. */
136 *size = arch_task_struct_size - offsetof(struct task_struct, thread);
137}
138#endif
139
140#ifdef CONFIG_VMAP_STACK
141static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
142{
143 return t->stack_vm_area;
144}
145#else
146static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
147{
148 return NULL;
149}
150#endif
151
152/*
153 * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
154 * subscriptions and synchronises with wait4(). Also used in procfs. Also
155 * pins the final release of task.io_context. Also protects ->cpuset and
156 * ->cgroup.subsys[]. And ->vfork_done.
157 *
158 * Nests both inside and outside of read_lock(&tasklist_lock).
159 * It must not be nested with write_lock_irq(&tasklist_lock),
160 * neither inside nor outside.
161 */
162static inline void task_lock(struct task_struct *p)
163{
164 spin_lock(&p->alloc_lock);
165}
166
167static inline void task_unlock(struct task_struct *p)
168{
169 spin_unlock(&p->alloc_lock);
170}
171
172#endif /* _LINUX_SCHED_TASK_H */