1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_UTSNAME_H
3#define _LINUX_UTSNAME_H
4
5
6#include <linux/sched.h>
7#include <linux/nsproxy.h>
8#include <linux/ns_common.h>
9#include <linux/err.h>
10#include <uapi/linux/utsname.h>
11
12enum uts_proc {
13	UTS_PROC_ARCH,
14	UTS_PROC_OSTYPE,
15	UTS_PROC_OSRELEASE,
16	UTS_PROC_VERSION,
17	UTS_PROC_HOSTNAME,
18	UTS_PROC_DOMAINNAME,
19};
20
21struct user_namespace;
22extern struct user_namespace init_user_ns;
23
24struct uts_namespace {
25	struct new_utsname name;
26	struct user_namespace *user_ns;
27	struct ucounts *ucounts;
28	struct ns_common ns;
29} __randomize_layout;
30extern struct uts_namespace init_uts_ns;
31
32#ifdef CONFIG_UTS_NS
33static inline void get_uts_ns(struct uts_namespace *ns)
34{
35	refcount_inc(&ns->ns.count);
36}
37
38extern struct uts_namespace *copy_utsname(unsigned long flags,
39	struct user_namespace *user_ns, struct uts_namespace *old_ns);
40extern void free_uts_ns(struct uts_namespace *ns);
41
42static inline void put_uts_ns(struct uts_namespace *ns)
43{
44	if (refcount_dec_and_test(&ns->ns.count))
45		free_uts_ns(ns);
46}
47
48void uts_ns_init(void);
49#else
50static inline void get_uts_ns(struct uts_namespace *ns)
51{
52}
53
54static inline void put_uts_ns(struct uts_namespace *ns)
55{
56}
57
58static inline struct uts_namespace *copy_utsname(unsigned long flags,
59	struct user_namespace *user_ns, struct uts_namespace *old_ns)
60{
61	if (flags & CLONE_NEWUTS)
62		return ERR_PTR(-EINVAL);
63
64	return old_ns;
65}
66
67static inline void uts_ns_init(void)
68{
69}
70#endif
71
72#ifdef CONFIG_PROC_SYSCTL
73extern void uts_proc_notify(enum uts_proc proc);
74#else
75static inline void uts_proc_notify(enum uts_proc proc)
76{
77}
78#endif
79
80static inline struct new_utsname *utsname(void)
81{
82	return &current->nsproxy->uts_ns->name;
83}
84
85static inline struct new_utsname *init_utsname(void)
86{
87	return &init_uts_ns.name;
88}
89
90extern struct rw_semaphore uts_sem;
91
92#endif /* _LINUX_UTSNAME_H */
93