1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_TIMENS_H
3#define _LINUX_TIMENS_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 <linux/time64.h>
11
12struct user_namespace;
13extern struct user_namespace init_user_ns;
14
15struct seq_file;
16struct vm_area_struct;
17
18struct timens_offsets {
19 struct timespec64 monotonic;
20 struct timespec64 boottime;
21};
22
23struct time_namespace {
24 struct user_namespace *user_ns;
25 struct ucounts *ucounts;
26 struct ns_common ns;
27 struct timens_offsets offsets;
28 struct page *vvar_page;
29 /* If set prevents changing offsets after any task joined namespace. */
30 bool frozen_offsets;
31} __randomize_layout;
32
33extern struct time_namespace init_time_ns;
34
35#ifdef CONFIG_TIME_NS
36static inline struct time_namespace *to_time_ns(struct ns_common *ns)
37{
38 return container_of(ns, struct time_namespace, ns);
39}
40void __init time_ns_init(void);
41extern int vdso_join_timens(struct task_struct *task,
42 struct time_namespace *ns);
43extern void timens_commit(struct task_struct *tsk, struct time_namespace *ns);
44
45static inline struct time_namespace *get_time_ns(struct time_namespace *ns)
46{
47 ns_ref_inc(ns);
48 return ns;
49}
50
51struct time_namespace *copy_time_ns(u64 flags,
52 struct user_namespace *user_ns,
53 struct time_namespace *old_ns);
54void free_time_ns(struct time_namespace *ns);
55void timens_on_fork(struct nsproxy *nsproxy, struct task_struct *tsk);
56struct page *find_timens_vvar_page(struct vm_area_struct *vma);
57
58static inline void put_time_ns(struct time_namespace *ns)
59{
60 if (ns_ref_put(ns))
61 free_time_ns(ns);
62}
63
64void proc_timens_show_offsets(struct task_struct *p, struct seq_file *m);
65
66struct proc_timens_offset {
67 int clockid;
68 struct timespec64 val;
69};
70
71int proc_timens_set_offset(struct file *file, struct task_struct *p,
72 struct proc_timens_offset *offsets, int n);
73
74static inline void timens_add_monotonic(struct timespec64 *ts)
75{
76 struct timens_offsets *ns_offsets = &current->nsproxy->time_ns->offsets;
77
78 *ts = timespec64_add(lhs: *ts, rhs: ns_offsets->monotonic);
79}
80
81static inline void timens_add_boottime(struct timespec64 *ts)
82{
83 struct timens_offsets *ns_offsets = &current->nsproxy->time_ns->offsets;
84
85 *ts = timespec64_add(lhs: *ts, rhs: ns_offsets->boottime);
86}
87
88static inline u64 timens_add_boottime_ns(u64 nsec)
89{
90 struct timens_offsets *ns_offsets = &current->nsproxy->time_ns->offsets;
91
92 return nsec + timespec64_to_ns(ts: &ns_offsets->boottime);
93}
94
95static inline void timens_sub_boottime(struct timespec64 *ts)
96{
97 struct timens_offsets *ns_offsets = &current->nsproxy->time_ns->offsets;
98
99 *ts = timespec64_sub(lhs: *ts, rhs: ns_offsets->boottime);
100}
101
102ktime_t do_timens_ktime_to_host(clockid_t clockid, ktime_t tim,
103 struct timens_offsets *offsets);
104
105static inline ktime_t timens_ktime_to_host(clockid_t clockid, ktime_t tim)
106{
107 struct time_namespace *ns = current->nsproxy->time_ns;
108
109 if (likely(ns == &init_time_ns))
110 return tim;
111
112 return do_timens_ktime_to_host(clockid, tim, offsets: &ns->offsets);
113}
114
115#else
116static inline void __init time_ns_init(void)
117{
118}
119
120static inline int vdso_join_timens(struct task_struct *task,
121 struct time_namespace *ns)
122{
123 return 0;
124}
125
126static inline void timens_commit(struct task_struct *tsk,
127 struct time_namespace *ns)
128{
129}
130
131static inline struct time_namespace *get_time_ns(struct time_namespace *ns)
132{
133 return NULL;
134}
135
136static inline void put_time_ns(struct time_namespace *ns)
137{
138}
139
140static inline
141struct time_namespace *copy_time_ns(u64 flags,
142 struct user_namespace *user_ns,
143 struct time_namespace *old_ns)
144{
145 if (flags & CLONE_NEWTIME)
146 return ERR_PTR(-EINVAL);
147
148 return old_ns;
149}
150
151static inline void timens_on_fork(struct nsproxy *nsproxy,
152 struct task_struct *tsk)
153{
154 return;
155}
156
157static inline struct page *find_timens_vvar_page(struct vm_area_struct *vma)
158{
159 return NULL;
160}
161
162static inline void timens_add_monotonic(struct timespec64 *ts) { }
163static inline void timens_add_boottime(struct timespec64 *ts) { }
164
165static inline u64 timens_add_boottime_ns(u64 nsec)
166{
167 return nsec;
168}
169
170static inline void timens_sub_boottime(struct timespec64 *ts) { }
171
172static inline ktime_t timens_ktime_to_host(clockid_t clockid, ktime_t tim)
173{
174 return tim;
175}
176#endif
177
178#endif /* _LINUX_TIMENS_H */
179