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

source code of linux/include/linux/time_namespace.h