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

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