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/kref.h>
8 #include <linux/nsproxy.h>
9 #include <linux/ns_common.h>
10 #include <linux/err.h>
11
12 struct user_namespace;
13 extern struct user_namespace init_user_ns;
14
15 struct timens_offsets {
16 struct timespec64 monotonic;
17 struct timespec64 boottime;
18 };
19
20 struct time_namespace {
21 struct kref kref;
22 struct user_namespace *user_ns;
23 struct ucounts *ucounts;
24 struct ns_common ns;
25 struct timens_offsets offsets;
26 struct page *vvar_page;
27 /* If set prevents changing offsets after any task joined namespace. */
28 bool frozen_offsets;
29 } __randomize_layout;
30
31 extern struct time_namespace init_time_ns;
32
33 #ifdef CONFIG_TIME_NS
34 extern int vdso_join_timens(struct task_struct *task,
35 struct time_namespace *ns);
36 extern void timens_commit(struct task_struct *tsk, struct time_namespace *ns);
37
get_time_ns(struct time_namespace * ns)38 static inline struct time_namespace *get_time_ns(struct time_namespace *ns)
39 {
40 kref_get(&ns->kref);
41 return ns;
42 }
43
44 struct time_namespace *copy_time_ns(unsigned long flags,
45 struct user_namespace *user_ns,
46 struct time_namespace *old_ns);
47 void free_time_ns(struct kref *kref);
48 int timens_on_fork(struct nsproxy *nsproxy, struct task_struct *tsk);
49 struct vdso_data *arch_get_vdso_data(void *vvar_page);
50
put_time_ns(struct time_namespace * ns)51 static inline void put_time_ns(struct time_namespace *ns)
52 {
53 kref_put(&ns->kref, free_time_ns);
54 }
55
56 void proc_timens_show_offsets(struct task_struct *p, struct seq_file *m);
57
58 struct proc_timens_offset {
59 int clockid;
60 struct timespec64 val;
61 };
62
63 int proc_timens_set_offset(struct file *file, struct task_struct *p,
64 struct proc_timens_offset *offsets, int n);
65
timens_add_monotonic(struct timespec64 * ts)66 static inline void timens_add_monotonic(struct timespec64 *ts)
67 {
68 struct timens_offsets *ns_offsets = ¤t->nsproxy->time_ns->offsets;
69
70 *ts = timespec64_add(*ts, ns_offsets->monotonic);
71 }
72
timens_add_boottime(struct timespec64 * ts)73 static inline void timens_add_boottime(struct timespec64 *ts)
74 {
75 struct timens_offsets *ns_offsets = ¤t->nsproxy->time_ns->offsets;
76
77 *ts = timespec64_add(*ts, ns_offsets->boottime);
78 }
79
80 ktime_t do_timens_ktime_to_host(clockid_t clockid, ktime_t tim,
81 struct timens_offsets *offsets);
82
timens_ktime_to_host(clockid_t clockid,ktime_t tim)83 static inline ktime_t timens_ktime_to_host(clockid_t clockid, ktime_t tim)
84 {
85 struct time_namespace *ns = current->nsproxy->time_ns;
86
87 if (likely(ns == &init_time_ns))
88 return tim;
89
90 return do_timens_ktime_to_host(clockid, tim, &ns->offsets);
91 }
92
93 #else
vdso_join_timens(struct task_struct * task,struct time_namespace * ns)94 static inline int vdso_join_timens(struct task_struct *task,
95 struct time_namespace *ns)
96 {
97 return 0;
98 }
99
timens_commit(struct task_struct * tsk,struct time_namespace * ns)100 static inline void timens_commit(struct task_struct *tsk,
101 struct time_namespace *ns)
102 {
103 }
104
get_time_ns(struct time_namespace * ns)105 static inline struct time_namespace *get_time_ns(struct time_namespace *ns)
106 {
107 return NULL;
108 }
109
put_time_ns(struct time_namespace * ns)110 static inline void put_time_ns(struct time_namespace *ns)
111 {
112 }
113
114 static inline
copy_time_ns(unsigned long flags,struct user_namespace * user_ns,struct time_namespace * old_ns)115 struct time_namespace *copy_time_ns(unsigned long flags,
116 struct user_namespace *user_ns,
117 struct time_namespace *old_ns)
118 {
119 if (flags & CLONE_NEWTIME)
120 return ERR_PTR(-EINVAL);
121
122 return old_ns;
123 }
124
timens_on_fork(struct nsproxy * nsproxy,struct task_struct * tsk)125 static inline int timens_on_fork(struct nsproxy *nsproxy,
126 struct task_struct *tsk)
127 {
128 return 0;
129 }
130
timens_add_monotonic(struct timespec64 * ts)131 static inline void timens_add_monotonic(struct timespec64 *ts) { }
timens_add_boottime(struct timespec64 * ts)132 static inline void timens_add_boottime(struct timespec64 *ts) { }
timens_ktime_to_host(clockid_t clockid,ktime_t tim)133 static inline ktime_t timens_ktime_to_host(clockid_t clockid, ktime_t tim)
134 {
135 return tim;
136 }
137 #endif
138
139 #endif /* _LINUX_TIMENS_H */
140