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
11 struct user_namespace;
12 extern struct user_namespace init_user_ns;
13
14 struct timens_offsets {
15 struct timespec64 monotonic;
16 struct timespec64 boottime;
17 };
18
19 struct 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
29 extern struct time_namespace init_time_ns;
30
31 #ifdef CONFIG_TIME_NS
32 extern int vdso_join_timens(struct task_struct *task,
33 struct time_namespace *ns);
34 extern void timens_commit(struct task_struct *tsk, struct time_namespace *ns);
35
get_time_ns(struct time_namespace * ns)36 static inline struct time_namespace *get_time_ns(struct time_namespace *ns)
37 {
38 refcount_inc(&ns->ns.count);
39 return ns;
40 }
41
42 struct time_namespace *copy_time_ns(unsigned long flags,
43 struct user_namespace *user_ns,
44 struct time_namespace *old_ns);
45 void free_time_ns(struct time_namespace *ns);
46 void timens_on_fork(struct nsproxy *nsproxy, struct task_struct *tsk);
47 struct vdso_data *arch_get_vdso_data(void *vvar_page);
48 struct page *find_timens_vvar_page(struct vm_area_struct *vma);
49
put_time_ns(struct time_namespace * ns)50 static inline void put_time_ns(struct time_namespace *ns)
51 {
52 if (refcount_dec_and_test(&ns->ns.count))
53 free_time_ns(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
timens_add_boottime_ns(u64 nsec)80 static inline u64 timens_add_boottime_ns(u64 nsec)
81 {
82 struct timens_offsets *ns_offsets = ¤t->nsproxy->time_ns->offsets;
83
84 return nsec + timespec64_to_ns(&ns_offsets->boottime);
85 }
86
timens_sub_boottime(struct timespec64 * ts)87 static inline void timens_sub_boottime(struct timespec64 *ts)
88 {
89 struct timens_offsets *ns_offsets = ¤t->nsproxy->time_ns->offsets;
90
91 *ts = timespec64_sub(*ts, ns_offsets->boottime);
92 }
93
94 ktime_t do_timens_ktime_to_host(clockid_t clockid, ktime_t tim,
95 struct timens_offsets *offsets);
96
timens_ktime_to_host(clockid_t clockid,ktime_t tim)97 static inline ktime_t timens_ktime_to_host(clockid_t clockid, ktime_t tim)
98 {
99 struct time_namespace *ns = current->nsproxy->time_ns;
100
101 if (likely(ns == &init_time_ns))
102 return tim;
103
104 return do_timens_ktime_to_host(clockid, tim, &ns->offsets);
105 }
106
107 #else
vdso_join_timens(struct task_struct * task,struct time_namespace * ns)108 static inline int vdso_join_timens(struct task_struct *task,
109 struct time_namespace *ns)
110 {
111 return 0;
112 }
113
timens_commit(struct task_struct * tsk,struct time_namespace * ns)114 static inline void timens_commit(struct task_struct *tsk,
115 struct time_namespace *ns)
116 {
117 }
118
get_time_ns(struct time_namespace * ns)119 static inline struct time_namespace *get_time_ns(struct time_namespace *ns)
120 {
121 return NULL;
122 }
123
put_time_ns(struct time_namespace * ns)124 static inline void put_time_ns(struct time_namespace *ns)
125 {
126 }
127
128 static inline
copy_time_ns(unsigned long flags,struct user_namespace * user_ns,struct time_namespace * old_ns)129 struct time_namespace *copy_time_ns(unsigned long flags,
130 struct user_namespace *user_ns,
131 struct time_namespace *old_ns)
132 {
133 if (flags & CLONE_NEWTIME)
134 return ERR_PTR(-EINVAL);
135
136 return old_ns;
137 }
138
timens_on_fork(struct nsproxy * nsproxy,struct task_struct * tsk)139 static inline void timens_on_fork(struct nsproxy *nsproxy,
140 struct task_struct *tsk)
141 {
142 return;
143 }
144
find_timens_vvar_page(struct vm_area_struct * vma)145 static inline struct page *find_timens_vvar_page(struct vm_area_struct *vma)
146 {
147 return NULL;
148 }
149
timens_add_monotonic(struct timespec64 * ts)150 static inline void timens_add_monotonic(struct timespec64 *ts) { }
timens_add_boottime(struct timespec64 * ts)151 static inline void timens_add_boottime(struct timespec64 *ts) { }
152
timens_add_boottime_ns(u64 nsec)153 static inline u64 timens_add_boottime_ns(u64 nsec)
154 {
155 return nsec;
156 }
157
timens_sub_boottime(struct timespec64 * ts)158 static inline void timens_sub_boottime(struct timespec64 *ts) { }
159
timens_ktime_to_host(clockid_t clockid,ktime_t tim)160 static inline ktime_t timens_ktime_to_host(clockid_t clockid, ktime_t tim)
161 {
162 return tim;
163 }
164 #endif
165
166 #endif /* _LINUX_TIMENS_H */
167