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 page *find_timens_vvar_page(struct vm_area_struct *vma);
48
put_time_ns(struct time_namespace * ns)49 static inline void put_time_ns(struct time_namespace *ns)
50 {
51 if (refcount_dec_and_test(&ns->ns.count))
52 free_time_ns(ns);
53 }
54
55 void proc_timens_show_offsets(struct task_struct *p, struct seq_file *m);
56
57 struct proc_timens_offset {
58 int clockid;
59 struct timespec64 val;
60 };
61
62 int proc_timens_set_offset(struct file *file, struct task_struct *p,
63 struct proc_timens_offset *offsets, int n);
64
timens_add_monotonic(struct timespec64 * ts)65 static inline void timens_add_monotonic(struct timespec64 *ts)
66 {
67 struct timens_offsets *ns_offsets = ¤t->nsproxy->time_ns->offsets;
68
69 *ts = timespec64_add(*ts, ns_offsets->monotonic);
70 }
71
timens_add_boottime(struct timespec64 * ts)72 static inline void timens_add_boottime(struct timespec64 *ts)
73 {
74 struct timens_offsets *ns_offsets = ¤t->nsproxy->time_ns->offsets;
75
76 *ts = timespec64_add(*ts, ns_offsets->boottime);
77 }
78
timens_add_boottime_ns(u64 nsec)79 static inline u64 timens_add_boottime_ns(u64 nsec)
80 {
81 struct timens_offsets *ns_offsets = ¤t->nsproxy->time_ns->offsets;
82
83 return nsec + timespec64_to_ns(&ns_offsets->boottime);
84 }
85
timens_sub_boottime(struct timespec64 * ts)86 static inline void timens_sub_boottime(struct timespec64 *ts)
87 {
88 struct timens_offsets *ns_offsets = ¤t->nsproxy->time_ns->offsets;
89
90 *ts = timespec64_sub(*ts, ns_offsets->boottime);
91 }
92
93 ktime_t do_timens_ktime_to_host(clockid_t clockid, ktime_t tim,
94 struct timens_offsets *offsets);
95
timens_ktime_to_host(clockid_t clockid,ktime_t tim)96 static 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, &ns->offsets);
104 }
105
106 #else
vdso_join_timens(struct task_struct * task,struct time_namespace * ns)107 static inline int vdso_join_timens(struct task_struct *task,
108 struct time_namespace *ns)
109 {
110 return 0;
111 }
112
timens_commit(struct task_struct * tsk,struct time_namespace * ns)113 static inline void timens_commit(struct task_struct *tsk,
114 struct time_namespace *ns)
115 {
116 }
117
get_time_ns(struct time_namespace * ns)118 static inline struct time_namespace *get_time_ns(struct time_namespace *ns)
119 {
120 return NULL;
121 }
122
put_time_ns(struct time_namespace * ns)123 static inline void put_time_ns(struct time_namespace *ns)
124 {
125 }
126
127 static inline
copy_time_ns(unsigned long flags,struct user_namespace * user_ns,struct time_namespace * old_ns)128 struct 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
timens_on_fork(struct nsproxy * nsproxy,struct task_struct * tsk)138 static inline void timens_on_fork(struct nsproxy *nsproxy,
139 struct task_struct *tsk)
140 {
141 return;
142 }
143
find_timens_vvar_page(struct vm_area_struct * vma)144 static inline struct page *find_timens_vvar_page(struct vm_area_struct *vma)
145 {
146 return NULL;
147 }
148
timens_add_monotonic(struct timespec64 * ts)149 static inline void timens_add_monotonic(struct timespec64 *ts) { }
timens_add_boottime(struct timespec64 * ts)150 static inline void timens_add_boottime(struct timespec64 *ts) { }
151
timens_add_boottime_ns(u64 nsec)152 static inline u64 timens_add_boottime_ns(u64 nsec)
153 {
154 return nsec;
155 }
156
timens_sub_boottime(struct timespec64 * ts)157 static inline void timens_sub_boottime(struct timespec64 *ts) { }
158
timens_ktime_to_host(clockid_t clockid,ktime_t tim)159 static inline ktime_t timens_ktime_to_host(clockid_t clockid, ktime_t tim)
160 {
161 return tim;
162 }
163 #endif
164
165 struct vdso_data *arch_get_vdso_data(void *vvar_page);
166
167 #endif /* _LINUX_TIMENS_H */
168