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 #include <vdso/datapage.h> 12 13 struct user_namespace; 14 extern struct user_namespace init_user_ns; 15 16 struct vm_area_struct; 17 18 struct timens_offsets { 19 struct timespec64 monotonic; 20 struct timespec64 boottime; 21 }; 22 23 struct time_namespace { 24 struct user_namespace *user_ns; 25 struct ucounts *ucounts; 26 struct ns_common ns; 27 struct timens_offsets offsets; 28 struct page *vvar_page; 29 /* If set prevents changing offsets after any task joined namespace. */ 30 bool frozen_offsets; 31 } __randomize_layout; 32 33 extern struct time_namespace init_time_ns; 34 35 #ifdef CONFIG_TIME_NS 36 extern int vdso_join_timens(struct task_struct *task, 37 struct time_namespace *ns); 38 extern void timens_commit(struct task_struct *tsk, struct time_namespace *ns); 39 40 static inline struct time_namespace *get_time_ns(struct time_namespace *ns) 41 { 42 refcount_inc(&ns->ns.count); 43 return ns; 44 } 45 46 struct time_namespace *copy_time_ns(unsigned long flags, 47 struct user_namespace *user_ns, 48 struct time_namespace *old_ns); 49 void free_time_ns(struct time_namespace *ns); 50 void timens_on_fork(struct nsproxy *nsproxy, struct task_struct *tsk); 51 struct page *find_timens_vvar_page(struct vm_area_struct *vma); 52 53 static inline void put_time_ns(struct time_namespace *ns) 54 { 55 if (refcount_dec_and_test(&ns->ns.count)) 56 free_time_ns(ns); 57 } 58 59 void proc_timens_show_offsets(struct task_struct *p, struct seq_file *m); 60 61 struct proc_timens_offset { 62 int clockid; 63 struct timespec64 val; 64 }; 65 66 int proc_timens_set_offset(struct file *file, struct task_struct *p, 67 struct proc_timens_offset *offsets, int n); 68 69 static inline void timens_add_monotonic(struct timespec64 *ts) 70 { 71 struct timens_offsets *ns_offsets = ¤t->nsproxy->time_ns->offsets; 72 73 *ts = timespec64_add(*ts, ns_offsets->monotonic); 74 } 75 76 static inline void timens_add_boottime(struct timespec64 *ts) 77 { 78 struct timens_offsets *ns_offsets = ¤t->nsproxy->time_ns->offsets; 79 80 *ts = timespec64_add(*ts, ns_offsets->boottime); 81 } 82 83 static inline u64 timens_add_boottime_ns(u64 nsec) 84 { 85 struct timens_offsets *ns_offsets = ¤t->nsproxy->time_ns->offsets; 86 87 return nsec + timespec64_to_ns(&ns_offsets->boottime); 88 } 89 90 static inline void timens_sub_boottime(struct timespec64 *ts) 91 { 92 struct timens_offsets *ns_offsets = ¤t->nsproxy->time_ns->offsets; 93 94 *ts = timespec64_sub(*ts, ns_offsets->boottime); 95 } 96 97 ktime_t do_timens_ktime_to_host(clockid_t clockid, ktime_t tim, 98 struct timens_offsets *offsets); 99 100 static inline ktime_t timens_ktime_to_host(clockid_t clockid, ktime_t tim) 101 { 102 struct time_namespace *ns = current->nsproxy->time_ns; 103 104 if (likely(ns == &init_time_ns)) 105 return tim; 106 107 return do_timens_ktime_to_host(clockid, tim, &ns->offsets); 108 } 109 110 #else 111 static inline int vdso_join_timens(struct task_struct *task, 112 struct time_namespace *ns) 113 { 114 return 0; 115 } 116 117 static inline void timens_commit(struct task_struct *tsk, 118 struct time_namespace *ns) 119 { 120 } 121 122 static inline struct time_namespace *get_time_ns(struct time_namespace *ns) 123 { 124 return NULL; 125 } 126 127 static inline void put_time_ns(struct time_namespace *ns) 128 { 129 } 130 131 static inline 132 struct time_namespace *copy_time_ns(unsigned long flags, 133 struct user_namespace *user_ns, 134 struct time_namespace *old_ns) 135 { 136 if (flags & CLONE_NEWTIME) 137 return ERR_PTR(-EINVAL); 138 139 return old_ns; 140 } 141 142 static inline void timens_on_fork(struct nsproxy *nsproxy, 143 struct task_struct *tsk) 144 { 145 return; 146 } 147 148 static inline struct page *find_timens_vvar_page(struct vm_area_struct *vma) 149 { 150 return NULL; 151 } 152 153 static inline void timens_add_monotonic(struct timespec64 *ts) { } 154 static inline void timens_add_boottime(struct timespec64 *ts) { } 155 156 static inline u64 timens_add_boottime_ns(u64 nsec) 157 { 158 return nsec; 159 } 160 161 static inline void timens_sub_boottime(struct timespec64 *ts) { } 162 163 static inline ktime_t timens_ktime_to_host(clockid_t clockid, ktime_t tim) 164 { 165 return tim; 166 } 167 #endif 168 169 struct vdso_data *arch_get_vdso_data(void *vvar_page); 170 171 #endif /* _LINUX_TIMENS_H */ 172