time: Add do_timens_ktime_to_host() helper
The helper subtracts namespace's clock offset from the given time
and ensures that the result is within [0, KTIME_MAX].
Co-developed-by: Dmitry Safonov <[email protected]>
Signed-off-by: Andrei Vagin <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h
index d7e3b49..34ee110 100644
--- a/include/linux/time_namespace.h
+++ b/include/linux/time_namespace.h
@@ -59,6 +59,19 @@ static inline void timens_add_boottime(struct timespec64 *ts)
*ts = timespec64_add(*ts, ns_offsets->boottime);
}
+ktime_t do_timens_ktime_to_host(clockid_t clockid, ktime_t tim,
+ struct timens_offsets *offsets);
+
+static inline ktime_t timens_ktime_to_host(clockid_t clockid, ktime_t tim)
+{
+ struct time_namespace *ns = current->nsproxy->time_ns;
+
+ if (likely(ns == &init_time_ns))
+ return tim;
+
+ return do_timens_ktime_to_host(clockid, tim, &ns->offsets);
+}
+
#else
static inline struct time_namespace *get_time_ns(struct time_namespace *ns)
{
@@ -88,6 +101,10 @@ static inline int timens_on_fork(struct nsproxy *nsproxy,
static inline void timens_add_monotonic(struct timespec64 *ts) { }
static inline void timens_add_boottime(struct timespec64 *ts) { }
+static inline ktime_t timens_ktime_to_host(clockid_t clockid, ktime_t tim)
+{
+ return tim;
+}
#endif
#endif /* _LINUX_TIMENS_H */
