diff options
| -rw-r--r-- | include/linux/time_namespace.h | 17 | ||||
| -rw-r--r-- | kernel/time/namespace.c | 36 |
2 files changed, 53 insertions, 0 deletions
diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h index d7e3b4994e31..34ee110b5c35 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 */ diff --git a/kernel/time/namespace.c b/kernel/time/namespace.c index c2a58e45fc4b..1a0fbaa5d2d4 100644 --- a/kernel/time/namespace.c +++ b/kernel/time/namespace.c @@ -16,6 +16,42 @@ #include <linux/err.h> #include <linux/mm.h> +ktime_t do_timens_ktime_to_host(clockid_t clockid, ktime_t tim, + struct timens_offsets *ns_offsets) +{ + ktime_t offset; + + switch (clockid) { + case CLOCK_MONOTONIC: + offset = timespec64_to_ktime(ns_offsets->monotonic); + break; + case CLOCK_BOOTTIME: + case CLOCK_BOOTTIME_ALARM: + offset = timespec64_to_ktime(ns_offsets->boottime); + break; + default: + return tim; + } + + /* + * Check that @tim value is in [offset, KTIME_MAX + offset] + * and subtract offset. + */ + if (tim < offset) { + /* + * User can specify @tim *absolute* value - if it's lesser than + * the time namespace's offset - it's already expired. + */ + tim = 0; + } else { + tim = ktime_sub(tim, offset); + if (unlikely(tim > KTIME_MAX)) + tim = KTIME_MAX; + } + + return tim; +} + static struct ucounts *inc_time_namespaces(struct user_namespace *ns) { return inc_ucount(ns, current_euid(), UCOUNT_TIME_NAMESPACES); |