time: Add do_timens_ktime_to_host() helper (89dd8eec) · Commits · 戴 / test

include/linux/time_namespace.h

+17 −0

Original line number	Diff line number	Diff line
		@@ -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 */

+36 −0

Original line number	Diff line number	Diff line
		@@ -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);