Commit d004e024 authored Nov 14, 2011 by Hector Palacios Committed by John Stultz Nov 17, 2011

timekeeping: add arch_offset hook to ktime_get functions



ktime_get and ktime_get_ts were calling timekeeping_get_ns()
but later they were not calling arch_gettimeoffset() so architectures
using this mechanism returned 0 ns when calling these functions.

This happened for example when running Busybox's ping which calls
syscall(__NR_clock_gettime, CLOCK_MONOTONIC, ts) which eventually
calls ktime_get. As a result the returned ping travel time was zero.

CC: stable@kernel.org
Signed-off-by: Hector Palacios <hector.palacios@digi.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>

parent 367177e5

kernel/time/timekeeping.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -249,6 +249,8 @@ ktime_t ktime_get(void)
		secs = xtime.tv_sec + wall_to_monotonic.tv_sec;
		nsecs = xtime.tv_nsec + wall_to_monotonic.tv_nsec;
		nsecs += timekeeping_get_ns();
		/* If arch requires, add in gettimeoffset() */
		nsecs += arch_gettimeoffset();

		} while (read_seqretry(&xtime_lock, seq));
		/*
		@@ -280,6 +282,8 @@ void ktime_get_ts(struct timespec *ts)
		*ts = xtime;
		tomono = wall_to_monotonic;
		nsecs = timekeeping_get_ns();
		/* If arch requires, add in gettimeoffset() */
		nsecs += arch_gettimeoffset();

		} while (read_seqretry(&xtime_lock, seq));