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>

1 files changed, 4 insertions, 0 deletions

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index e9f60d31143..237841378c0 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -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));