diff options
| -rw-r--r-- | kernel/time/timekeeping.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 26e2f3705cc1..f5e362f12fe2 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -168,8 +168,15 @@ int __read_mostly timekeeping_suspended; static struct timespec xtime_cache __attribute__ ((aligned (16))); void update_xtime_cache(u64 nsec) { - xtime_cache = xtime; - timespec_add_ns(&xtime_cache, nsec); + /* + * Use temporary variable so get_seconds() cannot catch + * an intermediate xtime_cache.tv_sec value. + * The ACCESS_ONCE() keeps the compiler from optimizing + * out the intermediate value. + */ + struct timespec ts = xtime; + timespec_add_ns(&ts, nsec); + ACCESS_ONCE(xtime_cache) = ts; } /* must hold xtime_lock */ |