diff --git a/include/linux/ktime.h b/include/linux/ktime.h index 2b6a204bd8d4..3ffc69ebe967 100644 --- a/include/linux/ktime.h +++ b/include/linux/ktime.h @@ -63,6 +63,13 @@ static inline ktime_t ktime_set(const s64 secs, const unsigned long nsecs) #define ktime_add(lhs, rhs) \ ({ (ktime_t){ .tv64 = (lhs).tv64 + (rhs).tv64 }; }) +/* + * Same as ktime_add(), but avoids undefined behaviour on overflow; however, + * this means that you must check the result for overflow yourself. + */ +#define ktime_add_unsafe(lhs, rhs) \ + ({ (ktime_t){ .tv64 = (u64) (lhs).tv64 + (rhs).tv64 }; }) + /* * Add a ktime_t variable and a scalar nanosecond value. * res = kt + nsval: diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 17f7bcff1e02..1dc94768b5a3 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -312,7 +312,7 @@ EXPORT_SYMBOL_GPL(__ktime_divns); */ ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs) { - ktime_t res = ktime_add(lhs, rhs); + ktime_t res = ktime_add_unsafe(lhs, rhs); /* * We use KTIME_SEC_MAX here, the maximum timeout which we can