1 files changed, 25 insertions, 0 deletions
diff --git a/kernel/time/time.c b/kernel/time/time.c
index a4064b6..cb1f83e 100644
--- a/kernel/time/time.c
+++ b/kernel/time/time.c
@@ -769,3 +769,28 @@ struct timespec timespec_add_safe(const struct timespec lhs,
 
 	return res;
 }
+
+#if __BITS_PER_LONG != 64
+
+/*
+ * Add two timespec64 values and do a safety check for overflow.
+ * It's assumed that both values are valid (>= 0).
+ * And, each timespec64 is in normalized form.
+ */
+struct timespec64 timespec64_add_safe(const struct timespec64 lhs,
+				const struct timespec64 rhs)
+{
+	struct timespec64 res;
+
+	set_normalized_timespec64(&res, lhs.tv_sec + rhs.tv_sec,
+			lhs.tv_nsec + rhs.tv_nsec);
+
+	if (unlikely(res.tv_sec < lhs.tv_sec || res.tv_sec < rhs.tv_sec)) {
+		res.tv_sec = TIME64_MAX;
+		res.tv_nsec = 0;
+	}
+
+	return res;
+}
+
+#endif