Re: [PATCH V2 resend] ipv6: fix incorrect route 'expires' value passed to userspace

On 07/20/2012 06:32 PM, David Laight wrote:

quoted

-	else if (rt->dst.expires - jiffies < INT_MAX)
-		expires = rt->dst.expires - jiffies;
+	else if ((long)rt->dst.expires - (long)jiffies > INT_MIN
+			&& (long)rt->dst.expires - (long)jiffies <

INT_MAX)

quoted

+		expires = (long)rt->dst.expires - (long)jiffies;
 	else
-		expires = INT_MAX;
+		expires = time_is_after_jiffies(rt->dst.expires) ?

INT_MAX : INT_MIN;

I can't help feeling there is a better way to do this.
Maybe:
	long expires = rt->dst.expires - jiffies;
	if (expires != (int)expires)
		expires = expires > 0 ? INT_MAX : INT_MIN;
Although maybe -INT_MAX instead of INT_MIN.

	David

Thanks David, your code looks much cleaner and can archieve the same
function except we should use
	long expires = (long)rt->dst.expires - (long)jiffies;
to avoid the wrapping of jiffies.

Thanks, 
Wei