On Wed, Mar 7, 2018 at 2:08 AM, Laurent Vivier <laur...@vivier.eu> wrote:
>> +static inline int guest_range_valid(unsigned long start, unsigned long len)
>> +{
>> + if (len)
>> + return guest_addr_valid(len - 1) && start <= GUEST_ADDR_MAX - len +
>> 1;
>> + else
>> + return guest_addr_valid(start);
>> +}
>
> I think we can consider len == 0 is invalid and use only:
>
> return start + (len - 1) <= GUEST_ADDR_MAX;
start + len - 1 may wrap around, that's why I first validate len and then have
len at the right side of the comparison. I.e. if we drop check for len == 0 I'd
still write it as
guest_addr_valid(len - 1) && start <= GUEST_ADDR_MAX - len + 1;
--
Thanks.
-- Max
