Re: [PATCH net] udp: fix the len check in udp_lib_getsockopt

On 5/28/21 7:47 PM, Xin Long wrote:

The partial byte(or even 0) of the value returned due to passing a wrong
optlen should be considered as an error. "On error, -1 is returned, and
errno is set appropriately.". Success returned in that case only confuses
the user.

It is feasible that some app could use bool or u8 for options that have
0 or 1 values and that code has so far worked. This change would break that.