Re: [GIT] Networking

Linus Torvalds
2015-11-02T21:19:27Z

On Mon, Nov 2, 2015 at 1:16 PM, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
> On Mon, Nov 2, 2015 at 12:34 PM, Andy Lutomirski <luto@kernel.org> wrote:
>>
>> Getting overflow checking right in more complicated cases is a PITA.
>
> No it is not. Not for unsigned values.

Just to clarify. The "oevrflow" test for unsigned subtracts of "a-b"
(it's really an underflow, but whatever) really is just

(b > a)

Really. That's it. Claiming that that is "complicated" and needs a
helper function is not something sane people do. A fifth-grader that
isn't good at math can understand that.

In contrast, nobody sane understands "usub_overflow(a, b, &res)".

So really. Stop making inane arguments.

Linus