Re: [PATCH v2] x86, mem: move memmove to out of line assembler

From: Kees Cook
Date: Tue Sep 27 2022 - 16:36:37 EST


On Tue, Sep 27, 2022 at 01:01:35PM -0700, Nick Desaulniers wrote:
> > Found it (need to use %di instead of %dx). With this changed, the kunit
> > test passes again:
> >
>
> That was stupid of me, I updated the scratch register operand in the
> instruction 2 before the one at issue and forgot to update the operand
> for the register in question, breaking the swap.

No worries! It meant I got to do a very careful review of the port. :)

> Off thread, can you show me how to run the kunit tests, please?

It's literally just what I put in the original email. KUnit is super
easy to use. In the root of the kernel source tree, just run:

./tools/testing/kunit/kunit.py run --arch=i386 memcpy

Without --arch, it'll default to um.

--
Kees Cook