Re: [RFC PATCH] x86: Make sure verify_cpu has a good stack

From: Borislav Petkov
Date: Wed Mar 02 2016 - 11:15:44 EST


On Wed, Mar 02, 2016 at 05:55:14PM +0200, Mika Penttilà wrote:
> > + /* Setup a stack for verify_cpu */
> > + movq stack_start - __START_KERNEL_map, %rsp
> > + subq $__START_KERNEL_map, %rsp
> > +
>
> You subtract __START_KERNEL_map twice ?

Yes. That's not very obvious and it took me a while. I probably should
add a comment.

Want to stare at it a little bit more and try to figure it out or should
I explain?

:-)

--
Regards/Gruss,
Boris.

ECO tip #101: Trim your mails when you reply.