Re: [tip:x86/asm] x86/umip: Add emulation code for UMIP instructions

[Denys Vlasenko]

On 11/08/2017 05:57 PM, Linus Torvalds wrote:
> On Wed, Nov 8, 2017 at 8:53 AM, Denys Vlasenko <dvlasenk@xxxxxxxxxx> wrote:
> > We can postpone enabling UMIP by default by a year or so.
> > By this time, new Wine will be on majority of users' machines.
>
> So you are suggesting we run unnecessarily insecure, only in order to
> not do the emulation that we already have the code for and that the
> patch implements?

We ran insecure in this way for ~25 years.

> Why?

To avoid having to maintain more obscure, rarely executed code.