Re: [RFC PATCH v9 18/27] x86/cet/shstk: Introduce WRUSS instruction

From: Yu-cheng Yu
Date: Thu Mar 05 2020 - 13:39:12 EST


On Tue, 2020-02-25 at 13:10 -0800, Kees Cook wrote:
> On Wed, Feb 05, 2020 at 10:19:26AM -0800, Yu-cheng Yu wrote:
> > WRUSS is a new kernel-mode instruction but writes directly to user Shadow
> > Stack (SHSTK) memory. This is used to construct a return address on SHSTK
> > for the signal handler.
> >
> > This instruction can fault if the user SHSTK is not valid SHSTK memory.
> > In that case, the kernel does a fixup.
>
> Since these functions aren't used in this patch, should this get merged
> with patch 19?

Yes, I can do that.

Yu-cheng