Re: [PATCH v7 5/6] x86/signal: Detect and prevent an alternate signal stack overflow

[Andy Lutomirski]

I forgot to mention why I cc'd all you fine Xen folk:

On Thu, Mar 25, 2021 at 11:13 AM Andy Lutomirski <luto@xxxxxxxxxx> wrote:

>
> >         } else if (IS_ENABLED(CONFIG_X86_32) &&
> >                    !onsigstack &&
> >                    regs->ss != __USER_DS &&

This bit here seems really dubious on Xen PV.  Honestly it seems
dubious everywhere, but especially on Xen PV.

--Andy