Re: [PATCH] x86/bugs: protect against userspace-userspace spectreRSB

From: Linus Torvalds
Date: Wed Jul 25 2018 - 13:28:14 EST


On Tue, Jul 24, 2018 at 12:53 PM Jiri Kosina <jikos@xxxxxxxxxx> wrote:
>
> Mitigate userspace-userspace attacks by always unconditionally filling RSB on
> context switch when generic spectrev2 mitigation has been enabled.

Shouldn't this also do something like

x86_spec_ctrl_base |= x86_spec_ctrl_mask & SPEC_CTRL_STIBP;

if we have HT enabled?

Linus