Re: [Patch v7 14/18] x86/speculation: Add 'seccomp' Spectre v2 app to app protection mode

[Thomas Gleixner]

On Tue, 20 Nov 2018, Tim Chen wrote:
> According to software guidance:
> 
> "Setting ... STIBP ... on a logical processor prevents the predicted
> targets of indirect branches on any logical processor of that core
> from being controlled by software that executes (or executed
> previously) on another logical processor of the same core."
> 
> https://software.intel.com/security-software-guidance/insights/deep-dive-single-thread-indirect-branch-predictors
> 
> Hence setting STIBP on a sandboxed task will prevent the task
> from attacking other sibling threads or getting attacked.

That's not sufficient, because you need an IBPB when the sandboxed task is
switched out.

Thanks,

	tglx