Re: [PATCH V34 20/29] x86/mmiotrace: Lock down the testmmiotrace module

[Thomas Gleixner]

On Fri, 21 Jun 2019, Matthew Garrett wrote:

> From: David Howells <dhowells@xxxxxxxxxx>
> 
> The testmmiotrace module shouldn't be permitted when the kernel is locked
> down as it can be used to arbitrarily read and write MMIO space. This is
> a runtime check rather than buildtime in order to allow configurations
> where the same kernel may be run in both locked down or permissive modes
> depending on local policy.
> 
> Suggested-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Signed-off-by: David Howells <dhowells@xxxxxxxxxx
> Signed-off-by: Matthew Garrett <mjg59@xxxxxxxxxx>
> cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
> cc: Ingo Molnar <mingo@xxxxxxxxxx>
> cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
> cc: x86@xxxxxxxxxx

Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>