Re: [PATCH V32 19/27] x86/mmiotrace: Lock down the testmmiotrace module

From: Thomas Gleixner
Date: Thu Apr 04 2019 - 03:48:03 EST


On Wed, 3 Apr 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>

Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>