Re: [patch V3 05/11] x86/mm/cpa: Add debug mechanism

From: Dave Hansen
Date: Fri Sep 21 2018 - 12:40:54 EST


On 09/17/2018 07:29 AM, Thomas Gleixner wrote:
> The whole static protection magic is silently fixing up anything which is
> handed in. That's just wrong. The offending call sites need to be fixed.
>
> Add a debug mechanism which emits a warning if a requested mapping needs to be
> fixed up. The DETECT debug mechanism is really not meant to be enabled except
> for developers, so limit the output hard to the protection fixups.
...
> +enum cpa_warn {
> + CPA_PROTECT,
> + CPA_DETECT,
> +};
> +
> +static const int cpa_warn_level = CPA_PROTECT;

Even if this is intended for developers only, should we also add some
config option here so things like 0day can still get warnings out of this?

Reviewed-by: Dave Hansen <dave.hansen@xxxxxxxxx>