Re: [PATCH v2] init: Do not select DEBUG_KERNEL by default

From: Kees Cook
Date: Thu Apr 11 2019 - 18:26:27 EST


On Thu, Apr 11, 2019 at 3:16 PM Josh Triplett <josh@xxxxxxxxxxxxxxxx> wrote:
>
> On Wed, Apr 10, 2019 at 11:13:52PM -0400, Sinan Kaya wrote:
> > On 4/10/2019 11:02 PM, Josh Triplett wrote:
> > > Then let's fix*that*, and get checkpatch to help enforce it in the future. EXPERT doesn't affect code generation, and neither should this.
> >
> > I think we have to do both. We need to go after the users as well as
> > solve the immediate problem per this patch.
> >
> > As Mathieu identified, CONFIG_DEBUG_KERNEL is being used all over the
> > place and getting subsystem owners to remove let alone add a check
> > to checkpatch is just going to take time.
> >
> > Please let us know if you are OK with this plan.
>
> I'm not OK with this plan. Turning on EXPERT should make the options
> under DEBUG_KERNEL visible; it's a bug that DEBUG_KERNEL affects code
> generation as well.
>
> Proposed alternative plan: let's add a new symbol, something like
> DEBUG_MISC ("Miscellaneous debug code that should be under a more
> specific debug option but isn't"), make it depend on DEBUG_KERNEL and be
> "default DEBUG_KERNEL" but allow itself to be turned off, and then
> mechanically change the small handful of "#ifdef CONFIG_DEBUG_KERNEL" to
> "#ifdef CONFIG_DEBUG_MISC".
>
> Does that sound like an appropriately rapid solution for this bug?

Sure, that sounds fine to me. Sinan can you take care of that for v4?

--
Kees Cook