Re: CONFIG_MARKERS

Frank Ch. Eigler
2008-01-23T13:21:35Z

Hi -

On Tue, Jan 22, 2008 at 11:17:40PM -0500, Jon Masters wrote:
> On Tue, 2008-01-22 at 22:10 -0500, Mathieu Desnoyers wrote:
> > [...]
> > > > Is this an attempt to not set a marker for proprietary modules? [...]
> > >
> > > I can't seem to find any discussion about this aspect. If this is the
> > > intent, it seems misguided to me. There may instead be a relationship
> > > to TAINT_FORCED_{RMMOD,MODULE}. Mathieu?

> > On my part, its mostly a matter of not crashing the kernel when someone
> > tries to force modprobe of a proprietary module (where the checksums
> > doesn't match) on a kernel that supports the markers. Not doing so
> > causes the markers to try to find the marker-specific information in
> > struct module which doesn't exist and OOPSes.

But you have the wrong target: it is not proprietary modules that have
this risk but those built out-of-tree without checksums. Maybe
oopsing in this case is not so bad; or the check could just limit itself to
FORCED_MODULE.

> > Christoph's point of view is rather more drastic than mine : it's not
> > interesting for the kernel community to help proprietary modules writers,
> > so it's a good idea not to give them marker support. (I CC'ed him so he
> > can clarify his position).
> Right. I thought that was your collective opinion

Another way of looking at this though is that by allowing/encouraging
proprietary module writers to include markers, we and their users get
new diagnostic capabilities. It constitutes a little bit of opening
up, which IMO we should reward rather than punish.

- FChE