Re: [PATCH] Add note that lockdep is not allowed with non-GPL modules

From: Petr Vandrovec
Date: Tue Jul 04 2006 - 17:20:55 EST


Alexey Dobriyan wrote:
On Tue, Jul 04, 2006 at 10:29:04PM +0200, Petr Vandrovec wrote:

Hi Ingo,
can you add this small notice to the lockdep option ?

Lock dependency infrastructure forces all legacy code which uses lock to now
depend on lockdep_init_map symbol, which is GPL-only. It means that almost
no modules can work on kernel with CONFIG_LOCKDEP set. Let's warn user about
that.


IANIngo, but the warning is already there:
* Proprietary module user probably already knows that major deviations from .config
and kernel its module is released is no-no.

Uh? How it comes? VMware modules work in any kernel configuration and architecture. With exception of vmmon, which contains inline assembly for i386 & x86-64 only. But all configs are supported.

* Would you add similar notice to inotify help text? It also exports
GPL-only symbols doncha know. Would you add such notices to everything
exporting GPL-only symbols?

This is just nonsense. I am not talking about using new API, I'm saying that API which was not GPL-only without lockdep has GPL-only portion with lockdep, and this GPL-only portion is needed by implementation of code which existed before lockdep. To me this looks like unexpected change of kernel API, and as such should be documented and warned about.

vmmon: module license 'unspecified' taints kernel.
vmmon: Unknown symbol lockdep_init_map


+ Do not enable this option if you are using non-GPL modules, or
+ they will fail to load due to missing symbol lockdep_init_map.


Lock validor found a bug in NVidia driver, film at 11.

I have no idea how NVidia managed to work around that problem, but VMware modules suddenly depend on this GPL-only symbol, although nothing in the module sources refers to lockdep (same sources which worked yesterday are being used).
Thanks,
Petr Vandrovec
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