Re: Question about the export of symbol lockdep_init_map

[Peter Zijlstra <peterz@infradead.org>]

On Sun, 2012-06-24 at 12:41 -0500, Larry Finger wrote:
> Ingo,
> 
> when you added the locking correctness validator code in commit fbb9ce95, you 
> exported lockdep_init_map() with EXPORT_SYMBOL_GPL. This choice is causing a 
> problem with the latest version of Broadcom's hybrid wl driver. Although I do 
> not agree with their policies regarding drivers with binary blobs, there are 
> some devices such as the BCM43228 (14e4:4359) for which no open-source driver is 
> yet available. As a result, owners of such devices are forced to use solutions 
> such as ndiswrapper, which is worse than using wl.
> 
> would you accept the following patch?
> 
> Index: wireless-testing/kernel/lockdep.c
> ===================================================================
> --- wireless-testing.orig/kernel/lockdep.c
> +++ wireless-testing/kernel/lockdep.c
> @@ -2994,7 +2994,7 @@ void lockdep_init_map(struct lockdep_map
>          if (subclass)
>                  register_lock_class(lock, subclass, 1);
>   }
> -EXPORT_SYMBOL_GPL(lockdep_init_map);
> +EXPORT_SYMBOL(lockdep_init_map);
> 
>   struct lock_class_key __lockdep_no_validate__;
> 

I can't speak for Ingo, but I would object to it. Owners of such devices
can send them back to wherever they got them from and demand a refund.

Loading binary blobs pretty much wrecks your kernel validation anyway,
who knows what they do.