Re: [linux-usb-devel] Bug creating USB endpoints in 2.6.20.x (kernel bug 8198)

[Tejun Heo <htejun@gmail.com>]

Greg KH wrote:
> On Wed, May 09, 2007 at 03:30:41PM +0200, Tejun Heo wrote:
>> Chris Rankin wrote:
>>> --- Tejun Heo <htejun@gmail.com> wrote:
>>>> So, we can fix the problem Chris is seeing by breaking module unload (by
>>>> allowing it to unload too early).  It doesn't sound too hot but module
>>>> unloading race is much less likely than sysfs node deletion/open race.
>>> Yikes! Just temporary breakage, I hope :-)!! The only modules I unload on a regular basis these
>>> days are things like "microcode", which the init scripts take care of as part of the boot-up
>>> process.
>> Okay, here's a half-assed fix.  With this patch applied, if you try to
>> unload a module while you're opening it's dev attribute, kernel will
>> oops later when the file is accessed or closed later but it should fix
>> the bug winecfg triggers.  I really dunno how to fix this the right way
>> in the stable kernel.  Better ideas?  Anyone?
> 
> This looks like the correct fix, the only reason I made this dynamic was
> to properly set up the module owner.  And now that you have removed that
> link in your sysfs rework, it can go and become static again.
> 
> Oh, and this isn't a "device node", it's just a text file that contains
> the major:minor number for a device node to be created from.
> 
> So, care to fix up the class code too and send a patch with a
> signed-off-by:?

I think the proper fix for -stable is to free the structure in
device_release().  I asked Chris to test it.  After he confirms, I'll
send a proper patch with S-O-B.

For -mm, yeap, we can simply make the whole thing static.  I'll send
patch for that soon.

Thanks.

-- 
tejun