Re: [2.6 PATCH/RFC] Firmware loader - fix races and resource dealloocation problems

[Greg KH <greg@kroah.com>]

On Sun, Dec 21, 2003 at 01:37:39AM -0500, Dmitry Torokhov wrote:
> Hi,
> 
> It seems that implementation of the firmware loader is racy as it relies
> on kobject hotplug handler. Unfortunately that handler runs too early,
> before firmware class attributes controlling the loading process, are
> created. This causes firmware loading fail at least half of the times on
> my laptop.

Um, why not have your script wait until the files are present?  That
will remove any race conditions you will have.

> Another problem that I see is that the present implementation tries to free
> some of the allocated resources manually instead of relying on driver model.
> Particularly damaging is freeing fw_priv in request_firmware. Although the
> code calls fw_remove_class_device (which in turns calls 
> class_device_unregister) the freeing of class device and all its attributes
> can be delayed as the attribute files may still be held open by the
> userspace handler or any other program. Subsequent access to these files
> could cause trouble.

Cleanups should happen in the release function.  If the firmware code
doesn't do this, it's wrong.

thanks,

greg k-h