Re: [PATCH] fix bad locking in drivers/base/driver.c

[Greg KH <greg@kroah.com>]

On Tue, Jan 25, 2005 at 08:27:15AM -0800, Linus Torvalds wrote:
> 
> 
> Hmm.. I certainly like the "use completions" patch, since it makes it a
> lot more obvious what is going on (and it is what completions were
> designed for).
> 
> However, since it does change semantics very subtly: if you call
> "driver_unregister()" twice (which is wrong, but looking at the code it
> looks like it would just silently have worked), the old code would just
> ignore it. The new code will block on the second one.
> 
> Now, I don't mind the blocking (it's a bug to call it twice, and blocking
> should even give a nice callback when you do the "show tasks"  sysrq, so
> it's a good way to _find_ the bug), but together with Mike's comment about
> "Compile-tested only", I'd really like somebody (Greg?) to say "trying to
> doubly remove the driver is so illegal that we don't care, and btw, I
> tested it and it's all ok".

I will add it to my queue of patches for the driver core, and test it
out accordingly before trying it out in the -mm tree for a while.

thanks,

greg k-h