Re: [PATCH] usbnet: Fix two races between usbnet_stop() and the BH

On Mon, 2015-08-24 at 14:21 -0400, Alan Stern wrote:

quoted

In theory, an architecture could implement atomic bit operations

using 

quoted

a spinlock to insure atomicity.  I don't know if any architectures

do 

quoted

this, but if they do then the scenario above could arise.

Now that I see this in writing, I realize it's not possible after
all.  
clear_bit() et al. will work with a single unsigned long, which
doesn't
leave any place for spinlocks or other mechanisms.  I was thinking of 
atomic_t.

Refuting yourself you are making the assumption that the lock has
to be inside the data structure. That is not true.

	Regards
		Oliver