On Thu, Mar 28, 2013 at 01:49:24AM +0100, David Herrmann wrote:

+	spin_lock_irq(&dev->event_lock);
+	spin_lock(&client->buffer_lock);
+
+	ret = bits_to_user(bits, max, size, p, compat);

This copies data to userspace and thus may sleep. You can not hold spinlocks
here.

I think you need to collect the data, flush the events and then try
copying the data out. If we fail on copying data out - too bad. Maybe we
can stuff SYN_DROPPED in the queue, but it is not really necessary.

Thanks.

-- 
Dmitry