On Sun, 2012-07-08 at 19:27 +0300, Arik Nemtsov wrote: > On Sat, Jul 7, 2012 at 12:05 AM, Johannes Berg > <johannes@xxxxxxxxxxxxxxxx> wrote: > > From: Johannes Berg <johannes.berg@xxxxxxxxx> > > > > Making the scan_sdata pointer usable with RCU makes > > it possible to dereference it in the RX path to see > > if a received frame actually matches the interface > > that is scanning. This is just preparations, making > > the pointer __rcu. > > I noticed no synchronize_rcu() in the start/stop scan calls. Good/bad idea? Well, start() certainly wouldn't need it since you'd only get NULL :-) stop() in theory could use it, but it doesn't actually matter because as long as the interface still exists the pointer is valid. We don't free the interface in scan stop, so we don't need to make sure that the pointer is cleared before we continue. And in the case that we *do* in fact clear the interface (when it's going down) we have synchronize_rcu already in those code paths due to say the interface list with RCU protection. johannes -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
