David Miller <da...@davemloft.net> wrote: > From: Florian Westphal <f...@strlen.de> > Date: Fri, 29 Sep 2017 13:21:50 +0200 > > > @@ -1488,7 +1484,7 @@ static void netdev_release(struct device *d) > > > > BUG_ON(dev->reg_state != NETREG_RELEASED); > > > > - kfree(dev->ifalias); > > + kfree(rcu_access_pointer(dev->ifalias)); > > netdev_freemem(dev); > > } > > > > "kfree_rcu()" at least? > > If the deal is that you don't need to do and RCU free because > netdevice objects disappear synchronously, and you can therefore prove > that no RCU based async access can occur to dev->ifalias, then you > need to add a comment here.
Ok, I will add a comment. netdev_release gets called via kobject_put() if this was last reference to the device. At that point the device has already been removed from all lists (and private destructor was invoked too). Also, netdev_freemem frees the net_device memory immediately so no other cpu is allowed to use dev at this point.
