On Wed, Nov 30, 2016 at 1:16 AM, Richard Guy Briggs <r...@redhat.com> wrote: > On 2016-11-29 09:14, Cong Wang wrote: >> netlink kernel socket is protected by refcount, not RCU. >> Its rcv path is neither protected by RCU. So the synchronize_net() >> is just pointless. > > If I understand correctly, xfrm_user_net_exit() usage of > RCU_INIT_POINTER() and synchronize_net() is similarly pointless? Also > net/phonet/socket.c? I probably modelled things based on the former...
Possibly, but xfrm case is slightly different, it has two copies of the pointer to the netlink socket, also it uses exit_batch(). I need to double check. Take a look at better examples, fib_front, genetlink, rtnetlink.
