On Tue, May 7, 2019 at 7:54 PM Jason Wang <jasow...@redhat.com> wrote: > This is only true if you can make sure tfile[tun->numqueues] is not > freed. Either my patch or SOCK_RCU_FREE can solve this, but for > SOCK_RCU_FREE we need do extra careful audit to make sure it doesn't > break someting. So synchronize through pointers in tfiles[] which is > already protected by RCU is much more easier. It can make sure no > dereference from xmit path after synchornize_net(). And this matches the > assumptions of the codes after synchronize_net(). >
It is hard to tell which sock_put() matches with this synchronize_net() given the call path is complicated. With SOCK_RCU_FREE, no such a problem, all sock_put() will be safe. So to me SOCK_RCU_FREE is much easier to understand and audit. Thanks.
