-
由 Sowmini Varadhan 提交于
Order of initialization in rds_tcp_init needs to be done so that resources are set up and destroyed in the correct synchronization sequence with both the data path, as well as netns create/destroy path. Specifically, - we must call register_pernet_subsys and get the rds_tcp_netid before calling register_netdevice_notifier, otherwise we risk the sequence 1. register_netdevice_notifier sets up netdev notifier callback 2. rds_tcp_dev_event -> rds_tcp_kill_sock uses netid 0, and finds the wrong rtn, resulting in a panic with string that is of the form: BUG: unable to handle kernel NULL pointer dereference at 000000000000000d IP: rds_tcp_kill_sock+0x3a/0x1d0 [rds_tcp] : - the rds_tcp_incoming_slab kmem_cache must be initialized before the datapath starts up. The latter can happen any time after the pernet_subsys registration of rds_tcp_net_ops, whose -> init function sets up the listen socket. If the rds_tcp_incoming_slab has not been set up at that time, a panic of the form below may be encountered BUG: unable to handle kernel NULL pointer dereference at 0000000000000014 IP: kmem_cache_alloc+0x90/0x1c0 : rds_tcp_data_recv+0x1e7/0x370 [rds_tcp] tcp_read_sock+0x96/0x1c0 rds_tcp_recv_path+0x65/0x80 [rds_tcp] : Signed-off-by: NSowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
16c09b1c