On Fri, Oct 21, 2016 at 11:39 AM, Joe Stringer <j...@ovn.org> wrote: > On 21 October 2016 at 11:37, Joe Stringer <j...@ovn.org> wrote: >> On 21 October 2016 at 10:55, Pravin B Shelar <pshe...@ovn.org> wrote: >>> On upstream kernel datapath OVS make use of networking devices >>> where networking stack does check if device is UP. following >>> patch adds same check in case of compat tunneling implementation. >>> This check also fixes kernel crash in case vxlan device was >>> brought down by user. >>> >>> CPU: 4 PID: 12988 Comm: handler903 Tainted: >>> RIP: 0010:[<ffffffffa05e5407>] vxlan_xmit_one.constprop.50+0x47/0x1210 >>> [openvswitch] >>> Call Trace: >>> [<ffffffffa05e6625>] rpl_vxlan_xmit+0x55/0x80 [openvswitch] >>> [<ffffffffa05d5ad4>] ovs_vport_send+0x44/0xb0 [openvswitch] >>> [<ffffffffa05c62a5>] do_output+0x65/0x180 [openvswitch] >>> [<ffffffffa05c70dc>] do_execute_actions+0x10c/0x860 [openvswitch] >>> [<ffffffffa05c7870>] ovs_execute_actions+0x40/0x130 [openvswitch] >>> [<ffffffffa05cbb59>] ovs_packet_cmd_execute+0x2c9/0x2f0 [openvswitch] >>> [<ffffffff8155f31d>] genl_family_rcv_msg+0x1cd/0x400 >>> [<ffffffff8155f5e1>] genl_rcv_msg+0x91/0xd0 >>> [<ffffffff8155d549>] netlink_rcv_skb+0xa9/0xc0 >>> [<ffffffff8155da78>] genl_rcv+0x28/0x40 >>> [<ffffffff8155ceba>] netlink_unicast+0x16a/0x210 >>> [<ffffffff8155d277>] netlink_sendmsg+0x317/0x430 >>> [<ffffffff81514fd0>] sock_sendmsg+0xb0/0xf0 >>> [<ffffffff81515409>] ___sys_sendmsg+0x3a9/0x3c0 >>> [<ffffffff815162f1>] __sys_sendmsg+0x51/0x90 >>> [<ffffffff81516342>] SyS_sendmsg+0x12/0x20 >>> [<ffffffff81649609>] system_call_fastpath+0x16/0x1b >>> >>> Reported-by: Huanglili (lee) <huanglili.hu...@huawei.com> >>> Signed-off-by: Pravin B Shelar <pshe...@ovn.org> >> >> I'm not 100% convinced that this solves the issue (or whether this >> affects upstream as well), but it seems like this at least makes it >> significantly less likely to crash - If I understand correctly, >> setting the vxlan port down currently guarantees a crash, whereas this >> patch would mean it either doesn't crash, or it only crashes based on >> a race condition. Specifically, one where the reconfiguration gets >> past the synchronize_net() into ndo_stop() (before clearing IFF_UP) >> while OVS manages to execute all of a flow up until output and >> proceeds past this check before the reconfiguration thread clears it. >> >> Probably the type of test to check this would be running heavy traffic >> through a vxlan port, then toggle the port up and down. >> >> Will you also check upstream? >> >> Anyway, this LGTM so: >> Acked-by: Joe Stringer <j...@ovn.org> > > Hmm, the original reporter said that the issue is not fixed. Perhaps > we should hold off on this?
Yes, I would like to see another solution before merging this patch. _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
