On Fri, Oct 21, 2016 at 11:37 AM, 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. > This patch is not to fix upstream issue but bring in existing upstream check into compatibility code.
> Will you also check upstream? > As discussed offline earlier, I am working on upstream fix. > Anyway, this LGTM so: > Acked-by: Joe Stringer <j...@ovn.org> > Thanks for the review. _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
