From: "Michael S. Tsirkin" <mst@xxxxxxxxxx> Date: Wed, 5 Jun 2013 12:02:52 +0300 > On Wed, Jun 05, 2013 at 03:40:46PM +0800, Jason Wang wrote: >> When we decide not use zero-copy, msg.control should be set to NULL otherwise >> macvtap/tap may set zerocopy callbacks which may decrease the kref of ubufs >> wrongly. >> >> Bug were introduced by commit cedb9bdce099206290a2bdd02ce47a7b253b6a84 >> (vhost-net: skip head management if no outstanding). >> >> This solves the following warnings: >> >> WARNING: at include/linux/kref.h:47 handle_tx+0x477/0x4b0 [vhost_net]() >> Modules linked in: vhost_net macvtap macvlan tun nfsd exportfs bridge stp llc openvswitch kvm_amd kvm bnx2 megaraid_sas [last unloaded: tun] >> CPU: 5 PID: 8670 Comm: vhost-8668 Not tainted 3.10.0-rc2+ #1566 >> Hardware name: Dell Inc. PowerEdge R715/00XHKG, BIOS 1.5.2 04/19/2011 >> ffffffffa0198323 ffff88007c9ebd08 ffffffff81796b73 ffff88007c9ebd48 >> ffffffff8103d66b 000000007b773e20 ffff8800779f0000 ffff8800779f43f0 >> ffff8800779f8418 000000000000015c 0000000000000062 ffff88007c9ebd58 >> Call Trace: >> [<ffffffff81796b73>] dump_stack+0x19/0x1e >> [<ffffffff8103d66b>] warn_slowpath_common+0x6b/0xa0 >> [<ffffffff8103d6b5>] warn_slowpath_null+0x15/0x20 >> [<ffffffffa0197627>] handle_tx+0x477/0x4b0 [vhost_net] >> [<ffffffffa0197690>] handle_tx_kick+0x10/0x20 [vhost_net] >> [<ffffffffa019541e>] vhost_worker+0xfe/0x1a0 [vhost_net] >> [<ffffffffa0195320>] ? vhost_attach_cgroups_work+0x30/0x30 [vhost_net] >> [<ffffffffa0195320>] ? vhost_attach_cgroups_work+0x30/0x30 [vhost_net] >> [<ffffffff81061f46>] kthread+0xc6/0xd0 >> [<ffffffff81061e80>] ? kthread_freezable_should_stop+0x70/0x70 >> [<ffffffff817a1aec>] ret_from_fork+0x7c/0xb0 >> [<ffffffff81061e80>] ? kthread_freezable_should_stop+0x70/0x70 >> >> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx> > > Good catch. > > Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx> > > This needs to go into stable as well. Applied and queued up for -stable. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
