On Tue, Nov 25, 2014 at 4:02 PM, Ben Pfaff <b...@nicira.com> wrote: > On Tue, Nov 25, 2014 at 04:01:40PM -0800, Alex Wang wrote: > > On current master, the 'struct dp_netdev_port' is destroyed > > immediately when the ref count reaches 0. However, non-pmd > > threads calling the dpif_netdev_execute() for sending packets > > could hold pointer to 'port' that is not ref-counted. Thusly > > those threads could possibly access freed memory when the port > > is deleted. > > > > To fix this bug, this commit makes non-pmd threads acquiring > > the 'port_mutex' before doing the actual execution in > > dpif_netdev_execute(). > > > > Signed-off-by: Alex Wang <al...@nicira.com> > > I don't know this code well enough to review it, but I hope that > there's a proper lock ordering discipline so that this fix doesn't > introduce a deadlock? > >
Hey Ben, Yeah, I discussed this issue with Pravin and found that using lock could be more efficient than calling ovsrcu_synchronize. I checked the code, and at this time, the "port_mutex" is only acquired for port add/del/name query (only main thread deals with the mutex). So, there should be no double locking. I'll ask Pravin for review, Thanks, Alex Wang, _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
