> -----Original Message----- > From: Doug Ledford <dledford@xxxxxxxxxx> > Sent: Thursday, December 6, 2018 2:55 PM > To: Parav Pandit <parav@xxxxxxxxxxxx>; Leon Romanovsky > <leon@xxxxxxxxxx> > Cc: Jason Gunthorpe <jgg@xxxxxxxxxxxx>; Mark Zhang > <markz@xxxxxxxxxxxx>; RDMA mailing list <linux-rdma@xxxxxxxxxxxxxxx> > Subject: Re: [PATCH rdma-rc] IB/core: Don't match bond master filter for > closed slaves > > On Thu, 2018-12-06 at 19:10 +0000, Parav Pandit wrote: > > > -----Original Message----- > > > From: Leon Romanovsky <leon@xxxxxxxxxx> > > > Sent: Thursday, December 6, 2018 12:48 PM > > > To: Doug Ledford <dledford@xxxxxxxxxx> > > > Cc: Jason Gunthorpe <jgg@xxxxxxxxxxxx>; Mark Zhang > > > <markz@xxxxxxxxxxxx>; RDMA mailing list > > > <linux-rdma@xxxxxxxxxxxxxxx>; Parav Pandit <parav@xxxxxxxxxxxx> > > > Subject: Re: [PATCH rdma-rc] IB/core: Don't match bond master filter > > > for closed slaves > > > > > > On Thu, Dec 06, 2018 at 12:19:30PM -0500, Doug Ledford wrote: > > > > On Wed, 2018-12-05 at 15:50 +0200, Leon Romanovsky wrote: > > > > > From: Mark Zhang <markz@xxxxxxxxxxxx> > > > > > > > > > > The "modprobe -r mlx4_en" will close bond slaves and in such > > > > > case the rdma_dev would be NULL, so no match should be returned. > > > > > > > > I'm not groking your commit message. What happens without this > patch? > > > > > > We will see calltrace due to the fact that NULL is passed down the > > > stack through rdma_is_upper_dev_rcu() upto > netdev_walk_all_upper_dev_rcu(). > > > > > I see this patch being sent for -rc which I was not sure when I reviewed. > > Commit message needs to change as below. > > > > When mlx4_en driver is unloaded, and configured to use bond devices, > get_netdev() callback returns NULL because associated netdev is > unregistered. > > Therefore, similar to other filter() routines, fix > is_upper_ndev_bond_master_filter() to handle NULL netdev. > > Without this check, a call trace is observed. > > Does it catch a WARN_ON later on, or does it oops? > It is NULL reference oops. > -- > Doug Ledford <dledford@xxxxxxxxxx> > GPG KeyID: B826A3330E572FDD > Key fingerprint = AE6B 1BDA 122B 23B4 265B 1274 B826 A333 0E57 2FDD
