Hi Dan, > -----Original Message----- > From: Dan Carpenter <dan.carpenter@xxxxxxxxxx> > Sent: Tuesday, April 23, 2019 10:50 AM > To: Parav Pandit <parav@xxxxxxxxxxxx> > Cc: Leon Romanovsky <leon@xxxxxxxxxx>; Eli Cohen <eli@xxxxxxxxxxxx>; > Doug Ledford <dledford@xxxxxxxxxx>; Jason Gunthorpe <jgg@xxxxxxxx>; > linux-rdma@xxxxxxxxxxxxxxx; kernel-janitors@xxxxxxxxxxxxxxx > Subject: Re: [PATCH] IB/mlx5: add checking for "vf" from do_setvfinfo() > > On Mon, Apr 22, 2019 at 03:09:00PM +0000, Parav Pandit wrote: > > Hi Dan, > > > > > -----Original Message----- > > > From: Dan Carpenter <dan.carpenter@xxxxxxxxxx> > > > Sent: Monday, April 22, 2019 3:09 AM > > > To: Parav Pandit <parav@xxxxxxxxxxxx> > > > Cc: Leon Romanovsky <leon@xxxxxxxxxx>; Eli Cohen > <eli@xxxxxxxxxxxx>; > > > Doug Ledford <dledford@xxxxxxxxxx>; Jason Gunthorpe <jgg@xxxxxxxx>; > > > linux-rdma@xxxxxxxxxxxxxxx; kernel-janitors@xxxxxxxxxxxxxxx > > > Subject: Re: [PATCH] IB/mlx5: add checking for "vf" from > > > do_setvfinfo() > > > > > > On Tue, Apr 16, 2019 at 10:54:42PM +0000, Parav Pandit wrote: > > > > > Yeah. But the call tree here is: > > > > > > > > > > do_setvfinfo() > > > > > -> ops->ndo_get_vf_config() > > > > > -> rtnl_fill_vfinfo() > > > > > -> dev->netdev_ops->ndo_get_vf_config(dev, vfs_num, &ivi) > > > > > -> ipoib_get_vf_config() > > > > > -> ib_get_vf_config > > > > > -> device->ops.get_vf_config(device, vf, port, > > > > > info); > > > > > > > > > > Changing the ->ndo_get_vf_config() pointer means you have to > > > > > update > > > > > 20 functions in various drivers. It becomes quite involved. We > > > > > should apply this simple self contained fix then worry about > > > > > doing other > > > cleanups later. > > > > > > > > > But if a static checker is run on following functions, they need > > > > for vf < 0 > > > check. > > > > > > > > i40e_ndo_get_vf_config > > > > mlx5e_get_vf_config > > > > bnxt_get_vf_config > > > > etc and few more. > > > > > > I checked again to see if it was "20 functions" or if it was "etc > > > and few more"... It turns out its only 18 functions because I > > > double counted two functions at first. Here is the list: > > > > > > be_get_vf_config > > > bnx2x_get_vf_config > > > bnxt_get_vf_config > > > cxgb4_mgmt_get_vf_config > > > efx_sriov_get_vf_config > > > fm10k_ndo_get_vf_config > > > i40e_ndo_get_vf_config > > > ice_get_vf_cfg > > > igb_ndo_get_vf_config > > > ipoib_get_vf_config > > > ixgbe_ndo_get_vf_config > > > liquidio_get_vf_config > > > mlx4_en_get_vf_config > > > mlx5e_get_vf_config > > > nfp_app_get_vf_config > > > nsim_get_vf_config > > > qede_get_vf_config > > > qlcnic_sriov_get_vf_config > > > > > > But you also have to update the call tress as well... It's really > > > very involved. I seriously did look at how to do this and the > > > original patch is the Right Thing To Do [tm]. I've probably sent > > > around 92 underflow patches and sometimes I would definitely agree > > > with you that changing the type is the right fix but not in this case. > > > > > Do you plan to fix all the above functions for < 0? > > There are other several other ndo_get_vf_* functions who need < 0 check. > What about them? > > Will you fix them as well? > > Oh wow... I'm looking at these now and there are a lot of bugs. You are > right. To be honest, though, I'm tempted to just add a check for negatives in > the core... I know you don't like that... > > My static analysis was supposed to catch these underflows. It's the end of > the day for me, but I will get this working tomorrow. > We just make num_vfs to u32 in core and in drivers. This will eliminate < 0 check. From user space value coming is u32 via netlink. This makes things clear, forward looking. > > Instead of doing all those fixes, why not use right u32 data type to > eliminate < 0 check? > > > > What about sriov getting disabled right after > vf check passes? > > I don't know the subsystem well enough to answer this question. What do > you suggest? > I don't think > num_vfs check is needed. Device is expected to fail commands for VFs which are not valid.
