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. > 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? regards, dan carpenter
