Re: [PATCH 169/190] Revert "atl1e: checking the status of atl1e_write_phy_reg"

[Greg Kroah-Hartman]

On Tue, Apr 27, 2021 at 08:13:25PM +0200, Greg Kroah-Hartman wrote:
> On Wed, Apr 21, 2021 at 03:00:44PM +0200, Greg Kroah-Hartman wrote:
> > This reverts commit ff07d48d7bc0974d4f96a85a4df14564fb09f1ef.
> > 
> > Commits from @umn.edu addresses have been found to be submitted in "bad
> > faith" to try to test the kernel community's ability to review "known
> > malicious" changes.  The result of these submissions can be found in a
> > paper published at the 42nd IEEE Symposium on Security and Privacy
> > entitled, "Open Source Insecurity: Stealthily Introducing
> > Vulnerabilities via Hypocrite Commits" written by Qiushi Wu (University
> > of Minnesota) and Kangjie Lu (University of Minnesota).
> > 
> > Because of this, all submissions from this group must be reverted from
> > the kernel tree and will need to be re-reviewed again to determine if
> > they actually are a valid fix.  Until that work is complete, remove this
> > change to ensure that no problems are being introduced into the
> > codebase.
> > 
> > Cc: Kangjie Lu <kjlu@xxxxxxx>
> > Cc: David S. Miller <davem@xxxxxxxxxxxxx>
> > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > ---
> >  drivers/net/ethernet/atheros/atl1e/atl1e_main.c | 4 +---
> >  1 file changed, 1 insertion(+), 3 deletions(-)
> > 
> > diff --git a/drivers/net/ethernet/atheros/atl1e/atl1e_main.c b/drivers/net/ethernet/atheros/atl1e/atl1e_main.c
> > index ff9f96de74b8..85f9cb769e30 100644
> > --- a/drivers/net/ethernet/atheros/atl1e/atl1e_main.c
> > +++ b/drivers/net/ethernet/atheros/atl1e/atl1e_main.c
> > @@ -455,9 +455,7 @@ static void atl1e_mdio_write(struct net_device *netdev, int phy_id,
> >  {
> >  	struct atl1e_adapter *adapter = netdev_priv(netdev);
> >  
> > -	if (atl1e_write_phy_reg(&adapter->hw,
> > -				reg_num & MDIO_REG_ADDR_MASK, val))
> > -		netdev_err(netdev, "write phy register failed\n");
> > +	atl1e_write_phy_reg(&adapter->hw, reg_num & MDIO_REG_ADDR_MASK, val);
> >  }
> >  
> >  static int atl1e_mii_ioctl(struct net_device *netdev,
> > -- 
> > 2.31.1
> > 
> 
> The original change here is a mess, what is a user supposed to do if
> this call fails?  I will revert it and properly pass the error value up
> to the callers, as that is the correct thing to do here, not paper over
> the issue with a commit message that claims this change "fixes"
> anything.

In looking at this further, Du has pointed out to me that the
atl1e_mdio_write function can not easily be changed to return an error
value, because that would require all callbacks for mdio_write in struct
mii_if_info would need to be changed and handled properly.

So the original commit was as correct as is possible at the moment,
making a much larger change like this really isn't needed, so I'll drop
the revert.

thanks to Du Cheng for the additional review, it is much appreciated.

greg k-h