Re: [PATCH] ibmvnic: Use -EBUSY in __ibmvnic_reset()

[Dan Carpenter]

On Tue, Apr 23, 2024 at 12:54:55PM +0200, Paolo Abeni wrote:
> On Fri, 2024-04-19 at 16:08 +0200, Markus Elfring wrote:
> > From: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
> > Date: Fri, 19 Apr 2024 15:46:17 +0200
> > 
> > Add a minus sign before the error code “EBUSY”
> > so that a negative value will be used as in other cases.
> > 
> > This issue was transformed by using the Coccinelle software.
> > 
> > Signed-off-by: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
> > ---
> >  drivers/net/ethernet/ibm/ibmvnic.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
> > index 5e9a93bdb518..737ae83a836a 100644
> > --- a/drivers/net/ethernet/ibm/ibmvnic.c
> > +++ b/drivers/net/ethernet/ibm/ibmvnic.c
> > @@ -3212,7 +3212,7 @@ static void __ibmvnic_reset(struct work_struct *work)
> >  		    adapter->state == VNIC_REMOVED) {
> >  			spin_unlock_irqrestore(&adapter->state_lock, flags);
> >  			kfree(rwi);
> > -			rc = EBUSY;
> > +			rc = -EBUSY;
> >  			break;
> > 
> 
> AFAICS the error is always used as bool, so this will not change any
> behavior in practice. I tend to think we should not merge this kind of
> change outside some larger work in the same area, but I'd love a second
> opinion from the driver owners.

I missed the original patch due to my procmail filters...

You're right that it doesn't affect the behavior of the driver except
for the debug output when we do:

	netdev_dbg(adapter->netdev, "Reset failed, rc=%d\n", rc);

But the - was left off uninitentionally so I think we should apply it.

I have been trying to look for similar bugs where the - is left off.
It's a bit challenging because there places where we use positive
error codes deliberately.  But in this case a static checker could
easily detect the bug with a low false positive ratio by saying, "We're
mixing normal negative error codes with positive EBUSY".

regards,
dan carpenter