[dpdk-dev] [PATCH] net/i40e: fix param check to avoid division by 0

wang.yong19 at zte.com.cn wang.yong19 at zte.com.cn
Tue Jun 20 09:48:15 CEST 2017


 > RE: [PATCH] net/i40e: fix param check to avoid division by 0
> 
> 
> 
> > -----Original Message-----
> > From: Yong Wang [mailto:wang.yong19 at zte.com.cn]
> > Sent: Monday, June 12, 2017 5:07 PM
> > To: Zhang, Helin <helin.zhang at intel.com>; Wu, Jingjing 
> <jingjing.wu at intel.com>
> > Cc: dev at dpdk.org; Yong Wang <wang.yong19 at zte.com.cn>
> > Subject: [PATCH] net/i40e: fix param check to avoid division by 0
> > 
> > In function i40e_vsi_config_tc_queue_mapping(), if 'enabled_tcmap' is
> > 0, 'total_tc' might be 0. Then 'total_tc' might be used in a division
> > by 0 in "qpnum_per_tc = i40e_align_floor(vsi->nb_qps / total_tc)". Fix
> > it by adding a check to parameter 'enabled_tcmap'.
> > 
> > Signed-off-by: Yong Wang <wang.yong19 at zte.com.cn>
> > ---
> >  drivers/net/i40e/i40e_ethdev.c | 5 +++++
> >  1 file changed, 5 insertions(+)
> > 
> > diff --git a/drivers/net/i40e/i40e_ethdev.c 
b/drivers/net/i40e/i40e_ethdev.c
> > index c18a93b..d41b213 100644
> > --- a/drivers/net/i40e/i40e_ethdev.c
> > +++ b/drivers/net/i40e/i40e_ethdev.c
> > @@ -4257,6 +4257,11 @@ enum i40e_status_code
> >     int i, total_tc = 0;
> >     uint16_t qpnum_per_tc, bsf, qp_idx;
> > 
> > +   if (enabled_tcmap == 0) {
> > +      PMD_DRV_LOG(ERR, "Error! enabled tcmap shouldn't be 0");
> > +      return I40E_ERR_PARAM;
> > +   }
> > +
> >     ret = validate_tcmap_parameter(vsi, enabled_tcmap);
> >     if (ret != I40E_SUCCESS)
> >        return ret;
> > --
> Thanks for the fix.
> 
> Could you add the check in func validate_tcmap_parameter?
> 
> Thanks
> Jingjing
> 
> 
  Since func validate_tcmap_parameter() was called by 3 func, if I add 
the check to func validate_tcmap_parameter(), I am not sure whether it 
will impact the other two callers who didn't meet division by 0.
  Or should I fix it by changing 'total_tc' from 0 to 1 just as func 
i40e_vsi_update_queue_mapping() does?

Thanks
Yong



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