Re: [net-intel-i40e] question about assignment overwrite

[Gustavo A. R. Silva]

Hi Jeff,

Quoting Jeff Kirsher <jeffrey.t.kirsher@xxxxxxxxx>:

> On Wed, 2017-05-17 at 15:48 -0500, Gustavo A. R. Silva wrote:
> > While looking into Coverity ID 1408956 I ran into the following
> > pieceÂÂ
> > of code at drivers/net/ethernet/intel/i40e/i40e_main.c:8807:
> >
> > 8807ÂÂÂÂÂÂÂ if (pf->hw.mac.type == I40E_MAC_X722) {
> > 8808ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ pf->flags |= I40E_FLAG_RSS_AQ_CAPABLE
> > 8809ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ | I40E_FLAG_128_QP_RSS_CAPABLE
> > 8810ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ | I40E_FLAG_HW_ATR_EVICT_CAPABLE
> > 8811ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ | I40E_FLAG_OUTER_UDP_CSUM_CAPABLE
> > 8812ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ | I40E_FLAG_WB_ON_ITR_CAPABLE
> > 8813ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ |
> > I40E_FLAG_MULTIPLE_TCP_UDP_RSS_PCTYPE
> > 8814ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ | I40E_FLAG_NO_PCI_LINK_CHECK
> > 8815ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ | I40E_FLAG_USE_SET_LLDP_MIB
> > 8816ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ | I40E_FLAG_GENEVE_OFFLOAD_CAPABLE
> > 8817ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ | I40E_FLAG_PTP_L4_CAPABLE
> > 8818ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ | I40E_FLAG_WOL_MC_MAGIC_PKT_WAKE;
> > 8819ÂÂÂÂÂÂÂ } else if ((pf->hw.aq.api_maj_ver > 1) ||
> > 8820ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ ((pf->hw.aq.api_maj_ver == 1) &&
> > 8821ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ (pf->hw.aq.api_min_ver > 4))) {
> > 8822ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ /* Supported in FW API version higher than 1.4 */
> > 8823ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ pf->flags |= I40E_FLAG_GENEVE_OFFLOAD_CAPABLE;
> > 8824ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ pf->flags = I40E_FLAG_HW_ATR_EVICT_CAPABLE;
> > 8825ÂÂÂÂÂÂÂ } else {
> > 8826ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ pf->flags = I40E_FLAG_HW_ATR_EVICT_CAPABLE;
> > 8827ÂÂÂÂÂÂÂ }
> >
> > The issue here is that the assignment at line 8823 is overwritten
> > byÂÂ
> > the code at line 8824.
> >
> > I'm suspicious that line 8824 should be remove and a patch like theÂÂ
> > following can be applied:
> >
> > index d5c9c9e..48ffa73 100644
> > --- a/drivers/net/ethernet/intel/i40e/i40e_main.c
> > +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
> > @@ -8821,7 +8821,6 @@ static int i40e_sw_init(struct i40e_pf *pf)
> > ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ (pf->hw.aq.api_min_ver > 4))) {
> > ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ /* Supported in FW API version higher than 1.4 */
> > ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ pf->flags |= I40E_FLAG_GENEVE_OFFLOAD_CAPABLE;
> > -ÂÂÂÂÂÂÂÂÂÂÂÂÂÂ pf->flags = I40E_FLAG_HW_ATR_EVICT_CAPABLE;
> > ÂÂÂÂÂÂÂÂ } else {
> > ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ pf->flags = I40E_FLAG_HW_ATR_EVICT_CAPABLE;
> > ÂÂÂÂÂÂÂÂ }
> >
> > What do you think?
>
> This issue is already fixed in my dev-queue branch on my next-queue
> tree.

Great, it's good to know.

Thanks!
--
Gustavo A. R. Silva