Messages in this thread | ![/](/images/icornerl.gif) | | Date | Mon, 20 Nov 2023 18:55:42 +0100 | Subject | Re: [PATCH iwl-next v3 3/5] i40e: Add helpers to find VSI and VEB by SEID and use them | From | Ivan Vecera <> |
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On 20. 11. 23 12:42, Simon Horman wrote: > On Thu, Nov 16, 2023 at 04:21:12PM +0100, Ivan Vecera wrote: >> Add two helpers i40e_(veb|vsi)_get_by_seid() to find corresponding >> VEB or VSI by their SEID value and use these helpers to replace >> existing open-coded loops. >> >> Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com> >> Signed-off-by: Ivan Vecera <ivecera@redhat.com> > > Hi Ivan, > > some minor feedback from my side. > > ... > >> diff --git a/drivers/net/ethernet/intel/i40e/i40e.h b/drivers/net/ethernet/intel/i40e/i40e.h >> index 1e9266de270b..ca8997d29c02 100644 >> --- a/drivers/net/ethernet/intel/i40e/i40e.h >> +++ b/drivers/net/ethernet/intel/i40e/i40e.h >> @@ -1360,4 +1360,38 @@ static inline struct i40e_pf *i40e_hw_to_pf(struct i40e_hw *hw) >> >> struct device *i40e_hw_to_dev(struct i40e_hw *hw); >> >> +/** >> + * i40e_pf_get_vsi_by_seid - find VSI by SEID >> + * @pf: pointer to a PF > > nit: @seid is missing here > >> + **/ >> +static inline struct i40e_vsi * >> +i40e_pf_get_vsi_by_seid(struct i40e_pf *pf, u16 seid) >> +{ >> + struct i40e_vsi *vsi; >> + int i; >> + >> + i40e_pf_for_each_vsi(pf, i, vsi) >> + if (vsi->seid == seid) >> + return vsi; >> + >> + return NULL; >> +} >> + >> +/** >> + * i40e_pf_get_veb_by_seid - find VEB by SEID >> + * @pf: pointer to a PF > > Ditto > > ... > >> diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c > > ... > >> @@ -14848,23 +14831,16 @@ struct i40e_veb *i40e_veb_setup(struct i40e_pf *pf, u16 flags, >> } >> >> /* make sure there is such a vsi and uplink */ >> - i40e_pf_for_each_vsi(pf, vsi_idx, vsi) >> - if (vsi->seid == vsi_seid) >> - break; >> - >> - if (vsi_idx == pf->num_alloc_vsi && vsi_seid != 0) { >> - dev_info(&pf->pdev->dev, "vsi seid %d not found\n", >> - vsi_seid); >> - return NULL; >> + if (vsi_seid) { >> + vsi = i40e_pf_get_vsi_by_seid(pf, vsi_seid); >> + if (!vsi) { >> + dev_err(&pf->pdev->dev, "vsi seid %d not found\n", >> + vsi_seid); >> + return NULL; >> + } >> } >> - >> if (uplink_seid && uplink_seid != pf->mac_seid) { >> - i40e_pf_for_each_veb(pf, veb_idx, veb) { >> - if (veb->seid == uplink_seid) { >> - uplink_veb = veb; >> - break; >> - } >> - } >> + uplink_veb = i40e_pf_get_veb_by_seid(pf, uplink_seid); >> if (!uplink_veb) { >> dev_info(&pf->pdev->dev, >> "uplink seid %d not found\n", uplink_seid); > > The next part of this function looks like this: > > if (!uplink_veb) { > dev_info(&pf->pdev->dev, > "uplink seid %d not found\n", uplink_seid); > return NULL; > } > } > /* get veb sw struct */ > veb_idx = i40e_veb_mem_alloc(pf); > if (veb_idx < 0) > goto err_alloc; > veb = pf->veb[veb_idx]; > veb->flags = flags; > veb->uplink_seid = uplink_seid; > veb->veb_idx = (uplink_veb ? uplink_veb->idx : I40E_NO_VEB); > veb->enabled_tc = (enabled_tc ? enabled_tc : 0x1); > > /* create the VEB in the switch */ > ret = i40e_add_veb(veb, vsi); > > Smatch complains that vsi may be used uninitialised here. > Which does seem possible to me if vsi_seid is 0.
Yes, the support for floating VEBs is and WAS broken prior this patch and it is fixed by the following patch.
Prior this patch... Let's vsi_seid == 0:
/* make sure there is such a vsi and uplink */ i40e_pf_for_each_vsi(pf, vsi_idx, vsi) if (vsi->seid == vsi_seid) break; -> here vsi_idx == pf->num_alloc_vsi because there cannot be VSI with SEID == 0... and VSI points after the pf->vsi[] array.
if (vsi_idx == pf->num_alloc_vsi && vsi_seid != 0) { dev_info(&pf->pdev->dev, "vsi seid %d not found\n", vsi_seid); return NULL; }
This condition is not met, although vsi_idx == pf->num_alloc_vsi but vsi_seid == 0 so the rest of code ended by:
ret = i40e_add_veb(veb, vsi);
and vsi pointer points to invalid area (item after the last one from pf->vsi).
As I mentioned the broken floating VEB functionality (where vsi_seid == 0 and uplink_seid == 0) is fixed by the following patch.
Thanks, Ivan
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