[PATCH 5.10 112/142] i40e: acquire VSI pointer only after VF is initialized

Greg Kroah-Hartman
2021-02-02T14:04:16Z

From: Stefan Assmann <sassmann@kpanic.de>

[ Upstream commit 67a3c6b3cc40bb217c3ff947a55053151a00fea0 ]

This change simplifies the VF initialization check and also minimizes
the delay between acquiring the VSI pointer and using it. As known by
the commit being fixed, there is a risk of the VSI pointer getting
changed. Therefore minimize the delay between getting and using the
pointer.

Fixes: 9889707b06ac ("i40e: Fix crash caused by stress setting of VF MAC addresses")
Signed-off-by: Stefan Assmann <sassmann@kpanic.de>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Konrad Jankowski <konrad0.jankowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
index 61968e9174dab..2872c4dc77f07 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
@@ -4046,20 +4046,16 @@ int i40e_ndo_set_vf_mac(struct net_device *netdev, int vf_id, u8 *mac)
goto error_param;

vf = &pf->vf[vf_id];
- vsi = pf->vsi[vf->lan_vsi_idx];

/* When the VF is resetting wait until it is done.
* It can take up to 200 milliseconds,
* but wait for up to 300 milliseconds to be safe.
- * If the VF is indeed in reset, the vsi pointer has
- * to show on the newly loaded vsi under pf->vsi[id].
+ * Acquire the VSI pointer only after the VF has been
+ * properly initialized.
*/
for (i = 0; i < 15; i++) {
- if (test_bit(I40E_VF_STATE_INIT, &vf->vf_states)) {
- if (i > 0)
- vsi = pf->vsi[vf->lan_vsi_idx];
+ if (test_bit(I40E_VF_STATE_INIT, &vf->vf_states))
break;
- }
msleep(20);
}
if (!test_bit(I40E_VF_STATE_INIT, &vf->vf_states)) {
@@ -4068,6 +4064,7 @@ int i40e_ndo_set_vf_mac(struct net_device *netdev, int vf_id, u8 *mac)
ret = -EAGAIN;
goto error_param;
}
+ vsi = pf->vsi[vf->lan_vsi_idx];

if (is_multicast_ether_addr(mac)) {
dev_err(&pf->pdev->dev,
--
2.27.0