[PATCH net v4 1/4] octeon_ep: fix race conditions in ndo_get_stats64

[Shinas Rasheed <srasheed@marvell.com>]

ndo_get_stats64() can race with ndo_stop(), which frees input and
output queue resources. Check if netdev is running before accessing
per queue resources.

Fixes: 6a610a46bad1 ("octeon_ep: add support for ndo ops")
Signed-off-by: Shinas Rasheed <srasheed@marvell.com>
---
V4:
  - Check if netdev is running, as decision for accessing resources
    rather than availing lock implementations, in ndo_get_stats64()

V3: https://lore.kernel.org/all/20241218115111.2407958-2-srasheed@marvell.com/
  - No changes 

V2: https://lore.kernel.org/all/20241216075842.2394606-2-srasheed@marvell.com/
  - Changed sync mechanism to fix race conditions from using an atomic
    set_bit ops to a much simpler synchronize_net()

V1: https://lore.kernel.org/all/20241203072130.2316913-2-srasheed@marvell.com/

 drivers/net/ethernet/marvell/octeon_ep/octep_main.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/marvell/octeon_ep/octep_main.c b/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
index 549436efc204..a452ee3b9a98 100644
--- a/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
+++ b/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
@@ -995,16 +995,14 @@ static void octep_get_stats64(struct net_device *netdev,
 	struct octep_device *oct = netdev_priv(netdev);
 	int q;
 
-	if (netif_running(netdev))
-		octep_ctrl_net_get_if_stats(oct,
-					    OCTEP_CTRL_NET_INVALID_VFID,
-					    &oct->iface_rx_stats,
-					    &oct->iface_tx_stats);
-
 	tx_packets = 0;
 	tx_bytes = 0;
 	rx_packets = 0;
 	rx_bytes = 0;
+
+	if (!netif_running(netdev))
+		return;
+
 	for (q = 0; q < oct->num_oqs; q++) {
 		struct octep_iq *iq = oct->iq[q];
 		struct octep_oq *oq = oct->oq[q];
-- 
2.25.1