Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 59eb2a88 authored by Björn Töpel's avatar Björn Töpel Committed by Jeff Kirsher
Browse files

i40e: fix XDP_REDIRECT/XDP xmit ring cleanup race 



When the driver clears the XDP xmit ring due to re-configuration or
teardown, in-progress ndo_xdp_xmit must be taken into consideration.

The ndo_xdp_xmit function is typically called from a NAPI context that
the driver does not control. Therefore, we must be careful not to
clear the XDP ring, while the call is on-going. This patch adds a
synchronize_rcu() to wait for napi(s) (preempt-disable regions and
softirqs), prior clearing the queue. Further, the __I40E_CONFIG_BUSY
flag is checked in the ndo_xdp_xmit implementation to avoid touching
the XDP xmit queue during re-configuration.

Fixes: d9314c47 ("i40e: add support for XDP_REDIRECT")
Fixes: 123cecd4 ("i40e: added queue pair disable/enable functions")
Reported-by: default avatarMaciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: default avatarBjörn Töpel <bjorn.topel@intel.com>
Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
parent 4a9b32f3

drivers/net/ethernet/intel/i40e/i40e_main.c

+12 −2
Original line number Diff line number Diff line
@@ -6728,8 +6728,13 @@ void i40e_down(struct i40e_vsi *vsi) 


	for (i = 0; i < vsi->num_queue_pairs; i++) {

		i40e_clean_tx_ring(vsi->tx_rings[i]);

		if (i40e_enabled_xdp_vsi(vsi))

		if (i40e_enabled_xdp_vsi(vsi)) {

			/* Make sure that in-progress ndo_xdp_xmit

			 * calls are completed.

			 */

			synchronize_rcu();

			i40e_clean_tx_ring(vsi->xdp_rings[i]);

		}

		i40e_clean_rx_ring(vsi->rx_rings[i]);

	}
@@ -11966,8 +11971,13 @@ static void i40e_queue_pair_reset_stats(struct i40e_vsi *vsi, int queue_pair) 
static void i40e_queue_pair_clean_rings(struct i40e_vsi *vsi, int queue_pair)

{

	i40e_clean_tx_ring(vsi->tx_rings[queue_pair]);

	if (i40e_enabled_xdp_vsi(vsi))

	if (i40e_enabled_xdp_vsi(vsi)) {

		/* Make sure that in-progress ndo_xdp_xmit calls are

		 * completed.

		 */

		synchronize_rcu();

		i40e_clean_tx_ring(vsi->xdp_rings[queue_pair]);

	}

	i40e_clean_rx_ring(vsi->rx_rings[queue_pair]);

}

drivers/net/ethernet/intel/i40e/i40e_txrx.c

+3 −1
Original line number Diff line number Diff line
@@ -3709,6 +3709,7 @@ int i40e_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames, 
	struct i40e_netdev_priv *np = netdev_priv(dev);

	unsigned int queue_index = smp_processor_id();

	struct i40e_vsi *vsi = np->vsi;

	struct i40e_pf *pf = vsi->back;

	struct i40e_ring *xdp_ring;

	int drops = 0;

	int i;
@@ -3716,7 +3717,8 @@ int i40e_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames, 
	if (test_bit(__I40E_VSI_DOWN, vsi->state))

		return -ENETDOWN;



	if (!i40e_enabled_xdp_vsi(vsi) || queue_index >= vsi->num_queue_pairs)

	if (!i40e_enabled_xdp_vsi(vsi) || queue_index >= vsi->num_queue_pairs ||

	    test_bit(__I40E_CONFIG_BUSY, pf->state))

		return -ENXIO;



	if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))