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authorBjörn Töpel <bjorn.topel@intel.com>2019-02-14 14:03:02 +0100
committerJeff Kirsher <jeffrey.t.kirsher@intel.com>2019-02-21 11:07:49 -0800
commit59eb2a884f5380011179acc4662fc2cc2d850454 (patch)
treee2d1a2c7fd0d379dfe6bf09a44e1ab3e7e1f648e /drivers/net/ethernet/intel/i40e
parentixgbe: fix potential RX buffer starvation for AF_XDP (diff)
downloadlinux-dev-59eb2a884f5380011179acc4662fc2cc2d850454.tar.xz
linux-dev-59eb2a884f5380011179acc4662fc2cc2d850454.zip
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: d9314c474d4f ("i40e: add support for XDP_REDIRECT") Fixes: 123cecd427b6 ("i40e: added queue pair disable/enable functions") Reported-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Diffstat (limited to 'drivers/net/ethernet/intel/i40e')
-rw-r--r--drivers/net/ethernet/intel/i40e/i40e_main.c14
-rw-r--r--drivers/net/ethernet/intel/i40e/i40e_txrx.c4
2 files changed, 15 insertions, 3 deletions
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 3a0990de81c1..e4ff531db14a 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -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]);
}
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index a7e14e98889f..6c97667d20ef 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -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))