From 59eb2a884f5380011179acc4662fc2cc2d850454 Mon Sep 17 00:00:00 2001 From: Björn Töpel Date: Thu, 14 Feb 2019 14:03:02 +0100 Subject: i40e: fix XDP_REDIRECT/XDP xmit ring cleanup race MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Björn Töpel Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/i40e/i40e_main.c | 14 ++++++++++++-- drivers/net/ethernet/intel/i40e/i40e_txrx.c | 4 +++- 2 files changed, 15 insertions(+), 3 deletions(-) (limited to 'drivers/net/ethernet') 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)) -- cgit v1.2.3-59-g8ed1b