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authorMaxim Mikityanskiy <maximmi@mellanox.com>2019-12-17 16:20:47 +0000
committerDaniel Borkmann <daniel@iogearbox.net>2019-12-19 16:20:49 +0100
commitc0fdccfd226a1424683d3000d9e08384391210a2 (patch)
treebc5d84b8543985f1b7c03f1ff1a2c6edc0306cdd
parentb3873a5be757b44d51af542a50a6f2a3b6f95284 (diff)
net/ixgbe: Fix concurrency issues between config flow and XSK
Use synchronize_rcu to wait until the XSK wakeup function finishes before destroying the resources it uses: 1. ixgbe_down already calls synchronize_rcu after setting __IXGBE_DOWN. 2. After switching the XDP program, call synchronize_rcu to let ixgbe_xsk_wakeup exit before the XDP program is freed. 3. Changing the number of channels brings the interface down. 4. Disabling UMEM sets __IXGBE_TX_DISABLED before closing hardware resources and resetting xsk_umem. Check that bit in ixgbe_xsk_wakeup to avoid using the XDP ring when it's already destroyed. synchronize_rcu is called from ixgbe_txrx_ring_disable. Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com> Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191217162023.16011-5-maximmi@mellanox.com
-rw-r--r--drivers/net/ethernet/intel/ixgbe/ixgbe_main.c7
-rw-r--r--drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c8
2 files changed, 12 insertions, 3 deletions
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 25c097cd8100..82a30b597cf9 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -10261,7 +10261,12 @@ static int ixgbe_xdp_setup(struct net_device *dev, struct bpf_prog *prog)
/* If transitioning XDP modes reconfigure rings */
if (need_reset) {
- int err = ixgbe_setup_tc(dev, adapter->hw_tcs);
+ int err;
+
+ if (!prog)
+ /* Wait until ndo_xsk_wakeup completes. */
+ synchronize_rcu();
+ err = ixgbe_setup_tc(dev, adapter->hw_tcs);
if (err) {
rcu_assign_pointer(adapter->xdp_prog, old_prog);
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c
index d6feaacfbf89..b43be9f14105 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c
@@ -709,10 +709,14 @@ int ixgbe_xsk_wakeup(struct net_device *dev, u32 qid, u32 flags)
if (qid >= adapter->num_xdp_queues)
return -ENXIO;
- if (!adapter->xdp_ring[qid]->xsk_umem)
+ ring = adapter->xdp_ring[qid];
+
+ if (test_bit(__IXGBE_TX_DISABLED, &ring->state))
+ return -ENETDOWN;
+
+ if (!ring->xsk_umem)
return -ENXIO;
- ring = adapter->xdp_ring[qid];
if (!napi_if_scheduled_mark_missed(&ring->q_vector->napi)) {
u64 eics = BIT_ULL(ring->q_vector->v_idx);