From: Maxim Mikityanskiy <maximmi@xxxxxxxxxxxx> [ Upstream commit c0fdccfd226a1424683d3000d9e08384391210a2 ] 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@xxxxxxxxxxxx> Signed-off-by: Björn Töpel <bjorn.topel@xxxxxxxxx> Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx> Link: https://lore.kernel.org/bpf/20191217162023.16011-5-maximmi@xxxxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 7 ++++++- drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c | 8 ++++++-- 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 1a7203fede12..c6404abf2dd1 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c @@ -10248,7 +10248,12 @@ 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); -- 2.20.1
