net/ixgbe: Fix concurrency issues between config flow and XSK (c0fdccfd) · Commits · 戴 / test

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

drivers/net/ethernet/intel/ixgbe/ixgbe_main.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -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);

drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c

+6 −2

Original line number	Diff line number	Diff line
		@@ -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);

Admin message