From b3873a5be757b44d51af542a50a6f2a3b6f95284 Mon Sep 17 00:00:00 2001 From: Maxim Mikityanskiy Date: Tue, 17 Dec 2019 16:20:45 +0000 Subject: net/i40e: Fix concurrency issues between config flow and XSK MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Use synchronize_rcu to wait until the XSK wakeup function finishes before destroying the resources it uses: 1. i40e_down already calls synchronize_rcu. On i40e_down either __I40E_VSI_DOWN or __I40E_CONFIG_BUSY is set. Check the latter in i40e_xsk_wakeup (the former is already checked there). 2. After switching the XDP program, call synchronize_rcu to let i40e_xsk_wakeup exit before the XDP program is freed. 3. Changing the number of channels brings the interface down (see i40e_prep_for_reset and i40e_pf_quiesce_all_vsi). 4. Disabling UMEM sets __I40E_CONFIG_BUSY, too. Signed-off-by: Maxim Mikityanskiy Signed-off-by: Björn Töpel Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20191217162023.16011-4-maximmi@mellanox.com --- drivers/net/ethernet/intel/i40e/i40e_xsk.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/net/ethernet/intel/i40e/i40e_xsk.c') diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c index d07e1a890428..f73cd917c44f 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c +++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c @@ -787,8 +787,12 @@ int i40e_xsk_wakeup(struct net_device *dev, u32 queue_id, u32 flags) { struct i40e_netdev_priv *np = netdev_priv(dev); struct i40e_vsi *vsi = np->vsi; + struct i40e_pf *pf = vsi->back; struct i40e_ring *ring; + if (test_bit(__I40E_CONFIG_BUSY, pf->state)) + return -ENETDOWN; + if (test_bit(__I40E_VSI_DOWN, vsi->state)) return -ENETDOWN; -- cgit