From 9a4b24108d92ffaa886e37923088bd806b988948 Mon Sep 17 00:00:00 2001 From: Shiraz Saleem Date: Tue, 4 Feb 2020 16:38:40 -0600 Subject: [PATCH] i40iw: Do an RCU lookup in i40iw_add_ipv4_addr The in_dev_for_each_ifa_rtnl() iterator in i40iw_add_ipv4_addr requires that the rtnl lock be held. But the rtnl_trylock/unlock scheme in this function does not guarantee it. Replace the rtnl locking with an RCU lookup using in_dev_for_each_ifa_rcu() Fixes: 8e06af711bf2 ("i40iw: add main, hdr, status") Link: https://lore.kernel.org/r/20200204223840.2151-1-shiraz.saleem@intel.com Signed-off-by: Shiraz Saleem Signed-off-by: Jason Gunthorpe --- drivers/infiniband/hw/i40iw/i40iw_main.c | 18 ++++++------------ 1 file changed, 6 insertions(+), 12 deletions(-) diff --git a/drivers/infiniband/hw/i40iw/i40iw_main.c b/drivers/infiniband/hw/i40iw/i40iw_main.c index 2386143..84e1b52 100644 --- a/drivers/infiniband/hw/i40iw/i40iw_main.c +++ b/drivers/infiniband/hw/i40iw/i40iw_main.c @@ -1212,22 +1212,19 @@ static void i40iw_add_ipv4_addr(struct i40iw_device *iwdev) { struct net_device *dev; struct in_device *idev; - bool got_lock = true; u32 ip_addr; - if (!rtnl_trylock()) - got_lock = false; - - for_each_netdev(&init_net, dev) { + rcu_read_lock(); + for_each_netdev_rcu(&init_net, dev) { if ((((rdma_vlan_dev_vlan_id(dev) < 0xFFFF) && (rdma_vlan_dev_real_dev(dev) == iwdev->netdev)) || - (dev == iwdev->netdev)) && (dev->flags & IFF_UP)) { + (dev == iwdev->netdev)) && (READ_ONCE(dev->flags) & IFF_UP)) { const struct in_ifaddr *ifa; - idev = in_dev_get(dev); + idev = __in_dev_get_rcu(dev); if (!idev) continue; - in_dev_for_each_ifa_rtnl(ifa, idev) { + in_dev_for_each_ifa_rcu(ifa, idev) { i40iw_debug(&iwdev->sc_dev, I40IW_DEBUG_CM, "IP=%pI4, vlan_id=%d, MAC=%pM\n", &ifa->ifa_address, rdma_vlan_dev_vlan_id(dev), dev->dev_addr); @@ -1239,12 +1236,9 @@ static void i40iw_add_ipv4_addr(struct i40iw_device *iwdev) true, I40IW_ARP_ADD); } - - in_dev_put(idev); } } - if (got_lock) - rtnl_unlock(); + rcu_read_unlock(); } /** -- 2.7.4