From patchwork Fri Jan 17 21:47:20 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Saleem, Shiraz" X-Patchwork-Id: 11339893 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B6B4114B7 for ; Fri, 17 Jan 2020 21:55:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 946332192A for ; Fri, 17 Jan 2020 21:55:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726587AbgAQVzv (ORCPT ); Fri, 17 Jan 2020 16:55:51 -0500 Received: from mga07.intel.com ([134.134.136.100]:62725 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729340AbgAQVzu (ORCPT ); Fri, 17 Jan 2020 16:55:50 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Jan 2020 13:48:49 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,331,1574150400"; d="scan'208";a="214627116" Received: from atorres1-mobl1.gar.corp.intel.com (HELO ssaleem-MOBL.amr.corp.intel.com) ([10.255.88.87]) by orsmga007.jf.intel.com with ESMTP; 17 Jan 2020 13:48:49 -0800 From: Shiraz Saleem To: dledford@redhat.com, jgg@ziepe.ca Cc: linux-rdma@vger.kernel.org, "Shiraz Saleem" Subject: [PATCH rdma-nxt] i40iw: Do an RCU lookup in i40iw_add_ipv4_addr Date: Fri, 17 Jan 2020 15:47:20 -0600 Message-Id: <20200117214720.1960-1-shiraz.saleem@intel.com> X-Mailer: git-send-email 2.21.0 MIME-Version: 1.0 Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org From: "Shiraz Saleem" 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 since there are no netdev object updates in this function. Fixes: 8e06af711bf2 ("i40iw: add main, hdr, status") Signed-off-by: Shiraz Saleem --- drivers/infiniband/hw/i40iw/i40iw_main.c | 16 +++++----------- 1 file changed, 5 insertions(+), 11 deletions(-) diff --git a/drivers/infiniband/hw/i40iw/i40iw_main.c b/drivers/infiniband/hw/i40iw/i40iw_main.c index 2386143..d7a1219 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)) { 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(); } /**