From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 63660C35247 for ; Tue, 4 Feb 2020 22:39:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2CD382087E for ; Tue, 4 Feb 2020 22:39:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727500AbgBDWjk (ORCPT ); Tue, 4 Feb 2020 17:39:40 -0500 Received: from mga04.intel.com ([192.55.52.120]:60114 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727468AbgBDWjk (ORCPT ); Tue, 4 Feb 2020 17:39:40 -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 fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 04 Feb 2020 14:39:40 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,403,1574150400"; d="scan'208";a="219904035" Received: from ssaleem-mobl.amr.corp.intel.com ([10.254.10.239]) by orsmga007.jf.intel.com with ESMTP; 04 Feb 2020 14:39:39 -0800 From: Shiraz Saleem To: dledford@redhat.com, jgg@ziepe.ca Cc: linux-rdma@vger.kernel.org, Shiraz Saleem Subject: [PATCH v1 rdma-next] i40iw: Do an RCU lookup in i40iw_add_ipv4_addr Date: Tue, 4 Feb 2020 16:38:40 -0600 Message-Id: <20200204223840.2151-1-shiraz.saleem@intel.com> X-Mailer: git-send-email 2.21.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org 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. Fixes: 8e06af711bf2 ("i40iw: add main, hdr, status") Signed-off-by: Shiraz Saleem --- v0-->v1: Annotate dev->flags with READ_ONCE 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(); } /** -- 1.8.3.1