From patchwork Tue Jun 9 13:19:44 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Loftus, Ciara" X-Patchwork-Id: 217902 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, 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 5E2BFC433DF for ; Tue, 9 Jun 2020 13:40:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3A77020774 for ; Tue, 9 Jun 2020 13:40:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730040AbgFINkv (ORCPT ); Tue, 9 Jun 2020 09:40:51 -0400 Received: from mga07.intel.com ([134.134.136.100]:22603 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728888AbgFINku (ORCPT ); Tue, 9 Jun 2020 09:40:50 -0400 IronPort-SDR: 1Q8SS3e2XzwJrZmSCMlDxJM5bl2UJgf+idXHftm1IGKkOUJu44GILzbRKxCx9YmQOiuH1nhLrK MK4V96+mYKKA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Jun 2020 06:40:49 -0700 IronPort-SDR: ECVqyDBtTLe+m4htIZcsDLANRgIAyAN6h2NxYDwRiGAwljoEWYmcT36CjszigxgqFE9SSwqVs0 Cv7OHMzLnxew== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,492,1583222400"; d="scan'208";a="295837449" Received: from silpixa00399839.ir.intel.com (HELO localhost.localdomain) ([10.237.222.8]) by fmsmga004.fm.intel.com with ESMTP; 09 Jun 2020 06:40:48 -0700 From: Ciara Loftus To: intel-wired-lan@lists.osuosl.org Cc: netdev@vger.kernel.org, magnus.karlsson@intel.com, bjorn.topel@intel.com, ciara.loftus@intel.com Subject: [PATCH net 2/3] i40e: protect ring accesses with READ- and WRITE_ONCE Date: Tue, 9 Jun 2020 13:19:44 +0000 Message-Id: <20200609131945.18373-2-ciara.loftus@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200609131945.18373-1-ciara.loftus@intel.com> References: <20200609131945.18373-1-ciara.loftus@intel.com> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org READ_ONCE should be used when reading rings prior to accessing the statistics pointer. Introduce this as well as the corresponding WRITE_ONCE usage when allocating and freeing the rings, to ensure protected access. Signed-off-by: Ciara Loftus --- drivers/net/ethernet/intel/i40e/i40e_main.c | 29 ++++++++++++++------- 1 file changed, 19 insertions(+), 10 deletions(-) diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c index 5d807c8004f8..56ecd6c3f236 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_main.c +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c @@ -439,11 +439,15 @@ static void i40e_get_netdev_stats_struct(struct net_device *netdev, i40e_get_netdev_stats_struct_tx(ring, stats); if (i40e_enabled_xdp_vsi(vsi)) { - ring++; + ring = READ_ONCE(vsi->xdp_rings[i]); + if (!ring) + continue; i40e_get_netdev_stats_struct_tx(ring, stats); } - ring++; + ring = READ_ONCE(vsi->rx_rings[i]); + if (!ring) + continue; do { start = u64_stats_fetch_begin_irq(&ring->syncp); packets = ring->stats.packets; @@ -787,6 +791,8 @@ static void i40e_update_vsi_stats(struct i40e_vsi *vsi) for (q = 0; q < vsi->num_queue_pairs; q++) { /* locate Tx ring */ p = READ_ONCE(vsi->tx_rings[q]); + if (!p) + continue; do { start = u64_stats_fetch_begin_irq(&p->syncp); @@ -800,8 +806,11 @@ static void i40e_update_vsi_stats(struct i40e_vsi *vsi) tx_linearize += p->tx_stats.tx_linearize; tx_force_wb += p->tx_stats.tx_force_wb; - /* Rx queue is part of the same block as Tx queue */ - p = &p[1]; + /* locate Rx ring */ + p = READ_ONCE(vsi->rx_rings[q]); + if (!p) + continue; + do { start = u64_stats_fetch_begin_irq(&p->syncp); packets = p->stats.packets; @@ -10824,10 +10833,10 @@ static void i40e_vsi_clear_rings(struct i40e_vsi *vsi) if (vsi->tx_rings && vsi->tx_rings[0]) { for (i = 0; i < vsi->alloc_queue_pairs; i++) { kfree_rcu(vsi->tx_rings[i], rcu); - vsi->tx_rings[i] = NULL; - vsi->rx_rings[i] = NULL; + WRITE_ONCE(vsi->tx_rings[i], NULL); + WRITE_ONCE(vsi->rx_rings[i], NULL); if (vsi->xdp_rings) - vsi->xdp_rings[i] = NULL; + WRITE_ONCE(vsi->xdp_rings[i], NULL); } } } @@ -10861,7 +10870,7 @@ static int i40e_alloc_rings(struct i40e_vsi *vsi) if (vsi->back->hw_features & I40E_HW_WB_ON_ITR_CAPABLE) ring->flags = I40E_TXR_FLAGS_WB_ON_ITR; ring->itr_setting = pf->tx_itr_default; - vsi->tx_rings[i] = ring++; + WRITE_ONCE(vsi->tx_rings[i], ring++); if (!i40e_enabled_xdp_vsi(vsi)) goto setup_rx; @@ -10879,7 +10888,7 @@ static int i40e_alloc_rings(struct i40e_vsi *vsi) ring->flags = I40E_TXR_FLAGS_WB_ON_ITR; set_ring_xdp(ring); ring->itr_setting = pf->tx_itr_default; - vsi->xdp_rings[i] = ring++; + WRITE_ONCE(vsi->xdp_rings[i], ring++); setup_rx: ring->queue_index = i; @@ -10892,7 +10901,7 @@ static int i40e_alloc_rings(struct i40e_vsi *vsi) ring->size = 0; ring->dcb_tc = 0; ring->itr_setting = pf->rx_itr_default; - vsi->rx_rings[i] = ring; + WRITE_ONCE(vsi->rx_rings[i], ring); } return 0;