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=-9.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 66E7FC43381 for ; Thu, 14 Feb 2019 13:03:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3207F21900 for ; Thu, 14 Feb 2019 13:03:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="n+wTNx+q" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391453AbfBNNDZ (ORCPT ); Thu, 14 Feb 2019 08:03:25 -0500 Received: from mail-pg1-f193.google.com ([209.85.215.193]:40580 "EHLO mail-pg1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726299AbfBNNDY (ORCPT ); Thu, 14 Feb 2019 08:03:24 -0500 Received: by mail-pg1-f193.google.com with SMTP id z10so3048532pgp.7 for ; Thu, 14 Feb 2019 05:03:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=lDy1DCHBXZRItP1ANKUY8Bib2ggcM7hedgaiPMyrEnk=; b=n+wTNx+qa/z93rfgCqzwVRbB4MO36EdIylTPxmd7Yg3wCa8mSR9U4oTDtiEIYpRXF+ zLZDkXA1bg2/t54JAV0Qzm6PKeI4+ps3uQ2LkJih9GSg+Q7fXK7kgrnRA1+34ncyVOyy bUf/3ZeAC5wTO4HLmNHe7JRmWJu2FpBaRQfpIouYTstZZTk45D5CHjMJ980W8Q9wtncl TB5g4lP9OJ0sZd/CBGQldVB3UNJN+RScOwjrWfaDs/7bdUg6qvvjZfLYQXh98QWyAq50 h1w/DrN6AaQHqYwcR6KzVEL+9Lv+NIoltNMUV2VfjsKmNaLetxvKkudnPK6vn8wPWRmh ayYA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=lDy1DCHBXZRItP1ANKUY8Bib2ggcM7hedgaiPMyrEnk=; b=FgqBjfkMDXEwuRCfaoCLIpiPKasp5ti9q6yG2gUW7I5HNG9uchdkkCT6HaJX82aQrZ Zxk/XHDqIMqKDSeO38BMiscuaKmdT27/ZVKvHqMypfwUOWMd/0Q35WijTh72XfWgm6R0 v5QF2TilFUtVK5iA1T65yXyyUNrJ+k8aNavya/9mErwBnDSxa3pHNJPxRDDW18/X75Hv W8cvES/jyF+u8uABmNS+l4PqSS4A7j4XJUYSnkazSz1J4kD0sa4JhFd4ing/yFWP7n6e 4hAvYLlxvj90LxY3aVrbIH8Puw0VrO6CL9UddgdCvBPjUIGkI908we0psVZRlQOhW+mB aXag== X-Gm-Message-State: AHQUAubmpxe9lFu7dlvKcCgG1wW/fS3uryE7WPtBYrEExrmQW9qXqfmi 3kxo3csWNndn9kmZm66a270pr/mv+KXk8g== X-Google-Smtp-Source: AHgI3IZaMTb8XJsquYeu8AlJdGeBfl/wgW0y5ymloXk7eKIxZjqaUue9x0kMEgcaCCTQBpqE3A+36A== X-Received: by 2002:a62:ee13:: with SMTP id e19mr3926345pfi.224.1550149403547; Thu, 14 Feb 2019 05:03:23 -0800 (PST) Received: from btopel-mobl.ger.intel.com ([192.55.54.45]) by smtp.gmail.com with ESMTPSA id o85sm5735428pfi.105.2019.02.14.05.03.19 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 14 Feb 2019 05:03:22 -0800 (PST) From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= To: intel-wired-lan@lists.osuosl.org Cc: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= , magnus.karlsson@intel.com, magnus.karlsson@gmail.com, brouer@redhat.com, netdev@vger.kernel.org, maciej.fijalkowski@intel.com Subject: [PATCH net] i40e: fix XDP_REDIRECT/XDP xmit ring cleanup race Date: Thu, 14 Feb 2019 14:03:02 +0100 Message-Id: <20190214130302.29434-1-bjorn.topel@gmail.com> X-Mailer: git-send-email 2.19.1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Björn Töpel When the driver clears the XDP xmit ring due to re-configuration or teardown, in-progress ndo_xdp_xmit must be taken into consideration. The ndo_xdp_xmit function is typically called from a napi context that the driver does not control. Therefore, we must be careful not to clear the XDP ring, while the call is on-going. This patch adds a synchronize_rcu() to wait for napi(s) (preempt-disable regions and softirqs), prior clearing the queue. Further, the __I40E_CONFIG_BUSY flag is checked in the ndo_xdp_xmit implementation to avoid touching the XDP xmit queue during re-configuration. Fixes: d9314c474d4f ("i40e: add support for XDP_REDIRECT") Fixes: 123cecd427b6 ("i40e: added queue pair disable/enable functions") Reported-by: Maciej Fijalkowski Signed-off-by: Björn Töpel --- drivers/net/ethernet/intel/i40e/i40e_main.c | 14 ++++++++++++-- drivers/net/ethernet/intel/i40e/i40e_txrx.c | 4 +++- 2 files changed, 15 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c index f52e2c46e6a7..6a54a1e2f4ae 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_main.c +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c @@ -6725,8 +6725,13 @@ void i40e_down(struct i40e_vsi *vsi) for (i = 0; i < vsi->num_queue_pairs; i++) { i40e_clean_tx_ring(vsi->tx_rings[i]); - if (i40e_enabled_xdp_vsi(vsi)) + if (i40e_enabled_xdp_vsi(vsi)) { + /* Make sure that in-progress ndo_xdp_xmit + * calls are completed. + */ + synchronize_rcu(); i40e_clean_tx_ring(vsi->xdp_rings[i]); + } i40e_clean_rx_ring(vsi->rx_rings[i]); } @@ -11955,8 +11960,13 @@ static void i40e_queue_pair_reset_stats(struct i40e_vsi *vsi, int queue_pair) static void i40e_queue_pair_clean_rings(struct i40e_vsi *vsi, int queue_pair) { i40e_clean_tx_ring(vsi->tx_rings[queue_pair]); - if (i40e_enabled_xdp_vsi(vsi)) + if (i40e_enabled_xdp_vsi(vsi)) { + /* Make sure that in-progress ndo_xdp_xmit calls are + * completed. + */ + synchronize_rcu(); i40e_clean_tx_ring(vsi->xdp_rings[queue_pair]); + } i40e_clean_rx_ring(vsi->rx_rings[queue_pair]); } diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c index a7e14e98889f..6c97667d20ef 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c @@ -3709,6 +3709,7 @@ int i40e_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames, struct i40e_netdev_priv *np = netdev_priv(dev); unsigned int queue_index = smp_processor_id(); struct i40e_vsi *vsi = np->vsi; + struct i40e_pf *pf = vsi->back; struct i40e_ring *xdp_ring; int drops = 0; int i; @@ -3716,7 +3717,8 @@ int i40e_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames, if (test_bit(__I40E_VSI_DOWN, vsi->state)) return -ENETDOWN; - if (!i40e_enabled_xdp_vsi(vsi) || queue_index >= vsi->num_queue_pairs) + if (!i40e_enabled_xdp_vsi(vsi) || queue_index >= vsi->num_queue_pairs || + test_bit(__I40E_CONFIG_BUSY, pf->state)) return -ENXIO; if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) -- 2.19.1