From patchwork Thu Jul 2 22:39:06 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Francesco Ruggeri X-Patchwork-Id: 1321972 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=arista.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=arista.com header.i=@arista.com header.a=rsa-sha256 header.s=Arista-A header.b=rl1tlBZH; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 49yY1D3lB7z9sRW for ; Fri, 3 Jul 2020 08:39:12 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726345AbgGBWjH (ORCPT ); Thu, 2 Jul 2020 18:39:07 -0400 Received: from mx.aristanetworks.com ([162.210.129.12]:21615 "EHLO smtp.aristanetworks.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726194AbgGBWjG (ORCPT ); Thu, 2 Jul 2020 18:39:06 -0400 Received: from us180.sjc.aristanetworks.com (us180.sjc.aristanetworks.com [172.25.230.4]) by smtp.aristanetworks.com (Postfix) with ESMTP id 6328640186E; Thu, 2 Jul 2020 15:39:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arista.com; s=Arista-A; t=1593729546; bh=ZVKT4xgQY8MAj9CulrPs/cabyZqtX2jpxJZx1/Wsnmo=; h=Date:To:Subject:From:From; b=rl1tlBZHsyj+T4ch+Pt9WXVyWpeqkSHxK4M1AZj+fn+EK+dxJ4VIA916sX9lRBlBO Jv7CzsqJeG5U08MIY3ZbZoyyJY6tZt1Cu0qOwj8x6LtgDQxb8UUpJ3rNzBVjPBIOT1 Zc6thvjTasuaEmXKSoGk6/jxsRXunWfCu61wYQzdXAEvSSOIsm2qgQGkjfyNyd3R5h Oo68nc18Vo4qtamsk7AzX/SwPvHQFOtsAYPnjX34/mfJJRNWadUo/oSmz/3AMeankf SNzTsIRfx8eYbPwpHjyaf49BnG1Dh+PwbEByI9NOZEAw36OgqOhSFF+qtIrHdWMp+e 40agvPS1SSqvA== Received: by us180.sjc.aristanetworks.com (Postfix, from userid 10189) id 42B6C95C0494; Thu, 2 Jul 2020 15:39:06 -0700 (PDT) Date: Thu, 02 Jul 2020 15:39:06 -0700 To: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, intel-wired-lan@lists.osuosl.org, kuba@kernel.org, davem@davemloft.net, jeffrey.t.kirsher@intel.com, fruggeri@arista.com Subject: [PATCH v2] igb: reinit_locked() should be called with rtnl_lock User-Agent: Heirloom mailx 12.5 7/5/10 Message-Id: <20200702223906.42B6C95C0494@us180.sjc.aristanetworks.com> From: fruggeri@arista.com (Francesco Ruggeri) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org We observed two panics involving races with igb_reset_task. The first panic is caused by this race condition: kworker reboot -f igb_reset_task igb_reinit_locked igb_down napi_synchronize __igb_shutdown igb_clear_interrupt_scheme igb_free_q_vectors igb_free_q_vector adapter->q_vector[v_idx] = NULL; napi_disable Panics trying to access adapter->q_vector[v_idx].napi_state The second panic (a divide error) is caused by this race: kworker reboot -f tx packet igb_reset_task __igb_shutdown rtnl_lock() ... igb_clear_interrupt_scheme igb_free_q_vectors adapter->num_tx_queues = 0 ... rtnl_unlock() rtnl_lock() igb_reinit_locked igb_down igb_up netif_tx_start_all_queues dev_hard_start_xmit igb_xmit_frame igb_tx_queue_mapping Panics on r_idx % adapter->num_tx_queues This commit applies to igb_reset_task the same changes that were applied to ixgbe in commit 2f90b8657ec9 ("ixgbe: this patch adds support for DCB to the kernel and ixgbe driver"), commit 8f4c5c9fb87a ("ixgbe: reinit_locked() should be called with rtnl_lock") and commit 88adce4ea8f9 ("ixgbe: fix possible race in reset subtask"). v2: add fix for second race condition above. Signed-off-by: Francesco Ruggeri Tested-by: Aaron Brown --- drivers/net/ethernet/intel/igb/igb_main.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index 8bb3db2cbd41..6e5861bfb0fa 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -6224,9 +6224,18 @@ static void igb_reset_task(struct work_struct *work) struct igb_adapter *adapter; adapter = container_of(work, struct igb_adapter, reset_task); + rtnl_lock(); + /* If we're already down or resetting, just bail */ + if (test_bit(__IGB_DOWN, &adapter->state) || + test_bit(__IGB_RESETTING, &adapter->state)) { + rtnl_unlock(); + return; + } + igb_dump(adapter); netdev_err(adapter->netdev, "Reset adapter\n"); igb_reinit_locked(adapter); + rtnl_unlock(); } /**