From patchwork Mon May 7 14:08:09 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jia-Ju Bai X-Patchwork-Id: 909765 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=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="PueRyCpA"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 40fkxP5KVYz9s37 for ; Tue, 8 May 2018 00:08:41 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752641AbeEGOI1 (ORCPT ); Mon, 7 May 2018 10:08:27 -0400 Received: from mail-io0-f194.google.com ([209.85.223.194]:46916 "EHLO mail-io0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751943AbeEGOIX (ORCPT ); Mon, 7 May 2018 10:08:23 -0400 Received: by mail-io0-f194.google.com with SMTP id f21-v6so33828643iob.13; Mon, 07 May 2018 07:08:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=tKG5OxEMr9m7/S8t/A/keOs914xzDY2zD+i3LGuKNVM=; b=PueRyCpAT09a+PRx2JvwcIbLg+u8tr/V2N7khamIG3nPdR12yhFHcfNC5M/XzQYOIU onorvxB5IKV7yWjKB3XifTumil9ZOn6lzkF4+6quIpLxy38LZT0kfFtxx5oT2FpqApzD KCH5KvbOmBlRQ+z2ggC6xnQLgJlj0czpC5Ub7gwcKfQ8AlXpIqzXIb/9yUPbd7Bq5eBL a6DlCHh+yiF4wToFJ+okfdW/ipDNdwqpAJoNIsptShtCFAFSLcoINz6eMrIv1Mv+wjx2 /23NlHLQZdm+coxCpR2s8WHwQUbS7yZ28/qnPtefuRnD8zdXLo45yTpB80UlXChzO0XA 1Ptg== 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; bh=tKG5OxEMr9m7/S8t/A/keOs914xzDY2zD+i3LGuKNVM=; b=ExrbaL27jXc2x+gfcMaWPpO9K4UF1vB+g2ZZTunmTOrJGrLRpkJwMUXy0flP/tS3Lk EtODyu/AeYbQDuNJ26sSpux5g/7e8gNUGbNUbpf6ydPi+8ohW5QYC40c4qBixWd4pLY7 LQ1em9Bi+rjgVXOFjomJrCa62/KxVBhkreqoFwGEX2dMXIYHbwSQGnX1Rb6q1JVbmbKt K6RWQh0DcFWJYpFNCCHZ1duKnhOH75nXITQYwicjEjVdj+vZvUWPUAUv8RCyxT2bwUsM m8z5wjASRuv140Z7w3C2/96APRuzDf5S2z7hyCiDzzo3EclZD2p4jEdviab/jssIBzJv lAbg== X-Gm-Message-State: ALQs6tBgo82AjuEMAegTQA+E+PYAvBYV1ctW0SQkbtHIRtFDsyUHgp/T rL9jN4Moo9o8NQ5HpMNVXYA= X-Google-Smtp-Source: AB8JxZrg+93ndJTI6w3hw/apCVYENb8fNN0H1/JSkLorLhuem9lHGEoZ/hRVnJP9ScZUIqHtu3BnnQ== X-Received: by 2002:a63:7250:: with SMTP id c16-v6mr29706808pgn.385.1525702103206; Mon, 07 May 2018 07:08:23 -0700 (PDT) Received: from oslab.tsinghua.edu.cn ([2402:f000:1:4413:18bf:4b0b:7f52:49b]) by smtp.gmail.com with ESMTPSA id x186-v6sm36498489pgb.6.2018.05.07.07.08.21 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 07 May 2018 07:08:22 -0700 (PDT) From: Jia-Ju Bai To: davem@davemloft.net, fthain@telegraphics.com.au, joe@perches.com Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Jia-Ju Bai Subject: [PATCH] net: 8390: Fix possible data races in __ei_get_stats Date: Mon, 7 May 2018 22:08:09 +0800 Message-Id: <20180507140809.28847-1-baijiaju1990@gmail.com> X-Mailer: git-send-email 2.17.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The write operations to "dev->stats" are protected by the spinlock on line 862-864, but the read operations to this data on line 858 and 867 are not protected by the spinlock. Thus, there may exist data races for "dev->stats". To fix the data races, the read operations to "dev->stats" are protected by the spinlock, and a local variable is used for return. Signed-off-by: Jia-Ju Bai --- drivers/net/ethernet/8390/lib8390.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/8390/lib8390.c b/drivers/net/ethernet/8390/lib8390.c index c9c55c9eab9f..198952247d30 100644 --- a/drivers/net/ethernet/8390/lib8390.c +++ b/drivers/net/ethernet/8390/lib8390.c @@ -852,19 +852,25 @@ static struct net_device_stats *__ei_get_stats(struct net_device *dev) unsigned long ioaddr = dev->base_addr; struct ei_device *ei_local = netdev_priv(dev); unsigned long flags; + struct net_device_stats *stats; + + spin_lock_irqsave(&ei_local->page_lock, flags); /* If the card is stopped, just return the present stats. */ - if (!netif_running(dev)) - return &dev->stats; + if (!netif_running(dev)) { + stats = &dev->stats; + spin_unlock_irqrestore(&ei_local->page_lock, flags); + return stats; + } - spin_lock_irqsave(&ei_local->page_lock, flags); /* Read the counter registers, assuming we are in page 0. */ dev->stats.rx_frame_errors += ei_inb_p(ioaddr + EN0_COUNTER0); dev->stats.rx_crc_errors += ei_inb_p(ioaddr + EN0_COUNTER1); dev->stats.rx_missed_errors += ei_inb_p(ioaddr + EN0_COUNTER2); + stats = &dev->stats; spin_unlock_irqrestore(&ei_local->page_lock, flags); - return &dev->stats; + return stats; } /*