From patchwork Tue Jun 23 19:51:29 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 223578 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=-10.0 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, 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 5CFAAC433E1 for ; Tue, 23 Jun 2020 20:04:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2DC062082F for ; Tue, 23 Jun 2020 20:04:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592942682; bh=oWN/GHMJ1I/nfSKHPsEfpd0EtGfTOxA4OujpXXhXAN8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Xe15vC+7ZbHpxsGu8jmIx1SORKv0/6Vzf3XRx7zRiauaDg+sAp358MQrP9NYOcd5E 2qZtH7DZdFtV78TkLq0zXgvWePK4v3ls+uP+b4R2k4QO11CvssESEA5Auy4IO0Ig4+ SgSLdTLHdJszQY6ErYNx/YA6Ip/0kqawDevmsvpQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388240AbgFWUEl (ORCPT ); Tue, 23 Jun 2020 16:04:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:43338 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388236AbgFWUEi (ORCPT ); Tue, 23 Jun 2020 16:04:38 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C0E502080C; Tue, 23 Jun 2020 20:04:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592942678; bh=oWN/GHMJ1I/nfSKHPsEfpd0EtGfTOxA4OujpXXhXAN8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BDL82bVEr8NNXB3x0M8rdHRzC9Ms9KhLaIf23vG8t3YjaEA+CONZSZaliGmL/jWYx 4AoRiBxB5YX1J9M8CSEiaXMg8hR9VWDVwA8eu+g2IkUNnvReAPvY56aREA7XikV69o FBZI9v7YBq4Gk9ANQNRxs1q9NX5E/AA2H+zMqHpY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, kernel test robot , "Ahmed S. Darwish" , Sebastian Andrzej Siewior , "David S. Miller" , Sasha Levin Subject: [PATCH 5.7 092/477] net: mdiobus: Disable preemption upon u64_stats update Date: Tue, 23 Jun 2020 21:51:29 +0200 Message-Id: <20200623195411.952647146@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200623195407.572062007@linuxfoundation.org> References: <20200623195407.572062007@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Ahmed S. Darwish [ Upstream commit c7e261d81783387a0502878cd229327e7c54322e ] The u64_stats mechanism uses sequence counters to protect against 64-bit values tearing on 32-bit architectures. Updating u64_stats is thus a sequence counter write side critical section where preemption must be disabled. For mdiobus_stats_acct(), disable preemption upon the u64_stats update. It is called from process context through mdiobus_read() and mdiobus_write(). Reported-by: kernel test robot Signed-off-by: Ahmed S. Darwish Reviewed-by: Sebastian Andrzej Siewior Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/phy/mdio_bus.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c index 7a4eb3f2cb743..a1a4dee2a033a 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -757,6 +757,7 @@ EXPORT_SYMBOL(mdiobus_scan); static void mdiobus_stats_acct(struct mdio_bus_stats *stats, bool op, int ret) { + preempt_disable(); u64_stats_update_begin(&stats->syncp); u64_stats_inc(&stats->transfers); @@ -771,6 +772,7 @@ static void mdiobus_stats_acct(struct mdio_bus_stats *stats, bool op, int ret) u64_stats_inc(&stats->writes); out: u64_stats_update_end(&stats->syncp); + preempt_enable(); } /**