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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 6EA01C433E0 for ; Thu, 18 Jun 2020 02:47:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3FB7920776 for ; Thu, 18 Jun 2020 02:47:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592448478; bh=8cYg6YWaQ92yyXv7/1wtOlTaxEGIiAIY8Tv1LNlbrn8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=DsrYbT/wbMc8yiWlS2V+2xsvyvAWJEDNF0B1bXGSunQgbPGZfiKVUcYx3bXykFGRk +lBG/KajDuAESjI57HmoOUuKIQ0xXnlLH3TaZToFsLLp3NecEGHEys1X0h1R4j7q8B X9iRWjVm1JJ9WlED4yOtae6p98zUZ2Cxsojl7HDk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728137AbgFRCr5 (ORCPT ); Wed, 17 Jun 2020 22:47:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:37210 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728426AbgFRBKM (ORCPT ); Wed, 17 Jun 2020 21:10:12 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3FEAB21D90; Thu, 18 Jun 2020 01:10:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592442612; bh=8cYg6YWaQ92yyXv7/1wtOlTaxEGIiAIY8Tv1LNlbrn8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RJ3w3U6QqyAvhzqVcQgb4prhQqLwHiuYMVKqfir2OFf7LQHMDQi06jV7048n+D6U5 UF8zPqLYkAt/sF14VATYvtJ/0zuQ7wp9iuewYG4ecNwjY1Sq3uapL/aI72K1uFkCnT lgsgVvpGW6r/8jAjCl2ILS/pKgDbHsp707JpNjaw= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Ahmed S. Darwish" , kernel test robot , Sebastian Andrzej Siewior , "David S . Miller" , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 5.7 093/388] net: mdiobus: Disable preemption upon u64_stats update Date: Wed, 17 Jun 2020 21:03:10 -0400 Message-Id: <20200618010805.600873-93-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200618010805.600873-1-sashal@kernel.org> References: <20200618010805.600873-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 7a4eb3f2cb74..a1a4dee2a033 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(); } /** -- 2.25.1