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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 2663DC43333 for ; Wed, 23 Dec 2020 03:06:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D9EE220789 for ; Wed, 23 Dec 2020 03:06:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728483AbgLWDGU (ORCPT ); Tue, 22 Dec 2020 22:06:20 -0500 Received: from mail.kernel.org ([198.145.29.99]:46328 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728477AbgLWCTF (ORCPT ); Tue, 22 Dec 2020 21:19:05 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 86616235F8; Wed, 23 Dec 2020 02:18:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1608689889; bh=dSKaEjABsu3I40sGE2bbbn00CsFmFpI5AvkjtJluISE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PmD8wjzDUip8zTR1eM4JcSMZYuT116WbhYyvw3u4H8dq85ezBbZWpAeZ75F02xQ7i FbJgu33pFv2hsHzPEELCw1xPGlAllykV/7CW7F1CSC387lvD+UyCBIbo+YY+B8mlI0 sMzWhVn0ujiTBoVRvZ7xWYCRjI3FqKh2I/Xxu8ka2T5G3i1E06XTZR8e3lhVPC/pV2 ftPpmkoliH83Y8P187P9D075keaqjCdn60GQJGzizBkTLr6tihnsmHihWD3ChMRu9x S+UhEzuinOFUPatdCilsooDBJqSN/tqK5WhnFAThqqamHwDnZr6nZrwcE7UuFdkOnQ AxY5ReyFl5aOw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Heiner Kallweit , Jakub Kicinski , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 5.10 077/217] r8169: use READ_ONCE in rtl_tx_slots_avail Date: Tue, 22 Dec 2020 21:14:06 -0500 Message-Id: <20201223021626.2790791-77-sashal@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20201223021626.2790791-1-sashal@kernel.org> References: <20201223021626.2790791-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Heiner Kallweit [ Upstream commit 95f3c5458dfa5856bb110e31d156e00d894d0134 ] tp->dirty_tx and tp->cur_tx may be changed by a racing rtl_tx() or rtl8169_start_xmit(). Use READ_ONCE() to annotate the races and ensure that the compiler doesn't use cached values. Signed-off-by: Heiner Kallweit Link: https://lore.kernel.org/r/5676fee3-f6b4-84f2-eba5-c64949a371ad@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/ethernet/realtek/r8169_main.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c index 85d9c3e30c699..67918feed307e 100644 --- a/drivers/net/ethernet/realtek/r8169_main.c +++ b/drivers/net/ethernet/realtek/r8169_main.c @@ -4173,7 +4173,8 @@ static bool rtl8169_tso_csum_v2(struct rtl8169_private *tp, static bool rtl_tx_slots_avail(struct rtl8169_private *tp, unsigned int nr_frags) { - unsigned int slots_avail = tp->dirty_tx + NUM_TX_DESC - tp->cur_tx; + unsigned int slots_avail = READ_ONCE(tp->dirty_tx) + NUM_TX_DESC + - READ_ONCE(tp->cur_tx); /* A skbuff with nr_frags needs nr_frags+1 entries in the tx queue */ return slots_avail > nr_frags; -- 2.27.0