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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 84115C00140 for ; Thu, 18 Aug 2022 13:22:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244983AbiHRNWZ (ORCPT ); Thu, 18 Aug 2022 09:22:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47792 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244978AbiHRNWY (ORCPT ); Thu, 18 Aug 2022 09:22:24 -0400 Received: from mail-ej1-x632.google.com (mail-ej1-x632.google.com [IPv6:2a00:1450:4864:20::632]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 51558B02BE for ; Thu, 18 Aug 2022 06:22:23 -0700 (PDT) Received: by mail-ej1-x632.google.com with SMTP id fy5so3236912ejc.3 for ; Thu, 18 Aug 2022 06:22:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:content-language:in-reply-to:mime-version :user-agent:date:message-id:from:references:cc:to:subject:from:to:cc; bh=M6twNLDdiAyqijRujWv+jTZ/HkYbrPlBRR42YrvjkjY=; b=g/Y7R8gntw8Hr1VOzIKddVDRq7c0csGngBk+2mFJNQOFR5vdrU9Iov9GaBWVkSjZaU xlBrNgb/v3iH93zJjeopGoWpZmWJxltMpcrWmHI5/jVjZmOWfd3+fV3WqWBkQwYXn1r3 mbTUJQ/DRtWpWd6c4r9R5xJGgNwHZK+wVNRHC/SQ6dKEqHCixlCRb/Kjm9HgDr2pvt0a UxTj2KvftEinpclnghSxYPa/OrAyGCwwHGQOlt++A1monPzyyMkzRL0He1Mroyc7um4b tQMdHiFzW2ogAkHiCZMRFz+Zt+y6swnFwAIDbFuSkm1kbuBVeU8LowyvF65kLECTCI1V +3tg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:content-language:in-reply-to:mime-version :user-agent:date:message-id:from:references:cc:to:subject :x-gm-message-state:from:to:cc; bh=M6twNLDdiAyqijRujWv+jTZ/HkYbrPlBRR42YrvjkjY=; b=OkFwJliqJt6eyvgmmR9nvVENrCUZa4VB5jYFkV4uqXBwzmq/Pk7VPTdT1KJ9qdBKnO b5JmC+CYs3x3j9bxRiVMRWTbWJ07qzxhp6QOv3VUARdKhpoOKUK6jKvk7wrr0/Bxxixt B4+l/WwsR+yxhOU5ttTzGsQl0/d8TkAGfOkP3DcS+GkPAL40Zp3HfB2PDMRgxBKIoGwi rh0msyZzb9/sjRcTTGJrge0rXL8ej3FW591slam6c20cXaQhugGxfWFyEEjL5PkgVw2F eTW/Z9xgoQDA7GhXHfKC5qaM8N8OYYSGFZQxmDjKemdDBoKdQaXYMviJoqojEYSvGfNt xpyw== X-Gm-Message-State: ACgBeo1Zrwv9+a3VEvz2bXtNSD2VztIln8hTH+SvrwDQS/RLrW+BqUsn Azqe/pVbwRGM//hsmSwH3vw= X-Google-Smtp-Source: AA6agR6TJCRyPHrVTHIVHom/5b7ETg1N+HX3gnNp1USgtRSIKB/QG49+f8rzqj1ecYW37cyLNzCU6g== X-Received: by 2002:a17:907:2cd1:b0:730:65c9:4c18 with SMTP id hg17-20020a1709072cd100b0073065c94c18mr1910878ejc.324.1660828941806; Thu, 18 Aug 2022 06:22:21 -0700 (PDT) Received: from [192.168.1.122] (cpc159313-cmbg20-2-0-cust161.5-4.cable.virginm.net. [82.0.78.162]) by smtp.gmail.com with ESMTPSA id w23-20020aa7cb57000000b0043ba0cf5dbasm1180064edt.2.2022.08.18.06.22.20 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 18 Aug 2022 06:22:21 -0700 (PDT) Subject: Re: [PATCH v2 net 15/17] net: Fix a data-race around gro_normal_batch. To: Kuniyuki Iwashima , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: Kuniyuki Iwashima , netdev@vger.kernel.org, Edward Cree References: <20220818035227.81567-1-kuniyu@amazon.com> <20220818035227.81567-16-kuniyu@amazon.com> From: Edward Cree Message-ID: Date: Thu, 18 Aug 2022 14:22:20 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: <20220818035227.81567-16-kuniyu@amazon.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 18/08/2022 04:52, Kuniyuki Iwashima wrote: > While reading gro_normal_batch, it can be changed concurrently. > Thus, we need to add READ_ONCE() to its reader. > > Fixes: 323ebb61e32b ("net: use listified RX for handling GRO_NORMAL skbs") > Signed-off-by: Kuniyuki Iwashima > --- > CC: Edward Cree Acked-by: Edward Cree > --- > include/net/gro.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/net/gro.h b/include/net/gro.h > index 867656b0739c..24003dea8fa4 100644 > --- a/include/net/gro.h > +++ b/include/net/gro.h > @@ -439,7 +439,7 @@ static inline void gro_normal_one(struct napi_struct *napi, struct sk_buff *skb, > { > list_add_tail(&skb->list, &napi->rx_list); > napi->rx_count += segs; > - if (napi->rx_count >= gro_normal_batch) > + if (napi->rx_count >= READ_ONCE(gro_normal_batch)) > gro_normal_list(napi); > } > >