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=-14.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 56B15C63697 for ; Thu, 19 Nov 2020 01:54:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EBDF6246B0 for ; Thu, 19 Nov 2020 01:54:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="XBYO4bbo" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727755AbgKSByT (ORCPT ); Wed, 18 Nov 2020 20:54:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60558 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726468AbgKSByS (ORCPT ); Wed, 18 Nov 2020 20:54:18 -0500 Received: from mail-pf1-x443.google.com (mail-pf1-x443.google.com [IPv6:2607:f8b0:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 53A7BC0613D4; Wed, 18 Nov 2020 17:54:18 -0800 (PST) Received: by mail-pf1-x443.google.com with SMTP id g7so2928619pfc.2; Wed, 18 Nov 2020 17:54:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-transfer-encoding:content-language; bh=oilqbm0PbyF3KMvGCOoKWnR48rcsD2eNT+QPWjMgMFw=; b=XBYO4bbob8cQz4HlqKLE1CpP4bo91AyKwEtYi6lLaUPpXPb/l43xjXhmlhsfhdcWtu 5dAK3cD7tFm1HvXrltDWAvY/qfCVXbzCCH/pq8cfwQsbnJsEi+L6fvP1aEuEjWjbjvmA RChjXZK5uTYhshAWglI19xWnnaSQ3O1lojiCx/l0feXQ7FzdhI/lH0OhJnqug9VuFavk iVWyEqBHCh12Pi6YwJJ+uHPhyKHK27yi8g5HKGmVTbXrIVrzU8qHWtvWhPvZ/EmYVwWc A4g8VUUCvhQisNyLY1jjaN9BUR+r/hVCPfVOCHGtv19arFF1XFfcEdD3WHK8GxWOX9/Z MZ9w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=oilqbm0PbyF3KMvGCOoKWnR48rcsD2eNT+QPWjMgMFw=; b=Re3uJFzzBz092FIm5QGklIWsqKD26DhRKKmX1m701hSx095oU/2RH1ktOXYvo37BzG GBOJLht3p+P5V9jTQuo+bTsqC66G5q1nK3jlYagCnPdYzeVT08A7xrqtNGUgaZtx9U9y C9qmc82gID7t/7XmtJAEwmUl2WoizgrFjHqwJMNuUXdxL2BSSJ+xX3yFmwlux/iZ4WM6 T2H8kfAmzr8/QeIuMlyEkG+SzfFt9cVoWKb8c03fUc1dn7HTT6pbDI7cFrWeq1I2sZeu 2tzrKc9oK42995QzJD6ReRVMwtii1Oxrj4uFvFtes0bxJ/ozD6ZlA+fd2Nsw0v75Gn+p IK4g== X-Gm-Message-State: AOAM530z9YDbqZkYMOptncNOr3V5LctCKYnsR3EKDGlbsbLP3Loov/nW p9zHOby1O0yKe+CEWfm3FIDW2Kkhqd2sUA== X-Google-Smtp-Source: ABdhPJyODx/iAkOp7RFSPXqLNcVJygh8K6z2gu97gOXFOyZNWaZZYMZ+k/FvdeND6jmU05sD+kwIxA== X-Received: by 2002:a63:4558:: with SMTP id u24mr10751984pgk.376.1605750857559; Wed, 18 Nov 2020 17:54:17 -0800 (PST) Received: from [10.165.0.22] ([45.56.153.149]) by smtp.gmail.com with ESMTPSA id u5sm24066564pgj.28.2020.11.18.17.54.14 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 18 Nov 2020 17:54:16 -0800 (PST) Subject: Re: [PATCH v2 1/4] rtlwifi: rtl8188ee: avoid accessing the data mapped to streaming DMA To: Larry Finger , pkshih@realtek.com, kvalo@codeaurora.org, davem@davemloft.net, kuba@kernel.org Cc: linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org References: <20201118015314.4979-1-baijiaju1990@gmail.com> From: Jia-Ju Bai Message-ID: <9a4a11cf-6505-3434-85fa-262e3e16bc47@gmail.com> Date: Thu, 19 Nov 2020 09:54:14 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thanks for the advice. I have added the description of the changes and resent the patches. Best wishes, Jia-Ju Bai On 2020/11/19 1:20, Larry Finger wrote: > On 11/17/20 7:53 PM, Jia-Ju Bai wrote: >> In rtl88ee_tx_fill_cmddesc(), skb->data is mapped to streaming DMA on >> line 677: >>    dma_addr_t mapping = dma_map_single(..., skb->data, ...); >> >> On line 680, skb->data is assigned to hdr after cast: >>    struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)(skb->data); >> >> Then hdr->frame_control is accessed on line 681: >>    __le16 fc = hdr->frame_control; >> >> This DMA access may cause data inconsistency between CPU and hardwre. >> >> To fix this bug, hdr->frame_control is accessed before the DMA mapping. >> >> Signed-off-by: Jia-Ju Bai >> --- >>   drivers/net/wireless/realtek/rtlwifi/rtl8188ee/trx.c | 6 +++--- >>   1 file changed, 3 insertions(+), 3 deletions(-) > > What changed between v1 and v2? > > As outlined in Documentation/process/submitting-patches.rst, you > should add a '---' marker and descrive what was changed. I usually > summarize the changes, but it is also possible to provide a diffstat > of the changes as the above file shows. >