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=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 27534C433E7 for ; Mon, 19 Oct 2020 18:43:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BA676223AE for ; Mon, 19 Oct 2020 18:43:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603133003; bh=b2QJk34z+3ifQSCj/0BnigPQn31Jz5SJrS4DHmzD/vk=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=kh7S5cNJ/r/uWBj1lOJ66bBRlkjKnK+viBNE7Nw+IrPkTCZJ7KGzGbub5LuVYB6IW rOK3eYrTDUJflSmuVDPOTcZ3iQRLvAT7Zyd2FJO2IqByYF1N0aX69aMoIyEbNU5bYy 4VJf6GhawWBzv67aWqfDoiGD9Xm2RX/G547pHQhI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730878AbgJSSnW (ORCPT ); Mon, 19 Oct 2020 14:43:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:59526 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730710AbgJSSnW (ORCPT ); Mon, 19 Oct 2020 14:43:22 -0400 Received: from kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com (c-67-180-217-166.hsd1.ca.comcast.net [67.180.217.166]) (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 895C0222E9; Mon, 19 Oct 2020 18:43:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603133002; bh=b2QJk34z+3ifQSCj/0BnigPQn31Jz5SJrS4DHmzD/vk=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=OAyygtJSOw+Yi89YFc+Vm0nHE25PALgzP9u5e0/nmkuS+ux1ygPQDB0+ZXkeixSWP Veh8reTviWp6TvT2wvjeBbVXuALTYFsUBwIXmTGenH/5U0OnHRZx/b2fPugHCqqIzw N5MgRga6PmDZB0iaBMFysPi1rrWma/ugYLEYG7gk= Date: Mon, 19 Oct 2020 11:43:19 -0700 From: Jakub Kicinski To: Jia-Ju Bai Cc: kvalo@codeaurora.org, davem@davemloft.net, vaibhavgupta40@gmail.com, christophe.jaillet@wanadoo.fr, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] rtl8180: avoid accessing the data mapped to streaming DMA Message-ID: <20201019114319.1b699ffa@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> In-Reply-To: <20201019025420.3789-1-baijiaju1990@gmail.com> References: <20201019025420.3789-1-baijiaju1990@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 19 Oct 2020 10:54:20 +0800 Jia-Ju Bai wrote: > + if (info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ) { > + if (info->flags & IEEE80211_TX_CTL_FIRST_FRAGMENT) > + priv->seqno += 0x10; > + hdr->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG); > + hdr->seq_ctrl |= cpu_to_le16(priv->seqno); > + } > + > mapping = dma_map_single(&priv->pdev->dev, skb->data, skb->len, > DMA_TO_DEVICE); > > @@ -534,13 +541,6 @@ static void rtl8180_tx(struct ieee80211_hw *dev, > > spin_lock_irqsave(&priv->lock, flags); > > - if (info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ) { > - if (info->flags & IEEE80211_TX_CTL_FIRST_FRAGMENT) > - priv->seqno += 0x10; You're taking the priv->seqno access and modification from under priv->lock. Is that okay?