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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 7C85DC46464 for ; Thu, 9 Aug 2018 17:52:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2780721E97 for ; Thu, 9 Aug 2018 17:52:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2780721E97 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=perches.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728305AbeHIUSB (ORCPT ); Thu, 9 Aug 2018 16:18:01 -0400 Received: from smtprelay0135.hostedemail.com ([216.40.44.135]:39986 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727704AbeHIURt (ORCPT ); Thu, 9 Aug 2018 16:17:49 -0400 Received: from filter.hostedemail.com (clb03-v110.bra.tucows.net [216.40.38.60]) by smtprelay04.hostedemail.com (Postfix) with ESMTP id 6C7F9180A8130; Thu, 9 Aug 2018 17:51:52 +0000 (UTC) X-Session-Marker: 6A6F6540706572636865732E636F6D X-HE-Tag: doll91_103118c0d7d4c X-Filterd-Recvd-Size: 3857 Received: from XPS-9350.home (unknown [47.151.153.53]) (Authenticated sender: joe@perches.com) by omf07.hostedemail.com (Postfix) with ESMTPA; Thu, 9 Aug 2018 17:51:51 +0000 (UTC) Message-ID: Subject: Re: [PATCH 3/5] staging: rtl8188eu: use is_multicast_ether_addr in rtw_xmit.c From: Joe Perches To: Michael Straube , gregkh@linuxfoundation.org Cc: devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, Alexander Duyck , "David S. Miller" Date: Thu, 09 Aug 2018 10:51:49 -0700 In-Reply-To: References: <20180809170131.29279-1-straube.linux@gmail.com> <20180809170131.29279-3-straube.linux@gmail.com> Content-Type: text/plain; charset="ISO-8859-1" X-Mailer: Evolution 3.28.1-2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2018-08-09 at 19:42 +0200, Michael Straube wrote: > On 8/9/18 7:13 PM, Joe Perches wrote: > > On Thu, 2018-08-09 at 19:01 +0200, Michael Straube wrote: > > > Use is_multicast_ether_addr instead of custom IS_MCAST in > > > core/rtw_xmit.c. > > > > Have you verified that all accesses are __aligned(2) ? > > > > If so, please state that in the patch description. > > > > > diff --git a/drivers/staging/rtl8188eu/core/rtw_xmit.c b/drivers/staging/rtl8188eu/core/rtw_xmit.c > > > > [] > > > @@ -460,10 +460,10 @@ static s32 update_attrib(struct adapter *padapter, struct sk_buff *pkt, struct p > > > if ((pattrib->ether_type == ETH_P_ARP) || (pattrib->ether_type == ETH_P_PAE) || (pattrib->dhcp_pkt == 1)) > > > rtw_lps_ctrl_wk_cmd(padapter, LPS_CTRL_SPECIAL_PACKET, 1); > > > > > > - bmcast = IS_MCAST(pattrib->ra); > > > + mcast = is_multicast_ether_addr(pattrib->ra); > > > > i.e.: is pattrib->ra __aligned(2) ? > > > > etc... > > > > Hi Joe, > > I looked at the function comment for is_multicast_ether_addr in etherdevice.h. > There is not mentioned that __aligned(2) is required. If it is, I will check. > > So, is it required although it's not mentioned for is_multicast_ether_addr? Well, it wasn't required initially, but commit d54385ce68cd18ab002b46f61246ad197cec92de Author: Alexander Duyck Date: Thu Apr 30 14:53:54 2015 -0700 etherdev: Process is_multicast_ether_addr at same size as other operations This change makes it so that we process the address in is_multicast_ether_addr at the same size as the other calls. This allows us to avoid duplicate reads when used with other calls such as is_zero_ether_addr or eth_addr_copy. In addition I have added a 64 bit version of the function so in eth_type_trans we can process the destination address as a 64 bit value throughout. Signed-off-by: Alexander Duyck Signed-off-by: David S. Miller changed it without adding a note in the kernel-doc. So this is likely appropriate to avoid unaligned access traps: --- include/linux/etherdevice.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/include/linux/etherdevice.h b/include/linux/etherdevice.h index 572e11bb8696..0f7086b4836a 100644 --- a/include/linux/etherdevice.h +++ b/include/linux/etherdevice.h @@ -115,6 +115,8 @@ static inline bool is_zero_ether_addr(const u8 *addr) * * Return true if the address is a multicast address. * By definition the broadcast address is also a multicast address. + * + * Please note: addr must be aligned to u16. */ static inline bool is_multicast_ether_addr(const u8 *addr) {