From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S933484AbbEMIXL (ORCPT <rfc822;w@1wt.eu>);
	Wed, 13 May 2015 04:23:11 -0400
Received: from userp1040.oracle.com ([156.151.31.81]:30172 "EHLO
	userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S932438AbbEMIXH (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Wed, 13 May 2015 04:23:07 -0400
Date: Wed, 13 May 2015 11:22:54 +0300
From: Dan Carpenter <dan.carpenter@oracle.com>
To: Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
Cc: devel@driverdev.osuosl.org, gregkh@linuxfoundation.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 03/33] staging: rtl8192e: Mark unaligned memcpy()
Message-ID: <20150513082254.GQ14154@mwanda>
References: <1431206361-13736-1-git-send-email-mateusz.kulikowski@gmail.com>
 <1431206361-13736-4-git-send-email-mateusz.kulikowski@gmail.com>
 <20150511082646.GI14154@mwanda>
 <55525BCD.5030901@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <55525BCD.5030901@gmail.com>
User-Agent: Mutt/1.5.21 (2010-09-15)
X-Source-IP: aserv0022.oracle.com [141.146.126.234]
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Tue, May 12, 2015 at 10:00:13PM +0200, Mateusz Kulikowski wrote:
> On 11.05.2015 10:26, Dan Carpenter wrote:
> (...)
> >>  				 */
> >>  				skb_pull(sub_skb, SNAP_SIZE);
> >> -				memcpy(skb_push(sub_skb, ETH_ALEN), prxb->src, ETH_ALEN);
> >> -				memcpy(skb_push(sub_skb, ETH_ALEN), prxb->dst, ETH_ALEN);
> >> +				memcpy(skb_push(sub_skb, ETH_ALEN), prxb->src,
> >> +				       ETH_ALEN); /* Must be unaligned */
> > 
> > 
> > Which part isn't aligned?  I think they both are.
> > 
> struct rtllib_rxb *prxb = prxbIndicateArray[j];
> 
> struct rtllib_rxb {
> 	u8 nr_subframes;
> 	struct sk_buff *subframes[MAX_SUBFRAME_COUNT == 64];
> 	u8 dst[ETH_ALEN]; // here
> 	u8 src[ETH_ALEN]; // here
> } __packed;
> 
> Either I forgot alignment / packing rules or this fields are never aligned "by design".

You must have forgotten something...  Everything after the pointer is
going to be aligned sizeof(void *).

regards,
dan carpenter