Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753796AbaJ1MK7 (ORCPT ); Tue, 28 Oct 2014 08:10:59 -0400 Received: from mail.karo-electronics.de ([81.173.242.67]:64630 "EHLO mail.karo-electronics.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752091AbaJ1MK5 convert rfc822-to-8bit (ORCPT ); Tue, 28 Oct 2014 08:10:57 -0400 Date: Tue, 28 Oct 2014 13:10:51 +0100 From: Lothar =?UTF-8?B?V2HDn21hbm4=?= To: David Laight Cc: "netdev@vger.kernel.org" , "David S. Miller" , Russell King , Frank Li , "Fabio Estevam" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" Subject: Re: [PATCHv2 6/6] net: fec: fix regression on i.MX28 introduced by rx_copybreak support Message-ID: <20141028131051.6d214ae0@ipc1.ka-ro> In-Reply-To: <063D6719AE5E284EB5DD2968C1650D6D1C9E04DB@AcuExch.aculab.com> References: <1414494104-27943-1-git-send-email-LW@KARO-electronics.de> <1414494104-27943-7-git-send-email-LW@KARO-electronics.de> <063D6719AE5E284EB5DD2968C1650D6D1C9E04DB@AcuExch.aculab.com> Organization: Ka-Ro electronics GmbH X-Mailer: Claws Mail 3.8.1 (GTK+ 2.24.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, David Laight wrote: > From: Lothar Waßmann > > commit 1b7bde6d659d ("net: fec: implement rx_copybreak to improve rx performance") > > introduced a regression for i.MX28. The swap_buffer() function doing > > the endian conversion of the received data on i.MX28 may access memory > > beyond the actual packet size in the DMA buffer. fec_enet_copybreak() > > does not copy those bytes, so that the last bytes of a packet may be > > filled with invalid data after swapping. > > This will likely lead to checksum errors on received packets. > > E.g. when trying to mount an NFS rootfs: > > UDP: bad checksum. From 192.168.1.225:111 to 192.168.100.73:44662 ulen 36 > > > > Do the byte swapping and copying to the new skb in one go if > > necessary. > > > > Signed-off-by: Lothar Wamann > > --- > > drivers/net/ethernet/freescale/fec_main.c | 25 +++++++++++++++++++++---- > > 1 file changed, 21 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c > > index 404fb9d..b92324c 100644 > > --- a/drivers/net/ethernet/freescale/fec_main.c > > +++ b/drivers/net/ethernet/freescale/fec_main.c > > @@ -339,6 +339,18 @@ static void *swap_buffer(void *bufaddr, int len) > > return bufaddr; > > } > > > > +static void *swap_buffer2(void *dst_buf, void *src_buf, int len) > > +{ > > + int i; > > + unsigned int *src = src_buf; > > + unsigned int *dst = dst_buf; > > + > > + for (i = 0; i < len; i += 4, src++, dst++) > > + swab32s(src); > > + > > + return dst_buf; > > +} > > + > > Actually that is completely f*cked.... > Yeah, noticed that shortly after sending out. :( One change too many... Lothar Waßmann -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/