From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752508AbaBNQZr (ORCPT ); Fri, 14 Feb 2014 11:25:47 -0500 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:36929 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751551AbaBNQZn (ORCPT ); Fri, 14 Feb 2014 11:25:43 -0500 Date: Fri, 14 Feb 2014 16:24:58 +0000 From: Will Deacon To: Ivaylo Dimitrov Cc: LKML , "linux@arm.linux.org.uk" , "linux-arm-kernel@lists.infradead.org" , Pavel Machek , Sebastian Reichel , Pali =?iso-8859-1?Q?Roh=E1r?= , kvalo@qca.qualcomm.com, linville@tuxdriver.com Subject: Re: [BISECTED] ssh - Received disconnect from x.x.x.x: 2: Bad packet length 3149594624 Message-ID: <20140214162458.GF21986@mudshark.cambridge.arm.com> References: <52FD08D1.3030405@gmail.com> <20140213182105.GN13576@mudshark.cambridge.arm.com> <52FD1243.9040706@gmail.com> <20140213192909.GO13576@mudshark.cambridge.arm.com> <52FE407C.3080002@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <52FE407C.3080002@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 14, 2014 at 04:12:44PM +0000, Ivaylo Dimitrov wrote: > On 13.02.2014 21:29, Will Deacon wrote: > > > > Can you try hacking crypto/memneq.c so that it doesn't use > > CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS please? That would at least point the > > finger at net/mac80211/rx.c or similar. > > > > Well, I am lazy so I hacked net/mac80211/rx.c first: No problem, thanks for having a go. > index c24ca0d..6839c77 100644 > --- a/net/mac80211/rx.c > +++ b/net/mac80211/rx.c > @@ -1963,7 +1963,7 @@ ieee80211_deliver_skb(struct ieee80211_rx_data *rx) > } > } > > -#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS > +//#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS > if (skb) { > /* 'align' will only take the values 0 or 2 here since all > * frames are required to be aligned to 2-byte boundaries > @@ -1987,7 +1987,7 @@ ieee80211_deliver_skb(struct ieee80211_rx_data *rx) > } > } > } > -#endif > +//#endif > > if (skb) { > /* deliver to local stack */ > > > and that seems to fix the problem. > > I am not sure whom I should forward the problem. Well, we probably need a bit more to go on, because I doubt that this code is to blame. More likely, the issue is in the caller. Looking at drivers/net/wireless/ti/wl1251/rx.c:182 /* The actual length doesn't include the target's alignment */ skb->len = desc->length - PLCP_HEADER_LENGTH; fc = (u16 *)skb->data; if ((*fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_BEACON) beacon = 1; wl1251_rx_status(wl, desc, &status, beacon); wl1251_debug(DEBUG_RX, "rx skb 0x%p: %d B %s", skb, skb->len, beacon ? "beacon" : ""); memcpy(IEEE80211_SKB_RXCB(skb), &status, sizeof(status)); ieee80211_rx_ni(wl->hw, skb); I wonder whether that first line (with the comment about alignment) is assuming some behaviour from the mac80211 layer. You could try putting back the UNALIGNED_ACCESS in net/mac80211/rx.c and commenting out the skb->len = desc->length - PLCP_HEADER_LENGTH; line above. Adding the original author (I think) and John Linville, since I'm well out of my depth in this code! Will