From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752999Ab0IEHty (ORCPT ); Sun, 5 Sep 2010 03:49:54 -0400 Received: from mail-fx0-f46.google.com ([209.85.161.46]:40206 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751433Ab0IEHtw (ORCPT ); Sun, 5 Sep 2010 03:49:52 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:to:cc:in-reply-to:references:content-type:date :message-id:mime-version:x-mailer:content-transfer-encoding; b=Clht4LBW1XQt51ylqcOIhD1jcJ4c3eGkNyJyj9ACg1cJcF4s0aGb3wW12G12TrRBxk j6W3+T2Cc1Ur1ZEYcl3ohC1nISICJerZwUmty2AA0pfOytrQ6DR93eq2VbGWgQ5+N43b +7KV2sXRoyaCOKH7C9dUde5HNufOHuS+mwfXg= Subject: Re: [Bug #16626] Machine hangs with EIP at skb_copy_and_csum_dev From: Eric Dumazet To: Jarek Poplawski Cc: Plamen Petrov , Herbert Xu , "Rafael J. Wysocki" , Kernel Testers List , Maciej Rutecki , "David S. Miller" , Linux Kernel Mailing List , netdev@vger.kernel.org In-Reply-To: <20100904203429.GA4891@del.dom.local> References: <20100904203429.GA4891@del.dom.local> Content-Type: text/plain; charset="UTF-8" Date: Sun, 05 Sep 2010 09:49:43 +0200 Message-ID: <1283672983.3402.38.camel@edumazet-laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le samedi 04 septembre 2010 à 22:34 +0200, Jarek Poplawski a écrit : > Hi again, > > Just had a second look, and unless I miss something... > > Plamen, could you test this patch, too? (Without removing the previous > one.) > > Thanks, > Jarek P. > > -------------------> > > [PATCH] gro: Re-fix different skb headrooms > > The patch: "gro: fix different skb headrooms" in its part: > "2) allocate a minimal skb for head of frag_list" is buggy. The copied > skb has p->data set at the ip header at the moment, and skb_gro_offset > is the length of ip + tcp headers. So, after the change the length of > mac header is skipped. Later skb_set_mac_header() sets it into the > NET_SKB_PAD area (if it's long enough) and ip header is misaligned at > NET_SKB_PAD + NET_IP_ALIGN offset. There is no reason to assume the > original skb was wrongly allocated, so let's copy it as it was. > > bugzilla : https://bugzilla.kernel.org/show_bug.cgi?id=16626 > fixes commit: 3d3be4333fdf6faa080947b331a6a19bce1a4f57 > > Reported-by: Plamen Petrov > Signed-off-by: Jarek Poplawski > CC: Eric Dumazet > --- > > diff --git a/net/core/skbuff.c b/net/core/skbuff.c > index 26396ff..c83b421 100644 > --- a/net/core/skbuff.c > +++ b/net/core/skbuff.c > @@ -2706,7 +2706,7 @@ int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb) > } else if (skb_gro_len(p) != pinfo->gso_size) > return -E2BIG; > > - headroom = NET_SKB_PAD + NET_IP_ALIGN; > + headroom = skb_headroom(p); > nskb = alloc_skb(headroom + skb_gro_offset(p), GFP_ATOMIC); > if (unlikely(!nskb)) > return -ENOMEM; You are right, thanks for reviewing this patch again :) By the way, NET_IP_ALIGN is now 0 on x86, so technically speaking, your patch un-aligns IP header on x86, but thats OK, since other arches might want it being aligned, while x86 doesnt care. Acked-by: Eric Dumazet