Messages in this thread | | | Date | Wed, 08 Sep 2010 07:57:31 +0300 | From | Plamen Petrov <> | Subject | Re: [Bug #16626] Machine hangs with EIP at skb_copy_and_csum_dev |
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На 05.9.2010 г. 10:49, Eric Dumazet написа: > 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<pvp-lsts@fs.uni-ruse.bg> >> Signed-off-by: Jarek Poplawski<jarkao2@gmail.com> >> CC: Eric Dumazet<eric.dumazet@gmail.com> >> --- >> >> 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<eric.dumazet@gmail.com> > > >
Well, now that I'm back at work, I'm glad to report that I tested both variants of the patch, and as Eric points out - it works both ways.
So, which ever fits you guys better.
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