On Fri, Aug 28, 2009 at 02:19:19PM -0700, Yu, Fenghua wrote: > >I was seeing "nf_ct_icmpv6: ICMPv6 checksum failed" errors on > >every ICMPv6 packet received. The packets did not pass the > >netfilter checksum verification but they did pass the standard > >verification later and got processed. This happenns with hardware > >checksumming turned off or with adapters that do not checksum > >ICMP packets (e.g. tg3). I tracked the problem down to the ia64 > >version of csum_ipv6_magic() introduced by 007d77d0c5. For some > >arguments, it gives differrent results than the generic version. > > > >The following patch fixes the problem for me. IA64 experts, can > >you please have a look? > > Looks good to me. Do you know the caller function for the failed csum_ipv6_magic()? I saw the problem when csum_ipv6_magic() was called from nf_ip6_checksum(), in the CHECKSUM_NONE branch. The the bug is triggered by having some bits set in the high 32-bits of the register used to pass the sum parameter to csum_ipv6_magic(). For some reason, the csum_sub(skb->csum, skb_checksum(skb, 0, dataoff, 0)) in the CHECKSUM_COMPLETE branch does not seem to trigger this, while the csum_sub(0, skb_checksum(skb, 0, dataoff, 0)) in the CHECKSUM_NONE branch does. I haven't looked at the disassembly to see why, though. -- Jiri Bohac <jbohac@xxxxxxx> SUSE Labs, SUSE CZ -- To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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