Re: [PATCH] netfilter: Force fake conntrack entry to be at least 8 bytes aligned

From	Pablo Neira Ayuso <pablo@netfilter.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH] netfilter: Force fake conntrack entry to be at least 8 bytes aligned
Date	2017-03-13 13:40 +0100
Message-ID	<tkxqy-uQ-33@gated-at.bofh.it> (permalink)
References	<tjHLj-6sf-5@gated-at.bofh.it> <tjLlT-Fs-1@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Sat, Mar 11, 2017 at 10:12:22AM +0100, Florian Westphal wrote:
> Steven Rostedt (VMware) <rostedt@goodmis.org> wrote:
> > Since the nfct and nfctinfo have been combined, the nf_conn structure
> > must be at least 8 bytes aligned, as the 3 LSB bits are used for the
> > nfctinfo. But there's a fake nf_conn structure to denote untracked
> > connections, which is created by a PER_CPU construct. This does not
> > guarantee that it will be 8 bytes aligned and can break the logic in
> > determining the correct nfctinfo.
> > 
> > I triggered this on a 32bit machine with the following error:
> [..]
> 
> Ugh.  Originally I had planned to also submit followup changes
> to get rid of the untracked objects but that part got delayed.
> 
> > By using DEFINE/DECLARE_PER_CPU_ALIGNED we can enforce at least 8 byte
> > alignment as all cache line sizes are at least 8 bytes or more.
> 
> Thanks for fixing this!
> 
> Acked-by: Florian Westphal <fw@strlen.de>

Applied, thanks.

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[PATCH] netfilter: Force fake conntrack entry to be at least 8  bytes aligned "Steven Rostedt (VMware)" <rostedt@goodmis.org> - 2017-03-11 06:30 +0100
  Re: [PATCH] netfilter: Force fake conntrack entry to be at least 8  bytes aligned Florian Westphal <fw@strlen.de> - 2017-03-11 10:20 +0100
    Re: [PATCH] netfilter: Force fake conntrack entry to be at least 8  bytes aligned Pablo Neira Ayuso <pablo@netfilter.org> - 2017-03-13 13:40 +0100

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