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From:   Jann Horn <jannh@google.com>
Date:   Thu, 24 Sep 2020 21:18:32 +0200
Message-ID: <CAG48ez3s9u+5_Bd94CP97aqBBKzno1o2obpJPSdMnsHHkOd0qg@mail.gmail.com>
Subject: Re: [PATCH v1 0/6] seccomp: Implement constant action bitmaps
To:     Andrea Arcangeli <aarcange@redhat.com>
Cc:     Kees Cook <keescook@chromium.org>,
        YiFei Zhu <yifeifz2@illinois.edu>,
        Christian Brauner <christian.brauner@ubuntu.com>,
        Tycho Andersen <tycho@tycho.pizza>,
        Andy Lutomirski <luto@amacapital.net>,
        Will Drewry <wad@chromium.org>,
        Giuseppe Scrivano <gscrivan@redhat.com>,
        Tobin Feldman-Fitzthum <tobin@ibm.com>,
        Dimitrios Skarlatos <dskarlat@cs.cmu.edu>,
        Valentin Rothberg <vrothber@redhat.com>,
        Hubertus Franke <frankeh@us.ibm.com>,
        Jack Chen <jianyan2@illinois.edu>,
        Josep Torrellas <torrella@illinois.edu>,
        Tianyin Xu <tyxu@illinois.edu>, bpf <bpf@vger.kernel.org>,
        Linux Containers <containers@lists.linux-foundation.org>,
        Linux API <linux-api@vger.kernel.org>,
        kernel list <linux-kernel@vger.kernel.org>
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On Thu, Sep 24, 2020 at 8:57 PM Andrea Arcangeli <aarcange@redhat.com> wrote:
>
> Hello,
>
> I'm posting this only for the record, feel free to ignore.
>
> On Wed, Sep 23, 2020 at 04:29:17PM -0700, Kees Cook wrote:
> > rfc: https://lore.kernel.org/lkml/20200616074934.1600036-1-keescook@chromium.org/
> > alternative: https://lore.kernel.org/containers/cover.1600661418.git.yifeifz2@illinois.edu/
> > v1:
> > - rebase to for-next/seccomp
> > - finish X86_X32 support for both pinning and bitmaps
>
> It's pretty clear the O(1) seccomp filter bitmap was first was
> proposed by your RFC in June (albeit it was located in the wrong place
> and is still in the wrong place in v1).
>
> > - replace TLB magic with Jann's emulator
>     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>
> That's a pretty fundamental change in v1 compared to your the
> non-competing TLB magic technique you used in the RFC last June.
>
> The bitmap isn't the clever part of the patch, the bitmap can be
> reviewed in seconds, the difficult part to implement and to review is
> how you fill the bitmap and in that respect there's absolutely nothing
> in common in between the "rfc:" and the "alternative" link.
>
> In June your bitmap-filling engine was this:
>
> https://lore.kernel.org/lkml/20200616074934.1600036-5-keescook@chromium.org/
>
> Then on Sep 21 YiFei Zhu posted his new innovative BPF emulation
> innovation that obsoleted your TLB magic of June:
>
> https://lists.linuxfoundation.org/pipermail/containers/2020-September/042153.html
>
> And on Sep 23 instead of collaborating and helping YiFei Zhu to
> improve his BPF emulator, you posted the same technique that looks
> remarkably similar without giving YiFei Zhu any attribution and you
> instead attribute the whole idea to Jann Horn:
>
> https://lkml.kernel.org/r/20200923232923.3142503-5-keescook@chromium.org

You're missing that I did suggest the BPF emulation approach (with
code very similar to Kees' current code) back in June:
https://lore.kernel.org/lkml/CAG48ez1p=dR_2ikKq=xVxkoGg0fYpTBpkhJSv1w-6BG=76PAvw@mail.gmail.com/