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From:   YiFei Zhu <zhuyifei1999@gmail.com>
Date:   Fri, 25 Sep 2020 11:45:05 -0500
Message-ID: <CABqSeASM9B77QrWRbqRF19N9-m-bm779-7a3qEDa8NumjBsorw@mail.gmail.com>
Subject: Re: [PATCH v2 seccomp 3/6] seccomp/cache: Add "emulator" to check if
 filter is arg-dependent
To:     Kees Cook <keescook@chromium.org>
Cc:     Linux Containers <containers@lists.linux-foundation.org>,
        YiFei Zhu <yifeifz2@illinois.edu>, bpf <bpf@vger.kernel.org>,
        kernel list <linux-kernel@vger.kernel.org>,
        Aleksa Sarai <cyphar@cyphar.com>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Andy Lutomirski <luto@amacapital.net>,
        Dimitrios Skarlatos <dskarlat@cs.cmu.edu>,
        Giuseppe Scrivano <gscrivan@redhat.com>,
        Hubertus Franke <frankeh@us.ibm.com>,
        Jack Chen <jianyan2@illinois.edu>,
        Jann Horn <jannh@google.com>,
        Josep Torrellas <torrella@illinois.edu>,
        Tianyin Xu <tyxu@illinois.edu>,
        Tobin Feldman-Fitzthum <tobin@ibm.com>,
        Tycho Andersen <tycho@tycho.pizza>,
        Valentin Rothberg <vrothber@redhat.com>,
        Will Drewry <wad@chromium.org>
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On Thu, Sep 24, 2020 at 10:04 PM YiFei Zhu <zhuyifei1999@gmail.com> wrote:
> > Why do the prepare here instead of during attach? (And note that it
> > should not be written to fail.)
>
> Right.

During attach a spinlock (current->sighand->siglock) is held. Do we
really want to put the emulator in the "atomic section"?

YiFei Zhu