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From:   Andy Lutomirski <luto@kernel.org>
Date:   Sat, 21 Nov 2020 20:01:10 -0800
Message-ID: <CALCETrVtwmS0707L5RbWvJpyw-+xtT73xph59DJC2TGa-Hhw1Q@mail.gmail.com>
Subject: Re: [PATCH v7 3/7] kernel: Implement selective syscall userspace redirection
To:     Kees Cook <keescook@chromium.org>
Cc:     Gabriel Krisman Bertazi <krisman@collabora.com>,
        Andrew Lutomirski <luto@kernel.org>,
        Rich Felker <dalias@libc.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Christian Brauner <christian.brauner@ubuntu.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Matthew Wilcox <willy@infradead.org>,
        Shuah Khan <shuah@kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Linux API <linux-api@vger.kernel.org>,
        "open list:KERNEL SELFTEST FRAMEWORK" 
        <linux-kselftest@vger.kernel.org>, X86 ML <x86@kernel.org>,
        Paul Gofman <gofmanp@gmail.com>, kernel@collabora.com
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On Fri, Nov 20, 2020 at 4:18 PM Kees Cook <keescook@chromium.org> wrote:
>
> On Thu, Nov 19, 2020 at 12:43:05PM -0500, Gabriel Krisman Bertazi wrote:
> > The existing interface could be extended with a flags field as part of
> > the opcode passed in argument 2, which is currently reserved, and then
> > return a FD, just like seccomp(2) does.  So it is not like the current
> > patches couldn't be extended in the future if needed, unless I'm
> > mistaken.
>
> Yes, I'd prefer this series go in as-is, and if there is a need for
> extending the API, arg2 can have more values added.

I agree.


>
> --
> Kees Cook