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References: <20191212181422.31033-1-linux@dominikbrodowski.net>
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From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Sun, 15 Dec 2019 11:50:46 -0800
Message-ID: <CAHk-=wjfD_b6fS+tYp68gVFw9qB7FgTGa-coNHZeho0B6t3nMg@mail.gmail.com>
Subject: Re: [GIT PULL] remove ksys_mount() and ksys_dup()
To:     Dominik Brodowski <linux@dominikbrodowski.net>
Cc:     Alexander Viro <viro@zeniv.linux.org.uk>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Rafael J . Wysocki" <rafael@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Ingo Molnar <mingo@kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Thu, Dec 12, 2019 at 10:14 AM Dominik Brodowski
<linux@dominikbrodowski.net> wrote:
>
>       the fifth parameter (void *data)
> is either NULL or refers to a full page (only occurence
> in init/do_mounts.c::do_mount_root()).

We probably should aim for the fifth parameter being a "buf, len" pair
at some point.

Then the system call interface still needs to copy the whole page and
pass in PAGE_SIZE as the length, but it would be a better model than
the magical fixed "it's always one page". And the kernel init sequence
wouldn't need that silly temporary page any more.

                 Linus