From: David Herrmann <dh.herrmann@gmail.com>
To: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Cc: linux-mm <linux-mm@kvack.org>, Ryan Lortie <desrt@desrt.ca>,
Kay Sievers <kay@vrfy.org>, Johannes Weiner <hannes@cmpxchg.org>,
Hugh Dickins <hughd@google.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
DRI <dri-devel@lists.freedesktop.org>,
Daniel Mack <zonque@gmail.com>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Karol Lewandowski <k.lewandowsk@samsung.com>,
Lennart Poettering <lennart@poettering.net>,
Greg Kroah-Hartman <greg@kroah.com>, Tejun Heo <tj@kernel.org>,
"Michael Kerrisk \(man-pages\)" <mtk.manpages@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Alexander Viro <viro@zeniv.linux.org.uk>
Subject: Re: [PATCH 0/6] File Sealing & memfd_create()
Date: Thu, 20 Mar 2014 16:12:54 +0100 [thread overview]
Message-ID: <CANq1E4Ro8bsgp1QS_Qf9KKBAMZH+joMW5DmfyZ4OBJuTxdXCZA@mail.gmail.com> (raw)
In-Reply-To: <20140320144127.1d411f26@alan.etchedpixels.co.uk>
Hi
On Thu, Mar 20, 2014 at 3:41 PM, One Thousand Gnomes
<gnomes@lxorguk.ukuu.org.uk> wrote:
> I think you want two things at minimum
>
> owner to seal
> root can always override
Why should root be allowed to override?
> I would query the name too. Right now your assumption is 'shmem only' but
> that might change with other future use cases or types (eg some driver
> file handles) so SHMEM_ in the fcntl might become misleading.
I'm fine with F_SET/GET_SEALS. But given you suggested requiring
MFD_ALLOW_SEALS for sealing, I don't see why we couldn't limit this
interface entirely to memfd_create().
> Whether you want some way to undo a seal without an exclusive reference as
> the file owner is another question.
No. You are never allowed to undo a seal but with an exclusive
reference. This interface was created for situations _without_ any
trust relationship. So if the owner is allowed to undo seals, the
interface doesn't make any sense. The only options I see is to not
allow un-sealing at all (which I'm fine with) or tracking users (which
is way too much overhead).
Thanks
David
next prev parent reply other threads:[~2014-03-20 15:12 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-19 19:06 [PATCH 0/6] File Sealing & memfd_create() David Herrmann
2014-03-19 19:06 ` [PATCH 1/6] fs: fix i_writecount on shmem and friends David Herrmann
2014-03-19 19:06 ` [PATCH 2/6] shm: add sealing API David Herrmann
2014-03-19 19:06 ` [PATCH 3/6] shm: add memfd_create() syscall David Herrmann
2014-03-20 8:47 ` Cyrill Gorcunov
2014-03-20 9:01 ` Pavel Emelyanov
2014-03-20 11:29 ` David Herrmann
2014-03-20 11:50 ` Pavel Emelyanov
2014-03-20 19:22 ` John Stultz
2014-04-02 13:38 ` Konstantin Khlebnikov
2014-04-02 14:18 ` David Herrmann
2014-04-02 14:52 ` Konstantin Khlebnikov
2014-04-10 19:07 ` Andy Lutomirski
2014-03-19 19:06 ` [PATCH 4/6] selftests: add memfd_create() + sealing tests David Herrmann
2014-03-19 19:06 ` [PATCH man-pages 5/6] fcntl.2: document SHMEM_SET/GET_SEALS commands David Herrmann
2014-03-19 19:06 ` [PATCH man-pages 6/6] memfd_create.2: add memfd_create() man-page David Herrmann
2014-03-20 2:55 ` [PATCH 0/6] File Sealing & memfd_create() Greg Kroah-Hartman
2014-03-20 3:49 ` Linus Torvalds
2014-03-20 8:07 ` David Herrmann
2014-03-20 14:41 ` One Thousand Gnomes
2014-03-20 15:12 ` David Herrmann [this message]
2014-03-20 15:26 ` One Thousand Gnomes
2014-03-20 15:32 ` tytso
2014-03-20 15:39 ` One Thousand Gnomes
2014-03-20 15:48 ` David Herrmann
2014-03-20 16:38 ` tytso
2014-04-10 19:14 ` Andy Lutomirski
2014-04-10 20:32 ` Theodore Ts'o
2014-04-10 20:37 ` Andy Lutomirski
2014-04-10 20:49 ` David Herrmann
2014-04-10 21:16 ` Andy Lutomirski
2014-04-10 22:57 ` David Herrmann
2014-04-10 23:05 ` Andy Lutomirski
2014-04-10 23:16 ` David Herrmann
2014-04-10 23:32 ` Andy Lutomirski
2014-04-20 15:03 ` Pavel Machek
2014-06-17 9:48 ` Florian Weimer
2014-06-17 16:21 ` Andy Lutomirski
2014-04-10 14:45 ` Colin Walters
2014-04-10 19:15 ` Andy Lutomirski
2014-04-10 19:45 ` Colin Walters
2014-04-11 6:09 ` Alex Elsayed
2014-04-08 13:00 ` Florian Weimer
2014-04-09 21:31 ` David Herrmann
2014-04-22 9:10 ` Florian Weimer
2014-04-22 11:55 ` David Herrmann
2014-04-22 12:44 ` Florian Weimer
2014-04-22 12:55 ` David Herrmann
2014-04-10 19:17 ` Andy Lutomirski
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CANq1E4Ro8bsgp1QS_Qf9KKBAMZH+joMW5DmfyZ4OBJuTxdXCZA@mail.gmail.com \
--to=dh.herrmann@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=desrt@desrt.ca \
--cc=dri-devel@lists.freedesktop.org \
--cc=gnomes@lxorguk.ukuu.org.uk \
--cc=greg@kroah.com \
--cc=hannes@cmpxchg.org \
--cc=hughd@google.com \
--cc=k.lewandowsk@samsung.com \
--cc=kay@vrfy.org \
--cc=lennart@poettering.net \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mtk.manpages@gmail.com \
--cc=tj@kernel.org \
--cc=torvalds@linux-foundation.org \
--cc=viro@zeniv.linux.org.uk \
--cc=zonque@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).