From: Jon Masters <jonathan@jonmasters.org>
To: Ray Lee <ray-lk@madrabbit.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>,
tvrtko.ursulin@sophos.com, Al Viro <viro@ftp.linux.org.uk>,
Casey Schaufler <casey@schaufler-ca.com>,
Christoph Hellwig <hch@infradead.org>,
linux-kernel@vger.kernel.org, Valdis.Kletnieks@vt.edu
Subject: Re: Out of tree module using LSM
Date: Thu, 29 Nov 2007 13:56:51 -0500 [thread overview]
Message-ID: <1196362612.6473.98.camel@perihelion> (raw)
In-Reply-To: <2c0942db0711291040j4ce48acagb753b64c4b8c1357@mail.gmail.com>
On Thu, 2007-11-29 at 10:40 -0800, Ray Lee wrote:
> On Nov 29, 2007 9:36 AM, Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:
> > > closed. But more importantly further access to it can be blocked until
> > > appropriate actions are taken which also applies with your example, no? Is
> >
> > That bit is hard- very hard.
>
> In some sense it seems like the same problem faced by dynamic
> translators such as Qemu. They really want to vet a dirtied or faulted
> page before allowing the app to run unhindered. It's be nice to have
> some way to do that without virtualizing the whole of userspace.
Like I hinted at, you can't just "vet a page". Because a page alone is
meaningless garbage, unless it happens to be an extremely small program,
with headers, all nicely aligned. Most likely you don't know if a random
page of data is code from a COFF file, ELF file, or some random crap I
typed in at a terminal after having too much coffee.
So. You'd need to scan *all the pages* of *the entire file*, every time
that you performed any type of operation. Hence, that idea is completely
out right away. The on-access scanning isn't perfect, but it's probably
about as good as you can get and still have a reasonably usable system.
Jon.
next prev parent reply other threads:[~2007-11-29 18:57 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-11-28 12:42 Out of tree module using LSM Tvrtko A. Ursulin
2007-11-28 14:41 ` Christoph Hellwig
2007-11-28 16:38 ` Casey Schaufler
2007-11-28 16:46 ` Christoph Hellwig
2007-11-28 17:39 ` Stephen Hemminger
2007-11-28 18:22 ` tvrtko.ursulin
2007-11-28 19:50 ` Alan Cox
2007-11-29 16:12 ` tvrtko.ursulin
2007-11-29 0:12 ` James Morris
2007-11-29 16:27 ` Jon Masters
2007-11-29 16:51 ` Greg KH
2007-11-29 16:51 ` Stephen Hemminger
2007-11-29 16:52 ` Jan Engelhardt
2007-11-29 0:51 ` Jan Engelhardt
2007-11-29 1:45 ` Casey Schaufler
2007-11-28 18:15 ` Valdis.Kletnieks
2007-11-28 18:30 ` Al Viro
2007-11-29 0:38 ` Greg KH
2007-11-29 0:53 ` Jan Engelhardt
2007-11-29 1:07 ` Greg KH
2007-11-29 16:36 ` Jon Masters
2007-11-29 16:47 ` Greg KH
2007-11-29 16:53 ` Jan Engelhardt
2007-11-29 16:57 ` Christoph Hellwig
2007-11-29 17:27 ` Alan Cox
2007-11-29 22:58 ` Andi Kleen
2007-12-08 10:50 ` Pavel Machek
2007-11-29 17:03 ` Greg KH
2007-11-29 17:35 ` Ray Lee
2007-11-29 17:45 ` Greg KH
2007-11-29 18:03 ` Ray Lee
2007-11-29 18:19 ` Justin Banks
2007-11-29 18:38 ` Jon Masters
2007-11-29 17:51 ` Al Viro
2007-11-29 17:05 ` Jon Masters
2007-11-29 17:14 ` Greg KH
2007-11-29 16:26 ` tvrtko.ursulin
2007-11-29 17:36 ` Alan Cox
2007-11-29 18:40 ` Ray Lee
2007-11-29 18:56 ` Jon Masters [this message]
2007-11-29 19:11 ` Ray Lee
2007-11-29 19:45 ` Jon Masters
2007-11-29 20:56 ` Valdis.Kletnieks
2007-11-29 22:08 ` Al Viro
2007-11-30 0:50 ` James Morris
2007-11-29 23:31 ` Jon Masters
2007-11-29 21:45 ` Alan Cox
2007-11-29 22:12 ` Justin Banks
2007-11-30 1:48 ` Al Viro
2007-11-30 15:37 ` Justin Banks
2007-11-29 23:34 ` Jon Masters
2007-11-30 6:20 ` Valdis.Kletnieks
2007-11-30 13:30 ` Alan Cox
2007-11-29 21:09 ` Andi Kleen
2007-11-28 19:20 ` Andi Kleen
2007-11-28 19:52 ` Alan Cox
2007-11-28 20:05 ` Valdis.Kletnieks
2007-11-29 16:39 ` tvrtko.ursulin
2007-12-01 8:43 ` Pavel Machek
2007-12-02 19:44 ` Valdis.Kletnieks
2007-12-02 20:02 ` Arjan van de Ven
2007-12-02 20:06 ` Andi Kleen
2007-12-02 20:22 ` Pavel Machek
2007-12-02 21:09 ` Valdis.Kletnieks
2007-12-02 21:56 ` Pavel Machek
2007-12-02 23:15 ` Jan Engelhardt
2007-12-02 23:23 ` Pavel Machek
2007-11-29 0:58 ` Greg KH
2007-11-30 20:52 Crispin Cowan
2007-11-30 21:36 ` James Morris
2007-11-30 23:52 ` Crispin Cowan
2007-12-01 0:05 ` James Morris
[not found] <9uzZr-6iz-19@gated-at.bofh.it>
[not found] ` <9uUrm-5w3-27@gated-at.bofh.it>
[not found] ` <9uVGz-7uQ-19@gated-at.bofh.it>
[not found] ` <9uWCC-xI-13@gated-at.bofh.it>
[not found] ` <9uWMp-Ix-13@gated-at.bofh.it>
[not found] ` <9uX5A-1rs-1@gated-at.bofh.it>
[not found] ` <9uXyK-24f-23@gated-at.bofh.it>
2007-12-03 22:45 ` Bodo Eggert
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=1196362612.6473.98.camel@perihelion \
--to=jonathan@jonmasters.org \
--cc=Valdis.Kletnieks@vt.edu \
--cc=alan@lxorguk.ukuu.org.uk \
--cc=casey@schaufler-ca.com \
--cc=hch@infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=ray-lk@madrabbit.org \
--cc=tvrtko.ursulin@sophos.com \
--cc=viro@ftp.linux.org.uk \
/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).