From: Cyrill Gorcunov <gorcunov@gmail.com>
To: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Herbert Xu <herbert@gondor.hengli.com.au>,
Tejun Heo <tj@kernel.org>,
linux-kernel@vger.kernel.org,
Pavel Emelyanov <xemul@parallels.com>,
Glauber Costa <glommer@parallels.com>,
Andi Kleen <andi@firstfloor.org>,
Matt Helsley <matthltc@us.ibm.com>,
Pekka Enberg <penberg@kernel.org>,
Eric Dumazet <eric.dumazet@gmail.com>,
Vasiliy Kulikov <segoon@openwall.com>,
Andrew Morton <akpm@linux-foundation.org>,
Alexey Dobriyan <adobriyan@gmail.com>,
"David S. Miller" <davem@davemloft.net>
Subject: Re: [patch 1/4] Add routine for generating an ID for kernel pointer
Date: Sat, 31 Dec 2011 11:51:02 +0400 [thread overview]
Message-ID: <20111231075102.GQ4806@moon> (raw)
In-Reply-To: <4EFE4E89.6000607@gmail.com>
On Fri, Dec 30, 2011 at 06:51:37PM -0500, KOSAKI Motohiro wrote:
...
> >
> >Guys, this become more and more complex, finally I fear someone
> >propose to do ideal hashing run-time ;) Maybe we can step back and
> >live with root-only and plain pointers here? I'm not sure who else
> >might need such facility except us, and if once there will be a candidate
> >-- we could take a look on hashing again and provide safe hashes there. No?
>
> But recently kernel security fashion are, we don't expose a kernel
> pointer at all even though the file is root only. I'm not sure how
> much effective such fashion. but you seems run opposite way.
>
> I doubt user land can implement good comparison way. Why you gave up
> Andrew's sys_are_these_files_the_same() idea?
>
Because of speed, as Pavel mentioned
|
| With this the complexity of determining sharing for N files scattered across
| several tasks would be N^2, since we'll have to compare each file to each file.
|
| On the other hand having just N IDs at hands would allow us to use more
| efficient algorithms resulting in e.g. N*log(N) complexity.
|
Cyrill
next prev parent reply other threads:[~2011-12-31 7:51 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-23 12:47 [patch 0/4] generic object ids, v2 Cyrill Gorcunov
2011-12-23 12:47 ` [patch 1/4] Add routine for generating an ID for kernel pointer Cyrill Gorcunov
2011-12-27 23:23 ` Andrew Morton
2011-12-28 7:42 ` Cyrill Gorcunov
2011-12-28 9:42 ` Andrew Morton
2011-12-28 9:43 ` Cyrill Gorcunov
2011-12-28 9:47 ` Pavel Emelyanov
2011-12-28 10:41 ` Cyrill Gorcunov
2011-12-27 23:33 ` Andrew Morton
2011-12-28 0:48 ` Randy Dunlap
2011-12-28 7:24 ` Cyrill Gorcunov
2011-12-27 23:54 ` Valdis.Kletnieks
2011-12-28 0:02 ` Andrew Morton
2011-12-28 7:22 ` Cyrill Gorcunov
2011-12-28 16:06 ` Tejun Heo
2011-12-28 16:18 ` Cyrill Gorcunov
2011-12-28 16:26 ` Tejun Heo
2011-12-28 16:40 ` Cyrill Gorcunov
2011-12-28 16:45 ` Tejun Heo
2011-12-28 16:53 ` Cyrill Gorcunov
2011-12-28 17:01 ` Tejun Heo
2011-12-28 17:14 ` Cyrill Gorcunov
2011-12-29 14:24 ` Cyrill Gorcunov
2011-12-29 16:14 ` Tejun Heo
2011-12-29 16:24 ` Cyrill Gorcunov
2011-12-30 0:23 ` Herbert Xu
2011-12-30 7:36 ` Cyrill Gorcunov
2011-12-30 20:31 ` KOSAKI Motohiro
2011-12-30 20:48 ` Cyrill Gorcunov
2011-12-30 23:51 ` KOSAKI Motohiro
2011-12-31 7:51 ` Cyrill Gorcunov [this message]
2012-01-02 12:18 ` bastien ROUCARIES
2012-01-02 21:14 ` Cyrill Gorcunov
2011-12-31 4:55 ` Kyle Moffett
2011-12-31 7:57 ` Cyrill Gorcunov
2011-12-23 12:47 ` [patch 2/4] proc: Show namespaces IDs in /proc/pid/ns/* files Cyrill Gorcunov
2012-01-04 6:02 ` Eric W. Biederman
2012-01-04 11:26 ` Cyrill Gorcunov
2012-01-04 17:56 ` Eric W. Biederman
2012-01-04 18:19 ` Cyrill Gorcunov
2011-12-23 12:47 ` [patch 3/4] proc: Show open file ID in /proc/pid/fdinfo/* Cyrill Gorcunov
2011-12-23 12:47 ` [patch 4/4] proc: Show IDs of objects cloned with CLONE_ in proc Cyrill Gorcunov
-- strict thread matches above, loose matches on Subject: below --
2011-12-22 12:56 [patch 0/4] kernel generic object IDs series Cyrill Gorcunov
2011-12-22 12:56 ` [patch 1/4] Add routine for generating an ID for kernel pointer Cyrill Gorcunov
2011-12-28 16:51 ` Alan Cox
2011-12-28 17:05 ` Cyrill Gorcunov
2011-12-28 17:21 ` Alan Cox
2011-12-28 17:35 ` Cyrill Gorcunov
2011-12-28 19:48 ` Cyrill Gorcunov
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