linux-kernel - Re: [PATCH] driver-core: devtmpfs - driver core maintained /dev tmpfs

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <49FF3A26.3030407@googlemail.com>
Date:	Mon, 04 May 2009 20:55:34 +0200
From:	Michael Riepe <michael.riepe@...glemail.com>
To:	Kay Sievers <kay.sievers@...y.org>
CC:	Lars Marowsky-Bree <lmb@...e.de>,
	Alan Jenkins <sourcejedi.lkml@...glemail.com>,
	Alan Cox <alan@...rguk.ukuu.org.uk>, Greg KH <greg@...ah.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	Jan Blunck <jblunck@...e.de>
Subject: Re: [PATCH] driver-core: devtmpfs - driver core maintained /dev tmpfs



Kay Sievers wrote:
> On Mon, May 4, 2009 at 19:54, Michael Riepe
> <michael.riepe@...glemail.com> wrote:
> 
>>>The problem is not the missing events, they could be pretty easily
>>>recovered from sysfs with just another special hack to run at bootup -
>>>it's the time it takes to bring up the engine to bootstrap /dev, to
>>>allow us to start any other process which looks for devices. Today,
>>>udev mounts /dev as a tmpfs, and at that point it is obviously empty,
>>>and needs to be filled, and nothing else can reliably run at that
>>>time.
>>
>>And what about mounting /dev from an already populated image? Or, even
>>faster, using the /dev directory of the root fs? That way, the device
>>nodes would be present as soon as / is mounted, without any additional
>>overhead, except the very first time the system boots (in case you
>>choose not to populate /dev with a default set of device nodes in advance).
> 
> 
> Dynamic device numbers! A static /dev does not work at all for many
> subsystems, not to mention the risk you take by talking to the wrong
> device pointed to, by your incorrect static device nodes. It's not an
> option at all today, and it will get much worse in the future.

Maybe it's just me, but my devices end up being numbered the same after
every reboot. Unless I add or remove devices to/from the system, of course.

Unfortunately, that doesn't mean that it will always stay that way.

-- 
Michael "Tired" Riepe <michael.riepe@...glemail.com>
X-Tired: Each morning I get up I die a little
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/