Re: Emergency Unmount...

[Perego Paolo <sponge@tiscalinet.it>]

On Wed, Apr 04, 2001 at 01:30:38PM +0200, Erik Mouw wrote:
> On Wed, Apr 04, 2001 at 11:55:02AM +0200, Perego Paolo wrote:
[snip]
> Hmm, security through obscurity has never been a good idea, and it's
The point is that root needs a password to put MOD_USE_COUNT to 0 ( echoing
that in a char dev ) and he needs to re-enter the password the same way, if he
wants cleanup-module to exit fairly. I would prevent a malicious user puts
MOD_USE_COUNT to 0 using /dev/kmem and then removing the module.
I can't figure out what do you means talking about obscurity :)

> quite easy to work around your "protection" scheme. Once I gain root
I know it. However it's just my thesis work, some lacks are allowed aren't
there? :)

[snip]
> > So my question is: how can I walk throught the mounted block devices in order
> > to unmount them fairly? I've alredy called sys_sync() to sync all the disks.
> 
> Have a look at the MAGIC_SYSRQ code which does exactly what you want
> (alt-sysrq-u).
Already done. The point is that go_sync function ( linux/drivers/char/sysrq.c
) is not exported as symbol. I can't rip off that code because it referes to
other symbols not exported by the kernel.

-- 
$>cd /pub
$>more beer

(0>
//\  Perego Paolo <sponge@tiscalinet.it> Tutor at D.S.I. University of Milan
V_/_ 'The future will not remember, the past doesn't forget.'
I'm Linux zion 2.4.2 #12 mar feb 27 11:10:40 CET 2001 i586

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