From: Pavel Machek <pavel@ucw.cz>
To: Michael Buesch <mb@bu3sch.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: Really good idea to allow mmap(0, FIXED)?
Date: Sat, 7 Oct 2006 11:23:01 +0000 [thread overview]
Message-ID: <20061007112301.GB4277@ucw.cz> (raw)
In-Reply-To: <200610061644.33267.mb@bu3sch.de>
Hi!
>
> > > Besides that, I currently don't see a valid reason to mmap address 0.
> > >
> > > Comments?
> >
> > User zero is not neccessarily mapped at kernel zero so your argument
> > isn't portable either.
>
> Eh, so what about the following.
> We _have_ arches which map user zero to kernel zero. What about
> specialcasing that on a per-arch case. So remapping user zero to
> something else in kernel.
Just add some magic constant on architectures you care about... make
user 0 start at 4mb in kernel... and you get your security hardened
kernel w/o breaking dosemu. All you need is to create a patch :-)
--
Thanks for all the (sleeping) penguins.
next prev parent reply other threads:[~2006-10-07 11:23 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-10-05 18:59 Michael Buesch
2006-10-05 19:50 ` linux-os (Dick Johnson)
2006-10-06 14:40 ` Michael Buesch
2006-10-05 21:58 ` Alan Cox
2006-10-06 14:44 ` Michael Buesch
2006-10-07 11:23 ` Pavel Machek [this message]
2006-10-05 23:55 ` David Wagner
2006-10-06 4:34 ` Jeremy Fitzhardinge
2006-10-06 5:39 ` Jan Engelhardt
2006-10-06 19:47 ` David Wagner
2006-10-06 7:25 ` Arjan van de Ven
2006-10-06 10:36 ` Mikael Pettersson
2006-10-06 11:20 ` Arjan van de Ven
2006-10-06 19:43 ` David Wagner
2006-10-08 0:22 ` Jeremy Fitzhardinge
2006-10-08 2:03 ` David Wagner
2006-10-08 19:18 ` Michael Buesch
2006-10-06 14:55 ` Michael Buesch
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