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From: Michael Buesch <mb@bu3sch.de>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: Really good idea to allow mmap(0, FIXED)?
Date: Fri, 6 Oct 2006 16:44:32 +0200	[thread overview]
Message-ID: <200610061644.33267.mb@bu3sch.de> (raw)
In-Reply-To: <1160085480.1607.32.camel@localhost.localdomain>

On Thursday 05 October 2006 23:58, Alan Cox wrote:
> Ar Iau, 2006-10-05 am 20:59 +0200, ysgrifennodd Michael Buesch:
> > Is is really a good idea to allow processes to remap something
> > to address 0?
> 
> It is very useful indeed. Consider for example dosemu.

Ok, good point.

> > 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.

-- 
Greetings Michael.

  reply	other threads:[~2006-10-06 14:44 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-10-05 18:59 Really good idea to allow mmap(0, FIXED)? 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 [this message]
2006-10-07 11:23     ` Pavel Machek
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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