From: Clemens Kolbitsch <clemens.kol@gmx.at>
To: linux-kernel@vger.kernel.org
Subject: Re: Forbid deletion of memory mappings
Date: Thu, 30 Aug 2007 23:41:09 +0200 [thread overview]
Message-ID: <200708302341.09459.clemens.kol@gmx.at> (raw)
In-Reply-To: <Pine.LNX.4.64.0708302333320.2460@twin.jikos.cz>
On Thursday 30 August 2007 23:34:52 you wrote:
> On Thu, 30 Aug 2007, Clemens Kolbitsch wrote:
> > is there no way to tell the kernel, that a certain mapping must not be
> > removed, no matter what (except of course an explicit call to sys_unmap,
> > of course)?
>
> I don't seem to get what is the issue here. Your mapping is not removed,
> only the VMAs are merged together into one larger VMA if they have
> neighbouring address ranges and compatible protection bits. See
> vma_merge().
the thing is that they are not. the kernel chooses to REPLACE my mapping.
consider the user-space code:
mmap(0xaaaa0000, 0x3000, MAP_FIXED, ...);
mmap(0xaaaa1000, 0x4000, MAP_FIXED, ...);
here, the second call to mmap will shorten the first mapping to 0x1000 bytes
and create one big vma with size 0x5000 bytes.
is there a way to tell it that the second mmap MUST fail?
next prev parent reply other threads:[~2007-08-30 21:41 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-08-30 16:44 Clemens Kolbitsch
2007-08-30 17:07 ` Jiri Kosina
2007-08-30 17:09 ` Clemens Kolbitsch
2007-08-30 21:32 ` Clemens Kolbitsch
2007-08-30 21:34 ` Jiri Kosina
2007-08-30 21:41 ` Clemens Kolbitsch [this message]
2007-08-30 21:50 ` Valdis.Kletnieks
2007-08-30 22:05 ` Clemens Kolbitsch
2007-09-04 10:17 ` Helge Hafting
2007-09-04 10:29 ` Clemens Kolbitsch
2007-09-04 14:53 ` linux-os (Dick Johnson)
2007-08-30 21:55 ` Jiri Kosina
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