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Subject: Re: [PATCH] Fix mmap_kmem (was: [question] What's the difference 
	between /dev/kmem and /dev/mem)
From: Arjan van de Ven <arjan@infradead.org>
To: Andi Kleen <ak@suse.de>
Cc: Linus Torvalds <torvalds@osdl.org>, linux-kernel@vger.kernel.org,
       hugh@veritas.com
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Date: Fri, 12 Aug 2005 19:56:26 +0200
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On Fri, 2005-08-12 at 18:54 +0200, Andi Kleen wrote:
> Linus Torvalds <torvalds@osdl.org> writes:
> > 
> > I'm actually more inclined to try to deprecate /dev/kmem.. I don't think 
> > anybody has ever really used it except for some rootkits. 
> 
> I don't think that's true.

got any examples ?

>  
> > So I'd be perfectly happy to fix this, but I'd be even happier if we made 
> > the whole kmem thing a config variable (maybe even default it to "off").
> 
> Acessing vmalloc in /dev/mem would be pretty awkward. Yes it doesn't
> also work in mmap of /dev/kmem, but at least in read/write.
> There are quite a lot of scripts that use it for kernel debugging
> like dumping variables. And for that you really want to access modules
> and vmalloc. And it's much easier to parse than /proc/kcore

but you can stick gdb on /proc/kcore...