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From: Roland McGrath <roland@redhat.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
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Cc: Oleg Nesterov <oleg@redhat.com>, Peter Zijlstra <peterz@infradead.org>,
       Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
       Ingo Molnar <mingo@elte.hu>, Andrew Morton <akpm@linux-foundation.org>,
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       Ananth N Mavinakayanahalli <ananth@in.ibm.com>,
       Jim Keniston <jkenisto@linux.vnet.ibm.com>,
       Frederic Weisbecker <fweisbec@gmail.com>,
       "Frank Ch. Eigler" <fche@redhat.com>,
       LKML <linux-kernel@vger.kernel.org>, Mel Gorman <mel@csn.ul.ie>,
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Subject: Re: [PATCH v2 7/11] Uprobes Implementation
In-Reply-To: Linus Torvalds's message of  Thursday, 13 May 2010 12:59:23 -0700 <alpine.LFD.2.00.1005131256050.3711@i5.linux-foundation.org>
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References: <20100413183537.GA17538@redhat.com>
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	<20100419193139.GA24080@redhat.com>
	<20100420124358.GA20675@linux.vnet.ibm.com>
	<20100420153023.GA9351@redhat.com>
	<20100421065948.GA5440@linux.vnet.ibm.com>
	<20100421160515.GA11321@redhat.com>
	<20100422133154.GA10776@linux.vnet.ibm.com>
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	<1273610723.1810.105.camel@laptop>
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Emacs: more than just a Lisp interpreter, a text editor as well!
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Date: Thu, 13 May 2010 17:56:51 -0700 (PDT)
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> so arguably it would be good to just make the rule be that you cannot 
> probe a shared mapping. Because whatever you do, it's always the wrong 
> thing.

Agreed.  Or, if you do, it's doing something entirely different and should
be in an interface where you're explicitly attaching it generically to the
file (what's being shared) without regard to any individual process.  But,
as you mentioned, shared, executable mappings are well outside the normal
case and there is no reason to think that a first (or fourth) version of
anything needs to support them at all.


Thanks,
Roland