Subject: Re: [3/3 PATCH] Kprobes: User space probes support- single
	stepping out-of-line
From: Arjan van de Ven <arjan@infradead.org>
To: Andrew Morton <akpm@osdl.org>
Cc: prasanna@in.ibm.com, ak@suse.de, davem@davemloft.net, suparna@in.ibm.com,
       richardj_moore@uk.ibm.com, linux-kernel@vger.kernel.org
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Date: Mon, 20 Mar 2006 12:24:01 +0100
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> And we'll need to actually *be* in-atomic.  That means we need an
> open-coded inc_preempt_count() and dec_preempt_count() in there and I don't
> see them.
> 

..

> Why is VM_LOCKED being set? (It needs a comment).
> 
> Where does it get unset?


if this is an attempt to make the copy_in_atomic to be atomic, then it
is a bug; the user can unset this bit after all via mprotect, even from
another thread, and concurrently. UnGood(tm).


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