Subject: Re: [3/3 PATCH] Kprobes: User space probes support- single
	stepping out-of-line
From: Arjan van de Ven <arjan@infradead.org>
To: prasanna@in.ibm.com
Cc: Andrew Morton <akpm@osdl.org>, 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 15:13:48 +0100
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On Mon, 2006-03-20 at 19:35 +0530, Prasanna S Panchamukhi wrote:
> On Mon, Mar 20, 2006 at 12:24:01PM +0100, Arjan van de Ven wrote:
> > 
> > Lines: 16
> > 
> > > 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. U
> 
> You are right, the purpose was to make copy_to_user_inatomic() to suceed. I
> need to look at this issue again. Any suggestions?

get_user_pages seems to be the only viable API for this..


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