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Subject: Re: [PATCH] tracing/profile: Fix profile_disable vs module_unload
From: Peter Zijlstra <peterz@infradead.org>
To: Ingo Molnar <mingo@elte.hu>
Cc: Li Zefan <lizf@cn.fujitsu.com>, Steven Rostedt <rostedt@goodmis.org>,
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       LKML <linux-kernel@vger.kernel.org>
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Date: Tue, 25 Aug 2009 16:52:43 +0200
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On Tue, 2009-08-25 at 12:47 +0200, Peter Zijlstra wrote:
> On Tue, 2009-08-25 at 12:39 +0200, Ingo Molnar wrote:
> 
> > > Do you really wish to burden every tracepoint user with the extra 
> > > logic needed to deal with modules?
> > 
> > Not necessarily - i'm just outlining why i think that the 'dont 
> > allow subsystems to utilize tracepoint callbacks' is a restriction 
> > we should not live with voluntarily.
> 
> Well, unless someone has a bright idea that's what it comes down to. 

OK, I still think modules probing their own tracepoints its stupid [*],
but what you could do is iterate the tracepoint's callback list and see
if it has a callback outside of the module code section and then fail
the unload.

[*] in the really utterly fundamentally wrong stupid class.