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Subject: Re: [PATCH] tracing/profile: Fix profile_disable vs module_unload
From: Peter Zijlstra <peterz@infradead.org>
To: Li Zefan <lizf@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>, Steven Rostedt <rostedt@goodmis.org>,
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       LKML <linux-kernel@vger.kernel.org>,
       Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
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Date: Wed, 26 Aug 2009 09:01:32 +0200
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On Wed, 2009-08-26 at 08:46 +0200, Peter Zijlstra wrote:

> Aahh, I see the bug, its only ftrace that knows about the module, not
> tracepoints themselves, _that_ needs fixing.

You could possibly do something like:

 struct module *tp_mod = __module_address(&some_tp_symbol);
 struct module *cb_mod = __module_text_address(func);

 if (tp_mod && tp_mod != cb_mod) {
	ret = try_get_module(tp_mod);
	if (ret)
		goto fail;
 }

in register_trace_##name() or thereabout.