Messages in this thread | | | Date | Wed, 26 Aug 2009 15:10:44 +0800 | From | Li Zefan <> | Subject | Re: [PATCH] tracing/profile: Fix profile_disable vs module_unload |
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Peter Zijlstra wrote: > 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. >
Actually I tried it, but it didn't work. As I said, You can't find any tp symbol when registering tp callback. The same example again:
In module bar, we have register_trace_foo() In module foo, we have DEFINE_TRACE(foo) and trace_foo().
bar doesn't know any symbol of foo, so it can't bump foo's refcnt,
*Note: you can load module bar without loading module foo*
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