Re: [PATCH 2/2] Rewrite jump_label.c to use binary search

From: Mathieu Desnoyers
Date: Wed Sep 22 2010 - 11:07:51 EST


* Mathieu Desnoyers (mathieu.desnoyers@xxxxxxxxxx) wrote:
> * Andi Kleen (andi@xxxxxxxxxxxxxx) wrote:
> >
> > >
> > >>> + for (; entry < stop && entry->key == key; entry++)
> > >>> + if (kernel_text_address(entry->code))
> > >>
> > >> This does not work for modules I'm afraid, only for the core kernel. You
> > >> should test for __module_text_address() somewhere.
> > >
> > > I thought it was shared now, but ok.
> >
> > Double checked. This is ok because kernel_text_address()
> > already checks for modules. You were probably thinking
> > of __kernel_text_address()
>
> Ah right,
>
> Although we have another problem:
>
> __module_text_address() includes module init text, which defeats the
> purpose of the check put in there by Jason.
>
> So the check works for the core kernel, but not for modules.

So, we have this issue, but I also have a question for Jason: what
happens if someone puts static jump in a function declared in the __init
section of the core kernel/module ? Can we enable them at early boot ?

Thanks,

Mathieu

>
> Mathieu
>
> >
> > -Andi
> >
>
> --
> Mathieu Desnoyers
> Operating System Efficiency R&D Consultant
> EfficiOS Inc.
> http://www.efficios.com

--
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com
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