Re: [PATCH 5/9] jump label: Addregister_jump_label_key/unregister_jump_label_key

From: Peter Zijlstra
Date: Mon Oct 18 2010 - 08:05:48 EST


On Fri, 2010-10-15 at 23:13 +0200, Peter Zijlstra wrote:
> On Fri, 2010-10-15 at 17:09 -0400, Steven Rostedt wrote:
> > On Fri, 2010-10-15 at 23:03 +0200, Peter Zijlstra wrote:
> >
> > > Urgh, this sucks.. :-(
> > >
> > > So now we have to actually track all JUMP_LABEL() sites and call
> > > register muck on them.. even though we already track them through the
> > > special data section.
> > >
> > > Is there really no way around this?
> >
> > I'll take a look to see if we can monkey with magic and automate it.
>
> So the problem is something like:
>
> core kernel:
>
> jump_label_enable()
>
> module:
>
> JUMP_LABEL()
>
> And then because we don't have a proper __jump_table section, the
> jump_label_enable() won't properly work?
>
> Why not let jump_label_enable() add a dummy entry with the enabled bit
> and once you load the module merge the real entry into it.

Or actually use the value of the key pointer.. it would mean either
standardizing the size (int/atomic_t would work), or using a version of
the fallback JUMP_LABEL implementation to sort out the type issues.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/