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Message-ID: <526340.68353.qm@web50103.mail.re2.yahoo.com>
Date: Mon, 20 Jul 2009 14:02:10 -0700 (PDT)
From: Doug Thompson <norsk5@yahoo.com>
Subject: Re: [PATCH 07/14] mce3: pass mce info to EDAC for decoding
To: Andi Kleen <andi@firstfloor.org>, "H. Peter Anvin" <hpa@zytor.com>
Cc: Borislav Petkov <borislav.petkov@amd.com>, mingo@elte.hu,
       tglx@linutronix.de, aris@redhat.com, linux-kernel@vger.kernel.org,
       x86@kernel.org
In-Reply-To: <4A64D0F2.7050009@zytor.com>
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--- On Mon, 7/20/09, H. Peter Anvin <hpa@zytor.com> wrote:

> From: H. Peter Anvin <hpa@zytor.com>
> Subject: Re: [PATCH 07/14] mce3: pass mce info to EDAC for decoding
> To: "Andi Kleen" <andi@firstfloor.org>
> Cc: "Doug Thompson" <norsk5@yahoo.com>, "Borislav Petkov" <borislav.petkov@amd.com>, mingo@elte.hu, tglx@linutronix.de, aris@redhat.com, linux-kernel@vger.kernel.org, x86@kernel.org
> Date: Monday, July 20, 2009, 2:17 PM
> Andi Kleen wrote:
> >> The goal is to have a default handler within the
> kernel and a more specific handler in a module after it has
> loaded. Using the weak symbol as a mechanism to do that. I
> haven't used that, so I don't know if it works.
> > 
> > weak symbols don't work over kernel modules.
> > 
> 
> For modules, you typically have to have a callback to
> update an internal
> function pointer.? If you think about it, it's pretty
> obvious -- a weak
> symbol changes the behavior at link time, but it's still a
> static call.
>  If you want modules to change the behavior, you're talking
> about a
> *dynamic* change -- the call will point to different things
> at different
> points in time -- so you need another mechanism, i.e.
> function pointers.
> 
> ??? -hpa

Thanks, that is exactly what I just posted in another reply.

now I understand weak symbols a bit better now as well

doug t 
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