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Date: Tue, 5 Jul 2022 10:48:52 -0500
From: Segher Boessenkool <segher@kernel.crashing.org>
To: Christophe Leroy <christophe.leroy@csgroup.eu>
Subject: Re: [RFC PATCH v3 11/12] powerpc: Remove unreachable() from WARN_ON()
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On Mon, Jul 04, 2022 at 12:34:08PM +0000, Christophe Leroy wrote:
> Le 04/07/2022 à 13:45, Peter Zijlstra a écrit :
> > I'm somewhat confused; how is an empty STT_FUNC a valid construct on
> > Power?
> 
> So am I. It is likely not a valid construct, but that's what GCC seems 
> to generate when you call annotate_unreachable().

It is a valid construct on (almost) all targets.  If the user chooses to
have executable code terminate in limbo, that is what the compiler will
do (and this can result in a code symbol with size 0).  Compare this to
data symbols with no size, the situation is quite similar.


Segher