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Date: Wed, 25 Feb 2009 00:46:44 -0500
From: Kyle McMartin <kyle@infradead.org>
To: Sam Ravnborg <sam@ravnborg.org>
Subject: Re: [PATCH/RFC] powerpc: avoid generating .eh_frame sections with
	gcc-4.4
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On Wed, Feb 25, 2009 at 06:47:07AM +0100, Sam Ravnborg wrote:
> > On ppc64 (at least) gcc-4.4 is defaulting to generating .eh_frame
> > sections, which are, for the kernel, fairly pointless. Additionally, on
> > ppc64 this generates a relocation format which the kernel module loader
> > does not currently support (R_PPC64_REL32.)
> > 
> > Alexandre Oliva verifies that -fno-dwarf2-cfi-asm prevents this
> > .eh_frame section from being generated.
> > 
> > These seem to be used for unwinding, but it doesn't look like we
> > currently use them anywhere. (In fact, we explicitly dump them in the
> > x86_64 linker script.)
> > 
> > If these .eh_frame sections are eventually used, adding a per-arch
> > CONFIG_WANT_UNWIND check would be trivial.
> > 
> > (This was reported against Fedora, which appears to be the only distro
> > doing any building against gcc-4.4 at present: RH bz#486545.)
> > 
> > Signed-off-by: Kyle McMartin <kyle@redhat.com>
> > Cc: roland@redhat.com
> > Cc: aoliva@redhat.com
> 
> Kyle - can you resend wit an updated changelog reflecting the comments
> from Roland and Alexandre.
> 
> I got it wrong when reading the above - so chances are others does too.
> 

Yes, certainly. My apologies, I let my frustration leak through a little
into the changelog. :)

regards, Kyle