linux-kernel - Re: linux-next: build warnings after merge of the kbuild tree

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Message-ID: <20160819133854.17a7b1ca@canb.auug.org.au>
Date:   Fri, 19 Aug 2016 13:38:54 +1000
From:   Stephen Rothwell <sfr@...b.auug.org.au>
To:     Nicholas Piggin <npiggin@...il.com>
Cc:     Michal Marek <mmarek@...e.cz>, linux-kernel@...r.kernel.org,
        linux-next@...r.kernel.org, Al Viro <viro@...iv.linux.org.uk>,
        PowerPC <linuxppc-dev@...ts.ozlabs.org>
Subject: Re: linux-next: build warnings after merge of the kbuild tree

Hi Nick,

On Thu, 18 Aug 2016 11:09:48 +1000 Nicholas Piggin <npiggin@...il.com> wrote:
>
> On Wed, 17 Aug 2016 14:59:59 +0200
> Michal Marek <mmarek@...e.cz> wrote:
> 
> > On 2016-08-17 03:44, Stephen Rothwell wrote:  
> > > 
> > > After merging the kbuild tree, today's linux-next build (powerpc
> > > ppc64_defconfig) produced these warnings:
> > > 
> > > WARNING: 25 bad relocations
> > > c000000000cf2570 R_PPC64_ADDR64    __crc___arch_hweight16    
> > [...]  
> > > Introduced by commit
> > > 
> > >   9445aa1a3062 ("ppc: move exports to definitions")
> > > 
> > > I have reverted that commit for today.
> > > 
> > > [cc-ing the ppc guys for clues - also involved is commit
> > > 
> > >   22823ab419d8 ("EXPORT_SYMBOL() for asm")
> > > ]    
> > 
> > FWIW, I see these warnings as well. Any help from ppc developers is
> > appreciated - should the R_PPC64_ADDR64 be whitelisted for exported asm
> > symbols (their CRCs actually)?  
> 
> The dangling relocation is a side effect of linker unable to resolve the
> reference to the undefined weak symbols. So the real question is, why has
> genksyms not overridden these symbols with their CRC values?
> 
> This may not even be powerpc specific, but  I'll poke at it a bit more
> when I get a chance.

Not sure if this is relevant, but with the commit reverted, the
__crc___... symbols are absolute.

00000000f55b3b3d A __crc___arch_hweight16

-- 
Cheers,
Stephen Rothwell