From mboxrd@z Thu Jan  1 00:00:00 1970
From: Nicholas Piggin <npiggin@gmail.com>
Subject: Re: linux-next: Tree for Dec 7 (kallsyms failure)
Date: Thu, 8 Dec 2016 15:07:51 +1000
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To: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Randy Dunlap <rdunlap@infradead.org>, linux-next@vger.kernel.org, linux-kernel@vger.kernel.org, Sachin Sant <sachinp@linux.vnet.ibm.com>, Michael Ellerman <mpe@ellerman.id.au>, Benjamin Herrenschmidt <benh@kernel.crashing.org>, PowerPC <linuxppc-dev@lists.ozlabs.org>, Ard Biesheuvel <ard.biesheuvel@linaro.org>, Balbir Singh <bsingharora@gmail.com>, Arnd Bergmann <arnd@arndb.de>, Linus <torvalds@linux-foundation.org>
List-Id: linux-next.vger.kernel.org

On Thu, 8 Dec 2016 15:29:35 +1100
Stephen Rothwell <sfr@canb.auug.org.au> wrote:

> Hi all,
> 
> On Wed, 7 Dec 2016 18:30:57 -0800 Randy Dunlap <rdunlap@infradead.org> wrote:
> >
> > On 12/07/16 15:56, Stephen Rothwell wrote:  
> > > 
> > > On Wed, 7 Dec 2016 15:42:32 -0800 Randy Dunlap <rdunlap@infradead.org> wrote:    
> > >>
> > >> I started seeing this yesterday (2016-1206).
> > >> This is on x86_64.
> > >>
> > >> Anybody know about it?
> > >>
> > >> kallsyms failure: relative symbol value 0xffffffff81000000 out of range in relative mode    
> > > 
> > > I got a similar failure starting a few days ago on my powerpc
> > > allyesconfig build.  I was assuming that it was PowerPC specific, but
> > > noone has found a cause yet.
> > >     
> > 
> > It may just be an invalid randconfig.  I modified scripts/kallsyms.c and
> > I see this message:
> > kallsyms failure: relative symbol value 0xffffffff81000000 [symbol: Tstartup_64] out of range in relative mode
> > 
> > and it makes sense that startup_64 would (or could) be at 0xffffffff81000000...
> > especially since CONFIG_PHYSICAL_START=0x1000000 and
> > (from Documentation/x86/x86_64/mm.txt)
> > ffffffff80000000 - ffffffff9fffffff (=512 MB)  kernel text mapping, from phys 0
> > 
> > 
> > Ard, what do you think about this?  
> 
> The similar failure I saw in the powerpc allyesconfig build
> 
> kallsyms failure: relative symbol value 0xc000000000000000 out of range in relative mode
> 
> was caused by commit
> 
>   8ab2ae655bfe ("default exported asm symbols to zero")
> 
> which has been reverted in Linus' tree today.
> 

Huh, so it seems like the explicit 0 symbols were being picked up as the
kallsyms relative base, putting the 0xc... symbols beyond reach.