Re: [REGRESSION] mainline/master: (build) in arch/arm/kernel/entry-common.o (/tmp/kci/linux/scripts/Makefile...

[Nathan Chancellor <nathan@kernel.org>]

On Tue, Aug 18, 2026 at 09:51:21AM -0700, Nathan Chancellor wrote:
> On Tue, Aug 18, 2026 at 09:19:04AM -0700, Nick Desaulniers wrote:
> > + Ard
> > 
> > On Mon, Aug 17, 2026 at 11:00 PM Thorsten Leemhuis
> > <regressions@leemhuis.info> wrote:
> > > Nathan, Nick, do you still care about clang problems like this?
> > 
> > Yes, from the logs, it looks like ARCH=arm allmodconfig with clang-21
> > (perhaps, there's a funny warning about the compiler version in the
> > logs).
> > 
> > > And do
> > > you by chance know what's wrong here?
> > >
> > > """
> > > <instantiation>:2:11: error: out of range pc-relative fixup value
> > >  ldr r10, =__per_cpu_offset
> > >           ^
> > > <instantiation>:2:11: error: out of range pc-relative fixup value
> > >  ldr tsk, =__current
> > >           ^
> > > <instantiation>:2:11: error: out of range pc-relative fixup value
> > >  ldr tsk, =__current
> > >           ^
> > 
> > Smells like the same problem that was addressed by
> > commit 5fe41793bc78 ("ARM: 9176/1: avoid literal references in inline assembly")
> > 
> > What tree was being tested? 5fe41793bc78 landed in v5.18-rc1. Whatever
> > was being tested is probably missing that patch.
> 
> As Mark notes, this is mainline. This error is visible with LLVM 23 as
> well. I bisected it to commit 79d27fd71854 ("arch: hookup fchroot()
> system call").
> 
> I do see that change in -next and there is no error there so was this a
> known issue that was fixed in another tree? I will keep looking.

It looks like commit 25900bd99d4d ("ARM: limit OABI support to StrongARM
CPUs") in the soc tree avoids this error by disabling CONFIG_OABI_COMPAT
for allmodconfig. If I disable that on top of allmodconfig with current
mainline, the error goes away.

I narrowed down a reproducer to

  $ cat arch/arm/configs/repro.config
  CONFIG_ARCH_MULTI_V6=y
  CONFIG_ARCH_REALVIEW=y
  CONFIG_COMPILE_TEST=y
  CONFIG_MACH_REALVIEW_PB1176=y
  CONFIG_OABI_COMPAT=y

  $ make -skj"$(nproc)" ARCH=arm LLVM=1 mrproper defconfig repro.config arch/arm/kernel/entry-common.o
  <instantiation>:2:11: error: out of range pc-relative fixup value
   ldr r10, =__per_cpu_offset
            ^
  <instantiation>:2:11: error: out of range pc-relative fixup value
   ldr tsk, =__current
            ^
  <instantiation>:2:11: error: out of range pc-relative fixup value
   ldr tsk, =__current
            ^

CONFIG_COMPILE_TEST is necessary because it turns off
CONFIG_ARM_HAS_GROUP_RELOCS, which seems relevant here.

-- 
Cheers,
Nathan