Re: [stable:linux-5.10.y 2705/5321] WARNING: modpost: vmlinux.o(.text+0x8cc4): Section mismatch in reference from the function __arm_ioremap_pfn_caller() to the function .meminit.text:memblock_is_map_memory()

[Mike Rapoport <rppt@linux.ibm.com>]

On Fri, Apr 22, 2022 at 07:37:19AM +0800, kernel test robot wrote:
> Hi Mike,
> 
> FYI, the error/warning still remains.
> 
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git linux-5.10.y
> head:   1052f9bce62982023737a95b7ff1ad26a5149af6
> commit: 8dd559d53b3b2de960ca1ec1359f5a9b4a12e181 [2705/5321] arm: ioremap: don't abuse pfn_valid() to check if pfn is in RAM
> config: arm-hackkit_defconfig (https://download.01.org/0day-ci/archive/20220422/202204220723.zOZ7gZGT-lkp@intel.com/config)
> compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 5bd87350a5ae429baf8f373cb226a57b62f87280)
> reproduce (this is a W=1 build):
>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # install arm cross compiling tool for clang build
>         # apt-get install binutils-arm-linux-gnueabi
>         # https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit/?id=8dd559d53b3b2de960ca1ec1359f5a9b4a12e181
>         git remote add stable https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git
>         git fetch --no-tags stable linux-5.10.y
>         git checkout 8dd559d53b3b2de960ca1ec1359f5a9b4a12e181
>         # save the config file
>         mkdir build_dir && cp config build_dir/.config
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
> 
> All warnings (new ones prefixed by >>, old ones prefixed by <<):
> 
> >> WARNING: modpost: vmlinux.o(.text+0x8cc4): Section mismatch in reference from the function __arm_ioremap_pfn_caller() to the function .meminit.text:memblock_is_map_memory()
> The function __arm_ioremap_pfn_caller() references
> the function __meminit memblock_is_map_memory().
> This is often because __arm_ioremap_pfn_caller lacks a __meminit
> annotation or the annotation of memblock_is_map_memory is wrong.

In 5.10 the hackkit defconfig does not select ARCH_KEEP_MEMBLOCK which is
required for memblock_is_map_memory() to function after boot.

In upstream kernels ARCH_KEEP_MEMBLOCK is always selected by ARM after
commit 5e545df3292f ("arm: remove CONFIG_ARCH_HAS_HOLES_MEMORYMODEL")

So the fix would be either to backport 5e545df3292f or unconditionally
select ARCH_KEEP_MEMBLOCK on ARM in 5.10.

(the same applies to 5.4)

Greg, what is your preference?
 
> -- 
> 0-DAY CI Kernel Test Service
> https://01.org/lkp

-- 
Sincerely yours,
Mike.