Re: WARNING: modpost: vmlinux.o(.text+0x74fea4): Section mismatch in reference from the function memblock_find_in_range_node() to the function .init.text:memblock_bottom_up()

From: Mike Rapoport
Date: Tue Mar 16 2021 - 03:05:13 EST


On Tue, Mar 16, 2021 at 01:23:08AM +0800, kernel test robot wrote:
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head: 1e28eed17697bcf343c6743f0028cc3b5dd88bf0
> commit: 34dc2efb39a231280fd6696a59bbe712bf3c5c4a memblock: fix section mismatch warning
> date: 2 days ago
> config: arm64-randconfig-r013-20210315 (attached as .config)
> compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project a28facba1ccdc957f386b7753f4958307f1bfde8)
> 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 arm64 cross compiling tool for clang build
> # apt-get install binutils-aarch64-linux-gnu
> # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=34dc2efb39a231280fd6696a59bbe712bf3c5c4a
> git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> git fetch --no-tags linus master
> git checkout 34dc2efb39a231280fd6696a59bbe712bf3c5c4a
> # save the attached .config to linux build tree
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
>
> All warnings (new ones prefixed by >>, old ones prefixed by <<):
>
> >> WARNING: modpost: vmlinux.o(.text+0x74fea4): Section mismatch in reference from the function memblock_find_in_range_node() to the function .init.text:memblock_bottom_up()
> The function memblock_find_in_range_node() references
> the function __init memblock_bottom_up().
> This is often because memblock_find_in_range_node lacks a __init
> annotation or the annotation of memblock_bottom_up is wrong.

I don't have clang-13 setup handy so I could not check, but I think this
should be the fix:

diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index d13e3cd938b4..5984fff3f175 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -460,7 +460,7 @@ static inline void memblock_free_late(phys_addr_t base, phys_addr_t size)
/*
* Set the allocation direction to bottom-up or top-down.
*/
-static inline __init void memblock_set_bottom_up(bool enable)
+static inline __init_memblock void memblock_set_bottom_up(bool enable)
{
memblock.bottom_up = enable;
}
@@ -470,7 +470,7 @@ static inline __init void memblock_set_bottom_up(bool enable)
* if this is true, that said, memblock will allocate memory
* in bottom-up direction.
*/
-static inline __init bool memblock_bottom_up(void)
+static inline __init_memblock bool memblock_bottom_up(void)
{
return memblock.bottom_up;
}


--
Sincerely yours,
Mike.