Re: WARNING: modpost: vmlinux: section mismatch in reference: bitmap_gather+0x68 (section: .text) -> sg_mask (section: .init.rodata)

From: Andy Shevchenko
Date: Wed Aug 14 2024 - 12:32:17 EST


+Cc: Clang and bitmap people.

On Thu, Jun 20, 2024 at 08:54:29AM +0800, kernel test robot wrote:
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head: e5b3efbe1ab1793bb49ae07d56d0973267e65112
> commit: de5f84338970815b9fdd3497a975fb572d11e0b5 lib/bitmap: Introduce bitmap_scatter() and bitmap_gather() helpers
> date: 3 months ago
> config: um-randconfig-r123-20240620 (https://download.01.org/0day-ci/archive/20240620/202406200829.IytwLyQJ-lkp@xxxxxxxxx/config)
> compiler: clang version 19.0.0git (https://github.com/llvm/llvm-project 78ee473784e5ef6f0b19ce4cb111fb6e4d23c6b2)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240620/202406200829.IytwLyQJ-lkp@xxxxxxxxx/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202406200829.IytwLyQJ-lkp@xxxxxxxxx/
>
> All warnings (new ones prefixed by >>, old ones prefixed by <<):
>
> WARNING: modpost: missing MODULE_DESCRIPTION() in vmlinux.o
> >> WARNING: modpost: vmlinux: section mismatch in reference: bitmap_gather+0x68 (section: .text) -> sg_mask (section: .init.rodata)
> WARNING: modpost: vmlinux: section mismatch in reference: bitmap_gather+0x10b (section: .text) -> sg_mask (section: .init.rodata)
> >> WARNING: modpost: vmlinux: section mismatch in reference: bitmap_scatter+0x68 (section: .text) -> sg_mask (section: .init.rodata)
> WARNING: modpost: vmlinux: section mismatch in reference: bitmap_scatter+0x119 (section: .text) -> sg_mask (section: .init.rodata)

I have no other idea that this is a (yet another) clang compiler bug related to
the constant data.

--
With Best Regards,
Andy Shevchenko