Re: net/netfilter/nf_bpf_link.c:186:33: warning: bitwise operation between different enumeration types ('enum bpf_reg_type' and 'enum bpf_type_flag')

[Nathan Chancellor <nathan@kernel.org>]

Hi all,

On Fri, Mar 01, 2024 at 08:57:56AM +0800, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   87adedeba51a822533649b143232418b9e26d08b
> commit: fd9c663b9ad67dedfc9a3fd3429ddd3e83782b4d bpf: minimal support for programs hooked into netfilter framework
> date:   10 months ago
> config: riscv-defconfig (https://download.01.org/0day-ci/archive/20240301/202403010842.hhJY5TFK-lkp@intel.com/config)
> compiler: clang version 19.0.0git (https://github.com/llvm/llvm-project edd4aee4dd9b5b98b2576a6f783e4086173d902a)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240301/202403010842.hhJY5TFK-lkp@intel.com/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@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202403010842.hhJY5TFK-lkp@intel.com/
> 
> All warnings (new ones prefixed by >>):

<snip>

While this change may introduce an instance of this warning, it is
actually a change on the clang side that causes this and I am still
looking for input on what to do about it:

https://github.com/ClangBuiltLinux/linux/issues/2002

I think this report can just be ignored for now. The Intel folks may
want to consider sending -Wenum-enum-conversion and
-Wenum-compare-conditional reports to our mailing list only until we can
sort this out. Sorry for the noise.

Cheers,
Nathan

> >> net/netfilter/nf_bpf_link.c:186:33: warning: bitwise operation between different enumeration types ('enum bpf_reg_type' and 'enum bpf_type_flag') [-Wenum-enum-conversion]
>      186 |         info->reg_type = PTR_TO_BTF_ID | PTR_TRUSTED;
>          |                          ~~~~~~~~~~~~~ ^ ~~~~~~~~~~~
>    22 warnings generated.
> 
> 
> vim +186 net/netfilter/nf_bpf_link.c
> 
>    170	
>    171	static bool nf_ptr_to_btf_id(struct bpf_insn_access_aux *info, const char *name)
>    172	{
>    173		struct btf *btf;
>    174		s32 type_id;
>    175	
>    176		btf = bpf_get_btf_vmlinux();
>    177		if (IS_ERR_OR_NULL(btf))
>    178			return false;
>    179	
>    180		type_id = btf_find_by_name_kind(btf, name, BTF_KIND_STRUCT);
>    181		if (WARN_ON_ONCE(type_id < 0))
>    182			return false;
>    183	
>    184		info->btf = btf;
>    185		info->btf_id = type_id;
>  > 186		info->reg_type = PTR_TO_BTF_ID | PTR_TRUSTED;
>    187		return true;
>    188	}
>    189	
> 
> -- 
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki
>