Re: [linux-next:master 5519/11156] kernel/bpf/bpf_struct_ops.c:247:16: warning: bitwise operation between different enumeration types ('enum bpf_type_flag' and 'enum bpf_reg_type')

[Yonghong Song <yonghong.song@linux.dev>]

On 3/1/24 10:27 AM, Alexei Starovoitov wrote:
> On Fri, Mar 1, 2024 at 10:26 AM Kui-Feng Lee <sinquersw@gmail.com> wrote:
>> For BPF,
>>
>> We have a lot of code mixing bpf_type_flag and bpf_reg_type in bpf.
>> They cause the warning messages described in the message following.
>> Do we want to fix them all, or keep them as they are?
>>
>> They can be fixed by merging two enum types or casting here and there if
>> we want. Any other idea?
> We probably should add -Wno-enum-enum-conversion to kernel/bpf/Makefile instead.

The warnings are only triggered with latest llvm19 development branch.
The warnings are triggered in many subsystems, bpf, mm, etc.
The following commandline can workaround the issue:
    make LLVM=1 -j KCFLAGS=-Wno-enum-enum-conversion
There is a discussion how to fix it here:
   https://github.com/ClangBuiltLinux/linux/issues/2002
No conclusion yet.