On 5/1/22 3:00 PM, Yonghong Song wrote:
> The kflag is supported now for BTF_KIND_ENUM.
> So remove the test which tests verifier failure
> due to existence of kflag.
>
> With enum64 support in kernel and libbpf,
> selftest btf_dump/btf_dump failed with
> no-enum64 support llvm for the following
> enum definition:
> enum e2 {
> C = 100,
> D = 4294967295,
> E = 0,
> };
>
> With the no-enum64 support llvm, the signedness is
> 'signed' by default, and D (4294967295 = 0xffffffff)
> will print as -1. With enum64 support llvm, the signedness
> is 'unsigned' and the value of D will print as 4294967295.
To confirm my understanding, this signedness-by-default change is for _printing
btf in c format only_ and doesn't correspond to any difference in interpretation
, since all BTF enums before addition of new kflag were assumed to be signed,
and new kflag's default value is signed as well.
> To support both old and new compilers, this patch
> changed the value to 268435455 = 0xfffffff which works
> with both enum64 or non-enum64 support llvm.
>
> Signed-off-by: Yonghong Song <yhs@xxxxxx>
> ---
Aside from the general question, for changes in this patch:
Acked-by: Dave Marchevsky <davemarchevsky@xxxxxx>
