Re: [PATCH bpf-next v2 2/3] bpf: btf: add btf print functionality

Jakub Kicinski
2018-07-03T22:38:53Z

On Tue, 3 Jul 2018 15:23:31 -0700, Jakub Kicinski wrote:
> > > > + else
> > > > + jsonw_printf(jw, "%hhd", *((char *)data));
> > >
> > > ... I think you need to always print a string, and express it as
> > > \u00%02hhx for non-printable.
> > Okay that makes sense
>
> Yeah, IDK, char can be used as a byte as well as a string. In eBPF
> it may actually be more likely to just be used as a raw byte buffer...

Actually, what is the definition/purpose of BTF_INT_CHAR? There seems
to be no BTF_INT_SHORT and BTF_INT_SIGNED can simply be of size 8...
Is normal int only used for bitfields of size 8 and BTF_INT_CHAR for
char variables?

The kernel seems to be rejecting combinations of those flags, is
unsigned char going to not be marked as char then?

> Either way I think it may be nice to keep it consistent, at least for
> the JSON output could we do either always ints or always characters?