RE: [PATCH bpf-next 2/6] libbpf: Add BTF_KIND_FLOAT support

[John Fastabend <john.fastabend@gmail.com>]

John Fastabend wrote:
> Ilya Leoshkevich wrote:
> > The logic follows that of BTF_KIND_INT most of the time. Sanitization
> > replaces BTF_KIND_FLOATs with equally-sized BTF_KIND_INTs on older
>                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
> Does this match the code though?
> 
> > kernels.
> > 
> > Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
> > ---
> 
> [...]
> 
> 
> > @@ -2445,6 +2450,9 @@ static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf)
> >  		} else if (!has_func_global && btf_is_func(t)) {
> >  			/* replace BTF_FUNC_GLOBAL with BTF_FUNC_STATIC */
> >  			t->info = BTF_INFO_ENC(BTF_KIND_FUNC, 0, 0);
> > +		} else if (!has_float && btf_is_float(t)) {
> > +			/* replace FLOAT with INT */
> > +			t->info = BTF_INFO_ENC(BTF_KIND_FLOAT, 0, 0);
> 
> Do we also need to encode the vlen here?

Sorry typo on my side, 't->size = ?' is what I was trying to point out.
Looks like its set in the other case where we replace VAR with INT.

> 
> #define BTF_INFO_ENC(kind, kind_flag, vlen) \
> 	((!!(kind_flag) << 31) | ((kind) << 24) | ((vlen) & BTF_MAX_VLEN))
> 
> >  		}
> >  	}
> >  }
> > @@ -3882,6 +3890,18 @@ static int probe_kern_btf_datasec(void)
> >  					     strs, sizeof(strs)));
> >  }