On Wed, Feb 7, 2024 at 5:17 PM Andrii Nakryiko
<andrii.nakryiko@xxxxxxxxx> wrote:
>
> On Tue, Feb 6, 2024 at 2:05 PM Alexei Starovoitov
> <alexei.starovoitov@xxxxxxxxx> wrote:
> >
> > From: Alexei Starovoitov <ast@xxxxxxxxxx>
> >
> > __uint() macro that is used to specify map attributes like:
> > __uint(type, BPF_MAP_TYPE_ARRAY);
> > __uint(map_flags, BPF_F_MMAPABLE);
> > is limited to 32-bit, since BTF_KIND_ARRAY has u32 "number of elements" field.
> >
> > Introduce __ulong() macro that allows specifying values bigger than 32-bit.
> > In map definition "map_extra" is the only u64 field.
> >
> > Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
> > ---
> > tools/lib/bpf/bpf_helpers.h | 1 +
> > tools/lib/bpf/libbpf.c | 44 ++++++++++++++++++++++++++++++++++---
> > 2 files changed, 42 insertions(+), 3 deletions(-)
> >
> > diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h
> > index 9c777c21da28..fb909fc6866d 100644
> > --- a/tools/lib/bpf/bpf_helpers.h
> > +++ b/tools/lib/bpf/bpf_helpers.h
> > @@ -13,6 +13,7 @@
> > #define __uint(name, val) int (*name)[val]
> > #define __type(name, val) typeof(val) *name
> > #define __array(name, val) typeof(val) *name[]
> > +#define __ulong(name, val) enum name##__enum { name##__value = val } name
>
> Can you try using __ulong() twice in the same file? enum type and
> value names have global visibility, so I suspect second use with the
> same field name would cause compilation error
Good point will change it to:
#define __ulong(name, val) enum { __PASTE(__unique_value,__COUNTER__)
= val } name
