On Sun, May 1, 2022 at 12:00 PM Yonghong Song <yhs@xxxxxx> wrote:
>
> Add BTF_KIND_ENUM64 support.
> For example, the following enum is defined in uapi bpf.h.
> $ cat core.c
> enum A {
> BPF_F_INDEX_MASK = 0xffffffffULL,
> BPF_F_CURRENT_CPU = BPF_F_INDEX_MASK,
> BPF_F_CTXLEN_MASK = (0xfffffULL << 32),
> } g;
> Compiled with
> clang -target bpf -O2 -g -c core.c
> Using bpftool to dump types and generate format C file:
> $ bpftool btf dump file core.o
> ...
> [1] ENUM64 'A' size=8 vlen=3
> 'BPF_F_INDEX_MASK' val=4294967295ULL
> 'BPF_F_CURRENT_CPU' val=4294967295ULL
> 'BPF_F_CTXLEN_MASK' val=4503595332403200ULL
> $ bpftool btf dump file core.o format c
> ...
> enum A {
> BPF_F_INDEX_MASK = 4294967295ULL,
> BPF_F_CURRENT_CPU = 4294967295ULL,
> BPF_F_CTXLEN_MASK = 4503595332403200ULL,
maybe we should have some heuristic that if the value is "big enough"
(e.g., larger than 1-128 millions) and is unsigned we should emit it
as hex?
> };
> ...
>
> The 64bit value is represented properly in BTF and C dump.
>
> Signed-off-by: Yonghong Song <yhs@xxxxxx>
> ---
just minor nits, LGTM
Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
> tools/bpf/bpftool/btf.c | 47 ++++++++++++++++++++++++++++++++--
> tools/bpf/bpftool/btf_dumper.c | 32 +++++++++++++++++++++++
> tools/bpf/bpftool/gen.c | 1 +
> 3 files changed, 78 insertions(+), 2 deletions(-)
>
[...]
> + case BTF_KIND_ENUM64: {
> + const struct btf_enum64 *v = (const void *)(t + 1);
can use btf_enum64() helper from libbpf?
> + __u16 vlen = BTF_INFO_VLEN(t->info);
btf_vlen(t)
> + int i;
> +
> + if (json_output) {
> + jsonw_uint_field(w, "size", t->size);
> + jsonw_uint_field(w, "vlen", vlen);
> + jsonw_name(w, "values");
> + jsonw_start_array(w);
> + } else {
> + printf(" size=%u vlen=%u", t->size, vlen);
> + }
> + for (i = 0; i < vlen; i++, v++) {
> + const char *name = btf_str(btf, v->name_off);
> + __u64 val = (__u64)v->hi32 << 32 | v->lo32;
() ?
> +
> + if (json_output) {
> + jsonw_start_object(w);
> + jsonw_string_field(w, "name", name);
> + if (btf_kflag(t))
> + jsonw_uint_field(w, "val", val);
> + else
> + jsonw_int_field(w, "val", val);
> + jsonw_end_object(w);
> + } else {
> + if (btf_kflag(t))
> + printf("\n\t'%s' val=%lluULL", name, val);
> + else
> + printf("\n\t'%s' val=%lldLL", name, val);
> }
> }
> if (json_output)
> diff --git a/tools/bpf/bpftool/btf_dumper.c b/tools/bpf/bpftool/btf_dumper.c
> index f5dddf8ef404..f9f38384b9a6 100644
> --- a/tools/bpf/bpftool/btf_dumper.c
> +++ b/tools/bpf/bpftool/btf_dumper.c
> @@ -182,6 +182,35 @@ static int btf_dumper_enum(const struct btf_dumper *d,
> return 0;
> }
>
> +static int btf_dumper_enum64(const struct btf_dumper *d,
> + const struct btf_type *t,
> + const void *data)
> +{
> + const struct btf_enum64 *enums = btf_enum64(t);
> + __u32 hi32, lo32;
> + __u64 value;
> + __u16 i;
> +
> + if (t->size != 8)
> + return -EINVAL;
no need
> +
> + value = *(__u64 *)data;
> + hi32 = value >> 32;
> + lo32 = (__u32)value;
> +
[...]
