On Thu, May 26, 2022 at 11:55 AM Yonghong Song <yhs@xxxxxx> wrote:
>
> The enum64 relocation support is added. The bpf local type
> could be either enum or enum64 and the remote type could be
> either enum or enum64 too. The all combinations of local enum/enum64
> and remote enum/enum64 are supported.
>
> Signed-off-by: Yonghong Song <yhs@xxxxxx>
> ---
> tools/lib/bpf/btf.h | 7 +++++
> tools/lib/bpf/libbpf.c | 7 ++---
> tools/lib/bpf/relo_core.c | 54 +++++++++++++++++++++++++++------------
> 3 files changed, 48 insertions(+), 20 deletions(-)
>
[...]
> local_essent_len = bpf_core_essential_name_len(local_acc->name);
>
> - for (i = 0, e = btf_enum(targ_type); i < btf_vlen(targ_type); i++, e++) {
> - targ_name = btf__name_by_offset(targ_spec->btf, e->name_off);
> + for (i = 0; i < btf_vlen(targ_type); i++) {
> + if (btf_is_enum(targ_type))
> + name_off = btf_enum(targ_type)[i].name_off;
> + else
> + name_off = btf_enum64(targ_type)[i].name_off;
> +
> + targ_name = btf__name_by_offset(targ_spec->btf, name_off);
> targ_essent_len = bpf_core_essential_name_len(targ_name);
> if (targ_essent_len != local_essent_len)
> continue;
> @@ -680,8 +688,7 @@ static int bpf_core_calc_field_relo(const char *prog_name,
> *val = byte_sz;
> break;
> case BPF_CORE_FIELD_SIGNED:
> - /* enums will be assumed unsigned */
> - *val = btf_is_enum(mt) ||
> + *val = btf_type_is_any_enum(mt) ||
wouldn't this be more correct with kflag meaning "signed":
(btf_type_is_any_enum(mt) && btf_kflag(mt)) ||
?
> (btf_int_encoding(mt) & BTF_INT_SIGNED);
> if (validate)
> *validate = true; /* signedness is never ambiguous */
> @@ -754,7 +761,6 @@ static int bpf_core_calc_enumval_relo(const struct bpf_core_relo *relo,
> __u64 *val)
> {
> const struct btf_type *t;
> - const struct btf_enum *e;
>
> switch (relo->kind) {
> case BPF_CORE_ENUMVAL_EXISTS:
> @@ -764,8 +770,10 @@ static int bpf_core_calc_enumval_relo(const struct bpf_core_relo *relo,
> if (!spec)
> return -EUCLEAN; /* request instruction poisoning */
> t = btf_type_by_id(spec->btf, spec->spec[0].type_id);
> - e = btf_enum(t) + spec->spec[0].idx;
> - *val = e->val;
> + if (btf_is_enum(t))
> + *val = btf_enum(t)[spec->spec[0].idx].val;
> + else
> + *val = btf_enum64_value(btf_enum64(t) + spec->spec[0].idx);
> break;
> default:
> return -EOPNOTSUPP;
> @@ -1060,7 +1068,6 @@ int bpf_core_patch_insn(const char *prog_name, struct bpf_insn *insn,
> int bpf_core_format_spec(char *buf, size_t buf_sz, const struct bpf_core_spec *spec)
> {
> const struct btf_type *t;
> - const struct btf_enum *e;
> const char *s;
> __u32 type_id;
> int i, len = 0;
> @@ -1089,10 +1096,23 @@ int bpf_core_format_spec(char *buf, size_t buf_sz, const struct bpf_core_spec *s
>
> if (core_relo_is_enumval_based(spec->relo_kind)) {
> t = skip_mods_and_typedefs(spec->btf, type_id, NULL);
> - e = btf_enum(t) + spec->raw_spec[0];
> - s = btf__name_by_offset(spec->btf, e->name_off);
> + if (btf_is_enum(t)) {
> + const struct btf_enum *e;
> + const char *fmt_str;
> +
> + e = btf_enum(t) + spec->raw_spec[0];
> + s = btf__name_by_offset(spec->btf, e->name_off);
> + fmt_str = BTF_INFO_KFLAG(t->info) ? "::%s = %d" : "::%s = %u";
minor nit: btf_kflag(t) instead of BTF_INFO_KFLAGS(t->info)?
> + append_buf(fmt_str, s, e->val);
> + } else {
> + const struct btf_enum64 *e;
> + const char *fmt_str;
>
> - append_buf("::%s = %u", s, e->val);
> + e = btf_enum64(t) + spec->raw_spec[0];
> + s = btf__name_by_offset(spec->btf, e->name_off);
> + fmt_str = BTF_INFO_KFLAG(t->info) ? "::%s = %lld" : "::%s = %llu";
> + append_buf(fmt_str, s, (unsigned long long)btf_enum64_value(e));
> + }
> return len;
> }
>
> --
> 2.30.2
>
