btf_loader: Add support to BTF_KIND_ENUM64

It'll just reuse 'struct enumerator' and 'struct enumeration', as
'enumerator' already suppored 64-bit due to DWARF.

  $ pdwtags -F btf vmlinux-v5.18-rc7+ | grep -B5 -A5 BPF_F_CTXLEN_MASK

  /* 27413 */
  enum {
          BPF_F_INDEX_MASK  = 4294967295,
          BPF_F_CURRENT_CPU = 4294967295,
          BPF_F_CTXLEN_MASK = 4503595332403200,
  } __attribute__((__packed__)); /* size: 8 */

  /* 27414 */
  enum {
          BPF_F_GET_BRANCH_RECORDS_SIZE = 1,
  $

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: bpf@vger.kernel.org
Cc: kernel-team@fb.com
Link: https://lore.kernel.org/dwarves/YryELT6OadpiJki%2F@kernel.org/
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 46 insertions, 0 deletions

diff --git a/btf_loader.c b/btf_loader.c
index b5d44464..406a007b 100644
--- a/btf_loader.c
+++ b/btf_loader.c
@@ -312,6 +312,49 @@ out_free:
 	return -ENOMEM;
 }
 
+static struct enumerator *enumerator__new64(const char *name, uint64_t value)
+{
+	struct enumerator *en = tag__alloc(sizeof(*en));
+
+	if (en != NULL) {
+		en->name = name;
+		en->value = value; // Value is already 64-bit, as this is used with DWARF as well
+		en->tag.tag = DW_TAG_enumerator;
+	}
+
+	return en;
+}
+
+static int create_new_enumeration64(struct cu *cu, const struct btf_type *tp, uint32_t id)
+{
+	struct btf_enum64 *ep = btf_enum64(tp);
+	uint16_t i, vlen = btf_vlen(tp);
+	struct type *enumeration = type__new(DW_TAG_enumeration_type,
+					     cu__btf_str(cu, tp->name_off),
+					     tp->size ? tp->size * 8 : (sizeof(int) * 8));
+
+	if (enumeration == NULL)
+		return -ENOMEM;
+
+	for (i = 0; i < vlen; i++) {
+		const char *name = cu__btf_str(cu, ep[i].name_off);
+		uint64_t value = btf_enum64_value(&ep[i]);
+		struct enumerator *enumerator = enumerator__new64(name, value);
+
+		if (enumerator == NULL)
+			goto out_free;
+
+		enumeration__add(enumeration, enumerator);
+	}
+
+	cu__add_tag_with_id(cu, &enumeration->namespace.tag, id);
+
+	return 0;
+out_free:
+	enumeration__delete(enumeration);
+	return -ENOMEM;
+}
+
 static int create_new_subroutine_type(struct cu *cu, const struct btf_type *tp, uint32_t id)
 {
 	struct ftype *proto = tag__alloc(sizeof(*proto));
@@ -419,6 +462,9 @@ static int btf__load_types(struct btf *btf, struct cu *cu)
 		case BTF_KIND_ENUM:
 			err = create_new_enumeration(cu, type_ptr, type_index);
 			break;
+		case BTF_KIND_ENUM64:
+			err = create_new_enumeration64(cu, type_ptr, type_index);
+			break;
 		case BTF_KIND_FWD:
 			err = create_new_forward_decl(cu, type_ptr, type_index);
 			break;