[PATCH bpf-next 05/12] bpftool: Add btf enum64 support

[Yonghong Song <yhs@xxxxxx>]

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,
  };
  ...

The 64bit value is represented properly in BTF and C dump.

Signed-off-by: Yonghong Song <yhs@xxxxxx>
---
 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(-)

diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c
index a2c665beda87..ae3c413fa3b1 100644
--- a/tools/bpf/bpftool/btf.c
+++ b/tools/bpf/bpftool/btf.c
@@ -40,6 +40,7 @@ static const char * const btf_kind_str[NR_BTF_KINDS] = {
 	[BTF_KIND_FLOAT]	= "FLOAT",
 	[BTF_KIND_DECL_TAG]	= "DECL_TAG",
 	[BTF_KIND_TYPE_TAG]	= "TYPE_TAG",
+	[BTF_KIND_ENUM64]	= "ENUM64",
 };
 
 struct btf_attach_point {
@@ -228,10 +229,52 @@ static int dump_btf_type(const struct btf *btf, __u32 id,
 			if (json_output) {
 				jsonw_start_object(w);
 				jsonw_string_field(w, "name", name);
-				jsonw_uint_field(w, "val", v->val);
+				if (btf_kflag(t))
+					jsonw_uint_field(w, "val", v->val);
+				else
+					jsonw_int_field(w, "val", v->val);
 				jsonw_end_object(w);
 			} else {
-				printf("\n\t'%s' val=%u", name, v->val);
+				if (btf_kflag(t))
+					printf("\n\t'%s' val=%u", name, v->val);
+				else
+					printf("\n\t'%s' val=%d", name, v->val);
+			}
+		}
+		if (json_output)
+			jsonw_end_array(w);
+		break;
+	}
+	case BTF_KIND_ENUM64: {
+		const struct btf_enum64 *v = (const void *)(t + 1);
+		__u16 vlen = BTF_INFO_VLEN(t->info);
+		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;
+
+	value = *(__u64 *)data;
+	hi32 = value >> 32;
+	lo32 = (__u32)value;
+
+	for (i = 0; i < btf_vlen(t); i++) {
+		if (hi32 == enums[i].hi32 && lo32 == enums[i].lo32) {
+			jsonw_string(d->jw,
+				     btf__name_by_offset(d->btf,
+							 enums[i].name_off));
+			return 0;
+		}
+	}
+
+	jsonw_int(d->jw, value);
+	return 0;
+}
+
 static bool is_str_array(const struct btf *btf, const struct btf_array *arr,
 			 const char *s)
 {
@@ -542,6 +571,8 @@ static int btf_dumper_do_type(const struct btf_dumper *d, __u32 type_id,
 		return btf_dumper_array(d, type_id, data);
 	case BTF_KIND_ENUM:
 		return btf_dumper_enum(d, t, data);
+	case BTF_KIND_ENUM64:
+		return btf_dumper_enum64(d, t, data);
 	case BTF_KIND_PTR:
 		btf_dumper_ptr(d, t, data);
 		return 0;
@@ -618,6 +649,7 @@ static int __btf_dumper_type_only(const struct btf *btf, __u32 type_id,
 			      btf__name_by_offset(btf, t->name_off));
 		break;
 	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64:
 		BTF_PRINT_ARG("enum %s ",
 			      btf__name_by_offset(btf, t->name_off));
 		break;
diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c
index 7678af364793..b80c3577057f 100644
--- a/tools/bpf/bpftool/gen.c
+++ b/tools/bpf/bpftool/gen.c
@@ -1746,6 +1746,7 @@ btfgen_mark_type(struct btfgen_info *info, unsigned int type_id, bool follow_poi
 	case BTF_KIND_INT:
 	case BTF_KIND_FLOAT:
 	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64:
 	case BTF_KIND_STRUCT:
 	case BTF_KIND_UNION:
 		break;
-- 
2.30.2