libbpf: Add enum64 support for btf_dump

Add enum64 btf dumping support. For long long and unsigned long long
dump, suffixes 'LL' and 'ULL' are added to avoid compilation errors
in some cases.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20220607062631.3720526-1-yhs@fb.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

tools/lib/bpf/btf.h

@@ -566,6 +566,11 @@ static inline struct btf_enum64 *btf_enum64(const struct btf_type *t)
 	return (struct btf_enum64 *)(t + 1);
 }
 
+static inline __u64 btf_enum64_value(const struct btf_enum64 *e)
+{
+	return ((__u64)e->val_hi32 << 32) | e->val_lo32;
+}
+
 static inline struct btf_member *btf_members(const struct btf_type *t)
 {
 	return (struct btf_member *)(t + 1);

tools/lib/bpf/btf_dump.c

@@ -318,6 +318,7 @@ static int btf_dump_mark_referenced(struct btf_dump *d)
 		switch (btf_kind(t)) {
 		case BTF_KIND_INT:
 		case BTF_KIND_ENUM:
+		case BTF_KIND_ENUM64:
 		case BTF_KIND_FWD:
 		case BTF_KIND_FLOAT:
 			break;
@@ -538,6 +539,7 @@ static int btf_dump_order_type(struct btf_dump *d, __u32 id, bool through_ptr)
 		return 1;
 	}
 	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64:
 	case BTF_KIND_FWD:
 		/*
 		 * non-anonymous or non-referenced enums are top-level
@@ -739,6 +741,7 @@ static void btf_dump_emit_type(struct btf_dump *d, __u32 id, __u32 cont_id)
 		tstate->emit_state = EMITTED;
 		break;
 	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64:
 		if (top_level_def) {
 			btf_dump_emit_enum_def(d, id, t, 0);
 			btf_dump_printf(d, ";\n\n");
@@ -989,38 +992,81 @@ static void btf_dump_emit_enum_fwd(struct btf_dump *d, __u32 id,
 	btf_dump_printf(d, "enum %s", btf_dump_type_name(d, id));
 }
 
-static void btf_dump_emit_enum_def(struct btf_dump *d, __u32 id,
+static void btf_dump_emit_enum32_val(struct btf_dump *d,
 				     const struct btf_type *t,
-				   int lvl)
+				     int lvl, __u16 vlen)
 {
 	const struct btf_enum *v = btf_enum(t);
-	__u16 vlen = btf_vlen(t);
+	bool is_signed = btf_kflag(t);
+	const char *fmt_str;
 	const char *name;
 	size_t dup_cnt;
 	int i;
 
-	btf_dump_printf(d, "enum%s%s",
-			t->name_off ? " " : "",
-			btf_dump_type_name(d, id));
-
-	if (vlen) {
-		btf_dump_printf(d, " {");
 	for (i = 0; i < vlen; i++, v++) {
 		name = btf_name_of(d, v->name_off);
 		/* enumerators share namespace with typedef idents */
 		dup_cnt = btf_dump_name_dups(d, d->ident_names, name);
 		if (dup_cnt > 1) {
-				btf_dump_printf(d, "\n%s%s___%zu = %u,",
+			fmt_str = is_signed ? "\n%s%s___%zd = %d," : "\n%s%s___%zd = %u,";
+			btf_dump_printf(d, fmt_str, pfx(lvl + 1), name, dup_cnt, v->val);
+		} else {
+			fmt_str = is_signed ? "\n%s%s = %d," : "\n%s%s = %u,";
+			btf_dump_printf(d, fmt_str, pfx(lvl + 1), name, v->val);
+		}
+	}
+}
+
+static void btf_dump_emit_enum64_val(struct btf_dump *d,
+				     const struct btf_type *t,
+				     int lvl, __u16 vlen)
+{
+	const struct btf_enum64 *v = btf_enum64(t);
+	bool is_signed = btf_kflag(t);
+	const char *fmt_str;
+	const char *name;
+	size_t dup_cnt;
+	__u64 val;
+	int i;
+
+	for (i = 0; i < vlen; i++, v++) {
+		name = btf_name_of(d, v->name_off);
+		dup_cnt = btf_dump_name_dups(d, d->ident_names, name);
+		val = btf_enum64_value(v);
+		if (dup_cnt > 1) {
+			fmt_str = is_signed ? "\n%s%s___%zd = %lldLL,"
+					    : "\n%s%s___%zd = %lluULL,";
+			btf_dump_printf(d, fmt_str,
 					pfx(lvl + 1), name, dup_cnt,
-						(__u32)v->val);
+					(unsigned long long)val);
 		} else {
-				btf_dump_printf(d, "\n%s%s = %u,",
+			fmt_str = is_signed ? "\n%s%s = %lldLL,"
+					    : "\n%s%s = %lluULL,";
+			btf_dump_printf(d, fmt_str,
 					pfx(lvl + 1), name,
-						(__u32)v->val);
+					(unsigned long long)val);
 		}
 	}
+}
+static void btf_dump_emit_enum_def(struct btf_dump *d, __u32 id,
+				   const struct btf_type *t,
+				   int lvl)
+{
+	__u16 vlen = btf_vlen(t);
+
+	btf_dump_printf(d, "enum%s%s",
+			t->name_off ? " " : "",
+			btf_dump_type_name(d, id));
+
+	if (!vlen)
+		return;
+
+	btf_dump_printf(d, " {");
+	if (btf_is_enum(t))
+		btf_dump_emit_enum32_val(d, t, lvl, vlen);
+	else
+		btf_dump_emit_enum64_val(d, t, lvl, vlen);
 	btf_dump_printf(d, "\n%s}", pfx(lvl));
-	}
 }
 
 static void btf_dump_emit_fwd_def(struct btf_dump *d, __u32 id,
@@ -1178,6 +1224,7 @@ static void btf_dump_emit_type_decl(struct btf_dump *d, __u32 id,
 			break;
 		case BTF_KIND_INT:
 		case BTF_KIND_ENUM:
+		case BTF_KIND_ENUM64:
 		case BTF_KIND_FWD:
 		case BTF_KIND_STRUCT:
 		case BTF_KIND_UNION:
@@ -1312,6 +1359,7 @@ static void btf_dump_emit_type_chain(struct btf_dump *d,
 				btf_dump_emit_struct_fwd(d, id, t);
 			break;
 		case BTF_KIND_ENUM:
+		case BTF_KIND_ENUM64:
 			btf_dump_emit_mods(d, decls);
 			/* inline anonymous enum */
 			if (t->name_off == 0 && !d->skip_anon_defs)
@@ -1988,7 +2036,8 @@ static int btf_dump_get_enum_value(struct btf_dump *d,
 				   __u32 id,
 				   __s64 *value)
 {
-	/* handle unaligned enum value */
+	bool is_signed = btf_kflag(t);
+
 	if (!ptr_is_aligned(d->btf, id, data)) {
 		__u64 val;
 		int err;
@@ -2005,13 +2054,13 @@ static int btf_dump_get_enum_value(struct btf_dump *d,
 		*value = *(__s64 *)data;
 		return 0;
 	case 4:
-		*value = *(__s32 *)data;
+		*value = is_signed ? *(__s32 *)data : *(__u32 *)data;
 		return 0;
 	case 2:
-		*value = *(__s16 *)data;
+		*value = is_signed ? *(__s16 *)data : *(__u16 *)data;
 		return 0;
 	case 1:
-		*value = *(__s8 *)data;
+		*value = is_signed ? *(__s8 *)data : *(__u8 *)data;
 		return 0;
 	default:
 		pr_warn("unexpected size %d for enum, id:[%u]\n", t->size, id);
@@ -2024,7 +2073,7 @@ static int btf_dump_enum_data(struct btf_dump *d,
 			      __u32 id,
 			      const void *data)
 {
-	const struct btf_enum *e;
+	bool is_signed;
 	__s64 value;
 	int i, err;
 
@@ -2032,6 +2081,10 @@ static int btf_dump_enum_data(struct btf_dump *d,
 	if (err)
 		return err;
 
+	is_signed = btf_kflag(t);
+	if (btf_is_enum(t)) {
+		const struct btf_enum *e;
+
 		for (i = 0, e = btf_enum(t); i < btf_vlen(t); i++, e++) {
 			if (value != e->val)
 				continue;
@@ -2039,7 +2092,20 @@ static int btf_dump_enum_data(struct btf_dump *d,
 			return 0;
 		}
 
-	btf_dump_type_values(d, "%d", value);
+		btf_dump_type_values(d, is_signed ? "%d" : "%u", value);
+	} else {
+		const struct btf_enum64 *e;
+
+		for (i = 0, e = btf_enum64(t); i < btf_vlen(t); i++, e++) {
+			if (value != btf_enum64_value(e))
+				continue;
+			btf_dump_type_values(d, "%s", btf_name_of(d, e->name_off));
+			return 0;
+		}
+
+		btf_dump_type_values(d, is_signed ? "%lldLL" : "%lluULL",
+				     (unsigned long long)value);
+	}
 	return 0;
 }
 
@@ -2099,6 +2165,7 @@ static int btf_dump_type_data_check_overflow(struct btf_dump *d,
 	case BTF_KIND_FLOAT:
 	case BTF_KIND_PTR:
 	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64:
 		if (data + bits_offset / 8 + size > d->typed_dump->data_end)
 			return -E2BIG;
 		break;
@@ -2203,6 +2270,7 @@ static int btf_dump_type_data_check_zero(struct btf_dump *d,
 		return -ENODATA;
 	}
 	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64:
 		err = btf_dump_get_enum_value(d, t, data, id, &value);
 		if (err)
 			return err;
@@ -2275,6 +2343,7 @@ static int btf_dump_dump_type_data(struct btf_dump *d,
 		err = btf_dump_struct_data(d, t, id, data);
 		break;
 	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64:
 		/* handle bitfield and int enum values */
 		if (bit_sz) {
 			__u64 print_num;