[PATCH bpf-next v2 6/8] selftests/bpf: Cover record attributes in bpftool BTF dumps

[Ihor Solodrai <ihor.solodrai@linux.dev>]

Types whose field accesses need static offsets carry __bpf_static_offset,
while their nested anonymous records must stay unannotated. Other
records retain __bpf_relocatable, including context types such as
bpf_nf_ctx whose accesses do not need static offsets.

Extend the existing C dump test fixture with selected context and
socket types and recursively nested anonymous unions.

Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
---
 .../bpf/bpftool_btf_dump_sorted.expected      | 24 ++++++++++
 .../bpf/bpftool_btf_dump_unsorted.expected    | 24 ++++++++++
 .../bpf/prog_tests/bpftool_btf_dump.c         | 47 +++++++++++++++++++
 3 files changed, 95 insertions(+)

diff --git a/tools/testing/selftests/bpf/bpftool_btf_dump_sorted.expected b/tools/testing/selftests/bpf/bpftool_btf_dump_sorted.expected
index 9166a99a6077..38cec98ddedd 100644
--- a/tools/testing/selftests/bpf/bpftool_btf_dump_sorted.expected
+++ b/tools/testing/selftests/bpf/bpftool_btf_dump_sorted.expected
@@ -37,6 +37,30 @@ enum {
 	E0 = 1,
 };
 
+struct __sk_buff {
+	int len;
+	union {
+		int sk;
+	};
+} __attribute__((__bpf_static_offset));
+
+struct bpf_nf_ctx {
+	int f;
+} __attribute__((__bpf_relocatable));
+
+struct bpf_sk_lookup {
+	union {
+		union {
+			int cookie;
+		};
+		int family;
+	};
+} __attribute__((__bpf_static_offset));
+
+struct bpf_tcp_sock {
+	int snd_cwnd;
+} __attribute__((__bpf_static_offset));
+
 struct holey {
 	int c;
 	long: 32;
diff --git a/tools/testing/selftests/bpf/bpftool_btf_dump_unsorted.expected b/tools/testing/selftests/bpf/bpftool_btf_dump_unsorted.expected
index ef01a8a4e6ad..81f58181da14 100644
--- a/tools/testing/selftests/bpf/bpftool_btf_dump_unsorted.expected
+++ b/tools/testing/selftests/bpf/bpftool_btf_dump_unsorted.expected
@@ -48,6 +48,30 @@ struct s {
 	int f;
 } __attribute__((__bpf_relocatable));
 
+struct __sk_buff {
+	int len;
+	union {
+		int sk;
+	};
+} __attribute__((__bpf_static_offset));
+
+struct bpf_sk_lookup {
+	union {
+		union {
+			int cookie;
+		};
+		int family;
+	};
+} __attribute__((__bpf_static_offset));
+
+struct bpf_tcp_sock {
+	int snd_cwnd;
+} __attribute__((__bpf_static_offset));
+
+struct bpf_nf_ctx {
+	int f;
+} __attribute__((__bpf_relocatable));
+
 
 /* BPF kfuncs */
 #ifndef BPF_NO_KFUNC_PROTOTYPES
diff --git a/tools/testing/selftests/bpf/prog_tests/bpftool_btf_dump.c b/tools/testing/selftests/bpf/prog_tests/bpftool_btf_dump.c
index 9104c059a315..0277f054410c 100644
--- a/tools/testing/selftests/bpf/prog_tests/bpftool_btf_dump.c
+++ b/tools/testing/selftests/bpf/prog_tests/bpftool_btf_dump.c
@@ -20,6 +20,18 @@
  *	};
  *	enum { E0 = 1 };
  *	struct s { int f; };
+ *	struct __sk_buff {
+ *		int len;
+ *		union { int sk; };
+ *	};
+ *	struct bpf_sk_lookup {
+ *		union {
+ *			union { int cookie; };
+ *			int family;
+ *		};
+ *	};
+ *	struct bpf_tcp_sock { int snd_cwnd; };
+ *	struct bpf_nf_ctx { int f; };
  */
 static struct btf *mk_btf(void)
 {
@@ -42,6 +54,25 @@ static struct btf *mk_btf(void)
 	btf__add_struct(btf, "s", 4);
 	btf__add_field(btf, "f", 1, 0, 0);
 
+	btf__add_union(btf, NULL, 4);
+	btf__add_field(btf, "sk", 1, 0, 0);
+	btf__add_struct(btf, "__sk_buff", 8);
+	btf__add_field(btf, "len", 1, 0, 0);
+	btf__add_field(btf, NULL, 6, 32, 0);
+
+	btf__add_union(btf, NULL, 4);
+	btf__add_field(btf, "cookie", 1, 0, 0);
+	btf__add_union(btf, NULL, 4);
+	btf__add_field(btf, NULL, 8, 0, 0);
+	btf__add_field(btf, "family", 1, 0, 0);
+	btf__add_struct(btf, "bpf_sk_lookup", 4);
+	btf__add_field(btf, NULL, 9, 0, 0);
+
+	btf__add_struct(btf, "bpf_tcp_sock", 4);
+	btf__add_field(btf, "snd_cwnd", 1, 0, 0);
+	btf__add_struct(btf, "bpf_nf_ctx", 4);
+	btf__add_field(btf, "f", 1, 0, 0);
+
 	VALIDATE_RAW_BTF(
 		btf,
 		"[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
@@ -52,6 +83,22 @@ static struct btf *mk_btf(void)
 		"[4] ENUM '(anon)' encoding=UNSIGNED size=4 vlen=1\n"
 		"\t'E0' val=1",
 		"[5] STRUCT 's' size=4 vlen=1\n"
+		"\t'f' type_id=1 bits_offset=0",
+		"[6] UNION '(anon)' size=4 vlen=1\n"
+		"\t'sk' type_id=1 bits_offset=0",
+		"[7] STRUCT '__sk_buff' size=8 vlen=2\n"
+		"\t'len' type_id=1 bits_offset=0\n"
+		"\t'(anon)' type_id=6 bits_offset=32",
+		"[8] UNION '(anon)' size=4 vlen=1\n"
+		"\t'cookie' type_id=1 bits_offset=0",
+		"[9] UNION '(anon)' size=4 vlen=2\n"
+		"\t'(anon)' type_id=8 bits_offset=0\n"
+		"\t'family' type_id=1 bits_offset=0",
+		"[10] STRUCT 'bpf_sk_lookup' size=4 vlen=1\n"
+		"\t'(anon)' type_id=9 bits_offset=0",
+		"[11] STRUCT 'bpf_tcp_sock' size=4 vlen=1\n"
+		"\t'snd_cwnd' type_id=1 bits_offset=0",
+		"[12] STRUCT 'bpf_nf_ctx' size=4 vlen=1\n"
 		"\t'f' type_id=1 bits_offset=0");
 
 	return btf;
-- 
2.56.0