From: Yonghong Song <yhs@fb.com>
Date: Thu, 11 Nov 2021 17:26:46 -0800
Subject: selftests/bpf: Add a C test for btf_type_tag
Patch-mainline: v5.17-rc1
Git-commit: 5698a42a73a1d9cb7efd31ca1bf35daa87f5e1a9
References: jsc#PED-1377
The following is the main btf_type_tag usage in the
C test:
#define __tag1 __attribute__((btf_type_tag("tag1")))
#define __tag2 __attribute__((btf_type_tag("tag2")))
struct btf_type_tag_test {
int __tag1 * __tag1 __tag2 *p;
} g;
The bpftool raw dump with related types:
[4] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED
[11] STRUCT 'btf_type_tag_test' size=8 vlen=1
'p' type_id=14 bits_offset=0
[12] TYPE_TAG 'tag1' type_id=16
[13] TYPE_TAG 'tag2' type_id=12
[14] PTR '(anon)' type_id=13
[15] TYPE_TAG 'tag1' type_id=4
[16] PTR '(anon)' type_id=15
[17] VAR 'g' type_id=11, linkage=global
With format C dump, we have
struct btf_type_tag_test {
int __attribute__((btf_type_tag("tag1"))) * __attribute__((btf_type_tag("tag1"))) __attribute__((btf_type_tag("tag2"))) *p;
};
The result C code is identical to the original definition except macro's are gone.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211112012646.1508231-1-yhs@fb.com
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
tools/testing/selftests/bpf/prog_tests/btf_tag.c | 24 ++++++++++++++++++++++
tools/testing/selftests/bpf/progs/btf_type_tag.c | 25 +++++++++++++++++++++++
2 files changed, 49 insertions(+)
create mode 100644 tools/testing/selftests/bpf/progs/btf_type_tag.c
--- a/tools/testing/selftests/bpf/prog_tests/btf_tag.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf_tag.c
@@ -3,6 +3,12 @@
#include <test_progs.h>
#include "btf_decl_tag.skel.h"
+/* struct btf_type_tag_test is referenced in btf_type_tag.skel.h */
+struct btf_type_tag_test {
+ int **p;
+};
+#include "btf_type_tag.skel.h"
+
static void test_btf_decl_tag(void)
{
struct btf_decl_tag *skel;
@@ -19,8 +25,26 @@ static void test_btf_decl_tag(void)
btf_decl_tag__destroy(skel);
}
+static void test_btf_type_tag(void)
+{
+ struct btf_type_tag *skel;
+
+ skel = btf_type_tag__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "btf_type_tag"))
+ return;
+
+ if (skel->rodata->skip_tests) {
+ printf("%s:SKIP: btf_type_tag attribute not supported", __func__);
+ test__skip();
+ }
+
+ btf_type_tag__destroy(skel);
+}
+
void test_btf_tag(void)
{
if (test__start_subtest("btf_decl_tag"))
test_btf_decl_tag();
+ if (test__start_subtest("btf_type_tag"))
+ test_btf_type_tag();
}
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf_type_tag.c
@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2021 Facebook */
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+#if __has_attribute(btf_type_tag)
+#define __tag1 __attribute__((btf_type_tag("tag1")))
+#define __tag2 __attribute__((btf_type_tag("tag2")))
+volatile const bool skip_tests = false;
+#else
+#define __tag1
+#define __tag2
+volatile const bool skip_tests = true;
+#endif
+
+struct btf_type_tag_test {
+ int __tag1 * __tag1 __tag2 *p;
+} g;
+
+SEC("fentry/bpf_fentry_test1")
+int BPF_PROG(sub, int x)
+{
+ return 0;
+}