[PATCH RFCv3 18/23] selftests/bpf: Add optimized usdt variant for basic usdt test

Jiri Olsa
2025-03-20T11:45:27Z

Adding optimized usdt variant for basic usdt test to check that
usdt arguments are properly passed in optimized code path.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
tools/testing/selftests/bpf/prog_tests/usdt.c | 38 ++++++++++++-------
1 file changed, 25 insertions(+), 13 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/usdt.c b/tools/testing/selftests/bpf/prog_tests/usdt.c
index 495d66414b57..3a5b5230bfa0 100644
--- a/tools/testing/selftests/bpf/prog_tests/usdt.c
+++ b/tools/testing/selftests/bpf/prog_tests/usdt.c
@@ -40,12 +40,19 @@ static void __always_inline trigger_func(int x) {
}
}

-static void subtest_basic_usdt(void)
+static void subtest_basic_usdt(bool optimized)
{
LIBBPF_OPTS(bpf_usdt_opts, opts);
struct test_usdt *skel;
struct test_usdt__bss *bss;
- int err, i;
+ int err, i, called;
+
+#define TRIGGER(x) ({ \
+ trigger_func(x); \
+ if (optimized) \
+ trigger_func(x); \
+ optimized ? 2 : 1; \
+ })

skel = test_usdt__open_and_load();
if (!ASSERT_OK_PTR(skel, "skel_open"))
@@ -66,11 +73,11 @@ static void subtest_basic_usdt(void)
if (!ASSERT_OK_PTR(skel->links.usdt0, "usdt0_link"))
goto cleanup;

- trigger_func(1);
+ called = TRIGGER(1);

- ASSERT_EQ(bss->usdt0_called, 1, "usdt0_called");
- ASSERT_EQ(bss->usdt3_called, 1, "usdt3_called");
- ASSERT_EQ(bss->usdt12_called, 1, "usdt12_called");
+ ASSERT_EQ(bss->usdt0_called, called, "usdt0_called");
+ ASSERT_EQ(bss->usdt3_called, called, "usdt3_called");
+ ASSERT_EQ(bss->usdt12_called, called, "usdt12_called");

ASSERT_EQ(bss->usdt0_cookie, 0xcafedeadbeeffeed, "usdt0_cookie");
ASSERT_EQ(bss->usdt0_arg_cnt, 0, "usdt0_arg_cnt");
@@ -119,11 +126,11 @@ static void subtest_basic_usdt(void)
* bpf_program__attach_usdt() handles this properly and attaches to
* all possible places of USDT invocation.
*/
- trigger_func(2);
+ called += TRIGGER(2);

- ASSERT_EQ(bss->usdt0_called, 2, "usdt0_called");
- ASSERT_EQ(bss->usdt3_called, 2, "usdt3_called");
- ASSERT_EQ(bss->usdt12_called, 2, "usdt12_called");
+ ASSERT_EQ(bss->usdt0_called, called, "usdt0_called");
+ ASSERT_EQ(bss->usdt3_called, called, "usdt3_called");
+ ASSERT_EQ(bss->usdt12_called, called, "usdt12_called");

/* only check values that depend on trigger_func()'s input value */
ASSERT_EQ(bss->usdt3_args[0], 2, "usdt3_arg1");
@@ -142,9 +149,9 @@ static void subtest_basic_usdt(void)
if (!ASSERT_OK_PTR(skel->links.usdt3, "usdt3_reattach"))
goto cleanup;

- trigger_func(3);
+ called += TRIGGER(3);

- ASSERT_EQ(bss->usdt3_called, 3, "usdt3_called");
+ ASSERT_EQ(bss->usdt3_called, called, "usdt3_called");
/* this time usdt3 has custom cookie */
ASSERT_EQ(bss->usdt3_cookie, 0xBADC00C51E, "usdt3_cookie");
ASSERT_EQ(bss->usdt3_arg_cnt, 3, "usdt3_arg_cnt");
@@ -158,6 +165,7 @@ static void subtest_basic_usdt(void)

cleanup:
test_usdt__destroy(skel);
+#undef TRIGGER
}

unsigned short test_usdt_100_semaphore SEC(".probes");
@@ -419,7 +427,11 @@ static void subtest_urandom_usdt(bool auto_attach)
void test_usdt(void)
{
if (test__start_subtest("basic"))
- subtest_basic_usdt();
+ subtest_basic_usdt(false);
+#ifdef __x86_64__
+ if (test__start_subtest("basic_optimized"))
+ subtest_basic_usdt(true);
+#endif
if (test__start_subtest("multispec"))
subtest_multispec_usdt();
if (test__start_subtest("urand_auto_attach"))
--
2.49.0