[PATCHv3 6/7] selftests/bpf: Add uprobe session cookie test

Jiri Olsa
2024-09-09T07:47:11Z

Adding uprobe session test that verifies the cookie value
get properly propagated from entry to return program.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
.../bpf/prog_tests/uprobe_multi_test.c | 31 ++++++++++++
.../bpf/progs/uprobe_multi_session_cookie.c | 48 +++++++++++++++++++
2 files changed, 79 insertions(+)
create mode 100644 tools/testing/selftests/bpf/progs/uprobe_multi_session_cookie.c

diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
index cc32288bfe26..8f56066a0195 100644
--- a/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
+++ b/tools/testing/selftests/bpf/prog_tests/uprobe_multi_test.c
@@ -7,6 +7,7 @@
#include "uprobe_multi_bench.skel.h"
#include "uprobe_multi_usdt.skel.h"
#include "uprobe_multi_session.skel.h"
+#include "uprobe_multi_session_cookie.skel.h"
#include "bpf/libbpf_internal.h"
#include "testing_helpers.h"
#include "../sdt.h"
@@ -660,6 +661,34 @@ static void test_session_skel_api(void)
uprobe_multi_session__destroy(skel);
}

+static void test_session_cookie_skel_api(void)
+{
+ struct uprobe_multi_session_cookie *skel = NULL;
+ int err;
+
+ skel = uprobe_multi_session_cookie__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "uprobe_multi_session_cookie__open_and_load"))
+ goto cleanup;
+
+ skel->bss->pid = getpid();
+
+ err = uprobe_multi_session_cookie__attach(skel);
+ if (!ASSERT_OK(err, "uprobe_multi_session_cookie__attach"))
+ goto cleanup;
+
+ /* trigger all probes */
+ uprobe_multi_func_1();
+ uprobe_multi_func_2();
+ uprobe_multi_func_3();
+
+ ASSERT_EQ(skel->bss->test_uprobe_1_result, 1, "test_uprobe_1_result");
+ ASSERT_EQ(skel->bss->test_uprobe_2_result, 2, "test_uprobe_2_result");
+ ASSERT_EQ(skel->bss->test_uprobe_3_result, 3, "test_uprobe_3_result");
+
+cleanup:
+ uprobe_multi_session_cookie__destroy(skel);
+}
+
static void test_bench_attach_uprobe(void)
{
long attach_start_ns = 0, attach_end_ns = 0;
@@ -750,4 +779,6 @@ void test_uprobe_multi_test(void)
test_attach_api_fails();
if (test__start_subtest("session"))
test_session_skel_api();
+ if (test__start_subtest("session_cookie"))
+ test_session_cookie_skel_api();
}
diff --git a/tools/testing/selftests/bpf/progs/uprobe_multi_session_cookie.c b/tools/testing/selftests/bpf/progs/uprobe_multi_session_cookie.c
new file mode 100644
index 000000000000..5befdf944dc6
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/uprobe_multi_session_cookie.c
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <stdbool.h>
+#include "bpf_kfuncs.h"
+
+char _license[] SEC("license") = "GPL";
+
+int pid = 0;
+
+__u64 test_uprobe_1_result = 0;
+__u64 test_uprobe_2_result = 0;
+__u64 test_uprobe_3_result = 0;
+
+static int check_cookie(__u64 val, __u64 *result)
+{
+ __u64 *cookie;
+
+ if (bpf_get_current_pid_tgid() >> 32 != pid)
+ return 1;
+
+ cookie = bpf_session_cookie();
+
+ if (bpf_session_is_return())
+ *result = *cookie == val ? val : 0;
+ else
+ *cookie = val;
+ return 0;
+}
+
+SEC("uprobe.session//proc/self/exe:uprobe_multi_func_1")
+int uprobe_1(struct pt_regs *ctx)
+{
+ return check_cookie(1, &test_uprobe_1_result);
+}
+
+SEC("uprobe.session//proc/self/exe:uprobe_multi_func_2")
+int uprobe_2(struct pt_regs *ctx)
+{
+ return check_cookie(2, &test_uprobe_2_result);
+}
+
+SEC("uprobe.session//proc/self/exe:uprobe_multi_func_3")
+int uprobe_3(struct pt_regs *ctx)
+{
+ return check_cookie(3, &test_uprobe_3_result);
+}
--
2.46.0