[PATCHv3 perf/core 6/6] selftests/bpf: Add kprobe multi write ctx attach test

Jiri Olsa posted 6 patches 12 hours ago
[PATCHv3 perf/core 6/6] selftests/bpf: Add kprobe multi write ctx attach test
Posted by Jiri Olsa 12 hours ago
Adding test to check we can't attach kprobe multi program
that writes to the context.

It's x86_64 specific test.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 .../bpf/prog_tests/kprobe_multi_test.c        | 27 +++++++++++++++++++
 .../selftests/bpf/progs/kprobe_write_ctx.c    |  7 +++++
 2 files changed, 34 insertions(+)

diff --git a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c
index e19ef509ebf8..bc52389217e2 100644
--- a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c
+++ b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c
@@ -7,6 +7,7 @@
 #include "kprobe_multi_session.skel.h"
 #include "kprobe_multi_session_cookie.skel.h"
 #include "kprobe_multi_verifier.skel.h"
+#include "kprobe_write_ctx.skel.h"
 #include "bpf/libbpf_internal.h"
 #include "bpf/hashmap.h"
 
@@ -753,6 +754,30 @@ static void test_attach_override(void)
 	kprobe_multi_override__destroy(skel);
 }
 
+#ifdef __x86_64__
+static void test_attach_write_ctx(void)
+{
+	struct kprobe_write_ctx *skel = NULL;
+	struct bpf_link *link = NULL;
+
+	skel = kprobe_write_ctx__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "kprobe_write_ctx__open_and_load"))
+		return;
+
+	link = bpf_program__attach_kprobe_opts(skel->progs.kprobe_multi_write_ctx,
+						     "bpf_fentry_test1", NULL);
+	if (!ASSERT_ERR_PTR(link, "bpf_program__attach_kprobe_opts"))
+		bpf_link__destroy(link);
+
+	kprobe_write_ctx__destroy(skel);
+}
+#else
+static void test_attach_write_ctx(void)
+{
+	test__skip();
+}
+#endif
+
 void serial_test_kprobe_multi_bench_attach(void)
 {
 	if (test__start_subtest("kernel"))
@@ -792,5 +817,7 @@ void test_kprobe_multi_test(void)
 		test_session_cookie_skel_api();
 	if (test__start_subtest("unique_match"))
 		test_unique_match();
+	if (test__start_subtest("attach_write_ctx"))
+		test_attach_write_ctx();
 	RUN_TESTS(kprobe_multi_verifier);
 }
diff --git a/tools/testing/selftests/bpf/progs/kprobe_write_ctx.c b/tools/testing/selftests/bpf/progs/kprobe_write_ctx.c
index 4621a5bef4e2..f77aef0474d3 100644
--- a/tools/testing/selftests/bpf/progs/kprobe_write_ctx.c
+++ b/tools/testing/selftests/bpf/progs/kprobe_write_ctx.c
@@ -12,4 +12,11 @@ int kprobe_write_ctx(struct pt_regs *ctx)
 	ctx->ax = 0;
 	return 0;
 }
+
+SEC("kprobe.multi")
+int kprobe_multi_write_ctx(struct pt_regs *ctx)
+{
+	ctx->ax = 0;
+	return 0;
+}
 #endif
-- 
2.51.0