[PATCHv5 bpf-next 6/7] selftests/bpf: Test that module can't be unloaded with attached trampoline
From: Jiri Olsa <jolsa@kernel.org>
Date: 2021-04-14 19:52:35
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [selftests] (test runners & infrastructure), kernel selftest framework, the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Shuah Khan, Linus Torvalds
Adding test to verify that once we attach module's trampoline, the module can't be unloaded. Acked-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> --- .../selftests/bpf/prog_tests/module_attach.c | 23 +++++++++++++++++++ 1 file changed, 23 insertions(+)
diff --git a/tools/testing/selftests/bpf/prog_tests/module_attach.c b/tools/testing/selftests/bpf/prog_tests/module_attach.c
index 5bc53d53d86e..d85a69b7ce44 100644
--- a/tools/testing/selftests/bpf/prog_tests/module_attach.c
+++ b/tools/testing/selftests/bpf/prog_tests/module_attach.c@@ -45,12 +45,18 @@ static int trigger_module_test_write(int write_sz) return 0; } +static int delete_module(const char *name, int flags) +{ + return syscall(__NR_delete_module, name, flags); +} + void test_module_attach(void) { const int READ_SZ = 456; const int WRITE_SZ = 457; struct test_module_attach* skel; struct test_module_attach__bss *bss; + struct bpf_link *link; int err; skel = test_module_attach__open();
@@ -84,6 +90,23 @@ void test_module_attach(void) ASSERT_EQ(bss->fexit_ret, -EIO, "fexit_tet"); ASSERT_EQ(bss->fmod_ret_read_sz, READ_SZ, "fmod_ret"); + test_module_attach__detach(skel); + + /* attach fentry/fexit and make sure it get's module reference */ + link = bpf_program__attach(skel->progs.handle_fentry); + if (!ASSERT_OK_PTR(link, "attach_fentry")) + goto cleanup; + + ASSERT_ERR(delete_module("bpf_testmod", 0), "delete_module"); + bpf_link__destroy(link); + + link = bpf_program__attach(skel->progs.handle_fexit); + if (!ASSERT_OK_PTR(link, "attach_fexit")) + goto cleanup; + + ASSERT_ERR(delete_module("bpf_testmod", 0), "delete_module"); + bpf_link__destroy(link); + cleanup: test_module_attach__destroy(skel); }
--
2.30.2