Commit a1c05c3b authored by Jiri Olsa's avatar Jiri Olsa Committed by Alexei Starovoitov
Browse files

selftests/bpf: Test that module can't be unloaded with attached trampoline 



Adding test to verify that once we attach module's trampoline,
the module can't be unloaded.

Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210414195147.1624932-7-jolsa@kernel.org
parent cede72ad

tools/testing/selftests/bpf/prog_tests/module_attach.c

+23 −0
Original line number Diff line number Diff line
@@ -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);

}