Commit 1bba3b3d authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Martin KaFai Lau
Browse files

selftests/bpf: validate nulled-out struct_ops program is handled properly 



Add a selftests validating that it's possible to have some struct_ops
callback set declaratively, then disable it (by setting to NULL)
programmatically. Libbpf should detect that such program should
not be loaded. Otherwise, it will unnecessarily fail the loading
when the host kernel does not have the type information.

Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240428030954.3918764-2-andrii@kernel.org


Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
parent f973fccd

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

+16 −2
Original line number Diff line number Diff line
@@ -66,6 +66,7 @@ static void test_struct_ops_load(void) 
	 * auto-loading, or it will fail to load.

	 */

	bpf_program__set_autoload(skel->progs.test_2, false);

	bpf_map__set_autocreate(skel->maps.testmod_zeroed, false);



	err = struct_ops_module__load(skel);

	if (!ASSERT_OK(err, "struct_ops_module_load"))
@@ -103,6 +104,10 @@ static void test_struct_ops_not_zeroed(void) 
	if (!ASSERT_OK_PTR(skel, "struct_ops_module_open"))

		return;



	skel->struct_ops.testmod_zeroed->zeroed = 0;

	/* zeroed_op prog should be not loaded automatically now */

	skel->struct_ops.testmod_zeroed->zeroed_op = NULL;



	err = struct_ops_module__load(skel);

	ASSERT_OK(err, "struct_ops_module_load");
@@ -118,6 +123,7 @@ static void test_struct_ops_not_zeroed(void) 
	 * value of "zeroed" is non-zero.

	 */

	skel->struct_ops.testmod_zeroed->zeroed = 0xdeadbeef;

	skel->struct_ops.testmod_zeroed->zeroed_op = NULL;

	err = struct_ops_module__load(skel);

	ASSERT_ERR(err, "struct_ops_module_load_not_zeroed");
@@ -148,15 +154,23 @@ static void test_struct_ops_incompatible(void) 
{

	struct struct_ops_module *skel;

	struct bpf_link *link;

	int err;



	skel = struct_ops_module__open_and_load();

	if (!ASSERT_OK_PTR(skel, "open_and_load"))

	skel = struct_ops_module__open();

	if (!ASSERT_OK_PTR(skel, "struct_ops_module_open"))

		return;



	bpf_map__set_autocreate(skel->maps.testmod_zeroed, false);



	err = struct_ops_module__load(skel);

	if (!ASSERT_OK(err, "skel_load"))

		goto cleanup;



	link = bpf_map__attach_struct_ops(skel->maps.testmod_incompatible);

	if (ASSERT_OK_PTR(link, "attach_struct_ops"))

		bpf_link__destroy(link);



cleanup:

	struct_ops_module__destroy(skel);

}

tools/testing/selftests/bpf/progs/struct_ops_module.c

+7 −0
Original line number Diff line number Diff line
@@ -63,10 +63,17 @@ struct bpf_testmod_ops___zeroed { 
	int zeroed;

};



SEC("?struct_ops/test_3")

int BPF_PROG(zeroed_op)

{

	return 1;

}



SEC(".struct_ops.link")

struct bpf_testmod_ops___zeroed testmod_zeroed = {

	.test_1 = (void *)test_1,

	.test_2 = (void *)test_2_v2,

	.zeroed_op = (void *)zeroed_op,

};



struct bpf_testmod_ops___incompatible {