Commit 80a54566 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov
Browse files

selftests/bpf: validate generic bpf_object and subskel APIs work together 



Add a new subtest validating that bpf_object loaded and initialized
through generic APIs is still interoperable with BPF subskeleton,
including initialization and reading of global variables.

Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20241023043908.3834423-4-andrii@kernel.org


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 137978f4

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

+75 −1
Original line number Diff line number Diff line
@@ -46,7 +46,8 @@ static int subskeleton_lib_subresult(struct bpf_object *obj) 
	return result;

}



void test_subskeleton(void)

/* initialize and load through skeleton, then instantiate subskeleton out of it */

static void subtest_skel_subskeleton(void)

{

	int err, result;

	struct test_subskeleton *skel;
@@ -76,3 +77,76 @@ void test_subskeleton(void) 
cleanup:

	test_subskeleton__destroy(skel);

}



/* initialize and load through generic bpf_object API, then instantiate subskeleton out of it */

static void subtest_obj_subskeleton(void)

{

	int err, result;

	const void *elf_bytes;

	size_t elf_bytes_sz = 0, rodata_sz = 0, bss_sz = 0;

	struct bpf_object *obj;

	const struct bpf_map *map;

	const struct bpf_program *prog;

	struct bpf_link *link = NULL;

	struct test_subskeleton__rodata *rodata;

	struct test_subskeleton__bss *bss;



	elf_bytes = test_subskeleton__elf_bytes(&elf_bytes_sz);

	if (!ASSERT_OK_PTR(elf_bytes, "elf_bytes"))

		return;



	obj = bpf_object__open_mem(elf_bytes, elf_bytes_sz, NULL);

	if (!ASSERT_OK_PTR(obj, "obj_open_mem"))

		return;



	map = bpf_object__find_map_by_name(obj, ".rodata");

	if (!ASSERT_OK_PTR(map, "rodata_map_by_name"))

		goto cleanup;



	rodata = bpf_map__initial_value(map, &rodata_sz);

	if (!ASSERT_OK_PTR(rodata, "rodata_get"))

		goto cleanup;



	rodata->rovar1 = 10;

	rodata->var1 = 1;

	subskeleton_lib_setup(obj);



	err = bpf_object__load(obj);

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

		goto cleanup;



	prog = bpf_object__find_program_by_name(obj, "handler1");

	if (!ASSERT_OK_PTR(prog, "prog_by_name"))

		goto cleanup;



	link = bpf_program__attach(prog);

	if (!ASSERT_OK_PTR(link, "prog_attach"))

		goto cleanup;



	/* trigger tracepoint */

	usleep(1);



	map = bpf_object__find_map_by_name(obj, ".bss");

	if (!ASSERT_OK_PTR(map, "bss_map_by_name"))

		goto cleanup;



	bss = bpf_map__initial_value(map, &bss_sz);

	if (!ASSERT_OK_PTR(rodata, "rodata_get"))

		goto cleanup;



	result = subskeleton_lib_subresult(obj) * 10;

	ASSERT_EQ(bss->out1, result, "out1");



cleanup:

	bpf_link__destroy(link);

	bpf_object__close(obj);

}





void test_subskeleton(void)

{

	if (test__start_subtest("skel_subskel"))

		subtest_skel_subskeleton();

	if (test__start_subtest("obj_subskel"))

		subtest_obj_subskeleton();

}