Commit 68964e15 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov
Browse files

selftests/bpf: Test bpf_map__set_autocreate() and related log fixup logic 



Add a subtest that excercises bpf_map__set_autocreate() API and
validates that libbpf properly fixes up BPF verifier log with correct
map information.

Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220428041523.4089853-5-andrii@kernel.org
parent ec41817b

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

+36 −1
Original line number Diff line number Diff line
@@ -85,7 +85,6 @@ static void bad_core_relo_subprog(void) 
	if (!ASSERT_ERR(err, "load_fail"))

		goto cleanup;



	/* there should be no prog loading log because we specified per-prog log buf */

	ASSERT_HAS_SUBSTR(log_buf,

			  ": <invalid CO-RE relocation>\n"

			  "failed to resolve CO-RE relocation <byte_off> ",
@@ -101,6 +100,40 @@ static void bad_core_relo_subprog(void) 
	test_log_fixup__destroy(skel);

}



static void missing_map(void)

{

	char log_buf[8 * 1024];

	struct test_log_fixup* skel;

	int err;



	skel = test_log_fixup__open();

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

		return;



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



	bpf_program__set_autoload(skel->progs.use_missing_map, true);

	bpf_program__set_log_buf(skel->progs.use_missing_map, log_buf, sizeof(log_buf));



	err = test_log_fixup__load(skel);

	if (!ASSERT_ERR(err, "load_fail"))

		goto cleanup;



	ASSERT_TRUE(bpf_map__autocreate(skel->maps.existing_map), "existing_map_autocreate");

	ASSERT_FALSE(bpf_map__autocreate(skel->maps.missing_map), "missing_map_autocreate");



	ASSERT_HAS_SUBSTR(log_buf,

			  "8: <invalid BPF map reference>\n"

			  "BPF map 'missing_map' is referenced but wasn't created\n",

			  "log_buf");



	if (env.verbosity > VERBOSE_NONE)

		printf("LOG:   \n=================\n%s=================\n", log_buf);



cleanup:

	test_log_fixup__destroy(skel);

}



void test_log_fixup(void)

{

	if (test__start_subtest("bad_core_relo_trunc_none"))
@@ -111,4 +144,6 @@ void test_log_fixup(void) 
		bad_core_relo(250, TRUNC_FULL  /* truncate also libbpf's message patch */);

	if (test__start_subtest("bad_core_relo_subprog"))

		bad_core_relo_subprog();

	if (test__start_subtest("missing_map"))

		missing_map();

}

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

+26 −0
Original line number Diff line number Diff line
@@ -35,4 +35,30 @@ int bad_relo_subprog(const void *ctx) 
	return bad_subprog() + bpf_core_field_size(t->pid);

}



struct {

	__uint(type, BPF_MAP_TYPE_ARRAY);

	__uint(max_entries, 1);

	__type(key, int);

	__type(value, int);

} existing_map SEC(".maps");



struct {

	__uint(type, BPF_MAP_TYPE_ARRAY);

	__uint(max_entries, 1);

	__type(key, int);

	__type(value, int);

} missing_map SEC(".maps");



SEC("?raw_tp/sys_enter")

int use_missing_map(const void *ctx)

{

	int zero = 0, *value;



	value = bpf_map_lookup_elem(&existing_map, &zero);



	value = bpf_map_lookup_elem(&missing_map, &zero);



	return value != NULL;

}



char _license[] SEC("license") = "GPL";