Commit 30bbfe32 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov
Browse files

selftests/bpf: add missing __weak kfunc log fixup test 



Add test validating that libbpf correctly poisons and reports __weak
unresolved kfuncs in post-processed verifier log.

Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230418002148.3255690-5-andrii@kernel.org


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 05b6f766

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

+31 −0
Original line number Diff line number Diff line
@@ -135,6 +135,35 @@ static void missing_map(void) 
	test_log_fixup__destroy(skel);

}



static void missing_kfunc(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_program__set_autoload(skel->progs.use_missing_kfunc, true);

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



	err = test_log_fixup__load(skel);

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

		goto cleanup;



	ASSERT_HAS_SUBSTR(log_buf,

			  "0: <invalid kfunc call>\n"

			  "kfunc 'bpf_nonexistent_kfunc' is referenced but wasn't resolved\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"))
@@ -147,4 +176,6 @@ void test_log_fixup(void) 
		bad_core_relo_subprog();

	if (test__start_subtest("missing_map"))

		missing_map();

	if (test__start_subtest("missing_kfunc"))

		missing_kfunc();

}

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

+10 −0
Original line number Diff line number Diff line
@@ -61,4 +61,14 @@ int use_missing_map(const void *ctx) 
	return value != NULL;

}



extern int bpf_nonexistent_kfunc(void) __ksym __weak;



SEC("?raw_tp/sys_enter")

int use_missing_kfunc(const void *ctx)

{

	bpf_nonexistent_kfunc();



	return 0;

}



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