selftests/harness: Share _metadata between forked processes

Unconditionally share _metadata between all forked processes, which
enables to actually catch errors which were previously ignored.

This is required for a following commit replacing vfork() with clone3()
and CLONE_VFORK (i.e. not sharing the full memory) .  It should also be
useful to share _metadata to extend expectations to test process's
forks.  For instance, this change identified a wrong expectation in
pidfd_setns_test.

Because this _metadata is used by the new XFAIL_ADD(), use a global
pointer initialized in TEST_F().  This is OK because only XFAIL_ADD()
use it, and XFAIL_ADD() already depends on TEST_F().

Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Will Drewry <wad@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20240511171445.904356-9-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>

diff --git a/tools/testing/selftests/kselftest_harness.h b/tools/testing/selftests/kselftest_harness.h
index 201040207c852d1316d5d1fb508aa4354bc3e0ae..28415798fa6011d55a6b596bbdeaac5f0c36b97c 100644 (file)
--- a/tools/testing/selftests/kselftest_harness.h
+++ b/tools/testing/selftests/kselftest_harness.h
@@ -430,19 +430,19 @@ static inline pid_t clone3_vfork(void)
                        kill(getpid(), WTERMSIG(status)); \
                __test_check_assert(_metadata); \
        } \
-       static struct __test_metadata \
-                     _##fixture_name##_##test_name##_object = { \
-               .name = #test_name, \
-               .fn = &wrapper_##fixture_name##_##test_name, \
-               .fixture = &_##fixture_name##_fixture_object, \
-               .termsig = signal, \
-               .timeout = tmout, \
-               .teardown_parent = false, \
-        }; \
+       static struct __test_metadata *_##fixture_name##_##test_name##_object; \
        static void __attribute__((constructor)) \
                        _register_##fixture_name##_##test_name(void) \
        { \
-               __register_test(&_##fixture_name##_##test_name##_object); \
+               struct __test_metadata *object = mmap(NULL, sizeof(*object), \
+                       PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0); \
+               object->name = #test_name; \
+               object->fn = &wrapper_##fixture_name##_##test_name; \
+               object->fixture = &_##fixture_name##_fixture_object; \
+               object->termsig = signal; \
+               object->timeout = tmout; \
+               _##fixture_name##_##test_name##_object = object; \
+               __register_test(object); \
        } \
        static void fixture_name##_##test_name( \
                struct __test_metadata __attribute__((unused)) *_metadata, \
@@ -850,11 +850,12 @@ struct __test_xfail {
        { \
                .fixture = &_##fixture_name##_fixture_object, \
                .variant = &_##fixture_name##_##variant_name##_object, \
-               .test = &_##fixture_name##_##test_name##_object, \
        }; \
        static void __attribute__((constructor)) \
                _register_##fixture_name##_##variant_name##_##test_name##_xfail(void) \
        { \
+               _##fixture_name##_##variant_name##_##test_name##_xfail.test = \
+                       _##fixture_name##_##test_name##_object; \
                __register_xfail(&_##fixture_name##_##variant_name##_##test_name##_xfail); \
        }
 
@@ -1181,6 +1182,9 @@ void __run_test(struct __fixture_metadata *f,
        /* reset test struct */
        t->exit_code = KSFT_PASS;
        t->trigger = 0;
+       t->aborted = false;
+       t->setup_completed = false;
+       memset(t->env, 0, sizeof(t->env));
        memset(t->results->reason, 0, sizeof(t->results->reason));
 
        if (asprintf(&test_name, "%s%s%s.%s", f->name,