[PATCH v5 03/10] selftests/harness: Fix fixture teardown

Mickaël Salaün
2024-05-03T10:58:41Z

Make sure fixture teardowns are run when test cases failed, including
when _metadata->teardown_parent is set to true.

Make sure only one fixture teardown is run per test case, handling the
case where the test child forks.

Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Shengyu Li <shengyu.li.evgeny@gmail.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Fixes: 72d7cb5c190b ("selftests/harness: Prevent infinite loop due to Assert in FIXTURE_TEARDOWN")
Fixes: 0710a1a73fb4 ("selftests/harness: Merge TEST_F_FORK() into TEST_F()")
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Link: https://lore.kernel.org/r/20240503105820.300927-4-mic@digikod.net
---
tools/testing/selftests/kselftest_harness.h | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/kselftest_harness.h b/tools/testing/selftests/kselftest_harness.h
index d98702b6955d..55699a762c45 100644
--- a/tools/testing/selftests/kselftest_harness.h
+++ b/tools/testing/selftests/kselftest_harness.h
@@ -382,7 +382,10 @@
FIXTURE_DATA(fixture_name) self; \
pid_t child = 1; \
int status = 0; \
- bool jmp = false; \
+ /* Makes sure there is only one teardown, even when child forks again. */ \
+ bool *teardown = mmap(NULL, sizeof(*teardown), \
+ PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0); \
+ *teardown = false; \
memset(&self, 0, sizeof(FIXTURE_DATA(fixture_name))); \
if (setjmp(_metadata->env) == 0) { \
/* Use the same _metadata. */ \
@@ -399,15 +402,16 @@
_metadata->exit_code = KSFT_FAIL; \
} \
} \
- else \
- jmp = true; \
if (child == 0) { \
- if (_metadata->setup_completed && !_metadata->teardown_parent && !jmp) \
+ if (_metadata->setup_completed && !_metadata->teardown_parent && \
+ __sync_bool_compare_and_swap(teardown, false, true)) \
fixture_name##_teardown(_metadata, &self, variant->data); \
_exit(0); \
} \
- if (_metadata->setup_completed && _metadata->teardown_parent) \
+ if (_metadata->setup_completed && _metadata->teardown_parent && \
+ __sync_bool_compare_and_swap(teardown, false, true)) \
fixture_name##_teardown(_metadata, &self, variant->data); \
+ munmap(teardown, sizeof(*teardown)); \
if (!WIFEXITED(status) && WIFSIGNALED(status)) \
/* Forward signal to __wait_for_test(). */ \
kill(getpid(), WTERMSIG(status)); \
--
2.45.0