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From: =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= <mic@digikod.net>
To: Christian Brauner <brauner@kernel.org>,
	Jakub Kicinski <kuba@kernel.org>,
	Kees Cook <keescook@chromium.org>,
	Mark Brown <broonie@kernel.org>,
	Shengyu Li <shengyu.li.evgeny@gmail.com>,
	Shuah Khan <shuah@kernel.org>
Cc: =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= <mic@digikod.net>,
	"David S . Miller" <davem@davemloft.net>,
	=?UTF-8?q?G=C3=BCnther=20Noack?= <gnoack@google.com>,
	Will Drewry <wad@chromium.org>,
	kernel test robot <oliver.sang@intel.com>,
	linux-kernel@vger.kernel.org,
	linux-kselftest@vger.kernel.org,
	Shuah Khan <skhan@linuxfoundation.org>
Subject: [PATCH v3 3/9] selftests/harness: Fix fixture teardown
Date: Mon, 29 Apr 2024 21:19:05 +0200
Message-ID: <20240429191911.2552580-4-mic@digikod.net>
In-Reply-To: <20240429191911.2552580-1-mic@digikod.net>
References: <20240429191911.2552580-1-mic@digikod.net>
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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/20240429191911.2552580-4-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)); \
-- 
2.44.0