diff options
| author | David Gow <davidgow@google.com> | 2024-04-12 10:59:01 +0800 |
|---|---|---|
| committer | Shuah Khan <skhan@linuxfoundation.org> | 2024-05-06 14:22:02 -0600 |
| commit | 1eb69ded805103ce3ddc8b1a207abd8c24ca9e63 (patch) | |
| tree | 9e8afefdc5a53cb728cb11881ce3f8786d024f64 | |
| parent | 170c31737cf31770916c6cbadab04c5134f0d961 (diff) | |
kunit: Fix race condition in try-catch completion
KUnit's try-catch infrastructure now uses vfork_done, which is always
set to a valid completion when a kthread is created, but which is set to
NULL once the thread terminates. This creates a race condition, where
the kthread exits before we can wait on it.
Keep a copy of vfork_done, which is taken before we wake_up_process()
and so valid, and wait on that instead.
Fixes: 93533996100c ("kunit: Handle test faults")
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Closes: https://lore.kernel.org/lkml/20240410102710.35911-1-naresh.kamboju@linaro.org/
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Acked-by: Mickaël Salaün <mic@digikod.net>
Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Rae Moar <rmoar@google.com>
Tested-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
| -rw-r--r-- | lib/kunit/try-catch.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/lib/kunit/try-catch.c b/lib/kunit/try-catch.c index fa687278ccc9..6bbe0025b079 100644 --- a/lib/kunit/try-catch.c +++ b/lib/kunit/try-catch.c @@ -63,6 +63,7 @@ void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context) { struct kunit *test = try_catch->test; struct task_struct *task_struct; + struct completion *task_done; int exit_code, time_remaining; try_catch->context = context; @@ -75,13 +76,16 @@ void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context) return; } get_task_struct(task_struct); - wake_up_process(task_struct); /* * As for a vfork(2), task_struct->vfork_done (pointing to the * underlying kthread->exited) can be used to wait for the end of a - * kernel thread. + * kernel thread. It is set to NULL when the thread exits, so we + * keep a copy here. */ - time_remaining = wait_for_completion_timeout(task_struct->vfork_done, + task_done = task_struct->vfork_done; + wake_up_process(task_struct); + + time_remaining = wait_for_completion_timeout(task_done, kunit_test_timeout()); if (time_remaining == 0) { try_catch->try_result = -ETIMEDOUT; |