On Sat, Mar 23, 2024 at 03:37:21PM +0800, David Gow wrote: > On Tue, 19 Mar 2024 at 18:49, Mickaël Salaün <mic@xxxxxxxxxxx> wrote: > > > > Previously, when a kernel test thread crashed (e.g. NULL pointer > > dereference, general protection fault), the KUnit test hanged for 30 > > seconds and exited with a timeout error. > > > > Fix this issue by waiting on task_struct->vfork_done instead of the > > custom kunit_try_catch.try_completion, and track the execution state by > > initially setting try_result with -EINTR and only setting it to 0 if > > the test passed. > > > > Fix kunit_generic_run_threadfn_adapter() signature by returning 0 > > instead of calling kthread_complete_and_exit(). Because thread's exit > > code is never checked, always set it to 0 to make it clear. > > > > Fix the -EINTR error message, which couldn't be reached until now. > > > > This is tested with a following patch. > > > > Cc: Brendan Higgins <brendanhiggins@xxxxxxxxxx> > > Cc: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx> > > Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> > > Reviewed-by: David Gow <davidgow@xxxxxxxxxx> > > Tested-by: Rae Moar <rmoar@xxxxxxxxxx> > > Signed-off-by: Mickaël Salaün <mic@xxxxxxxxxxx> > > Link: https://lore.kernel.org/r/20240319104857.70783-5-mic@xxxxxxxxxxx > > --- > > > > Changes since v2: > > * s/-EFAULT/-EINTR/ in commit message as spotted by Rae. > > * Add a comment explaining vfork_done as suggested by David. > > * Add David's Reviewed-by. > > * Add Rae's Tested-by. > > > > Changes since v1: > > * Add Kees's Reviewed-by. > > --- > > include/kunit/try-catch.h | 3 --- > > lib/kunit/try-catch.c | 19 ++++++++++++------- > > 2 files changed, 12 insertions(+), 10 deletions(-) > > > > diff --git a/include/kunit/try-catch.h b/include/kunit/try-catch.h > > index c507dd43119d..7c966a1adbd3 100644 > > --- a/include/kunit/try-catch.h > > +++ b/include/kunit/try-catch.h > > @@ -14,13 +14,11 @@ > > > > typedef void (*kunit_try_catch_func_t)(void *); > > > > -struct completion; > > struct kunit; > > > > /** > > * struct kunit_try_catch - provides a generic way to run code which might fail. > > * @test: The test case that is currently being executed. > > - * @try_completion: Completion that the control thread waits on while test runs. > > * @try_result: Contains any errno obtained while running test case. > > * @try: The function, the test case, to attempt to run. > > * @catch: The function called if @try bails out. > > @@ -46,7 +44,6 @@ struct kunit; > > struct kunit_try_catch { > > /* private: internal use only. */ > > struct kunit *test; > > - struct completion *try_completion; > > int try_result; > > kunit_try_catch_func_t try; > > kunit_try_catch_func_t catch; > > diff --git a/lib/kunit/try-catch.c b/lib/kunit/try-catch.c > > index cab8b24b5d5a..7a3910dd78a6 100644 > > --- a/lib/kunit/try-catch.c > > +++ b/lib/kunit/try-catch.c > > @@ -18,7 +18,7 @@ > > void __noreturn kunit_try_catch_throw(struct kunit_try_catch *try_catch) > > { > > try_catch->try_result = -EFAULT; > > - kthread_complete_and_exit(try_catch->try_completion, -EFAULT); > > + kthread_exit(0); > > It turns out kthread_exit() is not exported, so this doesn't work if > KUnit is built as a module. > > I think the options we have are: > - Add EXPORT_SYMBOL(kthread_exit). I'll go this way. This should not be an issue because kthread_complete_and_exit() can already (only) call kthread_exit() if the completion is NULL, but directly calling kthread_exit() is cleaner. > - Keep using out own completion, and kthread_complete_and_exit() > - try_get_module() before spawning the thread, and use > module_put_and_kthread_exit(). > > I think all of these would be okay, but I could've missed something. > > -- David
