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authorMickaël Salaün <mic@digikod.net>2024-04-08 09:46:22 +0200
committerShuah Khan <skhan@linuxfoundation.org>2024-05-06 14:22:02 -0600
commit3a35c13007dea132a65f07de05c26b87837fadc2 (patch)
treeb4b11cedb2ba19351da4ccccd0c71d08bfe30460 /lib
parent53026ff63bb07c04a0e962a74723eb10ff6f9dc7 (diff)
kunit: Handle test faults
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. To make this explicit, export kthread_exit() for KUnit tests built as module. Fix the -EINTR error message, which couldn't be reached until now. This is tested with a following patch. Cc: Brendan Higgins <brendanhiggins@google.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: David Gow <davidgow@google.com> Tested-by: Rae Moar <rmoar@google.com> Signed-off-by: Mickaël Salaün <mic@digikod.net> Link: https://lore.kernel.org/r/20240408074625.65017-5-mic@digikod.net Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/kunit/try-catch.c19
1 files changed, 12 insertions, 7 deletions
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);
}
EXPORT_SYMBOL_GPL(kunit_try_catch_throw);
@@ -26,9 +26,12 @@ static int kunit_generic_run_threadfn_adapter(void *data)
{
struct kunit_try_catch *try_catch = data;
+ try_catch->try_result = -EINTR;
try_catch->try(try_catch->context);
+ if (try_catch->try_result == -EINTR)
+ try_catch->try_result = 0;
- kthread_complete_and_exit(try_catch->try_completion, 0);
+ return 0;
}
static unsigned long kunit_test_timeout(void)
@@ -58,13 +61,11 @@ static unsigned long kunit_test_timeout(void)
void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context)
{
- DECLARE_COMPLETION_ONSTACK(try_completion);
struct kunit *test = try_catch->test;
struct task_struct *task_struct;
int exit_code, time_remaining;
try_catch->context = context;
- try_catch->try_completion = &try_completion;
try_catch->try_result = 0;
task_struct = kthread_create(kunit_generic_run_threadfn_adapter,
try_catch, "kunit_try_catch_thread");
@@ -75,8 +76,12 @@ void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context)
}
get_task_struct(task_struct);
wake_up_process(task_struct);
-
- time_remaining = wait_for_completion_timeout(&try_completion,
+ /*
+ * 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.
+ */
+ time_remaining = wait_for_completion_timeout(task_struct->vfork_done,
kunit_test_timeout());
if (time_remaining == 0) {
try_catch->try_result = -ETIMEDOUT;
@@ -92,7 +97,7 @@ void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context)
if (exit_code == -EFAULT)
try_catch->try_result = 0;
else if (exit_code == -EINTR)
- kunit_err(test, "wake_up_process() was never called\n");
+ kunit_err(test, "try faulted\n");
else if (exit_code == -ETIMEDOUT)
kunit_err(test, "try timed out\n");
else if (exit_code)