kthread_stop always returning -EINTR?

[Martin Galvan]

Still, going back to this issue: even though I made make a mistake and
incorrectly called kthread_stop on a (possibly) non-existent
task_struct, it's not clear to me why I didn't get to see the thread
function printks. If the thread function finished before reaching
kthread_stop, I should be able to see them, right? The only way I can
see them is by removing the call to kthread_stop altogether. This
makes it seem like kthread_stop kills the new thread before it gets a
chance to run, yet that goes against the description in the comments.