Hi Jens,
I just found a (so far theoretical) issue with the io_uring submission offloading to workqueues or threads. We have lots of places using in_compat_syscall() to check if a syscall needs compat treatmenet. While the biggest users is iocttl(), we also have a fair amount of places using in_compat_task() in read and write methods, and these will not do the wrong thing when used with io_uring under certain conditions. I'm not sure how to best fix this, except for making sure in_compat_syscall() returns true one way or another for these cases.
