On 7/20/20 12:10 AM, Christoph Hellwig wrote: > 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. We can probably propagate this information in the io_kiocb via a flag, and have the io-wq worker set TS_COMPAT if that's the case. -- Jens Axboe
