On 11/24/19 1:58 AM, Pavel Begunkov wrote: > Read/write requests to devices without implemented read/write_iter > using fixed buffers causes general protection fault, which totally > hangs a machine. > > io_import_fixed() initialises iov_iter with bvec, but loop_rw_iter() > accesses it as iovec, so dereferencing random address. > > kmap() page by page in this case This looks good to me, much cleaner/simpler. I've added a few pipe fixed buffer tests to liburing as well. Didn't crash for me, but obvious garbage coming out. I've flagged this for stable as well. -- Jens Axboe