On Wed, 1 Jun 2022 14:09:47 -0700 Axel Rasmussen <axelrasmussen@xxxxxxxxxx> wrote: > To achieve this, add a /dev/userfaultfd misc device. This device > provides an alternative to the userfaultfd(2) syscall for the creation > of new userfaultfds. The idea is, any userfaultfds created this way will > be able to handle kernel faults, without the caller having any special > capabilities. Access to this mechanism is instead restricted using e.g. > standard filesystem permissions. The use of a /dev node isn't pretty. Why can't this be done by tweaking sys_userfaultfd() or by adding a sys_userfaultfd2()? Peter, will you be completing review of this patchset?