On Tue, Mar 12, 2019 at 08:58:30AM +0200, Mike Rapoport wrote: [...] > > +config USERFAULTFD_UNPRIVILEGED_DEFAULT > > + string "Default behavior for unprivileged userfault syscalls" > > + depends on USERFAULTFD > > + default "disabled" > > + help > > + Set this to "enabled" to allow userfaultfd syscalls from > > + unprivileged users. Set this to "disabled" to forbid > > + userfaultfd syscalls from unprivileged users. Set this to > > + "kvm" to forbid unpriviledged users but still allow users > > + who had enough permission to open /dev/kvm. > > I'd phrase it a bit differently: > > This option controls privilege level required to execute userfaultfd ^ +---- add " the default"? > system call. > > Set this to "enabled" to allow userfaultfd system call from unprivileged > users. > Set this to "disabled" to allow userfaultfd system call only for users who > have ptrace capability. > Set this to "kvm" to restrict userfaultfd system call usage to users with ^ add " who have ptrace capability, or" -------+ > permissions to open "/dev/kvm". I think your version is better than mine, but I'd like to confirm about above two extra changes before I squash them into the patch. :) Thanks! -- Peter Xu