Axel, On Fri, Apr 22, 2022 at 02:29:41PM -0700, Axel Rasmussen wrote: > @@ -65,6 +66,8 @@ struct userfaultfd_ctx { > unsigned int flags; > /* features requested from the userspace */ > unsigned int features; > + /* whether or not to handle kernel faults */ > + bool handle_kernel_faults; Could you help explain why we need this bool? I failed to figure out myself on the difference against "!(ctx->flags & UFFD_USER_MODE_ONLY)". Thanks, -- Peter Xu