On Mon, Jan 28, 2019 at 07:26:00PM +0100, Cédric Le Goater wrote: > > Is clearing the PTEs and repopulating the VMA unsafe ? Actually, now that I come to think of it, there could be any number of VMAs (well, up to almost 64k of them), since once you have a file descriptor you can call mmap on it multiple times. The more I think about it, the more I think that getting userspace to manage the mappings with mmap() and munmap() is the right idea if it can be made to work. Paul.