* Brian Geffon: > Hi Florian, > copy_vma will make a copy of the existing VMA leaving the old VMA > unchanged, so the source keeps its existing protections, this is what > makes it very useful along with userfaultfd. I see. On the other hand, it's impossible to get the PROT_NONE behavior by a subsequent mprotect call because the mremap has to fail in some cases in vm.overcommit_memory=2 mode. But maybe that other behavior can be provided with a different flag if it turns out to be useful in the future. Thanks, Florian