On Tue, Dec 12, 2017 at 10:00:08AM -0800, Andy Lutomirski wrote: > On Tue, Dec 12, 2017 at 9:32 AM, Thomas Gleixner <t...@linutronix.de> wrote: > > From: Peter Zijstra <pet...@infradead.org> > > > > In order to create VMAs that are not accessible to userspace create a new > > VM_NOUSER flag. This can be used in conjunction with > > install_special_mapping() to inject 'kernel' data into the userspace map. > > > > Similar to how arch_vm_get_page_prot() allows adding _PAGE_flags to > > pgprot_t, introduce arch_vm_get_page_prot_excl() which masks > > _PAGE_flags from pgprot_t and use this to implement VM_NOUSER for x86. > > How does this interact with get_user_pages(), etc?
gup would find the page. These patches do in fact rely on that through the populate things.
