On Thu, Aug 06, 2020 at 01:27:57PM +0300, Kirill A. Shutemov wrote: > On Tue, Aug 04, 2020 at 12:50:32PM +0300, Mike Rapoport wrote: > > From: Mike Rapoport <rppt@xxxxxxxxxxxxx> > > > > Introduce "memfd_secret" system call with the ability to create memory > > areas visible only in the context of the owning process and not mapped not > > only to other processes but in the kernel page tables as well. > > > > The user will create a file descriptor using the memfd_secret() system call > > where flags supplied as a parameter to this system call will define the > > desired protection mode for the memory associated with that file > > descriptor. Currently there are two protection modes: > > > > * exclusive - the memory area is unmapped from the kernel direct map and it > > is present only in the page tables of the owning mm. > > * uncached - the memory area is present only in the page tables of the > > owning mm and it is mapped there as uncached. > > I'm not sure why flag for exclusive mode is needed. It has to be default. > And if you want uncached on top of that set the flag. Makes sense. > What am I missing? > > -- > Kirill A. Shutemov -- Sincerely yours, Mike.
