[RFC 02/12] mm: Generalize the mprotect implementation to support extensions

[Alison Schofield]

On Mon, Sep 10, 2018 at 01:12:31PM +0300, Jarkko Sakkinen wrote:
> On Fri, 2018-09-07 at 15:34 -0700, Alison Schofield wrote:
> > Today mprotect is implemented to support legacy mprotect behavior
> > plus an extension for memory protection keys. Make it more generic
> > so that it can support additional extensions in the future.
> > 
> > This is done is preparation for adding a new system call for memory
> > encyption keys. The intent is that the new encrypted mprotect will be
> > another extension to legacy mprotect.
> > 
> > Signed-off-by: Alison Schofield <alison.schofield at intel.com>
> > ---
> >  mm/mprotect.c | 10 ++++++----
> >  1 file changed, 6 insertions(+), 4 deletions(-)
> > 
> > diff --git a/mm/mprotect.c b/mm/mprotect.c
> > index 68dc476310c0..56e64ef7931e 100644
> > --- a/mm/mprotect.c
> > +++ b/mm/mprotect.c
> > @@ -35,6 +35,8 @@
> >  
> >  #include "internal.h"
> >  
> > +#define NO_PKEY  -1
> 
> This commit does not make anything more generic but it does take
> away a magic number. The code change is senseful. The commit
> message is nonsense.

do_mprotect_ext() is intended to be the generic replacement for
do_mprotect_pkey() which was added for protection keys.

> 
> PS. Please use @linux.intel.com for LKML.
Is this a request to use your @linux.intel.com email address when I'm
posting to LKML's?

> 
> /Jarkko