On Thu, Oct 19, 2017 at 02:58:17PM +0200, Jan Kara wrote: > Signed-off-by: Jan Kara <jack@xxxxxxx> > --- > man2/mmap.2 | 30 ++++++++++++++++++++++++++++++ > 1 file changed, 30 insertions(+) > > diff --git a/man2/mmap.2 b/man2/mmap.2 > index 47c3148653be..598ff0c64f7f 100644 > --- a/man2/mmap.2 > +++ b/man2/mmap.2 > @@ -125,6 +125,21 @@ are carried through to the underlying file. > to the underlying file requires the use of > .BR msync (2).) > .TP > +.B MAP_SHARED_VALIDATE > +The same as > +.B MAP_SHARED > +except that > +.B MAP_SHARED > +mappings ignore unknown flags in > +.IR flags . > +In contrast when creating mapping of > +.B MAP_SHARED_VALIDATE > +mapping type, the kernel verifies all passed flags are known and fails the > +mapping with > +.BR EOPNOTSUPP > +otherwise. This mapping type is also required to be able to use some mapping > +flags. > +.TP Some small nits: I think you should maybe include a "(since Linux 4.15)" type note after the MAP_SHARED_VALIDATE header. You also need to update the following line: Both of these flags are described in POSIX.1-2001 and POSIX.1-2008. Which used to refer to MAP_SYNC and MAP_PRIVATE.