Re: [RFC] prctl: Deprecate non PR_SET_MM_MAP operations

From: Michal Hocko
Date: Wed Apr 04 2018 - 01:35:48 EST


On Tue 03-04-18 16:15:20, Yang Shi wrote:
>
>
> On 4/3/18 3:37 PM, Cyrill Gorcunov wrote:
> > An ability to manipulate mm_struct fields was introduced in
> > sake of CRIU in first place. Later we provide more suitable
> > and safe operation PR_SET_MM_MAP where all fields to be modifed
> > are passed in one structure which allows us to make more detailed
> > verification.
> >
> > Still old interface remains present for compatibility reason
> > though CRIU itself already switched to PR_SET_MM_MAP on its
> > own long ago.
> >
> > Googling didn't reveal some other users of this operation
> > so I think it should be safe to issue deprecation warning
> > first time and get rid of this interface after a couple
> > of releases.
> >
> > CC: Andrey Vagin <avagin@xxxxxxxxxx>
> > CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxx>
> > CC: Pavel Emelyanov <xemul@xxxxxxxxxxxxx>
> > CC: Michael Kerrisk <mtk.manpages@xxxxxxxxx>
> > CC: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx>
> > CC: Michal Hocko <mhocko@xxxxxxxxxx>
> > Signed-off-by: Cyrill Gorcunov <gorcunov@xxxxxxxxx>
> > ---
> > Or we can simply drop it off because PR_SET_MM_MAP covers all needs,
> > and I would rather prefer to do that asap.
>
> Thanks for making it deprecated. I'd prefer just drop it off if nobody
> objects. The change will get soaked in linux-next for a while , we will know
> if it breaks compatibility (it sounds very unlikely).

Yeah, let's just drop it and have the patch in linux-next (via mmotm)
for 2 release cycles and see whether somebody complains.

You can add
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
for such a patch.
--
Michal Hocko
SUSE Labs