Re: [RFC] prctl: Deprecate non PR_SET_MM_MAP operations

[Yang Shi]

On 4/3/18 10:35 PM, Michal Hocko wrote:
> 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.

BTW, I will do my v3 on top of the patch (drop off prctl_set_mm).

Yang

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