Re: [RFC] prctl: Deprecate non PR_SET_MM_MAP operations

[Yang Shi <yang.shi@linux.alibaba.com>]

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@openvz.org>
>>> CC: Andrew Morton <akpm@linuxfoundation.org>
>>> CC: Pavel Emelyanov <xemul@virtuozzo.com>
>>> CC: Michael Kerrisk <mtk.manpages@gmail.com>
>>> CC: Yang Shi <yang.shi@linux.alibaba.com>
>>> CC: Michal Hocko <mhocko@kernel.org>
>>> Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
>>> ---
>>> 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@suse.com>
> for such a patch.