Re: [PATCH v2] mm/gup: honour FOLL_PIN in NOMMU __get_user_pages_locked()

["David Hildenbrand (Arm)" <david@kernel.org>]

On 5/27/26 02:35, Andrew Morton wrote:
> On Fri, 24 Apr 2026 16:19:32 +0200 "David Hildenbrand (Arm)" <david@kernel.org> wrote:
> 
>> On 4/24/26 15:38, Andrew Morton wrote:
>>>
>>>
>>> Battle of the bots?
>>> 	https://sashiko.dev/#/patchset/2026042303-vendor-outright-b9d2@gregkh
>>
>> It references the
>>
>> 	if (pages && !(flags & FOLL_PIN))
>> 		flags |= FOLL_GET;
>>
>> I'm not sure if there is actual NOMMU code that triggers it. For example,
>> uprobes uses that pattern, but I suspect that that's not a thing on NOMMU.
>>
>>
>> Probably best to just squash:
>>
>> diff --git a/mm/gup.c b/mm/gup.c
>> index ad9ded39609c..44bd28cf6e00 100644
>> --- a/mm/gup.c
>> +++ b/mm/gup.c
>> @@ -1988,6 +1988,9 @@ static long __get_user_pages_locked(struct mm_struct *mm,
>> unsigned long start,
>>         if (!nr_pages)
>>                 return 0;
>>
>> +       if (pages && !(foll_flags & FOLL_PIN))
>> +               foll_flags |= FOLL_GET;
>> +
>>         /*
>>          * The internal caller expects GUP to manage the lock internally and the
>>          * lock must be released when this returns.
> 
> Nothing happened.
> 
> Should we proceed with this as-is?

No let's squash what I provided. Probably a resend would be best. If greg is too
busy I can give it a try tomorrow.

-- 
Cheers,

David