Re: [PATCH v3 2/2] selftests/mm: add tests for UFFDIO_MOVE of a uffd-protected swap entry

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

On 9/28/26 10:53, David Hildenbrand (Arm) wrote:
> On 9/26/26 14:41, Donggeun Yoo wrote:
>> Move a swapped-out page out of a write-protected or RWP-protected area into
>> a destination registered for missing faults only, and read pagemap bit 57
>> at the destination.  The destination was never protected, so the bit must
>> be clear.
>>
>> Assisted-by: LLM
>> Signed-off-by: Donggeun Yoo <donggeunyoo.kernel@gmail.com>
>> ---
>>  tools/testing/selftests/mm/uffd-unit-tests.c | 84 ++++++++++++++++++++
>>  1 file changed, 84 insertions(+)
>>
>> diff --git a/tools/testing/selftests/mm/uffd-unit-tests.c b/tools/testing/selftests/mm/uffd-unit-tests.c
>> index ef9b3956bdcfd..580178630eded 100644
>> --- a/tools/testing/selftests/mm/uffd-unit-tests.c
>> +++ b/tools/testing/selftests/mm/uffd-unit-tests.c
>> @@ -2037,6 +2037,75 @@ static void uffd_move_pmd_split_test(uffd_global_test_opts_t *gopts, uffd_test_a
>>  			      uffd_move_pmd_handle_fault);
>>  }
>>  
>> +/*
>> + * Moving a swapped-out page out of a write-protected or RWP-protected area
>> + * must not carry the uffd bit into a destination registered for missing
>> + * faults only: such a bit is never cleared afterwards, so pagemap keeps
>> + * reporting the page as uffd-tracked.
>> + *
>> + * Needs a swap device; skipped if MADV_PAGEOUT cannot evict the page.
>> + */
>> +static void uffd_move_swap_test_common(uffd_global_test_opts_t *gopts,
>> +				       bool rwp)
>> +{
>> +	unsigned long page_size = gopts->page_size;
>> +	struct uffdio_move move = { };
>> +	int pagemap_fd;
>> +
>> +	if (rwp) {
>> +		if (uffd_register_rwp(gopts->uffd, gopts->area_src, page_size))
>> +			err("register src failure");
>> +	} else if (uffd_register(gopts->uffd, gopts->area_src, page_size,
>> +				 false, true, false)) {
>> +		err("register src failure");
>> +	}
> 
> if ()

Clicked sent by accident ... let me reply once more.

-- 
Cheers,

David