Re: [PATCH] selftests/mm: Fixed incorrect buffer->mirror size in hmm2 double_map test

[Muhammad Usama Anjum]

On 9/27/24 10:07 AM, Donet Tom wrote:
> The hmm2 double_map test was failing due to an incorrect
> buffer->mirror size. The buffer->mirror size was 6, while buffer->ptr
> size was 6 * PAGE_SIZE. The test failed because the kernel's
> copy_to_user function was attempting to copy a 6 * PAGE_SIZE buffer
> to buffer->mirror. Since the size of buffer->mirror was incorrect,
> copy_to_user failed.
> 
> This patch corrects the buffer->mirror size to 6 * PAGE_SIZE.
> 
> Test Result without this patch
> ==============================
>  #  RUN           hmm2.hmm2_device_private.double_map ...
>  # hmm-tests.c:1680:double_map:Expected ret (-14) == 0 (0)
>  # double_map: Test terminated by assertion
>  #          FAIL  hmm2.hmm2_device_private.double_map
>  not ok 53 hmm2.hmm2_device_private.double_map
> 
> Test Result with this patch
> ===========================
>  #  RUN           hmm2.hmm2_device_private.double_map ...
>  #            OK  hmm2.hmm2_device_private.double_map
>  ok 53 hmm2.hmm2_device_private.double_map
> 
> Signed-off-by: Donet Tom <donettom@xxxxxxxxxxxxx>
Please add Fixes-by tag. Other than this, LGTM

Reviewed-by: Muhammad Usama Anjum <usama.anjum@xxxxxxxxxxxxx>

> ---
>  tools/testing/selftests/mm/hmm-tests.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/mm/hmm-tests.c b/tools/testing/selftests/mm/hmm-tests.c
> index d2cfc9b494a0..141bf63cbe05 100644
> --- a/tools/testing/selftests/mm/hmm-tests.c
> +++ b/tools/testing/selftests/mm/hmm-tests.c
> @@ -1657,7 +1657,7 @@ TEST_F(hmm2, double_map)
>  
>  	buffer->fd = -1;
>  	buffer->size = size;
> -	buffer->mirror = malloc(npages);
> +	buffer->mirror = malloc(size);
>  	ASSERT_NE(buffer->mirror, NULL);
>  
>  	/* Reserve a range of addresses. */

-- 
BR,
Muhammad Usama Anjum