Re: [PATCH v4 5/7] mm: selftests: Add shmem into memory failure test

[David Hildenbrand (Arm)]

On 6/2/26 23:55, Lisa Wang wrote:
> Add a shmem memory failure selftest to test the shmem memory failure is
> correct after modifying shmem return value.
> 
> Specifically, test the expected behavior under various scenarios
> combining page dirtiness (dirty vs clean) and failure types (hard vs
> soft):
> + Dirty + Hard: Trigger a SIGBUS on injection, and trigger another
>   SIGBUS when reading the page again.
> + Dirty + Soft: No SIGBUS is triggered, and the original value can be
>   read successfully.
> + Clean + Hard: No SIGBUS is triggered on injection, but trigger a
>   SIGBUS when trying to read the page again.
> + Clean + Soft: No SIGBUS is triggered, and the page can be read
>   successfully.
> 
> Signed-off-by: Lisa Wang <wyihan@xxxxxxxxxx>
> ---
>  tools/testing/selftests/mm/memory-failure.c | 111 +++++++++++++++++++++++++++-
>  1 file changed, 108 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/testing/selftests/mm/memory-failure.c b/tools/testing/selftests/mm/memory-failure.c
> index 3d9e0b9ffb41..43949b3b3565 100644
> --- a/tools/testing/selftests/mm/memory-failure.c
> +++ b/tools/testing/selftests/mm/memory-failure.c
> @@ -30,9 +30,14 @@ enum result_type {
>  	MADV_HARD_ANON,
>  	MADV_HARD_CLEAN_PAGECACHE,
>  	MADV_HARD_DIRTY_PAGECACHE,
> +	MADV_HARD_CLEAN_SHMEM,
> +	MADV_HARD_DIRTY_SHMEM,
>  	MADV_SOFT_ANON,
>  	MADV_SOFT_CLEAN_PAGECACHE,
>  	MADV_SOFT_DIRTY_PAGECACHE,
> +	MADV_SOFT_CLEAN_SHMEM,
> +	MADV_SOFT_DIRTY_SHMEM,
> +	READ_ERROR,
>  };
>  
>  static jmp_buf signal_jmp_buf;
> @@ -165,17 +170,21 @@ static void check(struct __test_metadata *_metadata, FIXTURE_DATA(memory_failure
>  	case MADV_HARD_CLEAN_PAGECACHE:
>  	case MADV_SOFT_CLEAN_PAGECACHE:
>  	case MADV_SOFT_DIRTY_PAGECACHE:
> -		/* It is not expected to receive a SIGBUS signal. */
> -		ASSERT_EQ(setjmp, 0);
> -
> +	case MADV_SOFT_DIRTY_SHMEM:
>  		/* The page content should remain unchanged. */
>  		ASSERT_TRUE(check_memory(vaddr, self->page_size));

You should likely use "fallthrough;" ... unless you are missing a break; here.



-- 
Cheers,

David