Re: [PATCH] selftests/ring-buffer: Add test for out-of-bound pgoff mapping

[Steven Rostedt <rostedt@goodmis.org>]

Hi Shuah,

Care to take this through your tree?

On Wed, 18 Dec 2024 17:03:18 +0000
Vincent Donnefort <vdonnefort@google.com> wrote:

> Extend the ring-buffer mapping test coverage by checking an out-of-bound
> pgoff which has proven to be problematic in the past.
> 
> Cc: Shuah Khan <skhan@linuxfoundation.org>
> Cc: linux-kselftest@vger.kernel.org
> Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
> 
> diff --git a/tools/testing/selftests/ring-buffer/map_test.c b/tools/testing/selftests/ring-buffer/map_test.c
> index d10a847130fb..a58f520f2f41 100644
> --- a/tools/testing/selftests/ring-buffer/map_test.c
> +++ b/tools/testing/selftests/ring-buffer/map_test.c
> @@ -233,12 +233,18 @@ TEST_F(map, data_mmap)
>  	ASSERT_NE(data, MAP_FAILED);
>  	munmap(data, data_len);
>  
> -	/* Overflow the available subbufs by 1 */
> +	/* Offset within ring-buffer bounds, mapping size overflow */
>  	meta_len += desc->meta->subbuf_size * 2;
>  	data = mmap(NULL, data_len, PROT_READ, MAP_SHARED,
>  		    desc->cpu_fd, meta_len);
>  	ASSERT_EQ(data, MAP_FAILED);
>  
> +	/* Offset outside ring-buffer bounds */
> +	data_len = desc->meta->subbuf_size * desc->meta->nr_subbufs;
> +	data = mmap(NULL, data_len, PROT_READ, MAP_SHARED,
> +		    desc->cpu_fd, data_len + (desc->meta->subbuf_size * 2));
> +	ASSERT_EQ(data, MAP_FAILED);
> +
>  	/* Verify meta-page padding */
>  	if (desc->meta->meta_page_size > getpagesize()) {
>  		data_len = desc->meta->meta_page_size;
> 
> base-commit: 61baee2dc5341c936e7fa7b1ca33c5607868de69

You can ignore the above "base-commit" (I don't have it), as it applies
fine to v6.13-rc4.

-- Steve