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

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

[Vincent Donnefort]

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
-- 
2.47.1.613.gc27f4b7a9f-goog

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

[Steven Rostedt]

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

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

[Shuah Khan]

On 12/23/24 20:05, Steven Rostedt wrote:
> 
> 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.
> 

Applied to linux_kselftest next for Linux 6.14-rc1.

thanks,
-- Shuah