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

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 [off-list ref] wrote:

quoted

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 <redacted>

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