Update the VMA tests to assert that vma_flags_count() behaves as expected,
as well as vma_flags_test_single_mask() and vma_test_single_mask().

For the test functions we can simply update the existing vma_test(), et
al. test to also test the single_mask variants.

We also add some explicit testing of an empty VMA flag to this test to
ensure this is handled properly.

In order to test vma_flags_count() we simply take an existing set of flags
and gradually remove flags ensuring the count remains as expected
throughout.

We also update the vma[_flags]_test_all() tests to make clear the semantics
that we expect vma[_flags]_test_all(..., EMPTY_VMA_FLAGS) to return true,
as trivially, all flags of none are always set in VMA flags.

Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
---
 tools/testing/vma/tests/vma.c | 63 ++++++++++++++++++++++++++++++-----
 1 file changed, 54 insertions(+), 9 deletions(-)

diff --git a/tools/testing/vma/tests/vma.c b/tools/testing/vma/tests/vma.c
index 1395d55a1e02..c73c3a565f1d 100644
--- a/tools/testing/vma/tests/vma.c
+++ b/tools/testing/vma/tests/vma.c
@@ -174,10 +174,10 @@ static bool test_vma_flags_word(void)
 /* Ensure that vma_flags_test() and friends works correctly. */
 static bool test_vma_flags_test(void)
 {
-	const vma_flags_t flags = mk_vma_flags(VMA_READ_BIT, VMA_WRITE_BIT,
-					       VMA_EXEC_BIT
+	vma_flags_t flags = mk_vma_flags(VMA_READ_BIT, VMA_WRITE_BIT,
+					 VMA_EXEC_BIT
 #if NUM_VMA_FLAG_BITS > 64
-					       , 64, 65
+					 , 64, 65
 #endif
 		);
 	struct vm_area_desc desc = {
@@ -187,14 +187,18 @@ static bool test_vma_flags_test(void)
 		.flags = flags,
 	};
 
-#define do_test(_flag)					\
-	ASSERT_TRUE(vma_flags_test(&flags, _flag));	\
-	ASSERT_TRUE(vma_test(&vma, _flag));		\
+#define do_test(_flag)							    \
+	ASSERT_TRUE(vma_flags_test(&flags, _flag));			    \
+	ASSERT_TRUE(vma_flags_test_single_mask(&flags, mk_vma_flags(_flag))); \
+	ASSERT_TRUE(vma_test(&vma, _flag));				    \
+	ASSERT_TRUE(vma_test_single_mask(&vma, mk_vma_flags(_flag)));	    \
 	ASSERT_TRUE(vma_desc_test(&desc, _flag))
 
-#define do_test_false(_flag)				\
-	ASSERT_FALSE(vma_flags_test(&flags, _flag));	\
-	ASSERT_FALSE(vma_test(&vma, _flag));		\
+#define do_test_false(_flag)						     \
+	ASSERT_FALSE(vma_flags_test(&flags, _flag));			     \
+	ASSERT_FALSE(vma_flags_test_single_mask(&flags, mk_vma_flags(_flag))); \
+	ASSERT_FALSE(vma_test(&vma, _flag));				     \
+	ASSERT_FALSE(vma_test_single_mask(&vma, mk_vma_flags(_flag)));	     \
 	ASSERT_FALSE(vma_desc_test(&desc, _flag))
 
 	do_test(VMA_READ_BIT);
@@ -212,6 +216,15 @@ static bool test_vma_flags_test(void)
 #undef do_test
 #undef do_test_false
 
+	/* We define the _single_mask() variants to return false if empty. */
+	ASSERT_FALSE(vma_flags_test_single_mask(&flags, EMPTY_VMA_FLAGS));
+	ASSERT_FALSE(vma_test_single_mask(&vma, EMPTY_VMA_FLAGS));
+	/* Even when both flags and tested flag mask are empty! */
+	flags = EMPTY_VMA_FLAGS;
+	vma.flags = EMPTY_VMA_FLAGS;
+	ASSERT_FALSE(vma_flags_test_single_mask(&flags, EMPTY_VMA_FLAGS));
+	ASSERT_FALSE(vma_test_single_mask(&vma, EMPTY_VMA_FLAGS));
+
 	return true;
 }
 
@@ -309,6 +322,10 @@ static bool test_vma_flags_test_any(void)
 	do_test(VMA_READ_BIT, VMA_WRITE_BIT, VMA_EXEC_BIT, 64, 65);
 #endif
 
+	/* Testing all flags against none trivially succeeds. */
+	ASSERT_TRUE(vma_flags_test_all_mask(&flags, EMPTY_VMA_FLAGS));
+	ASSERT_TRUE(vma_test_all_mask(&vma, EMPTY_VMA_FLAGS));
+
 #undef do_test
 #undef do_test_all_true
 #undef do_test_all_false
@@ -592,6 +609,33 @@ static bool test_append_vma_flags(void)
 	return true;
 }
 
+/* Assert that vma_flags_count() behaves as expected. */
+static bool test_vma_flags_count(void)
+{
+	vma_flags_t flags = mk_vma_flags(VMA_READ_BIT, VMA_WRITE_BIT,
+					 VMA_EXEC_BIT
+#if NUM_VMA_FLAG_BITS > 64
+					 , 64, 65
+#endif
+		);
+
+#if NUM_VMA_FLAG_BITS > 64
+	ASSERT_EQ(vma_flags_count(&flags), 5);
+	vma_flags_clear(&flags, 64);
+	ASSERT_EQ(vma_flags_count(&flags), 4);
+	vma_flags_clear(&flags, 65);
+#endif
+	ASSERT_EQ(vma_flags_count(&flags), 3);
+	vma_flags_clear(&flags, VMA_EXEC_BIT);
+	ASSERT_EQ(vma_flags_count(&flags), 2);
+	vma_flags_clear(&flags, VMA_WRITE_BIT);
+	ASSERT_EQ(vma_flags_count(&flags), 1);
+	vma_flags_clear(&flags, VMA_READ_BIT);
+	ASSERT_EQ(vma_flags_count(&flags), 0);
+
+	return true;
+}
+
 static void run_vma_tests(int *num_tests, int *num_fail)
 {
 	TEST(copy_vma);
@@ -607,4 +651,5 @@ static void run_vma_tests(int *num_tests, int *num_fail)
 	TEST(vma_flags_diff);
 	TEST(vma_flags_and);
 	TEST(append_vma_flags);
+	TEST(vma_flags_count);
 }
-- 
2.53.0