Add tests that cover msan explicit_bzero issue

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/tests/suites/test_suite_platform_util.data b/tests/suites/test_suite_platform_util.data
index 948543a..b820293 100644
--- a/tests/suites/test_suite_platform_util.data
+++ b/tests/suites/test_suite_platform_util.data
@@ -21,3 +21,27 @@
 
 Zeroize len 128
 mbedtls_platform_zeroize:128:0
+
+Zeroize uninitialised 1 0
+mbedtls_platform_zeroize_uninitialised:1:0
+
+Zeroize uninitialised 16 0
+mbedtls_platform_zeroize_uninitialised:16:0
+
+Zeroize uninitialised 16 1
+mbedtls_platform_zeroize_uninitialised:16:1
+
+Zeroize uninitialised 16 10
+mbedtls_platform_zeroize_uninitialised:16:10
+
+Zeroize uninitialised 16 15
+mbedtls_platform_zeroize_uninitialised:16:15
+
+Zeroize uninitialised 128 0
+mbedtls_platform_zeroize_uninitialised:128:0
+
+Zeroize uninitialised 128 64
+mbedtls_platform_zeroize_uninitialised:128:64
+
+Zeroize uninitialised 128 127
+mbedtls_platform_zeroize_uninitialised:128:127
diff --git a/tests/suites/test_suite_platform_util.function b/tests/suites/test_suite_platform_util.function
index e5464e0..8f131df 100644
--- a/tests/suites/test_suite_platform_util.function
+++ b/tests/suites/test_suite_platform_util.function
@@ -39,3 +39,13 @@
     TEST_EQUAL(buf[len + 1], 2);
 }
 /* END_CASE */
+
+/* BEGIN_CASE */
+void mbedtls_platform_zeroize_uninitialised(int len, int p)
+{
+    char buf[128];
+    mbedtls_platform_zeroize(buf, len);
+
+    TEST_EQUAL(buf[p], 0);
+}
+/* END_CASE */
\ No newline at end of file