Add some MTE-related helpers.
mte_supported() lets code efficiently detect the presence of MTE, and
ScopedDisableMTE lets code disable MTE RAII-style in a particular region
of code.
Bug: 135772972
Change-Id: I628a054b50d79f67f39f35d44232b7a2ae166afb
diff --git a/tests/mte_test.cpp b/tests/mte_test.cpp
new file mode 100644
index 0000000..2f922a2
--- /dev/null
+++ b/tests/mte_test.cpp
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <gtest/gtest.h>
+
+#include <bionic/mte.h>
+
+__attribute__((no_sanitize("hwaddress")))
+static void test_tag_mismatch() {
+ ScopedDisableMTE x;
+#if defined(__aarch64__)
+ std::unique_ptr<int[]> p = std::make_unique<int[]>(4);
+ p[0] = 1;
+ int* mistagged_p = reinterpret_cast<int*>(reinterpret_cast<uintptr_t>(p.get()) + (1ULL << 56));
+ volatile int load = *mistagged_p;
+ (void)load;
+#endif
+}
+
+TEST(mte_test, ScopedDisableMTE) {
+ test_tag_mismatch();
+}