asan_region_is_poisoned

Summary: [folly] `asan_region_is_poisoned` to wrap Address Sanitizer's `__asan_region_is_poisoned`.

Reviewed By: ot, luciang, markisaa

Differential Revision: D25651040

fbshipit-source-id: 0c8f1d0203ada43746b5e2e71c1bd8b883248f68

folly/memory/SanitizeAddress.cpp

+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * 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 <folly/memory/SanitizeAddress.h>
+
+//  Address Sanitizer interface may be found at:
+//    https://github.com/llvm-mirror/compiler-rt/blob/master/include/sanitizer/asan_interface.h
+extern "C" FOLLY_ATTR_WEAK void* __asan_region_is_poisoned(void*, std::size_t);
+
+namespace folly {
+
+namespace detail {
+
+void* asan_region_is_poisoned_(void* const ptr, std::size_t len) {
+  return __asan_region_is_poisoned(ptr, len);
+}
+
+} // namespace detail
+
+} // namespace folly

folly/memory/SanitizeAddress.h

+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * 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.
+ */
+
+#pragma once
+
+#include <folly/Portability.h>
+
+namespace folly {
+
+namespace detail {
+
+void* asan_region_is_poisoned_(void* ptr, std::size_t len);
+
+}
+
+//  asan_region_is_poisoned
+//
+//  mimic: __asan_region_is_poisoned, llvm compiler-rt
+//
+//  Returns the address of the first byte in the region known to be poisoned,
+//  or nullptr if there is no such byte. If Address Sanitizer is unavailable,
+//  always returns nullptr.
+FOLLY_ALWAYS_INLINE static void* asan_region_is_poisoned(
+    void* const ptr,
+    std::size_t const len) {
+  return kIsSanitizeAddress //
+      ? detail::asan_region_is_poisoned_(ptr, len)
+      : nullptr;
+}
+
+} // namespace folly

folly/memory/test/SanitizeAddressTest.cpp

+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * 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 <folly/memory/SanitizeAddress.h>
+
+#include <folly/portability/GTest.h>
+
+class SanitizeAddressTest : public testing::Test {};
+
+TEST_F(SanitizeAddressTest, asan_region_is_poisoned) {
+  auto data = malloc(4096);
+  EXPECT_EQ(nullptr, folly::asan_region_is_poisoned(data, 4096));
+  free(data);
+  EXPECT_EQ(
+      folly::kIsSanitizeAddress ? data : nullptr,
+      folly::asan_region_is_poisoned(data, 4096));
+}