[heap] Fix address space leak in Unmapper

test/unittests/heap/unmapper-unittest.cc

+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifdef __linux__
+#include <sys/mman.h>
+#undef MAP_TYPE
+#endif  // __linux__
+
+#include "src/heap/heap-inl.h"
+#include "src/heap/spaces-inl.h"
+#include "src/isolate.h"
+#include "test/unittests/test-utils.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace v8 {
+namespace internal {
+
+class SequentialUnmapperTest : public TestWithIsolate {
+ public:
+  SequentialUnmapperTest() = default;
+  ~SequentialUnmapperTest() override = default;
+
+  static void SetUpTestCase() {
+    old_flag_ = i::FLAG_concurrent_sweeping;
+    i::FLAG_concurrent_sweeping = false;
+    TestWithIsolate::SetUpTestCase();
+  }
+
+  static void TearDownTestCase() {
+    TestWithIsolate::TearDownTestCase();
+    i::FLAG_concurrent_sweeping = old_flag_;
+  }
+
+  Heap* heap() { return isolate()->heap(); }
+  MemoryAllocator* allocator() { return heap()->memory_allocator(); }
+  MemoryAllocator::Unmapper* unmapper() { return allocator()->unmapper(); }
+
+ private:
+  static bool old_flag_;
+
+  DISALLOW_COPY_AND_ASSIGN(SequentialUnmapperTest);
+};
+
+bool SequentialUnmapperTest::old_flag_;
+
+#ifdef __linux__
+
+// See v8:5945.
+TEST_F(SequentialUnmapperTest, UnmapOnTeardownAfterAlreadyFreeingPooled) {
+  Page* page =
+      allocator()->AllocatePage(MemoryAllocator::PageAreaSize(OLD_SPACE),
+                                static_cast<PagedSpace*>(heap()->old_space()),
+                                Executability::NOT_EXECUTABLE);
+  heap()->old_space()->UnlinkFreeListCategories(page);
+  EXPECT_NE(nullptr, page);
+  const int page_size = getpagesize();
+  void* start_address = static_cast<void*>(page->address());
+  EXPECT_EQ(0, msync(start_address, page_size, MS_SYNC));
+  allocator()->Free<MemoryAllocator::kPooledAndQueue>(page);
+  EXPECT_EQ(0, msync(start_address, page_size, MS_SYNC));
+  unmapper()->FreeQueuedChunks();
+  EXPECT_EQ(0, msync(start_address, page_size, MS_SYNC));
+  unmapper()->TearDown();
+  EXPECT_EQ(-1, msync(start_address, page_size, MS_SYNC));
+}
+
+// See v8:5945.
+TEST_F(SequentialUnmapperTest, UnmapOnTeardown) {
+  Page* page =
+      allocator()->AllocatePage(MemoryAllocator::PageAreaSize(OLD_SPACE),
+                                static_cast<PagedSpace*>(heap()->old_space()),
+                                Executability::NOT_EXECUTABLE);
+  heap()->old_space()->UnlinkFreeListCategories(page);
+  EXPECT_NE(nullptr, page);
+  const int page_size = getpagesize();
+  void* start_address = static_cast<void*>(page->address());
+  EXPECT_EQ(0, msync(start_address, page_size, MS_SYNC));
+  allocator()->Free<MemoryAllocator::kPooledAndQueue>(page);
+  EXPECT_EQ(0, msync(start_address, page_size, MS_SYNC));
+  unmapper()->TearDown();
+  EXPECT_EQ(-1, msync(start_address, page_size, MS_SYNC));
+}
+
+#endif  // __linux__
+
+}  // namespace internal
+}  // namespace v8