Add LsanVirtualAddressSpace implementation

When leak sanitizer is active, an LsanVirtualAddressSpace is used and
takes care of marking the allocated pages as lsan root regions.

Bug: chromium:1276767
Change-Id: I3d8a61f7d3c59e4574e46707d2217031a32e3f0e
Cq-Include-Trybots: luci.v8.try:v8_linux64_heap_sandbox_dbg_ng,v8_linux_arm64_sim_heap_sandbox_dbg_ng
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3314828
Commit-Queue: Samuel Groß <saelo@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78251}

BUILD.bazel

@@ -1926,6 +1926,8 @@ filegroup(
         "src/base/sanitizer/asan.h",
         "src/base/sanitizer/lsan-page-allocator.cc",
         "src/base/sanitizer/lsan-page-allocator.h",
+        "src/base/sanitizer/lsan-virtual-address-space.cc",
+        "src/base/sanitizer/lsan-virtual-address-space.h",
         "src/base/sanitizer/msan.h",
         "src/base/sanitizer/tsan.h",
         "src/snapshot/code-serializer.cc",

BUILD.gn

@@ -5040,6 +5040,8 @@ v8_component("v8_libbase") {
     "src/base/sanitizer/asan.h",
     "src/base/sanitizer/lsan-page-allocator.cc",
     "src/base/sanitizer/lsan-page-allocator.h",
+    "src/base/sanitizer/lsan-virtual-address-space.cc",
+    "src/base/sanitizer/lsan-virtual-address-space.h",
     "src/base/sanitizer/lsan.h",
     "src/base/sanitizer/msan.h",
     "src/base/sanitizer/tsan.h",

src/base/sanitizer/lsan-virtual-address-space.cc

@@ -0,0 +1,61 @@
+// Copyright 2021 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.
+
+#include "src/base/sanitizer/lsan-virtual-address-space.h"
+
+#include "include/v8-platform.h"
+#include "src/base/logging.h"
+
+#if defined(LEAK_SANITIZER)
+#include <sanitizer/lsan_interface.h>
+#endif
+
+namespace v8 {
+namespace base {
+
+LsanVirtualAddressSpace::LsanVirtualAddressSpace(
+    std::unique_ptr<v8::VirtualAddressSpace> vas)
+    : VirtualAddressSpace(vas->page_size(), vas->allocation_granularity(),
+                          vas->base(), vas->size()),
+      vas_(std::move(vas)) {
+  DCHECK_NOT_NULL(vas_);
+}
+
+Address LsanVirtualAddressSpace::AllocatePages(Address hint, size_t size,
+                                               size_t alignment,
+                                               PagePermissions permissions) {
+  Address result = vas_->AllocatePages(hint, size, alignment, permissions);
+#if defined(LEAK_SANITIZER)
+  if (result != 0) {
+    __lsan_register_root_region(reinterpret_cast<void*>(result), size);
+  }
+#endif  // defined(LEAK_SANITIZER)
+  return result;
+}
+
+bool LsanVirtualAddressSpace::FreePages(Address address, size_t size) {
+  bool result = vas_->FreePages(address, size);
+#if defined(LEAK_SANITIZER)
+  if (result) {
+    __lsan_unregister_root_region(reinterpret_cast<void*>(address), size);
+  }
+#endif  // defined(LEAK_SANITIZER)
+  return result;
+}
+
+std::unique_ptr<VirtualAddressSpace> LsanVirtualAddressSpace::AllocateSubspace(
+    Address hint, size_t size, size_t alignment,
+    PagePermissions max_permissions) {
+  auto subspace =
+      vas_->AllocateSubspace(hint, size, alignment, max_permissions);
+#if defined(LEAK_SANITIZER)
+  if (subspace) {
+    subspace = std::make_unique<LsanVirtualAddressSpace>(std::move(subspace));
+  }
+#endif  // defined(LEAK_SANITIZER)
+  return subspace;
+}
+
+}  // namespace base
+}  // namespace v8

src/base/sanitizer/lsan-virtual-address-space.h

@@ -0,0 +1,63 @@
+// Copyright 2021 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.
+
+#ifndef V8_BASE_SANITIZER_LSAN_VIRTUAL_ADDRESS_SPACE_H_
+#define V8_BASE_SANITIZER_LSAN_VIRTUAL_ADDRESS_SPACE_H_
+
+#include "include/v8-platform.h"
+#include "src/base/base-export.h"
+#include "src/base/compiler-specific.h"
+
+namespace v8 {
+namespace base {
+
+using Address = uintptr_t;
+
+// This is a v8::VirtualAddressSpace implementation that decorates provided page
+// allocator object with leak sanitizer notifications when LEAK_SANITIZER is
+// defined.
+class V8_BASE_EXPORT LsanVirtualAddressSpace final
+    : public v8::VirtualAddressSpace {
+ public:
+  explicit LsanVirtualAddressSpace(
+      std::unique_ptr<v8::VirtualAddressSpace> vas);
+  ~LsanVirtualAddressSpace() override = default;
+
+  void SetRandomSeed(int64_t seed) override {
+    return vas_->SetRandomSeed(seed);
+  }
+
+  Address RandomPageAddress() override { return vas_->RandomPageAddress(); }
+
+  Address AllocatePages(Address hint, size_t size, size_t alignment,
+                        PagePermissions permissions) override;
+
+  bool FreePages(Address address, size_t size) override;
+
+  bool SetPagePermissions(Address address, size_t size,
+                          PagePermissions permissions) override {
+    return vas_->SetPagePermissions(address, size, permissions);
+  }
+
+  bool CanAllocateSubspaces() override { return vas_->CanAllocateSubspaces(); }
+
+  std::unique_ptr<VirtualAddressSpace> AllocateSubspace(
+      Address hint, size_t size, size_t alignment,
+      PagePermissions max_permissions) override;
+
+  bool DiscardSystemPages(Address address, size_t size) override {
+    return vas_->DiscardSystemPages(address, size);
+  }
+
+  bool DecommitPages(Address address, size_t size) override {
+    return vas_->DecommitPages(address, size);
+  }
+
+ private:
+  std::unique_ptr<v8::VirtualAddressSpace> vas_;
+};
+
+}  // namespace base
+}  // namespace v8
+#endif  // V8_BASE_SANITIZER_LSAN_VIRTUAL_ADDRESS_SPACE_H_

src/utils/allocation.cc

@@ -14,6 +14,7 @@
 #include "src/base/platform/platform.h"
 #include "src/base/platform/wrappers.h"
 #include "src/base/sanitizer/lsan-page-allocator.h"
+#include "src/base/sanitizer/lsan-virtual-address-space.h"
 #include "src/base/vector.h"
 #include "src/base/virtual-address-space.h"
 #include "src/flags/flags.h"
@@ -86,7 +87,12 @@ v8::PageAllocator* GetPlatformPageAllocator() {
 }
 
 v8::VirtualAddressSpace* GetPlatformVirtualAddressSpace() {
+#if defined(LEAK_SANITIZER)
+  static base::LeakyObject<base::LsanVirtualAddressSpace> vas(
+      std::make_unique<base::VirtualAddressSpace>());
+#else
   static base::LeakyObject<base::VirtualAddressSpace> vas;
+#endif
   return vas.get();
 }