Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

10 files changed, 1842 insertions, 0 deletions

diff --git a/security/sandbox/common/test/PSandboxTesting.ipdl b/security/sandbox/common/test/PSandboxTesting.ipdl
new file mode 100644
index 0000000000..8498f4a235
--- /dev/null
+++ b/security/sandbox/common/test/PSandboxTesting.ipdl
@@ -0,0 +1,20 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+namespace mozilla {
+
+sync protocol PSandboxTesting {
+parent:
+  async ReportTestResults(nsCString testName, bool passed, nsCString message);
+  async TestCompleted();
+
+  sync GetSpecialDirectory(nsCString aSpecialDirName) returns (nsString aDirPath);
+
+child:
+  async ShutDown();
+};
+
+} //namespace mozilla
diff --git a/security/sandbox/common/test/SandboxTest.cpp b/security/sandbox/common/test/SandboxTest.cpp
new file mode 100644
index 0000000000..0f1aa6c784
--- /dev/null
+++ b/security/sandbox/common/test/SandboxTest.cpp
@@ -0,0 +1,362 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+#include "SandboxTest.h"
+
+#include "mozilla/Components.h"
+#include "mozilla/Preferences.h"
+#include "SandboxTestingParent.h"
+#include "SandboxTestingChild.h"
+#include "mozilla/dom/ContentParent.h"
+#include "mozilla/gfx/GPUProcessManager.h"
+#include "mozilla/gfx/GPUChild.h"
+#include "mozilla/net/SocketProcessParent.h"
+#include "mozilla/RDDProcessManager.h"
+#include "mozilla/RDDChild.h"
+#include "mozilla/ipc/UtilityProcessManager.h"
+#include "mozilla/ipc/UtilityProcessParent.h"
+#include "mozilla/ipc/UtilityProcessSandboxing.h"
+#include "GMPService.h"
+#include "mozilla/gmp/GMPTypes.h"
+#include "mozilla/ipc/Endpoint.h"
+#include "nsIOService.h"
+
+#ifdef XP_WIN
+#  include "nsAppDirectoryServiceDefs.h"
+#endif
+
+using namespace mozilla;
+using namespace mozilla::ipc;
+using namespace mozilla::dom;
+
+namespace mozilla {
+
+NS_IMPL_ISUPPORTS(SandboxTest, mozISandboxTest)
+
+inline void UnsetEnvVariable(const nsCString& aEnvVarName) {
+  nsCString aEnvVarNameFull = aEnvVarName + "="_ns;
+  int rv_unset =
+#ifdef XP_UNIX
+      unsetenv(aEnvVarName.get());
+#endif  // XP_UNIX
+#ifdef XP_WIN
+  _putenv(aEnvVarNameFull.get());
+#endif  // XP_WIN
+  MOZ_ASSERT(rv_unset == 0, "Error unsetting env var");
+}
+
+GeckoProcessType GeckoProcessStringToType(const nsCString& aString) {
+  for (GeckoProcessType type = GeckoProcessType(0);
+       type < GeckoProcessType::GeckoProcessType_End;
+       type = GeckoProcessType(type + 1)) {
+    if (aString == XRE_GeckoProcessTypeToString(type)) {
+      return type;
+    }
+  }
+  return GeckoProcessType::GeckoProcessType_Invalid;
+}
+
+// Set up tests on remote process connected to the given actor.
+// The actor must handle the InitSandboxTesting message.
+template <typename Actor>
+void InitializeSandboxTestingActors(
+    Actor* aActor,
+    const RefPtr<SandboxTest::ProcessPromise::Private>& aProcessPromise) {
+  MOZ_ASSERT(aActor, "Should have provided an IPC actor");
+  Endpoint<PSandboxTestingParent> sandboxTestingParentEnd;
+  Endpoint<PSandboxTestingChild> sandboxTestingChildEnd;
+  nsresult rv = PSandboxTesting::CreateEndpoints(&sandboxTestingParentEnd,
+                                                 &sandboxTestingChildEnd);
+  if (NS_FAILED(rv)) {
+    aProcessPromise->Reject(NS_ERROR_FAILURE, __func__);
+    return;
+  }
+
+  // GMPlugin binds us to the GMP Thread, so we need IPC's Send to be done on
+  // the same thread
+  Unused << aActor->SendInitSandboxTesting(std::move(sandboxTestingChildEnd));
+  // But then the SandboxTestingParent::Create() call needs to be on the main
+  // thread
+  NS_DispatchToMainThread(NS_NewRunnableFunction(
+      "SandboxTestingParent::Create",
+      [stpE = std::move(sandboxTestingParentEnd), aProcessPromise]() mutable {
+        return aProcessPromise->Resolve(
+            SandboxTestingParent::Create(std::move(stpE)), __func__);
+      }));
+}
+
+NS_IMETHODIMP
+SandboxTest::StartTests(const nsTArray<nsCString>& aProcessesList) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+#if defined(XP_WIN)
+  nsCOMPtr<nsIFile> testFile;
+  NS_GetSpecialDirectory(NS_APP_USER_PROFILE_50_DIR, getter_AddRefs(testFile));
+  MOZ_ASSERT(testFile);
+  nsCOMPtr<nsIFile> testChromeFile;
+  testFile->Clone(getter_AddRefs(testChromeFile));
+  testChromeFile->Append(u"chrome"_ns);
+  testChromeFile->Exists(&mChromeDirExisted);
+  testFile->Append(u"sandboxTest.txt"_ns);
+  testChromeFile->Append(u"sandboxTest.txt"_ns);
+  MOZ_ALWAYS_SUCCEEDS(testFile->Create(nsIFile::NORMAL_FILE_TYPE, 0666));
+  MOZ_ALWAYS_SUCCEEDS(testChromeFile->Create(nsIFile::NORMAL_FILE_TYPE, 0666));
+#endif
+
+  for (const auto& processTypeName : aProcessesList) {
+    SandboxingKind sandboxingKind = SandboxingKind::COUNT;
+    GeckoProcessType type = GeckoProcessType::GeckoProcessType_Invalid;
+    if (processTypeName.Find(":") != kNotFound) {
+      int32_t pos = processTypeName.Find(":");
+      nsCString processType = nsCString(Substring(processTypeName, 0, pos));
+      nsCString sandboxKindStr = nsCString(
+          Substring(processTypeName, pos + 1, processTypeName.Length()));
+
+      nsresult err;
+      uint64_t sbVal = (uint64_t)(sandboxKindStr.ToDouble(&err));
+      if (NS_FAILED(err)) {
+        NS_WARNING("Unable to get SandboxingKind");
+        return NS_ERROR_ILLEGAL_VALUE;
+      }
+
+      if (sbVal >= SandboxingKind::COUNT) {
+        NS_WARNING("Invalid sandboxing kind");
+        return NS_ERROR_ILLEGAL_VALUE;
+      }
+
+      if (!processType.Equals(
+              XRE_GeckoProcessTypeToString(GeckoProcessType_Utility))) {
+        NS_WARNING("Expected utility process type");
+        return NS_ERROR_ILLEGAL_VALUE;
+      }
+
+      sandboxingKind = (SandboxingKind)sbVal;
+      type = GeckoProcessType_Utility;
+    } else {
+      type = GeckoProcessStringToType(processTypeName);
+
+      if (type == GeckoProcessType::GeckoProcessType_Invalid) {
+        NS_WARNING("Invalid process type");
+        return NS_ERROR_ILLEGAL_VALUE;
+      }
+    }
+
+    RefPtr<ProcessPromise::Private> processPromise =
+        MakeRefPtr<ProcessPromise::Private>(__func__);
+
+    switch (type) {
+      case GeckoProcessType_Content: {
+        nsTArray<ContentParent*> parents;
+        ContentParent::GetAll(parents);
+        if (parents[0]) {
+          InitializeSandboxTestingActors(parents[0], processPromise);
+        } else {
+          processPromise->Reject(NS_ERROR_FAILURE, __func__);
+          MOZ_ASSERT_UNREACHABLE("SandboxTest; failure to get Content process");
+        }
+        break;
+      }
+
+      case GeckoProcessType_GPU: {
+        gfx::GPUProcessManager* gpuProc = gfx::GPUProcessManager::Get();
+        gfx::GPUChild* gpuChild = gpuProc ? gpuProc->GetGPUChild() : nullptr;
+        if (gpuChild) {
+          InitializeSandboxTestingActors(gpuChild, processPromise);
+        } else {
+          processPromise->Reject(NS_OK, __func__);
+        }
+        break;
+      }
+
+      case GeckoProcessType_RDD: {
+        RDDProcessManager* rddProc = RDDProcessManager::Get();
+        rddProc->LaunchRDDProcess()->Then(
+            GetMainThreadSerialEventTarget(), __func__,
+            [processPromise, rddProc]() {
+              RDDChild* rddChild = rddProc ? rddProc->GetRDDChild() : nullptr;
+              if (rddChild) {
+                return InitializeSandboxTestingActors(rddChild, processPromise);
+              }
+              return processPromise->Reject(NS_ERROR_FAILURE, __func__);
+            },
+            [processPromise](nsresult aError) {
+              MOZ_ASSERT_UNREACHABLE("SandboxTest; failure to get RDD process");
+              return processPromise->Reject(aError, __func__);
+            });
+        break;
+      }
+
+      case GeckoProcessType_GMPlugin: {
+        UnsetEnvVariable("MOZ_DISABLE_GMP_SANDBOX"_ns);
+        RefPtr<gmp::GeckoMediaPluginService> service =
+            gmp::GeckoMediaPluginService::GetGeckoMediaPluginService();
+        MOZ_ASSERT(service, "We have a GeckoMediaPluginService");
+
+        RefPtr<SandboxTest> self = this;
+        nsCOMPtr<nsISerialEventTarget> thread = service->GetGMPThread();
+        nsresult rv = thread->Dispatch(NS_NewRunnableFunction(
+            "SandboxTest::GMPlugin", [self, processPromise, service, thread]() {
+              service->GetContentParentForTest()->Then(
+                  thread, __func__,
+                  [self, processPromise](
+                      const RefPtr<gmp::GMPContentParent::CloseBlocker>&
+                          wrapper) {
+                    RefPtr<gmp::GMPContentParent> parent = wrapper->mParent;
+                    MOZ_ASSERT(parent,
+                               "Wrapper should wrap a valid parent if we're in "
+                               "this path.");
+                    if (!parent) {
+                      return processPromise->Reject(NS_ERROR_ILLEGAL_VALUE,
+                                                    __func__);
+                    }
+                    NS_DispatchToMainThread(NS_NewRunnableFunction(
+                        "SandboxTesting::Wrapper", [self, wrapper]() {
+                          self->mGMPContentParentWrapper = wrapper;
+                        }));
+                    return InitializeSandboxTestingActors(parent.get(),
+                                                          processPromise);
+                  },
+                  [processPromise](const MediaResult& rv) {
+                    return processPromise->Reject(NS_ERROR_FAILURE, __func__);
+                  });
+            }));
+        NS_ENSURE_SUCCESS(rv, rv);
+        break;
+      }
+
+      case GeckoProcessType_Socket: {
+        // mochitest harness force this variable, but we actually do not want
+        // that
+        UnsetEnvVariable("MOZ_DISABLE_SOCKET_PROCESS"_ns);
+
+        nsresult rv_pref =
+            Preferences::SetBool("network.process.enabled", true);
+        MOZ_ASSERT(rv_pref == NS_OK, "Error enforcing pref");
+
+        MOZ_ASSERT(net::gIOService, "No gIOService?");
+
+        net::gIOService->CallOrWaitForSocketProcess([processPromise]() {
+          // If socket process was previously disabled by env,
+          // nsIOService code will take some time before it creates the new
+          // process and it triggers this callback
+          net::SocketProcessParent* parent =
+              net::SocketProcessParent::GetSingleton();
+          if (parent) {
+            return InitializeSandboxTestingActors(parent, processPromise);
+          }
+          return processPromise->Reject(NS_ERROR_FAILURE, __func__);
+        });
+        break;
+      }
+
+      case GeckoProcessType_Utility: {
+        RefPtr<UtilityProcessManager> utilityProc =
+            UtilityProcessManager::GetSingleton();
+        utilityProc->LaunchProcess(sandboxingKind)
+            ->Then(
+                GetMainThreadSerialEventTarget(), __func__,
+                [processPromise, utilityProc, sandboxingKind]() {
+                  RefPtr<UtilityProcessParent> utilityParent =
+                      utilityProc
+                          ? utilityProc->GetProcessParent(sandboxingKind)
+                          : nullptr;
+                  if (utilityParent) {
+                    return InitializeSandboxTestingActors(utilityParent.get(),
+                                                          processPromise);
+                  }
+                  return processPromise->Reject(NS_ERROR_FAILURE, __func__);
+                },
+                [processPromise](nsresult aError) {
+                  MOZ_ASSERT_UNREACHABLE(
+                      "SandboxTest; failure to get Utility process");
+                  return processPromise->Reject(aError, __func__);
+                });
+        break;
+      }
+
+      default:
+        MOZ_ASSERT_UNREACHABLE(
+            "SandboxTest does not yet support this process type");
+        return NS_ERROR_NOT_IMPLEMENTED;
+    }
+
+    RefPtr<SandboxTest> self = this;
+    RefPtr<ProcessPromise> aPromise(processPromise);
+    aPromise->Then(
+        GetMainThreadSerialEventTarget(), __func__,
+        [self](RefPtr<SandboxTestingParent> aValue) {
+          self->mSandboxTestingParents.AppendElement(std::move(aValue));
+          return NS_OK;
+        },
+        [](nsresult aError) {
+          if (aError == NS_OK) {
+            // There is no such process for this OS.  Report test done.
+            nsCOMPtr<nsIObserverService> observerService =
+                mozilla::services::GetObserverService();
+            MOZ_RELEASE_ASSERT(observerService);
+            observerService->NotifyObservers(nullptr, "sandbox-test-done",
+                                             nullptr);
+            return NS_OK;
+          }
+          MOZ_ASSERT_UNREACHABLE("SandboxTest; failure to get a process");
+          return NS_ERROR_FAILURE;
+        });
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+SandboxTest::FinishTests() {
+  if (mGMPContentParentWrapper) {
+    RefPtr<gmp::GeckoMediaPluginService> service =
+        gmp::GeckoMediaPluginService::GetGeckoMediaPluginService();
+    MOZ_ASSERT(service, "We have a GeckoMediaPluginService");
+
+    nsCOMPtr<nsISerialEventTarget> thread = service->GetGMPThread();
+    nsresult rv = thread->Dispatch(NS_NewRunnableFunction(
+        "SandboxTest::FinishTests",
+        [wrapper = std::move(mGMPContentParentWrapper)]() {
+          // Release mGMPContentWrapper's reference. We hold this to keep an
+          // active reference on the CloseBlocker produced by GMPService,
+          // otherwise it would automatically shutdown the GMPlugin thread we
+          // started.
+          // If somehow it does not work as expected, then tests will fail
+          // because of leaks happening on GMPService and others.
+        }));
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  for (RefPtr<SandboxTestingParent>& stp : mSandboxTestingParents) {
+    SandboxTestingParent::Destroy(stp.forget());
+  }
+
+  // Make sure there is no leftover for test --verify to run without failure
+  mSandboxTestingParents.Clear();
+
+#if defined(XP_WIN)
+  nsCOMPtr<nsIFile> testFile;
+  NS_GetSpecialDirectory(NS_APP_USER_PROFILE_50_DIR, getter_AddRefs(testFile));
+  MOZ_ASSERT(testFile);
+  nsCOMPtr<nsIFile> testChromeFile;
+  testFile->Clone(getter_AddRefs(testChromeFile));
+  testChromeFile->Append(u"chrome"_ns);
+  testFile->Append(u"sandboxTest.txt"_ns);
+  if (mChromeDirExisted) {
+    // Chrome dir existed, just delete test file.
+    testChromeFile->Append(u"sandboxTest.txt"_ns);
+  }
+  testFile->Remove(false);
+  testChromeFile->Remove(true);
+#endif
+
+  return NS_OK;
+}
+
+}  // namespace mozilla
+
+NS_IMPL_COMPONENT_FACTORY(mozISandboxTest) {
+  return MakeAndAddRef<SandboxTest>().downcast<nsISupports>();
+}
diff --git a/security/sandbox/common/test/SandboxTest.h b/security/sandbox/common/test/SandboxTest.h
new file mode 100644
index 0000000000..1d8c18c4b8
--- /dev/null
+++ b/security/sandbox/common/test/SandboxTest.h
@@ -0,0 +1,45 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+#ifndef mozilla_SandboxTest_h
+#define mozilla_SandboxTest_h
+
+#include "SandboxTestingParent.h"
+#include "mozISandboxTest.h"
+#include "mozilla/GfxMessageUtils.h"
+#include "mozilla/MozPromise.h"
+#include "GMPService.h"
+#include "nsTArray.h"
+
+#if !defined(MOZ_DEBUG) || !defined(ENABLE_TESTS)
+#  error "This file should not be used outside of debug with tests"
+#endif
+
+namespace mozilla {
+
+class SandboxTest : public mozISandboxTest {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_MOZISANDBOXTEST
+
+  SandboxTest() : mSandboxTestingParents{nullptr} {};
+
+  // We allow nsresult to be rejected with values:
+  //  - NS_ERROR_FAILURE in obvious case of error
+  //  - NS_OK in case of success to complete the code but missing process (GPU)
+  using ProcessPromise =
+      MozPromise<RefPtr<SandboxTestingParent>, nsresult, true>;
+
+ private:
+  virtual ~SandboxTest() = default;
+  nsTArray<RefPtr<SandboxTestingParent>> mSandboxTestingParents;
+  RefPtr<gmp::GMPContentParent::CloseBlocker> mGMPContentParentWrapper;
+#if defined(XP_WIN)
+  bool mChromeDirExisted = false;
+#endif
+};
+
+}  // namespace mozilla
+#endif  // mozilla_SandboxTest_h
diff --git a/security/sandbox/common/test/SandboxTestingChild.cpp b/security/sandbox/common/test/SandboxTestingChild.cpp
new file mode 100644
index 0000000000..3a9d61556c
--- /dev/null
+++ b/security/sandbox/common/test/SandboxTestingChild.cpp
@@ -0,0 +1,194 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+#include "SandboxTestingChild.h"
+#include "SandboxTestingChildTests.h"
+#include "SandboxTestingThread.h"
+#include "mozilla/ipc/Endpoint.h"
+#include "mozilla/ipc/UtilityProcessSandboxing.h"
+#include "mozilla/ipc/UtilityProcessChild.h"
+
+#ifdef XP_LINUX
+#  include "mozilla/Sandbox.h"
+#endif
+
+#include "nsXULAppAPI.h"
+
+namespace mozilla {
+
+StaticRefPtr<SandboxTestingChild> SandboxTestingChild::sInstance;
+
+bool SandboxTestingChild::IsTestThread() { return mThread->IsOnThread(); }
+
+void SandboxTestingChild::PostToTestThread(
+    already_AddRefed<nsIRunnable>&& runnable) {
+  mThread->Dispatch(std::move(runnable));
+}
+
+/* static */
+bool SandboxTestingChild::Initialize(
+    Endpoint<PSandboxTestingChild>&& aSandboxTestingEndpoint) {
+  MOZ_ASSERT(!sInstance);
+  SandboxTestingThread* thread = SandboxTestingThread::Create();
+  if (!thread) {
+    return false;
+  }
+  sInstance =
+      new SandboxTestingChild(thread, std::move(aSandboxTestingEndpoint));
+  thread->Dispatch(NewRunnableMethod<Endpoint<PSandboxTestingChild>&&>(
+      "SandboxTestingChild::Bind", sInstance.get(), &SandboxTestingChild::Bind,
+      std::move(aSandboxTestingEndpoint)));
+  return true;
+}
+
+/* static */
+SandboxTestingChild* SandboxTestingChild::GetInstance() {
+  MOZ_ASSERT(sInstance, "Must initialize SandboxTestingChild before using it");
+  return sInstance;
+}
+
+SandboxTestingChild::SandboxTestingChild(
+    SandboxTestingThread* aThread, Endpoint<PSandboxTestingChild>&& aEndpoint)
+    : mThread(aThread) {}
+
+SandboxTestingChild::~SandboxTestingChild() = default;
+
+void SandboxTestingChild::Bind(Endpoint<PSandboxTestingChild>&& aEndpoint) {
+  MOZ_RELEASE_ASSERT(mThread->IsOnThread());
+  DebugOnly<bool> ok = aEndpoint.Bind(this);
+  MOZ_ASSERT(ok);
+
+#ifdef XP_LINUX
+  bool sandboxCrashOnError = SetSandboxCrashOnError(false);
+#endif
+
+  if (XRE_IsContentProcess()) {
+    RunTestsContent(this);
+  }
+
+  if (XRE_IsRDDProcess()) {
+    RunTestsRDD(this);
+  }
+
+  if (XRE_IsGMPluginProcess()) {
+    RunTestsGMPlugin(this);
+  }
+
+  if (XRE_IsSocketProcess()) {
+    RunTestsSocket(this);
+  }
+
+  if (XRE_IsGPUProcess()) {
+    RunTestsGPU(this);
+  }
+
+  if (XRE_IsUtilityProcess()) {
+    RefPtr<ipc::UtilityProcessChild> s = ipc::UtilityProcessChild::Get();
+    MOZ_ASSERT(s, "Unable to grab a UtilityProcessChild");
+    switch (s->mSandbox) {
+      case ipc::SandboxingKind::GENERIC_UTILITY:
+        RunTestsGenericUtility(this);
+#ifdef MOZ_APPLEMEDIA
+        [[fallthrough]];
+      case ipc::SandboxingKind::UTILITY_AUDIO_DECODING_APPLE_MEDIA:
+#endif
+#ifdef XP_WIN
+        [[fallthrough]];
+      case ipc::SandboxingKind::UTILITY_AUDIO_DECODING_WMF:
+#endif
+        RunTestsUtilityAudioDecoder(this, s->mSandbox);
+        break;
+
+      default:
+        MOZ_ASSERT(false, "Invalid SandboxingKind");
+        break;
+    }
+  }
+
+#ifdef XP_LINUX
+  SetSandboxCrashOnError(sandboxCrashOnError);
+#endif
+
+  // Tell SandboxTest that this process is done with all tests.
+  SendTestCompleted();
+}
+
+void SandboxTestingChild::ActorDestroy(ActorDestroyReason aWhy) {
+  MOZ_ASSERT(mThread->IsOnThread());
+  NS_DispatchToMainThread(NS_NewRunnableFunction(
+      "SandboxChildDestroyer", []() { SandboxTestingChild::Destroy(); }));
+}
+
+void SandboxTestingChild::Destroy() {
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(sInstance);
+  sInstance = nullptr;
+}
+
+ipc::IPCResult SandboxTestingChild::RecvShutDown() {
+  Close();
+  return IPC_OK();
+}
+
+void SandboxTestingChild::ReportNoTests() {
+  SendReportTestResults("dummy_test"_ns, /* passed */ true,
+                        "The test framework fails if there are no cases."_ns);
+}
+
+template <typename F>
+void SandboxTestingChild::ErrnoTest(const nsCString& aName, bool aExpectSuccess,
+                                    F&& aFunction) {
+  int status = aFunction() >= 0 ? 0 : errno;
+  PosixTest(aName, aExpectSuccess, status);
+}
+
+template <typename F>
+void SandboxTestingChild::ErrnoValueTest(const nsCString& aName,
+                                         int aExpectedErrno, F&& aFunction) {
+  int status = aFunction() >= 0 ? 0 : errno;
+  PosixTest(aName, aExpectedErrno == 0, status, Some(aExpectedErrno));
+}
+
+void SandboxTestingChild::PosixTest(const nsCString& aName, bool aExpectSuccess,
+                                    int aStatus, Maybe<int> aExpectedError) {
+  nsAutoCString message;
+  bool passed;
+
+  // The "expected" arguments are a little redundant.
+  MOZ_ASSERT(!aExpectedError || aExpectSuccess == (*aExpectedError == 0));
+
+  // Decide whether the test passed, and stringify the actual result.
+  if (aStatus == 0) {
+    message = "Succeeded"_ns;
+    passed = aExpectSuccess;
+  } else {
+    message = "Error: "_ns;
+    message += strerror(aStatus);
+    if (aExpectedError) {
+      passed = aStatus == *aExpectedError;
+    } else {
+      passed = !aExpectSuccess;
+    }
+  }
+
+  // If something unexpected happened, mention the expected result.
+  if (!passed) {
+    message += "; expected ";
+    if (aExpectSuccess) {
+      message += "success";
+    } else {
+      message += "error";
+      if (aExpectedError) {
+        message += ": ";
+        message += strerror(*aExpectedError);
+      }
+    }
+  }
+
+  SendReportTestResults(aName, passed, message);
+}
+
+}  // namespace mozilla
diff --git a/security/sandbox/common/test/SandboxTestingChild.h b/security/sandbox/common/test/SandboxTestingChild.h
new file mode 100644
index 0000000000..45c9893a63
--- /dev/null
+++ b/security/sandbox/common/test/SandboxTestingChild.h
@@ -0,0 +1,86 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_SandboxTestingChild_h
+#define mozilla_SandboxTestingChild_h
+
+#include "mozilla/PSandboxTestingChild.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/Monitor.h"
+#include "mozilla/StaticPtr.h"
+#include "mozilla/UniquePtr.h"
+#include "nsISupports.h"
+
+#ifdef XP_UNIX
+#  include "nsString.h"
+#endif
+
+#if !defined(MOZ_SANDBOX) || !defined(MOZ_DEBUG) || !defined(ENABLE_TESTS)
+#  error "This file should not be used outside of debug with tests"
+#endif
+
+namespace mozilla {
+
+class SandboxTestingThread;
+
+/**
+ * Runs tests that check sandbox in child process, depending on process type.
+ */
+class SandboxTestingChild : public PSandboxTestingChild {
+ public:
+  static bool Initialize(
+      Endpoint<PSandboxTestingChild>&& aSandboxTestingEndpoint);
+  static SandboxTestingChild* GetInstance();
+  static void Destroy();
+
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(SandboxTestingChild, override)
+
+  bool IsTestThread();
+  void PostToTestThread(already_AddRefed<nsIRunnable>&& runnable);
+
+  void ActorDestroy(ActorDestroyReason aWhy) override;
+
+  virtual ipc::IPCResult RecvShutDown();
+
+  // Helper to return that no test have been executed. Tests should make sure
+  // they have some fallback through that otherwise the framework will consider
+  // absence of test report as a failure.
+  inline void ReportNoTests();
+
+  // For test cases that return an error number or 0, like newer POSIX
+  // APIs.  If `aExpectSuccess` is true, the test passes if the status is
+  // 0; otherwise, the test requires a specific error if `aExpectedError`
+  // is `Some(n)` or any nonzero status if it's `Nothing()`.
+  void PosixTest(const nsCString& aName, bool aExpectSuccess, int aStatus,
+                 Maybe<int> aExpectedError = Nothing());
+
+  // For test cases that return a negative number and set `errno` to
+  // indicate error, like classical Unix APIs; takes a callable, which
+  // is used only in this function call (so `[&]` captures are safe).
+  template <typename F>
+  void ErrnoTest(const nsCString& aName, bool aExpectSuccess, F&& aFunction);
+
+  // Similar to ErrnoTest, except that we want to compare a specific `errno`
+  // being returned.
+  template <typename F>
+  void ErrnoValueTest(const nsCString& aName, int aExpectedErrno,
+                      F&& aFunction);
+
+ private:
+  explicit SandboxTestingChild(SandboxTestingThread* aThread,
+                               Endpoint<PSandboxTestingChild>&& aEndpoint);
+  ~SandboxTestingChild();
+
+  void Bind(Endpoint<PSandboxTestingChild>&& aEndpoint);
+
+  UniquePtr<SandboxTestingThread> mThread;
+
+  static StaticRefPtr<SandboxTestingChild> sInstance;
+};
+
+}  // namespace mozilla
+
+#endif  // mozilla_SandboxTestingChild_h
diff --git a/security/sandbox/common/test/SandboxTestingChildTests.h b/security/sandbox/common/test/SandboxTestingChildTests.h
new file mode 100644
index 0000000000..3dd748daba
--- /dev/null
+++ b/security/sandbox/common/test/SandboxTestingChildTests.h
@@ -0,0 +1,876 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+#include "SandboxTestingChild.h"
+
+#include "mozilla/StaticPrefs_security.h"
+#include "mozilla/ipc/UtilityProcessSandboxing.h"
+#ifdef XP_MACOSX
+#  include "nsCocoaFeatures.h"
+#endif
+#include "nsXULAppAPI.h"
+
+#ifdef XP_UNIX
+#  include <fcntl.h>
+#  include <netdb.h>
+#  ifdef XP_LINUX
+#    include <linux/mempolicy.h>
+#    include <sched.h>
+#    include <sys/ioctl.h>
+#    include <sys/prctl.h>
+#    include <sys/resource.h>
+#    include <sys/socket.h>
+#    include <sys/statfs.h>
+#    include <sys/syscall.h>
+#    include <sys/sysmacros.h>
+#    include <sys/time.h>
+#    include <sys/un.h>
+#    include <sys/utsname.h>
+#    include <termios.h>
+#    include "mozilla/ProcInfo_linux.h"
+#    include "mozilla/UniquePtrExtensions.h"
+#    ifdef MOZ_X11
+#      include "X11/Xlib.h"
+#      include "X11UndefineNone.h"
+#    endif  // MOZ_X11
+#  endif    // XP_LINUX
+#  include <sys/socket.h>
+#  include <sys/stat.h>
+#  include <sys/types.h>
+#  include <time.h>
+#  include <unistd.h>
+#endif
+
+#ifdef XP_MACOSX
+#  if defined(__SSE2__) || defined(_M_X64) || \
+      (defined(_M_IX86_FP) && _M_IX86_FP >= 2)
+#    include "emmintrin.h"
+#  endif
+#  include <spawn.h>
+#  include <CoreFoundation/CoreFoundation.h>
+#  include <CoreGraphics/CoreGraphics.h>
+#  include <AudioToolbox/AudioToolbox.h>
+namespace ApplicationServices {
+#  include <ApplicationServices/ApplicationServices.h>
+}
+#endif
+
+#ifdef XP_WIN
+#  include <stdio.h>
+#  include <winternl.h>
+
+#  include "mozilla/DynamicallyLinkedFunctionPtr.h"
+#  include "nsAppDirectoryServiceDefs.h"
+#  include "mozilla/WindowsProcessMitigations.h"
+#endif
+
+#ifdef XP_LINUX
+// Defined in <linux/watch_queue.h> which was added in 5.8
+#  ifndef O_NOTIFICATION_PIPE
+#    define O_NOTIFICATION_PIPE O_EXCL
+#  endif
+#endif
+
+constexpr bool kIsDebug =
+#ifdef DEBUG
+    true;
+#else
+    false;
+#endif
+
+namespace mozilla {
+
+#ifdef XP_LINUX
+static void RunTestsSched(SandboxTestingChild* child) {
+  struct sched_param param_pid_0 = {};
+  child->ErrnoTest("sched_getparam(0)"_ns, true,
+                   [&] { return sched_getparam(0, &param_pid_0); });
+
+  struct sched_param param_pid_tid = {};
+  child->ErrnoTest("sched_getparam(tid)"_ns, true, [&] {
+    return sched_getparam((pid_t)syscall(__NR_gettid), &param_pid_tid);
+  });
+
+  struct sched_param param_pid_Ntid = {};
+  child->ErrnoValueTest("sched_getparam(Ntid)"_ns, EPERM, [&] {
+    return sched_getparam((pid_t)(syscall(__NR_gettid) - 1), &param_pid_Ntid);
+  });
+}
+#endif
+
+// Tests that apply to every process type (more or less)
+static void RunGenericTests(SandboxTestingChild* child, bool aIsGMP = false) {
+#ifdef XP_LINUX
+  // Check ABI issues with 32-bit arguments on 64-bit platforms.
+  if (sizeof(void*) == 8) {
+    static constexpr uint64_t kHighBits = 0xDEADBEEF00000000;
+
+    struct timespec ts0, ts1;
+    child->ErrnoTest("high_bits_gettime"_ns, true, [&] {
+      return syscall(__NR_clock_gettime, kHighBits | CLOCK_MONOTONIC, &ts0);
+    });
+    // Try to make sure we got the correct clock by reading it again and
+    // comparing to see if the times are vaguely similar.
+    int rv = clock_gettime(CLOCK_MONOTONIC, &ts1);
+    MOZ_RELEASE_ASSERT(rv == 0);
+    MOZ_RELEASE_ASSERT(ts0.tv_sec <= ts1.tv_sec + 1);
+    MOZ_RELEASE_ASSERT(ts1.tv_sec <= ts0.tv_sec + 60);
+
+    // Check some non-zeroth arguments.  (fcntl is convenient for
+    // this, but GMP has a stricter policy, so skip it there.)
+    if (!aIsGMP) {
+      int flags;
+      child->ErrnoTest("high_bits_fcntl_getfl"_ns, true, [&] {
+        flags = syscall(__NR_fcntl, 0, kHighBits | F_GETFL);
+        return flags;
+      });
+      MOZ_RELEASE_ASSERT(flags == fcntl(0, F_GETFL));
+
+      int fds[2];
+      rv = pipe(fds);
+      MOZ_RELEASE_ASSERT(rv >= 0);
+      child->ErrnoTest("high_bits_fcntl_setfl"_ns, true, [&] {
+        return syscall(__NR_fcntl, fds[0], kHighBits | F_SETFL,
+                       kHighBits | O_NONBLOCK);
+      });
+      flags = fcntl(fds[0], F_GETFL);
+      MOZ_RELEASE_ASSERT(flags >= 0);
+      MOZ_RELEASE_ASSERT(flags & O_NONBLOCK);
+    }
+  }
+#endif  // XP_LINUX
+}
+
+#ifdef XP_WIN
+/**
+ * Uses NtCreateFile directly to test file system brokering.
+ *
+ */
+static void FileTest(const nsCString& aName, const char* aSpecialDirName,
+                     const nsString& aRelativeFilePath, ACCESS_MASK aAccess,
+                     bool aExpectSuccess, SandboxTestingChild* aChild) {
+  static const StaticDynamicallyLinkedFunctionPtr<decltype(&NtCreateFile)>
+      pNtCreateFile(L"ntdll.dll", "NtCreateFile");
+  static const StaticDynamicallyLinkedFunctionPtr<decltype(&NtClose)> pNtClose(
+      L"ntdll.dll", "NtClose");
+
+  // Start the filename with the NT namespace
+  nsString testFilename(u"\\??\\"_ns);
+  nsString dirPath;
+  aChild->SendGetSpecialDirectory(nsDependentCString(aSpecialDirName),
+                                  &dirPath);
+  testFilename.Append(dirPath);
+  testFilename.AppendLiteral("\\");
+  testFilename.Append(aRelativeFilePath);
+
+  UNICODE_STRING uniFileName;
+  ::RtlInitUnicodeString(&uniFileName, testFilename.get());
+
+  OBJECT_ATTRIBUTES objectAttributes;
+  InitializeObjectAttributes(&objectAttributes, &uniFileName,
+                             OBJ_CASE_INSENSITIVE, nullptr, nullptr);
+
+  HANDLE fileHandle = INVALID_HANDLE_VALUE;
+  IO_STATUS_BLOCK ioStatusBlock = {};
+
+  ULONG createOptions = StringEndsWith(testFilename, u"\\"_ns) ||
+                                StringEndsWith(testFilename, u"/"_ns)
+                            ? FILE_DIRECTORY_FILE
+                            : FILE_NON_DIRECTORY_FILE;
+  NTSTATUS status = pNtCreateFile(
+      &fileHandle, aAccess, &objectAttributes, &ioStatusBlock, nullptr, 0, 0,
+      FILE_OPEN_IF, createOptions | FILE_SYNCHRONOUS_IO_NONALERT, nullptr, 0);
+
+  if (fileHandle != INVALID_HANDLE_VALUE) {
+    pNtClose(fileHandle);
+  }
+
+  nsCString accessString;
+  if ((aAccess & FILE_GENERIC_READ) == FILE_GENERIC_READ) {
+    accessString.AppendLiteral("r");
+  }
+  if ((aAccess & FILE_GENERIC_WRITE) == FILE_GENERIC_WRITE) {
+    accessString.AppendLiteral("w");
+  }
+  if ((aAccess & FILE_GENERIC_EXECUTE) == FILE_GENERIC_EXECUTE) {
+    accessString.AppendLiteral("e");
+  }
+
+  nsCString msgRelPath = NS_ConvertUTF16toUTF8(aRelativeFilePath);
+  for (size_t i = 0, j = 0; i < aRelativeFilePath.Length(); ++i, ++j) {
+    if (aRelativeFilePath[i] == u'\\') {
+      msgRelPath.Insert('\\', j++);
+    }
+  }
+
+  nsCString message;
+  message.AppendPrintf(
+      "Special dir: %s, file: %s, access: %s , returned status: %lx",
+      aSpecialDirName, msgRelPath.get(), accessString.get(), status);
+
+  aChild->SendReportTestResults(aName, aExpectSuccess == NT_SUCCESS(status),
+                                message);
+}
+#endif
+
+#ifdef XP_MACOSX
+/*
+ * Test if this process can launch another process with posix_spawnp,
+ * exec, and LSOpenCFURLRef. All launches are expected to fail. In processes
+ * where the sandbox permits reading of file metadata (content processes at
+ * this time), we expect the posix_spawnp error to be EPERM. In processes
+ * without that permission, we expect ENOENT. Changing the sandbox policy
+ * may break this assumption, but the important aspect to test for is that the
+ * launch is not permitted.
+ */
+void RunMacTestLaunchProcess(SandboxTestingChild* child,
+                             int aPosixSpawnExpectedError = ENOENT) {
+  // Test that posix_spawnp fails
+  char* argv[2];
+  argv[0] = const_cast<char*>("bash");
+  argv[1] = NULL;
+  int rv = posix_spawnp(NULL, "/bin/bash", NULL, NULL, argv, NULL);
+  nsPrintfCString posixSpawnMessage("posix_spawnp returned %d, expected %d", rv,
+                                    aPosixSpawnExpectedError);
+  child->SendReportTestResults("posix_spawnp test"_ns,
+                               rv == aPosixSpawnExpectedError,
+                               posixSpawnMessage);
+
+  // Test that exec fails
+  child->ErrnoTest("execv /bin/bash test"_ns, false, [&] {
+    char* argvp = NULL;
+    return execv("/bin/bash", &argvp);
+  });
+
+  // Test that launching an application using LSOpenCFURLRef fails
+  char* uri;
+  if (nsCocoaFeatures::OnCatalinaOrLater()) {
+    uri = const_cast<char*>("/System/Applications/Utilities/Console.app");
+  } else {
+    uri = const_cast<char*>("/Applications/Utilities/Console.app");
+  }
+  CFStringRef filePath = ::CFStringCreateWithCString(kCFAllocatorDefault, uri,
+                                                     kCFStringEncodingUTF8);
+  CFURLRef urlRef = ::CFURLCreateWithFileSystemPath(
+      kCFAllocatorDefault, filePath, kCFURLPOSIXPathStyle, false);
+  if (!urlRef) {
+    child->SendReportTestResults("LSOpenCFURLRef"_ns, false,
+                                 "CFURLCreateWithFileSystemPath failed"_ns);
+    return;
+  }
+
+  OSStatus status = ApplicationServices::LSOpenCFURLRef(urlRef, NULL);
+  ::CFRelease(urlRef);
+  nsPrintfCString lsMessage(
+      "LSOpenCFURLRef returned %d, "
+      "expected kLSServerCommunicationErr (%d)",
+      status, ApplicationServices::kLSServerCommunicationErr);
+  child->SendReportTestResults(
+      "LSOpenCFURLRef"_ns,
+      status == ApplicationServices::kLSServerCommunicationErr, lsMessage);
+}
+
+/*
+ * Test if this process can connect to the macOS window server.
+ * When |aShouldHaveAccess| is true, the test passes if access is __permitted__.
+ * When |aShouldHaveAccess| is false, the test passes if access is __blocked__.
+ */
+void RunMacTestWindowServer(SandboxTestingChild* child,
+                            bool aShouldHaveAccess = false) {
+  // CGSessionCopyCurrentDictionary() returns NULL when a
+  // connection to the window server is not available.
+  CFDictionaryRef windowServerDict = CGSessionCopyCurrentDictionary();
+  bool gotWindowServerDetails = (windowServerDict != nullptr);
+  bool testPassed = (gotWindowServerDetails == aShouldHaveAccess);
+  child->SendReportTestResults(
+      "CGSessionCopyCurrentDictionary"_ns, testPassed,
+      gotWindowServerDetails
+          ? "dictionary returned, access is permitted"_ns
+          : "no dictionary returned, access appears blocked"_ns);
+  if (windowServerDict != nullptr) {
+    CFRelease(windowServerDict);
+  }
+}
+
+/*
+ * Test if this process can get access to audio components on macOS.
+ * When |aShouldHaveAccess| is true, the test passes if access is __permitted__.
+ * When |aShouldHaveAccess| is false, the test passes if access is __blocked__.
+ */
+void RunMacTestAudioAPI(SandboxTestingChild* child,
+                        bool aShouldHaveAccess = false) {
+  AudioStreamBasicDescription inputFormat;
+  inputFormat.mFormatID = kAudioFormatMPEG4AAC;
+  inputFormat.mSampleRate = 48000.0;
+  inputFormat.mChannelsPerFrame = 2;
+  inputFormat.mBitsPerChannel = 0;
+  inputFormat.mFormatFlags = 0;
+  inputFormat.mFramesPerPacket = 1024;
+  inputFormat.mBytesPerPacket = 0;
+
+  UInt32 inputFormatSize = sizeof(inputFormat);
+  OSStatus status = AudioFormatGetProperty(
+      kAudioFormatProperty_FormatInfo, 0, NULL, &inputFormatSize, &inputFormat);
+
+  bool gotAudioFormat = (status == 0);
+  bool testPassed = (gotAudioFormat == aShouldHaveAccess);
+  child->SendReportTestResults(
+      "AudioFormatGetProperty"_ns, testPassed,
+      gotAudioFormat ? "got audio format, access is permitted"_ns
+                     : "no audio format, access appears blocked"_ns);
+}
+#endif /* XP_MACOSX */
+
+#ifdef XP_WIN
+void RunWinTestWin32k(SandboxTestingChild* child,
+                      bool aShouldHaveAccess = true) {
+  bool isLockedDown = (IsWin32kLockedDown() == true);
+  bool testPassed = (isLockedDown == aShouldHaveAccess);
+  child->SendReportTestResults(
+      "Win32kLockdown"_ns, testPassed,
+      isLockedDown ? "got lockdown, access is blocked"_ns
+                   : "no lockdown, access appears permitted"_ns);
+}
+#endif  // XP_WIN
+
+void RunTestsContent(SandboxTestingChild* child) {
+  MOZ_ASSERT(child, "No SandboxTestingChild*?");
+
+  RunGenericTests(child);
+
+#ifdef XP_UNIX
+  struct stat st;
+  static const char kAllowedPath[] = "/usr/lib";
+
+  child->ErrnoTest("fstatat_as_stat"_ns, true,
+                   [&] { return fstatat(AT_FDCWD, kAllowedPath, &st, 0); });
+  child->ErrnoTest("fstatat_as_lstat"_ns, true, [&] {
+    return fstatat(AT_FDCWD, kAllowedPath, &st, AT_SYMLINK_NOFOLLOW);
+  });
+
+#  ifdef XP_LINUX
+  child->ErrnoTest("fstatat_as_fstat"_ns, true,
+                   [&] { return fstatat(0, "", &st, AT_EMPTY_PATH); });
+
+  const struct timespec usec = {0, 1000};
+  child->ErrnoTest("nanosleep"_ns, true,
+                   [&] { return nanosleep(&usec, nullptr); });
+
+  struct timespec res = {0, 0};
+  child->ErrnoTest("clock_getres"_ns, true,
+                   [&] { return clock_getres(CLOCK_REALTIME, &res); });
+
+  // same process is allowed
+  struct timespec tproc = {0, 0};
+  clockid_t same_process = MAKE_PROCESS_CPUCLOCK(getpid(), CPUCLOCK_SCHED);
+  child->ErrnoTest("clock_gettime_same_process"_ns, true,
+                   [&] { return clock_gettime(same_process, &tproc); });
+
+  // different process is blocked by sandbox (SIGSYS, kernel would return
+  // EINVAL)
+  struct timespec tprocd = {0, 0};
+  clockid_t diff_process = MAKE_PROCESS_CPUCLOCK(1, CPUCLOCK_SCHED);
+  child->ErrnoValueTest("clock_gettime_diff_process"_ns, ENOSYS,
+                        [&] { return clock_gettime(diff_process, &tprocd); });
+
+  // thread is allowed
+  struct timespec tthread = {0, 0};
+  clockid_t thread =
+      MAKE_THREAD_CPUCLOCK((pid_t)syscall(__NR_gettid), CPUCLOCK_SCHED);
+  child->ErrnoTest("clock_gettime_thread"_ns, true,
+                   [&] { return clock_gettime(thread, &tthread); });
+
+  // getcpu is allowed
+  // We're using syscall directly because:
+  // - sched_getcpu uses vdso and as a result doesn't go through the sandbox.
+  // - getcpu isn't defined in the header files we're using yet.
+  int c;
+  child->ErrnoTest("getcpu"_ns, true,
+                   [&] { return syscall(SYS_getcpu, &c, NULL, NULL); });
+
+  // An abstract socket that does not starts with '/', so we don't want it to
+  // work.
+  // Checking ENETUNREACH should be thrown by SandboxBrokerClient::Connect()
+  // when it detects it does not starts with a '/'
+  child->ErrnoValueTest("connect_abstract_blocked"_ns, ENETUNREACH, [&] {
+    int sockfd;
+    struct sockaddr_un addr;
+    char str[] = "\0xyz";  // Abstract socket requires first byte to be NULL
+    size_t str_size = 4;
+
+    memset(&addr, 0, sizeof(struct sockaddr_un));
+    addr.sun_family = AF_UNIX;
+    memcpy(&addr.sun_path, str, str_size);
+
+    sockfd = socket(AF_UNIX, SOCK_STREAM, 0);
+    if (sockfd == -1) {
+      return -1;
+    }
+
+    int con_st = connect(sockfd, (struct sockaddr*)&addr,
+                         sizeof(sa_family_t) + str_size);
+    return con_st;
+  });
+
+  // An abstract socket that does starts with /, so we do want it to work.
+  // Checking ECONNREFUSED because this is what the broker should get
+  // when trying to establish the connect call for us if it's allowed;
+  // otherwise we get EACCES, meaning that it was passed to the broker
+  // (unlike the previous test) but rejected.
+  const int errorForX =
+      StaticPrefs::security_sandbox_content_headless_AtStartup() ? EACCES
+                                                                 : ECONNREFUSED;
+  child->ErrnoValueTest("connect_abstract_permit"_ns, errorForX, [&] {
+    int sockfd;
+    struct sockaddr_un addr;
+    // we re-use actual X path, because this is what is allowed within
+    // SandboxBrokerPolicyFactory::InitContentPolicy()
+    // We can't just use any random path allowed, but one with CONNECT allowed.
+
+    // (Note that the real X11 sockets have names like `X0` for
+    // display `:0`; there shouldn't be anything named just `X`.)
+
+    // Abstract socket requires first byte to be NULL
+    char str[] = "\0/tmp/.X11-unix/X";
+    size_t str_size = 17;
+
+    memset(&addr, 0, sizeof(struct sockaddr_un));
+    addr.sun_family = AF_UNIX;
+    memcpy(&addr.sun_path, str, str_size);
+
+    sockfd = socket(AF_UNIX, SOCK_STREAM, 0);
+    if (sockfd == -1) {
+      return -1;
+    }
+
+    int con_st = connect(sockfd, (struct sockaddr*)&addr,
+                         sizeof(sa_family_t) + str_size);
+    return con_st;
+  });
+
+  // Testing FIPS-relevant files, which need to be accessible
+  std::vector<std::pair<const char*, bool>> open_tests = {
+      {"/dev/random", true}};
+  // Not all systems have that file, so we only test access, if it exists
+  // in the first place
+  if (stat("/proc/sys/crypto/fips_enabled", &st) == 0) {
+    open_tests.push_back({"/proc/sys/crypto/fips_enabled", true});
+  }
+
+  for (const std::pair<const char*, bool>& to_open : open_tests) {
+    child->ErrnoTest("open("_ns + nsCString(to_open.first) + ")"_ns,
+                     to_open.second, [&] {
+                       int fd = open(to_open.first, O_RDONLY);
+                       if (to_open.second && fd > 0) {
+                         close(fd);
+                       }
+                       return fd;
+                     });
+  }
+
+  child->ErrnoTest("statfs"_ns, true, [] {
+    struct statfs sf;
+    return statfs("/usr/share", &sf);
+  });
+
+  child->ErrnoTest("pipe2"_ns, true, [] {
+    int fds[2];
+    int rv = pipe2(fds, O_CLOEXEC);
+    int savedErrno = errno;
+    if (rv == 0) {
+      close(fds[0]);
+      close(fds[1]);
+    }
+    errno = savedErrno;
+    return rv;
+  });
+
+  child->ErrnoValueTest("chroot"_ns, ENOSYS, [] { return chroot("/"); });
+
+  child->ErrnoValueTest("pipe2_notif"_ns, ENOSYS, [] {
+    int fds[2];
+    return pipe2(fds, O_NOTIFICATION_PIPE);
+  });
+
+#    ifdef MOZ_X11
+  // Check that X11 access is blocked (bug 1129492).
+  // This will fail if security.sandbox.content.headless is turned off.
+  if (PR_GetEnv("DISPLAY")) {
+    Display* disp = XOpenDisplay(nullptr);
+
+    child->SendReportTestResults(
+        "x11_access"_ns, !disp,
+        disp ? "XOpenDisplay succeeded"_ns : "XOpenDisplay failed"_ns);
+    if (disp) {
+      XCloseDisplay(disp);
+    }
+  }
+#    endif  // MOZ_X11
+
+  child->ErrnoTest("realpath localtime"_ns, true, [] {
+    char buf[PATH_MAX];
+    return realpath("/etc/localtime", buf) ? 0 : -1;
+  });
+
+#  endif  // XP_LINUX
+
+#  ifdef XP_MACOSX
+  RunMacTestLaunchProcess(child, EPERM);
+  RunMacTestWindowServer(child);
+  RunMacTestAudioAPI(child, true);
+#  endif
+
+#elif XP_WIN
+  FileTest("read from chrome"_ns, NS_APP_USER_CHROME_DIR, u"sandboxTest.txt"_ns,
+           FILE_GENERIC_READ, true, child);
+  FileTest("read from profile via relative path"_ns, NS_APP_USER_CHROME_DIR,
+           u"..\\sandboxTest.txt"_ns, FILE_GENERIC_READ, false, child);
+  // The profile dir is the parent of the chrome dir.
+  FileTest("read from chrome using forward slash"_ns,
+           NS_APP_USER_PROFILE_50_DIR, u"chrome/sandboxTest.txt"_ns,
+           FILE_GENERIC_READ, false, child);
+
+  // Note: these only pass in DEBUG builds because we allow write access to the
+  // temp dir for certain test logs and that is where the profile is created.
+  FileTest("read from profile"_ns, NS_APP_USER_PROFILE_50_DIR,
+           u"sandboxTest.txt"_ns, FILE_GENERIC_READ, kIsDebug, child);
+  FileTest("read/write from chrome"_ns, NS_APP_USER_CHROME_DIR,
+           u"sandboxTest.txt"_ns, FILE_GENERIC_READ | FILE_GENERIC_WRITE,
+           kIsDebug, child);
+#else
+    child->ReportNoTests();
+#endif
+}
+
+void RunTestsSocket(SandboxTestingChild* child) {
+  MOZ_ASSERT(child, "No SandboxTestingChild*?");
+
+  RunGenericTests(child);
+
+#ifdef XP_UNIX
+  child->ErrnoTest("getaddrinfo"_ns, true, [&] {
+    struct addrinfo* res;
+    int rv = getaddrinfo("localhost", nullptr, nullptr, &res);
+    if (res != nullptr) {
+      freeaddrinfo(res);
+    }
+    return rv;
+  });
+
+#  ifdef XP_LINUX
+  child->ErrnoTest("prctl_allowed"_ns, true, [&] {
+    int rv = prctl(PR_SET_DUMPABLE, 0, 0, 0, 0);
+    return rv;
+  });
+
+  child->ErrnoTest("prctl_blocked"_ns, false, [&] {
+    int rv = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
+    return rv;
+  });
+
+  // Testing FIPS-relevant files, which need to be accessible
+  std::vector<std::pair<const char*, bool>> open_tests = {
+      {"/dev/random", true}};
+  // Not all systems have that file, so we only test access, if it exists
+  // in the first place
+  struct stat st;
+  if (stat("/proc/sys/crypto/fips_enabled", &st) == 0) {
+    open_tests.push_back({"/proc/sys/crypto/fips_enabled", true});
+  }
+
+  for (const std::pair<const char*, bool>& to_open : open_tests) {
+    child->ErrnoTest("open("_ns + nsCString(to_open.first) + ")"_ns,
+                     to_open.second, [&] {
+                       int fd = open(to_open.first, O_RDONLY);
+                       if (to_open.second && fd > 0) {
+                         close(fd);
+                       }
+                       return fd;
+                     });
+  }
+
+  // getcpu is allowed
+  // We're using syscall directly because:
+  // - sched_getcpu uses vdso and as a result doesn't go through the sandbox.
+  // - getcpu isn't defined in the header files we're using yet.
+  int c;
+  child->ErrnoTest("getcpu"_ns, true,
+                   [&] { return syscall(SYS_getcpu, &c, NULL, NULL); });
+#  endif  // XP_LINUX
+#elif XP_MACOSX
+  RunMacTestLaunchProcess(child);
+  RunMacTestWindowServer(child);
+  RunMacTestAudioAPI(child);
+#else   // XP_UNIX
+    child->ReportNoTests();
+#endif  // XP_UNIX
+}
+
+void RunTestsRDD(SandboxTestingChild* child) {
+  MOZ_ASSERT(child, "No SandboxTestingChild*?");
+
+  RunGenericTests(child);
+
+#ifdef XP_UNIX
+#  ifdef XP_LINUX
+  child->ErrnoValueTest("ioctl_tiocsti"_ns, ENOSYS, [&] {
+    int rv = ioctl(1, TIOCSTI, "x");
+    return rv;
+  });
+
+  struct rusage res = {};
+  child->ErrnoTest("getrusage"_ns, true, [&] {
+    int rv = getrusage(RUSAGE_SELF, &res);
+    return rv;
+  });
+
+  child->ErrnoValueTest("unlink"_ns, ENOENT, [&] {
+    int rv = unlink("");
+    return rv;
+  });
+
+  child->ErrnoValueTest("unlinkat"_ns, ENOENT, [&] {
+    int rv = unlinkat(AT_FDCWD, "", 0);
+    return rv;
+  });
+
+  RunTestsSched(child);
+
+  child->ErrnoTest("socket_inet"_ns, false,
+                   [] { return socket(AF_INET, SOCK_STREAM, 0); });
+
+  child->ErrnoTest("socket_unix"_ns, false,
+                   [] { return socket(AF_UNIX, SOCK_STREAM, 0); });
+
+  child->ErrnoTest("uname"_ns, true, [] {
+    struct utsname uts;
+    return uname(&uts);
+  });
+
+  child->ErrnoValueTest("ioctl_dma_buf"_ns, ENOTTY, [] {
+    // Apply the ioctl to the wrong kind of fd; it should fail with
+    // ENOTTY (rather than ENOSYS if it were blocked).
+    return ioctl(0, _IOW('b', 0, uint64_t), nullptr);
+  });
+
+  // getcpu is allowed
+  // We're using syscall directly because:
+  // - sched_getcpu uses vdso and as a result doesn't go through the sandbox.
+  // - getcpu isn't defined in the header files we're using yet.
+  int c;
+  child->ErrnoTest("getcpu"_ns, true,
+                   [&] { return syscall(SYS_getcpu, &c, NULL, NULL); });
+
+  // The nvidia proprietary drivers will, in some cases, try to
+  // mknod their device files; we reject this politely.
+  child->ErrnoValueTest("mknod"_ns, EPERM, [] {
+    return mknod("/dev/null", S_IFCHR | 0666, makedev(1, 3));
+  });
+
+  // nvidia defines some ioctls with the type 0x46 ('F', otherwise
+  // used by fbdev) and numbers starting from 200 (0xc8).
+  child->ErrnoValueTest("ioctl_nvidia"_ns, ENOTTY,
+                        [] { return ioctl(0, 0x46c8, nullptr); });
+
+  child->ErrnoTest("statfs"_ns, true, [] {
+    struct statfs sf;
+    return statfs("/usr/share", &sf);
+  });
+
+#  elif XP_MACOSX
+  RunMacTestLaunchProcess(child);
+  RunMacTestWindowServer(child);
+  RunMacTestAudioAPI(child, true);
+#  endif
+#else  // XP_UNIX
+#  ifdef XP_WIN
+  RunWinTestWin32k(child, false);
+#  endif  // XP_WIN
+  child->ReportNoTests();
+#endif
+}
+
+void RunTestsGMPlugin(SandboxTestingChild* child) {
+  MOZ_ASSERT(child, "No SandboxTestingChild*?");
+
+  RunGenericTests(child, /* aIsGMP = */ true);
+
+#ifdef XP_UNIX
+#  ifdef XP_LINUX
+  struct utsname utsname_res = {};
+  child->ErrnoTest("uname_restricted"_ns, true, [&] {
+    int rv = uname(&utsname_res);
+
+    nsCString expectedSysname("Linux"_ns);
+    nsCString sysname(utsname_res.sysname);
+    nsCString expectedVersion("3"_ns);
+    nsCString version(utsname_res.version);
+    if ((sysname != expectedSysname) || (version != expectedVersion)) {
+      return -1;
+    }
+
+    return rv;
+  });
+
+  child->ErrnoTest("getuid"_ns, true, [&] { return getuid(); });
+  child->ErrnoTest("getgid"_ns, true, [&] { return getgid(); });
+  child->ErrnoTest("geteuid"_ns, true, [&] { return geteuid(); });
+  child->ErrnoTest("getegid"_ns, true, [&] { return getegid(); });
+
+  RunTestsSched(child);
+
+  std::vector<std::pair<const char*, bool>> open_tests = {
+      {"/etc/ld.so.cache", true},
+      {"/proc/cpuinfo", true},
+      {"/etc/hostname", false}};
+
+  for (const std::pair<const char*, bool>& to_open : open_tests) {
+    child->ErrnoTest("open("_ns + nsCString(to_open.first) + ")"_ns,
+                     to_open.second, [&] {
+                       int fd = open(to_open.first, O_RDONLY);
+                       if (to_open.second && fd > 0) {
+                         close(fd);
+                       }
+                       return fd;
+                     });
+  }
+
+  child->ErrnoValueTest("readlink_exe"_ns, EINVAL, [] {
+    char pathBuf[PATH_MAX];
+    return readlink("/proc/self/exe", pathBuf, sizeof(pathBuf));
+  });
+
+  child->ErrnoTest("memfd_sizing"_ns, true, [] {
+    int fd = syscall(__NR_memfd_create, "sandbox-test", 0);
+    if (fd < 0) {
+      if (errno == ENOSYS) {
+        // Don't fail the test if the kernel is old.
+        return 0;
+      }
+      return -1;
+    }
+
+    int rv = ftruncate(fd, 4096);
+    int savedErrno = errno;
+    close(fd);
+    errno = savedErrno;
+    return rv;
+  });
+
+#  elif XP_MACOSX  // XP_LINUX
+  RunMacTestLaunchProcess(child);
+  /* The Mac GMP process requires access to the window server */
+  RunMacTestWindowServer(child, true /* aShouldHaveAccess */);
+  RunMacTestAudioAPI(child);
+#  endif           // XP_MACOSX
+#else              // XP_UNIX
+  child->ReportNoTests();
+#endif
+}
+
+void RunTestsGenericUtility(SandboxTestingChild* child) {
+  MOZ_ASSERT(child, "No SandboxTestingChild*?");
+
+  RunGenericTests(child);
+
+#ifdef XP_UNIX
+#  ifdef XP_LINUX
+  child->ErrnoValueTest("ioctl_tiocsti"_ns, ENOSYS, [&] {
+    int rv = ioctl(1, TIOCSTI, "x");
+    return rv;
+  });
+
+  struct rusage res;
+  child->ErrnoTest("getrusage"_ns, true, [&] {
+    int rv = getrusage(RUSAGE_SELF, &res);
+    return rv;
+  });
+#  elif XP_MACOSX  // XP_LINUX
+  RunMacTestLaunchProcess(child);
+  RunMacTestWindowServer(child);
+  RunMacTestAudioAPI(child);
+#  endif           // XP_MACOSX
+#elif XP_WIN       // XP_UNIX
+  child->ErrnoValueTest("write_only"_ns, EACCES, [&] {
+    FILE* rv = fopen("test_sandbox.txt", "w");
+    if (rv != nullptr) {
+      fclose(rv);
+      return 0;
+    }
+    return -1;
+  });
+  RunWinTestWin32k(child);
+#else              // XP_UNIX
+    child->ReportNoTests();
+#endif             // XP_MACOSX
+}
+
+void RunTestsUtilityAudioDecoder(SandboxTestingChild* child,
+                                 ipc::SandboxingKind aSandbox) {
+  MOZ_ASSERT(child, "No SandboxTestingChild*?");
+
+  RunGenericTests(child);
+
+#ifdef XP_UNIX
+#  ifdef XP_LINUX
+  // getrusage is allowed in Generic Utility and on AudioDecoder
+  struct rusage res;
+  child->ErrnoTest("getrusage"_ns, true, [&] {
+    int rv = getrusage(RUSAGE_SELF, &res);
+    return rv;
+  });
+
+  // get_mempolicy is not allowed in Generic Utility but is on AudioDecoder
+  child->ErrnoTest("get_mempolicy"_ns, true, [&] {
+    int numa_node;
+    int test_val = 0;
+    // <numaif.h> not installed by default, let's call directly the syscall
+    long rv = syscall(SYS_get_mempolicy, &numa_node, NULL, 0, (void*)&test_val,
+                      MPOL_F_NODE | MPOL_F_ADDR);
+    return rv;
+  });
+  // set_mempolicy is not allowed in Generic Utility but is on AudioDecoder
+  child->ErrnoValueTest("set_mempolicy"_ns, ENOSYS, [&] {
+    // <numaif.h> not installed by default, let's call directly the syscall
+    long rv = syscall(SYS_set_mempolicy, 0, NULL, 0);
+    return rv;
+  });
+#  elif XP_MACOSX  // XP_LINUX
+  RunMacTestLaunchProcess(child);
+  RunMacTestWindowServer(child);
+  RunMacTestAudioAPI(
+      child,
+      aSandbox == ipc::SandboxingKind::UTILITY_AUDIO_DECODING_APPLE_MEDIA);
+#  endif           // XP_MACOSX
+#else              // XP_UNIX
+#  ifdef XP_WIN
+  RunWinTestWin32k(child);
+#  endif  // XP_WIN
+  child->ReportNoTests();
+#endif    // XP_UNIX
+}
+
+void RunTestsGPU(SandboxTestingChild* child) {
+  MOZ_ASSERT(child, "No SandboxTestingChild*?");
+
+  RunGenericTests(child);
+
+#if defined(XP_WIN)
+
+  FileTest("R/W access to shader-cache dir"_ns, NS_APP_USER_PROFILE_50_DIR,
+           u"shader-cache\\"_ns, FILE_GENERIC_READ | FILE_GENERIC_WRITE, true,
+           child);
+
+  FileTest("R/W access to shader-cache files"_ns, NS_APP_USER_PROFILE_50_DIR,
+           u"shader-cache\\sandboxTest.txt"_ns,
+           FILE_GENERIC_READ | FILE_GENERIC_WRITE, true, child);
+
+#else   // defined(XP_WIN)
+  child->ReportNoTests();
+#endif  // defined(XP_WIN)
+}
+
+}  // namespace mozilla
diff --git a/security/sandbox/common/test/SandboxTestingParent.cpp b/security/sandbox/common/test/SandboxTestingParent.cpp
new file mode 100644
index 0000000000..dff2d03896
--- /dev/null
+++ b/security/sandbox/common/test/SandboxTestingParent.cpp
@@ -0,0 +1,125 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+#include "SandboxTestingParent.h"
+#include "SandboxTestingThread.h"
+#include "nsIObserverService.h"
+#include "mozilla/ipc/Endpoint.h"
+#include "mozilla/Services.h"
+#include "mozilla/SyncRunnable.h"
+#include "nsDirectoryServiceUtils.h"
+
+namespace mozilla {
+
+/* static */
+already_AddRefed<SandboxTestingParent> SandboxTestingParent::Create(
+    Endpoint<PSandboxTestingParent>&& aParentEnd) {
+  SandboxTestingThread* thread = SandboxTestingThread::Create();
+  if (!thread) {
+    return nullptr;
+  }
+  RefPtr<SandboxTestingParent> instance = new SandboxTestingParent(thread);
+  thread->Dispatch(NewRunnableMethod<Endpoint<PSandboxTestingParent>&&>(
+      "SandboxTestingParent::Bind", instance, &SandboxTestingParent::Bind,
+      std::move(aParentEnd)));
+  return instance.forget();
+}
+
+SandboxTestingParent::SandboxTestingParent(SandboxTestingThread* aThread)
+    : mThread(aThread),
+      mMonitor("SandboxTestingParent Lock"),
+      mShutdownDone(false) {}
+
+SandboxTestingParent::~SandboxTestingParent() = default;
+
+void SandboxTestingParent::Bind(Endpoint<PSandboxTestingParent>&& aEnd) {
+  MOZ_RELEASE_ASSERT(mThread->IsOnThread());
+  DebugOnly<bool> ok = aEnd.Bind(this);
+  MOZ_ASSERT(ok);
+}
+
+void SandboxTestingParent::ShutdownSandboxTestThread() {
+  MOZ_ASSERT(mThread->IsOnThread());
+  Close();
+  // Notify waiting thread that we are done.
+  MonitorAutoLock lock(mMonitor);
+  mShutdownDone = true;
+  mMonitor.Notify();
+}
+
+void SandboxTestingParent::Destroy(
+    already_AddRefed<SandboxTestingParent> aInstance) {
+  MOZ_ASSERT(NS_IsMainThread());
+  RefPtr<SandboxTestingParent> instance(aInstance);
+  if (!instance) {
+    return;
+  }
+
+  {
+    // Hold the lock while we destroy the actor on the test thread.
+    MonitorAutoLock lock(instance->mMonitor);
+    instance->mThread->Dispatch(NewRunnableMethod(
+        "SandboxTestingParent::ShutdownSandboxTestThread", instance,
+        &SandboxTestingParent::ShutdownSandboxTestThread));
+
+    // Wait for test thread to complete destruction.
+    while (!instance->mShutdownDone) {
+      instance->mMonitor.Wait();
+    }
+  }
+}
+
+void SandboxTestingParent::ActorDestroy(ActorDestroyReason aWhy) {
+  MOZ_RELEASE_ASSERT(mThread->IsOnThread());
+}
+
+mozilla::ipc::IPCResult SandboxTestingParent::RecvReportTestResults(
+    const nsCString& testName, bool passed, const nsCString& resultMessage) {
+  NS_DispatchToMainThread(
+      NS_NewRunnableFunction("SandboxReportTestResults", [=]() {
+        nsCOMPtr<nsIObserverService> observerService =
+            mozilla::services::GetObserverService();
+        MOZ_RELEASE_ASSERT(observerService);
+        nsCString passedStr(passed ? "true"_ns : "false"_ns);
+        nsString json;
+        json += u"{ \"testid\" : \""_ns + NS_ConvertUTF8toUTF16(testName) +
+                u"\", \"passed\" : "_ns + NS_ConvertUTF8toUTF16(passedStr) +
+                u", \"message\" : \""_ns +
+                NS_ConvertUTF8toUTF16(resultMessage) + u"\" }"_ns;
+        observerService->NotifyObservers(nullptr, "sandbox-test-result",
+                                         json.BeginReading());
+      }));
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult SandboxTestingParent::RecvTestCompleted() {
+  Unused << SendShutDown();
+  NS_DispatchToMainThread(
+      NS_NewRunnableFunction("SandboxReportTestResults", []() {
+        nsCOMPtr<nsIObserverService> observerService =
+            mozilla::services::GetObserverService();
+        MOZ_RELEASE_ASSERT(observerService);
+        observerService->NotifyObservers(nullptr, "sandbox-test-done", 0);
+      }));
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult SandboxTestingParent::RecvGetSpecialDirectory(
+    const nsCString& aSpecialDirName, nsString* aDirPath) {
+  RefPtr<Runnable> runnable = NS_NewRunnableFunction(
+      "SandboxTestingParent::RecvGetSpecialDirectory", [&]() {
+        nsCOMPtr<nsIFile> dir;
+        NS_GetSpecialDirectory(aSpecialDirName.get(), getter_AddRefs(dir));
+        if (dir) {
+          dir->GetPath(*aDirPath);
+        }
+      });
+  SyncRunnable::DispatchToThread(GetMainThreadSerialEventTarget(), runnable,
+                                 /*aForceDispatch*/ true);
+  return IPC_OK();
+}
+
+}  // namespace mozilla
diff --git a/security/sandbox/common/test/SandboxTestingParent.h b/security/sandbox/common/test/SandboxTestingParent.h
new file mode 100644
index 0000000000..5a8ef9145a
--- /dev/null
+++ b/security/sandbox/common/test/SandboxTestingParent.h
@@ -0,0 +1,53 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_SandboxTestingParent_h
+#define mozilla_SandboxTestingParent_h
+
+#include "mozilla/PSandboxTestingParent.h"
+#include "mozilla/Monitor.h"
+#include "mozilla/UniquePtr.h"
+
+#if !defined(MOZ_SANDBOX) || !defined(MOZ_DEBUG) || !defined(ENABLE_TESTS)
+#  error "This file should not be used outside of debug with tests"
+#endif
+
+namespace mozilla {
+
+class SandboxTestingThread;
+
+class SandboxTestingParent : public PSandboxTestingParent {
+ public:
+  static already_AddRefed<SandboxTestingParent> Create(
+      Endpoint<PSandboxTestingParent>&& aParentEnd);
+  static void Destroy(already_AddRefed<SandboxTestingParent> aInstance);
+
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(SandboxTestingParent, override)
+
+  void ActorDestroy(ActorDestroyReason aWhy) override;
+
+  mozilla::ipc::IPCResult RecvReportTestResults(const nsCString& testName,
+                                                bool passed,
+                                                const nsCString& resultMessage);
+  mozilla::ipc::IPCResult RecvTestCompleted();
+
+  mozilla::ipc::IPCResult RecvGetSpecialDirectory(
+      const nsCString& aSpecialDirName, nsString* aDirPath);
+
+ private:
+  explicit SandboxTestingParent(SandboxTestingThread* aThread);
+  virtual ~SandboxTestingParent();
+  void ShutdownSandboxTestThread();
+  void Bind(Endpoint<PSandboxTestingParent>&& aEnd);
+
+  UniquePtr<SandboxTestingThread> mThread;
+  Monitor mMonitor MOZ_UNANNOTATED;
+  bool mShutdownDone;
+};
+
+}  // namespace mozilla
+
+#endif  // mozilla_SandboxTestingParent_h
diff --git a/security/sandbox/common/test/SandboxTestingThread.h b/security/sandbox/common/test/SandboxTestingThread.h
new file mode 100644
index 0000000000..f85a017f94
--- /dev/null
+++ b/security/sandbox/common/test/SandboxTestingThread.h
@@ -0,0 +1,53 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_SandboxTestingThread_h
+#define mozilla_SandboxTestingThread_h
+
+#include "nsThreadManager.h"
+
+#if !defined(MOZ_SANDBOX) || !defined(MOZ_DEBUG) || !defined(ENABLE_TESTS)
+#  error "This file should not be used outside of debug with tests"
+#endif
+
+namespace mozilla {
+
+class SandboxTestingThread {
+ public:
+  void Dispatch(already_AddRefed<nsIRunnable>&& aRunnable) {
+    mThread->Dispatch(std::move(aRunnable), nsIEventTarget::NS_DISPATCH_NORMAL);
+  }
+
+  bool IsOnThread() {
+    bool on;
+    return NS_SUCCEEDED(mThread->IsOnCurrentThread(&on)) && on;
+  }
+
+  static SandboxTestingThread* Create() {
+    MOZ_RELEASE_ASSERT(NS_IsMainThread());
+    nsCOMPtr<nsIThread> thread;
+    if (NS_FAILED(
+            NS_NewNamedThread("Sandbox Testing", getter_AddRefs(thread)))) {
+      return nullptr;
+    }
+    return new SandboxTestingThread(thread);
+  }
+
+  ~SandboxTestingThread() {
+    NS_DispatchToMainThread(NewRunnableMethod("~SandboxTestingThread", mThread,
+                                              &nsIThread::Shutdown));
+  }
+
+ private:
+  explicit SandboxTestingThread(nsIThread* aThread) : mThread(aThread) {
+    MOZ_ASSERT(mThread);
+  }
+
+  nsCOMPtr<nsIThread> mThread;
+};
+}  // namespace mozilla
+
+#endif  // mozilla_SandboxTestingThread_h
diff --git a/security/sandbox/common/test/mozISandboxTest.idl b/security/sandbox/common/test/mozISandboxTest.idl
new file mode 100644
index 0000000000..7cde1defcf
--- /dev/null
+++ b/security/sandbox/common/test/mozISandboxTest.idl
@@ -0,0 +1,28 @@
+/* -*- Mode: IDL; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+// This interface is only for testing Sandbox.
+
+[scriptable, builtinclass, uuid(2306c118-3544-4674-9222-670b88dc07a9)]
+interface mozISandboxTest : nsISupports
+{
+  void startTests(in Array<ACString> aProcessesList);
+  void finishTests();
+};
+
+%{ C++
+
+#if defined(MOZ_SANDBOX) && defined(MOZ_DEBUG) && defined(ENABLE_TESTS)
+#define MOZ_SANDBOX_TEST_CID \
+  {0x989dda27, 0xb144, 0x45f9, {0x90, 0x39, 0x69, 0x74, 0x4e, 0xc6, dd0xd9, 0x12}}
+#define MOZ_SANDBOX_TEST_CONTRACTID \
+    "@mozilla.org/sandbox/sandbox-test;1"
+#else
+#error "This file should not be used outside of debug with tests"
+#endif
+%}