Bug 1696771: Always null check the ContentProcessManager singleton before use. r=smaug

Differential Revision: https://phabricator.services.mozilla.com/D143180

docshell/base/CanonicalBrowsingContext.cpp

@@ -184,6 +184,9 @@ ContentParent* CanonicalBrowsingContext::GetContentParent() const {
   }
 
   ContentProcessManager* cpm = ContentProcessManager::GetSingleton();
+  if (!cpm) {
+    return nullptr;
+  }
   return cpm->GetContentProcessById(ContentParentId(mProcessId));
 }
 

dom/base/nsFrameLoader.cpp

@@ -2750,6 +2750,9 @@ bool nsFrameLoader::TryRemoteBrowserInternal() {
     RefPtr<ContentParent> contentParent;
     if (mChildID != 0) {
       ContentProcessManager* cpm = ContentProcessManager::GetSingleton();
+      if (cpm) {
+        return false;
+      }
       contentParent = cpm->GetContentProcessById(ContentParentId(mChildID));
     }
     mRemoteBrowser =

dom/ipc/BrowserBridgeParent.cpp

@@ -83,6 +83,9 @@ nsresult BrowserBridgeParent::InitWithProcess(
   }
 
   ContentProcessManager* cpm = ContentProcessManager::GetSingleton();
+  if (!cpm) {
+    return NS_ERROR_UNEXPECTED;
+  }
   cpm->RegisterRemoteFrame(browserParent);
 
   RefPtr<WindowGlobalParent> windowParent =

dom/ipc/BrowserParent.cpp

@@ -675,7 +675,10 @@ mozilla::ipc::IPCResult BrowserParent::RecvEnsureLayersConnected(
 void BrowserParent::ActorDestroy(ActorDestroyReason why) {
   Manager()->NotifyTabDestroyed(mTabId, mMarkedDestroying);
 
-  ContentProcessManager::GetSingleton()->UnregisterRemoteFrame(mTabId);
+  ContentProcessManager* cpm = ContentProcessManager::GetSingleton();
+  if (cpm) {
+    cpm->UnregisterRemoteFrame(mTabId);
+  }
 
   if (mRemoteLayerTreeOwner.IsInitialized()) {
     auto layersId = mRemoteLayerTreeOwner.GetLayersId();

dom/ipc/ContentParent.cpp

@@ -1530,6 +1530,9 @@ already_AddRefed<RemoteBrowser> ContentParent::CreateBrowser(
   }
 
   ContentProcessManager* cpm = ContentProcessManager::GetSingleton();
+  if (NS_WARN_IF(!cpm)) {
+    return nullptr;
+  }
   cpm->RegisterRemoteFrame(browserParent);
 
   nsCOMPtr<nsIPrincipal> initialPrincipal =
@@ -2090,7 +2093,9 @@ void ContentParent::ActorDestroy(ActorDestroyReason why) {
   mSubprocess = nullptr;
 
   ContentProcessManager* cpm = ContentProcessManager::GetSingleton();
-  cpm->RemoveContentProcess(this->ChildID());
+  if (cpm) {
+    cpm->RemoveContentProcess(this->ChildID());
+  }
 
   if (mDriverCrashGuard) {
     mDriverCrashGuard->NotifyCrashed();
@@ -2481,6 +2486,8 @@ void ContentParent::AppendSandboxParams(std::vector<std::string>& aArgs) {
 bool ContentParent::BeginSubprocessLaunch(ProcessPriority aPriority) {
   AUTO_PROFILER_LABEL("ContentParent::LaunchSubprocess", OTHER);
 
+  // XXX: This check works only late, as GetSingleton will return nullptr
+  // only after ClearOnShutdown happened. See bug 1632740.
   if (!ContentProcessManager::GetSingleton()) {
     NS_WARNING(
         "Shutdown has begun, we shouldn't spawn any more child processes");
@@ -2613,7 +2620,13 @@ bool ContentParent::LaunchSubprocessResolve(bool aIsSync,
       base::GetProcId(mSubprocess->GetChildProcessHandle());
   Open(mSubprocess->TakeInitialPort(), procId);
 
-  ContentProcessManager::GetSingleton()->AddContentProcess(this);
+  ContentProcessManager* cpm = ContentProcessManager::GetSingleton();
+  if (!cpm) {
+    NS_WARNING("immediately shutting-down caused by our shutdown");
+    ShutDownProcess(SEND_SHUTDOWN_MESSAGE);
+    return false;
+  }
+  cpm->AddContentProcess(this);
 
 #ifdef MOZ_CODE_COVERAGE
   Unused << SendShareCodeCoverageMutex(
@@ -4026,7 +4039,7 @@ mozilla::ipc::IPCResult ContentParent::RecvConstructPopupBrowser(
     // window.open().
     // We need to register remote frame with the child generated tab id.
     auto* cpm = ContentProcessManager::GetSingleton();
-    if (!cpm->RegisterRemoteFrame(parent)) {
+    if (!cpm || !cpm->RegisterRemoteFrame(parent)) {
       return IPC_FAIL(this, "RegisterRemoteFrame Failed");
     }
   }
@@ -5156,9 +5169,12 @@ ContentParent::AllocPContentPermissionRequestParent(
     const IPC::Principal& aPrincipal, const IPC::Principal& aTopLevelPrincipal,
     const bool& aIsHandlingUserInput,
     const bool& aMaybeUnsafePermissionDelegate, const TabId& aTabId) {
+  RefPtr<BrowserParent> tp;
   ContentProcessManager* cpm = ContentProcessManager::GetSingleton();
-  RefPtr<BrowserParent> tp =
-      cpm->GetTopLevelBrowserParentByProcessAndTabId(this->ChildID(), aTabId);
+  if (cpm) {
+    tp =
+        cpm->GetTopLevelBrowserParentByProcessAndTabId(this->ChildID(), aTabId);
+  }
   if (!tp) {
     return nullptr;
   }
@@ -6812,9 +6828,11 @@ mozilla::ipc::IPCResult ContentParent::RecvWindowClose(
   //       browsing contexts of bc.
 
   ContentProcessManager* cpm = ContentProcessManager::GetSingleton();
-  ContentParent* cp =
-      cpm->GetContentProcessById(ContentParentId(context->OwnerProcessId()));
-  Unused << cp->SendWindowClose(context, aTrustedCaller);
+  if (cpm) {
+    ContentParent* cp =
+        cpm->GetContentProcessById(ContentParentId(context->OwnerProcessId()));
+    Unused << cp->SendWindowClose(context, aTrustedCaller);
+  }
   return IPC_OK();
 }
 
@@ -6831,9 +6849,11 @@ mozilla::ipc::IPCResult ContentParent::RecvWindowFocus(
   CanonicalBrowsingContext* context = aContext.get_canonical();
 
   ContentProcessManager* cpm = ContentProcessManager::GetSingleton();
-  ContentParent* cp =
-      cpm->GetContentProcessById(ContentParentId(context->OwnerProcessId()));
-  Unused << cp->SendWindowFocus(context, aCallerType, aActionId);
+  if (cpm) {
+    ContentParent* cp =
+        cpm->GetContentProcessById(ContentParentId(context->OwnerProcessId()));
+    Unused << cp->SendWindowFocus(context, aCallerType, aActionId);
+  }
   return IPC_OK();
 }
 
@@ -6848,9 +6868,11 @@ mozilla::ipc::IPCResult ContentParent::RecvWindowBlur(
   CanonicalBrowsingContext* context = aContext.get_canonical();
 
   ContentProcessManager* cpm = ContentProcessManager::GetSingleton();
-  ContentParent* cp =
-      cpm->GetContentProcessById(ContentParentId(context->OwnerProcessId()));
-  Unused << cp->SendWindowBlur(context, aCallerType);
+  if (cpm) {
+    ContentParent* cp =
+        cpm->GetContentProcessById(ContentParentId(context->OwnerProcessId()));
+    Unused << cp->SendWindowBlur(context, aCallerType);
+  }
   return IPC_OK();
 }
 
@@ -6868,9 +6890,11 @@ mozilla::ipc::IPCResult ContentParent::RecvRaiseWindow(
   CanonicalBrowsingContext* context = aContext.get_canonical();
 
   ContentProcessManager* cpm = ContentProcessManager::GetSingleton();
-  ContentParent* cp =
-      cpm->GetContentProcessById(ContentParentId(context->OwnerProcessId()));
-  Unused << cp->SendRaiseWindow(context, aCallerType, aActionId);
+  if (cpm) {
+    ContentParent* cp =
+        cpm->GetContentProcessById(ContentParentId(context->OwnerProcessId()));
+    Unused << cp->SendRaiseWindow(context, aCallerType, aActionId);
+  }
   return IPC_OK();
 }
 
@@ -6891,21 +6915,23 @@ mozilla::ipc::IPCResult ContentParent::RecvAdjustWindowFocus(
   processes.InsertOrUpdate(this, true);
 
   ContentProcessManager* cpm = ContentProcessManager::GetSingleton();
-  CanonicalBrowsingContext* context = aContext.get_canonical();
-  while (context) {
-    BrowsingContext* parent = context->GetParent();
-    if (!parent) {
-      break;
-    }
+  if (cpm) {
+    CanonicalBrowsingContext* context = aContext.get_canonical();
+    while (context) {
+      BrowsingContext* parent = context->GetParent();
+      if (!parent) {
+        break;
+      }
 
-    CanonicalBrowsingContext* canonicalParent = parent->Canonical();
-    ContentParent* cp = cpm->GetContentProcessById(
-        ContentParentId(canonicalParent->OwnerProcessId()));
-    if (cp && !processes.Get(cp)) {
-      Unused << cp->SendAdjustWindowFocus(context, aIsVisible, aActionId);
-      processes.InsertOrUpdate(cp, true);
+      CanonicalBrowsingContext* canonicalParent = parent->Canonical();
+      ContentParent* cp = cpm->GetContentProcessById(
+          ContentParentId(canonicalParent->OwnerProcessId()));
+      if (cp && !processes.Get(cp)) {
+        Unused << cp->SendAdjustWindowFocus(context, aIsVisible, aActionId);
+        processes.InsertOrUpdate(cp, true);
+      }
+      context = canonicalParent;
     }
-    context = canonicalParent;
   }
   return IPC_OK();
 }
@@ -6921,9 +6947,11 @@ mozilla::ipc::IPCResult ContentParent::RecvClearFocus(
   CanonicalBrowsingContext* context = aContext.get_canonical();
 
   ContentProcessManager* cpm = ContentProcessManager::GetSingleton();
-  ContentParent* cp =
-      cpm->GetContentProcessById(ContentParentId(context->OwnerProcessId()));
-  Unused << cp->SendClearFocus(context);
+  if (cpm) {
+    ContentParent* cp =
+        cpm->GetContentProcessById(ContentParentId(context->OwnerProcessId()));
+    Unused << cp->SendClearFocus(context);
+  }
   return IPC_OK();
 }
 
@@ -7046,11 +7074,11 @@ mozilla::ipc::IPCResult ContentParent::RecvSetFocusedElement(
   CanonicalBrowsingContext* context = aContext.get_canonical();
 
   ContentProcessManager* cpm = ContentProcessManager::GetSingleton();
-
-  ContentParent* cp =
-      cpm->GetContentProcessById(ContentParentId(context->OwnerProcessId()));
-  Unused << cp->SendSetFocusedElement(context, aNeedsFocus);
-
+  if (cpm) {
+    ContentParent* cp =
+        cpm->GetContentProcessById(ContentParentId(context->OwnerProcessId()));
+    Unused << cp->SendSetFocusedElement(context, aNeedsFocus);
+  }
   return IPC_OK();
 }
 
@@ -7066,11 +7094,12 @@ mozilla::ipc::IPCResult ContentParent::RecvFinalizeFocusOuter(
   LOGFOCUS(("ContentParent::RecvFinalizeFocusOuter"));
   CanonicalBrowsingContext* context = aContext.get_canonical();
   ContentProcessManager* cpm = ContentProcessManager::GetSingleton();
-
-  ContentParent* cp =
-      cpm->GetContentProcessById(ContentParentId(context->EmbedderProcessId()));
-  if (cp) {
-    Unused << cp->SendFinalizeFocusOuter(context, aCanFocus, aCallerType);
+  if (cpm) {
+    ContentParent* cp = cpm->GetContentProcessById(
+        ContentParentId(context->EmbedderProcessId()));
+    if (cp) {
+      Unused << cp->SendFinalizeFocusOuter(context, aCanFocus, aCallerType);
+    }
   }
   return IPC_OK();
 }
@@ -7111,6 +7140,9 @@ mozilla::ipc::IPCResult ContentParent::RecvBlurToParent(
       aFocusedBrowsingContext.get_canonical();
 
   ContentProcessManager* cpm = ContentProcessManager::GetSingleton();
+  if (!cpm) {
+    return IPC_OK();
+  }
 
   // If aBrowsingContextToClear and aAncestorBrowsingContextToFocusHandled
   // didn't get handled in the process that sent this IPC message and they
@@ -7158,10 +7190,11 @@ mozilla::ipc::IPCResult ContentParent::RecvMaybeExitFullscreen(
   CanonicalBrowsingContext* context = aContext.get_canonical();
 
   ContentProcessManager* cpm = ContentProcessManager::GetSingleton();
-
-  ContentParent* cp =
-      cpm->GetContentProcessById(ContentParentId(context->OwnerProcessId()));
-  Unused << cp->SendMaybeExitFullscreen(context);
+  if (cpm) {
+    ContentParent* cp =
+        cpm->GetContentProcessById(ContentParentId(context->OwnerProcessId()));
+    Unused << cp->SendMaybeExitFullscreen(context);
+  }
 
   return IPC_OK();
 }

dom/media/webrtc/transport/ipc/WebrtcTCPSocket.cpp

@@ -73,8 +73,10 @@ WebrtcTCPSocket::~WebrtcTCPSocket() {
 void WebrtcTCPSocket::SetTabId(dom::TabId aTabId) {
   MOZ_ASSERT(NS_IsMainThread());
   dom::ContentProcessManager* cpm = dom::ContentProcessManager::GetSingleton();
-  dom::ContentParentId cpId = cpm->GetTabProcessId(aTabId);
-  mAuthProvider = cpm->GetBrowserParentByProcessAndTabId(cpId, aTabId);
+  if (cpm) {
+    dom::ContentParentId cpId = cpm->GetTabProcessId(aTabId);
+    mAuthProvider = cpm->GetBrowserParentByProcessAndTabId(cpId, aTabId);
+  }
 }
 
 nsresult WebrtcTCPSocket::Write(nsTArray<uint8_t>&& aWriteData) {

gfx/ipc/CrossProcessPaint.cpp

@@ -367,13 +367,18 @@ void CrossProcessPaint::LostFragment(dom::WindowGlobalParent* aWGP) {
 
 void CrossProcessPaint::QueueDependencies(
     const nsTHashSet<uint64_t>& aDependencies) {
+  dom::ContentProcessManager* cpm = dom::ContentProcessManager::GetSingleton();
+  if (!cpm) {
+    CPP_LOG(
+        "Skipping QueueDependencies with no"
+        " current ContentProcessManager.\n");
+    return;
+  }
   for (const auto& key : aDependencies) {
     auto dependency = dom::TabId(key);
 
     // Get the current BrowserParent of the remote browser that was marked
     // as a dependency
-    dom::ContentProcessManager* cpm =
-        dom::ContentProcessManager::GetSingleton();
     dom::ContentParentId cpId = cpm->GetTabProcessId(dependency);
     RefPtr<dom::BrowserParent> browser =
         cpm->GetBrowserParentByProcessAndTabId(cpId, dependency);