bootstrap: split NodeMainInstance::Run() and move handle checking code to the snapshot builder

src/node_main_instance.cc

@@ -132,21 +132,24 @@ int NodeMainInstance::Run(const EnvSerializeInfo* env_info) {
   int exit_code = 0;
   DeleteFnPtr<Environment, FreeEnvironment> env =
       CreateMainEnvironment(&exit_code, env_info);
-
   CHECK_NOT_NULL(env);
-  {
-    Context::Scope context_scope(env->context());
 
-    if (exit_code == 0) {
-      LoadEnvironment(env.get(), StartExecutionCallback{});
+  Context::Scope context_scope(env->context());
+  Run(&exit_code, env.get());
+  return exit_code;
+}
 
-      exit_code = SpinEventLoop(env.get()).FromMaybe(1);
-    }
+void NodeMainInstance::Run(int* exit_code, Environment* env) {
+  if (*exit_code == 0) {
+    LoadEnvironment(env, StartExecutionCallback{});
 
-    ResetStdio();
+    *exit_code = SpinEventLoop(env).FromMaybe(1);
+  }
 
-    // TODO(addaleax): Neither NODE_SHARED_MODE nor HAVE_INSPECTOR really
-    // make sense here.
+  ResetStdio();
+
+  // TODO(addaleax): Neither NODE_SHARED_MODE nor HAVE_INSPECTOR really
+  // make sense here.
 #if HAVE_INSPECTOR && defined(__POSIX__) && !defined(NODE_SHARED_MODE)
   struct sigaction act;
   memset(&act, 0, sizeof(act));
@@ -161,9 +164,6 @@ int NodeMainInstance::Run(const EnvSerializeInfo* env_info) {
 #if defined(LEAK_SANITIZER)
   __lsan_do_leak_check();
 #endif
-  }
-
-  return exit_code;
 }
 
 DeleteFnPtr<Environment, FreeEnvironment>
@@ -224,8 +224,6 @@ NodeMainInstance::CreateMainEnvironment(int* exit_code,
     }
   }
 
-  CHECK(env->req_wrap_queue()->IsEmpty());
-  CHECK(env->handle_wrap_queue()->IsEmpty());
   return env;
 }
 

src/node_main_instance.h

@@ -59,6 +59,7 @@ class NodeMainInstance {
 
   // Start running the Node.js instances, return the exit code when finished.
   int Run(const EnvSerializeInfo* env_info);
+  void Run(int* exit_code, Environment* env);
 
   IsolateData* isolate_data() { return isolate_data_.get(); }
 

src/node_snapshotable.cc

@@ -157,7 +157,21 @@ void SnapshotBuilder::Generate(SnapshotData* out,
     // Must be out of HandleScope
     out->blob =
         creator.CreateBlob(SnapshotCreator::FunctionCodeHandling::kClear);
+
+    // We must be able to rehash the blob when we restore it or otherwise
+    // the hash seed would be fixed by V8, introducing a vulnerability.
     CHECK(out->blob.CanBeRehashed());
+
+    // We cannot resurrect the handles from the snapshot, so make sure that
+    // no handles are left open in the environment after the blob is created
+    // (which should trigger a GC and close all handles that can be closed).
+    if (!env->req_wrap_queue()->IsEmpty() || !env->handle_wrap_queue()->IsEmpty()
+        || per_process::enabled_debug_list.enabled(DebugCategory::MKSNAPSHOT)) {
+      PrintLibuvHandleInformation(env->event_loop(), stderr);
+    }
+    CHECK(env->req_wrap_queue()->IsEmpty());
+    CHECK(env->handle_wrap_queue()->IsEmpty());
+
     // Must be done while the snapshot creator isolate is entered i.e. the
     // creator is still alive.
     FreeEnvironment(env);