[wasm] Remove a long-living CodeSpaceWriteScope

The {CodeSpaceWriteScope} in {InstanceBuilder::Build} was kept open
while processing imports, which could compile another wasm module via
{compiler::ResolveWasmImportCall} and
{WasmEngine::SyncCompileTranslatedAsmJs}. This leads to errors since
{CodeSpaceWriteScope}s for different modules cannot be held open at the
same time.

This CL fixes that by only opening the {CodeSpaceWriteScope} for the
actual compilation of import wrappers.

Drive-by: Only call {ProcessImports} if there are imports to be
processed, to avoid some of the overhead of {ProcessImports} and
{CompileImportWrappers}.

R=jkummerow@chromium.org

Bug: chromium:1239522
Change-Id: Ifbaf64a4be92088ae4a3fd7e9700a33397b2a967
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3097283
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#76311}

src/wasm/module-instantiate.cc

@@ -65,6 +65,7 @@ class CompileImportWrapperJob final : public JobTask {
   }
 
   void Run(JobDelegate* delegate) override {
+    CodeSpaceWriteScope code_space_write_scope(native_module_);
     while (base::Optional<WasmImportWrapperCache::CacheKey> key =
                queue_->pop()) {
       CompileImportWrapper(native_module_, counters_, key->kind, key->signature,
@@ -385,7 +386,7 @@ class InstanceBuilder {
 
   // Process the imports, including functions, tables, globals, and memory, in
   // order, loading them from the {ffi_} object. Returns the number of imported
-  // functions.
+  // functions, or {-1} on error.
   int ProcessImports(Handle<WasmInstanceObject> instance);
 
   template <typename T>
@@ -638,14 +639,14 @@ MaybeHandle<WasmInstanceObject> InstanceBuilder::Build() {
     instance->set_indirect_function_tables(*tables);
   }
 
-  CodeSpaceWriteScope native_modification_scope(native_module);
-
   //--------------------------------------------------------------------------
   // Process the imports for the module.
   //--------------------------------------------------------------------------
-  int num_imported_functions = ProcessImports(instance);
-  if (num_imported_functions < 0) return {};
-  wasm_module_instantiated.imported_function_count = num_imported_functions;
+  if (!module_->import_table.empty()) {
+    int num_imported_functions = ProcessImports(instance);
+    if (num_imported_functions < 0) return {};
+    wasm_module_instantiated.imported_function_count = num_imported_functions;
+  }
 
   //--------------------------------------------------------------------------
   // Create maps for managed objects (GC proposal).

test/mjsunit/regress/wasm/regress-1239522.js

+// 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.
+
+var asm = function(global) {
+  'use asm';
+  function f() {}
+  return f;
+};
+function asm2(global, imports) {
+  'use asm';
+  var asm = imports.asm;
+  function f() {}
+  return {f: f};
+}
+asm2(this, {asm: asm});