src,test: disable freezing V8 flags on initialization

Node.js still changes flags after initializationg; either because tests need to set their own flags (which V8 tests also still allow), or because it's explicitly requested via the "v8.setFlagsFromString" method that Node.js provides. PR-URL: #44741 Reviewed-By: Ben Noordhuis <[email protected]> Reviewed-By: Jiawen Geng <[email protected]> Reviewed-By: James M Snell <[email protected]>
nodejs · Oct 11, 2022 · 2e49b99 · 2e49b99
1 parent fd52c62
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diff --git a/src/node.cc b/src/node.cc
@@ -741,6 +741,11 @@ static ExitCode InitializeNodeWithArgsInternal(
   // used in diagnostic reports.
   per_process::cli_options->cmdline = *argv;
 
+  // Node provides a "v8.setFlagsFromString" method to dynamically change flags.
+  // Hence do not freeze flags when initializing V8. In a browser setting, this
+  // is security relevant, for Node it's less important.
+  V8::SetFlagsFromString("--no-freeze-flags-after-init");
+
 #if defined(NODE_V8_OPTIONS)
   // Should come before the call to V8::SetFlagsFromCommandLine()
   // so the user can disable a flag --foo at run-time by passing

diff --git a/test/cctest/node_test_fixture.cc b/test/cctest/node_test_fixture.cc
@@ -24,6 +24,11 @@ void NodeTestEnvironment::SetUp() {
 #endif
   cppgc::InitializeProcess(
       NodeZeroIsolateTestFixture::platform->GetPageAllocator());
+
+  // Before initializing V8, disable the --freeze-flags-after-init flag, so
+  // individual tests can set their own flags.
+  v8::V8::SetFlagsFromString("--no-freeze-flags-after-init");
+
   v8::V8::Initialize();
 }