tor-browser

commit 26107c4f63741a94b958b19cb54be1c5c01c075e
parent dab845c9edf7165672bd6dbb8e8a28763ab379f9
Author: Daniel Minor <dminor@mozilla.com>
Date:   Fri, 12 Dec 2025 14:12:36 +0000

Bug 1994828 - Don't cache wasm modules; r=arai

Differential Revision: https://phabricator.services.mozilla.com/D275506

Diffstat:
M
dom/script/ScriptLoader.cpp
 | 
41
++++++++++++++++++++++++++++++++---------

1 file changed, 32 insertions(+), 9 deletions(-)
diff --git a/dom/script/ScriptLoader.cpp b/dom/script/ScriptLoader.cpp
@@ -2775,15 +2775,33 @@ void ScriptLoader::CalculateCacheFlag(ScriptLoadRequest* aRequest) {
     return;
   }
 
-  if (aRequest->IsModuleRequest() &&
-      aRequest->AsModuleRequest()->mModuleType != JS::ModuleType::JavaScript) {
-    LOG(("ScriptLoadRequest (%p): Bytecode-cache: Skip all: JSON module",
-         aRequest));
-    aRequest->MarkNotCacheable();
-    MOZ_ASSERT(!aRequest->getLoadedScript()->HasDiskCacheReference());
-    MOZ_ASSERT_IF(aRequest->IsTextSource(),
-                  aRequest->HasNoSRIOrSRIAndSerializedStencil());
-    return;
+  if (aRequest->IsModuleRequest()) {
+    ModuleLoadRequest* moduleLoadRequest = aRequest->AsModuleRequest();
+    if (moduleLoadRequest->mModuleType == JS::ModuleType::JavaScriptOrWasm) {
+#ifdef NIGHTLY_BUILD
+      // See https://bugzilla.mozilla.org/show_bug.cgi?id=1998240
+      // For now, we don't support caching wasm modules.
+      if (moduleLoadRequest->HasWasmMimeTypeEssence()) {
+        LOG(("ScriptLoadRequest (%p): Bytecode-cache: Skip all: wasm module",
+             aRequest));
+        aRequest->MarkNotCacheable();
+        // The disk reference is cleared when we do the mime essense check
+        // in PrepareLoadedRequest.
+        MOZ_ASSERT(!aRequest->getLoadedScript()->HasDiskCacheReference());
+        MOZ_ASSERT_IF(aRequest->IsTextSource(),
+                      aRequest->HasNoSRIOrSRIAndSerializedStencil());
+        return;
+      }
+#endif
+    } else {
+      LOG(("ScriptLoadRequest (%p): Bytecode-cache: Skip all: synthetic module",
+           aRequest));
+      aRequest->MarkNotCacheable();
+      MOZ_ASSERT(!aRequest->getLoadedScript()->HasDiskCacheReference());
+      MOZ_ASSERT_IF(aRequest->IsTextSource(),
+                    aRequest->HasNoSRIOrSRIAndSerializedStencil());
+      return;
+    }
   }
 
   if (!aRequest->IsCachedStencil() && aRequest->ExpirationTime().IsExpired()) {
@@ -4630,6 +4648,11 @@ nsresult ScriptLoader::PrepareLoadedRequest(ScriptLoadRequest* aRequest,
           if (nsContentUtils::HasWasmMimeTypeEssence(
                   NS_ConvertUTF8toUTF16(mimeType))) {
             aRequest->AsModuleRequest()->SetHasWasmMimeTypeEssence();
+            // See https://bugzilla.mozilla.org/show_bug.cgi?id=1998240
+            // For now, we don't support caching wasm modules. We enable
+            // caching in ScriptLoader::OnStreamComplete for
+            // text streams prior to reaching the mime type check.
+            aRequest->getLoadedScript()->DropDiskCacheReferenceAndSRI();
           }
         }
       }