tor-browser

commit 195873d7f314e2e03c04be36fda58483cb5919b3
parent c3e0176a09450e8a87c029c0cbdec0fca8f87a26
Author: Nika Layzell <nika@thelayzells.com>
Date:   Tue, 16 Dec 2025 04:53:47 +0000

Bug 1927599 - Part 5: Disable JIT on iOS in LockdownMode, r=glandium

Differential Revision: https://phabricator.services.mozilla.com/D229402

Diffstat:
M
xpcom/build/XPCOMInit.cpp
 | 
21
+++++++++++++++++++++

1 file changed, 21 insertions(+), 0 deletions(-)
diff --git a/xpcom/build/XPCOMInit.cpp b/xpcom/build/XPCOMInit.cpp
@@ -110,6 +110,10 @@
 
 #include "mozilla/GeckoTrace.h"
 
+#ifdef XP_IOS
+#  include <CoreFoundation/CoreFoundation.h>
+#endif
+
 using base::AtExitManager;
 using mozilla::ipc::IOThreadParent;
 
@@ -221,6 +225,18 @@ class OggReporter final : public nsIMemoryReporter,
 
 NS_IMPL_ISUPPORTS(OggReporter, nsIMemoryReporter)
 
+#ifdef XP_IOS
+// Check if iOS LockdownMode is enabled, which blocks the JIT everywhere.
+static bool IsLockdownModeEnabled() {
+  CFPropertyListRef prefValue = CFPreferencesCopyValue(
+      CFSTR("LDMGlobalEnabled"), kCFPreferencesAnyApplication,
+      kCFPreferencesCurrentUser, kCFPreferencesAnyHost);
+  bool enabled = prefValue == kCFBooleanTrue;
+  if (prefValue) CFRelease(prefValue);
+  return enabled;
+}
+#endif
+
 static bool sInitializedJS = false;
 
 static void InitializeJS() {
@@ -235,6 +251,11 @@ static void InitializeJS() {
       mozilla::StaticPrefs::javascript_options_main_process_disable_jit()) {
     JS::DisableJitBackend();
   }
+#ifdef XP_IOS
+  else if (IsLockdownModeEnabled()) {
+    JS::DisableJitBackend();
+  }
+#endif
 
   // Set all JS::Prefs.
   SET_JS_PREFS_FROM_BROWSER_PREFS;