3 files changed, 20 insertions, 0 deletions
diff --git a/Userland/Libraries/LibC/crt0.cpp b/Userland/Libraries/LibC/crt0.cpp
index 798f7c751b..f8bb061456 100644
--- a/Userland/Libraries/LibC/crt0.cpp
+++ b/Userland/Libraries/LibC/crt0.cpp
@@ -15,6 +15,7 @@
 extern "C" {
 
 extern size_t __stack_chk_guard;
+extern bool s_global_initializers_ran;
 
 int main(int, char**, char**);
 
@@ -41,6 +42,8 @@ int _entry(int argc, char** argv, char** env)
     __environ_is_malloced = false;
     __begin_atexit_locking();
 
+    s_global_initializers_ran = true;
+
     _init();
 
     int status = main(argc, argv, environ);
diff --git a/Userland/Libraries/LibC/libcinit.cpp b/Userland/Libraries/LibC/libcinit.cpp
index 09d81cbac4..38cab1bdaa 100644
--- a/Userland/Libraries/LibC/libcinit.cpp
+++ b/Userland/Libraries/LibC/libcinit.cpp
@@ -19,6 +19,7 @@ __thread int errno;
 char** environ;
 bool __environ_is_malloced;
 bool __stdio_is_initialized;
+bool s_global_initializers_ran;
 void* __auxiliary_vector;
 
 static void __auxiliary_vector_init();
diff --git a/Userland/Libraries/LibCore/EventLoop.cpp b/Userland/Libraries/LibCore/EventLoop.cpp
index 7fe465ceeb..b7f6c109a7 100644
--- a/Userland/Libraries/LibCore/EventLoop.cpp
+++ b/Userland/Libraries/LibCore/EventLoop.cpp
@@ -35,6 +35,10 @@
 #include <time.h>
 #include <unistd.h>
 
+#ifdef __serenity__
+extern bool s_global_initializers_ran;
+#endif
+
 namespace Core {
 
 class InspectorServerConnection;
@@ -284,6 +288,18 @@ private:
 EventLoop::EventLoop([[maybe_unused]] MakeInspectable make_inspectable)
     : m_private(make<Private>())
 {
+#ifdef __serenity__
+    if (!s_global_initializers_ran) {
+        // NOTE: Trying to have an event loop as a global variable will lead to initialization-order fiascos,
+        //       as the event loop constructor accesses and/or sets other global variables.
+        //       Therefore, we crash the program before ASAN catches us.
+        //       If you came here because of the assertion failure, please redesign your program to not have global event loops.
+        //       The common practice is to initialize the main event loop in the main function, and if necessary,
+        //       pass event loop references around or access them with EventLoop::with_main_locked() and EventLoop::current().
+        VERIFY_NOT_REACHED();
+    }
+#endif
+
     if (!s_event_loop_stack) {
         s_event_loop_stack = new Vector<EventLoop&>;
         s_timers = new HashMap<int, NonnullOwnPtr<EventLoopTimer>>;