Wipe stack before booting into the application

wumsloader/src/entry.cpp

@@ -11,6 +11,7 @@
 #include "utils/utils.h"
 #include "version.h"
 #include <coreinit/debug.h>
+#include <coreinit/interrupts.h>
 #include <coreinit/kernel.h>
 #include <coreinit/memexpheap.h>
 #include <cstdint>
@@ -23,6 +24,25 @@ void CallInitHooksForModule(const std::shared_ptr<ModuleData> &curModule);
 bool CheckModulesByDependencies(const std::vector<std::shared_ptr<ModuleData>> &loadedModules);
 std::vector<std::shared_ptr<ModuleData>> OrderModulesByDependencies(const std::vector<std::shared_ptr<ModuleData>> &loadedModules);
 
+void wipeStack(void *stackEnd) {
+    volatile char current_stack_marker = 0;
+    volatile char *wipePtr             = static_cast<volatile char *>(stackEnd) + 16;
+    const char *safeLimit              = reinterpret_cast<char *>(reinterpret_cast<uintptr_t>(&current_stack_marker) - 256);
+
+    if (wipePtr >= safeLimit) {
+        return;
+    }
+
+    const auto state = OSDisableInterrupts();
+    while (const_cast<char *>(wipePtr) < safeLimit) {
+        *wipePtr = 0;
+        wipePtr++;
+    }
+
+    OSRestoreInterrupts(state);
+}
+
+
 // We need to wrap it to make sure the main function is called AFTER our code.
 // The compiler tries to optimize this otherwise and calling the main function earlier
 extern "C" int _start(int argc, char **argv) {
@@ -44,6 +64,11 @@ extern "C" int _start(int argc, char **argv) {
         doStart(argc, argv);
     }
 
+    // Some games like TNT Racers (00050000-10142800) have parts of the games state on the stack with uninitialized fields.
+    // Usually the stack is completely empty when booting into a game, but our modules/plugins run on the same thread, leaving "garbage"" on the (unused) stack.
+    // To make sure the stack is as clean as possible, we want to clear it
+    wipeStack(OSGetCurrentThread()->stackEnd);
+
     KernelInfo0 kernelInfo0;
     __KernelGetInfo0(&kernelInfo0, 0);
     asm(

wumsloader/src/utils/imports.h

@@ -56,6 +56,8 @@ IMPORT(OSFastCond_Signal);
 IMPORT(OSFastMutex_Unlock);
 IMPORT(OSInitSpinLock);
 IMPORT(OSGetAlarmUserData);
+IMPORT(OSRestoreInterrupts);
+IMPORT(OSDisableInterrupts);
 
 IMPORT(FSTimeToCalendarTime);
 IMPORT(FSInit);