From 1f7d853d655215a667ad696847aaf06ab77369c7 Mon Sep 17 00:00:00 2001
From: Maschell <Maschell@gmx.de>
Date: Sun, 26 Mar 2023 15:55:36 +0200
Subject: [PATCH] Memset every buffer allocated on the default heap before
 freeing

---
 wumsloader/src/fs/FileUtils.cpp             | 5 ++---
 wumsloader/src/module/ModuleDataFactory.cpp | 7 ++++++-
 wumsloader/src/utils/utils.h                | 2 ++
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/wumsloader/src/fs/FileUtils.cpp b/wumsloader/src/fs/FileUtils.cpp
index 9bb10fa..5746b49 100644
--- a/wumsloader/src/fs/FileUtils.cpp
+++ b/wumsloader/src/fs/FileUtils.cpp
@@ -1,4 +1,5 @@
 #include "utils/logger.h"
+#include "utils/utils.h"
 #include <coreinit/memdefaultheap.h>
 #include <cstdint>
 #include <fcntl.h>
@@ -6,9 +7,6 @@
 #include <string>
 #include <unistd.h>
 
-#define ROUNDDOWN(val, align) ((val) & ~(align - 1))
-#define ROUNDUP(val, align)   ROUNDDOWN(((val) + (align - 1)), align)
-
 int32_t LoadFileToMem(const std::string &filepath, uint8_t **inbuffer, uint32_t *size) {
     //! always initialze input
     *inbuffer = nullptr;
@@ -47,6 +45,7 @@ int32_t LoadFileToMem(const std::string &filepath, uint8_t **inbuffer, uint32_t
     ::close(iFd);
 
     if (done != filesize) {
+        memset(buffer, 0, ROUNDUP(filesize, 0x40));
         free(buffer);
         buffer = nullptr;
         return -3;
diff --git a/wumsloader/src/module/ModuleDataFactory.cpp b/wumsloader/src/module/ModuleDataFactory.cpp
index 723e7a4..62e2d1d 100644
--- a/wumsloader/src/module/ModuleDataFactory.cpp
+++ b/wumsloader/src/module/ModuleDataFactory.cpp
@@ -45,7 +45,12 @@ std::optional<std::shared_ptr<ModuleData>> ModuleDataFactory::load(const std::st
         return {};
     }
 
-    auto cleanupBuffer = onLeavingScope([buffer]() { MEMFreeToDefaultHeap(buffer); });
+    auto cleanupBuffer = onLeavingScope([buffer, fsize]() {
+        // Some games (e.g. Minecraft) expect the default heap to be empty.
+        // Make sure to clean up the memory after using it
+        memset(buffer, 0, ROUNDUP(fsize, 0x40));
+        MEMFreeToDefaultHeap(buffer);
+    });
 
     // Load ELF data
     if (!reader.load(reinterpret_cast<char *>(buffer), fsize)) {
diff --git a/wumsloader/src/utils/utils.h b/wumsloader/src/utils/utils.h
index e7357b8..f25451e 100644
--- a/wumsloader/src/utils/utils.h
+++ b/wumsloader/src/utils/utils.h
@@ -2,6 +2,8 @@
 #include <memory>
 #include <vector>
 
+#define ROUNDDOWN(val, align) ((val) & ~(align - 1))
+#define ROUNDUP(val, align)   ROUNDDOWN(((val) + (align - 1)), align)
 
 template<class T, class... Args>
 std::unique_ptr<T> make_unique_nothrow(Args &&...args) noexcept(noexcept(T(std::forward<Args>(args)...))) {