From 2404f063433064e90059e6b3153f663e10d1f884 Mon Sep 17 00:00:00 2001
From: p0358 <p0358@users.noreply.github.com>
Date: Thu, 30 Dec 2021 04:47:16 +0100
Subject: add realloc too

---
 LauncherInjector/memalloc.cpp | 25 +++++++++++++++++++++++++
 LauncherInjector/memalloc.h   | 15 ++++++++++++---
 2 files changed, 37 insertions(+), 3 deletions(-)

(limited to 'LauncherInjector')

diff --git a/LauncherInjector/memalloc.cpp b/LauncherInjector/memalloc.cpp
index 1d0f13e6..936523d7 100644
--- a/LauncherInjector/memalloc.cpp
+++ b/LauncherInjector/memalloc.cpp
@@ -17,6 +17,7 @@ void LoadTier0Handle()
 const int STATIC_ALLOC_SIZE = 16384;
 
 size_t g_iStaticAllocated = 0;
+void* g_pLastAllocated = nullptr;
 char pStaticAllocBuf[STATIC_ALLOC_SIZE];
 
 // they should never be used here, except in LibraryLoadError // haha not true
@@ -29,6 +30,7 @@ void* malloc(size_t n)
     {
         void* ret = pStaticAllocBuf + g_iStaticAllocated;
         g_iStaticAllocated += n;
+        g_pLastAllocated = ret;
         return ret;
     }
     else
@@ -53,6 +55,29 @@ void free(void* p)
         (*g_ppMemAllocSingleton)->m_vtable->Free(*g_ppMemAllocSingleton, p);
 }
 
+void* realloc(void* old_ptr, size_t size) {
+    // it was allocated into the static buffer
+    if (old_ptr >= pStaticAllocBuf && old_ptr <= pStaticAllocBuf + STATIC_ALLOC_SIZE)
+    {
+        if (g_pLastAllocated == old_ptr)
+        {
+            // nothing was allocated after this
+            size_t old_size = g_iStaticAllocated - ((size_t)g_pLastAllocated - (size_t)pStaticAllocBuf);
+            size_t diff = size - old_size;
+            if (diff > 0)
+                g_iStaticAllocated += diff;
+            return old_ptr;
+        }
+        else
+        {
+            return malloc(size);
+        }
+    }
+
+    if (g_ppMemAllocSingleton && *g_ppMemAllocSingleton)
+        return (*g_ppMemAllocSingleton)->m_vtable->Realloc(*g_ppMemAllocSingleton, old_ptr, size);
+}
+
 void* operator new(size_t n)
 {
     return malloc(n);
diff --git a/LauncherInjector/memalloc.h b/LauncherInjector/memalloc.h
index 928e403c..c983966c 100644
--- a/LauncherInjector/memalloc.h
+++ b/LauncherInjector/memalloc.h
@@ -5,10 +5,19 @@ class IMemAlloc
 public:
     struct VTable
     {
-        void* unknown[1];
+        void* unknown[1]; // alloc debug
         void* (*Alloc) (IMemAlloc* memAlloc, size_t nSize);
-        void* unknown2[3];
-        void(*Free) (IMemAlloc* memAlloc, void* pMem);
+        void* unknown2[1]; // realloc debug
+        void* (*Realloc)(IMemAlloc* memAlloc, void* pMem, size_t nSize);
+        void* unknown3[1]; // free #1
+        void (*Free) (IMemAlloc* memAlloc, void* pMem);
+        void* unknown4[2]; // nullsubs, maybe CrtSetDbgFlag
+        size_t(*GetSize) (IMemAlloc* memAlloc, void* pMem);
+        void* unknown5[9]; // they all do literally nothing
+        void (*DumpStats) (IMemAlloc* memAlloc);
+        void (*DumpStatsFileBase) (IMemAlloc* memAlloc, const char* pchFileBase);
+        void* unknown6[4];
+        int (*heapchk) (IMemAlloc* memAlloc);
     };
 
     VTable* m_vtable;
-- 
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