From 665ff99504ab85f209bbec75a56f2465af5ac277 Mon Sep 17 00:00:00 2001
From: momo5502 <mauriceheumann@gmail.com>
Date: Fri, 14 Feb 2025 14:10:35 +0100
Subject: [PATCH] Some GDI fixes

---
 src/common/platform/kernel_mapped.hpp   |  2 +-
 src/common/platform/process.hpp         |  5 ++++
 src/windows-emulator/emulator_utils.hpp | 32 ++++++++++++++++++++-----
 src/windows-emulator/syscalls.cpp       | 10 ++++++--
 4 files changed, 40 insertions(+), 9 deletions(-)

diff --git a/src/common/platform/kernel_mapped.hpp b/src/common/platform/kernel_mapped.hpp
index 9a18cb21..2dae3215 100644
--- a/src/common/platform/kernel_mapped.hpp
+++ b/src/common/platform/kernel_mapped.hpp
@@ -289,7 +289,7 @@ typedef struct _PEB64
     ULONG MaximumNumberOfHeaps;
     std::uint64_t** ProcessHeaps; // PHEAP
 
-    std::uint64_t* GdiSharedHandleTable; // PGDI_SHARED_MEMORY
+    std::uint64_t GdiSharedHandleTable; // PGDI_SHARED_MEMORY
     std::uint64_t* ProcessStarterHelper;
     ULONG GdiDCAttributeList;
 
diff --git a/src/common/platform/process.hpp b/src/common/platform/process.hpp
index 1c057788..8b989f65 100644
--- a/src/common/platform/process.hpp
+++ b/src/common/platform/process.hpp
@@ -846,8 +846,13 @@ struct GDI_HANDLE_ENTRY64
 struct GDI_SHARED_MEMORY64
 {
     GDI_HANDLE_ENTRY64 Handles[GDI_MAX_HANDLE_COUNT];
+    char pad[0xC8];
+    uint64_t Objects[0x20];
+    uint64_t Data[0x200]; // ?
 };
 
+static_assert(offsetof(GDI_SHARED_MEMORY64, Objects) == 0x1800B0);
+
 struct CLIENT_ID64
 {
     DWORD64 UniqueProcess;
diff --git a/src/windows-emulator/emulator_utils.hpp b/src/windows-emulator/emulator_utils.hpp
index dfe5e5c6..11d87d01 100644
--- a/src/windows-emulator/emulator_utils.hpp
+++ b/src/windows-emulator/emulator_utils.hpp
@@ -117,14 +117,24 @@ class emulator_object
     }
 
     template <typename F>
-    void access(const F& accessor, const size_t index = 0) const
+    void access_safe(const F& accessor, const size_t index = 0) const
     {
-        T obj{};
-        this->memory_->read_memory(this->address_ + index * this->size(), &obj, sizeof(obj));
-
-        accessor(obj);
+        auto obj = std::make_unique<T>();
+        this->access_object(accessor, *obj, index);
+    }
 
-        this->write(obj, index);
+    template <typename F>
+    void access(const F& accessor, const size_t index = 0) const
+    {
+        if constexpr (sizeof(T) < 0x4000)
+        {
+            T obj{};
+            this->access_object(accessor, obj, index);
+        }
+        else
+        {
+            this->access_safe(accessor, index);
+        }
     }
 
     void serialize(utils::buffer_serializer& buffer) const
@@ -145,6 +155,16 @@ class emulator_object
   private:
     memory_interface* memory_{};
     uint64_t address_{};
+
+    template <typename F>
+    void access_object(const F& accessor, T& obj, const size_t index = 0) const
+    {
+        this->memory_->read_memory(this->address_ + index * this->size(), &obj, sizeof(obj));
+
+        accessor(obj);
+
+        this->write(obj, index);
+    }
 };
 
 // TODO: warning emulator_utils is hardcoded for 64bit unicode_string usage
diff --git a/src/windows-emulator/syscalls.cpp b/src/windows-emulator/syscalls.cpp
index c539d4c3..98c2d45b 100644
--- a/src/windows-emulator/syscalls.cpp
+++ b/src/windows-emulator/syscalls.cpp
@@ -2669,8 +2669,14 @@ namespace
         c.proc.peb.access([&](PEB64& peb) {
             if (!peb.GdiSharedHandleTable)
             {
-                peb.GdiSharedHandleTable = reinterpret_cast<EmulatorTraits<Emu64>::PVOID*>(
-                    c.proc.base_allocator.reserve<GDI_SHARED_MEMORY64>().ptr());
+                const auto shared_memory = c.proc.base_allocator.reserve<GDI_SHARED_MEMORY64>();
+
+                shared_memory.access([](GDI_SHARED_MEMORY64& mem) {
+                    mem.Objects[0x12] = 1;
+                    mem.Objects[0x13] = 1;
+                });
+
+                peb.GdiSharedHandleTable = shared_memory.value();
             }
         });