From 46b28fd25b5992fe654966452d71d69f7bb07143 Mon Sep 17 00:00:00 2001
From: "Daniel R." <47796739+polybiusproxy@users.noreply.github.com>
Date: Thu, 11 Jul 2024 14:16:10 +0200
Subject: [PATCH] Fix bug where files were always mapped as read only.

---
 src/common/io_file.cpp     | 13 +++++++++++--
 src/core/address_space.cpp | 17 +++++++++++++++--
 src/core/address_space.h   |  2 +-
 src/core/memory.cpp        |  2 +-
 4 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/src/common/io_file.cpp b/src/common/io_file.cpp
index 3d60d5b4f..63b036574 100644
--- a/src/common/io_file.cpp
+++ b/src/common/io_file.cpp
@@ -246,9 +246,18 @@ uintptr_t IOFile::GetFileMapping() {
     }
 #ifdef _WIN64
     const int fd = fileno(file);
+
     HANDLE hfile = reinterpret_cast<HANDLE>(_get_osfhandle(fd));
-    HANDLE mapping =
-        CreateFileMapping2(hfile, NULL, FILE_MAP_READ, PAGE_READONLY, SEC_COMMIT, 0, NULL, NULL, 0);
+    HANDLE mapping = nullptr;
+
+    if (file_access_mode == FileAccessMode::ReadWrite) {
+        mapping = CreateFileMapping2(hfile, NULL, FILE_MAP_WRITE, PAGE_READWRITE, SEC_COMMIT,
+                                            0, NULL, NULL, 0);
+    } else {
+        mapping = CreateFileMapping2(hfile, NULL, FILE_MAP_READ, PAGE_READONLY, SEC_COMMIT,
+                                            0, NULL, NULL, 0);
+    }
+    
     file_mapping = std::bit_cast<uintptr_t>(mapping);
     ASSERT_MSG(file_mapping, "{}", Common::GetLastErrorMsg());
     return file_mapping;
diff --git a/src/core/address_space.cpp b/src/core/address_space.cpp
index 7749ec2dd..8a07edcfc 100644
--- a/src/core/address_space.cpp
+++ b/src/core/address_space.cpp
@@ -5,6 +5,7 @@
 #include "common/assert.h"
 #include "common/error.h"
 #include "core/address_space.h"
+#include "core/memory.h"
 #include "core/libraries/kernel/memory_management.h"
 
 #ifdef _WIN32
@@ -18,6 +19,18 @@ namespace Core {
 
 static constexpr size_t BackingSize = SCE_KERNEL_MAIN_DMEM_SIZE;
 
+[[nodiscard]] constexpr u64 ToWindowsProt(Core::MemoryProt prot) {
+    switch (prot) {
+    case Core::MemoryProt::NoAccess:
+    default:
+        return PAGE_NOACCESS;
+    case Core::MemoryProt::CpuRead:
+        return PAGE_READONLY;
+    case Core::MemoryProt::CpuReadWrite:
+        return PAGE_READWRITE;
+    }
+}
+
 #ifdef _WIN32
 struct AddressSpace::Impl {
     Impl() : process{GetCurrentProcess()} {
@@ -325,8 +338,8 @@ void* AddressSpace::Map(VAddr virtual_addr, size_t size, u64 alignment, PAddr ph
                      is_exec ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE);
 }
 
-void* AddressSpace::MapFile(VAddr virtual_addr, size_t size, size_t offset, uintptr_t fd) {
-    return impl->Map(virtual_addr, offset, size, fd ? PAGE_READONLY : PAGE_READWRITE, fd);
+void* AddressSpace::MapFile(VAddr virtual_addr, size_t size, size_t offset, u32 prot, uintptr_t fd) {
+    return impl->Map(virtual_addr, offset, size, ToWindowsProt(std::bit_cast<Core::MemoryProt>(prot)), fd);
 }
 
 void AddressSpace::Unmap(VAddr virtual_addr, size_t size, bool has_backing) {
diff --git a/src/core/address_space.h b/src/core/address_space.h
index b979481f7..5b68839c0 100644
--- a/src/core/address_space.h
+++ b/src/core/address_space.h
@@ -63,7 +63,7 @@ public:
               bool exec = false);
 
     /// Memory maps a specified file descriptor.
-    void* MapFile(VAddr virtual_addr, size_t size, size_t offset, uintptr_t fd);
+    void* MapFile(VAddr virtual_addr, size_t size, size_t offset, u32 prot, uintptr_t fd);
 
     /// Unmaps specified virtual memory area.
     void Unmap(VAddr virtual_addr, size_t size, bool has_backing);
diff --git a/src/core/memory.cpp b/src/core/memory.cpp
index 2f1f99d35..98628ee40 100644
--- a/src/core/memory.cpp
+++ b/src/core/memory.cpp
@@ -195,7 +195,7 @@ int MemoryManager::MapFile(void** out_addr, VAddr virtual_addr, size_t size, Mem
     }
 
     // Map the file.
-    impl.MapFile(mapped_addr, size, offset, fd);
+    impl.MapFile(mapped_addr, size, offset, std::bit_cast<u32>(prot), fd);
 
     // Add virtual memory area
     auto& new_vma = AddMapping(mapped_addr, size_aligned);