From 7a83b74d3e372b3062025002c651707af1d404d4 Mon Sep 17 00:00:00 2001
From: "Daniel R." <47796739+polybiusproxy@users.noreply.github.com>
Date: Wed, 10 Jul 2024 19:22:11 +0200
Subject: [PATCH] Fix `sceKernelReserveVirtualRange`.

---
 .../libraries/kernel/memory_management.cpp    |  4 +-
 src/core/memory.cpp                           | 50 ++++++++++++++++---
 src/core/memory.h                             |  3 ++
 3 files changed, 48 insertions(+), 9 deletions(-)

diff --git a/src/core/libraries/kernel/memory_management.cpp b/src/core/libraries/kernel/memory_management.cpp
index 61a6ae734..92fde9600 100644
--- a/src/core/libraries/kernel/memory_management.cpp
+++ b/src/core/libraries/kernel/memory_management.cpp
@@ -107,9 +107,9 @@ s32 PS4_SYSV_ABI sceKernelReserveVirtualRange(void** addr, u64 len, int flags, u
     }
 
     auto* memory = Core::Memory::Instance();
+    const VAddr in_addr = reinterpret_cast<VAddr>(*addr);
     const auto map_flags = static_cast<Core::MemoryMapFlags>(flags);
-    memory->MapMemory(addr, 0, len, Core::MemoryProt::NoAccess, map_flags, Core::VMAType::Direct,
-                      "", false, -1, alignment);
+    memory->Reserve(addr, in_addr, len, map_flags, alignment);
 
     return SCE_OK;
 }
diff --git a/src/core/memory.cpp b/src/core/memory.cpp
index 7eb9a0fa7..a1af228b2 100644
--- a/src/core/memory.cpp
+++ b/src/core/memory.cpp
@@ -83,6 +83,25 @@ void MemoryManager::Free(PAddr phys_addr, size_t size) {
     MergeAdjacent(dmem_map, dmem_area);
 }
 
+int MemoryManager::Reserve(void** out_addr, VAddr virtual_addr, size_t size, MemoryMapFlags flags,
+                            u64 alignment) {
+    std::scoped_lock lk{mutex};
+
+    virtual_addr = (virtual_addr == 0) ? impl.VirtualBase() : virtual_addr;
+
+    VAddr mapped_addr = alignment > 0 ? Common::AlignUp(virtual_addr, alignment) : virtual_addr;
+
+    // Add virtual memory area
+    auto& new_vma = AddMapping(mapped_addr, size);
+    new_vma.disallow_merge = True(flags & MemoryMapFlags::NoCoalesce);
+    new_vma.prot = MemoryProt::NoAccess;
+    new_vma.name = "";
+    new_vma.type = VMAType::Reserved;
+
+    *out_addr = std::bit_cast<void*>(mapped_addr);
+    return ORBIS_OK;
+}
+
 int MemoryManager::MapMemory(void** out_addr, VAddr virtual_addr, size_t size, MemoryProt prot,
                              MemoryMapFlags flags, VMAType type, std::string_view name,
                              bool is_exec, PAddr phys_addr, u64 alignment) {
@@ -146,18 +165,35 @@ int MemoryManager::MapMemory(void** out_addr, VAddr virtual_addr, size_t size, M
 
 int MemoryManager::MapFile(void** out_addr, VAddr virtual_addr, size_t size, MemoryProt prot,
                            MemoryMapFlags flags, uintptr_t fd, size_t offset) {
-    virtual_addr = impl.VirtualBase();
+    if (virtual_addr == 0) {
+        virtual_addr = impl.VirtualBase();
+    } else {
+        LOG_INFO(Kernel_Vmm, "Virtual addr {:#x} with size {:#x}", virtual_addr, size);
+    }
+    
+    VAddr mapped_addr = 0;
     const size_t size_aligned = Common::AlignUp(size, 16_KB);
 
     // Find first free area to map the file.
-    auto it = FindVMA(virtual_addr);
-    while (it->second.type != VMAType::Free || it->second.size < size_aligned) {
-        it++;
+    if (False(flags & MemoryMapFlags::Fixed)) {
+        auto it = FindVMA(virtual_addr);
+        while (it->second.type != VMAType::Free || it->second.size < size_aligned) {
+            it++;
+        }
+        ASSERT(it != vma_map.end());
+
+        mapped_addr = it->second.base;
+    }
+
+    if (True(flags & MemoryMapFlags::Fixed)) {
+        const auto& vma = FindVMA(virtual_addr)->second;
+        const size_t remaining_size = vma.base + vma.size - virtual_addr;
+        ASSERT_MSG((vma.type == VMAType::Free || vma.type == VMAType::Reserved) && remaining_size >= size);
+
+        mapped_addr = virtual_addr;
     }
-    ASSERT(it != vma_map.end());
 
     // Map the file.
-    const VAddr mapped_addr = it->second.base;
     impl.MapFile(mapped_addr, size, offset, fd);
 
     // Add virtual memory area
@@ -302,7 +338,7 @@ VirtualMemoryArea& MemoryManager::AddMapping(VAddr virtual_addr, size_t size) {
     ASSERT_MSG(vma_handle != vma_map.end(), "Virtual address not in vm_map");
 
     const VirtualMemoryArea& vma = vma_handle->second;
-    ASSERT_MSG(vma.type == VMAType::Free && vma.base <= virtual_addr,
+    ASSERT_MSG((vma.type == VMAType::Free || vma.type == VMAType::Reserved) && vma.base <= virtual_addr,
                "Adding a mapping to already mapped region");
 
     const VAddr start_in_vma = virtual_addr - vma.base;
diff --git a/src/core/memory.h b/src/core/memory.h
index 220fa43ff..d4f1047ba 100644
--- a/src/core/memory.h
+++ b/src/core/memory.h
@@ -137,6 +137,9 @@ public:
 
     void Free(PAddr phys_addr, size_t size);
 
+    int Reserve(void** out_addr, VAddr virtual_addr, size_t size, MemoryMapFlags flags,
+                 u64 alignment = 0);
+
     int MapMemory(void** out_addr, VAddr virtual_addr, size_t size, MemoryProt prot,
                   MemoryMapFlags flags, VMAType type, std::string_view name = "",
                   bool is_exec = false, PAddr phys_addr = -1, u64 alignment = 0);