Better memory management

src/driver/hypervisor.cpp

@@ -4,6 +4,7 @@
 #include "exception.hpp"
 #include "logging.hpp"
 #include "finally.hpp"
+#include "memory.hpp"
 #include "thread.hpp"
 
 #define IA32_FEATURE_CONTROL_MSR 0x3A
@@ -34,34 +35,6 @@ namespace
 	{
 		return is_vmx_supported() && is_vmx_available();
 	}
-
-	_IRQL_requires_max_(DISPATCH_LEVEL)
-
-	void free_aligned_memory(void* memory)
-	{
-		MmFreeContiguousMemory(memory);
-	}
-
-	_Must_inspect_result_
-	_IRQL_requires_max_(DISPATCH_LEVEL)
-
-	void* allocate_aligned_memory(const size_t size)
-	{
-		PHYSICAL_ADDRESS lowest{}, highest{};
-		lowest.QuadPart = 0;
-		highest.QuadPart = lowest.QuadPart - 1;
-
-#if (NTDDI_VERSION >= NTDDI_VISTA)
-		return MmAllocateContiguousNodeMemory(size,
-		                                      lowest,
-		                                      highest,
-		                                      lowest,
-		                                      PAGE_READWRITE,
-		                                      KeGetCurrentNodeNumber());
-#else
-		return MmAllocateContiguousMemory(size, highest);
-#endif
-	}
 }
 
 hypervisor::hypervisor()
@@ -125,23 +98,27 @@ void hypervisor::disable_core()
 
 void hypervisor::allocate_vm_states()
 {
+	if (this->vm_states_)
+	{
+		throw std::runtime_error("VM states are still in use");
+	}
+
 	const auto core_count = thread::get_processor_count();
 	const auto allocation_size = sizeof(vmx::vm_state) * core_count;
 
-	this->vm_states_ = static_cast<vmx::vm_state*>(allocate_aligned_memory(allocation_size));
+	this->vm_states_ = static_cast<vmx::vm_state*>(memory::allocate_aligned_memory(allocation_size));
-	if(!this->vm_states_)
+	if (!this->vm_states_)
 	{
-		throw std::runtime_error("Failed to allocate vm states");
+		throw std::runtime_error("Failed to allocate VM states");
 	}
+
+	RtlSecureZeroMemory(this->vm_states_, allocation_size);
 }
 
 void hypervisor::free_vm_states()
 {
-	if(this->vm_states_)
+	memory::free_aligned_memory(this->vm_states_);
-	{
+	this->vm_states_ = nullptr;
-		free_aligned_memory(this->vm_states_);
-		this->vm_states_ = nullptr;
-	}
 }
 
 vmx::vm_state* hypervisor::get_current_vm_state() const

src/driver/memory.cpp

@@ -0,0 +1,74 @@
+#include "std_include.hpp"
+#include "memory.hpp"
+
+namespace memory
+{
+	namespace
+	{
+		void* allocate_aligned_memory_internal(const size_t size)
+		{
+			PHYSICAL_ADDRESS lowest{}, highest{};
+			lowest.QuadPart = 0;
+			highest.QuadPart = lowest.QuadPart - 1;
+
+#if (NTDDI_VERSION >= NTDDI_VISTA)
+			return MmAllocateContiguousNodeMemory(size,
+			                                      lowest,
+			                                      highest,
+			                                      lowest,
+			                                      PAGE_READWRITE,
+			                                      KeGetCurrentNodeNumber());
+#else
+		return MmAllocateContiguousMemory(size, highest);
+#endif
+		}
+	}
+
+	_IRQL_requires_max_(DISPATCH_LEVEL)
+
+	void free_aligned_memory(void* memory)
+	{
+		if (memory)
+		{
+			MmFreeContiguousMemory(memory);
+		}
+	}
+
+	_Must_inspect_result_
+	_IRQL_requires_max_(DISPATCH_LEVEL)
+
+	void* allocate_aligned_memory(const size_t size)
+	{
+		void* memory = allocate_aligned_memory_internal(size);
+		if (memory)
+		{
+			RtlSecureZeroMemory(memory, size);
+		}
+
+		return memory;
+	}
+
+	_Must_inspect_result_
+	_IRQL_requires_max_(DISPATCH_LEVEL)
+
+	void* allocate_non_paged_memory(const size_t size)
+	{
+		void* memory = ExAllocatePoolWithTag(NonPagedPool, size, 'MOMO');
+		if (memory)
+		{
+			RtlSecureZeroMemory(memory, size);
+		}
+
+		return memory;
+	}
+
+	_IRQL_requires_max_(DISPATCH_LEVEL)
+
+	void free_non_paged_memory(void* memory)
+	{
+		if (memory)
+		{
+			ExFreePool(memory);
+		}
+	}
+}

src/driver/memory.hpp

@@ -0,0 +1,18 @@
+#pragma once
+
+namespace memory
+{
+	_IRQL_requires_max_(DISPATCH_LEVEL)
+	void free_aligned_memory(void* memory);
+
+	_Must_inspect_result_
+	_IRQL_requires_max_(DISPATCH_LEVEL)
+	void* allocate_aligned_memory(size_t size);
+
+	_Must_inspect_result_
+	_IRQL_requires_max_(DISPATCH_LEVEL)
+	void* allocate_non_paged_memory(size_t size);
+
+	_IRQL_requires_max_(DISPATCH_LEVEL)
+	void free_non_paged_memory(void* memory);
+}

src/driver/new.cpp

@@ -1,12 +1,13 @@
 #include "std_include.hpp"
 #include "new.hpp"
 #include "exception.hpp"
+#include "memory.hpp"
 
 namespace
 {
-	void* perform_allocation(const size_t size, const POOL_TYPE pool, const unsigned long tag)
+	void* perform_checked_non_paged_allocation(const size_t size)
 	{
-		auto* memory = ExAllocatePoolWithTag(pool, size, tag);
+		auto* memory = memory::allocate_non_paged_memory(size);
 		if (!memory)
 		{
 			throw std::runtime_error("Memory allocation failed");
@@ -16,24 +17,14 @@ namespace
 	}
 }
 
-void* operator new(const size_t size, const POOL_TYPE pool, const unsigned long tag)
-{
-	return perform_allocation(size, pool, tag);
-}
-
-void* operator new[](const size_t size, const POOL_TYPE pool, const unsigned long tag)
-{
-	return perform_allocation(size, pool, tag);
-}
-
 void* operator new(const size_t size)
 {
-	return operator new(size, NonPagedPool);
+	return perform_checked_non_paged_allocation(size);
 }
 
 void* operator new[](const size_t size)
 {
-	return operator new[](size, NonPagedPool);
+	return perform_checked_non_paged_allocation(size);
 }
 
 //	Placement new
@@ -44,22 +35,22 @@ void* operator new(size_t, void* where)
 
 void operator delete(void* ptr, size_t)
 {
-	ExFreePool(ptr);
+	memory::free_non_paged_memory(ptr);
 }
 
 void operator delete(void* ptr)
 {
-	ExFreePool(ptr);
+	memory::free_non_paged_memory(ptr);
 }
 
 void operator delete[](void* ptr, size_t)
 {
-	ExFreePool(ptr);
+	memory::free_non_paged_memory(ptr);
 }
 
 void operator delete[](void* ptr)
 {
-	ExFreePool(ptr);
+	memory::free_non_paged_memory(ptr);
 }
 
 extern "C" void __std_terminate()

src/driver/new.hpp

@@ -1,7 +1,5 @@
 #pragma once
 
-void* operator new(size_t size, POOL_TYPE pool, unsigned long tag = 'momo');
-void* operator new[](size_t size, POOL_TYPE pool, unsigned long tag = 'momo');
 void* operator new(size_t size);
 void* operator new[](size_t size);