Don't leak FDT

src/arch/x86/paging.cpp

@@ -161,8 +161,13 @@ int AddressSpace::unmap(void *virt) {
     return 1;
 }
 FDT *AddressSpace::getFdt() {
-    if (!_fdt) _fdt = new FDT();
-    return _fdt;
+    if (_fdt.get() == nullptr) {
+        LockGuard l(_fdtLock);
+        if (_fdt.get() == nullptr) {
+            _fdt = UniquePtr(new FDT());
+        }
+    }
+    return _fdt.get();
 }
 
 static volatile struct limine_kernel_address_request kernel_address_request = {

src/arch/x86/paging.hpp

@@ -9,6 +9,7 @@
 #include <stdint.h>
 
 #include "PointersCollection.hpp"
+#include "mutex.hpp"
 
 #define PAGE_SIZE   4096
 
@@ -44,9 +45,10 @@ public:
 
 private:
     // Pointer to PML4 in HHDM
-    uint64_t *PML4;
+    uint64_t      *PML4;
 
-    FDT      *_fdt = nullptr;
+    UniquePtr<FDT> _fdt;
+    Mutex          _fdtLock;
 };
 
 extern AddressSpace *KERN_AddressSpace;