Kernel: Make sure MSB is not set on SMO keys

I forgot to change this when changing the lock type. 32 bit boots again
fine :D

kernel/arch/i686/PageTable.cpp

@@ -178,7 +178,7 @@ namespace Kernel
 		ASSERT(s_kernel);
 		ASSERT(paddr);
 
-		SpinLockGuard _(s_fast_page_lock);
+		ASSERT(s_fast_page_lock.current_processor_has_lock());
 
 		constexpr uint64_t pdpte = (fast_page() >> 30) & 0x1FF;
 		constexpr uint64_t pde   = (fast_page() >> 21) & 0x1FF;
@@ -198,7 +198,7 @@ namespace Kernel
 	{
 		ASSERT(s_kernel);
 
-		SpinLockGuard _(s_fast_page_lock);
+		ASSERT(s_fast_page_lock.current_processor_has_lock());
 
 		constexpr uint64_t pdpte = (fast_page() >> 30) & 0x1FF;
 		constexpr uint64_t pde   = (fast_page() >> 21) & 0x1FF;

kernel/include/kernel/Memory/SharedMemoryObject.h

@@ -14,7 +14,7 @@ namespace Kernel
 	class SharedMemoryObjectManager
 	{
 	public:
-		using Key = uint32_t;
+		using Key = size_t;
 
 	public:
 		static BAN::ErrorOr<void> initialize();

kernel/include/kernel/Random.h

@@ -11,14 +11,12 @@ namespace Kernel
 		static void initialize();
 		static uint32_t get_u32();
 		static uint64_t get_u64();
-		template<typename T>
+		template<BAN::unsigned_integral T> requires (sizeof(T) == 4)
-		static T get();
+		static T get() { return Random::get_u32(); }
+		template<BAN::unsigned_integral T> requires (sizeof(T) == 8)
+		static T get() { return Random::get_u64(); }
 	};
 
-	template<>
-	inline uint32_t Random::get<uint32_t>() { return Random::get_u32(); }
 
-	template<>
-	inline uint64_t Random::get<uint64_t>() { return Random::get_u64(); }
 
 }

kernel/kernel/Memory/SharedMemoryObject.cpp

@@ -32,9 +32,12 @@ namespace Kernel
 
 		LockGuard _(m_mutex);
 
-		Key key = Random::get<Key>();
+		// NOTE: don't set the top bit so cast to signed is not negative
+		auto generate_key = []() { return Random::get<Key>() & (~(Key)0 >> 1); };
+
+		Key key = generate_key();
 		while (m_objects.contains(key))
-			key = Random::get<Key>();
+			key = generate_key();
 
 		TRY(m_objects.insert(key, object));
 		return key;