Kernel: Fix most of mutex + block race conditions

All block functions now take an optional mutex parameter that is
atomically unlocked instead of having the user unlock it before hand.
This prevents a ton of race conditions everywhere in the code!

kernel/include/kernel/Memory/MemoryRegion.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <BAN/UniqPtr.h>
+#include <kernel/Lock/Mutex.h>
 #include <kernel/Memory/PageTable.h>
 #include <kernel/Memory/Types.h>
 #include <kernel/ThreadBlocker.h>
@@ -41,9 +42,9 @@ namespace Kernel
 		size_t virtual_page_count() const { return BAN::Math::div_round_up<size_t>(m_size, PAGE_SIZE); }
 		size_t physical_page_count() const { return m_physical_page_count; }
 
-		void pin() { m_pinned_count++; }
-		void unpin() { if (--m_pinned_count == 0) m_pinned_blocker.unblock(); }
-		void wait_not_pinned() { while (m_pinned_count) m_pinned_blocker.block_with_timeout_ms(100); }
+		void pin();
+		void unpin();
+		void wait_not_pinned();
 
 		virtual BAN::ErrorOr<void> msync(vaddr_t, size_t, int) = 0;
 
@@ -68,6 +69,7 @@ namespace Kernel
 		vaddr_t m_vaddr { 0 };
 		size_t m_physical_page_count { 0 };
 
+		Mutex m_pinned_mutex;
 		BAN::Atomic<size_t> m_pinned_count { 0 };
 		ThreadBlocker m_pinned_blocker;
 	};