Kernel: Allocators are now stored in UniqPtr

This allows proper memory management, we had some memory leak

kernel/include/kernel/Memory/FixedWidthAllocator.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <BAN/UniqPtr.h>
 #include <kernel/Memory/Heap.h>
 #include <kernel/Memory/PageTable.h>
 
@@ -12,10 +13,10 @@ namespace Kernel
 		BAN_NON_MOVABLE(FixedWidthAllocator);
 
 	public:
-		FixedWidthAllocator(PageTable&, uint32_t);
+		static BAN::ErrorOr<BAN::UniqPtr<FixedWidthAllocator>> create(PageTable&, uint32_t);
 		~FixedWidthAllocator();
 
-		BAN::ErrorOr<FixedWidthAllocator*> clone(PageTable&);
+		BAN::ErrorOr<BAN::UniqPtr<FixedWidthAllocator>> clone(PageTable&);
 
 		vaddr_t allocate();
 		bool deallocate(vaddr_t);
@@ -26,6 +27,7 @@ namespace Kernel
 		uint32_t max_allocations() const;
 
 	private:
+		FixedWidthAllocator(PageTable&, uint32_t);
 		bool allocate_page_if_needed(vaddr_t, uint8_t flags);
 
 		struct node

kernel/include/kernel/Memory/GeneralAllocator.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <BAN/LinkedList.h>
+#include <BAN/UniqPtr.h>
 #include <kernel/Memory/Heap.h>
 #include <kernel/Memory/PageTable.h>
 
@@ -13,13 +14,16 @@ namespace Kernel
 		BAN_NON_MOVABLE(GeneralAllocator);
 
 	public:
-		GeneralAllocator(PageTable&);
+		static BAN::ErrorOr<BAN::UniqPtr<GeneralAllocator>> create(PageTable&);
 		~GeneralAllocator();
 
+		BAN::ErrorOr<BAN::UniqPtr<GeneralAllocator>> clone(PageTable&);
+
 		vaddr_t allocate(size_t);
 		bool deallocate(vaddr_t);
 
-		BAN::ErrorOr<GeneralAllocator*> clone(PageTable&);
+	private:
+		GeneralAllocator(PageTable&);
 
 	private:
 		struct Allocation

kernel/include/kernel/Process.h

@@ -114,12 +114,12 @@ namespace Kernel
 		BAN::String m_working_directory;
 		BAN::Vector<Thread*> m_threads;
 
-		BAN::Vector<FixedWidthAllocator*> m_fixed_width_allocators;
+		BAN::Vector<BAN::UniqPtr<FixedWidthAllocator>> m_fixed_width_allocators;
-		GeneralAllocator* m_general_allocator;
+		BAN::UniqPtr<GeneralAllocator> m_general_allocator;
 
 		userspace_entry_t m_userspace_entry;
 
-		PageTable* m_page_table { nullptr };
+		BAN::UniqPtr<PageTable> m_page_table;
 		TTY* m_tty { nullptr };
 	};
 

kernel/kernel/Memory/FixedWidthAllocator.cpp

@@ -3,6 +3,14 @@
 namespace Kernel
 {
 
+	BAN::ErrorOr<BAN::UniqPtr<FixedWidthAllocator>> FixedWidthAllocator::create(PageTable& page_table, uint32_t allocation_size)
+	{
+		auto* allocator = new FixedWidthAllocator(page_table, allocation_size);
+		if (allocator == nullptr)
+			return BAN::Error::from_errno(ENOMEM);
+		return BAN::UniqPtr<FixedWidthAllocator>::adopt(allocator);
+	}
+
 	FixedWidthAllocator::FixedWidthAllocator(PageTable& page_table, uint32_t allocation_size)
 		: m_page_table(page_table)
 		, m_allocation_size(BAN::Math::max(allocation_size, m_min_allocation_size))
@@ -222,14 +230,11 @@ namespace Kernel
 		ASSERT_NOT_REACHED();
 	}
 
-	BAN::ErrorOr<FixedWidthAllocator*> FixedWidthAllocator::clone(PageTable& new_page_table)
+	BAN::ErrorOr<BAN::UniqPtr<FixedWidthAllocator>> FixedWidthAllocator::clone(PageTable& new_page_table)
 	{
-		FixedWidthAllocator* allocator = new FixedWidthAllocator(new_page_table, allocation_size());
+		auto allocator = TRY(FixedWidthAllocator::create(new_page_table, allocation_size()));
-		if (allocator == nullptr)
-			return BAN::Error::from_errno(ENOMEM);
 
 		m_page_table.lock();
-
 		ASSERT(m_page_table.is_page_free(0));
 
 		for (node* node = m_used_list; node; node = node->next)

kernel/kernel/Memory/GeneralAllocator.cpp

@@ -1,8 +1,17 @@
 #include <kernel/Memory/GeneralAllocator.h>
+#include <kernel/Memory/PageTableScope.h>
 
 namespace Kernel
 {
 
+	BAN::ErrorOr<BAN::UniqPtr<GeneralAllocator>> GeneralAllocator::create(PageTable& page_table)
+	{
+		auto* allocator = new GeneralAllocator(page_table);
+		if (allocator == nullptr)
+			return BAN::Error::from_errno(ENOMEM);
+		return BAN::UniqPtr<GeneralAllocator>::adopt(allocator);
+	}
+
 	GeneralAllocator::GeneralAllocator(PageTable& page_table)
 		: m_page_table(page_table)
 	{ }
@@ -60,11 +69,9 @@ namespace Kernel
 		return false;
 	}
 
-	BAN::ErrorOr<GeneralAllocator*> GeneralAllocator::clone(PageTable& new_page_table)
+	BAN::ErrorOr<BAN::UniqPtr<GeneralAllocator>> GeneralAllocator::clone(PageTable& new_page_table)
 	{
-		GeneralAllocator* allocator = new GeneralAllocator(new_page_table);
+		auto allocator = TRY(GeneralAllocator::create(new_page_table));
-		if (allocator == nullptr)
-			return BAN::Error::from_errno(ENOMEM);
 
 		m_page_table.lock();
 

kernel/kernel/Process.cpp

@@ -56,7 +56,7 @@ namespace Kernel
 
 		auto* process = create_process();
 		MUST(process->m_working_directory.push_back('/'));
-		process->m_page_table = MUST(PageTable::create_userspace());
+		process->m_page_table = BAN::UniqPtr<PageTable>::adopt(MUST(PageTable::create_userspace()));
 
 		process->load_elf(*elf);
 
@@ -91,13 +91,9 @@ namespace Kernel
 	{
 		ASSERT(m_threads.empty());
 		ASSERT(m_fixed_width_allocators.empty());
-		ASSERT(m_general_allocator == nullptr);
+		ASSERT(!m_general_allocator);
 		ASSERT(m_mapped_ranges.empty());
-		if (m_page_table)
+		ASSERT(&PageTable::current() != m_page_table.ptr());
-		{
-			PageTable::kernel().load();
-			delete m_page_table;
-		}
 
 		dprintln("process {} exit", pid());
 	}
@@ -133,11 +129,7 @@ namespace Kernel
 
 		// NOTE: We must clear allocators while the page table is still alive
 		m_fixed_width_allocators.clear();
-		if (m_general_allocator)
+		m_general_allocator.clear();
-		{
-			delete m_general_allocator;
-			m_general_allocator = nullptr;
-		}
 
 		s_process_lock.lock();
 		for (size_t i = 0; i < s_processes.size(); i++)
@@ -163,7 +155,7 @@ namespace Kernel
 	{
 		Process* forked = create_process();
 
-		forked->m_page_table = MUST(PageTable::create_userspace());
+		forked->m_page_table = BAN::UniqPtr<PageTable>::adopt(MUST(PageTable::create_userspace()));
 
 		LockGuard _(m_lock);
 		forked->m_tty = m_tty;
@@ -180,7 +172,8 @@ namespace Kernel
 		ASSERT(m_threads.front() == &Thread::current());
 
 		for (auto& allocator : m_fixed_width_allocators)
-			MUST(forked->m_fixed_width_allocators.push_back(MUST(allocator->clone(forked->page_table()))));
+			if (allocator->allocations() > 0)
+				MUST(forked->m_fixed_width_allocators.push_back(MUST(allocator->clone(forked->page_table()))));
 
 		if (m_general_allocator)
 			forked->m_general_allocator = MUST(m_general_allocator->clone(forked->page_table()));
@@ -554,21 +547,20 @@ namespace Kernel
 
 			bool needs_new_allocator { true };
 
-			for (auto* allocator : m_fixed_width_allocators)
+			for (auto& allocator : m_fixed_width_allocators)
 			{
 				if (allocator->allocation_size() == allocation_size && allocator->allocations() < allocator->max_allocations())
 				{
 					address = allocator->allocate();
 					needs_new_allocator = false;
+					break;
 				}
 			}
 
 			if (needs_new_allocator)
 			{
-				auto* allocator = new FixedWidthAllocator(page_table(), allocation_size);
+				auto allocator = TRY(FixedWidthAllocator::create(page_table(), allocation_size));
-				if (allocator == nullptr)
+				TRY(m_fixed_width_allocators.push_back(BAN::move(allocator)));
-					return BAN::Error::from_errno(ENOMEM);
-				TRY(m_fixed_width_allocators.push_back(allocator));
 				address = m_fixed_width_allocators.back()->allocate();
 			}
 		}
@@ -577,11 +569,7 @@ namespace Kernel
 			LockGuard _(m_lock);
 
 			if (!m_general_allocator)
-			{
+				m_general_allocator = TRY(GeneralAllocator::create(page_table()));
-				m_general_allocator = new GeneralAllocator(page_table());
-				if (m_general_allocator == nullptr)
-					return BAN::Error::from_errno(ENOMEM);
-			}
 
 			address = m_general_allocator->allocate(bytes);
 		}
@@ -597,7 +585,7 @@ namespace Kernel
 
 		for (size_t i = 0; i < m_fixed_width_allocators.size(); i++)
 		{
-			auto* allocator = m_fixed_width_allocators[i];
+			auto& allocator = m_fixed_width_allocators[i];
 			if (allocator->deallocate((vaddr_t)ptr))
 			{
 				// TODO: This might be too much. Maybe we should only