From bd1290706a650f6c059c54024fa7d63ba528bfe5 Mon Sep 17 00:00:00 2001
From: Bananymous <oskari.alaranta@bananymous.com>
Date: Mon, 3 Jun 2024 03:41:00 +0300
Subject: [PATCH] Kernel: Implement SharedMemoryObject cloning

---
 kernel/include/kernel/Memory/SharedMemoryObject.h | 3 ++-
 kernel/kernel/Memory/SharedMemoryObject.cpp       | 7 +++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/kernel/include/kernel/Memory/SharedMemoryObject.h b/kernel/include/kernel/Memory/SharedMemoryObject.h
index 94e15eff..94f82b54 100644
--- a/kernel/include/kernel/Memory/SharedMemoryObject.h
+++ b/kernel/include/kernel/Memory/SharedMemoryObject.h
@@ -32,6 +32,7 @@ namespace Kernel
 		{
 			~Object();
 
+			Key key;
 			size_t size;
 			PageTable::flags_t flags;
 			BAN::Vector<paddr_t> paddrs;
@@ -54,7 +55,7 @@ namespace Kernel
 	public:
 		static BAN::ErrorOr<BAN::UniqPtr<SharedMemoryObject>> create(BAN::RefPtr<SharedMemoryObjectManager::Object>, PageTable&, AddressRange);
 
-		virtual BAN::ErrorOr<BAN::UniqPtr<MemoryRegion>> clone(PageTable& new_page_table) override { return BAN::Error::from_errno(ENOTSUP); }
+		virtual BAN::ErrorOr<BAN::UniqPtr<MemoryRegion>> clone(PageTable& new_page_table) override;
 		virtual BAN::ErrorOr<void> msync(vaddr_t, size_t, int) override { return {}; }
 
 	protected:
diff --git a/kernel/kernel/Memory/SharedMemoryObject.cpp b/kernel/kernel/Memory/SharedMemoryObject.cpp
index 1a8425fc..e6bb7285 100644
--- a/kernel/kernel/Memory/SharedMemoryObject.cpp
+++ b/kernel/kernel/Memory/SharedMemoryObject.cpp
@@ -45,6 +45,7 @@ namespace Kernel
 		Key key = generate_key();
 		while (m_objects.contains(key))
 			key = generate_key();
+		object->key = key;
 
 		TRY(m_objects.insert(key, object));
 		return key;
@@ -80,6 +81,12 @@ namespace Kernel
 		return BAN::move(smo);
 	}
 
+	BAN::ErrorOr<BAN::UniqPtr<MemoryRegion>> SharedMemoryObject::clone(PageTable& new_page_table)
+	{
+		auto region = TRY(SharedMemoryObjectManager::get().map_object(m_object->key, new_page_table, { .start = vaddr(), .end = vaddr() + size() }));
+		return BAN::UniqPtr<MemoryRegion>(BAN::move(region));
+	}
+
 	BAN::ErrorOr<bool> SharedMemoryObject::allocate_page_containing_impl(vaddr_t address)
 	{
 		ASSERT(contains(address));