Kernel: Fix shm object freeing and track lpid

I was deleting based on the key instead of the id which of course does
not work :D

kernel/include/kernel/Memory/SharedMemoryObject.h

@@ -27,8 +27,9 @@ namespace Kernel
 	private:
 		struct Object : public BAN::RefCounted<Object>
 		{
-			Object(key_t key, shmid_ds info)
+			Object(key_t key, int id, shmid_ds info)
 				: key(key)
+				, id(id)
 				, info(info)
 			{ }
 			~Object();
@@ -36,6 +37,7 @@ namespace Kernel
 			bool can_current_process_access(int flags) const;
 
 			const key_t key;
+			const int id;
 			shmid_ds info;
 
 			Mutex mutex;

kernel/kernel/Memory/SharedMemoryObject.cpp

@@ -93,7 +93,15 @@ namespace Kernel
 		const pid_t pid = process.pid();
 		const mode_t mode = shmflg & 0777;
 
-		auto object = TRY(BAN::RefPtr<Object>::create(key, shmid_ds {
+		const int shmid = ({
+			int id;
+			do {
+				id = Random::get<unsigned>() & BAN::numeric_limits<int>::max();
+			} while (m_ids.contains(shmid));
+			id;
+		});
+
+		auto object = TRY(BAN::RefPtr<Object>::create(key, shmid, shmid_ds {
 				.shm_perm = {
 					.uid = uid,
 					.gid = gid,
@@ -111,12 +119,6 @@ namespace Kernel
 		}));
 		TRY(object->paddrs.resize(BAN::Math::div_round_up(size, PAGE_SIZE), 0));
 
-		auto generate_id = []() { return Random::get<unsigned>() & BAN::numeric_limits<int>::max(); };
-
-		int shmid = generate_id();
-		while (m_ids.contains(shmid))
-			shmid = generate_id();
-
 		if (key != IPC_PRIVATE)
 			TRY(m_ids.insert(key, shmid));
 
@@ -222,14 +224,16 @@ namespace Kernel
 		LockGuard _(m_object->mutex);
 		m_object->info.shm_nattch++;
 		m_object->info.shm_atime = SystemTimer::get().real_time().tv_sec;
+		m_object->info.shm_lpid = Process::current().pid();
 	}
 
 	SharedMemoryObject::~SharedMemoryObject()
 	{
 		LockGuard _(m_object->mutex);
 		if (--m_object->info.shm_nattch == 0 && m_object->marked_for_deletion)
-			SharedMemoryObjectManager::get().m_objects.remove(m_object->key);
+			SharedMemoryObjectManager::get().m_objects.remove(m_object->id);
 		m_object->info.shm_dtime = SystemTimer::get().real_time().tv_sec;
+		m_object->info.shm_lpid = Process::current().pid();
 	}
 
 	BAN::ErrorOr<BAN::UniqPtr<MemoryRegion>> SharedMemoryObject::clone(PageTable& new_page_table)