tasking: Check for null pointer first

kernel_thread.cpp

@@ -111,7 +111,10 @@ void KernelMainThread()
 	initProc = TaskManager->GetProcessByID(tid);
 	initThread = TaskManager->GetThreadByID(tid, initProc);
 	TaskManager->WaitForThread(initThread);
-	ExitCode = initThread->GetExitCode();
+	if (initThread)
+		ExitCode = initThread->GetExitCode();
+	else
+		ExitCode = 0xEBAD;
 Exit:
 	KPrint("\x1b[31mUserspace process exited with code %d (%#x)",
 		   ExitCode, ExitCode < 0 ? -ExitCode : ExitCode);

tasking/scheduler/custom.cpp

@@ -157,6 +157,9 @@ namespace Tasking::Scheduler
 
 	TCB *Custom::GetThreadByID(TID ID, PCB *Parent)
 	{
+		if (unlikely(Parent == nullptr))
+			return nullptr;
+
 		foreach (auto t in Parent->Threads)
 		{
 			if (t->ID == ID)
@@ -544,6 +547,7 @@ namespace Tasking::Scheduler
 		{
 			if (pcb->State.load() == TaskState::Terminated)
 			{
+				debug("Found terminated process %s(%d)", pcb->Name, pcb->ID);
 				delete pcb;
 				continue;
 			}

tasking/task.cpp

@@ -105,6 +105,9 @@ namespace Tasking
 
 	void Task::WaitForProcess(PCB *pcb)
 	{
+		if (pcb == nullptr)
+			return;
+
 		if (pcb->State == TaskState::UnknownStatus)
 			return;
 
@@ -119,6 +122,9 @@ namespace Tasking
 
 	void Task::WaitForThread(TCB *tcb)
 	{
+		if (tcb == nullptr)
+			return;
+
 		if (tcb->State == TaskState::UnknownStatus)
 			return;
 
@@ -133,6 +139,9 @@ namespace Tasking
 
 	void Task::WaitForProcessStatus(PCB *pcb, TaskState status)
 	{
+		if (pcb == nullptr)
+			return;
+
 		if (pcb->State == TaskState::UnknownStatus)
 			return;
 
@@ -145,6 +154,9 @@ namespace Tasking
 
 	void Task::WaitForThreadStatus(TCB *tcb, TaskState status)
 	{
+		if (tcb == nullptr)
+			return;
+
 		if (tcb->State == TaskState::UnknownStatus)
 			return;