syscalls: fix waitpid's behaviour

src/sys/syscalls/waitpid.c

@@ -37,13 +37,20 @@ syscallret syscall_waitpid(pid_t pid, int *status, int options){
 
 	proc_t* proc = arch_getcls()->thread->proc;
 
-	event_wait(&proc->childevent, true);
+	bool loop = true;
+
+
+	proc_t* child;
+	proc_t* sibling;
+
+	while(1){
+		
+		child = proc->child;
+		sibling = NULL;
 
 		// now find the child
 		
 		spinlock_acquire(&proc->lock);
-	proc_t* child = proc->child;
-	proc_t* sibling = NULL;
 			
 		while(child){
 			if(pid > 0 && child->pid != pid)
@@ -59,6 +66,19 @@ syscallret syscall_waitpid(pid_t pid, int *status, int options){
 
 		}
 
+		spinlock_release(&proc->lock);
+
+		if(loop){
+			event_wait(&proc->childevent, true);
+			loop = false;
+			continue;
+		}
+		else break;
+		
+	}
+
+
+		
 	if(!child){
 		spinlock_release(&proc->lock);
 		retv.errno = ECHILD;
@@ -71,10 +91,17 @@ syscallret syscall_waitpid(pid_t pid, int *status, int options){
 		spinlock_release(&sibling->lock);
 	}
 
-	spinlock_release(&proc->lock);
-
 	*status = child->status; // XXX safer way of doing this
 	
+	// the pointer to the last remaining thread is is proc->threads
+
+	thread_t* thread = child->threads;
+
+	// TODO free ctx
+	
+	free(thread->regs);
+	free(thread->kernelstackbase);
+	free(thread);	
 	free(child);
 
 	retv.ret = child->pid;