mark_reg_graph_node
mark_reg_graph_node(callee->regs, BPF_REG_1, &field->graph_root);
mark_reg_graph_node(callee->regs, BPF_REG_2, &field->graph_root);
mark_reg_graph_node(regs, BPF_REG_0, &field->graph_root);
mark_reg_graph_node(regs, BPF_REG_0, &field->graph_root);