+ * user- or fsys-mode, hence we disable interrupts early on.
+ *
+ * p6 controls whether current_thread_info()->flags needs to be check for
+ * extra work. We always check for extra work when returning to user-level.
+ * With CONFIG_PREEMPT, we also check for extra work when the preempt_count
+ * is 0. After extra work processing has been completed, execution
+ * resumes at .work_processed_syscall with p6 set to 1 if the extra-work-check
+ * needs to be redone.