* Return the first synchronous signal in the queue.
*/
list_for_each_entry(q, &pending->list, list) {
- /* Synchronous signals have a postive si_code */
+ /* Synchronous signals have a positive si_code */
if ((q->info.si_code > SI_USER) &&
(sigmask(q->info.si_signo) & SYNCHRONOUS_MASK)) {
sync = q;
relock:
spin_lock_irq(&sighand->siglock);
- current->jobctl &= ~JOBCTL_TASK_WORK;
+ /*
+ * Make sure we can safely read ->jobctl() in task_work add. As Oleg
+ * states:
+ *
+ * It pairs with mb (implied by cmpxchg) before READ_ONCE. So we
+ * roughly have
+ *
+ * task_work_add: get_signal:
+ * STORE(task->task_works, new_work); STORE(task->jobctl);
+ * mb(); mb();
+ * LOAD(task->jobctl); LOAD(task->task_works);
+ *
+ * and we can rely on STORE-MB-LOAD [ in task_work_add].
+ */
+ smp_store_mb(current->jobctl, current->jobctl & ~JOBCTL_TASK_WORK);
if (unlikely(current->task_works)) {
spin_unlock_irq(&sighand->siglock);
task_work_run();