diff options
Diffstat (limited to 'kernel/signal.c')
| -rw-r--r-- | kernel/signal.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index 6f16f7c5d375..a38b3edc6851 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -851,7 +851,7 @@ static int check_kill_permission(int sig, struct kernel_siginfo *info, */ if (!sid || sid == task_session(current)) break; - /* fall through */ + fallthrough; default: return -EPERM; } @@ -2541,7 +2541,21 @@ bool get_signal(struct ksignal *ksig) 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(); |