diff options
Diffstat (limited to 'kernel/signal.c')
| -rw-r--r-- | kernel/signal.c | 26 |
1 files changed, 22 insertions, 4 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index 5ca48cc5da76..42b67d2cea37 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -719,7 +719,7 @@ static int dequeue_synchronous_signal(kernel_siginfo_t *info) * 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; @@ -2529,9 +2529,6 @@ bool get_signal(struct ksignal *ksig) struct signal_struct *signal = current->signal; int signr; - if (unlikely(current->task_works)) - task_work_run(); - if (unlikely(uprobe_deny_signal())) return false; @@ -2545,6 +2542,27 @@ bool get_signal(struct ksignal *ksig) relock: spin_lock_irq(&sighand->siglock); /* + * 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(); + goto relock; + } + + /* * Every stopped thread goes here after wakeup. Check to see if * we should notify the parent, prepare_signal(SIGCONT) encodes * the CLD_ si_code into SIGNAL_CLD_MASK bits. |