diff options
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/signal.c | 22 | ||||
-rw-r--r-- | kernel/task_work.c | 30 |
2 files changed, 1 insertions, 51 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index c37170655171..5736c55aaa1a 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2555,14 +2555,12 @@ bool get_signal(struct ksignal *ksig) * that the arch handlers don't all have to do it. If we get here * without TIF_SIGPENDING, just exit after running signal work. */ -#ifdef TIF_NOTIFY_SIGNAL if (!IS_ENABLED(CONFIG_GENERIC_ENTRY)) { if (test_thread_flag(TIF_NOTIFY_SIGNAL)) tracehook_notify_signal(); if (!task_sigpending(current)) return false; } -#endif if (unlikely(uprobe_deny_signal())) return false; @@ -2576,26 +2574,6 @@ 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 diff --git a/kernel/task_work.c b/kernel/task_work.c index 15b087286bea..9cde961875c0 100644 --- a/kernel/task_work.c +++ b/kernel/task_work.c @@ -5,34 +5,6 @@ static struct callback_head work_exited; /* all we need is ->next == NULL */ -/* - * TWA_SIGNAL signaling - use TIF_NOTIFY_SIGNAL, if available, as it's faster - * than TIF_SIGPENDING as there's no dependency on ->sighand. The latter is - * shared for threads, and can cause contention on sighand->lock. Even for - * the non-threaded case TIF_NOTIFY_SIGNAL is more efficient, as no locking - * or IRQ disabling is involved for notification (or running) purposes. - */ -static void task_work_notify_signal(struct task_struct *task) -{ -#if defined(TIF_NOTIFY_SIGNAL) - set_notify_signal(task); -#else - unsigned long flags; - - /* - * Only grab the sighand lock if we don't already have some - * task_work pending. This pairs with the smp_store_mb() - * in get_signal(), see comment there. - */ - if (!(READ_ONCE(task->jobctl) & JOBCTL_TASK_WORK) && - lock_task_sighand(task, &flags)) { - task->jobctl |= JOBCTL_TASK_WORK; - signal_wake_up(task, 0); - unlock_task_sighand(task, &flags); - } -#endif -} - /** * task_work_add - ask the @task to execute @work->func() * @task: the task which should run the callback @@ -76,7 +48,7 @@ int task_work_add(struct task_struct *task, struct callback_head *work, set_notify_resume(task); break; case TWA_SIGNAL: - task_work_notify_signal(task); + set_notify_signal(task); break; default: WARN_ON_ONCE(1); |