diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/events/uprobes.c | 2 | ||||
| -rw-r--r-- | kernel/irq/manage.c | 2 | ||||
| -rw-r--r-- | kernel/sched/fair.c | 2 | ||||
| -rw-r--r-- | kernel/task_work.c | 30 |
4 files changed, 23 insertions, 13 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 0e18aaf23a7b..00b0358739ab 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -1823,7 +1823,7 @@ void uprobe_copy_process(struct task_struct *t, unsigned long flags) t->utask->dup_xol_addr = area->vaddr; init_task_work(&t->utask->dup_xol_work, dup_xol_work); - task_work_add(t, &t->utask->dup_xol_work, true); + task_work_add(t, &t->utask->dup_xol_work, TWA_RESUME); } /* diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 5df903fccb60..c460e0496006 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -1162,7 +1162,7 @@ static int irq_thread(void *data) handler_fn = irq_thread_fn; init_task_work(&on_exit_work, irq_thread_dtor); - task_work_add(current, &on_exit_work, false); + task_work_add(current, &on_exit_work, TWA_NONE); irq_thread_check_affinity(desc, action); diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index aa4c6227cd6d..e17012be4d14 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -2928,7 +2928,7 @@ static void task_tick_numa(struct rq *rq, struct task_struct *curr) curr->node_stamp += period; if (!time_before(jiffies, curr->mm->numa_next_scan)) - task_work_add(curr, work, true); + task_work_add(curr, work, TWA_RESUME); } } diff --git a/kernel/task_work.c b/kernel/task_work.c index 613b2d634af8..8d6e1217c451 100644 --- a/kernel/task_work.c +++ b/kernel/task_work.c @@ -9,23 +9,28 @@ static struct callback_head work_exited; /* all we need is ->next == NULL */ * task_work_add - ask the @task to execute @work->func() * @task: the task which should run the callback * @work: the callback to run - * @notify: send the notification if true + * @notify: how to notify the targeted task * - * Queue @work for task_work_run() below and notify the @task if @notify. - * Fails if the @task is exiting/exited and thus it can't process this @work. - * Otherwise @work->func() will be called when the @task returns from kernel - * mode or exits. + * Queue @work for task_work_run() below and notify the @task if @notify + * is @TWA_RESUME or @TWA_SIGNAL. @TWA_SIGNAL works like signals, in that the + * it will interrupt the targeted task and run the task_work. @TWA_RESUME + * work is run only when the task exits the kernel and returns to user mode, + * or before entering guest mode. Fails if the @task is exiting/exited and thus + * it can't process this @work. Otherwise @work->func() will be called when the + * @task goes through one of the aforementioned transitions, or exits. * - * This is like the signal handler which runs in kernel mode, but it doesn't - * try to wake up the @task. + * If the targeted task is exiting, then an error is returned and the work item + * is not queued. It's up to the caller to arrange for an alternative mechanism + * in that case. * - * Note: there is no ordering guarantee on works queued here. + * Note: there is no ordering guarantee on works queued here. The task_work + * list is LIFO. * * RETURNS: * 0 if succeeds or -ESRCH. */ -int -task_work_add(struct task_struct *task, struct callback_head *work, int notify) +int task_work_add(struct task_struct *task, struct callback_head *work, + enum task_work_notify_mode notify) { struct callback_head *head; unsigned long flags; @@ -38,6 +43,8 @@ task_work_add(struct task_struct *task, struct callback_head *work, int notify) } while (cmpxchg(&task->task_works, head, work) != head); switch (notify) { + case TWA_NONE: + break; case TWA_RESUME: set_notify_resume(task); break; @@ -54,6 +61,9 @@ task_work_add(struct task_struct *task, struct callback_head *work, int notify) unlock_task_sighand(task, &flags); } break; + default: + WARN_ON_ONCE(1); + break; } return 0; |