1 #include <linux/spinlock.h>
2 #include <linux/task_work.h>
3 #include <linux/tracehook.h>
6 task_work_add(struct task_struct *task, struct task_work *twork, bool notify)
11 #ifndef TIF_NOTIFY_RESUME
16 * We must not insert the new work if the task has already passed
17 * exit_task_work(). We rely on do_exit()->raw_spin_unlock_wait()
18 * and check PF_EXITING under pi_lock.
20 raw_spin_lock_irqsave(&task->pi_lock, flags);
21 if (likely(!(task->flags & PF_EXITING))) {
22 hlist_add_head(&twork->hlist, &task->task_works);
25 raw_spin_unlock_irqrestore(&task->pi_lock, flags);
27 /* test_and_set_bit() implies mb(), see tracehook_notify_resume(). */
28 if (likely(!err) && notify)
29 set_notify_resume(task);
34 task_work_cancel(struct task_struct *task, task_work_func_t func)
37 struct task_work *twork;
38 struct hlist_node *pos;
40 raw_spin_lock_irqsave(&task->pi_lock, flags);
41 hlist_for_each_entry(twork, pos, &task->task_works, hlist) {
42 if (twork->func == func) {
43 hlist_del(&twork->hlist);
49 raw_spin_unlock_irqrestore(&task->pi_lock, flags);
54 void task_work_run(void)
56 struct task_struct *task = current;
57 struct hlist_head task_works;
58 struct hlist_node *pos;
60 raw_spin_lock_irq(&task->pi_lock);
61 hlist_move_list(&task->task_works, &task_works);
62 raw_spin_unlock_irq(&task->pi_lock);
64 if (unlikely(hlist_empty(&task_works)))
67 * We use hlist to save the space in task_struct, but we want fifo.
68 * Find the last entry, the list should be short, then process them
71 for (pos = task_works.first; pos->next; pos = pos->next)
75 struct hlist_node **pprev = pos->pprev;
76 struct task_work *twork = container_of(pos, struct task_work,
80 if (pprev == &task_works.first)
82 pos = container_of(pprev, struct hlist_node, next);