Messages in this thread |  | | | Subject | Re: lockdep trace from posix timers | | From | Peter Zijlstra <> | | Date | Mon, 20 Aug 2012 17:10:34 +0200 |
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On Mon, 2012-08-20 at 16:59 +0200, Oleg Nesterov wrote: > On 08/20, Peter Zijlstra wrote: > > > > task_work_cancel(struct task_struct *task, task_work_func_t func) > > { > > ... > > + > > +again: > > + workp = &task->task_works; > > + work = *workp; > > + while (work) { > > + if (work->func == func) { > > But this all can race with task_work_run() if task != current. > > This "work" can be freed/reused. And it should only return !NULL > if twork->func() was not called.
Ah, because we could be iterating the list after the xchg done by run.
Hmm..
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