Messages in this thread | | | Date | Wed, 27 Mar 2013 14:15:32 +0100 | From | Joerg Roedel <> | Subject | Re: BUG: using smp_processor_id() in preemptible [00000000] code: asm/8267 |
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On Tue, Mar 26, 2013 at 07:34:52PM +0100, Borislav Petkov wrote: > diff --git a/kernel/events/core.c b/kernel/events/core.c > index 7b4a55d41efc..f3bb3384a106 100644 > --- a/kernel/events/core.c > +++ b/kernel/events/core.c > @@ -4455,8 +4455,11 @@ static void perf_event_task_event(struct perf_task_event *task_event) > next: > put_cpu_ptr(pmu->pmu_cpu_context); > } > + > + preempt_disable(); > if (task_event->task_ctx) > perf_event_task_ctx(task_event->task_ctx, task_event); > + preempt_enable(); > > rcu_read_unlock(); > }
What makes me wonder here is that the code is preemptible in an rcu_read_locked section. As far as I know preemption needs to be disabled while holding the rcu_read_lock().
Joerg
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