Re: perf/tracepoint: another fuzzer generated lockup

From: Peter Zijlstra
Date: Thu Nov 14 2013 - 12:14:26 EST


On Thu, Nov 14, 2013 at 12:20:35PM -0500, Vince Weaver wrote:
>
> possibly not an issue with your patch, but found in nearby code:
>
> in perf_trace_init:
>
> int event_id = p_event->attr.config;
>
> ...
>
> if (tp_event->event.type == event_id &&
>
>
> note that "attr.config" is 64-bit but "event_id" is only 32-bit,
> so things like 0xffffffff00000018 will map to irq_work_exit.

I will have a look.

> I'm not sure if your PERM code properly handles this case, I don't have
> time to work through the macro-magic in your patch.

Can't blame you; took me a fair chunk of the day to come up with this.
That trace event stuff is horrid.
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