Messages in this thread | | | Date | Thu, 22 Jan 2015 11:17:20 +0100 | From | Peter Zijlstra <> | Subject | Re: perf: easily crash kernel with rapl event close |
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On Wed, Jan 21, 2015 at 09:13:11PM -0800, Stephane Eranian wrote: > Vince, > > On Wed, Jan 21, 2015 at 10:55 AM, Vince Weaver <vincent.weaver@maine.edu> wrote: > > Hello > > > > on my haswell system, running 3.19-rc5, and with > > echo "0" > /proc/sys/kernel/perf_event_paranoid > > > > I can easily crash my system with the attached test program that simply > > opens a RAPL event and then closes it. > > > > This bug was found by the perf_fuzzer. > > > > It looks like somehow rapl_pmu gets freed to NULL but the > > call in rapl_scale() > > __this_cpu_read(rapl_pmu->hw_unit) > > still happens. > > > I don't see how this can happen. > > I get some crashes but not with your program on my laptop. > But I cannot catch the serial console from my laptop. > Will try with another machine tomorrow.
I saw it today as well on an ivb-ep. I disabled rapl for now since I'm chasing other things.
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