Messages in this thread | | | Date | Thu, 22 Jan 2015 04:39:16 -0800 | Subject | Re: perf: easily crash kernel with rapl event close | From | Stephane Eranian <> |
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On Thu, Jan 22, 2015 at 2:17 AM, Peter Zijlstra <peterz@infradead.org> wrote: > 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.
I will fix that today.
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