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From: Vince Weaver <vincent.weaver@maine.edu>
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Date: Thu, 18 Aug 2016 10:46:31 -0400 (EDT)
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cc: Borislav Petkov <bp@suse.de>, Peter Zijlstra <peterz@infradead.org>,
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        Arnaldo Carvalho de Melo <acme@kernel.org>
Subject: Re: perf: fuzzer crashes immediately on AMD system
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On Thu, 18 Aug 2016, Vince Weaver wrote:

> Tried the perf_fuzzer on my A10 fam15h/model13h system with 4.8-rc2 and it
> falls over more or less immediately.
> 
> This maps to variable_test_bit()
> 	called by ctx = find_get_context(pmu, task, event);
> 		in kernel/events/core.c:9467
> 
> It happens quickly enough I can probably track down the exact event that 
> causes this, if needed.

I have a one line reproducer:

	perf stat -a -e amd_nb/config=0x37,config1=0x20/ /bin/ls