Messages in this thread | | | Date | Tue, 23 Aug 2016 10:45:19 +0200 | From | Peter Zijlstra <> | Subject | Re: perf: fuzzer crashes immediately on AMD system |
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On Mon, Aug 22, 2016 at 10:54:32PM -0400, Vince Weaver wrote: > > > > > > > > > > perf stat -a -e amd_nb/config=0x37,config1=0x20/ /bin/ls > > amd_uncore_find_online_sibling() > > function is broken. > > and that's the problem. uncore_find_online_sibling() does all kinds of > wrong things including sticking active uncore structures in > uncore->free_when_cpu_online > > Then uncore_online() comes along and frees those structures. > > Then some other part of the kernel comes and re-uses the free'd data. > > Then when we try to start an event, all of the fields are invalid because > the uncore pointer is pointing to re-used data. > > I don't have a patch because I am not 100% clear on what > uncore_find_online_sibling() is doing in the first place.
Thanks for doing all that, I'll see if I can make sense of it.
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