Messages in this thread | | | From | Vince Weaver <> | Date | Fri, 8 May 2015 00:25:50 -0400 (EDT) | Subject | Re: perf: fuzzer triggers NULL pointer derefreence in x86_schedule_events |
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On Thu, 7 May 2015, Peter Zijlstra wrote:
> Indeed so; and we can make an analogous argument for hwc. However: > > > I think it is more likely related to the bitmask (idxmsk). But then > > it is always allocated with the constraint even with the HT bug > > workaround. So most, likely the index is bogus and you touch outside > > the idxmsk[] array. > > [428232.701319] BUG: unable to handle kernel NULL pointer dereference at (null) > > But the thing really tried to touch NULL, not some random address that > faulted. > > As always, Vince has found us a good puzzle ;-)
and sorry I haven't been much help tracking it down. I'm trying to trigger it again, but this particular bug only pops up after a week or so of fuzzing.
Vince
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