From: Andi Kleen <andi@firstfloor.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Andi Kleen <andi@firstfloor.org>,
linux-kernel@vger.kernel.org,
Stephane Eranian <eranian@google.com>,
Ingo Molnar <mingo@kernel.org>,
Vince Weaver <vincent.weaver@maine.edu>
Subject: Re: BUG uncore_assign_events
Date: Wed, 10 Sep 2014 23:59:08 +0200 [thread overview]
Message-ID: <20140910215908.GL4120@two.firstfloor.org> (raw)
In-Reply-To: <20140910091626.GO16043@twins.programming.kicks-ass.net>
> # addr2line -i -e ivb-ep-build/vmlinux ffffffff81025f18
>
> arch/x86/include/asm/bitops.h:318
> arch/x86/kernel/cpu/perf_event_intel_uncore.c:3339
i == zero (ok)
c points to some kernel looking address
hwc->idx is 64
/* fastpath, try to reuse previous register */
for (i = 0; i < n; i++) {
hwc = &box->event_list[i]->hw;
c = hwc->constraint;
/* never assigned */
if (hwc->idx == -1)
break;
/* constraint still honored */
if (!test_bit(hwc->idx, c->idxmsk))
break;
My best bet is something goes wrong in uncore_pmu_to_box or
uncore_event_to_pmu in hte caller, so the box is bogus.
Did the test do CPU hot plug?
BTW i don't think it's a security issue because the uncore driver
is only accesible for root.
-Andi
--
ak@linux.intel.com -- Speaking for myself only.
next prev parent reply other threads:[~2014-09-10 21:59 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-10 9:16 BUG uncore_assign_events Peter Zijlstra
2014-09-10 21:59 ` Andi Kleen [this message]
2014-09-11 5:29 ` Chuck Ebbert
2014-09-11 19:21 ` Andi Kleen
2014-09-11 8:11 ` Peter Zijlstra
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