Messages in this thread | | | Date | Mon, 10 Oct 2011 08:08:10 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH 07/12] perf_events: add LBR software filter support for Intel X86 |
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* Andi Kleen <andi@firstfloor.org> wrote:
> On Thu, Oct 06, 2011 at 06:43:44PM +0200, Peter Zijlstra wrote: > > On Thu, 2011-10-06 at 17:32 +0200, Andi Kleen wrote: > > > > + kernel_insn_init(&insn, kaddr); > > > > + insn_get_opcode(&insn); > > > > > > This makes me uncomfortable. AFAIK that's the first use of the opcode > > > decoder being used directly for user space. It has a quite large attack > > > surface. Who says it cannot be exploited? > > > > You mean: > > arch/x86/kernel/cpu/perf_event_intel_ds.c:intel_pmu_pebs_fixup_ip() > > doesn't use the opcode decoder on user space code? > > True it does. Ok the second.
That's what matters.
> I know uprobes is planning it too, so the problem has to be handled > eventually. > > Still it makes me uncomfortable.
FUD is not how we approach these things - you need to say something specific.
Thanks,
Ingo
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