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From: "Liang, Kan" <kan.liang@linux.intel.com>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Andi Kleen <ak@linux.intel.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Stephane Eranian <eranian@google.com>,
	Namhyung Kim <namhyung@kernel.org>
Subject: Re: [PATCH V3 2/2] perf/x86: Reset the dirty counter to prevent the leak for an RDPMC task
Date: Tue, 13 Apr 2021 21:30:51 -0400	[thread overview]
Message-ID: <ced00596-20af-65b5-9e76-a23456215a64@linux.intel.com> (raw)
In-Reply-To: <CALCETrVVPzUd_hQ8xoomHn_wWRQJUvROeCt2do4_D4ROZoAVMg@mail.gmail.com>



On 4/13/2021 8:34 PM, Andy Lutomirski wrote:
> On Tue, Apr 13, 2021 at 12:05 PM <kan.liang@linux.intel.com> wrote:
>>
>> From: Kan Liang <kan.liang@linux.intel.com>
>>
>> The counter value of a perf task may leak to another RDPMC task.
>> For example, a perf stat task as below is running on CPU 0.
>>
>>      perf stat -e 'branches,cycles' -- taskset -c 0 ./workload
> 
> I assume this doesn't fix the leak if the sensitive counter is systemwide?
>

Right.

> Could Intel please add proper security and ideally virtualization for
> this?  Ideally RDPMC permission would be a bitmask for all RDPMC-able
> counters, not just a single on/off switch.
> 

Yes, we are working on it.

For now, I think this patch is what we can do so far.

Thanks,
Kan


  reply	other threads:[~2021-04-14  1:31 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-13 18:57 [PATCH V3 1/2] perf/x86: Move cpuc->running into P4 specific code kan.liang
2021-04-13 18:57 ` [PATCH V3 2/2] perf/x86: Reset the dirty counter to prevent the leak for an RDPMC task kan.liang
2021-04-13 20:33   ` kernel test robot
2021-04-14 13:47     ` Liang, Kan
2021-04-13 23:41   ` kernel test robot
2021-04-14  0:34   ` Andy Lutomirski
2021-04-14  1:30     ` Liang, Kan [this message]
2021-04-14 13:51   ` Namhyung Kim
2021-04-14 14:27     ` Liang, Kan
2021-04-14 12:22 ` [PATCH V3 1/2] perf/x86: Move cpuc->running into P4 specific code Peter Zijlstra

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