From: Peter Zijlstra <peterz@infradead.org>
To: Stephane Eranian <eranian@google.com>
Cc: Andi Kleen <andi@firstfloor.org>,
linux-kernel@vger.kernel.org, mingo@elte.hu, acme@redhat.com,
ming.m.lin@intel.com, robert.richter@amd.com, ravitillo@lbl.gov
Subject: Re: [PATCH 07/12] perf_events: add LBR software filter support for Intel X86
Date: Fri, 07 Oct 2011 13:18:26 +0200 [thread overview]
Message-ID: <1317986306.31132.10.camel@twins> (raw)
In-Reply-To: <CABPqkBTxxS-vuAycDJO-aJNE4EpCLF8xyPtJ1Jzv26f15HJC8A@mail.gmail.com>
On Fri, 2011-10-07 at 12:49 +0200, Stephane Eranian wrote:
> > You could still fuzz it after the cpu passed through and before the
> > kernel reads the LBR. Its a narrow window, but quite feasible.
> >
> Yeah, depending on the depth of the LBR. But then what happens, you
> decode an instruction that is not what was executed.
Right, and Andi's concern is that this might cause our instruction
decoder to blow up, or worse.
The whole false profile thing isn't really a problem, I mean, that's
what you get for poking at your own instruction stream.
next prev parent reply other threads:[~2011-10-07 11:18 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-06 14:49 [PATCH 00/12] perf_events: add support for sampling taken branches Stephane Eranian
2011-10-06 14:49 ` [PATCH 01/12] perf_events: add generic taken branch sampling support Stephane Eranian
2011-10-06 16:57 ` Peter Zijlstra
2011-10-07 10:28 ` Stephane Eranian
2011-10-07 10:32 ` Peter Zijlstra
2011-10-07 10:44 ` Stephane Eranian
2011-10-06 17:01 ` Peter Zijlstra
2011-10-06 14:49 ` [PATCH 02/12] perf_events: add Intel LBR MSR definitions Stephane Eranian
2011-10-06 14:49 ` [PATCH 03/12] perf_events: add Intel X86 LBR sharing logic Stephane Eranian
2011-10-06 14:49 ` [PATCH 04/12] perf_events: sync branch stack sampling with X86 precise_sampling Stephane Eranian
2011-10-06 17:25 ` Peter Zijlstra
2011-10-07 10:34 ` Stephane Eranian
2011-10-07 10:37 ` Peter Zijlstra
2011-10-06 14:49 ` [PATCH 05/12] perf_events: add LBR mappings for PERF_SAMPLE_BRANCH filters Stephane Eranian
2011-10-06 14:49 ` [PATCH 06/12] perf_events: implement PERF_SAMPLE_BRANCH for Intel X86 Stephane Eranian
2011-10-06 17:54 ` Peter Zijlstra
2011-10-06 18:05 ` Peter Zijlstra
2011-10-06 14:49 ` [PATCH 07/12] perf_events: add LBR software filter support " Stephane Eranian
2011-10-06 15:32 ` Andi Kleen
2011-10-06 16:43 ` Peter Zijlstra
2011-10-06 17:14 ` Andi Kleen
2011-10-10 6:08 ` Ingo Molnar
2011-10-10 9:39 ` Peter Zijlstra
2011-10-07 7:06 ` Masami Hiramatsu
2011-10-07 10:38 ` Stephane Eranian
2011-10-07 10:40 ` Stephane Eranian
2011-10-07 10:42 ` Peter Zijlstra
2011-10-07 10:49 ` Stephane Eranian
2011-10-07 11:18 ` Peter Zijlstra [this message]
2011-10-07 11:21 ` Peter Zijlstra
2011-10-07 11:54 ` Masami Hiramatsu
2011-10-07 13:31 ` [PATCH] x86: Fix insn decoder for longer instruction Masami Hiramatsu
2011-10-10 7:04 ` Ingo Molnar
2011-10-10 6:09 ` [PATCH 07/12] perf_events: add LBR software filter support for Intel X86 Ingo Molnar
2011-10-10 14:05 ` Masami Hiramatsu
2011-10-10 14:45 ` Andi Kleen
2011-10-11 12:59 ` Masami Hiramatsu
2011-10-12 7:06 ` Ingo Molnar
2011-10-13 10:54 ` Masami Hiramatsu
2011-10-13 11:01 ` [RFC PATCH] x86: Add a sanity test of x86 decoder Masami Hiramatsu
2011-10-18 6:54 ` Ingo Molnar
2011-10-19 4:29 ` Masami Hiramatsu
2011-10-19 6:44 ` Ingo Molnar
2011-10-20 14:01 ` [RFC PATCH v2 1/2] " Masami Hiramatsu
2011-11-18 23:16 ` [tip:perf/core] x86, perf: Add a build-time sanity test to the " tip-bot for Masami Hiramatsu
2011-10-20 14:01 ` [RFC PATCH v2 2/2] [RESEND] x86: Fix insn decoder for longer instruction Masami Hiramatsu
2011-10-07 15:42 ` [PATCH 07/12] perf_events: add LBR software filter support for Intel X86 Andi Kleen
2011-10-07 11:25 ` Masami Hiramatsu
2011-10-07 11:40 ` Peter Zijlstra
2011-10-07 15:44 ` Andi Kleen
2011-10-07 15:09 ` Andi Kleen
2011-10-07 16:05 ` Peter Zijlstra
2011-10-06 14:49 ` [PATCH 08/12] perf_events: disable PERF_SAMPLE_BRANCH_* when not supported Stephane Eranian
2011-10-06 18:53 ` Peter Zijlstra
2011-10-06 14:49 ` [PATCH 09/12] perf_events: add hook to flush branch_stack on context switch Stephane Eranian
2011-10-06 14:49 ` [PATCH 10/12] perf: add code to support PERF_SAMPLE_BRANCH_STACK Stephane Eranian
2011-10-06 18:50 ` Peter Zijlstra
2011-10-07 10:25 ` Stephane Eranian
2011-10-07 10:27 ` Peter Zijlstra
2011-10-06 14:49 ` [PATCH 11/12] perf: add support for sampling taken branch to perf record Stephane Eranian
2011-10-06 14:49 ` [PATCH 12/12] perf: add support for taken branch sampling to perf report Stephane Eranian
2011-10-06 15:25 ` [PATCH 00/12] perf_events: add support for sampling taken branches Andi Kleen
2011-10-07 10:23 ` Stephane Eranian
2011-10-06 18:32 ` Peter Zijlstra
2011-10-06 21:41 ` Stephane Eranian
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