linux-kernel - Re: [PATCH 2/8] perf metrics: fix parse errors in cascade lake metrics

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 23 Apr 2020 13:53:54 +0800
From:   "Jin, Yao" <yao.jin@...ux.intel.com>
To:     Ian Rogers <irogers@...gle.com>, Andi Kleen <ak@...ux.intel.com>,
        Jiri Olsa <jolsa@...hat.com>
Cc:     Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Namhyung Kim <namhyung@...nel.org>,
        Kan Liang <kan.liang@...ux.intel.com>,
        Haiyan Song <haiyanx.song@...el.com>,
        Ravi Bangoria <ravi.bangoria@...ux.ibm.com>,
        John Garry <john.garry@...wei.com>,
        Leo Yan <leo.yan@...aro.org>,
        Adrian Hunter <adrian.hunter@...el.com>,
        LKML <linux-kernel@...r.kernel.org>,
        linux-perf-users <linux-perf-users@...r.kernel.org>,
        Stephane Eranian <eranian@...gle.com>
Subject: Re: [PATCH 2/8] perf metrics: fix parse errors in cascade lake
 metrics

Hi Jiri,

Bisected to this commit which introduced the regression.

26226a97724d ("perf expr: Move expr lexer to flex")

Would you like to look at that?

Thanks
Jin Yao

On 4/23/2020 9:08 AM, Jin, Yao wrote:
> 
> 
> On 4/23/2020 12:18 AM, Ian Rogers wrote:
>> On Wed, Apr 22, 2020 at 8:34 AM Ian Rogers <irogers@...gle.com> wrote:
>>>
>>> On Wed, Apr 22, 2020 at 7:38 AM Andi Kleen <ak@...ux.intel.com> wrote:
>>>>
>>>> On Wed, Apr 22, 2020 at 12:48:03AM -0700, Ian Rogers wrote:
>>>>> Remove over escaping with \\.
>>>>> Remove extraneous if 1 if 0 == 1 else 0 else 0.
>>>>
>>>> So where do these parse errors happen exactly? Some earlier
>>>> patches introduced them as regressions?
>>>
>>> I'll work to track down a Fixes tag. I can repro the Skylakex errors
>>> without the test in this series, by doing:
>>>
>>> $ perf stat -M DRAM_Read_Latency sleep 1
>>> Error:
>>> The sys_perf_event_open() syscall returned with 22 (Invalid argument)
>>> for event (cha/event=0x36\,uma
>>> sk=0x21/).
>>> /bin/dmesg | grep -i perf may provide additional information.
>>>
> 
> I also think some patches introduced this regression. When we rollback 
> to commit 61ec07f5917e (perf vendor events intel: Update all the Intel 
> JSON metrics from TMAM 3.6.), there is no this error on CLX.
> 
> Thanks
> Jin Yao
> 
>>> This was just the escaping issue. I'm less clear on the other cascade
>>> lake issue, and it is a bit more work for me to test on cascade lake.
>>> What is "if 1 if 0 == 1 else 0 else 0" trying to do? Perhaps hunting
>>> for the Fixes will let me know, but it looks like a copy-paste error.
>>>
>>>> The original metrics worked without parse errors as far as I know.
>>>
>>> The skylake issue above repros on 5.2.17 and so it seems like it is
>>> broken for a while. The test in this series will prevent this in the
>>> future, but without this patch that test fails.
>>
>> The parse errors were introduced with the metrics, so they've never 
>> worked:
>> https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?id=fd5500989c8f3c3944ac0a144be04bae2506f7ba 
>>
>>
>> I will send out a v2 with Fixes in the commit message but wanted to
>> wait in case there was any more feedback. In particular the fixes to
>> the new test and expr parser lex code. The lex code wasn't broken at
>> the time the metrics were added and should be working again after this
>> patch set.
>>
>> Thanks,
>> Ian
>>
>>>> If it fixes something earlier it would need Fixes: tags.
>>>
>>> Working on it. Thanks for the input!
>>>
>>> Ian
>>>
>>>> -Andi