linux-kernel - RE: [PATCH V3 1/5] perf/x86/intel/uncore: customized pmu event read for client IMC uncore

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]

Message-ID: <alpine.DEB.2.20.1711021530250.2090@nanos>
Date:   Thu, 2 Nov 2017 15:56:45 +0100 (CET)
From:   Thomas Gleixner <tglx@...utronix.de>
To:     "Liang, Kan" <kan.liang@...el.com>
cc:     "peterz@...radead.org" <peterz@...radead.org>,
        "mingo@...hat.com" <mingo@...hat.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "acme@...nel.org" <acme@...nel.org>,
        "eranian@...gle.com" <eranian@...gle.com>,
        "ak@...ux.intel.com" <ak@...ux.intel.com>
Subject: RE: [PATCH V3 1/5] perf/x86/intel/uncore: customized pmu event read
 for client IMC uncore

On Thu, 2 Nov 2017, Liang, Kan wrote:
> > On Thu, 2 Nov 2017, Thomas Gleixner wrote:
> > But then you have this in uncore_perf_event_update():
> > 
> > -       if (event->hw.idx >= UNCORE_PMC_IDX_FIXED)
> > +       if (event->hw.idx == UNCORE_PMC_IDX_FIXED)
> > 
> > So how is that supposed to work?
> 
> This is for generic code. 
> 
> In previous code, the event_read function for IMC use generic code.
> So we have to deal with >= in generic code.
> 
> Now, customized event_read function 'snb_uncore_imc_event_read'
>  is introduced for IMC. So IMC does not touch the generic code. 
> The generic code is corrected here.

The customized read function does not help at all.

uncore_perf_event_update() is used from snb_uncore_imc_event_stop(). So
it's broken with this patch.

This is a complete and utter mess to review.

Thanks,

	tglx