linux-kernel - Re: [PATCH v2 03/13] perf/x86/amd: add AMD Fam19h Branch Sampling support

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: <CABPqkBShSBaJH+PR6rMkRRzjZAKN5zPhcdnLWx=4a-yQWxcA2A@mail.gmail.com>
Date:   Mon, 15 Nov 2021 23:48:01 -0800
From:   Stephane Eranian <eranian@...gle.com>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     linux-kernel@...r.kernel.org, kim.phillips@....com,
        acme@...hat.com, jolsa@...hat.com, songliubraving@...com,
        mpe@...erman.id.au, maddy@...ux.ibm.com
Subject: Re: [PATCH v2 03/13] perf/x86/amd: add AMD Fam19h Branch Sampling support

On Fri, Nov 12, 2021 at 8:02 AM Peter Zijlstra <peterz@...radead.org> wrote:
>
> On Thu, Nov 11, 2021 at 12:44:05AM -0800, Stephane Eranian wrote:
> > diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
> > index 38b2c779146f..28559557f966 100644
> > --- a/arch/x86/events/core.c
> > +++ b/arch/x86/events/core.c
> > @@ -683,11 +683,16 @@ void x86_pmu_disable_all(void)
> >
> >               if (!test_bit(idx, cpuc->active_mask))
> >                       continue;
> > +
> > +             if (is_amd_brs(hwc))
> > +                     amd_brs_disable();
> > +
> >               rdmsrl(x86_pmu_config_addr(idx), val);
> >               if (!(val & ARCH_PERFMON_EVENTSEL_ENABLE))
> >                       continue;
> >               val &= ~ARCH_PERFMON_EVENTSEL_ENABLE;
> >               wrmsrl(x86_pmu_config_addr(idx), val);
> > +
> >               if (is_counter_pair(hwc))
> >                       wrmsrl(x86_pmu_config_addr(idx + 1), 0);
> >       }
>
> Please, stick that in amd_pmu_disable_all().


If I do that, I need to add a for_each_counter() loop to
amd_pmu_disable_all() but it does not have one call systematically.
If you are okay with it, then I am fine as well.