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From:   Brian Geffon <bgeffon@google.com>
Date:   Tue, 15 Feb 2022 16:48:44 -0500
Message-ID: <CADyq12w=oLp4a5CV6nCyrpijDQTeji5reE+w_F4Ha=qCJEsBGQ@mail.gmail.com>
Subject: Re: [PATCH stable 5.4,5.10] x86/fpu: Correct pkru/xstate inconsistency
To:     Dave Hansen <dave.hansen@intel.com>
Cc:     Greg KH <gregkh@linuxfoundation.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Willis Kung <williskung@google.com>,
        Guenter Roeck <groeck@google.com>,
        Borislav Petkov <bp@suse.de>,
        Andy Lutomirski <luto@kernel.org>,
        "# v4 . 10+" <stable@vger.kernel.org>,
        "the arch/x86 maintainers" <x86@kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
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On Tue, Feb 15, 2022 at 4:42 PM Dave Hansen <dave.hansen@intel.com> wrote:
>
> On 2/15/22 13:32, Brian Geffon wrote:
> >> How was this tested, and what do the maintainers of this subsystem
> >> think?  And will you be around to fix the bugs in this when they are
> >> found?
> > This has been trivial to reproduce, I've used a small repro which I've
> > put here: https://gist.github.com/bgaff/9f8cbfc8dd22e60f9492e4f0aff8f04f
> > , I also was able to reproduce this using the protection_keys self
> > tests on a 11th Gen Core i5-1135G7.
>
> I've got an i7-1165G7, but I'm not seeing any failures on a
> 5.11 distro kernel.
>
> How long does this take for you to reproduce?

It reproduces for me in just a few seconds. I'm not sure what could be
different about my setup, I've tested on a vanilla 5.10 kernel and it
reproduced the same way.

Brian