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From:   Andy Lutomirski <luto@kernel.org>
Date:   Wed, 5 Sep 2018 14:39:22 -0700
Message-ID: <CALCETrWBtQLRE69+YB2F3GUrnFQ6bXsq2LFCsh6-tFRkj=fTtw@mail.gmail.com>
Subject: Re: [PATCH] x86/pkeys: Explicitly treat PK #PF on kernel address as a
 bad area
To:     Dave Hansen <dave.hansen@intel.com>
Cc:     Andy Lutomirski <luto@kernel.org>,
        Sean Christopherson <sean.j.christopherson@intel.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>,
        "H. Peter Anvin" <hpa@zytor.com>, X86 ML <x86@kernel.org>,
        Jann Horn <jannh@google.com>
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On Wed, Sep 5, 2018 at 2:35 PM, Dave Hansen <dave.hansen@intel.com> wrote:
> On 09/04/2018 02:27 PM, Andy Lutomirski wrote:
>> Also, I doubt it matters right here, but !X86_PF_USER isn't quite the
>> same thing as "originating from kernel code" -- it can also be user
>> code that does a CPL0 access due to exception delivery or access to a
>> descriptor table.  Which you saw plenty of times while debugging
>> PTI... :)  I doubt any of those should be spurious, though.
>
> Yeah, you're talking about "implicit supervisor access".  Right?

Yes.