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Date:   Wed, 3 Aug 2022 19:33:39 +0200
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Subject: Re: [PATCH] x86/fpu: Allow PKRU to be (once again) written by ptrace.
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To:     Ingo Molnar <mingo@kernel.org>, Kyle Huey <me@kylehuey.com>
Cc:     Dave Hansen <dave.hansen@linux.intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Borislav Petkov <bp@alien8.de>, Ingo Molnar <mingo@redhat.com>,
        x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
        Andy Lutomirski <luto@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        linux-kernel@vger.kernel.org,
        Robert O'Callahan <robert@ocallahan.org>,
        David Manouchehri <david.manouchehri@riseup.net>,
        kvm@vger.kernel.org, stable@vger.kernel.org
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From:   Paolo Bonzini <pbonzini@redhat.com>
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On 8/3/22 19:25, Ingo Molnar wrote:
> Ok - allowing ptrace to set the full 32 bits of the PKRU register seems OK
> then, and is 100% equivalent to using WRPKRU, right? So there's no implicit
> masking/clearing of bits depending on how many keys are available, or other
> details where WRPKRU might differ from a pure 32-bit per thread write,
> correct?

Yes, it's the same.

Paolo