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Date:   Sun, 11 Apr 2021 09:43:42 -0700
From:   Andi Kleen <ak@linux.intel.com>
To:     Andy Lutomirski <luto@amacapital.net>
Cc:     Borislav Petkov <bp@alien8.de>,
        Thomas Gleixner <tglx@linutronix.de>,
        Feng Tang <feng.tang@intel.com>,
        Ingo Molnar <mingo@redhat.com>,
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        Peter Zijlstra <peterz@infradead.org>, X86 ML <x86@kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        "Zhang, Rui" <rui.zhang@intel.com>,
        "Kleen, Andi" <andi.kleen@intel.com>,
        Dave Hansen <dave.hansen@intel.com>,
        Len Brown <len.brown@intel.com>
Subject: Re: [PATCH] x86/msr: Block writes to certain MSRs unconditionally
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> I have actually seen real user programs poke MSR_SYSCALL_MASK.

Hmm, what was the use case?

-Andi