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From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Fri, 19 Jan 2018 18:38:44 -0800
Message-ID: <CA+55aFy3Agx5ngYERyJZhLkgA1oP1e48VY4hPw0H5Yopw_GdGA@mail.gmail.com>
Subject: Re: Boot regression with bacf6b499e11 ("x86/mm: Use a struct to
 reduce parameters for SME PGD mapping") on top of -rc8
To:     Laura Abbott <labbott@redhat.com>
Cc:     Tom Lendacky <thomas.lendacky@amd.com>,
        Borislav Petkov <bp@suse.de>,
        Peter Zijlstra <peterz@infradead.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@kernel.org>,
        Brijesh Singh <brijesh.singh@amd.com>, X86 ML <x86@kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Fri, Jan 19, 2018 at 5:23 PM, Laura Abbott <labbott@redhat.com> wrote:
>
> Fedora got multiple reports of an early bootup crash post -rc8.
> Bisection showed bacf6b499e11 ("x86/mm: Use a struct to reduce
> parameters for SME PGD mapping") . It doesn't revert cleanly
> but if I revert the few other changes in arch/x86/mm/mem_encrypt.c
> as well it boots up fine.

Odd. I've tried to read through that patch three times to find
anything it actually changes, and I can't find anything.

It looks like that patch should have absolutely no actual behavioral impact.

But clearly I'm missing something. Can anybody see what the mistake in
the conversion is?

             Linus