From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-la0-f44.google.com ([209.85.215.44]:33037 "EHLO mail-la0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751696AbbGAM7n (ORCPT ); Wed, 1 Jul 2015 08:59:43 -0400 Received: by laar3 with SMTP id r3so40252227laa.0 for ; Wed, 01 Jul 2015 05:59:41 -0700 (PDT) Date: Wed, 1 Jul 2015 14:59:44 +0200 From: Christoffer Dall To: Steve Capper Cc: "linux-arm-kernel@lists.infradead.org" , Alexander Graf , Marc Zyngier , Catalin Marinas , kvmarm@lists.cs.columbia.edu, Dirk =?iso-8859-1?Q?M=FCller?= , stable@vger.kernel.org Subject: Re: [PATCH] arm64: Don't report clear pmds and puds as huge Message-ID: <20150701125944.GA7625@cbox> References: <1435752511-7079-1-git-send-email-christoffer.dall@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: stable-owner@vger.kernel.org List-ID: On Wed, Jul 01, 2015 at 01:24:34PM +0100, Steve Capper wrote: > On 1 July 2015 at 13:08, Christoffer Dall wrote: > > The current pmd_huge() and pud_huge() functions simply check if the table > > bit is not set and reports the entries as huge in that case. This is > > counter-intuitive as a clear pmd/pud cannot also be a huge pmd/pud, and > > it is inconsistent with at least arm and x86. > > > > To prevent others from making the same mistake as me in looking at code > > that calls these functions and to fix an issue with KVM on arm64 that > > causes memory corruption due to incorrect page reference counting > > resulting from this mistake, let's change the behavior. > > > > Cc: stable@vger.kernel.org > > Thanks Christoffer. > > It may be worth adding: > > Fixes: 084bd29810a5 ("ARM64: mm: HugeTLB support.") > > And, please feel free to add: > > Reviewed-by: Steve Capper > Thanks! -Christoffer