From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-f200.google.com (mail-qt0-f200.google.com [209.85.216.200]) by kanga.kvack.org (Postfix) with ESMTP id 91E096B0009 for ; Tue, 20 Mar 2018 17:35:36 -0400 (EDT) Received: by mail-qt0-f200.google.com with SMTP id y17so1935334qth.11 for ; Tue, 20 Mar 2018 14:35:36 -0700 (PDT) Received: from aserp2130.oracle.com (aserp2130.oracle.com. [141.146.126.79]) by mx.google.com with ESMTPS id r64si3878284qkf.331.2018.03.20.14.35.35 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 20 Mar 2018 14:35:35 -0700 (PDT) Subject: Re: [PATCH] mm/hugetlb: prevent hugetlb VMA to be misaligned From: Mike Kravetz References: <1521566754-30390-1-git-send-email-ldufour@linux.vnet.ibm.com> <86240c1a-d1f1-0f03-855e-c5196762ec0a@oracle.com> Message-ID: <0d24f817-303a-7b4d-4603-b2d14e4b391a@oracle.com> Date: Tue, 20 Mar 2018 14:35:28 -0700 MIME-Version: 1.0 In-Reply-To: <86240c1a-d1f1-0f03-855e-c5196762ec0a@oracle.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Laurent Dufour , akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrea Arcangeli , mhocko@kernel.org, Dan Williams On 03/20/2018 02:26 PM, Mike Kravetz wrote: > Thanks Laurent! > > This bug was introduced by 31383c6865a5. Dan's changes for 31383c6865a5 > seem pretty straight forward. It simply replaces an explicit check when > splitting a vma to a new vm_ops split callout. Unfortunately, mappings > created via shmget/shmat have their vm_ops replaced. Therefore, this > split callout is never made. > > The shm vm_ops do indirectly call the original vm_ops routines as needed. > Therefore, I would suggest a patch something like the following instead. > If we move forward with the patch, we should include Laurent's BUG output > and perhaps test program in the commit message. Sorry, patch in previous mail was a mess