From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f197.google.com (mail-qk0-f197.google.com [209.85.220.197]) by kanga.kvack.org (Postfix) with ESMTP id 18FEF6B0008 for ; Wed, 23 May 2018 07:52:11 -0400 (EDT) Received: by mail-qk0-f197.google.com with SMTP id d71-v6so5739013qkg.0 for ; Wed, 23 May 2018 04:52:11 -0700 (PDT) Received: from mx1.redhat.com (mx3-rdu2.redhat.com. [66.187.233.73]) by mx.google.com with ESMTPS id t23-v6si1915838qve.232.2018.05.23.04.52.10 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 23 May 2018 04:52:10 -0700 (PDT) Subject: Re: [PATCH v2 2/2] kasan: fix memory hotplug during boot References: <20180522100756.18478-1-david@redhat.com> <20180522100756.18478-3-david@redhat.com> <09c36096-f8c8-b9e9-0bed-113e494f159a@virtuozzo.com> <20180522140735.71dcd92e7b013629a7f15f91@linux-foundation.org> <6642e0d8-671c-1c1e-3ae8-99ac34c3b667@virtuozzo.com> From: David Hildenbrand Message-ID: <4ec53da0-bdf6-9db4-b70b-6a05c4d40161@redhat.com> Date: Wed, 23 May 2018 13:52:03 +0200 MIME-Version: 1.0 In-Reply-To: <6642e0d8-671c-1c1e-3ae8-99ac34c3b667@virtuozzo.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: Andrey Ryabinin , Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Alexander Potapenko , Dmitry Vyukov , "open list:KASAN" On 23.05.2018 11:59, Andrey Ryabinin wrote: > > > On 05/23/2018 12:07 AM, Andrew Morton wrote: >> On Tue, 22 May 2018 22:50:12 +0300 Andrey Ryabinin wrote: >> >>> >>> >>> On 05/22/2018 07:36 PM, David Hildenbrand wrote: >>>> On 22.05.2018 18:26, Andrey Ryabinin wrote: >>>>> >>>>> >>>>> On 05/22/2018 01:07 PM, David Hildenbrand wrote: >>>>>> Using module_init() is wrong. E.g. ACPI adds and onlines memory before >>>>>> our memory notifier gets registered. >>>>>> >>>>>> This makes sure that ACPI memory detected during boot up will not >>>>>> result in a kernel crash. >>>>>> >>>>>> Easily reproducable with QEMU, just specify a DIMM when starting up. >>>>> >>>>> reproducible >>>>>> >>>>>> Signed-off-by: David Hildenbrand >>>>>> --- >>>>> >>>>> Fixes: fa69b5989bb0 ("mm/kasan: add support for memory hotplug") >>>>> Acked-by: Andrey Ryabinin >>>>> Cc: >>>> >>>> Think this even dates back to: >>>> >>>> 786a8959912e ("kasan: disable memory hotplug") >>>> >>> >>> Indeed. >> >> Is a backport to -stable justified for either of these patches? >> > > I don't see any reasons to not backport these. > The first one fixes failure to online memory, why it shouldn't be fixed in -stable? > The second one is fixes boot crash, it's definitely stable material IMO. > Agreed, at least the second one should be cc stable, as I can reproduce it with a simple QEMU command. -- Thanks, David / dhildenb