From mboxrd@z Thu Jan 1 00:00:00 1970 From: Baoquan He Subject: Re: [PATCH v8 0/3] x86/boot/KASLR: Parse ACPI table and limit kaslr in immovable memory Date: Wed, 10 Oct 2018 17:21:17 +0800 Message-ID: <20181010092117.GG25297@MiWiFi-R3L-srv> References: <20181010084119.17539-1-fanc.fnst@cn.fujitsu.com> <20181010085920.GB5533@zn.tnic> <20181010090620.GF25297@MiWiFi-R3L-srv> <20181010091205.GA10618@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20181010091205.GA10618@localhost.localdomain> Sender: linux-kernel-owner@vger.kernel.org To: Chao Fan Cc: Borislav Petkov , Ingo Molnar , Thomas Gleixner , linux-kernel@vger.kernel.org, x86@kernel.org, linux-efi@vger.kernel.org, linux-acpi@vger.kernel.org, mingo@redhat.com, hpa@zytor.com, keescook@chromium.org, rjw@rjwysocki.net, lenb@kernel.org, ard.biesheuvel@linaro.org, indou.takao@jp.fujitsu.com, caoj.fnst@cn.fujitsu.com, Masayoshi Mizuma List-Id: linux-acpi@vger.kernel.org On 10/10/18 at 05:12pm, Chao Fan wrote: > On Wed, Oct 10, 2018 at 05:06:20PM +0800, Baoquan He wrote: > >Hi Boris, > > > >On 10/10/18 at 10:59am, Borislav Petkov wrote: > >> ... and we just picked up > >> > >> https://lkml.kernel.org/r/20181001140843.26137-1-msys.mizuma@gmail.com > >> > >> and without having looked at the rest of your stuff, if people accept > >> your solution, we don't need the silly parameter anymore, right? > >> > >> Which means, we should not rush the whole thing yet until the whole > >> KASLR vs movable memory gets solved properly. > > > >Masa's patches solves the problem in memory region KASLR which later hot > >added memory may be big than the default padding 10 TB. > > > >Chao's patches is trying to fix a conflict between 'movable_node' and > >kernel text KASLR. If 'movable_node' specified, we rely on SRAT to get > >which memory region is movable or immovable, and movable region can be > >hot removed. But if kernel is randomized into movable memory, it can't > >be hot removed any more, this is a regression after KASLR introduced. > >So this is a different issue than Masa's. > > Yes, they are two issues. > But if we can get more memory information by the function in > the new file acpi.c, semms it's helfpul to Masa's issue. Hmm, reading SRAT three times during x86 kernel boot? Maybe we try this after the function has run a time and proved very stable? Thanks Baoquan