From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5FF44C433ED for ; Mon, 19 Apr 2021 04:05:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4231660E09 for ; Mon, 19 Apr 2021 04:05:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237530AbhDSEF2 (ORCPT ); Mon, 19 Apr 2021 00:05:28 -0400 Received: from bilbo.ozlabs.org ([203.11.71.1]:54461 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229473AbhDSEEs (ORCPT ); Mon, 19 Apr 2021 00:04:48 -0400 Received: by ozlabs.org (Postfix, from userid 1034) id 4FNtVT5PRGz9vGv; Mon, 19 Apr 2021 14:04:17 +1000 (AEST) From: Michael Ellerman To: Dmitry Safonov , linux-kernel@vger.kernel.org Cc: Paul Mackerras , Dmitry Safonov <0x7f454c46@gmail.com>, linuxppc-dev@lists.ozlabs.org, Laurent Dufour , stable@vger.kernel.org, Andy Lutomirski , Andrei Vagin In-Reply-To: <20210326191720.138155-1-dima@arista.com> References: <20210326191720.138155-1-dima@arista.com> Subject: Re: [PATCH] powerpc/vdso: Separate vvar vma from vdso Message-Id: <161880478605.1398509.2763333717274966533.b4-ty@ellerman.id.au> Date: Mon, 19 Apr 2021 13:59:46 +1000 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 26 Mar 2021 19:17:20 +0000, Dmitry Safonov wrote: > Since commit 511157ab641e ("powerpc/vdso: Move vdso datapage up front") > VVAR page is in front of the VDSO area. In result it breaks CRIU > (Checkpoint Restore In Userspace) [1], where CRIU expects that "[vdso]" > from /proc/../maps points at ELF/vdso image, rather than at VVAR data page. > Laurent made a patch to keep CRIU working (by reading aux vector). > But I think it still makes sence to separate two mappings into different > VMAs. It will also make ppc64 less "special" for userspace and as > a side-bonus will make VVAR page un-writable by debugger (which previously > would COW page and can be unexpected). > > [...] Applied to powerpc/next. [1/1] powerpc/vdso: Separate vvar vma from vdso https://git.kernel.org/powerpc/c/1c4bce6753857dc409a0197342d18764e7f4b741 cheers