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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 B28B6C47404 for ; Fri, 11 Oct 2019 18:17:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 90A2A20673 for ; Fri, 11 Oct 2019 18:17:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728792AbfJKSR1 (ORCPT ); Fri, 11 Oct 2019 14:17:27 -0400 Received: from foss.arm.com ([217.140.110.172]:39288 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728701AbfJKSR1 (ORCPT ); Fri, 11 Oct 2019 14:17:27 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9DF25142F; Fri, 11 Oct 2019 11:17:26 -0700 (PDT) Received: from [10.1.196.105] (eglon.cambridge.arm.com [10.1.196.105]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3BE8B3F703; Fri, 11 Oct 2019 11:17:24 -0700 (PDT) Subject: Re: [PATCH v6 02/17] arm64: hibernate: pass the allocated pgdp to ttbr0 To: Pavel Tatashin References: <20191004185234.31471-1-pasha.tatashin@soleen.com> <20191004185234.31471-3-pasha.tatashin@soleen.com> From: James Morse Cc: jmorris@namei.org, sashal@kernel.org, ebiederm@xmission.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, corbet@lwn.net, catalin.marinas@arm.com, will@kernel.org, linux-arm-kernel@lists.infradead.org, marc.zyngier@arm.com, vladimir.murzin@arm.com, matthias.bgg@gmail.com, bhsharma@redhat.com, linux-mm@kvack.org, mark.rutland@arm.com Message-ID: Date: Fri, 11 Oct 2019 19:17:22 +0100 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20191004185234.31471-3-pasha.tatashin@soleen.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Pavel, On 04/10/2019 19:52, Pavel Tatashin wrote: > ttbr0 should be set to the beginning of pgdp, however, currently > in create_safe_exec_page it is set to pgdp after pgd_offset_raw(), > which works by accident. > > Fixes: 0194e760f7d2 ("arm64: hibernate: avoid potential TLB conflict") (That was a 'break before make' fix, the affected code comes from: 82869ac57b5d (""arm64: kernel: Add support for hibernate/suspend-to-disk)) But, it works in all one circumstances its used: we know all the top bits will be zero. I agree its by accident and we should fix it. I don't think we should send it to stable. Please drop the fixes tag, with that: Reviewed-by: James Morse Thanks, James [0] https://lore.kernel.org/linux-arm-kernel/ddd81093-89fc-5146-0b33-ad3bd9a1c10c@arm.com/