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=-3.9 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 6DCE2C4346E for ; Sun, 27 Sep 2020 23:44:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3FC5923A33 for ; Sun, 27 Sep 2020 23:44:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726421AbgI0Xog (ORCPT ); Sun, 27 Sep 2020 19:44:36 -0400 Received: from mga07.intel.com ([134.134.136.100]:49228 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726392AbgI0Xof (ORCPT ); Sun, 27 Sep 2020 19:44:35 -0400 IronPort-SDR: myz93UbUXq+313TweIkD60PEEJc1x4J3hTjFAzlJvwRnE1cx9SiUI8VOwbMJ9kTZTNf0qOZZPk sYeRtxFWKgsw== X-IronPort-AV: E=McAfee;i="6000,8403,9757"; a="226066131" X-IronPort-AV: E=Sophos;i="5.77,311,1596524400"; d="scan'208";a="226066131" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Sep 2020 16:44:34 -0700 IronPort-SDR: p/MoEwnZUTIU6YADym/9tny3NBWILcdmUcBVG/1LvGtme765bN2LwleFvXBR+JX1SFCFJi8nh0 Tbob45FrVRsw== X-IronPort-AV: E=Sophos;i="5.77,311,1596524400"; d="scan'208";a="488337532" Received: from memara-mobl.ger.corp.intel.com (HELO localhost) ([10.252.49.157]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Sep 2020 16:44:32 -0700 Date: Mon, 28 Sep 2020 02:44:34 +0300 From: Jarkko Sakkinen To: Jason Gunthorpe , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras Cc: Ard Biesheuvel , linux-integrity , Linux Kernel Mailing List , Peter Huewe , linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH] tpm: of: avoid __va() translation for event log address Message-ID: <20200927234434.GA5283@linux.intel.com> References: <20200922094128.26245-1-ardb@kernel.org> <20200925055626.GC165011@linux.intel.com> <20200925102920.GA180915@linux.intel.com> <20200925120018.GH9916@ziepe.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200925120018.GH9916@ziepe.ca> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org On Fri, Sep 25, 2020 at 09:00:18AM -0300, Jason Gunthorpe wrote: > On Fri, Sep 25, 2020 at 01:29:20PM +0300, Jarkko Sakkinen wrote: > > On Fri, Sep 25, 2020 at 09:00:56AM +0200, Ard Biesheuvel wrote: > > > On Fri, 25 Sep 2020 at 07:56, Jarkko Sakkinen > > > wrote: > > > > > > > > On Tue, Sep 22, 2020 at 11:41:28AM +0200, Ard Biesheuvel wrote: > > > > > The TPM event log is provided to the OS by the firmware, by loading > > > > > it into an area in memory and passing the physical address via a node > > > > > in the device tree. > > > > > > > > > > Currently, we use __va() to access the memory via the kernel's linear > > > > > map: however, it is not guaranteed that the linear map covers this > > > > > particular address, as we may be running under HIGHMEM on a 32-bit > > > > > architecture, or running firmware that uses a memory type for the > > > > > event log that is omitted from the linear map (such as EfiReserved). > > > > > > > > Makes perfect sense to the level that I wonder if this should have a > > > > fixes tag and/or needs to be backported to the stable kernels? > > > > > > > > > > AIUI, the code was written specifically for ppc64, which is a > > > non-highmem, non-EFI architecture. However, when we start reusing this > > > driver for ARM, this issue could pop up. > > > > > > The code itself has been refactored a couple of times, so I think it > > > will require different versions of the patch for different generations > > > of stable kernels. > > > > > > So perhaps just add Cc: , and wait and see how > > > far back it applies cleanly? > > > > Yeah, I think I'll cc it with some note before the diffstat. > > > > I'm thinking to cap it to only 5.x kernels (at least first) unless it is > > dead easy to backport below that. > > I have this vauge recollection of pointing at this before and being > told that it had to be __va for some PPC reason? > > Do check with the PPC people first, I see none on the CC list. > > Jason Thanks, added arch/powerpc maintainers. /Jarkko