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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 C8170ECDFB8 for ; Mon, 23 Jul 2018 23:42:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8957320671 for ; Mon, 23 Jul 2018 23:42:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8957320671 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388272AbeGXAqP (ORCPT ); Mon, 23 Jul 2018 20:46:15 -0400 Received: from mga06.intel.com ([134.134.136.31]:5717 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388149AbeGXAqP (ORCPT ); Mon, 23 Jul 2018 20:46:15 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 23 Jul 2018 16:42:39 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,394,1526367600"; d="scan'208";a="58879199" Received: from mfwrenn-mobl1.amr.corp.intel.com (HELO tstruk-mobl1.jf.intel.com) ([10.252.131.18]) by orsmga007.jf.intel.com with ESMTP; 23 Jul 2018 16:42:38 -0700 Subject: Re: [PATCH] tpm: add support for partial reads To: Jason Gunthorpe Cc: James Bottomley , Jarkko Sakkinen , linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org References: <153201555276.20155.1352499992826895966.stgit@tstruk-mobl1.jf.intel.com> <20180723201956.GB26824@linux.intel.com> <1532380412.4112.22.camel@HansenPartnership.com> <7441b5ef-18d8-13aa-ef4d-40fe684c9218@intel.com> <20180723215620.GH532@ziepe.ca> <20180723220822.GJ532@ziepe.ca> From: Tadeusz Struk Openpgp: preference=signencrypt Autocrypt: addr=tadeusz.struk@intel.com; prefer-encrypt=mutual; keydata= xsDiBEiLICMRBADteQacQxypsuFvAw6IwYzbD8pgQi+kLYBcqfGgVAUN/cO+sLl6u1lVdaDB fhAArdbV9lpoqcWnmhQFTb4A+W569EpydBr6nuatWkEB+fmmx8YoUtuZfXt7v+1l1rc09kaW LY+TkwQkvFCeuvdasgmBLnmRWymEGWi1E12hUgTw/wCgtK24geC7XkiuANMv0gpr+raOgQMD /2yJZ0SeXQApWyTRaeIYN8GgYHZTWuBp/ofN+viEkhrDxahcaGPP5B/Nv6VS1+M0e5m8OzHj qPUbgfyOeJcslC5aoZdqqqzVWVLaA/+Jy+O+6T3k3R/IryVVATldBlwnGFDhET0mKQsd15zt cIdQBBbfSFR5VlugZuWV5q442IpPA/4g7nen9FFPxh45Te8D54hAsOCywjm6xUE0UJGYHeJ/ MXCPtuXfVCbYcOxZVH7kUS2Vtk5d3bF40IE2WnVq1ZScNANF4ZjikxYhYGfNWX3HXak1gSoj UrY87rMSjPIAry4L0BoIx2qgL/k4iV/3QcXL4t5wosU0iw++suf1zGGcKM0gVGFkZXVzeiBT dHJ1ayA8dHN0cnVrQGdtYWlsLmNvbT7CYwQTEQIAIwIbAwYLCQgHAwIEFQIIAwQWAgMBAh4B AheABQJQTjJTAhkBAAoJEDFswfskq9xyqvcAoI2nsaUCX8ZGbu+Jhq+++qlBFJ2rAJ983RoO R2ofHhn3g3Qi4K34tw0l087BTQRauzUlARAAqkWRL/InEPnoGMg/gw/CRaDBaIBgMsvIcghI 7xevIzpleXt6jKHghSBooH+zaT7qi4u2gkgPn4odsER3Rm94XgrZJgoqls6EpKMWpJNGP4HT eYgykhfsZOLX8ijUbjTM/Sm/dZVo6aYoBL2+ciJwyl+Zt3Mp6un3/GWu6cA9005V50pRqO7j PTlVCHi2bedcEEf5DDsYJv/3Oz8/4LpSf6BL6BltjeZVa2y03dTMmD031JTH+OuyJm1yh72Z HWxhlYNXOv6uFJJVr+paQjrAsBVIYKhK24bD+uGJxLm8AN9i7/Si+2YeSsXvKUhk9mIoFBnU VFo63cziRTcpRu/kXgDAbujwN88qytEcvhEZHS6B9vdws+lhTpolEjkLCkz0Y59z4Fs9srKy QkRN+wtdiLgrwyDW3ryAKxcDmOumGWebDxpaOI/pBhrlS93HmDlvj7JmgTUU4a/NhwI3dXh5 pn8FZzZyVXe3Kc3bu5T3UAC7uztinsAvCJQS6jGZWrXmXkqYkaLXQOw61eInWjr01zE/zDbE mdJPM0+va/gtZx9TtGxr4PpjbqswqCiubLDZXZHh5uqArPv/i+E8aXIsNSTN6Rrqs1j9YgDN ALksibv6+tXH3sOlCUgjuZgJH3+s/mnaAtiV2rZ/WlH15d6nd0uiDSZrKhlR+g4NHMh1ztEA EQEAAcJPBBgRAgAPBQJauzUlAhsMBQkJZgGAAAoJEDFswfskq9xyfv8AoI8aPrJCoM0h5WOP kKxMmPEPHzUNAJ9jBBYXhX1CWg+IhI7i/fLlI0vwCA== Message-ID: Date: Mon, 23 Jul 2018 16:42:38 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20180723220822.GJ532@ziepe.ca> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/23/2018 03:08 PM, Jason Gunthorpe wrote: > On Mon, Jul 23, 2018 at 03:00:20PM -0700, Tadeusz Struk wrote: >> On 07/23/2018 02:56 PM, Jason Gunthorpe wrote: >>> The proposed patch doesn't clear the data_pending if the entire buffer >>> is not consumed, so of course it is ABI breaking, that really isn't OK. >> The data_pending will be cleared by the timeout handler if the user doesn't >> read the response fully before the timeout expires. The is the same situation >> if the user would not read the response at all. > That causes write() to fail with EBUSY > > NAK from me on breaking the ABI like this What if we introduce this new behavior only for the non-blocking mode as James suggested? Or do you have some other suggestions? Thanks, -- Tadeusz