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,URIBL_BLOCKED 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 E885AC43143 for ; Tue, 2 Oct 2018 16:12:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 93CF520666 for ; Tue, 2 Oct 2018 16:12:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 93CF520666 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.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 S1729509AbeJBW4i (ORCPT ); Tue, 2 Oct 2018 18:56:38 -0400 Received: from mga14.intel.com ([192.55.52.115]:57700 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729438AbeJBW4i (ORCPT ); Tue, 2 Oct 2018 18:56:38 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 02 Oct 2018 09:12:31 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,332,1534834800"; d="scan'208";a="237892502" Received: from schen9-desk.jf.intel.com (HELO [10.54.74.144]) ([10.54.74.144]) by orsmga004.jf.intel.com with ESMTP; 02 Oct 2018 09:12:28 -0700 Subject: Re: [Patch v2 4/4] x86/speculation: Add prctl to control indirect branch speculation per process To: Ingo Molnar Cc: Jiri Kosina , Thomas Gleixner , Tom Lendacky , Ingo Molnar , Peter Zijlstra , Josh Poimboeuf , Andrea Arcangeli , David Woodhouse , Andi Kleen , Dave Hansen , Casey Schaufler , Asit Mallick , Arjan van de Ven , Jon Masters , linux-kernel@vger.kernel.org, x86@kernel.org References: <20181002093530.GC122128@gmail.com> From: Tim Chen Openpgp: preference=signencrypt Autocrypt: addr=tim.c.chen@linux.intel.com; prefer-encrypt=mutual; keydata= xsFNBE6ONugBEAC1c8laQ2QrezbYFetwrzD0v8rOqanj5X1jkySQr3hm/rqVcDJudcfdSMv0 BNCCjt2dofFxVfRL0G8eQR4qoSgzDGDzoFva3NjTJ/34TlK9MMouLY7X5x3sXdZtrV4zhKGv 3Rt2osfARdH3QDoTUHujhQxlcPk7cwjTXe4o3aHIFbcIBUmxhqPaz3AMfdCqbhd7uWe9MAZX 7M9vk6PboyO4PgZRAs5lWRoD4ZfROtSViX49KEkO7BDClacVsODITpiaWtZVDxkYUX/D9OxG AkxmqrCxZxxZHDQos1SnS08aKD0QITm/LWQtwx1y0P4GGMXRlIAQE4rK69BDvzSaLB45ppOw AO7kw8aR3eu/sW8p016dx34bUFFTwbILJFvazpvRImdjmZGcTcvRd8QgmhNV5INyGwtfA8sn L4V13aZNZA9eWd+iuB8qZfoFiyAeHNWzLX/Moi8hB7LxFuEGnvbxYByRS83jsxjH2Bd49bTi XOsAY/YyGj6gl8KkjSbKOkj0IRy28nLisFdGBvgeQrvaLaA06VexptmrLjp1Qtyesw6zIJeP oHUImJltjPjFvyfkuIPfVIB87kukpB78bhSRA5mC365LsLRl+nrX7SauEo8b7MX0qbW9pg0f wsiyCCK0ioTTm4IWL2wiDB7PeiJSsViBORNKoxA093B42BWFJQARAQABzTRUaW0gQ2hlbiAo d29yayByZWxhdGVkKSA8dGltLmMuY2hlbkBsaW51eC5pbnRlbC5jb20+wsF+BBMBAgAoAhsD BgsJCAcDAgYVCAIJCgsEFgIDAQIeAQIXgAUCWfPBPgUJDyfxUQAKCRCiZ7WKota4SReFEACa 5ruzJM/hXJguHJY8i95rxHfLOgE7QoDgsR2aK2C1BSu84StTcT9BMikndQ0em28mpd1zROCs FvJ8Dzpp923699FU7s70+bFG9zIWtAOLWt2QyIMYImILzKkzkyLZo2RTcLNdUWS5fkAtjspQ QPg29W+kcbX1NhB6WDdbvk2HNeZoDh4A5ucOzKjEPqbSFIbw2Wt3RUmXxezjH1NzZG3fMkEN cT7JezYhUxvi2PrJlD+mo26q2/PQmFgF49tneRJXmYyie5o2+ClfFVO9I6Rd1k7hS9uXQLg3 udpnDKobNYZ7/+O5+ucp0Y/MwzTfBYmtJ5fBjUTi2L1RMDJee8WqCNY1VU6cQ8MD4KstxUp2 bxlSRAYaDtNa1Omr61E7BA1Cc2E3cIt/O1mMfudWUjCND8qrAtEnugqKjk5tJJZzmzIKSHPY dCiJtOBQaVAYYchXF2hwOKhpFS43V4FdWLlM1CnFXsmbk48hGbiA8XHU85JBCXmG0i4qUlKn x2ilChvq4A102ahnlGbEmFaSwxuqR/5lhai6lOkwHXDFUT6jblaSs24L3MTn/vXtvwaLEEKh SPzNaj7yFvEhrJoLiZmDm0SZuPbQ+wrmPWUbzyf5te2Oq0JyrHTQJoQqn+CwGqwF/JaUq60f VuUD3T0icgsfljsOA4apyH7kyfxXGP0hOM7BTQROjjboARAAx+LxKhznLH0RFvuBEGTcntrC 3S0tpYmVsuWbdWr2ZL9VqZmXh6UWb0K7w7OpPNW1FiaWtVLnG1nuMmBJhE5jpYsi+yU8sbMA 5BEiQn2hUo0k5eww5/oiyNI9H7vql9h628JhYd9T1CcDMghTNOKfCPNGzQ8Js33cFnszqL4I N9jh+qdg5FnMHs/+oBNtlvNjD1dQdM6gm8WLhFttXNPn7nRUPuLQxTqbuoPgoTmxUxR3/M5A KDjntKEdYZziBYfQJkvfLJdnRZnuHvXhO2EU1/7bAhdz7nULZktw9j1Sp9zRYfKRnQdIvXXa jHkOn3N41n0zjoKV1J1KpAH3UcVfOmnTj+u6iVMW5dkxLo07CddJDaayXtCBSmmd90OG0Odx cq9VaIu/DOQJ8OZU3JORiuuq40jlFsF1fy7nZSvQFsJlSmHkb+cDMZDc1yk0ko65girmNjMF hsAdVYfVsqS1TJrnengBgbPgesYO5eY0Tm3+0pa07EkONsxnzyWJDn4fh/eA6IEUo2JrOrex O6cRBNv9dwrUfJbMgzFeKdoyq/Zwe9QmdStkFpoh9036iWsj6Nt58NhXP8WDHOfBg9o86z9O VMZMC2Q0r6pGm7L0yHmPiixrxWdW0dGKvTHu/DH/ORUrjBYYeMsCc4jWoUt4Xq49LX98KDGN dhkZDGwKnAUAEQEAAcLBZQQYAQIADwIbDAUCVEAL2AUJC1VvawAKCRCiZ7WKota4SWWrD/9L 4H3kHUR9qPTfSpwFBV0+PspkpMQmRQ9cQauIRXL+qIqCYfx48Jz/WZkq47COhY4d1tAvX4qv lviIoCwShAHhVkxD2rWFpa6Yang7cyPDjS6sNChsZ9aTAP0zX4LLHN8ub5LwCcU9JA4Avwdy NDSeeSeqNq9QOvVd2bDmyHxgVv4zRgLTNPH28hXAnDODy0wCJWg53PWvlp35XfWdIsC0ZAPK vgA1Bh+FYYKfT8Uzj8J/SYH+chmeYMt+8Y+FZa+NybivWJg6+UaJ2fCTuKCc7TgqLneBudox izWQMnBso0tHOT6+ju+L+ewPWc0OrJdKJeadrE2T1E949vMup5jG0lJLeSpBNmELODNL0xz6 Erjs/pwX7cYGKUbJfBaQcC9frPfpWfSqnK5X+12HFDxAxquXKC4ejBJOhbo3xx0sziiPTC3m 4LvLkEa9evQNtMvRcnWY5qIC4YdT5waC0stYNpyCiBXpYArKYCmlra3xpgAe0MRL94PHU4UW yxxdxRubFYna9LeNcWL7C0w2ngg1jd0tjRjLnimrOL8rSVUzwjNSQOV37tWTueTr40M/SfjU B6bifflZQpeSY8IpqzKqB0vvxo2xD0rU7JqUh7rW8U6rg2JEzVgYiHS4cf/vJMHuauHAjH7a ys7DYlLhlOVo3o0jOor4xuZPrWbSp4w51sLBZQQYAQIADwIbDAUCWfPBJQUJDyfxOAAKCRCi Z7WKota4SZKQD/wLu3j8kgATic+wF3ekngjwPcW3JhbQJeHxUZwsb9OgVMHumlrZHGoltKQu FfAhG/sOfuAh5f7QMzzA1M+2JD1Q6lr74vUHNBu+xBFMgZstE6hpkKmn0pNZ5JS3iZRVRLBx dWw63DYr0GM80vmbHjAhwxoF2PsO2/PkWTc68+pFyl3Dy0heZSJii81hkzh8FnF8CaMH0VXu MJoWyuYgnC058hHj0QqXvlNx9LzMtmrsskTmPvwqXTgG/dTEfTkQ4RfX3enrBy55cg9tMc88 BEQ/0/JV1bCDwyWXKRpz6FsHbICGQ4G9TTD4pS5QJ+oRQccMjfiDM3rFTcG1RYP2lHXjSm9c 0VnimpQBz3LarrdHJilmTHbAWf5KLmtWfYXHrlncnhnCtw2nfwBBdy8cQW4tUyniSVRLOwGm eJziyuPJ5SVVZcil2oN5/o7js7BYAeAV/WVF2Sk/blnXaaObIYIVqnDhV4N0oUz1KXq1Leem Uvjo5rljmmhOBdgl6D0scXCWICbuuWN9eW2fZl38hBSI3M0MX0jnV2e+0FY+76iNmKadpTDw gY3OaQAZ/UlJVI+pRV4JtRrajtpo9Vb38SBPXwp9moWmwVQyIdFUXjCTQARvxjRsUoPVu9oA SCd9W74oOgrqC1hadvVU867d07PlWksfYwCeYP4bs+4GSLzI1w== Message-ID: <20a42fd4-0026-c30e-1d82-4a345f6257cc@linux.intel.com> Date: Tue, 2 Oct 2018 09:12:28 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.1.0 MIME-Version: 1.0 In-Reply-To: <20181002093530.GC122128@gmail.com> 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 10/02/2018 02:35 AM, Ingo Molnar wrote: > > * Tim Chen wrote: > >> To migitgate possible app to app attack from branch target buffer poisoning, >> a new prctl is provided to control branch speculation for applications in >> user app. The following interfaces are provided: > > s/migitgate > /mitigate > >> >> prctl(PR_SET_SPECULATION_CTRL, PR_INDIR_BRANCH, PR_SPEC_DISABLE, 0, 0); >> - Disable branch target speculation to protect against app to app >> style attack using IBPB and STIBP >> >> prctl(PR_SET_SPECULATION_CTRL, PR_INDIR_BRANCH, PR_SPEC_ENABLE, 0, 0); >> - Allow branch target speculation, no mitigation for Spectre V2 >> >> prctl(PR_GET_SPECULATION_CTRL, PR_INDIR_BRANCH, 0, 0, 0) >> - Query the indirect branch speculation restriction on a process > > Well 'a process' is always 'the current process' in this case, right? Right. > >> - lite - only turn on mitigation for non-dumpable processes >> + lite - turn on mitigation for non-dumpable processes >> + or processes that has indirect branch restricted >> + via prctl's PR_SET_SPECULATION_CTRL option > > s/or processes that has indirect > /or processes that have been indirect > > ? > >> + /* >> + * If being set on non-current task, delay setting the CPU >> + * mitigation until it is next scheduled. >> + * Use speculative_store_bypass_update will update SPEC_CTRL MSR >> + */ >> + if (task == current && update) >> + speculative_store_bypass_update_current(); > > Did you mean: > > Call to speculative_store_bypass_update_current() will update SPEC_CTRL MSR Yes. > > ? > > >> - * For lite protection mode, we only protect the non-dumpable >> - * processes. >> + * For lite protection mode, we protect processes >> + * where the user explicitly disable indirect branch >> + * speculation or mark the process as non-dumpable. > > s/where the user explicitly disable > /where the user explicitly disables > > ? > > Thanks, > > Ingo > Thanks for the corrections. I'll update the patchset. Tim