Received: by 2002:ac0:a5a6:0:0:0:0:0 with SMTP id m35-v6csp3988148imm; Wed, 5 Sep 2018 08:59:52 -0700 (PDT) X-Google-Smtp-Source: ANB0VdYsjifEj6fL9eIwlw2kWSWdwQiu6E/ZFTOnb9FHkhIpU+U6HvPulX+OEELGlEeB2glh5E/l X-Received: by 2002:a17:902:7447:: with SMTP id e7-v6mr15258794plt.186.1536163192860; Wed, 05 Sep 2018 08:59:52 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1536163192; cv=none; d=google.com; s=arc-20160816; b=o+5mD/ZJRosqFYzjfMikbNNXalOPatxPelOwBJdl9Z+uHMSwsFl9SRzwschKsUpNx/ jykTj4c2TxkiAsJ6jy87U3YeI/vMVAQJRR/melrOePOvd/eocG4uLWe/RRpNYWb0C1z9 WArVqcGNTfqB1yi+ImZVLpogXPGr/P7DqOk1UpWaT2/Jf+AgvHY9EvNIcXBZRvvbUz54 /RQ6mXq7L2YrN/6EtrVeUD3L356Pc/WYg/oaeca0p8LYspmfGxn8XtIfZWi0hoosX3Qm 6byWTZRwZ+XJe6PYMeU1ea0ser4PbpUSSBSez5HZ5WkdfxjZ1YlQv0xsm0734eTfeB2q 8ZEA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date; bh=1oA1ryMZWoskCc4NvA2MDPiiGdsQUlODmZg37vI9/sE=; b=LHXfuj7RjZNiUFO0CDMoJuJTpx+oGt4qiyS+x/xXkG8dcHtdAwrmDQixE/igxDeu2r ufcFmxOg1GIOftW3AbLnoNF0ucmiTuqEyzJ7umJCHhB0CUjmgXpabrf1wfcKpYQxvy6+ +A4pVRK8f/rrUJZ5xmGW197/7OBuLIj24vFw10GgoueSnq8BHR5nw2MmqSLec/95aQOq Qy2u6XuseBiidOuOhko9vfKFASAD64gqUYQXoK+kIMNz7ZRYJaiKBfXyTM3XiYvp8HUR TTR0wGJtbCszeaRHdMYa1S14l8Hxp4opafYMMXNIt972Ck1ELcR0p2+vidKbMTRN9csB 9Kzw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id d4-v6si2205301pgl.147.2018.09.05.08.59.37; Wed, 05 Sep 2018 08:59:52 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727628AbeIEU3X (ORCPT + 99 others); Wed, 5 Sep 2018 16:29:23 -0400 Received: from mga02.intel.com ([134.134.136.20]:3185 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726487AbeIEU3X (ORCPT ); Wed, 5 Sep 2018 16:29:23 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Sep 2018 08:58:34 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,334,1531810800"; d="scan'208";a="83282404" Received: from tassilo.jf.intel.com (HELO tassilo.localdomain) ([10.7.201.126]) by fmsmga002.fm.intel.com with ESMTP; 05 Sep 2018 08:58:24 -0700 Received: by tassilo.localdomain (Postfix, from userid 1000) id DB8DA300B65; Wed, 5 Sep 2018 08:58:23 -0700 (PDT) Date: Wed, 5 Sep 2018 08:58:23 -0700 From: Andi Kleen To: Jiri Kosina Cc: Tim Chen , "Schaufler, Casey" , Thomas Gleixner , Ingo Molnar , Peter Zijlstra , Josh Poimboeuf , Andrea Arcangeli , "Woodhouse, David" , Oleg Nesterov , "linux-kernel@vger.kernel.org" , "x86@kernel.org" Subject: Re: [PATCH v3 1/3] ptrace: Provide ___ptrace_may_access() that can be applied on arbitrary tasks Message-ID: <20180905155823.GL27886@tassilo.jf.intel.com> References: <31436186-88da-324e-88a0-8fdca7bf60ac@linux.intel.com> <99FC4B6EFCEFD44486C35F4C281DC67321447094@ORSMSX107.amr.corp.intel.com> <3f24e8c8-eab8-66c2-9a8d-957e30cac809@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > So, after giving it a bit more thought, I still believe "I want spectre V2 > protection" vs. "I do not care about spectre V2 on my system > (=nospectre_v2)" are the sane options we should provide; so I'll respin v4 > of my patchset, including the ptrace check in switch_mm() (statically > patched out on !IBPB-capable systems), and we can then later see whether > the LSM implementation, once it exists, should be used instead. Please if you repost include plenty of performance numbers for multi threaded workloads. It's ridiculous to even discuss this without them. -Andi