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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 23643C282CC for ; Tue, 5 Feb 2019 01:13:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EBD732087C for ; Tue, 5 Feb 2019 01:13:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728201AbfBEBNm (ORCPT ); Mon, 4 Feb 2019 20:13:42 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:40552 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726086AbfBEBNm (ORCPT ); Mon, 4 Feb 2019 20:13:42 -0500 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1gqpIj-0004KP-OM; Tue, 05 Feb 2019 01:13:25 +0000 Received: from ben by deadeye with local (Exim 4.92-RC4) (envelope-from ) id 1gqpIj-0007sn-Ia; Tue, 05 Feb 2019 01:13:25 +0000 Message-ID: Subject: Re: [PATCH 3.16 045/305] x86/speculation: Apply IBPB more strictly to avoid cross-process data leak From: Ben Hutchings To: Andi Kleen , Jiri Kosina Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, akpm@linux-foundation.org, Denis Kirjanov , WoodhouseDavid , Josh Poimboeuf , SchauflerCasey , Andrea Arcangeli , Thomas Gleixner , Peter Zijlstra Date: Tue, 05 Feb 2019 01:13:25 +0000 In-Reply-To: <20190203213706.GA31598@tassilo.jf.intel.com> References: <20190203213706.GA31598@tassilo.jf.intel.com> Content-Type: multipart/signed; micalg="pgp-sha512"; protocol="application/pgp-signature"; boundary="=-WMooIOmOPocK8pn2Kg1f" User-Agent: Evolution 3.30.3-1 Mime-Version: 1.0 X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-WMooIOmOPocK8pn2Kg1f Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Sun, 2019-02-03 at 13:37 -0800, Andi Kleen wrote: > On Sun, Feb 03, 2019 at 08:05:53PM +0100, Jiri Kosina wrote: > > On Sun, 3 Feb 2019, Ben Hutchings wrote: > >=20 > > > 3.16.63-rc1 review patch. If anyone has any objections, please let m= e know. > > >=20 > > > ------------------ > > >=20 > > > From: Jiri Kosina > > >=20 > > > commit dbfe2953f63c640463c630746cd5d9de8b2f63ae upstream. > >=20 > > You really want the whole IBPB+STIBP revamp from upstream, otherwise= =20 > > you're going to get noticeable performance penalties on some workloads= =20 > > with some microcodes. >=20 > Yes, we would need the opt-in/opt-out support too. >=20 > Please don't merge it just as is. Thanks, I've now dropped this. Ben. --=20 Ben Hutchings It is impossible to make anything foolproof because fools are so ingenious. --=-WMooIOmOPocK8pn2Kg1f Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEErCspvTSmr92z9o8157/I7JWGEQkFAlxY4zUACgkQ57/I7JWG EQmhvg/9Gfwymq92ZBeqXTWrOOWyP/eGboeVWDAKE7bd2ZMPrtG4W2zVCXKhsweN 5fe9S+B3K8mixPOaSqC7Hl7JH1KLXzYuNatlbkr7pQTLjs07UTncoTMdrtNUe9m+ cMi8WPle0wogIqZq55qVCOArL9zoXgGObbgOwSKdRPP/QdwV2xm2NrM1YFiX+oCN 2k/cF32FN95pYWCQ7Zo+SOj9NcEAfjTu7UvFhlXLVVgKTZz3irsihzzMdEDnxqKt VYlUmj+mUBGZCJ7BuF2KEOhFdKRBO88zLwSMNLhob/HtcQ1zdKekfYUXMc9CJtUd 8iWap96dWozPT70rQF05EnXw6wGNOl2UE4YMskJxd25iCFDBaf1w49SHa/BERC9g fLiqvBDmEgV2p6ocB3RR7EyvtnU3XuCVIApJgn6YPnAsPu6DjgkVu4pXU9iWF2VM l36pdGw4Fcdkxdr1MxwYVDlLVej3GFpW3ZFosPVCB+52lhR7JyDYYLsxUM0FQiwP XA+w0q5xfqAJ+PYFHdOMI060DDhN+lNeUy0hdnmy8V9H2qiRlWHv1kNlrsu7+eSV QorhNcNGilgD6f49NoKMXN7PfZjyIXN+fFX1WOb/Qd0hKj3h3sKFZIl8iRtaDjVA 9YCRasw8+s4qjniGstgjPOF73rchMhSqY+9PGz4/sZ8aMKeOrws= =pKqg -----END PGP SIGNATURE----- --=-WMooIOmOPocK8pn2Kg1f--