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 E97C4C64EBC for ; Thu, 4 Oct 2018 16:45:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A96492098A for ; Thu, 4 Oct 2018 16:45:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A96492098A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=surriel.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 S1728092AbeJDXjP (ORCPT ); Thu, 4 Oct 2018 19:39:15 -0400 Received: from shelob.surriel.com ([96.67.55.147]:56326 "EHLO shelob.surriel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727415AbeJDXjP (ORCPT ); Thu, 4 Oct 2018 19:39:15 -0400 Received: from imladris.surriel.com ([96.67.55.152]) by shelob.surriel.com with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1g86kO-0003AV-F2; Thu, 04 Oct 2018 12:45:08 -0400 Message-ID: <8ea44ae2bb4844df812ea4c6cb0c00ef12708c51.camel@surriel.com> Subject: Re: [PATCH 00/11 v3] x86: load FPU registers on return to userland From: Rik van Riel To: Sebastian Andrzej Siewior , linux-kernel@vger.kernel.org Cc: x86@kernel.org, Andy Lutomirski , Paolo Bonzini , Radim =?UTF-8?Q?Kr=C4=8Dm=C3=A1=C5=99?= , kvm@vger.kernel.org, "Jason A. Donenfeld" , Dave Hansen Date: Thu, 04 Oct 2018 12:45:08 -0400 In-Reply-To: <20181004140547.13014-1-bigeasy@linutronix.de> References: <20181004140547.13014-1-bigeasy@linutronix.de> Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-CCYwfcJr17T/u8twOaRy" X-Mailer: Evolution 3.28.5 (3.28.5-1.fc28) Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-CCYwfcJr17T/u8twOaRy Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Thu, 2018-10-04 at 16:05 +0200, Sebastian Andrzej Siewior wrote: > In v3 I dropped that decouple idea. I also learned that the wrpkru > instruction is not privileged and so caching it in kernel does not > work. Wait, so any thread can bypass its memory protection keys, even if there is a seccomp filter preventing it from calling the PKRU syscalls? Is that intended? Is that simply a hardware limitation, or something where we can set a flag somewhere to force tasks to go through the kernel? --=20 All Rights Reversed. --=-CCYwfcJr17T/u8twOaRy Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEEKR73pCCtJ5Xj3yADznnekoTE3oMFAlu2Q5QACgkQznnekoTE 3oPwNwf/Zv/OpILcyjCSA6nTBdg+SHTgfDg/BUMtLnZZUzR09a6Wm5sD2keAzM5F qFfC+ladBxbir0jRg/Y1lOFU3pUbiF9EUcVwS0Q1Umu8mqYSrdJ97Jh1U/waWQIa Da2ommOp50I1rtWIF1ej30blt4c9IuDYiscYSO8sXAgu9DCWE0tK/wru2IaVqaFP U9ibaSo0VO6J4x/ryqB54ic3tJvS0lJsJj7o4VLHreuwkLpJbhDzmyYchCidqO7J OkuDh6WBPOZgGZX+DUmfl4lu5xyNqUq8k9GWoHvc0giAQC8xLgUutIIsw7rCn6TO ecCMifRIthNeiHfsCYnD0W9wHq8i0Q== =C+9y -----END PGP SIGNATURE----- --=-CCYwfcJr17T/u8twOaRy--