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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 79963C433E0 for ; Thu, 21 Jan 2021 11:32:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 25A29238EC for ; Thu, 21 Jan 2021 11:32:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730412AbhAULbw (ORCPT ); Thu, 21 Jan 2021 06:31:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41874 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730087AbhAULas (ORCPT ); Thu, 21 Jan 2021 06:30:48 -0500 Received: from shrek.podlesie.net (shrek-3s.podlesie.net [IPv6:2a00:13a0:3010::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 00D15C061575; Thu, 21 Jan 2021 03:29:59 -0800 (PST) Received: by shrek.podlesie.net (Postfix, from userid 603) id 05D2A7BD; Thu, 21 Jan 2021 12:29:57 +0100 (CET) Date: Thu, 21 Jan 2021 12:29:57 +0100 From: Krzysztof Mazur To: Andy Lutomirski Cc: x86@kernel.org, LKML , Krzysztof =?iso-8859-2?Q?Ol=EAdzki?= , Arnd Bergmann , stable@vger.kernel.org Subject: Re: [PATCH v3 2/4] x86/mmx: Use KFPU_387 for MMX string operations Message-ID: <20210121112957.GA16586@shrek.podlesie.net> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.6.2 (2016-07-01) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 20, 2021 at 09:09:49PM -0800, Andy Lutomirski wrote: > The default kernel_fpu_begin() doesn't work on systems that support XMM but > haven't yet enabled CR4.OSFXSR. This causes crashes when _mmx_memcpy() is > called too early because LDMXCSR generates #UD when the aforementioned bit > is clear. > > Fix it by using kernel_fpu_begin_mask(KFPU_387) explicitly. > > Fixes: 7ad816762f9b ("x86/fpu: Reset MXCSR to default in kernel_fpu_begin()") > Cc: > Reported-by: Krzysztof Mazur > Signed-off-by: Andy Lutomirski > --- > arch/x86/lib/mmx_32.c | 20 +++++++++++++++----- > 1 file changed, 15 insertions(+), 5 deletions(-) Thanks, 5.10 + this patch series boots on K7 with SSE. Tested-by: Krzysztof Mazur Regards, Krzysiek