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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT 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 B85F5C46465 for ; Thu, 8 Nov 2018 11:38:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8A24E2089F for ; Thu, 8 Nov 2018 11:38:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8A24E2089F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=alien8.de 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 S1727404AbeKHVNa (ORCPT ); Thu, 8 Nov 2018 16:13:30 -0500 Received: from mail.skyhub.de ([5.9.137.197]:54858 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726274AbeKHVNa (ORCPT ); Thu, 8 Nov 2018 16:13:30 -0500 X-Virus-Scanned: Nedap ESD1 at mail.skyhub.de Received: from mail.skyhub.de ([127.0.0.1]) by localhost (blast.alien8.de [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id 0AFgzeYoO3yh; Thu, 8 Nov 2018 12:38:24 +0100 (CET) Received: from zn.tnic (p200300EC2BD03D00329C23FFFEA6A903.dip0.t-ipconnect.de [IPv6:2003:ec:2bd0:3d00:329c:23ff:fea6:a903]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 797FC1EC0402; Thu, 8 Nov 2018 12:38:24 +0100 (CET) Date: Thu, 8 Nov 2018 12:38:17 +0100 From: Borislav Petkov To: Sebastian Andrzej Siewior Cc: linux-kernel@vger.kernel.org, x86@kernel.org, Andy Lutomirski , Paolo Bonzini , Radim =?utf-8?B?S3LEjW3DocWZ?= , kvm@vger.kernel.org, "Jason A. Donenfeld" , Rik van Riel , Dave Hansen Subject: Re: [PATCH 01/23] x86/fpu: Use ULL for shift in xfeature_uncompacted_offset() Message-ID: <20181108113817.GB7543@zn.tnic> References: <20181107194858.9380-1-bigeasy@linutronix.de> <20181107194858.9380-2-bigeasy@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20181107194858.9380-2-bigeasy@linutronix.de> 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 On Wed, Nov 07, 2018 at 08:48:36PM +0100, Sebastian Andrzej Siewior wrote: > The xfeature mask is 64bit so a shift from a number to its mask should > have LL prefix or else nr > 31 will be lost. This is not a problem now > but should XFEATURE_MASK_SUPERVISOR gain a bit >31 then this check won't > catch it. > > Add a ULL suffix so >31bit number will be properly shifted. > > Signed-off-by: Sebastian Andrzej Siewior > --- > arch/x86/kernel/fpu/xstate.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c > index 87a57b7642d36..9dc0a2c8c2755 100644 > --- a/arch/x86/kernel/fpu/xstate.c > +++ b/arch/x86/kernel/fpu/xstate.c > @@ -444,7 +444,7 @@ static int xfeature_uncompacted_offset(int xfeature_nr) > * format. Checking a supervisor state's uncompacted offset is > * an error. > */ > - if (XFEATURE_MASK_SUPERVISOR & (1 << xfeature_nr)) { > + if (XFEATURE_MASK_SUPERVISOR & (1ULL << xfeature_nr)) { Or simply BIT_ULL(xfeature_nr). -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.