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=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_NEOMUTT 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 43B21C43381 for ; Thu, 14 Feb 2019 15:28:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1C7CA2229F for ; Thu, 14 Feb 2019 15:28:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2407580AbfBNP2T convert rfc822-to-8bit (ORCPT ); Thu, 14 Feb 2019 10:28:19 -0500 Received: from Galois.linutronix.de ([146.0.238.70]:50096 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726906AbfBNP2T (ORCPT ); Thu, 14 Feb 2019 10:28:19 -0500 Received: from bigeasy by Galois.linutronix.de with local (Exim 4.80) (envelope-from ) id 1guIvu-0002YR-Sj; Thu, 14 Feb 2019 16:28:15 +0100 Date: Thu, 14 Feb 2019 16:28:14 +0100 From: Sebastian Andrzej Siewior To: Borislav Petkov 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 15/22] x86/entry: Add TIF_NEED_FPU_LOAD Message-ID: <20190214152814.dptm4edcpfn7vrff@linutronix.de> References: <20190109114744.10936-1-bigeasy@linutronix.de> <20190109114744.10936-16-bigeasy@linutronix.de> <20190130115507.GE18383@zn.tnic> <20190207114941.jzydrry5xpjngyiv@linutronix.de> <20190213093553.GC9683@zn.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8BIT In-Reply-To: <20190213093553.GC9683@zn.tnic> User-Agent: NeoMutt/20180716 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019-02-13 10:35:53 [+0100], Borislav Petkov wrote: … > > + * > > + * If TIF_NEED_FPU_LOAD is cleared then CPU's FPU registers are holding the > > + * current content of current()'s FPU register state. > > "current content of current" - that's a lot of c... > > Make that > > "... then the CPU's FPU registers are mirrored in the current thread's > FPU registers state." Replaced `mirrored' with saved: + * If TIF_NEED_FPU_LOAD is cleared then the CPU's FPU registers are saved in + * the current thread's FPU registers state. + * If TIF_NEED_FPU_LOAD is set then CPU's FPU registers may not hold current()'s + * FPU registers. It is required to load the registers before returning to + * userland or using the content otherwise. Sebastian