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=-0.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 65D1DC433DF for ; Thu, 14 May 2020 14:08:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 42ACE2070A for ; Thu, 14 May 2020 14:08:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728000AbgENOIs (ORCPT ); Thu, 14 May 2020 10:08:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60344 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727922AbgENOIa (ORCPT ); Thu, 14 May 2020 10:08:30 -0400 Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 36F58C061A0C for ; Thu, 14 May 2020 07:08:30 -0700 (PDT) Received: from p5de0bf0b.dip0.t-ipconnect.de ([93.224.191.11] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1jZEWr-0008Ob-Nu; Thu, 14 May 2020 16:08:05 +0200 Received: by nanos.tec.linutronix.de (Postfix, from userid 1000) id DAAF71004CE; Thu, 14 May 2020 16:08:04 +0200 (CEST) From: Thomas Gleixner To: Mathieu Desnoyers , Andy Lutomirski Cc: linux-kernel , x86 , paulmck , Alexandre Chartre , Frederic Weisbecker , Paolo Bonzini , Sean Christopherson , Masami Hiramatsu , Petr Mladek , rostedt , "Joel Fernandes\, Google" , Boris Ostrovsky , Juergen Gross , Brian Gerst , Josh Poimboeuf , Will Deacon Subject: Re: [patch V4 part 3 09/29] x86/entry/32: Provide macro to emit IDT entry stubs In-Reply-To: <1225010168.20900.1589463536204.JavaMail.zimbra@efficios.com> References: <20200505134354.774943181@linutronix.de> <20200505134904.166735365@linutronix.de> <835459920.20630.1589420674977.JavaMail.zimbra@efficios.com> <1225010168.20900.1589463536204.JavaMail.zimbra@efficios.com> Date: Thu, 14 May 2020 16:08:04 +0200 Message-ID: <87eermzk1n.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Mathieu Desnoyers writes: > ----- On May 14, 2020, at 12:31 AM, Andy Lutomirski luto@kernel.org wrote: >> On Wed, May 13, 2020 at 6:44 PM Mathieu Desnoyers >> wrote: >> They're needed for all entries except SYSCALL, but they're hidden >> inside helpers in many cases. > > Indeed, on x86-32 the macro SAVE_ALL contains cld. That architecture > appears to be OK. > > What I am concerned about is the idtentry, idtentry_mce_db, > and idtentry_df macros introduced in entry_64.S by this series. > Those are supposed to be technically equivalent to the prior > code, which indeed has the ASM_CLAC but no "cld". > > So maybe the cld happens to be hidden elsewhere, but I'm clearly > missing it ? Or is it not needed for some reason ? It's needed and it is there where it was forever in error_entry and paranoid_entry. It probably makes sense to stick it right after the CLAC. Thanks, tglx