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=-3.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 8DBB3C2D0F8 for ; Tue, 12 May 2020 22:23:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 724852492E for ; Tue, 12 May 2020 22:23:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731824AbgELWXl (ORCPT ); Tue, 12 May 2020 18:23:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55536 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1731726AbgELWXY (ORCPT ); Tue, 12 May 2020 18:23:24 -0400 Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 37FE9C061A0C for ; Tue, 12 May 2020 15:23:24 -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 1jYdI5-0004b5-8f; Wed, 13 May 2020 00:22:22 +0200 Received: from nanos.tec.linutronix.de (localhost [IPv6:::1]) by nanos.tec.linutronix.de (Postfix) with ESMTP id C04A21006A1; Wed, 13 May 2020 00:22:20 +0200 (CEST) Message-Id: <20200512213809.583980272@linutronix.de> User-Agent: quilt/0.65 Date: Tue, 12 May 2020 23:01:01 +0200 From: Thomas Gleixner To: LKML Cc: x86@kernel.org, "Paul E. McKenney" , Andy Lutomirski , Alexandre Chartre , Frederic Weisbecker , Paolo Bonzini , Sean Christopherson , Masami Hiramatsu , Petr Mladek , Steven Rostedt , Joel Fernandes , Boris Ostrovsky , Juergen Gross , Brian Gerst , Mathieu Desnoyers , Josh Poimboeuf , Will Deacon , Tom Lendacky , Wei Liu , Michael Kelley , Jason Chen CJ , Zhao Yakui , "Peter Zijlstra (Intel)" Subject: [patch V5 02/38] x86/entry/64: Use native swapgs in asm_native_load_gs_index() References: <20200512210059.056244513@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-transfer-encoding: 8-bit 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 When PARAVIRT_XXL is in use, then load_gs_index() uses xen_load_gs_index() and (asm_))native_load_gs_index() is unused. It's therefore pointless to use the paravirtualized SWAPGS implementation in asm_native_load_gs_index(). Switch it to a plain swapgs. Signed-off-by: Thomas Gleixner Cc: Juergen Gross --- arch/x86/entry/entry_64.S | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -1043,11 +1043,11 @@ idtentry simd_coprocessor_error do_simd */ SYM_FUNC_START(asm_native_load_gs_index) FRAME_BEGIN - SWAPGS + swapgs .Lgs_change: movl %edi, %gs 2: ALTERNATIVE "", "mfence", X86_BUG_SWAPGS_FENCE - SWAPGS + swapgs FRAME_END ret SYM_FUNC_END(asm_native_load_gs_index) @@ -1057,7 +1057,7 @@ EXPORT_SYMBOL(asm_native_load_gs_index) .section .fixup, "ax" /* running with kernelgs */ SYM_CODE_START_LOCAL_NOALIGN(.Lbad_gs) - SWAPGS /* switch back to user gs */ + swapgs /* switch back to user gs */ .macro ZAP_GS /* This can't be a string because the preprocessor needs to see it. */ movl $__USER_DS, %eax