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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 0ED1DC06508 for ; Tue, 2 Jul 2019 03:43:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D23C12173E for ; Tue, 2 Jul 2019 03:43:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562039012; bh=9xXXAaNVoQxMbnf7HOo9+uevM9EuW2CJWbh76Gnu18w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=KXqAlhC9cSjxrNf6MZAuS5WwOiorMnCx1+W24tu0xEvLW8t75N0BYI4/05Q3hG4Xh U4wCHs/Kaes5clEZCS5V8+XO3M+L0UADz7qvzf02iDjON8py9+F9m0tNz5Z/PtznwB jzrAviMNb8LG0uf658vNZ+7u4jrbIyoJ9qcwPq3A= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727087AbfGBDnb (ORCPT ); Mon, 1 Jul 2019 23:43:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:53586 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726967AbfGBDnZ (ORCPT ); Mon, 1 Jul 2019 23:43:25 -0400 Received: from localhost (c-67-180-165-146.hsd1.ca.comcast.net [67.180.165.146]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F39A521848; Tue, 2 Jul 2019 03:43:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562039005; bh=9xXXAaNVoQxMbnf7HOo9+uevM9EuW2CJWbh76Gnu18w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ue+Zsg+aHxkVlZDcResfbXU0BW6bW96I6vwIGPkWuc4UNCGY76NWHLJ8b9fdrpaWa Rkkb41xJx6UTpfeMrrOnffwCbmxAfKiN/NkYHHxFR1TAIhdwG5LygBDlJlCbZiFXk1 rgtHYIQY9ssrwNr1hj5Y+/zUOJif/EJslTivWX2s= From: Andy Lutomirski To: LKML Cc: x86@kernel.org, "Bae, Chang Seok" , Borislav Petkov , Peter Zijlstra , Andy Lutomirski Subject: [PATCH 2/3] x86/entry/64: Don't compile ignore_sysret if 32-bit emulation is enabled Date: Mon, 1 Jul 2019 20:43:20 -0700 Message-Id: <0f7dafa72fe7194689de5ee8cfe5d83509fabcf5.1562035429.git.luto@kernel.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It's only used if !CONFIG_IA32_EMULATION, so disable it in normal configs. This will save a few bytes of text and reduce confusion. Cc: "Bae, Chang Seok" Signed-off-by: Andy Lutomirski --- arch/x86/entry/entry_64.S | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 7f9f5119d6b1..54b1b0468b2b 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -1743,11 +1743,17 @@ nmi_restore: iretq END(nmi) +#ifndef CONFIG_IA32_EMULATION +/* + * This handles SYSCALL from 32-bit code. There is no way to program + * MSRs to fully disable 32-bit SYSCALL. + */ ENTRY(ignore_sysret) UNWIND_HINT_EMPTY mov $-ENOSYS, %eax sysret END(ignore_sysret) +#endif ENTRY(rewind_stack_do_exit) UNWIND_HINT_FUNC -- 2.21.0