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=-4.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_PASS autolearn=unavailable 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 E7FA1C169C4 for ; Mon, 11 Feb 2019 18:45:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B6CBB21B68 for ; Mon, 11 Feb 2019 18:45:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="FS09PW47" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732987AbfBKSpc (ORCPT ); Mon, 11 Feb 2019 13:45:32 -0500 Received: from mail-pl1-f194.google.com ([209.85.214.194]:45488 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727485AbfBKSpb (ORCPT ); Mon, 11 Feb 2019 13:45:31 -0500 Received: by mail-pl1-f194.google.com with SMTP id r14so693567pls.12; Mon, 11 Feb 2019 10:45:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=f8WuludV5DY6JBEAA4mWS3Heq1YO9mHamIhfdA1NQEs=; b=FS09PW47SWT9WTic+WSr4mCH38g+qNcP9wITmHqh1HKcG+6ItutSVxZ8RMdu72vk9u uacrON/m559Ip5F4/g42Q7TtJRX4SUXct6JDayEzbbp9MC05ZnjzwDXO0d6AGhCaPxUp Lbp2sJtNUojU89w+NaA/PmtJKM5Benzz8PNTwdQK/yj65Li4BG/GPWHFvXtKTXacrogd lGk7EmAQaVOiIHfOSP5SSFJ9e2daLCSxRgjarO/CX35uAs8kC8/IAzkZ7iXafrtdqnhs g3T2+zg3Sx/JiCCDEUC9EATv3oa4LFwhcIKi/oHQCFW48J8GUel/2fG2eWr2d3TPLVp8 R0Kg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=f8WuludV5DY6JBEAA4mWS3Heq1YO9mHamIhfdA1NQEs=; b=OrCxok5EIx5V/ndD/IFGtaEKSW0ctN3X5baSUEG5pjnhOZSlt/aYqCc3pccXkgXt91 OiC6Wyntf7Eqp0qParPN+Hl0IZ5EMxLfLlfcdViOaofnAKBPdKsMggnHmCcELStB+UHC qBCpSFXuWWF+3phgiywHsyoCsF2siPDZgvjnguCgmKhoCNy1kHxtYpN9vjb6xs5dpjsO kDnpFLyUtyM0XcZfO71jiz2+2q1ja0kL9NoNsPlQB+SEu+Cnxklr+SOb4KWFHkgbWPGK GYmMV8QDs/LdvggWBYlr5psiJNs/CP+8F7R3TQQ00qpSTL3p/x7SSRlbmYVAb38bdDaD gOWQ== X-Gm-Message-State: AHQUAubDzzLEpbTjwmsEqhUu+PLVX4xAfe3o+6hdx3v14y9TYirkRGn0 7PKeOI+BokCzR0lLxHxpR+k= X-Google-Smtp-Source: AHgI3IYkqqWg3qLv11mJkantOVmSlD1yu0ktdetixdx7d8k099+SMnCkUVzvna814b0ufrtSyUZubQ== X-Received: by 2002:a17:902:7148:: with SMTP id u8mr11197355plm.110.1549910730206; Mon, 11 Feb 2019 10:45:30 -0800 (PST) Received: from [10.33.115.182] ([66.170.99.1]) by smtp.gmail.com with ESMTPSA id e65sm16254804pfc.184.2019.02.11.10.45.28 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Feb 2019 10:45:29 -0800 (PST) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 12.2 \(3445.102.3\)) Subject: Re: [PATCH v2 10/20] x86: avoid W^X being broken during modules loading From: Nadav Amit In-Reply-To: <20190211182956.GN19618@zn.tnic> Date: Mon, 11 Feb 2019 10:45:26 -0800 Cc: Rick Edgecombe , Andy Lutomirski , Ingo Molnar , LKML , X86 ML , "H. Peter Anvin" , Thomas Gleixner , Dave Hansen , Peter Zijlstra , Damian Tometzki , linux-integrity , LSM List , Andrew Morton , Kernel Hardening , Linux-MM , Will Deacon , Ard Biesheuvel , Kristen Carlson Accardi , "Dock, Deneen T" , Kees Cook , Dave Hansen , Masami Hiramatsu Content-Transfer-Encoding: 7bit Message-Id: <1533F2BB-2284-499B-9912-6D74D0B87BC1@gmail.com> References: <20190129003422.9328-1-rick.p.edgecombe@intel.com> <20190129003422.9328-11-rick.p.edgecombe@intel.com> <20190211182956.GN19618@zn.tnic> To: Borislav Petkov X-Mailer: Apple Mail (2.3445.102.3) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On Feb 11, 2019, at 10:29 AM, Borislav Petkov wrote: > >> diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c >> index 76d482a2b716..69f3e650ada8 100644 >> --- a/arch/x86/kernel/alternative.c >> +++ b/arch/x86/kernel/alternative.c >> @@ -667,15 +667,29 @@ void __init alternative_instructions(void) >> * handlers seeing an inconsistent instruction while you patch. >> */ >> void *__init_or_module text_poke_early(void *addr, const void *opcode, >> - size_t len) >> + size_t len) >> { >> unsigned long flags; >> - local_irq_save(flags); >> - memcpy(addr, opcode, len); >> - local_irq_restore(flags); >> - sync_core(); >> - /* Could also do a CLFLUSH here to speed up CPU recovery; but >> - that causes hangs on some VIA CPUs. */ >> + >> + if (static_cpu_has(X86_FEATURE_NX) && > > Not a fast path - boot_cpu_has() is fine here. Are you sure about that? This path is still used when modules are loaded.