From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-1465196-1518185153-2-11705615957511013106 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.001, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='org', MailFrom='org' X-Spam-charsets: plain='UTF-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1518185153; b=UjowfPm8lEIR/lMPCY+GahZ6oDj95YFAQfxr2mvs/7XHSWa FbLth2KVXR2OHzKqVlHCLgsyUW6JUIgvuMZMcCx1bW+mlqJUmiapDK5pCxrS7NVT pMgbbmmKz7PZpZqgsYPdqeKyO7pxiz1ePSn9btJXG3hflbhLtqRj60fAPQ76NV2s p9b8Ugv1UoVnVPUV0Vck5jb5pOfIPZSXCcbhpaWX8wCo3V+Pcn9VJJY1FWWEArfj ZAuyqveNF3Fzi4ip/sz8lqbJL7aiCUkw5hLFwIIbZc19g9bvZogbSfQZF/Hp61f6 5TJmNWLMl1wavNR2KqwtGCc1aTV70muU+Q1RYzA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-type:sender :list-id; s=arctest; t=1518185153; bh=kjtrU5i1/ZicKHxq/smXclSBWz kz1a7rI0CXrqf6+0c=; b=Qbmkt1R89TV/8ovodHvZBEFrjlXbHFpStwP+fjr7xe xzygxpoel0OTWh6E+e1g8u8JGVxAbDf34dbOmK555hNyNMjOVtDqYTcQQV3LtKpU 9OeqqYWRLnuYLegTpUvj1PUx7qo15QE7oPP54XAUG+bpFdzs7gtuq/CJ5h142Xvf Uvxj1mptJCXOaLi0KOLLww/pyv/yCfrB2FmXdtMDOHhDCk1o7+SSGcIfngslKVH2 yrMVn6+jdoSOV/1A/q9qb3KmjqoW8CliXs2Bku16ubHEUjoPq00qjqCa/qghYSEC hRPGFNqh18tRDTZsVSols+yYgJVL6Q1sZ6b/1qutyiXw== ARC-Authentication-Results: i=1; mx3.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes Authentication-Results: mx3.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752721AbeBINm6 (ORCPT ); Fri, 9 Feb 2018 08:42:58 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:50086 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753128AbeBINm5 (ORCPT ); Fri, 9 Feb 2018 08:42:57 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Linus Torvalds , Andi Kleen , Ingo Molnar , Dan Williams , Thomas Gleixner , linux-arch@vger.kernel.org, Tom Lendacky , Kees Cook , kernel-hardening@lists.openwall.com, Al Viro , alan@linux.intel.com, David Woodhouse Subject: [PATCH 4.9 59/92] x86: Introduce barrier_nospec Date: Fri, 9 Feb 2018 14:39:28 +0100 Message-Id: <20180209133935.497488184@linuxfoundation.org> X-Mailer: git-send-email 2.16.1 In-Reply-To: <20180209133931.211869118@linuxfoundation.org> References: <20180209133931.211869118@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dan Williams (cherry picked from commit b3d7ad85b80bbc404635dca80f5b129f6242bc7a) Rename the open coded form of this instruction sequence from rdtsc_ordered() into a generic barrier primitive, barrier_nospec(). One of the mitigations for Spectre variant1 vulnerabilities is to fence speculative execution after successfully validating a bounds check. I.e. force the result of a bounds check to resolve in the instruction pipeline to ensure speculative execution honors that result before potentially operating on out-of-bounds data. No functional changes. Suggested-by: Linus Torvalds Suggested-by: Andi Kleen Suggested-by: Ingo Molnar Signed-off-by: Dan Williams Signed-off-by: Thomas Gleixner Cc: linux-arch@vger.kernel.org Cc: Tom Lendacky Cc: Kees Cook Cc: kernel-hardening@lists.openwall.com Cc: gregkh@linuxfoundation.org Cc: Al Viro Cc: alan@linux.intel.com Link: https://lkml.kernel.org/r/151727415361.33451.9049453007262764675.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: David Woodhouse Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/barrier.h | 4 ++++ arch/x86/include/asm/msr.h | 3 +-- 2 files changed, 5 insertions(+), 2 deletions(-) --- a/arch/x86/include/asm/barrier.h +++ b/arch/x86/include/asm/barrier.h @@ -47,6 +47,10 @@ static inline unsigned long array_index_ /* Override the default implementation from linux/nospec.h. */ #define array_index_mask_nospec array_index_mask_nospec +/* Prevent speculative execution past this barrier. */ +#define barrier_nospec() alternative_2("", "mfence", X86_FEATURE_MFENCE_RDTSC, \ + "lfence", X86_FEATURE_LFENCE_RDTSC) + #ifdef CONFIG_X86_PPRO_FENCE #define dma_rmb() rmb() #else --- a/arch/x86/include/asm/msr.h +++ b/arch/x86/include/asm/msr.h @@ -188,8 +188,7 @@ static __always_inline unsigned long lon * that some other imaginary CPU is updating continuously with a * time stamp. */ - alternative_2("", "mfence", X86_FEATURE_MFENCE_RDTSC, - "lfence", X86_FEATURE_LFENCE_RDTSC); + barrier_nospec(); return rdtsc(); }