From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-1465196-1518185420-2-11066492770534391385 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=1518185420; b=EinUxsrdj7GS+gtNBKHN9ZdlRWnj1fkK9qwwWq6oVO0R+Jz Z7IUo37lJ4xDZ6w8wJfhWdtm+MLlqI89XI3Dz0/iTmlp9VGjypiw3zrrWUhGQcGN 7eHTgOVTutleQxJQ7+JiJQOhXwY5fN17IwXakwW/TukomWi++fQB/SceB2Oz6DD/ U1rg/1S/4FemWnYC/aC40cqG3Nbn18rgLDsnMFcx9vD8cNpZJtuSoTKIOerjbn6M 5DS9yBJbCUYwysXypOSZFBwmckD2ZZBQdUCUCtuCjp5/kNLiWkgfgv6HrQDV+4uH QXyIPO4ypkv9bODfA/t+FhLjqRG0ws8Pk40sOmA== 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=1518185420; bh=24pVcP+X0bTcsFthuFt9lhOU4d U5hkQUAF7uWMxMC8Q=; b=OH/QcwYwGyRQoREgimww/D9Wx2pvjJLgDb+2BjAgdp N3AiWftN2t01AADyRQ8pLc6XgX1M0eTwJYwxQskAb20h1aUxyBGdgpEDEHrvHrJ7 w9MCQw6V6tuRvwtqMH3rWOtReGNyH+RQ5c4MnMxaHrQmUE2WrRKIZOGFlUQNFAm9 Meh4ytBxMSpDf+eFevUyZMoG7AsjXkdb9duVzWdwuIkR0sS3A8m/4V03RF2ax9H3 EsygVcnwGcFQXLK5NTRL6SbfsUzPI0CZSI3GjcdRGXXP3FcgXB2RzdgYlthGdWm6 77ZmzDpyFrJbgdGcLLycTRsKEVFSKVsyt8JtG5IqIg3w== ARC-Authentication-Results: i=1; mx5.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: mx5.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 S1752874AbeBINmS (ORCPT ); Fri, 9 Feb 2018 08:42:18 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:49762 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752862AbeBINmQ (ORCPT ); Fri, 9 Feb 2018 08:42:16 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, David Woodhouse , Thomas Gleixner , Borislav Petkov , Dave Hansen , gnomes@lxorguk.ukuu.org.uk, ak@linux.intel.com, ashok.raj@intel.com, karahmed@amazon.de, arjan@linux.intel.com, torvalds@linux-foundation.org, peterz@infradead.org, bp@alien8.de, pbonzini@redhat.com, tim.c.chen@linux.intel.com, gregkh@linux-foundation.org Subject: [PATCH 4.9 43/92] x86/pti: Do not enable PTI on CPUs which are not vulnerable to Meltdown Date: Fri, 9 Feb 2018 14:39:12 +0100 Message-Id: <20180209133934.259299920@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: David Woodhouse (cherry picked from commit fec9434a12f38d3aeafeb75711b71d8a1fdef621) Also, for CPUs which don't speculate at all, don't report that they're vulnerable to the Spectre variants either. Leave the cpu_no_meltdown[] match table with just X86_VENDOR_AMD in it for now, even though that could be done with a simple comparison, on the assumption that we'll have more to add. Based on suggestions from Dave Hansen and Alan Cox. Signed-off-by: David Woodhouse Signed-off-by: Thomas Gleixner Reviewed-by: Greg Kroah-Hartman Reviewed-by: Borislav Petkov Acked-by: Dave Hansen Cc: gnomes@lxorguk.ukuu.org.uk Cc: ak@linux.intel.com Cc: ashok.raj@intel.com Cc: karahmed@amazon.de Cc: arjan@linux.intel.com Cc: torvalds@linux-foundation.org Cc: peterz@infradead.org Cc: bp@alien8.de Cc: pbonzini@redhat.com Cc: tim.c.chen@linux.intel.com Cc: gregkh@linux-foundation.org Link: https://lkml.kernel.org/r/1516896855-7642-6-git-send-email-dwmw@amazon.co.uk Signed-off-by: David Woodhouse Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/common.c | 48 ++++++++++++++++++++++++++++++++++++++----- 1 file changed, 43 insertions(+), 5 deletions(-) --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -44,6 +44,8 @@ #include #include #include +#include +#include #ifdef CONFIG_X86_LOCAL_APIC #include @@ -838,6 +840,41 @@ static void identify_cpu_without_cpuid(s #endif } +static const __initdata struct x86_cpu_id cpu_no_speculation[] = { + { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_CEDARVIEW, X86_FEATURE_ANY }, + { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_CLOVERVIEW, X86_FEATURE_ANY }, + { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_LINCROFT, X86_FEATURE_ANY }, + { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_PENWELL, X86_FEATURE_ANY }, + { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_PINEVIEW, X86_FEATURE_ANY }, + { X86_VENDOR_CENTAUR, 5 }, + { X86_VENDOR_INTEL, 5 }, + { X86_VENDOR_NSC, 5 }, + { X86_VENDOR_ANY, 4 }, + {} +}; + +static const __initdata struct x86_cpu_id cpu_no_meltdown[] = { + { X86_VENDOR_AMD }, + {} +}; + +static bool __init cpu_vulnerable_to_meltdown(struct cpuinfo_x86 *c) +{ + u64 ia32_cap = 0; + + if (x86_match_cpu(cpu_no_meltdown)) + return false; + + if (cpu_has(c, X86_FEATURE_ARCH_CAPABILITIES)) + rdmsrl(MSR_IA32_ARCH_CAPABILITIES, ia32_cap); + + /* Rogue Data Cache Load? No! */ + if (ia32_cap & ARCH_CAP_RDCL_NO) + return false; + + return true; +} + /* * Do minimum CPU detection early. * Fields really needed: vendor, cpuid_level, family, model, mask, @@ -884,11 +921,12 @@ static void __init early_identify_cpu(st setup_force_cpu_cap(X86_FEATURE_ALWAYS); - if (c->x86_vendor != X86_VENDOR_AMD) - setup_force_cpu_bug(X86_BUG_CPU_MELTDOWN); - - setup_force_cpu_bug(X86_BUG_SPECTRE_V1); - setup_force_cpu_bug(X86_BUG_SPECTRE_V2); + if (!x86_match_cpu(cpu_no_speculation)) { + if (cpu_vulnerable_to_meltdown(c)) + setup_force_cpu_bug(X86_BUG_CPU_MELTDOWN); + setup_force_cpu_bug(X86_BUG_SPECTRE_V1); + setup_force_cpu_bug(X86_BUG_SPECTRE_V2); + } fpu__init_system(c);