From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-3071467-1517855015-2-17576840224675717680 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 enfrro, 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=1517855015; b=Kw3Vzw+uR9X0NKArrAnJmMHBlP463sFoi7YBI5UObG+usLe zwjA4Hq5Jt3SgZjfUyg4RFObwa9CaHC4YNVEHw7I2K/52EWxC1yCM8QeQRQp7wm/ 5sFYZ4bYdxTPsWuPUc/Oq4ubvvT8Xg/R1GQumPooNY8CsJCV0hl4M53CZYj9D/Ij XX2EUhflQnFT7qKOuMF4WgUkCuIy4DlExDHyQsB2E0GzwM8h6QGXfb7AQEn3A2ak uYzMGEei5cpgNdis8OkTzZcjd/iSNBKNcJxyNw3bghKx5CdKXCtmkE5TrpicuAv/ UTkywpRQEzyQ3IoTuOjTMnUDLFdFWltcxN/vj3g== 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=1517855015; bh=VlWrIoWlfdDTft5/U35CLNMAMN Bi1fmv4wsoMN/IARA=; b=rnzE+YErXKVAwWkLwcWxtlOcegdtU6GmPV/sLa3tRv TsWD3K95oQIHjOlNqWPBfMpIjOXhD9tyI4/Q6dpRNIjM8CnOyL5GTIYV5T0tK9kE k8IgrCFGYrmEAh5KI+OKxec0J49kMEy+bdUPZH/T2xIbumGlmokQipyJeVvOVq8S 8t9BQmUvDqOUQIQknP9XkMDKjCJg4IdOOvlFasZ8OdCjmbdibmOXq4CUm2iLgpye G3Ero4GmWRhwfHKy7JUeZd28rQWuytRNbmSB0IETDdCtm5Pj/iSrahxEzIPy69Gx tqx1EFQlAnvgyEPzp0qlOUNrGEmIyhuMpleH/n+czZCA== 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 S1752999AbeBESXc (ORCPT ); Mon, 5 Feb 2018 13:23:32 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:50824 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753363AbeBESXa (ORCPT ); Mon, 5 Feb 2018 13:23:30 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, KarimAllah Ahmed , David Woodhouse , gnomes@lxorguk.ukuu.org.uk, ak@linux.intel.com, ashok.raj@intel.com, dave.hansen@intel.com, 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 4.14 14/64] x86/speculation: Add basic IBPB (Indirect Branch Prediction Barrier) support Date: Mon, 5 Feb 2018 10:22:33 -0800 Message-Id: <20180205182139.157163812@linuxfoundation.org> X-Mailer: git-send-email 2.16.1 In-Reply-To: <20180205182138.571333346@linuxfoundation.org> References: <20180205182138.571333346@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: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: David Woodhouse dwmw@amazon.co.uk commit 20ffa1caecca4db8f79fe665acdeaa5af815a24d Expose indirect_branch_prediction_barrier() for use in subsequent patches. [ tglx: Add IBPB status to spectre_v2 sysfs file ] Co-developed-by: KarimAllah Ahmed Signed-off-by: KarimAllah Ahmed Signed-off-by: David Woodhouse Cc: gnomes@lxorguk.ukuu.org.uk Cc: ak@linux.intel.com Cc: ashok.raj@intel.com Cc: dave.hansen@intel.com 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/1516896855-7642-8-git-send-email-dwmw@amazon.co.uk Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/cpufeatures.h | 2 ++ arch/x86/include/asm/nospec-branch.h | 13 +++++++++++++ arch/x86/kernel/cpu/bugs.c | 10 +++++++++- 3 files changed, 24 insertions(+), 1 deletion(-) --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -210,6 +210,8 @@ #define X86_FEATURE_MBA ( 7*32+18) /* Memory Bandwidth Allocation */ #define X86_FEATURE_RSB_CTXSW ( 7*32+19) /* Fill RSB on context switches */ +#define X86_FEATURE_IBPB ( 7*32+21) /* Indirect Branch Prediction Barrier enabled*/ + /* Virtualization flags: Linux defined, word 8 */ #define X86_FEATURE_TPR_SHADOW ( 8*32+ 0) /* Intel TPR Shadow */ #define X86_FEATURE_VNMI ( 8*32+ 1) /* Intel Virtual NMI */ --- a/arch/x86/include/asm/nospec-branch.h +++ b/arch/x86/include/asm/nospec-branch.h @@ -218,5 +218,18 @@ static inline void vmexit_fill_RSB(void) #endif } +static inline void indirect_branch_prediction_barrier(void) +{ + asm volatile(ALTERNATIVE("", + "movl %[msr], %%ecx\n\t" + "movl %[val], %%eax\n\t" + "movl $0, %%edx\n\t" + "wrmsr", + X86_FEATURE_IBPB) + : : [msr] "i" (MSR_IA32_PRED_CMD), + [val] "i" (PRED_CMD_IBPB) + : "eax", "ecx", "edx", "memory"); +} + #endif /* __ASSEMBLY__ */ #endif /* __NOSPEC_BRANCH_H__ */ --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -263,6 +263,13 @@ retpoline_auto: setup_force_cpu_cap(X86_FEATURE_RSB_CTXSW); pr_info("Filling RSB on context switch\n"); } + + /* Initialize Indirect Branch Prediction Barrier if supported */ + if (boot_cpu_has(X86_FEATURE_SPEC_CTRL) || + boot_cpu_has(X86_FEATURE_AMD_PRED_CMD)) { + setup_force_cpu_cap(X86_FEATURE_IBPB); + pr_info("Enabling Indirect Branch Prediction Barrier\n"); + } } #undef pr_fmt @@ -292,7 +299,8 @@ ssize_t cpu_show_spectre_v2(struct devic if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V2)) return sprintf(buf, "Not affected\n"); - return sprintf(buf, "%s%s\n", spectre_v2_strings[spectre_v2_enabled], + return sprintf(buf, "%s%s%s\n", spectre_v2_strings[spectre_v2_enabled], + boot_cpu_has(X86_FEATURE_IBPB) ? ", IPBP" : "", spectre_v2_bad_module ? " - vulnerable module loaded" : ""); } #endif