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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=no 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 DD1BFECE58D for ; Wed, 9 Oct 2019 08:04:11 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id AE478218AC for ; Wed, 9 Oct 2019 08:04:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="eWJQFQvh"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="Y8MtN5Ad" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AE478218AC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:In-Reply-To: Date:From:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:References: List-Owner; bh=1DKM2/goVMCx91L70qQpNyVIEfz3nq//1ovB+WCsduk=; b=eWJQFQvhLP+TQP bL3EV0Jkv1yxtUaOVjtNbX3G5T1gq0ct6awQOZxekLyj2jfjO1fBpkohcPTS3iRxejfjQ0bi7aHRS I14m4N6kBEN3qsN6PRHdAtGY1nW68jwvk2weKTj5sjb0O6Dm1zaGXlWZdqYuUdZ2vgUFVeGdAlq+3 GS72jObCBfpiOE2xq9ZNL+o3tv9wlE7Tt5Bo2ANnAc/EAwac6253DIcjDSGP8JJLl4FTVyRE8CecO bIs4CjCLN9u5hFXuGyw4aq3Vn+B+JRIMXJ8uuvzbhL43DpC+3Wwj95wAnLYk2TYIRtFgnGD7ZRm1+ ApW/63a6PrlzrSOQ+iKw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.2 #3 (Red Hat Linux)) id 1iI6x9-0003i4-8E; Wed, 09 Oct 2019 08:04:11 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.2 #3 (Red Hat Linux)) id 1iI6x2-0003hV-K6 for linux-arm-kernel@lists.infradead.org; Wed, 09 Oct 2019 08:04:09 +0000 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 694B0206B6; Wed, 9 Oct 2019 08:04:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570608243; bh=yGlugcxKzatg4rasq07g3PL14/ipljbOqrSMtUaFMls=; h=Subject:To:Cc:From:Date:In-Reply-To:From; b=Y8MtN5AdVtInXUNu3+RHa89tcK88TD6i7mZLObc/5/cMGy9iQR/2rCil0CgAxzkYd gxnB6uHIN9YOuTHW9xG1FSj1mRFbMIa3E9YIogJT0vl4lNxwckZ9A7IaLsH9Owxhtl joNc5zcWttC63YFY/FH3mQR4FA0Vx/SWGR4mUiPY= Subject: Patch "arm64: add sysfs vulnerability show for meltdown" has been added to the 4.19-stable tree To: andre.przywara@arm.com, ard.biesheuvel@linaro.org, catalin.marinas@arm.com, gregkh@linuxfoundation.org, jeremy.linton@arm.com, linux-arm-kernel@lists.infradead.org, stefan.wahren@i2se.com, suzuki.poulose@arm.com, will.deacon@arm.com From: Date: Wed, 09 Oct 2019 10:04:01 +0200 In-Reply-To: <20191008153930.15386-8-ard.biesheuvel@linaro.org> Message-ID: <157060824117478@kroah.com> MIME-Version: 1.0 X-stable: commit X-Patchwork-Hint: ignore X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191009_010407_587000_FF47E8DB X-CRM114-Status: GOOD ( 16.71 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: stable-commits@vger.kernel.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org This is a note to let you know that I've just added the patch titled arm64: add sysfs vulnerability show for meltdown to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: arm64-add-sysfs-vulnerability-show-for-meltdown.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >From foo@baz Wed 09 Oct 2019 10:02:11 AM CEST From: Ard Biesheuvel Date: Tue, 8 Oct 2019 17:39:21 +0200 Subject: arm64: add sysfs vulnerability show for meltdown To: linux-arm-kernel@lists.infradead.org Cc: stable@vger.kernel.org, Jeremy Linton , Suzuki K Poulose , Andre Przywara , Catalin Marinas , Stefan Wahren , Will Deacon , Ard Biesheuvel Message-ID: <20191008153930.15386-8-ard.biesheuvel@linaro.org> From: Jeremy Linton [ Upstream commit 1b3ccf4be0e7be8c4bd8522066b6cbc92591e912 ] We implement page table isolation as a mitigation for meltdown. Report this to userspace via sysfs. Signed-off-by: Jeremy Linton Reviewed-by: Suzuki K Poulose Reviewed-by: Andre Przywara Reviewed-by: Catalin Marinas Tested-by: Stefan Wahren Signed-off-by: Will Deacon Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kernel/cpufeature.c | 58 +++++++++++++++++++++++++++++++---------- 1 file changed, 44 insertions(+), 14 deletions(-) --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -889,7 +889,7 @@ static bool has_cache_dic(const struct a return ctr & BIT(CTR_DIC_SHIFT); } -#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 +static bool __meltdown_safe = true; static int __kpti_forced; /* 0: not forced, >0: forced on, <0: forced off */ static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry, @@ -908,6 +908,16 @@ static bool unmap_kernel_at_el0(const st { /* sentinel */ } }; char const *str = "command line option"; + bool meltdown_safe; + + meltdown_safe = is_midr_in_range_list(read_cpuid_id(), kpti_safe_list); + + /* Defer to CPU feature registers */ + if (has_cpuid_feature(entry, scope)) + meltdown_safe = true; + + if (!meltdown_safe) + __meltdown_safe = false; /* * For reasons that aren't entirely clear, enabling KPTI on Cavium @@ -919,6 +929,19 @@ static bool unmap_kernel_at_el0(const st __kpti_forced = -1; } + /* Useful for KASLR robustness */ + if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && kaslr_offset() > 0) { + if (!__kpti_forced) { + str = "KASLR"; + __kpti_forced = 1; + } + } + + if (!IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0)) { + pr_info_once("kernel page table isolation disabled by kernel configuration\n"); + return false; + } + /* Forced? */ if (__kpti_forced) { pr_info_once("kernel page table isolation forced %s by %s\n", @@ -926,18 +949,10 @@ static bool unmap_kernel_at_el0(const st return __kpti_forced > 0; } - /* Useful for KASLR robustness */ - if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) - return true; - - /* Don't force KPTI for CPUs that are not vulnerable */ - if (is_midr_in_range_list(read_cpuid_id(), kpti_safe_list)) - return false; - - /* Defer to CPU feature registers */ - return !has_cpuid_feature(entry, scope); + return !meltdown_safe; } +#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 static void kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused) { @@ -962,6 +977,12 @@ kpti_install_ng_mappings(const struct ar return; } +#else +static void +kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused) +{ +} +#endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */ static int __init parse_kpti(char *str) { @@ -975,7 +996,6 @@ static int __init parse_kpti(char *str) return 0; } early_param("kpti", parse_kpti); -#endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */ #ifdef CONFIG_ARM64_HW_AFDBM static inline void __cpu_enable_hw_dbm(void) @@ -1196,7 +1216,6 @@ static const struct arm64_cpu_capabiliti .field_pos = ID_AA64PFR0_EL0_SHIFT, .min_field_value = ID_AA64PFR0_EL0_32BIT_64BIT, }, -#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 { .desc = "Kernel page table isolation (KPTI)", .capability = ARM64_UNMAP_KERNEL_AT_EL0, @@ -1212,7 +1231,6 @@ static const struct arm64_cpu_capabiliti .matches = unmap_kernel_at_el0, .cpu_enable = kpti_install_ng_mappings, }, -#endif { /* FP/SIMD is not implemented */ .capability = ARM64_HAS_NO_FPSIMD, @@ -1853,3 +1871,15 @@ void cpu_clear_disr(const struct arm64_c /* Firmware may have left a deferred SError in this register. */ write_sysreg_s(0, SYS_DISR_EL1); } + +ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, + char *buf) +{ + if (__meltdown_safe) + return sprintf(buf, "Not affected\n"); + + if (arm64_kernel_unmapped_at_el0()) + return sprintf(buf, "Mitigation: PTI\n"); + + return sprintf(buf, "Vulnerable\n"); +} Patches currently in stable-queue which might be from ard.biesheuvel@linaro.org are queue-4.19/arm64-add-sysfs-vulnerability-show-for-meltdown.patch queue-4.19/arm64-force-ssbs-on-context-switch.patch queue-4.19/arm64-enable-generic-cpu-vulnerabilites-support.patch queue-4.19/arm64-provide-a-command-line-to-disable-spectre_v2-mitigation.patch queue-4.19/arm64-always-enable-spectre-v2-vulnerability-detection.patch queue-4.19/arm64-docs-document-ssbs-hwcap.patch queue-4.19/arm64-add-sysfs-vulnerability-show-for-spectre-v1.patch queue-4.19/arm64-add-sysfs-vulnerability-show-for-speculative-store-bypass.patch queue-4.19/kvm-arm64-set-sctlr_el2.dssbs-if-ssbd-is-forcefully-disabled-and-vhe.patch queue-4.19/arm64-always-enable-ssb-vulnerability-detection.patch queue-4.19/arm64-advertise-mitigation-of-spectre-v2-or-lack-thereof.patch queue-4.19/arm64-ssbs-don-t-treat-cpus-with-ssbs-as-unaffected-by-ssb.patch queue-4.19/crypto-skcipher-unmap-pages-after-an-external-error.patch queue-4.19/arm64-cpufeature-detect-ssbs-and-advertise-to-userspace.patch queue-4.19/arm64-ssbd-add-support-for-pstate.ssbs-rather-than-trapping-to-el3.patch queue-4.19/arm64-fix-ssbs-sanitization.patch queue-4.19/arm64-add-sysfs-vulnerability-show-for-spectre-v2.patch _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel