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=-6.8 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,URIBL_BLOCKED,USER_AGENT_GIT 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 85EF1C4360C for ; Thu, 10 Oct 2019 08:50:42 +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 55E1D21929 for ; Thu, 10 Oct 2019 08:50:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="aJeP2KP+"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="siq/iEVa" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 55E1D21929 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:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=eXpX2cgczGDpD2M24uxD0z2JVg++Usas5gTcEoiC2sk=; b=aJeP2KP+fo3Rev Tx9moHy10hQ4VNmIUdVzaomUNYt3aK9IQKHmyOy3aD4qQ70qmMwCztWkzqlm8u1t9BXEgLnASmbdk YHp2tjF9KmgyeSwqHl0YXTOTURKYn7OXUg/YciButs/NOTBfuzRKejwpaHG4eNR6IK3kpsR2thtl5 fBhW2OBNjOLsOQ5uEWfEodAFEAKAtMBCwg+XcU5RfsPscXKrza5SFesmEPXjBJRboUBy4YJwghfJB DxV95GwNxAlyZ9jp/SiGidWQLkhBuzN6chqK0Kdd5MT1Ke6cCXW5KQagEfsGUghVKJbW3CWkCBnJ9 k+7LUJEjpPcDzncm+nGg==; 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 1iIU9a-0007U9-Ql; Thu, 10 Oct 2019 08:50:34 +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 1iIU7l-00045A-LC for linux-arm-kernel@lists.infradead.org; Thu, 10 Oct 2019 08:48:43 +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 B833121929; Thu, 10 Oct 2019 08:48:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570697321; bh=IyVvloWswiwb0rHjj5ssPaCzfOBHQsDBo6CZ5n2dG7o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=siq/iEVaQlSVNtjn/p3JBKEpbkKzNDmrrbS7Dr4V1H7jjz8KRLH4VupRd166e8NFu Vwb73Y4t4AicllntYTo4FFd15md9UrqbGoHVjsb4/D99gUkNfK1Lf9rcs5a++o0PNI MqBk/LxYP9i3uN1NrsznUHgYLT6pOprpY7G/ahxs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH 4.19 100/114] arm64: add sysfs vulnerability show for spectre-v2 Date: Thu, 10 Oct 2019 10:36:47 +0200 Message-Id: <20191010083613.477591447@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191010083544.711104709@linuxfoundation.org> References: <20191010083544.711104709@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191010_014841_747872_22F56F82 X-CRM114-Status: GOOD ( 13.46 ) 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: Stefan Wahren , Ard Biesheuvel , Greg Kroah-Hartman , Will Deacon , Jeremy Linton , Andre Przywara , stable@vger.kernel.org, Catalin Marinas 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 From: Jeremy Linton [ Upstream commit d2532e27b5638bb2e2dd52b80b7ea2ec65135377 ] Track whether all the cores in the machine are vulnerable to Spectre-v2, and whether all the vulnerable cores have been mitigated. We then expose this information to userspace via sysfs. Signed-off-by: Jeremy Linton 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/cpu_errata.c | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -480,6 +480,10 @@ has_cortex_a76_erratum_1463225(const str .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, \ CAP_MIDR_RANGE_LIST(midr_list) +/* Track overall mitigation state. We are only mitigated if all cores are ok */ +static bool __hardenbp_enab = true; +static bool __spectrev2_safe = true; + /* * Generic helper for handling capabilties with multiple (match,enable) pairs * of call backs, sharing the same capability bit. @@ -522,6 +526,10 @@ static const struct midr_range spectre_v { /* sentinel */ } }; +/* + * Track overall bp hardening for all heterogeneous cores in the machine. + * We are only considered "safe" if all booted cores are known safe. + */ static bool __maybe_unused check_branch_predictor(const struct arm64_cpu_capabilities *entry, int scope) { @@ -543,6 +551,8 @@ check_branch_predictor(const struct arm6 if (!need_wa) return false; + __spectrev2_safe = false; + if (!IS_ENABLED(CONFIG_HARDEN_BRANCH_PREDICTOR)) { pr_warn_once("spectrev2 mitigation disabled by kernel configuration\n"); __hardenbp_enab = false; @@ -552,11 +562,14 @@ check_branch_predictor(const struct arm6 /* forced off */ if (__nospectre_v2) { pr_info_once("spectrev2 mitigation disabled by command line option\n"); + __hardenbp_enab = false; return false; } - if (need_wa < 0) + if (need_wa < 0) { pr_warn_once("ARM_SMCCC_ARCH_WORKAROUND_1 missing from firmware\n"); + __hardenbp_enab = false; + } return (need_wa > 0); } @@ -753,3 +766,15 @@ ssize_t cpu_show_spectre_v1(struct devic { return sprintf(buf, "Mitigation: __user pointer sanitization\n"); } + +ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr, + char *buf) +{ + if (__spectrev2_safe) + return sprintf(buf, "Not affected\n"); + + if (__hardenbp_enab) + return sprintf(buf, "Mitigation: Branch predictor hardening\n"); + + return sprintf(buf, "Vulnerable\n"); +} _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel