From patchwork Wed Jan 9 23:55:43 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeremy Linton X-Patchwork-Id: 10754999 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 025B36C5 for ; Wed, 9 Jan 2019 23:57:29 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E245529289 for ; Wed, 9 Jan 2019 23:57:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D393C29307; Wed, 9 Jan 2019 23:57:28 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 437CC29289 for ; Wed, 9 Jan 2019 23:57:28 +0000 (UTC) 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:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: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=9LylZ6FS4SwBTAI+MQz04AvoeT7Ed12EJT/qO7ZT8sQ=; b=KeyfaR/UuvvpXDWDZIypFSjaVX zt+U6jKBG/yWTsDCHPOe0OTAZyoOiOcnaJmvl6ta3cKZdZVLHZzXvkQIvITDsULKULNyWoWtrisHJ yU5oeUQRZvw27kjPAKsU047MwdD8lmR1jRaUMl40RQcofNMZZHSZrRJ/C7cTbzi2dipstICPOso4k o04j9siEf24Ke40Ziw5Mk9FevBJc30c+yORauZU9e0MJrVO0P/Hyk4c/BUwzo/YDlCrbP2RRym25B 1TZoGpeQe5CUGxf2tOA8EINoaPuQhsKmMrtJaJIbrBTUlm8u2qQ5hRh3Kh2QKP2uuppwpbuCaYgxv Ld6z00tQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1ghNiv-0007Pl-JT; Wed, 09 Jan 2019 23:57:25 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1ghNhV-00061X-QC for linux-arm-kernel@lists.infradead.org; Wed, 09 Jan 2019 23:56:06 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 71001165C; Wed, 9 Jan 2019 15:55:57 -0800 (PST) Received: from beelzebub.austin.arm.com (beelzebub.austin.arm.com [10.118.12.119]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id C9AAA3F5AF; Wed, 9 Jan 2019 15:55:56 -0800 (PST) From: Jeremy Linton To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v3 6/7] arm64: add sysfs vulnerability show for speculative store bypass Date: Wed, 9 Jan 2019 17:55:43 -0600 Message-Id: <20190109235544.2992426-7-jeremy.linton@arm.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20190109235544.2992426-1-jeremy.linton@arm.com> References: <20190109235544.2992426-1-jeremy.linton@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190109_155558_321621_E6481943 X-CRM114-Status: GOOD ( 13.03 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: stefan.wahren@i2se.com, mlangsdo@redhat.com, suzuki.poulose@arm.com, marc.zyngier@arm.com, catalin.marinas@arm.com, julien.thierry@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, Jeremy Linton , steven.price@arm.com, ykaukab@suse.de, dave.martin@arm.com, shankerd@codeaurora.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Return status based on ssbd_state and the arm64 SSBS feature. If the mitigation is disabled, or the firmware isn't responding then return the expected machine state based on a new blacklist of known vulnerable cores. Signed-off-by: Jeremy Linton --- arch/arm64/kernel/cpu_errata.c | 48 ++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index ee286d606d9b..c8ff96158b94 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -288,6 +288,7 @@ enable_smccc_arch_workaround_1(const struct arm64_cpu_capabilities *entry) DEFINE_PER_CPU_READ_MOSTLY(u64, arm64_ssbd_callback_required); int ssbd_state __read_mostly = ARM64_SSBD_KERNEL; +static bool __ssb_safe = true; static const struct ssbd_options { const char *str; @@ -385,10 +386,18 @@ static bool has_ssbd_mitigation(const struct arm64_cpu_capabilities *entry, { struct arm_smccc_res res; bool required = true; + bool is_vul; s32 val; WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible()); + is_vul = is_midr_in_range_list(read_cpuid_id(), entry->midr_range_list); + + if (is_vul) + __ssb_safe = false; + + arm64_requested_vuln_attrs |= VULN_SSB; + if (this_cpu_has_cap(ARM64_SSBS)) { required = false; goto out_printmsg; @@ -422,6 +431,7 @@ static bool has_ssbd_mitigation(const struct arm64_cpu_capabilities *entry, ssbd_state = ARM64_SSBD_UNKNOWN; return false; + /* machines with mixed mitigation requirements must not return this */ case SMCCC_RET_NOT_REQUIRED: pr_info_once("%s mitigation not required\n", entry->desc); ssbd_state = ARM64_SSBD_MITIGATED; @@ -476,6 +486,17 @@ static bool has_ssbd_mitigation(const struct arm64_cpu_capabilities *entry, return required; } + +/* known vulnerable cores */ +static const struct midr_range arm64_ssb_cpus[] = { + MIDR_ALL_VERSIONS(MIDR_CORTEX_A57), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A72), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A73), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A75), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A76), + {}, +}; + #endif /* CONFIG_ARM64_SSBD */ static void __maybe_unused @@ -762,6 +783,7 @@ const struct arm64_cpu_capabilities arm64_errata[] = { .capability = ARM64_SSBD, .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, .matches = has_ssbd_mitigation, + .midr_range_list = arm64_ssb_cpus, }, #endif #ifdef CONFIG_ARM64_ERRATUM_1188873 @@ -809,4 +831,30 @@ ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr, return sprintf(buf, "Vulnerable\n"); } +ssize_t cpu_show_spec_store_bypass(struct device *dev, + struct device_attribute *attr, char *buf) +{ + /* + * Two assumptions: First, get_ssbd_state() reflects the worse case + * for hetrogenous machines, and that if SSBS is supported its + * supported by all cores. + */ + switch (arm64_get_ssbd_state()) { + case ARM64_SSBD_MITIGATED: + return sprintf(buf, "Not affected\n"); + + case ARM64_SSBD_KERNEL: + case ARM64_SSBD_FORCE_ENABLE: + if (cpus_have_cap(ARM64_SSBS)) + return sprintf(buf, "Not affected\n"); + return sprintf(buf, + "Mitigation: Speculative Store Bypass disabled\n"); + } + + if (__ssb_safe) + return sprintf(buf, "Not affected\n"); + + return sprintf(buf, "Vulnerable\n"); +} + #endif