From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-3218881-1519790496-2-1160444775918391003 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 0.249, 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='CN', FromHeader='org', MailFrom='org' X-Spam-charsets: 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=1519790496; b=OGIQCQXHze/4pt5WmnyGMKBPkadyvR/bAsFVFEcczHM7eKw BLiN9OuLUfsE/UrBxIT27tARyUCVoj4LVWaNQYKF31ozkVXqhbW01KWzR3OmMZXl wQ+8gcKds5CuQn9GEMQr61x46gyJBjkcCqc7vQZ33Dz3ZgR0RPwhXtJgwHmFSS2m 3m2BPGLAmW+9nzPQ72hEtMwsj6mCGSb5yf2675FzHH7pvgHz00SKv5cu5bPBS4ZH 7a+76DSaLZoSAPZeS8jxIr/hH+AN0P7hISsZfhfB3/rFDDJ1i9wUUMeF9oXWor9/ AMnhF+Cz1o2fyNMQtf5uXmXO3E9+wl3AREBk6RQ== 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:sender:list-id; s=arctest; t=1519790496; bh=61Y8iHNGS/LyzooAj6849j03LY7srEwVDjkJR8E93VM=; b=b+7SkRX4B8T9 wU5xUuxn9U2VeBCOatLQRcPU/q4NP0x4phF1kvlJM1E7v9V+u431Jq5Mg+lLoY1e wrmWxJTvxlRMzz/pQZ96dpRJYo55NQNtRDi04J9rSyL48p3gQi68H/qai7D0VGDh QGm+Gw2Q/I+dvQlYoCyrztuQ7qpKBUJVTC3Sr8g28FmY/cv0/1RnE6nEF1lGkgdt X9xr/DJtD32dklUsMYSCoSIAGJN1CJgHySJzCjJMO/txWKuGNBC/YfIRNBCL2/p6 xUl4C4pr65lZB2QDOwjgZt59tP4lrjak5hpTW6YZnMZ63E64fVP9J680Tt6EbQlN GVfEqDZFFw== ARC-Authentication-Results: i=1; mx5.messagingengine.com; arc=none (no signatures found); dkim=pass (1024-bit rsa key sha256) header.d=linaro.org header.i=@linaro.org header.b=dNmpN4p3 x-bits=1024 x-keytype=rsa x-algorithm=sha256 x-selector=google; dmarc=pass (p=none,has-list-id=yes,d=none) header.from=linaro.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-google-dkim=pass (2048-bit rsa key) header.d=1e100.net header.i=@1e100.net header.b=pGz1zpkq; 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=linaro.org header.result=pass header_is_org_domain=yes Authentication-Results: mx5.messagingengine.com; arc=none (no signatures found); dkim=pass (1024-bit rsa key sha256) header.d=linaro.org header.i=@linaro.org header.b=dNmpN4p3 x-bits=1024 x-keytype=rsa x-algorithm=sha256 x-selector=google; dmarc=pass (p=none,has-list-id=yes,d=none) header.from=linaro.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-google-dkim=pass (2048-bit rsa key) header.d=1e100.net header.i=@1e100.net header.b=pGz1zpkq; 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=linaro.org header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752409AbeB1EAw (ORCPT ); Tue, 27 Feb 2018 23:00:52 -0500 Received: from mail-pg0-f65.google.com ([74.125.83.65]:46707 "EHLO mail-pg0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752403AbeB1EAu (ORCPT ); Tue, 27 Feb 2018 23:00:50 -0500 X-Google-Smtp-Source: AH8x224sO3tK3v8mdNzockHnBxio9++P4ASCw19fhUjfOLeViSJe33kzC/OOReUREt2fmAZOGvnfqg== From: Alex Shi To: Marc Zyngier , Will Deacon , Ard Biesheuvel , Catalin Marinas , stable@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Alex Shi Subject: [PATCH 27/29] arm64: Force KPTI to be disabled on Cavium ThunderX Date: Wed, 28 Feb 2018 11:56:49 +0800 Message-Id: <1519790211-16582-28-git-send-email-alex.shi@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1519790211-16582-1-git-send-email-alex.shi@linaro.org> References: <1519790211-16582-1-git-send-email-alex.shi@linaro.org> 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: From: Marc Zyngier commit 6dc52b15c4a4 upstream. Cavium ThunderX's erratum 27456 results in a corruption of icache entries that are loaded from memory that is mapped as non-global (i.e. ASID-tagged). As KPTI is based on memory being mapped non-global, let's prevent it from kicking in if this erratum is detected. Signed-off-by: Marc Zyngier [will: Update comment] Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas Signed-off-by: Alex Shi Conflicts: using old function read_system_reg/cpus_have_cap to replace read_sanitised_ftr_reg/cpus_have_const_cap in arch/arm64/kernel/cpufeature.c --- arch/arm64/kernel/cpufeature.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 0fba610..760c851 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -753,12 +753,23 @@ 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, int __unused) { + char const *str = "command line option"; u64 pfr0 = read_system_reg(SYS_ID_AA64PFR0_EL1); - /* Forced on command line? */ + /* + * For reasons that aren't entirely clear, enabling KPTI on Cavium + * ThunderX leads to apparent I-cache corruption of kernel text, which + * ends as well as you might imagine. Don't even try. + */ + if (cpus_have_cap(ARM64_WORKAROUND_CAVIUM_27456)) { + str = "ARM64_WORKAROUND_CAVIUM_27456"; + __kpti_forced = -1; + } + + /* Forced? */ if (__kpti_forced) { - pr_info_once("kernel page table isolation forced %s by command line option\n", - __kpti_forced > 0 ? "ON" : "OFF"); + pr_info_once("kernel page table isolation forced %s by %s\n", + __kpti_forced > 0 ? "ON" : "OFF", str); return __kpti_forced > 0; } -- 2.7.4